что это такое, температура плавления, с канифолью, бессвинцовый, ПОС, сплав, оловянный, РОЗЕ – Оборудование для пайки на Svarka.guru

При изготовлении и ремонте электротехники постоянно требуются навыки обращения с паяльником, а для спайки используют припой и канифоль, в середине прошлого века для этих целей использовалось олово, но не в чистом виде, т. к. это весьма дорогое удовольствие, а сплавы с другими легкоплавкими металлами.

Какие встречаются?

Что же такое припой и как надо правильно его выбирать — на практике они могут быть мягкими или твёрдыми. Монтаж любой радиоэлектронной аппаратуры происходит с применением легкоплавких вариантов.

Компоненты неизвестного происхождения отличается по следующим признакам:

1. Насыщенный блеск среза говорит о высоком присутствии олова.
2. Преобладание свинца гарантирует субстанции тускло-серый цвет и матовую поверхность.
3. При повышенном содержании свинца изделие становится пластичным, например, проволока сечением в 6 мм без видимого услия сгибается руками.

Иногда для качественной пайки применяется уже готовая смесь — это припой в виде проволоки, а флюс запаян внутри. Производители изготавливают аналогичные субстанции с допуском флюса в пределах 1—3% от общего веса, что благоприятно сказывается на процессе пайки и увеличивает производительность труда, т. к. отпадает необходимость постоянно макать жало паяльника в баночку с флюсом.

По консистенции выпускаются двух видов: мягкий или твердый припой, а по температуре плавления различают обыкновенные и тугоплавкие типы.

Основные свойства

Смачиваемость пайки

Такой термин означает сцепление молекул жидкого расплава с твёрдой поверхностью, от степени которой зависит текучесть пайки. Для хорошей пайки жидкий припой качественно смачивает поверхность, где происходит пайка, а граница его образует острый угол.

Высохший флюс удаляется только при помощи механической зачистки, потому что появился дополнительный сплав. Если капля расплавленного вещества образует тупой угол с поверхностью, то это указывает на неудовлетворительное качество смачивания, которому противодействуют загрязнения, жировые пятна или оксидная плёнка металла.

Варианты смачиваемости поверхности пайки расплавленным флюсом.

Температура плавления

Основной критерий выбора качественных сплавов заключается в том, что они должны приходить в жидкое состояние раньше, чем соединяемые структуры, при этом температура плавления припоя существенно отличается от аналогичного показателя другого вида, например, имеющего в составе примеси свинца.

Наличие разных примесей влияет на способность плавиться при одинаковой температуре, например, ПОС-40 расплавляется при достижении 238 ⁰С, но встречаются тугоплавкие припои и для их плавления применяются специальные приспособления.

Низкотемпературные варианты

На первом месте находится сплав ВУДА с составом: по 10% Sn и Cd, по 40% Pb и Bi, начало расплава — 65—72 ⁰C.  Вторую позицию занимает припой под названием РОЗЕ, которых начинает плавиться при 90—94 ⁰C. Состоит: по 25% олова и свинца, а остальные 50% занимает висмут. Вышеперечисленные сплавы относятся к дорогим припоям.

Третье место среди низкотемпературных изделий занимает ПОСК-50-18, с температурой 142—145 ⁰С. В состав этого припоя входит 50% олова, 32% свинца и 18% кадмия, что усиливает сопротивляемость коррозии, но добавляет ему токсичность.

Большую популярность у радиолюбителей имеет второй номинант (под названием РОЗЕ), но в отечественной радиоэлектронике его маркировка — ПОСВ-50, где цифры — это процент висмута. Применяется для монтажа/демонтажа и лужения чувствительных к перегреву дорожек из меди на печатных платах.

Марки мягкого вида

Припой для пайки из этой категории применяется с уже готовым флюсом, находящимся внутри проволоки, поэтому расплавление происходит одновременно. Большое распространение получило изделие с названием Третник, потому что в нём содержится треть свинца от общей величины состава. Олово, входящее в состав сплава для пайки, отличается чистой в плане экологии, поэтому разрешается применение этого вида в пищевой промышленности.

Мягкие виды припоев применяются для пайки деталей, боящихся перегрева, например: транзисторов или предохранителей. Сплав ВУДА из-за токсичности применяется в ограниченных сферах человеческой деятельности.

Отечественные сплавы маркируются аббревиатурой ПОС, но при наличии других веществ в конце добавляется буква, соответствующая названию, например, ПОСВ-33 — этот припой содержит равные части олова, свинца и висмута.

Основные технические параметры

Материалы для пайки разделяют по таким параметрам:

1. Проводимость, например, припои с содержанием алюминия обладают лучшими аналогичными значениями, нежели с маркировкой ПОС.
2. Прочность на усилие растяжения, единица измерения кг/мм. Этот параметр напрямую зависит от процентного содержания олова.
3. Температура плавления, которая зависит химического состава.

Таблица зависимости температуры и применения от химического состава припоя.

Флюс

В продаже распространён припой с канифолью в виде полой проволоки, свитой кольцами. Аналогичного состава флюс производится из хвойных деревьев, такая субстанция приходит в мягкое состояние при нагревании до 50 °С, а при 250 °C — начинает кипеть с частичным испарением. Канифоль нужно обязательно удалять после окончания работ, иначе произойдёт окисление, а субстанция, впитывая влагу из воздуха, начнёт препятствовать исправной работе приборов.

Популярные составы

Существуют три основных категории:

1. Светлого цвета канифоль применяют при соединении меди и других мягких цветных металлов; спиртовой раствор с концентрацией один к пяти применяют в труднодоступном месте спайки; а смесь глицерина и канифоли применяют для герметичной пайки.
2. Флюсы, включающие спирт, вазелин или хлористый цинк, используются для прочного соединения цветных и драгоценных металлов. Применение пасты оправдано тем, что её удобнее наносить в требуемом количестве на изделие.
3. Кислотно активные вещества производятся в жидком виде, например, ортофосфорная кислота, имеющая плотность 1,7.

Хранить жидкие флюсы надо в герметически закрывающихся ёмкостях, для исключения испарения.

Пастообразные

Большое распространение получила паста Тиноль, которая применяется для пайки разных изделий в труднодоступных местах. Наносится лопаткой, с последующим активным нагреванием паяльником или другим, более мощным электрическим инструментом. Часто используется неопытными исполнителями, у которых нет навыков в работе с оловом и канифолью.

Использование ПОС

Первооткрыватели этого сплава были приятно удивлены, что он превращается в расплавленное состояние при меньшей температуре, а эвтектическая смесь способна играть роль растворителя для добавленного металла. Так и были разработаны самые первые марки припоев ПОС.

Свинцовые варианты

Такие смеси с содержанием свинца, отличаются мягкостью, быстрым расплавлением и лёгкой обработкой, поэтому получили название свинецсодержащие припои. Они вредны, поэтому были запрещены для использования во время спайки элементов электрических приборов по всему миру. Процент содержание кадмия, ртути, а также аналогичных вредоносных компонентов в оборудовании строго регламентировано и проверяется соответствующими организациями.

Без содержания свинца

Бессвинцовый припой не должен содержать вредного металла и считается экологически чистым, не причиняющим вреда окружающей среде и исполнителям работ по пайке. Простейшим примером служит припой оловянный, который содержит чистое олово, имеет повышенную смачиваемость и высокую электропроводность. Для борьбы с недостатками, в них добавляют медь, серебро и золото, что помогает сделать субстанцию более твёрдой.

У такого изделия повышается температура расплавления, но найти полную альтернативу стандартным видам припоя пока что не удаётся, но основным показателем является безвредность. Олово занимает главное место в химическом составе, поэтому присущие ему свойства оказывают большое влияние на припой, из-за этого температура плавления у бессвинцового припоя ниже, а материал получается более мягким.

В. И. Блинов, образование ПТУ, специальность сварщик шестого разряда, допуск от НАКС к НГДО и ГО, опыт работы с 2004 года: «При отсутствии подходящего по всем параметрам варианта, во время пайки используйте марку ПСР-45, в которой содержание вредного свинца минимальное и составляет не более 0,5% от общего веса».

Колофонская смола

Именно так называется общеизвестная канифоль — аморфное вещество с характерным изломом и стеклянным блеском сколов. Кроме того, что она обладает природным свойством диэлектрика, известны и такие особенности:

• хорошо растворяется в бензине, спирте, эфире и ацетоне, но остаётся безразличной к воздействию воды;
• температура плавления варьируется в пределах 50—70 градусов, но иногда повышается до 130 ⁰C;
• в химическом составе присутствует до 90% смоляных кислот, основой является абиетиновая кислота;
• легко разрушается при незначительном механическом воздействии.

Цвет изменяется от светло-жёлтого до тёмно-бурого оттенков, что зависит от степени очистки и указывает на количество посторонних примесей. Отличные электроизоляционные свойства принадлежат смоле с лимонным окрасом.

Секреты выбора

Задача любого исполнителя состоит в создании крепкого и надёжного закрепления на плате радиодеталей, поэтому подбор припоя выполняется согласно следующим параметрам:

1. Состав материалов, подвергающихся пайке — здесь надо учитывать характеристики материала, его способность к перегреву и многое другое.
2. При пайке проводов или других крупных предметов применяются тугоплавкие припои.
3. Иногда нужно применить припой, обладающий высокой способностью к проведению электрического тока, надо учитывать, что сопротивление олова намного меньше, чем у свинца, поэтому для спайки высокочастотных плат применяют дорогостоящие марки припоя.

В каждой конкретной ситуации исполнитель должен чётко знать соответствие припоя и соединяемого изделия, чтобы выбрать оптимальный вариант для качественной пайки.

Выводы

Сегодня в продаже встречается изобилие разных припоев, как говорится, на все случаи жизни, но выбирать следует проверенные образцы, которые помогут спаять изделие качественно и с высокой надёжностью при эксплуатации.

Припой — это… Что такое Припой?

Катушка оловянно-свинцового припоя

Припой — металл или сплав, применяемый при пайке для соединения заготовок и имеющий температуру плавления ниже, чем соединяемые металлы. Применяют сплавы на основе олова, свинца, кадмия, меди, никеля и др.

Пайку осуществляют или с целью создания механически прочного (иногда герметичного) шва, или для получения электрического контакта с малым переходным сопротивлением. При пайке места соединения и припой нагревают. Так как припой имеет температуру плавления значительно ниже, чем соединяемый металл (или металлы), то он плавится, в то время как основной металл остаётся твёрдым. На границе соприкосновения расплавленного припоя и твёрдого металла происходят различные физико-химические процессы. Припой смачивает металл, растекается по нему и заполняет зазоры между соединяемыми деталями. При этом компоненты припоя диффундируют в основной металл, основной металл растворяется в припое, в результате чего образуется промежуточная прослойка, которая после застывания соединяет детали в одно целое.

Выбирают припой с учётом физико-химических свойств соединяемых металлов, требуемой механической прочности спая, его коррозионной устойчивости и стоимости. При пайке токоведущих частей необходимо учитывать удельную проводимость припоя.

Классификация припоев

Припои принято делить на две группы — мягкие и твёрдые. К мягким относятся припои с температурой плавления до 300 °C, к твёрдым — выше 300 °C. Кроме того, припои существенно различаются по механической прочности. Мягкие припои имеют предел прочности при растяжении 16—100 МПа, а твёрдые — 100—500МПа.

Мягкими припоями являются оловянно-свинцовые сплавы (ПОС) с содержанием олова от 10 (ПОС-10) до 90% (ПОС-90), остальное свинец. Проводимость этих припоев составляет 9—15% чистой меди. Большое количество оловянно-свинцовых припоев содержит небольшой процент сурьмы (такие припои обозначаются ПОССу).

Температура плавления ПОС:

ПОС15 — 280’C.

ПОС25 — 260’C.

ПОС33 — 247’C.

ПОС40 — 235’C.

ПОС64 — 183’C.

ПОС90 — 220’C.

Наиболее распространёнными твёрдыми припоями является медно-цинковые (ПМЦ) и серебряные (ПСр) с различными добавками.

Температуры плавления ПСр и ПМЦ:

ПСр10 — 830’С.

ПСр12 — 785’С.

ПСр25 — 765’С.

ПСр45 — 720’С.

ПСр65 — 740’С.

ПСр70 — 780’С.

ПМЦ36 — 825’С.

ПМЦ42 — 833’С.

ПМЦ51 — 870’С

Появление гибридной технологии для создания электронных плат обусловило появление нового типа припоев: так называемых паяльных паст, пригодных как для обычной, так и трафаретной пайки элементов гибридных схем. Паяльные пасты представляют собою сложную дисперсию, в которой дисперсной фазой являются микро- и наноразмерные частицы припоя и, возможно, твёрдых компонентов флюса, а дисперсной средой являются жидкие компоненты флюса и летучие растворители.

В связи с повышением внимания общества к вопросам экологии теперь при выборе припоев более серьёзно учитывают токсичность его компонентов. В электротехнике и электронике (особенно в бытовой) всё чаще используют бессвинцовые припои.

См. также

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You usually solder a component to a pad, not directly to a trace. 90013 90037 When you need to undo solder mistakes 90038 90012 If you do make a mistake with solder, you’ll be glad to know that you can undo a bad solder. One method is to just heat up the bad solder and then suck it away with a solder sucker, a desoldering pump you can purchase. 90013 90012 Another way to remove unwanted solder is to use 90015 copper braiding 90016.You put the braiding on top of the solder that you want to remove and heat it with your soldering iron. The copper braiding absorbs the unwanted solder. You then discard the used copper braiding. 90013 90037 Ten tips for successful soldering 90038 90012 Because soldering is an important skill, you’ll want to master the basic techniques quickly. Here are some essential tips to good soldering: 90013 90064 90003 Remember the old joke about knowing which end of the soldering iron to hold on to? Seriously, a soldering iron can burn you or cause a fire.Liquid solder can cause severe burns too, so always use caution when melting solder. 90004 90067 90064 90003 When you solder something, it will remain hot for many minutes. Always grab parts with pliers to avoid getting burned even after the soldering iron is removed. 90004 90067 90064 90003 Purchase the correct solder type and width, as well as the correct soldering iron and tip. Think small tip and thin solder. 90004 90067 90064 90003 Some soldering kits include training materials to help you master the art of soldering.Although people can tell you how to solder, good soldering requires hands-on experience. Take the time to solder a few cheap test components into a test prototype board to get your technique down before using your skills on somewhat more costly electronic parts. 90004 90067 90064 90003 If your solder looks like a clump of wadded-up aluminum foil, you’ve soldered it incorrectly. The solder should look smooth and shiny and must cling to both items (for example the component pin or wire and PCB pad) to make a good connection.90004 90067 90064 90003 Incorrect soldering (such as cold solder joints) can lead to all sorts of problems that can be hard to track down. 90004 90067 90064 90003 Be careful not to apply your soldering iron for long periods of time. Otherwise, you can damage sensitive components or burn up a circuit board trace. You should solder quickly so that your components or trace do not stay hot for too long. 90004 90067 90064 90003 You should always make a mechanical connection before making a solder connection.For example, check to make sure the component pin actually touches the wall of the pad hole before you solder it. This will ensure that your soldering goes quickly and smoothly and will help to keep a solder joint from «bridging» to the pin and separating. 90004 90067 90064 90003 You may want to flux before soldering to get a cleaner solder. 90015 Flux 90016 is a pasty, greasy, oily substance that helps to clean the metallic surfaces being soldered. It also helps you produce smooth solder joints that adhere well to pin and pad surfaces.90004 90067 90064 Rosin-core solder has flux conveniently within the solder, so fluxing is usually not necessary. However, for a dirty or older solder joint, where the flux may have dissipated, you may want to brush a little flux on to help you rework the old solder joints and make them clean and smooth again. You can purchase a small can of flux at just about any electronics store. 90067 90064 90003 Only experience will tell you if you have soldered correctly, so ask an experienced soldering friend to check your work.Doing so can save you hours of debugging time later. 90004 90067 90037 Keep your soldering tools clean 90038 90012 You should perform preventative maintenance and regular cleaning to prolong your soldering iron’s life. Do not let your soldering iron tip get dirty. While your soldering iron is hot, clean the tip often with a bit of tip cleaner and a moist sponge or paper towel. Remember: A dirty soldering iron will make terrible solder joints. 90013 90012 While your soldering iron is hot, you may want to 90015 tin 90016 the tip with solder to get it shiny and clean and to remove any dross or rosin.Tinning also helps prevent oxidation. To tin the tip, get your soldering iron hot and then coat the tip with solder. Your tip should look like chrome or silver. 90013 90012 Always unplug your soldering iron when you’re finished using it to help prevent oxidizing and burning up the tip. 90013 90012 90119 About the Book Author 90120 Roger Arrick is president and founder of Arrick Robotics, a maker of PC-based motion control systems for a variety of scientific applications.Robot building is his hobby and his passion. 90013 .90000 What is Solder »Electronics Notes 90001 90002 An overview of what is solder, the types to be used for electronics soldering and how it may be used for soldering in electronic construction. 90003 90004 90005 90006 Soldering Tutorial Includes: 90007 90008 Soldering basics Manual soldering: how to solder Soldering irons Tools for soldering Solder — what it is and how to use it De-soldering — the secrets of how to do it properly Solder joints PCB solder resist 90009 90005 90006 See also: 90007 SMT soldering techniques for PCB assembly 90009 90004 90005 Although solder is widely used in the electronics industry and for connecting components and securing them in place, it is sometimes useful to ask what is solder to gain an understanding of what it is and how best to use it.90009 90017 Solder is obviously a key element in any form of electronics construction where soldering is undertaken. It provides a mechanical and electrical joint that is essential to keep components in place once a circuit has been assembled. While the mechanical strength is important, it is also necessary to ensure that the soldered joint provides a good electrical connection is made between the two connections that require joining. This can only be achieved satisfactorily if the medium, i.e.the solder joining the two conducts electricity well. 90009 90017 A further requirement of the material making the joint is that it must be easy and convenient to use. Solder has the advantage, unlike other mixtures or pure metals that it melts at a relatively low temperature. This means that it is possible to use it in the construction of electronics equipment .. 90009 90021 What is solder? 90022 90017 Traditional solder that used to be used for soldering in the electronics industry used to be a mixture of tin and lead.Different types of solder are used for different purposes. Solder is of course used in plumbing. The type of solder used for electronics usually contains 60% tin and 40% lead. This is often known as «60/40» solder. It is what is termed a «Eutectic Mixture». Although this is a chemical term, basically this type of mixture melts at a temperature well below that which might normally be expected. 90009 90017 In additional to the metal constituents flux is also required to ensure that good joints are made.Flux is an acidic mixture that helps remove oxides from the area of ​​the joint and therefore helps the solder flow easily over the joint and form a good bond. The flux can be seen as a brown liquid as a solder is heated, and it sometimes gives off a pungent smoke that can act as a irritant. This is one reason why soldering should always be carried out in a well ventilated area. 90009 90017 For plumbers solder, a separate flux is used, but for electronics solder, it is contained within the solder itself.The solder used for electronics is normally in the form of a wire, and if it is carefully cut small cores of flux can be seen running through the solder. The amount contained is correct for making electronics joints and separate flux should never be used. 90009 90021 Solder sizes 90022 90017 Solder for electronic construction is sold in the form of a thin wire. When soldering, this makes it easy to handle and apply to the place where the soldered joint is to be made. Different sizes of solder are available and a choice will have to be made when buying any.For most applications for electronics soldering, this will make little difference. The thinner wire is much better for fine work. If it is used for normal soldering then the thin solder can be slightly less convenient because longer lengths are used making a normal joint. 90009 90017 The different solders that are produced are generally specified either in Standard Wire gauge (SWG) or America Wire gauge (AWG). For most printed circuit and general soldering work choose 20 to 22 SWG solder (19 — 21 AWG), although for larger joints a thicker solder, possibly 18 SWG (16 AWG) is better.90009 90021 Lead free solder 90022 90017 With the drive to reduce the amount of lead being used for environmental and health reasons, lead free solder is now being widely used. A European Directive mandates that solder containing lead shall not be used commercially. This means that for any soldering to be undertaken by the hobbyist the traditional solder containing lead will not be available. 90009 90017 The traditional tin lead solder is being replaced by other types of lead free solder.A variety are appearing on the market. One type contains 99.3% tin, and 0.7% copper. This has a very similar melting point to tin lead solder and melts at around 227C. Another type is being sold and contains a small amount of silver. Although slightly more expensive than the tin copper solder it has a lower melting point at around 217C. This second type of solder is sometimes sold as «Lead free silver solder». However it should be remembered that it only has a small amount of silver, and there are other silver solders on the market.These solders are sold in reels or in dispensers in the same way that the traditional tin lead solder was sold. 90009 90017 In use these new lead free solders perform in a very similar fashion to that of the traditional solder. Although the melting point is slightly higher, this is not normally noticeable when used with ordinary soldering irons. There are also not believed to be any other differences in the method of use. It should therefore not present a problem to the home constructor or hobbyist.90009 90021 Summary 90022 90017 When starting to build electronic circuits it is essential to choose a solder suitable for the job, and not a type of solder used for plumbing, etc. With the new directives on the use of lead free solder, these new forms of solder are now widely available, and should obviously be used if possible. 90009 90017 When soldering, every care should be taken to ensure that the hot soldering iron can not cause injury or fire, and additionally it is necessary to ensure that soldering is undertaken in a well ventilated area so that the flux fumes are not inhaled.A general safety mindset should be used to ensure that no injury or health hazards are present, and in this way, circuits can be safely constructed and soldered. The end result can then be pride in the circuit that has been built. 90009 90017 Although solder is taken for granted in the electronics industry, it is often helpful to ask what is solder so that a greater understanding of its nature and properties can be gained so that it can be used correctly and better results obtained. 90009 90005 90006 More Construction Ideas & Concepts: 90007 90008 Soldering SMT component soldering ESD — Electro-Static Discharge PCB manufacture PCB assembly 90008 90006 90057 Return to Constructional Techniques menu.. . 90058 90007 90009.90000 What is Solder Paste & How to Use It »Electronics Notes 90001 90002 Solder paste is applied to surface mount boards prior to pick and place and when passed through an infra-red reflow machine, melts to provide the soldered joints. 90003 90004 90005 90006 SMT Soldering Includes: 90007 90008 SMT soldering techniques Wave soldering Reflow soldering Soldering BGAs What is solder paste & how to use it 90009 90005 90006 See also: 90007 Soldering basics Manual soldering: how to solder Soldering irons Tools for soldering Solder — what it is and how to use it De-soldering — the secrets of how to do it properly Solder joints 90009 90004 90005 Solder paste is the form of solder that is used in association with infrared reflow machines during the PCB assembly process.90009 90005 Solder paste is used in PCB assembly as it provides significant advantages and its form enables the process to become a simple and easy process. 90009 90005 The solder paste can be sued within large scale PCB assembly, or even within prototype production. In fact it is used in most forms of SMT assembly, proving an easy to use medium for the solder. 90009 90021 What is solder paste 90022 90005 Solder paste is a mixture of minute solder spheres held within a specialised form of solder flux.As the name indicates it has the texture of a paste, and hence the name. 90009 90005 The fact that it is a paste means that it can be easily applied to the board during PCB assembly. 90009 90005 The solder particles are a mixture of solder. Traditionally this used to be tin and lead, but with the legislation has been introduced around the world, to only use lead free solders. These may be made from a variety of mixtures. One is 99.7% tin and 0.3% copper, whereas there are other mixtures that include other metals including tin.90009 90021 Solder paste grades 90022 90005 There are various grades of solder paste and the required type can be selected to fit in with the PCB assembly process used. The solder paste is graded according to the size of the small solder balls. As they can not be exactly graded, the different types have a band of solder ball sizes between which 80% of the minute solder balls fall. 90009 90033 90034 90035 90036 90037 IPC Type Designation 90038 90037 Particle Size (μm) * 90038 90041 90035 90036 90044 Type 1 90045 90044 75 — 150 90045 90041 90036 90044 Type 2 90045 90044 45 — 75 90045 90041 90036 90044 Type 3 90045 90044 25 — 45 90045 90041 90036 90044 Type 4 90045 90044 20 — 38 90045 90041 90036 90044 Type 5 90045 90044 10 — 25 90045 90041 90036 90044 Type 6 90045 90044 5 — 15 90045 90041 90036 90044 Type 7 90045 90044 2 — 11 90045 90041 90036 90044 Type 8 90045 90044 2 — 8 90045 90041 90091 90091 90093 90094 90005 90006 * 90007 80% minimum between the stated sizes 90009 90005 Solder can also be categorised according to the type of flux used: 90009 90101 90102 90006 90104 Rosin based solder pastes: 90105 90007 Rosin based pastes are made of rosin, a natural extract from pine trees.These fluxes can be cleaned if required after the soldering process using a solvent (potentially including chlorofluorocarbons). 90107 90102 90006 90104 Water soluble flux based solder pastes: 90105 90007 Water-soluble fluxes are made up of organic materials and glycol bases. There is a wide variety of cleaning agents for these fluxes. 90107 90102 90006 90104 No clean solder paste: 90105 90007 A no-clean flux is made with resins and various levels of solid residues. No-clean pastes save not only cleaning costs, but also capital expenditures and floor space.Although the no-clean flux based solder pastes sound attractive, they need a very clean assembly environment and may need an inert reflow environment. 90107 90120 90021 Solder paste storage 90022 90005 In order to ensure that the solder paste is suitable for proving the highest performance for PCB assembly it is necessary to ensure that it maintains the required properties. To achieve this it is imperative that the solder paste is stored correctly. It should always be stored in an airtight container to prevent oxidation.The very large surface area of ​​the minute solder spheres, means that oxidation can present a very great problem. 90009 90005 Additionally, the solder must be stored at low temperatures. Not only does this reduce the rate of any oxidation there may be, but it also reduces the rate at which the flux degrades. While a low temperature is imperative, it should not be stored at a temperature below freezing. 90009 90005 In view of the way in which solder paste can degrade, it also has a defined shelf life and it should not be used after its end date.If old solder paste is used there is a distinct risk of a much higher defect rate, and the cost of any rework incurred would be well beyond the cost of replacing the solder paste. 90009 90021 How to use solder paste 90022 90005 When solder paste is used in mass PCB assembly as well as prototype PCB assembly there are a number of stages that are undertaken. First solder paste is applied to the printed circuit boards. The solder paste is only applied to the areas where solder is required. This is achieved using a solder paste stencil that only allows the solder paste through in certain areas.90009 90005 There are many ways of achieving this, but typically a stencil is placed over the board, and the paste is applied though this, ensuring that the required amount is applied — too little and the joints will have sufficient solder — too much and the joints will be too large and there may be the possibility of poor joints and even shorts between adjacent pads, etc. 90009 90005 Once the solder paste has been applied to the printed circuit board, it is then passed into the pick and place machine where the components are added.The solder paste has sufficient tension that it holds the components in place. However care should be taken not to knock the board at this stage otherwise the components may move of fall off. Additionally the board should be soldered within a few hours of being placed, otherwise the solder paste may deteriorate. 90009 90021 Purchasing solder paste 90022 90005 Solder paste can obviously be bought in industrial quantities for large PCB assembly plants, but it can also be bought in smaller qualities.It can be purchased in tubs and syringes. These are particularly useful to applications like general or BGA rework areas or for small prototype assembly. 90009 90005 Solder paste is widely used in PCB assembly — both in mass production and also for prototype PCB assembly. It provides an excellent method of applying the solder that is applicable to large and small forms of PCB assembly. 90009 90005 When used with care it enables very high quality soldered joints to be produced, however very careful control of the process is required if this is to be maintained, and any issues discovered need to be fed back into the process to correct the issue as quickly as possible.In particulart is necessary to apply the correct amount, and in the correct place. Additionally the solder paste must be used within its «use by» date to ensure that joints are of the required standard. 90009 90005 90006 More Construction Ideas & Concepts: 90007 90008 Soldering SMT component soldering ESD — Electro-Static Discharge PCB manufacture PCB assembly 90008 90006 90104 Return to Constructional Techniques menu. . . 90105 90007 90009.90000 Ultimate Guide to Electronic Soldering 90001 90002 90003 90004 What is soldering? 90005 90006 90007 90004 Soldering is the joining of two metal surfaces mechanically and electrically, with the use of metal called solder (pronounced «sodder»). Solder secures the connection so it does not break loose from vibration, other mechanical forces and provides electrical continuity, so the electronic signal travels through the connection without interruption. The solder is melted using a soldering iron.Flux is used to clean and prep the surfaces, which allows the melted solder to flow (or «wet») and bond with the metal surfaces. 90009 90005 90004 Hand soldering is the process of soldering one connection (called «solder joint») at a time, compared to more automated soldering processes in wave soldering or reflow oven equipment. 90005 90004 90009 90005 90002 90003 What do I need to solder electronics? 90006 90007 90004 When soldering an electronic connector to a contact point (often called a «pad»), you generally need the following: 90005 90022 90023 A soldering iron capable of reaching the melting point of the solder 90024 90023 Wire solder, with or without a flux core 90024 90023 Flux if wire solder does not include a flux core or if the additional flux is needed 90024 90029 90002 90003 What is a soldering iron? 90006 90007 90004 A soldering iron is a hand tool used to solder two metal surfaces together.At its simplest form, it consists of a metal tip, a heating element that brings the tip up to soldering temperature, an insulated handle to allow safe holding of the soldering iron, and a plug for either a wall outlet or the soldering station. 90005 90004 The soldering tip’s job is to transfer heat from the heating element to the work. It has a copper interior, with is an effective and efficient thermal conductor, iron plating to protect the soft, corrosive-prone copper from flux and solder, and chrome-nickel plating to keep the flux from wetting up the tip.90005 90004 Beyond that, there are options that provide better control over the soldering iron temperature and heat response (time it takes to heat up again after soldering). Some soldering tips are metal slugs that rest against the heating element, and others are integrated with the heating element in a cartridge. 90009 90009 90009 90005 90002 90003 What is the difference between a soldering iron and a soldering station? 90006 90007 90004 On the low end, most appropriate for hobbyists, a soldering iron may plug directly into the electrical wall outlet, which provides no control over soldering iron temperature.Just on or off. With a soldering station, the soldering iron plugs into the station for greater control over temperature, and other features like set-temperature memory, lock-out, etc. 90005 90002 90003 What type of solder should I use? 90006 90007 90004 While there is a large variety of different types of solder, at the most basic, you need to choose between lead or lead-free, the diameter of the wire, flux core or solid wire, and the type of flux. 90005 90022 90023 90003 Lead or lead-free 90006 — Solder is generally a combination of metals, which are chosen for the best reliability and conductivity.Lead, often combined with tin, has been the mainstay of electronic soldering since there has been electronic soldering. Lead has a relatively low melting point and readily wets and flows, which makes the process faster, easier, and more fool-proof. Because of environmental and health concerns around lead, there has been pressure to move to lead-free solder, which is often a combination of tin and silver. Lead-free solders have a higher melting point and generally require more active or more concentrated fluxes (higher solids content) to achieve the same soldering performance as leaded solders.For typical manual soldering, if done properly, reliability should be about the same. For high-end electronics used in extreme environments (e.g. aerospace electronics), there are concerns with the tendency of bright tin to crystallize and form tin whiskers, thin wires of tin that can grow from the solder joints. 90004 If you are repairing or assembling electronics for use in the US, lead solder is the easiest to work with and provides the most reliable solder joints. The lower heat also generates less thermal stress on the rest of the PCB.If the end product is being shipped outside of the US, especially to Europe, you should consider lead-free solder. An exception might be for high-reliability electronics like used in aerospace. In that case, check with the specifications and requirements of the end-user of the electronics. Lead-free may still be required, or there may be exemptions in place that allow for the use of lead solder. 90005 90024 90023 90003 Diameter of solder wire 90006 — Make sure you do not confuse solder wire intended for plumbing with electronics solder wire.Wire for plumbing will be much thicker, 2mm diameter or higher. Electronics solder wire will be thinner, 1.5mm or smaller, down to 1 / 2mm or less. Match the diameter to the size of the connectors and contacts you are soldering. Too small and you will be going through too much solder, and too large could be hard to maneuver around a dense PCB, and could increase the chance of thermally stressing or even soldering other components that are unrelated to your repair. 90024 90023 90003 Flux core or solid wire 90006 — Most wire solder comes with a flux core, so the flux automatically activates and flows over the soldering area when the solder is melted.It is more convenient and efficient to work with. Solid wire can be used, with flux added with a brush, a bottle dispenser, or a pen dispenser. Unless a very specific flux is required that is not available as a wire solder core, flux core wire solder is generally recommended. 90024 90023 90003 Type of flux 90006 — No-clean flux is a good choice for soldering where cleaning is to be avoided. The light residue can be left on the board, or removed with a flux remover. Rosin activated flux (RA) provide excellent solderability in a wide variety of applications.It is best to remove the residue after soldering for aesthetics and avoid corrosion down-the-line. Rosin flux (R) or mildly activated rosin flux (RMA) can generally be left on the PCB after soldering unless the aesthetics are a problem. Water soluble flux (OA) is a very active flux engineered to be removed easily with DI water, like in a batch or in-line system. It can also be removed with isopropyl alcohol (IPA). It is very important to clean off water soluble flux residues because they are highly corrosive.90004 You may also see options for «halogen-free» or «zero halogen». This is for companies that have green initiatives, or have to comply with halogen restrictions due to regulatory or customer restrictions. Halogens include chlorine, fluorine, iodine, bromine and astatine elements. These can come with trade-offs like cleanability, so if you are not required to eliminate halogens from your process, it is easier to stay with standard fluxes with halogens. 90005 90024 90029 90009 90002 90003 Should I use lead or lead-free solder? 90006 90007 90004 If you are repairing or assembling electronics for use in the US, lead solder is the easiest to work with and provides the most reliable solder joints.The lower heat also generates less thermal stress on the rest of the PCB. If the end product is being shipped outside of the US, especially to Europe, you should consider lead-free solder. An exception might be for high-reliability electronics like used in aerospace. In that case, check with the specifications and requirements of the end-user of the electronics. Lead-free may still be required, or there may be exemptions in place that allow for the use of lead solder. 90005 90002 What is flux? 90007 90004 Think of flux and a prepping agent for the soldering process.When joining two metal surfaces together with solder, there needs to be a good metallurgic bond, so the solder joint does not break loose or electrical continuity fluctuate with mechanical, temperature and other stresses. Flux removes any oxidization that may be present and slightly etches the surface to promote wetting. «Wetting» is the process of solder flowing over the surface of the contacts and soldering tip, which is very important in the soldering process. 90005 90002 90003 What type of flux should I use? 90006 90007 90004 No-clean flux is a good choice for soldering where cleaning is to be avoided.The light residue can be left on the board, or removed with a flux remover. Rosin activated flux (RA) provide excellent solderability in a wide variety of applications. It is best to remove the residue after soldering for aesthetics and avoid corrosion down-the-line. Rosin flux (R) or mildly activated rosin flux (RMA) can generally be left on the PCB after soldering unless the aesthetics are a problem. Water soluble flux (OA) is a very active flux engineered to be removed easily with DI water, like in a batch or in-line system.It can also be removed with isopropyl alcohol (IPA). It is very important to clean off water soluble flux residues because they are highly corrosive. 90005 90004 You may also see options for «halogen-free» or «zero halogens». This is for companies that have green initiatives, or have to comply with halogen restrictions due to regulatory or customer restrictions. Halogens include chlorine, fluorine, iodine, bromine and astatine elements. These can come with trade-offs like cleanability, so if you are not required to eliminate halogens from your process, it is easier to stay with standard fluxes with halogens.90005 90002 90003 Do I need to add extra flux when soldering? 90004 90009 90005 90006 90007 90004 If soldering a simple connection, like 2 wires, or a thru-hole lead, the flux in a flux core solder should be enough. For more complex soldering techniques, like drag soldering multiple leads on a surface mount component, additional flux may need to be added. The flux is activated and consumed when it originally flows from the core. If the solder is worked further, like when you drag across multiple leads, you run the risk of cold joints or bridging without additional flux.While more seems like it should be better, take care not to over apply flux. Excess flux needs to be removed, especially if it is not fully activated by being heated to full soldering temperature. 90005 90004 Associated products: 90005 90002 90003 How do I apply extra flux? 90006 90007 90004 Flux can be painted on with an acid brush, applied with a needle bottle dispenser, or with a pen dispenser. While more seems like it should be better, take care not to over apply flux. Excess flux needs to be removed, especially if it is not fully activated by being heated to full soldering temperature.90005 90004 Associated products: 90005 90002 90003 How do I solder? 90006 90007 90119 90023 Make sure the surfaces to be soldered are clean. 90024 90023 Turn on the soldering iron and set temperature above the melting point of your solder. 600 ° -650 ° F (316 ° -343 ° C) is a good place to start for lead-based solder and 650 ° -700 ° F (343 ° -371 ° C) for lead-free solder. 90024 90023 Hold the tip against both the lead and contact point / pad for a few seconds. The idea is to bring both up to a soldering temperature at the same time.90024 90023 Touch the solder wire to the lead and contact point / pad a few times until solder flows around the lead and contact. 90024 90023 Inspect the solder joint to make sure there is full coverage over the contact area and lead. If it is a thru-hole lead, the hole should be filled and the solder joints a slight pyramid shape. 90024 90023 If necessary, trim the lead with a shear lead cutter. Do not trim into the solder joint, which can damage the connection. 90024 90023 If using rosin activated flux, aqueous flux, or if the aesthetics of the flux residue is a problem, clean the area with a flux remover.90024 90134 90004 Associated products: 90005 90002 90003 How hot do I set the solder iron? 90006 90007 90004 600 ° -650 ° F (316 ° -343 ° C) is a good place to start for lead-based solder and 650 ° -700 ° F (343 ° -371 ° C) for lead-free solder. You want the tip hot enough to melt the solder efficiency, but excess heat can damage components as the heat travels along the leads, and it will reduce the life of the soldering tip. 90005 90002 90003 How do I tell a good solder joint from a bad one? 90006 90007 90004 Inspect the solder joint to make sure there is full coverage over the contact area and lead.Some things to watch out for: 90005 90022 90023 If it is a thru-hole lead, the hole should be filled and the solder joints a slight pyramid shape. 90024 90023 If a surface mounts solder joint, the solder should fully cover the contact pad and surround the lead. 90024 90023 The lead should not be loose or wiggle once it is soldered. 90024 90023 The solder should not overflow or bridge onto other contact points / pads. 90024 90023 If using lead-based solder, the solder joint should be shiny.Unfortunately, lead-free tends to have a duller finish, so not a good indicator in that case. 90024 90029 90002 90003 How do I select the best soldering tip for my PCB repair job? 90004 90009 90005 90006 90007 90004 The goal is to match the tip shape and size to the contact pad. That allows you to maximize the contact surface area, so you heat the lead and contact area as quickly as possible. If you choose a tip that is too large, you have more tip volume to heat, which will slow down the heat recovery, the time it takes for the tip to reheat after soldering a joint.It also runs the risk of interfering with other components and contact areas. If you choose a tip that is too small, you will not have enough surface area of ​​the tip in contact with the lead and contact area to transfer heat efficiently. It will take more dwell time, which slows you down and could increase the thermal stress of the component. 90005 90004 Make sure you are using a soldering iron and tips intended for electronic PCB soldering. Tips intended for other applications, like stained glass, plumbing, or heavy electrical work, are generally much larger than what is appropriate for electronics.90005 90004 Soldering tips come in all kinds of shapes to facilitate different PCB geometries: 90005 90022 90023 90003 Pointed or conical 90006 — The end of the soldering tip comes to either a point or around the flat area. The size is specified by the diameter of the end, so can be as small as 0.1mm or larger than 1mm. These tips are generally used when pin-point accuracy is needed, like with very fine leadless surface mount components. They may be long for greater reach in dense board design, or a shorter microtip to reduce the amount of tip metal that needs to be heated.This can improve heat recovery. The ends of the tips may also be bent to avoid interfering with other components or contact areas. 90024 90023 90003 Blade or knife 90006 — A blade tip is usually used for drag soldering when the solder is drawn across multiple contact pads. This is common when soldering surface mount technology (SMT) components. The size is measured along the length of the blade and can be 6.3mm (1/4 «) or larger. 90024 90023 90003 Chisel or screwdriver 90006 — A chisel allows you to heat a larger contact area, so useful for thru-hole solder joints.Lengths may vary and can also be bent, like with a conical tip. The size is mainly specified as the length of the flat area, but the depth or thickness of the tip may also vary. These can be so small they almost look like a point, like under 1mm, and as wide as 5 or 6mm. 90024 90023 90003 Bevel 90006 — A beveled tip has a flat oval end set at an angle. Picture a metal rod that is a cross section at an angle. The size is specified by the diameter of the «rod» or shaft and sometimes the angle of the bevel.A bevel can be as small as 1mm or 4mm or larger. 90024 90023 90003 Flow tips 90006 — A flow tip looks similar in design as a beveled tip, but instead of a flat area, it is a little indention or cup. This is also called a «mini-wave tip», and is commonly used for drag soldering, as explained above. 90024 90029 90004 Associated products: 90005 90002 Is it ok to set the heat at maximum temperature to speed up soldering? 90007 In soldering, like everything else, speed is king. Operators will turn up the soldering temperature to speed up heat throughput.This allows them to go from one solder joint to the next faster. The catch — the higher the heat, the shorter the tip life. Sure, solder stations may go up to 900 ° F, but 750 ° F is the highest you need to go for a lead-free wire. The extra heat can also unnecessarily stress components, increasing the chances of PCB failure later. 90002 90003 Why is the solder dripping off the soldering tip? 90006 90007 90004 That is an indication that the soldering tip needs to be cleaned, so it is a «cold» tip (although it is still very hot, so do not touch!).When flux and oxidation build up over time, the heat does not transfer as effectively and the solder does not wet, or flow over the tip properly. The solder will tend to melt but just drip off the tip. This makes it difficult to move to solder around contact areas the way you may need it. 90005 90002 90003 How to clean a soldering iron? 90009 90009 90006 90007 90004 Solder stations normally come with a sponge and / or brass «brillo» pad. The purpose is to remove excess flux and solder from the tip.If too much flux builds up and burns onto the soldering tip, it will eventually dewet and be unusable (but not necessarily unrecoverable). Unless the tip cleaning tools are used properly, they can do more harm than good. When choosing a sponge, make sure it is made of natural cellulose (like Plato replacement sponges). Synthetic sponges will melt onto the soldering tip and can shorten tip life. Use clean DI water. Tap water may include minerals that can build-up on the tip. When you saturate the sponge, wring it out so it is not dripping wet.Too much water can increase the thermal stress of the tip, and slow down tip recovery. 90009 90009 90005 90004 When the soldering tip has turned black from baked on fluxes and no longer wets properly, it is time for the cleaning tools of last resort. Tip tinner (Plato # TT-95) is a combination of lead-free solder and cleaner. While the soldering iron is at full temperature, roll it in the tip tinner. As you roll it, it should change from black to shiny silver as the baked flux is cleaned off.Then wipe off the excess tip tinner from the soldering tip, and retin using wire solder. Do not let the name fool you — «tip tinner» is not intended to be left on the tip. 90005 90004 Polishing bars are also available and used to scrub the tip clean of flux residues. This should only be used as a last resort because you will be removing iron along with the burnt flux. Once a tip shows pitting, actual holes in the iron, it is time to be replaced. 90005 90004 Associated products: 90005 90002 90003 Is a brass «brillo pad» or sponge better for cleaning soldering tips? 90006 90007 90004 Like everything else, there are pros and cons to each: 90005 90002 90003 Brass Tip Cleaner 90004 90005 90006 90007 90022 90023 Pro-Fast and easy to use, does not require saturating with water, and does not thermally shock the soldering tip.90024 90023 Con — It is abrasive, although brass is softer than the iron on the end of the tip. It has more of a tendency to scratch the chrome plating, which keeps the solder from wetting up the tip. That could allow corrosion to creep in under the plating, reducing the life of the tip. 90024 90029 90004 Remember to use a jabbing motion using a brass tip cleaner. Wiping across the surface increases the likelihood of flinging molten solder. 90005 90002 90003 Cellulose Sponge 90009 90009 90006 90007 90022 90023 Pro — It is an effective and fast way to clean a tip.They come with different holes or slits to make it even faster and easier, and to avoid flinging molten solder. 90024 90023 Con — Cools down the tip, so requires the tip to heat up again. It also can thermally shock the tip, especially if the sponge is overly saturated. This can shorten the tip life by creating micro-fractures in the iron plating. 90024 90029 Make sure you are using a cellulose sponge that is intended for cleaning soldering tips. Cellulose is a natural material derived from wood pulp.It will not melt and damage the soldering tip as a synthetic sponge would. The sponge should not be soaking wet, just lightly damp. Wring it out thoroughly after saturating with Deionized (DI) water. DI water is recommended to prevent mineral build-up on the soldering tip. Once your soldering tip has been cleaned, remember to retin by melting on a small amount of solder on the end of the tip. This prevents the working end of the tip, which is iron, from corroding when exposed to air over a period of time.Associated products: 90002 90003 Should I clean all the solder off the soldering tip after I’m finished soldering? 90006 90007 It is a common practice to wipe down the soldering tip before putting it back into its holder. This exposes the raw iron on the working end of the tip, which will rust in the open air. Add any residual flux to the mix, and you have a prematurely pitted soldering tip. Before taking a break or stopping for the day, wipe off residual flux and solder, and retin by applying fresh solder to the end of the tip.90002 90003 What can I do to increase soldering tip life? 90006 90007 90004 Since the move from lead to lead-free solders, a common complaint has been short tip life. The higher heat needed for lead-free solders and flux with greater activity all leads to faster tip burn-out. Often the tips turn black, and the solder beads and just drips off the end of the tip. It may also be referred to as a «cold tip», but take care not to touch it with your bare fingers! 90005 90004 Soldering tips have a copper core that transfers heat from the heating element to the working end (tip of the tip).Because copper is very soft and easily corroded and worn away, other metals are used to plate over the copper, including an outer layer of iron. Although iron is very hard, it will still corrode eventually. In addition, it can be coated with flux and other soils, which can cause dewetting. Corrosion and dewetting will slow down soldering and eventually necessitate scrapping the tip. Although all tips will have their day in the trash bin, there are several steps an operator can take to increase tip life: 90005 90119 90023 Turn down the heat 90024 90023 Properly clean the tip 90024 90023 Tin the soldering tip 90024 90023 Use special cleaning tools 90024 90134 90004 When leaving the solder station for anything over 5 minutes, turn off it off.When you leave the station turned on, the tip remains at soldering temperature, further reducing tip life. Modern soldering equipment heats up to a soldering temperature in seconds, so the time savings is not worth the reduction in tip life. 90005 90004 Associated products: 90005 90002 When should I throw away an old soldering tip? 90007 90004 When the tip is black and dewetting (solder does not cling to it), called a «cold tip», it can generally be cleaned and used again. Once there is pitting and visible corrosion, it is time for a new tip.The outside of a soldering tip is plated with iron over the thermally conductive copper center. This protects the soft, corrosion-prone copper from the harsh fluxes. Once flux gets through the iron plating through pits, the tip will be eaten away quickly. 90005 90002 90003 How can I avoid corrosion on the PCB after I’m finished soldering? 90006 90007 90004 Flux residues can cause dendritic growth and corrosion on PCB assemblies, so make sure you’re using best practices and clean the board.After all, the components have been replaced and excess solder removed … 90005 90022 90023 Clean the area thoroughly with a quality flux remover. 90024 90023 Angle the board to allow the cleaner and residues to run off. 90024 90023 If needed, use a horsehair brush or lint-free wipe to gently scrub the PCB, and then follow with a rinse. 90024 90023 If using a wipe, make sure it does not leave fibers / lint on your PCB, which may cause issues later. 90024 90029 90004 This is an optional step for no-clean flux, but still a good idea for densely populated or high voltage boards.It is absolutely required, regardless of the flux type, if you plan to follow your repair with conformal coating. 90005 90004 Associated products: 90005 90002 90007 90002 90003 10 tips to good soldering 90006 90007 90119 90023 Start with a clean surface. 90024 90023 Match the size of your wire solder to what you are soldering. 90024 90023 Match your soldering tip to what you are soldering. 90024 90023 Select your solder and flux carefully. 90024 90023 Keep your tip clean and tinned.90024 90023 Select a soldering temperature that is hot enough to efficiently melt the solder, but not too hot. 90024 90023 Hold the soldering tip to the lead and contact point / pad until both are brought up to temperature. 90024 90023 Apply enough solder to cover the contact pad and surround the lead. 90024 90023 If necessary, trim your leads with a sharp shear lead cutter, and do not trim into the solder joint. 90024 90023 Clean flux residues from the soldering area with a quality flux remover.90024 90134 90004 Associated products: 90005 .