Soldering with Induction Heating

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Overview
Using Induction
Setup
Materials
Problems
Solutions

Soldering is the process of joining metals by means of alloys that melt between 350ºF-700ºF. The strength of the joint depends on the chemical composition and cleanliness of the surfaces to be joined.
Soldering produces liquid- and gas-tight joints quickly and at low cost. Most soldering applications are carried out in air, with the flux acting as a barrier to surface oxidation and interaction with the atmosphere. It is a convenient and economical way to produce joints when more complex joining machines are not available or cost-effective.

Solid state RF induction heating is very well suited for soldering applications in a production environment. Heat can be applied to specific regions of a part in a very controlled and precise manner. Induction heating is well suited for production line applications (like fiber optic ferrule assemby) because of low time-to-temperature, high levels of repeatability and non-contact, clean heating.

Induction systems typically used for soldering range from 1 to 20 kW, depending on part and process requirements.

Flux is applied first to the bonding surfaces and then heat is applied to the joint area. The temperature required is just above the melting point of the solder. The solder is allowed to flow in the joint. After reflow, the solder is allowed to cool naturally and re-solidify.

Metal: Iron, nickel, copper, lead, tin, zinc, aluminum
Solder: Generally lead and tin alloys·
Flux: Necessary to rid the surface of the metals to be joined of oxides, to promote wetting and obtain intimate contact between the solder and base metal. There are different forms of flux: corrosive, intermediate and non-corrosive. Corrosive (Acid) flux cleans the surface well and is good for copper, low carbon steel, brass and bronze soldering. However, it is difficult to clean off after the process. Intermediate fluxes contain organic compounds and decompose at soldering temperatures. They are suitable for all materials that are solderable with mild fluxes. Non-corrosive fluxes are rosin-based. They are a good choice for electronic and critical soldering applications.
Heat source: fast, precise heating is best.

Low unit strength.
Little resistance to fatigue
Limited to service temperatures below 300ºF.

Cleanliness of the joint surfaces is critical.
Both metal surfaces that are to be joined need to come to temperature at the same time.
If the temperature is too high, a strong joint cannot be created.
Instead of stick-feeding the solder, use a paste or preform solder that is placed in the joint areas before heating

utm_medium	material	docid	title	blurb	regn_link	pre-reg link	pre-link ppc	post-reg link	onClick download	onClick, View
soldering		soldering_42	Soldering a Ferrule to a Fiber Optic Cable (Hermetic Sealing)	To heat a Kovar ferrule and fiber optic cable to 297°F within 10 seconds for a soldering application, to form a hermetic seal	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_41	Soldering a fine copper wire to a connector assembly	induction heating delivered a higher quality joint, is more energy efficient than the outdated system that the client was using.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_40	Soldering a steel canister for sealing	Current hand-soldering process results in uneven, non-uniform joints and requires long production times. Induction delivers uniform, quality joints by generating heat within the end-plate and reservoir walls.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_39	Soldering Fiber Optic Cable to Fiber Ferrule with Glass Preform	Induction heating provides rapid localized heat only where needed, repeatable, consistent results with clean, controllable joints	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_38	Soldering a steel funnel to flex spout	Induction heating delivers non-contact energy-efficient heat without flame, resulting in repeatable and consistent results	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_37	Hermetically sealing a fiber optic cable in a kovar ferrule	Induction heating provides instant start up time, requiring very little power resources, pin point accuracy, a clean source of heat which is easily integrated into existing automated systems	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_36	Soldering windows to time indicator housings	Soldering soda lime glass metal edged windows to steel time indicator housings	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_35	Soldering a copper chip to a silver dipped brass RF attenuator	Induction heating provides repeatable consistent results in all three areas soldered at the same time, not individually. Faster process time, increased production and even distribution of heating	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_34	Soldering wires onto three connector tabs on a three position wall socket plug	Customer is currently using a soldering iron & individually touching each soldering point which is producing inconsistent results and quality issues.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_33	Soldering 3 copper spacers to circuit board simultaneously	Induction heating delivers precise, controlled application of heat in a repeatable, non-contact, clean heating process, enabling increased production capacity and improved energy efficiency	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_27	Soldering Electrical Flex Circuits	To heat multiple joints on flex circuit strips to 180-200°F within seven seconds for a soldering application.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_26	Soldering a Radio Antenna	To heat a coaxial antenna assembly to 600°F within 2 seconds for a soldering application. The goal to improve on an existing procedure with a soldering iron which required 10 to 15 seconds.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_25	Soldering Solar Flex Circuits	Heat multiple joints on solar flex circuit strips to 500°F (260ºC) within ten seconds for a soldering application.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_24	oldering three fuse caps simultaneously	Soldering three fuse caps simultaneously to reflow lead free solder and make a joint between the fuse cap and fuse wire guide	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_23	Soldering three brass connectors in a solar panel junction box assembly	Solder three brass connectors one at a time in a solar panel junction box without affecting the components in the junction box	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_22	Soldering a steel cover onto a nickel plated EMI filter	Soldering a nickel plated steel cover onto a nickel plated steel EMI filter housing without damaging the RF circuit	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_20	Soldering 2 copper wires to copper buss bar	Induction heating delivers reduced solder time, even distribution of heating and improved joint-to-joint consistency	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_19	Soldering an LED assembly to an aluminum spotlight housing	A multi turn pancake coil is used to heat the bottom of the aluminum spotlight housing. The LED housing was not available so this application is done with temperature sensing paint to determine the feasibility	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_18	Soldering connector to wire harness	Induction heating provides reduced production cost, faster process time, hands-free heating that involves no operator skill for manufacturing	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_17	Soldering two connectors simultaneously to gound plate	Induction heating provides non-contact heat, hands-free heating that involves no operator skill for manufacturing with even distribution of heating	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_16	Soldering fabric to kovar tip assembly	A three turn pancake coil is used to heat the tip of the cone to 300 ºF (149 ºC) in 2-3 seconds	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_15	Soldering a kovar piece with glass to a copper base for a photon light source	Induction heating provides ability to use same equipment for both assembly and repair, hands-free heating that involves no operator skill for manufacturing, and uniform control of heat from part to part	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_14	Soldering brass and copper (anesthetic medical equipment)	This process is completed in two steps that use a 3 turn helical coil. The first process is to solder the brass ring to the copper piece which takes 85 seconds...	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_13	Soldering circuit board posts with lead or lead free solder preforms	Induction heating provides hands-free heating that involves no operator skill for manufacturing, lends itself well to automation, solder controlled by preforms, no excess left on board, good solder flow without over heating the board	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_12	Soldering Brass end cap on heat exchanger	A dual four turn pancake coil is used to solder 2 brass caps per cycle. Liquid solder is squirted onto the end cap and is heated for 18 seconds at 302ºF (150ºC) to burn off the flux	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_11	Reflowing the solder of an area on a circuit board	An aluminum fixture is a large heat sink to the induction field. In order for solder alloy to wick and run the length of the overlap area, flux is applied to the solder location...	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_10	Soldering of satellite antennas	Induction heating delivers increased production rate due to speed of heating, higher quality vs. a soldering iron due to precision and repeatability and cost savings due to reduced scrap and higher quality production	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_9	Soldering wires onto connector assemblies	Compared to using a manual soldering iron, induction heating precisely applies heat to for higher quality solder joints This is ideal for integrating with an automated system. By stick- feeding the solder more aesthetically pleasing parts are produced.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_8	Soldering Co-axial Wire Assemblies	A multi-turn helical coil is used and temperature-indicating paint is applied to the joint area. The wire assembly is placed over the induction heating coil, and RF power is applied.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_7	Soldering a copper tab on a speaker ring	With an efficient coil design induction heating easily reaches the desired reflow temperature in a very short amount of time.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_6	Soldering a Stainless Steel Tube to Cylinder	Heat a.125” (3.175mm) diameter stainless steel tube to a 1” diameter cylinder 1” (25.4mm) tall for a soldering application	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_5	Soldering Steel Housing	A two-turn induction coil is used to deliver the heat energy into the steel housing. A small diameter solder wire is used to form a solder ring for the assembly process...	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_4	Soldering Cellular Phone Antenna	Soldering two brass tubes measuring 3/4" and 1/4" together for use as cellular phone antennas. The lengths of tubes range from four (4) feet to twelve (12) feet, and must be soldered along the axial side.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_3	Soldering Ice Machine Evaporator assemblies	To heat a section of 3/8" copper tubing along with a 90 degree elbow for soldering. The copper tubing is to be used in Ice Machine Evaporator Assemblies, and soldering takes place after the tubes have been placed within the assembly.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_2	Soldering Brass Bellows Assembly	To heat a brass bellows and end cap assembly to 450F for soldering within 20 seconds. Presently, a soldering iron is used to produce the joint between the bellows and cap.	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired
soldering		soldering_1	Soldering Brass Slip Ring	To heat 1 3/4", 3" and 6" diameter brass slip rings and a sheathed copper wire assembly to 360F for soldering within three (3) to six (6) seconds. Currently production is accomplished by using a soldering iron and stick feeding rosin-cored solder...	apps_able.php	soldering.php	overview_soldering_2.php	db_soldering		not needed; hard-wired