Ask the Experts
December 1, 2017 - Updated
November 2, 2009 - Originally Posted

Hand Soldering Alternative

We have a 9 up PCB array and solder 2 insulated wires to each PCB. Our existing hand soldering process is taking too long. We need to reduce this time consuming process. Do you have any suggestions?

R. B.

Expert Panel Responses

When considering adding wires to a PCB there are two possible paths to consider for improving the assembly process. 1) Is this a low to mid volume assembly product where-by a table top system and a single operator may be used? or 2) Is this a high volume assembly product where-by a more automated solution is required? Low~Mid volume solution Often, a table top soldering robot may be a good solution for adding wires to an existing PCB array. Through the use of a few assembly pallets and a soldering robot, a single operator can perform wire load, robot load and completed product unload functions. While the operator is loading up a new pallet the soldering robot is also working, soldering each wire to the PCB pads. This is a good use of time and guarantees a highly repeatable process for wire attach. High Volume solution If production requires an in-line process for attaching wires a Pick, Place and Solder robot may be a better fit. Typically the wires are pre-stripped and placed in such a manner that a robot can pick the wire and place it so that the striped end is located on the PCB pad. A hot iron can lower to then solder the wire into place. This type of solution is typically designed for a single process and obviously costs much more than the table top system, mainly due to the controls and vision system required. PROMATION offers a great table top soldering system if this customer is interested in this type of solution.

Gary Goldberg
President and CEO
Mr Goldberg has practical experience in production line layout, process flow and cycle rate analysis. He knows how to avoid bottle necks and most related PCB or pallet handling questions.

In order to improve output on a hand soldering project, experts recommend doing two things...

You need to make sure you are using the largest soldering tip (width and mass)possible for the job and you need to be using a soldering iron with high thermal output/performance. That will reduce the time on each joint, improving throughput from you solderers.

The best tested soldering iron for thermal performance, year after year, is any of the JBC Tools soldering stations.

You will also get an explanation of why this is the case, but the short answer is that there is a thermocouple in the tip that is connected to a microprocessor that monitors the temperature strain on that tip and responds with power from the 140 watt capable power supply.

You will get approximately 30% greater output, just by changing irons. It is smart soldering, with live, closed loop, microprocessor controlled temperature adjustment, and power supply capable of keeping up with the heaviest of heat sinks.

As a feature, it does not need to be calibrated either...Blue Thunder Technologies has great pricing on these stations, the former JBC sales manager is the Vice President (still best technical resource for this equipment in the states...) and available for support whenever needed.

Claudio Orefice
High-Tech Conversions Inc.
Claudio Orefice is president of High-Tech Conversions. They manufacture a variety of wiping products and can supply virtually any type of consumable item used in cleanrooms, assembly lines, laboratories and manufacturing

We have assemblies with wires that are located around assembly which are mixed technology. We terminate the wires with griplets, to prevent wire from moving through the hole, and then fixture the top of the board with a pallet. This prevents damage from preheaters when we wave solder the wires into the PCB. Some assemblies will not allow this, due to insulation rating, but in many cases this is a feasible option. You need to monitor/engineer your lead to hole ratio to allow this method to properly solder. Using this menthod with properly engineered system, produces more consistent solder joint and volume than hand soldering can attain.

Rodney Miller
Capital Equipment Operations Manager
Specialty Coating Systems
Rodney is currently Operations manager at SCS coatings, Global Leader in Parylene and Liquid Coating equipment. Rodney applies his BS in Computer Integrated Manufacturing from Purdue University, along with 20+ years of Electronic manufacturing and Equipment Assembly, to direct the Equipment business at SCS Coatings. "We provide unique, value added coating equipment solutions for our customers". Including conformal, spin and Parylene coating expertise.

Hand soldering is manual, time-consuming and is not capable of delivering the same solder volume from pin-to-pin. A solder preform with individual flux application / flux-coated preform could be a good option - this can be reflowed in conjunction with the solder paste. The preform could mostly be any shape - donut / rectangle / horse-shoe. Integrated Solder Preforms Data Sheet Solder Preforms

Karthik Vijay
Technical Manager - Europe
Indium Corp.
Currently with Indium Corporation and responsible for technology programs and technical support for customers in Europe. Over 15 yrs experience in SMT, Power, Thermal & Semiconductor Applications. Masters Degree in Industrial Engg, State University of New York-Binghamton.

The answer depends on why the hand soldering process takes so long. If the wire is stranded and the operators have trouble inserting the wire into a throuh-hole then a pre-tinning operation could speed assembly. If your wires are inserted in a through-hole and can survive an oven reflow cycle, then dispensing solder paste at the joint is an easy way to decreace cycle time per part. If your wires cannot go through an oven, you still have to use point to point heating to solder the joints. If your primary time loss is coordinating the insulated wires with the solder wire and iron, then solder paste can be preapplied to the joint area. This allows one hand to hold the insulated wire in place and the other apply the soldering iron. There are other possible root causes for your process to be excessively time consuming. Each has a solution if identified.

John Vivari
Application Engineering Supervisor
Nordson EFD
Mr. Vivari has more than 15 years of electronic engineering design and assembly experience. His expertise in fluid dispensing and solder paste technology assists others in identifying the most cost effective method for assembling products.

It sounds like your current soldering system is not able to keep up with your process needs. My suggestion would be to evaluate the current soldering tip profiles that are currently in use. Keep in mind that just because your operators like a particular soldering tip, that does not mean it is the best for the application. Try to select a chisel profile tip that matches the pads area as closely as possible, this will maximize the heat transfer. Your next course of action should be to evaluate a variable power or Smartheat soldering system that will provide a fixed temperature while automatically adjusting the power output to meet the demands of your soldering application.

Edward Zamborsky
Regional Sales Manager
OK International Inc.
Ed Zamborsky is a Regional Sales & Technical Support Manager for Thermaltronics, located in New York. His position requires frequent customer visits throughout North America and the Caribbean and his position encompasses not only sales but the role of trainer and master applications engineer for all of Thermaltronics products. His expertise includes such specialties as hand soldering, convection and conduction reflow techniques, array rework, fluid dispensing equipment, and fume extraction. Ed has authored many articles and has presented many papers on topics such as; Low Volume SMT Assembly, Solder Fume Extraction, SMT Rework, BGA Rework, Lead-Free Hand Soldering, High Thermal Demand Hand Soldering, Lead Free Visual Inspection and Lead Free Array Rework.

Selective Solder may work! We would be happy to evaluate this at Juki.

Bob Black
North America Sales Manager
Essegi Automation
Mr. Black was the President and Co-Founder of Zevatech in 1977 and introduced first Pick and Place System at Nepcon West 1980. Bob is now the President, CEO and Co-Founder of Juki Automation Systems. He is also a Co-Founder of the SMEMA Council of IPC. He serves as a member of SMTA and SEMI..

One product that might solve your problem is AMP-BARREL terminals offered by Tyco Electronics. The AMP-BARREL Terminal is designed to interconnect discrete wires to printed circuit boards without permanently soldering them in place by the utilization of an insulation displacement termination barrel, These insulation displacement terminals are suitable for most printed circuit boards from .047 to .125 thick and can be mounted in a free-standing manner wherever required on the PCB. The terminals can be purchased in loose piece or strip form for semiautomatic machine insertion. Upon insertion onto the PCB they can be wave soldered like any other through hole component. Termination is achieved by placing the end of a pre-cut unstripped wire horizontally to the board at the top of the AMP-BARREL Terminal. Insertion to the proper depth is accomplished by the use of a simple, lowcost screwdriver type tool or low cost plastic stuffer cap. These caps use a standard Phillips type screwdriver to terminate the wire. When left in place on the terminal they provide strain relief and insulation. AMP-BARREL Terminals accept a wide wire range, solid or stranded, within the same terminal. For example the .125 diameter AMP-BARREL Terminal accepts a wire range of 28-18 AWG with a maximum insulation diameter of .086. The product will terminate one or two wires of the same type. If your PCB can be pre-populated with wave soldered AMP-BARREL Terminals the termination of discrete wires to the assembly will be fast and easy. If you are interested in this approach I would suggest you go to the Tyco Electronics web site and look up the AMP-BARREL Terminal product within their Printed Circuit Board Terminals and Disconnects product catalog.

Peter Vigneau
Vice President
Circuit Technology Center
Mr. Vigneau has been a key member of the team at Circuit Technology Center since 2008. He has vast expertise, experience and understanding of complex circuit board rework, repair and modification operations. He is one of the most knowledgeable experts in this area across the globe.

One option could be to use a solderingiron with an auto solder wire feeder like the JBC AL. This would free up ahand.

Gerald Gardener
Sales Manager
JBC Tools Inc
With over 10 years experience in design and product development, I offer technical support to our US Sales force and liase with our Europe based R&D and manufacturing departments to continually offer the end user the best handsoldering solution possible.

Reader Comment
Eliminate the hand soldering altogether and improve product quality at the same time by designing in a disconnectable interface. A PCB header can be soldered at the same time as the other components on the PCB, removing the wires from the soldering process. A separate 2 conductor wire assembly can be attached after the PCB assembly is complete. This will speed up throughput while eliminating possible cold solder joints.
Randy Dickerson, Johnson Controls Inc., USA

Reader Comment
One solution is to not hand solder wires at all. We add solid copper conductor paths at the bare board stage to eliminate hand wiring.
Art DesMarais, Additive Circuits, Inc., USA

Reader Comment
How much time are you trying to save? What is your current process time per panel, and how much time do you believe it should take to process each panel? Several solutions posted here may cost you more to implement than the time you currently spend hand soldering. If you want to make a soldering operation like this as efficient as possible, the easiest way is to
  1. Prep all the wires (cut to length, strip and pre-tin)
  2. Enusre you have a flat, wedge shaped solder tip for maximum heat transfer
  3. Flux
  4. Keep the soldering tips cleaned and tinned at all times. 5. use board holders to keep the panel vertical for easier access to both sides 6. ensure your solderers are trained in correct soldering practices
Last and most importantly, don't expect to reduce process times below a reasonable minimum unless you're willing to spend a lot of time and money optimizing and automating the process.
Vince Burns, MC Assembly, USA

Reader Comment
Why has no one suggested the obvious? Redesign the board to eliminate the jumpers. A little up front time will save you lots of headaches trying to place and solder those wires reliably and cost effectively.
Terry S.

If this is a high volume I would immediately go to another solution for these wires - is a board redesign a solution that you consider in the future? Also SMT and/or TH connectors can take this work out of your process at a certain cost - it depends on what do you consider that is more feasible for your process and of course cost effective. Is you stay with the current design, I've seen helpful advises from equipment manufacturers so I highly recommend you to get in contact with them. Please e-mail me for more details and a plan to solve the problem.

Georgian Simion
Engineering and Operations Management
Independent Consultant
Georgian Simion is an independent consultant with 20+ years in electronics manufacturing engineering and operations.
Contact me at

Reader Comment
Perhaps the PCB may be redesigned to allow for aflux dip and then solder pot dip. This change, for us, greatly changed productqty for the better. It eliminated a three person solder team, working on onePCB at a time, to allowing two ppl to work on two different PCBs at the sametime.
Wendi Medley, Signal Dynamics Corp, USA

Submit A Comment

Comments are reviewed prior to posting. You must include your full name to have your comments posted. We will not post your email address.

Your Name

Your Company
Your E-mail

Your Country
Your Comments

Free Newsletter Subscription
Circuitnet is built for professionals who bear the responsibility of looking ahead, imagining the future, and preparing for it.

Insert Your Email Address