Drawn Wire Solderless Press-Fit Pins vs. Soldered Pins: Choosing the Right PCB Termination
Key Takeaways
Drawn wire pins are formed from continuous wire to create low-cost soldered or solderless press-fit terminal connections to a PCB.
The soldered or solderless press-fit terminations gives engineers the flexibility to select the connection method that best fits the PCB design, production process, cost structure, and reliability requirements.
Autosplice compliant solderless press-fit pins contain a pair of simply supported contact beams, with a thin-walled membrane between them, that flex during insertion into a plated-through-hole (PTH), generating sustained normal force against the hole wall to create a gas-tight electrical connection without the use of solder.
Compared with earlier solid solderless press-fit designs, solderless compliant pins reduce insertion stress on PCB plated-through holes, causing less damage while maintaining the retention force required for high-reliability applications.
Soldered pins, on the other hand, remain a practical solution for many established PCB assembly processes, particularly where soldering equipment, board designs, and qualification requirements are already optimized around the technology.
Solderless press-fit technology is an environmentally friendly solderless technology that can eliminate a secondary soldering operation, avoid solder-related defects, reduce thermal stress at the termination, and can complete the electrical and mechanical connection during automated insertion.
The right choice should be based on PCB design, hole tolerances, production volume, automation strategy, environmental conditions, reliability requirements, overall performance, and total applied cost rather than terminal price alone.
Understanding What Is Being Compared
The comparison between solderless press-fit pins vs. soldered pins begins with an important distinction: drawn wire, solderless press-fit, and soldered are not three competing categories of PCB pins.
Drawn wire describes the manufacturing method. Solderless press-fit and soldered describe the PCB termination method.
Drawn wire pins are manufactured from continuous wire stock and formed into precise terminal geometries for use in printed circuit boards, connectors, headers, and other electrical components. Autosplice drawn wire pins are supplied end-to-end on continuous reels to support automated insertion in high-volume PCB assembly.
The pin itself can then be engineered for different types of PCB connections. A drawn wire pin may incorporate mechanical features, such as a star or a knurl, designed to stabilize the terminal before soldering, or it may use a solderless compliant press-fit section that creates the finished electrical connection during insertion.
For engineers evaluating the two approaches, the more useful comparison is therefore:
Soldered drawn wire PCB pins
Solderless compliant press-fit drawn wire PCB pins
Both can provide reliable electrical and mechanical performance. The difference lies in how the connection is created, how the PCB must be designed, and how the termination fits into the overall manufacturing process, with implications for the assembly’s overall performance and service strategy.
How Soldered Drawn Wire PCB Pins Work
A drawn wire soldered pin is mechanically inserted into a PCB plated-through-hole and then joined by a melted metal alloy that bonds the pin to the hole wall; in through-hole processes, the lead typically extends through the board and is soldered on the opposite side. Depending on the board and production requirements, this may be accomplished via through-hole technology, such as wave soldering, or SMT technology, such as reflow of stenciled solder paste, or another compatible process. Selective soldering can be employed for mixed assemblies containing SMT and through-hole components.
The solder joint forms a permanent electrical interface between the pin and the plated-through-hole. Mechanical features on the pin, such as stars and knurls, can provide stability before soldering and can improve retention during handling and assembly.
Autosplice drawn wire pin technology includes configurations designed specifically for these applications.
Drawn Wire Solid Interference Fit Pins
Drawn wire solid interference fit pins use a rigid geometry that engages the PCB plated-through-hole during insertion. These pins incorporate star features, knurl features, coined features or other formed sections to control insertion characteristics and mechanical retention.
Autosplice pins with star features contain defined corners or contact features that interface with the plated-through-holes of standard PCB's to provide mechanical retention before and during soldering.
Autosplice Pins with knurl features contain defined bumps that interface with the plated-through-hole of thinner PCB's or with plastic substrates, while causing minimum upset or deformation of material upon insertion. Drawn wire pins with knurl features can improve anchoring in a PCB or plastic housing. Depending on the application, the pin can be positioned to support downstream surface mount technology or soldering processes while maintaining the mechanical stability required during assembly.
These designs can be useful where a mechanically stable terminal is required before the soldering operation and where the PCB hole tolerances are compatible with the pin geometry.
Soldered pin technology remains widely applicable because many PCB manufacturing lines already include established soldering equipment and process controls. Where the board design, equipment, and qualification process are optimized around soldered connections, changing the termination method may provide little practical advantage.
How Compliant Press-Fit Pins Create a Solderless Connection
Drawn wire solid pins do not flex in the same way as compliant pins, since they do not possess contact beams. Thus, for drawn wire solid pins, the relationship between the pin dimensions and PCB hole is particularly important. Excessive interference can increase insertion force and place additional mechanical stress on the plated-through-hole and surrounding PCB material. This failure mode is avoided with drawn wire press-fit pins.
A compliant press-fit pin creates its electrical and mechanical connection without soldering.
The press-fit section is engineered to be slightly larger than the finished plated-through-hole. When the pin is inserted, the compliant portion flexes inward. This controlled deformation generates normal force against the plated-through-hole of the PCB, with proper installation helping achieve the intended connection. By judicious selection of materials with low stress relaxation properties, the normal force can be maintained indefinitely within prescribed temperature limits.
The result is a mechanically secure, low-resistance interface that remains under compression after insertion.
The interface is often described as a gas-tight connection because the consistent normal force limits exposure of the interface to oxygen and contaminants. At localized contact points, the mechanical interaction between mating surfaces can also produce cold welding, especially in tin plated PTH's, that contributes to a stable electrical connection.
Unlike a solder joint, which depends on the cohesive and adhesive strength of the solder, the press-fit connection depends on controlled elastic and plastic deformation of the press-fit contact beams.
Autosplice solderless drawn wire compliant pin designs include technologies such as Barbell and Conforming Fit configurations.
Drawn Wire Press-Fit Pins vs. Soldered Pins: A Side-by-Side Comparison
The two technologies can both be suitable for high-reliability PCB applications, but they influence the assembly process in different ways.
Consideration | Soldered Drawn Wire Pins | Compliant Drawn Wire Press-Fit Pins |
Electrical connection | Created by solder joint | Created mechanically through compliant contact with PTH |
PCB attachment process | Machine or manual insertion | Machine or manual insertion |
Secondary soldering step | Typically required | Not required |
Automated pin insertion | Yes | Yes |
Continuous reel processing | Yes | Yes |
Gas-tight solderless connection | No | Yes |
Thermal processing at termination | Required | Eliminated |
Exposure to solder defects | Present | Eliminated |
Flux residue at termination | Possible | Eliminated |
PCB hole control | Important | Critical to compliant-zone performance; correct compliant-zone specification is needed for reliable results |
Rework | Typically requires solder removal | Can often be easily repaired or replaced using appropriate tooling |
Established solder-based manufacturing | Strong fit | May require process change |
High-volume automated production | Strong fit | Particularly attractive where secondary soldering can be eliminated |
Neither technology is universally superior. The most appropriate termination depends on the PCB, the electrical and mechanical requirements, the existing manufacturing process, and the economics of the complete assembly.
PCB Plated-through-hole Design and Tolerance Requirements
PCB plated-through-holes are fundamental to both soldered and press-fit connections.
For compliant press-fit technology, the relationship between the pin geometry and the finished hole diameter is especially important because the PCB hole is an active part of the electrical and mechanical connection.
A properly designed press-fit system must account for:
Finished PCB hole diameter
Hole tolerance
Copper barrel thickness
Surface finish
PCB thickness
Terminal dimensions
Compliant-zone geometry
Material strength and spring properties
If the PCB hole is too small, insertion force can increase and place unnecessary stress on the copper barrel or terminal. If the hole is too large, the press-fit connection may not generate the required normal force or retention force.
For example, the Autosplice 0.4 mm eye-of-the-needle press-fit terminal is optimized for the industry-standard 0.60 ± 0.05 mm finished PTH. Larger Autosplice EON terminals use correspondingly larger specified PTH ranges.
These dimensional relationships should always be evaluated for the specific terminal rather than assuming one standard PCB hole size applies to all press-fit pins. Proper coordination of the PCB hole and compliant zone is what delivers reliable results.
Compliant pin geometry provides more ability to accommodate dimensional variation than rigid solid pins, but that does not eliminate the need for precise control of PCB fabrication.
How the Manufacturing Process Changes
Both soldered and compliant press-fit drawn wire pins can be supplied in continuous-reel formats and inserted with automated equipment.
The difference appears after the pin enters the board.
A typical soldered assembly process is: Reel-fed pin → automated insertion → soldering → inspection or cleaning as required → electrical verification
A typical compliant press-fit process is: Reel-fed pin → automated insertion and termination → verification
That difference can become significant in high-volume manufacturing.
With a soldered pin, automated insertion places the component, but the electrical connection is not complete until the soldering process takes place.
With a compliant press-fit pin, the insertion operation itself creates both the mechanical and electrical connection, completing installation and termination in one step.
This can eliminate assembly steps associated specifically with the terminal, including wave or selective soldering, solder consumables, flux handling, and inspection for solder-related defects.
The practical value depends on the production line. If soldering is already required for other electrical components and the pin can move through the same optimized process with little added complexity, the advantage may be limited.
However, if a connector or group of pins requires a separate secondary soldering process, eliminating that operation can materially affect manufacturing efficiency.
Press-Fit Technology and Solder-Related Defects
Soldering is a mature and proven connection technology, but the final solder joint is influenced by the manufacturing process.
Potential failure mechanisms can include:
Cold solder joints
Insufficient solder
Solder bridging
Voids
Flux residue or contamination
Inconsistent wetting
Thermal damage
Fatigue during long-term thermal cycling or vibration
Automated soldering processes can control these variables effectively, but they remain variables that must be managed.
A compliant press-fit connection eliminates the solder joint entirely at that termination.
There is therefore no cold solder joint, solder bridge, or solder-related flux residue to evaluate at the press-fit interface. Connection quality instead depends on the dimensional and mechanical parameters governing the terminal and plated-through-hole.
Autosplice press-fit technology has demonstrated stable low contact resistance in high-reliability applications, and the company's existing technical material cites industry data indicating that properly designed press-fit systems can deliver a lower failure rate than soldered PCB connector terminations because they eliminate solder-related variables.
This does not mean soldered connections are inherently unreliable. It reflects the fact that compliant press-fit technology removes a number of solder-process variables from the completed connection.
Thermal Stress and PCB Assembly
Soldering requires heat.
In modern lead-free PCB assembly, processing temperatures can be significant, particularly when large connectors, high-mass terminals, or thick printed circuit boards require additional thermal energy to create acceptable solder joints.
Press-fit termination occurs mechanically and therefore avoids thermal stress from soldering at the connector or pin location.
This can be particularly useful when:
Heat-sensitive components are already mounted nearby
The board has undergone surface mount technology processing
A connector would otherwise require selective or secondary soldering
The PCB has a high copper content or significant thermal mass
Additional thermal cycles are undesirable
Press-fit does not make the complete PCB assembly solder-free. Surface mount components and other connections may still rely on soldering. The benefit is that the press-fit termination itself does not require another thermal process.
High-Layer-Count and Thick Printed Circuit Boards
As printed circuit boards become thicker or incorporate more copper and additional layers, through-hole soldering can become more challenging.
Greater thermal mass can make it more difficult to achieve consistent heating throughout the plated-through-hole without exposing surrounding components or PCB materials to additional temperature.
Press-fit technology provides an alternative because the connection is formed mechanically rather than through solder flow.
This can make compliant press-fit technology attractive for certain multilayer control boards, automotive electronics, industrial systems, and power modules where PCB construction complicates conventional soldering.
The specific board stack-up, PTH geometry, and mechanical requirements must still be validated for the selected terminal.
Reliability Under Vibration, Shock, and Thermal Cycling
Automotive, industrial, transportation, medical, and other high-reliability electronics can be exposed to significant environmental factors over their service life.
These may include:
Vibration
Mechanical shock
High temperatures
Low temperatures
Repeated thermal cycling
Humidity
Harsh conditions
Any electrical connection used in these environments must maintain both mechanical strength and electrical continuity.
A compliant press-fit connection maintains normal contact force as the pin, copper barrel, and surrounding PCB expand and contract during temperature changes. The compliant section functions as a spring, allowing the interface to accommodate dimensional movement while maintaining contact.
This characteristic is one reason compliant press-fit connectors are widely used in harsh environment applications, including automotive control modules, industrial electronics, transportation systems, and power electronics.
Soldered connections can also perform reliably under vibration and thermal cycling when the joint, board support, and terminal geometry are properly designed. The difference is that soldered systems depend on the long-term mechanical integrity of the solder joint, while press-fit systems depend on maintained mechanical contact force within the PCB hole.
For larger connectors, additional mechanical support such as housings, retention features, or mounting screws may also be used to keep external mating forces from being transferred directly into the PCB terminations.
Automation and Continuous-Reel Processing
Automation is a major advantage of drawn wire pin technology regardless of the final termination method.
Autosplice produces drawn wire PCB pins in a continuous end-to-end reel format. This allows the components to feed directly into insertion machines without loose-piece sorting or manual orientation.
The same basic component technology can support:
Semi-automatic insertion equipment
Stand-alone insertion cells
High-speed in-line insertion machines
Existing or dedicated PCB assembly processes
Continuous reel processing improves orientation consistency, reduces component handling, and supports repeatable high-volume insertion.
For compliant press-fit pins, automation provides an additional benefit: insertion can also complete the termination.
Specialized equipment can control the insertion process and, where required, monitor force and displacement to confirm that the terminal is entering the PCB hole within the expected process window.
This creates a highly repeatable process while eliminating many of the downstream operations associated with soldered terminals.
Total Applied Cost: More Than the Price of the Pin
A comparison of press-fit pins vs. soldered pins should not stop at component price.
The terminal represents only one part of the manufacturing cost.
Total applied cost can include:
Terminal cost
PCB fabrication requirements
Component packaging
Feeding and insertion equipment
Tooling
Soldering equipment
Solder and flux
Labor
Inspection
Cleaning
Floor space
Rework
Scrap
Throughput
Quality-related costs
A soldered pin may be very cost effective when the manufacturer already has an efficient, highly utilized soldering process that accommodates the terminal without additional equipment or handling.
Press-fit can become particularly cost effective when it eliminates a dedicated secondary soldering operation or simplifies the flow of the PCB through production.
For that reason, engineers and manufacturing teams should evaluate the complete assembly process rather than comparing the purchase price of individual pins.
Rework and Repair
Press-fit technology can also simplify certain rework operations.
A compliant press-fit terminal can often be removed using appropriate extraction tooling without the solder-removal processes required for a soldered connection. Depending on the terminal and PCB design, a replacement component can often be inserted into the board, making the termination more easily repaired in some production and service environments.
This can make press-fit connections easier to repair in some production and service environments.
Reworkability is not unlimited, however. Repeated insertion and extraction can affect the plated-through-hole, and acceptable rework limits depend on the specific terminal, PCB construction, and qualification requirements.
Any rework procedure should therefore be validated as part of the complete application.
When Soldered Drawn Wire Pins May Be the Better Choice
Press-fit provides significant manufacturing advantages, but soldered pins remain the appropriate solution for many PCB designs.
A soldered drawn wire pin may make more sense when:
The production line already includes an efficient soldering process
The existing PCB is fully designed and qualified around soldered connections
Production volume does not justify changing equipment or tooling
Legacy requirements specify a soldered interface
The substrate or application is better suited to a soldered termination
Redesign and qualification costs would exceed the expected manufacturing benefit
The terminal can pass through an existing solder operation without creating a separate manufacturing step
The objective should not be to replace solder simply because press-fit technology is available. The engineering question is whether changing the termination improves the complete product and manufacturing process.
When Compliant Press-Fit Pins Become Particularly Attractive
Compliant press-fit deserves closer consideration when the manufacturing strategy places a premium on automation, process simplification, and high reliability.
Common reasons to evaluate press-fit include:
Eliminating selective or secondary soldering operations
Completing the electrical connection during automated insertion
Avoiding thermal stress at the terminal location
Removing solder-related process variables
Supporting lead-free PCB assembly, which can also support more environmentally friendly manufacturing at the terminal level
Reducing assembly steps
Improving repeatability in high-volume manufacturing
Simplifying terminal-level rework
Supporting harsh automotive and industrial environments
Reducing total applied cost by eliminating downstream operations
The advantages become more meaningful as production volume increases because reductions in process time, equipment usage, handling, inspection, and rework can accumulate across large numbers of assemblies.
Choosing Between Press-Fit and Soldered Pins
Engineers evaluating the two technologies should consider the electrical connection as part of the complete PCB and manufacturing system.
Important questions include:
What PCB material, thickness, and layer count will be used?
What is the finished plated-through-hole diameter and tolerance?
What copper plating thickness can the PCB fabricator reliably maintain?
What current and voltage must the pin carry?
What retention force is required?
What insertion force can the PCB and assembly process tolerate?
Will the product experience vibration, shock, or significant thermal cycling?
Is soldering already required elsewhere in the production process?
Would the connector require an additional selective or wave soldering operation?
What production volume is expected?
How automated is the PCB assembly line?
Is repair or replacement of the connection important?
What automotive, industrial, medical, or other qualification requirements apply?
What is the total applied cost of each manufacturing approach?
Answering these questions early allows the PCB hole, terminal geometry, materials, plating, tooling, and insertion process to be developed as a coordinated system.
Autosplice Drawn Wire and Press-Fit Solutions
Autosplice combines drawn wire pin manufacturing, press-fit technology, connector engineering, and automated insertion equipment to support both soldered and solderless PCB applications.
Drawn wire pins are available in a large selection of sizes, lengths, cross sections, materials, plating systems, and retention configurations. Existing technologies include solid interference fit pins (knurl pins, star pins, coined pins), compliant Barbell designs, Conforming Fit pins, and other application-specific configurations.
Components are supplied in continuous-reel formats designed for automated processing, allowing manufacturers to move from prototype or lower-volume insertion to higher-speed production while maintaining a consistent component strategy.
For applications that require a custom solution, Autosplice engineering can evaluate the PCB, terminal geometry, connection requirements, manufacturing process, and automation together.
The objective is not simply to choose a pin. It is to develop an interconnect and assembly process that delivers reliable performance, repeatable manufacturing, and an appropriate total applied cost.
Frequently Asked Questions
Are drawn wire pins always soldered?
No. Drawn wire refers to the way the terminal is manufactured. A drawn wire pin can be designed for a soldered connection or can incorporate a compliant section that creates a solderless press-fit connection.
What is the main difference between press-fit pins and soldered pins?
A soldered PCB pin relies on a solder joint to create the permanent electrical interface with the plated-through-hole. A compliant press-fit pin creates the connection mechanically through controlled deformation and sustained normal force against the PTH wall.
Do compliant press-fit pins damage the PCB?
A properly engineered compliant pin is designed to reduce PCB stress compared with rigid solid press-fit pins, and when the hole is properly specified, compliant designs generally cause less damage during insertion. The compliant section flexes during insertion, allowing the terminal to accommodate the PCB hole while maintaining the contact and retention force needed after insertion. Correct PCB hole dimensions and plating remain essential.
Are press-fit connections gas-tight?
Properly designed compliant press-fit terminals create a gas-tight interface between the terminal and plated-through-hole. Maintained contact pressure helps protect the electrical interface from oxidation and contamination.
Does press-fit eliminate soldering from the entire PCB assembly?
No. Press-fit eliminates soldering at the press-fit termination. Other components mounted on the board may still use conventional surface mount technology, through-hole soldering, or other assembly processes.
Are press-fit pins suitable for harsh environments?
Yes. Compliant press-fit technology is widely used in high-reliability automotive, industrial, transportation, medical, and other electronics where connections may experience vibration, shock, high temperatures, thermal cycling, and other harsh conditions. The specific terminal and PCB system must be designed and qualified for the application.
Can press-fit connections be repaired?
Press-fit terminals can often be extracted and replaced, making some connections easily repaired with appropriate specialized equipment. The acceptable number of rework cycles depends on the PCB plated-through-hole, terminal design, and qualification requirements.
Are press-fit pins more reliable than soldered pins?
Both technologies can deliver highly reliable connections when properly designed and manufactured, and industry data cited for properly designed systems points to a lower failure rate for press-fit in some applications. Press-fit removes solder-related failure mechanisms such as cold solder joints, solder bridging, and flux contamination, while its reliability depends on correct terminal geometry, PCB hole dimensions, materials, normal force, retention force, and insertion control.
Can an existing soldered PCB design be converted to press-fit?
Potentially. The PCB hole diameter, copper plating, board thickness, terminal dimensions, available insertion equipment, and mechanical requirements must all be evaluated. Conversion should be treated as a PCB and manufacturing-process change rather than a simple pin substitution.
How do I determine whether press-fit will reduce production cost?
Compare total applied cost rather than terminal price alone. Consider insertion, soldering equipment, tooling, consumables, labor, inspection, rework, scrap, throughput, and the number of assembly steps required. In high-volume applications, eliminating a secondary soldering operation can significantly change the overall process economics.
Evaluate the Connection as Part of the Complete Manufacturing Process
Choosing between soldered drawn wire pins and compliant press-fit pins requires more than comparing two electrical components.
PCB construction, plated-through-hole dimensions, environmental conditions, production volume, existing equipment, automation requirements, reliability targets, and total applied cost all influence the correct choice.
Soldered pins remain a proven solution where the manufacturing process and board architecture are already optimized around soldering. Compliant press-fit technology becomes particularly compelling where manufacturers can eliminate secondary soldering, reduce thermal processing, simplify assembly, and create the finished electrical connection during automated insertion.
Autosplice can support that evaluation from the terminal through the manufacturing process, helping engineering and production teams select a drawn wire pin, press-fit termination, and insertion strategy that improves manufacturability and overall performance for the application.
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