DIP Assembly — Through-Hole Technology

Through-Hole Assembly Built for
Mechanical Strength & High Current

From automatic axial/radial insertion to wave and selective soldering — durable through-hole assembly for connectors, transformers, relays and power components that need joints stronger than SMT alone can deliver.

IPC-A-610 Class 2 / 3 Wave & Selective Soldering Hand-Solder Rework High Current-Carrying Joints
100%
Joints visually inspected
IPC 2/3
Solder joint acceptance class
3d
Standard THT lead time
99%
Joint pull-strength pass rate
600+
THT / mixed assembly projects delivered
IPC A-610
Class 2/3 solder joint standard
5d
Standard wave/selective solder lead time
100 %
Visual inspection on every joint
Industries We Serve

Where mechanical strength
can't be compromised

Wherever a joint needs to survive vibration, current or mechanical load. Hover to explore.

01

Automotive Electronics

Connectors, relays and ignition coils hand- or wave-soldered for vibration-resistant, high-reliability mechanical joints under the hood.

02

Medical Devices

Power supply connectors and terminal blocks in diagnostic equipment, built to IPC-A-610 Class 3 joint reliability standards.

03

Industrial Automation

Heavy-duty terminal blocks, transformers and contactors on control panel boards — wave and hand-soldered for years of continuous duty.

04

Consumer Electronics

Power adapters, audio jacks and connectors needing manual or automatic through-hole insertion for durable everyday handling.

05

Telecom & 5G

Power supply boards with high-current connectors for base station equipment, wave-soldered for reliable current-carrying joints.

06

Aerospace & Defense

Mission-critical connectors and relays hand-soldered to AS9100D and IPC-A-610 Class 3, with full pull-strength documentation.

07

IoT & Smart Devices

Battery connectors and antenna mounts assembled for mechanical robustness where a plug-in connection sees repeated stress.

08

Energy & Power Electronics

Transformers, inductors and high-current terminals for inverters and power converters — hand-soldered where mechanical strength is critical.

Our Process

From kitting to inspected joint —
built for strength

Through-hole joints carry mechanical load and high current that surface-mount alone can't handle. Every step below protects that reliability.

01

Kitting & Component Preparation

Leads are formed and cut to spec, components are verified against the BOM and moisture-sensitive parts are handled per J-STD-033 before they ever reach the line — preventing insertion errors and lead-related defects downstream.

BOM verification · lead forming · MSD handling
02

Automatic Axial / Radial Insertion

Automated insertion machines place axial components (resistors, diodes) and radial components (capacitors) at high speed with repeatable ±0.1mm accuracy, reserving manual insertion for components that don't fit automated tooling.

±0.1mm insertion accuracy · axial & radial · high-speed sequencing
03

Wave & Selective Soldering

Wave soldering runs controlled pot temperature and conveyor angle for consistent barrel fill across double-sided and mixed-technology boards. On dense boards where through-hole components sit near SMT parts, selective soldering targets only the intended joints — leaving reflowed components undisturbed.

controlled pot temp · selective nozzles · mixed SMT+THT
04

Trim & Form / Hand-Soldering

Leads are trimmed and formed to spec, and connectors, transformers, relays and large electrolytic capacitors are hand-soldered by J-STD-001 trained operators where extra mechanical strength or high current-carrying capacity is required.

J-STD-001 trained · connectors & transformers · mechanical strength
05

Inspection & Test

Every joint is visually inspected against IPC-A-610 acceptance criteria, with pull-strength and mechanical robustness testing sampled per lot, followed by ICT or functional test as specified by the customer.

100% visual inspection · pull-strength sampling · ICT / functional test
Equipment & Component Capabilities

Purpose-built equipment for
joints that carry load

Every insertion and soldering process runs in-house — no critical step is outsourced.

Component Insertion

Automatic Axial & Radial Insertion

Automated insertion equipment handles axial components (resistors, diodes) and radial components (capacitors) at repeatable ±0.1mm accuracy, with manual insertion reserved for connectors and non-standard parts that don't fit automated tooling.

±0.1mm insertion accuracy axial & radial leads high-speed sequencing
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Wave Soldering

Controlled Wave Solder Systems

Precision wave solder machines run controlled pot temperature profiles and conveyor angle for consistent through-hole barrel fill across double-sided and mixed-technology boards, supporting both leaded and lead-free solder alloys.

pot temp 250–265°C controlled dual-wave capability lead-free & leaded alloys
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Selective Soldering

Selective Soldering for Mixed Boards

Programmable selective soldering systems solder only targeted through-hole joints on densely populated mixed-technology boards, protecting nearby SMT components from the thermal stress a full wave pass would cause.

mini-wave / drag nozzles localized thermal profiles mixed SMT+THT boards
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Hand Soldering

Manual Assembly & Rework Stations

J-STD-001 trained operators at ESD-safe hand-solder stations assemble connectors, transformers, relays and large electrolytic capacitors that need extra mechanical strength, high current-carrying capacity, or simply don't fit an automated process.

J-STD-001 trained operators ESD-safe stations connector / transformer specialization
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Technical Specifications

Built to IPC-A-610
Class 2/3.

Every parameter below is verified against IPC-A-610 through-hole solder joint acceptance criteria. Pull-strength and mechanical robustness reports ship with every order on request.

  • 100%
    Joints visually inspected
  • IPC 2/3
    Solder joint standard
  • ±0.1mm
    Insertion accuracy
  • 99%
    Pull-strength pass rate
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ParameterDIP / THT Assembly SpecStatus
Component Lead Diameter0.4mm – 1.2mm (axial/radial)Available
Insertion Accuracy±0.1mm placement repeatabilityAvailable
Wave Solder Pot Temperature250°C – 265°C, controlled ±2°CAvailable
Selective Soldering Nozzle1.5mm – 12mm programmable nozzlesAvailable
Board Size Range50×50mm – 460×400mm (panel)Available
Board Thickness0.8mm – 3.2mmAvailable
Mixed SMT + THT SupportYes — selective soldering standardAvailable
Solder AlloyLeaded (Sn63Pb37) & lead-free (SAC305)Available
IPC Build StandardClass 2 default · Class 3 on requestAvailable
Lead Time3–5 day standard / expedited on requestAvailable
MOQNo MOQ on prototype assemblyAvailable
Quality & Compliance

Certified processes your quality team can audit.

Every through-hole joint is built and inspected against IPC-A-610 and J-STD-001 acceptance criteria, with pull-strength documentation available on request for connector, transformer and power-component assemblies.

IPC-A-610 Class 2 / 3
Through-hole & mixed assembly solder joint standard
J-STD-001
Requirements for soldered electrical/electronic assemblies
ISO 9001 : 2015
Third-party audited quality management
IATF 16949 : 2016
Automotive assembly quality system
AS9100D
Aerospace quality management
RoHS / REACH Compliant
Full material declarations available

Testing & Inspection Methods

  • 100% Visual Inspection per IPC-A-610Every through-hole joint checked
  • Solder Joint Pull-Strength TestingMechanical robustness verification, sampled per lot
  • In-Circuit Test (ICT)Open/short and component value verification
  • Flying Probe TestFixtureless — ideal for prototype and low-volume runs
  • Functional Test (FCT)Per customer test specification
  • Thermal Cycling / Vibration TestOn request for automotive & aerospace builds
  • First Article Inspection (FAI)Documented on the first production run
Case Studies

Projects we've delivered

Real DIP / through-hole assembly challenges — and how we solved them.

Industrial · Power Supplies

High-Current Terminal Block Assembly

Wave-soldered power supply board with heavy-gauge terminal blocks and transformers for an industrial control panel manufacturer.

265°C
Pot temp
100%
Inspected
0
Rework
Outcome

Consistent barrel fill across 8,000 boards with zero wave-solder related field returns; the customer eliminated their incoming solder-joint inspection step.

Automotive · Ignition & Relay

Selective Soldering on Mixed SMT + THT Board

Dense automotive relay control board combining fine-pitch SMT components with through-hole relay sockets — selective soldering avoided reflow damage to nearby SMT parts.

Sel.
Soldering
0
SMT damage
99.7%
Yield
Outcome

Zero thermal damage to adjacent SMT components across a 15,000-unit run; the selective soldering profile is now used as the customer's reference process.

Energy · Power Electronics

Hand-Soldered Transformer Assembly

Large toroidal transformers and high-current connectors hand-soldered to IPC-A-610 Class 3 on a solar micro-inverter board.

IPC 3
Build std
99%
Pull-strength
5d
Lead time
Outcome

100% pull-strength sample pass rate across 3 production lots; the customer's field return rate for solder-joint failures dropped to zero.

Why HanSphere

Why engineers trust us
with joints that carry load.

Through-hole assembly is chosen precisely because a joint needs to be stronger, or carry more current, than SMT alone can deliver. Our process is built around that requirement, not around it.

100%
Joints visually inspected

Every joint checked, not just sampled

Wave, selective and hand-soldered joints are 100% visually inspected against IPC-A-610 acceptance criteria before a board ships — sampling isn't an option when mechanical strength is the point.

IPC 3
Class 3 available

Built to the standard your industry demands

IPC-A-610 Class 2 is our baseline; Class 3 high-reliability build is available for automotive, aerospace and medical customers where every joint must survive the full product lifetime.

99%
Pull-strength pass rate

Mechanically robust, not just electrically sound

Solder joint pull-strength testing verifies that connectors, transformers and power components hold under mechanical load — not just that they pass a continuity check.

3d
Standard lead time

Fast turnaround without cutting inspection corners

Standard THT and mixed-assembly lead time is 3–5 days, with wave, selective and hand-soldering scheduled in parallel — inspection and pull-strength sampling are never skipped to hit a date.

FAQ

Frequently asked questions

Common questions about DIP / through-hole assembly, soldering methods and inspection.

Wave soldering passes the entire underside of the board through a molten solder wave, ideal for boards that are purely through-hole or have SMT components rated for the wave process. Selective soldering targets only specific through-hole joints using a programmable nozzle, which is required when THT components sit close to SMT parts that would be damaged by a full wave pass. We'll recommend the right process at DFM review based on your layout.

Yes — mixed-technology assembly is one of our most common builds. SMT components are placed and reflowed first, then through-hole components are inserted and soldered using wave or selective soldering, chosen to protect the already-reflowed SMT joints. See our dedicated SMT Assembly service for the surface-mount side of the process.

Both. Automated wave and selective soldering handle the bulk of standard through-hole joints, but connectors, transformers, relays and large electrolytic capacitors that need extra mechanical strength or don't fit automated tooling are hand-soldered by J-STD-001 trained operators at ESD-safe stations.

All through-hole joints are built and visually inspected to IPC-A-610 Class 2 as standard, with Class 3 high-reliability build available on request for automotive, aerospace and medical applications. Every order can include a J-STD-001 compliant process record.

Yes. Pull-strength and mechanical robustness testing is sampled per lot on connector and power-component joints, verifying the joint holds under load — not just that it passes an electrical continuity check. Reports are available on request.

Standard lead time for through-hole and mixed-technology assembly is 3–5 working days from confirmed BOM and Gerbers, depending on component sourcing, hand-soldering content and volume. Expedited scheduling is available on request.

Get a Quote

Start your DIP / through-hole
assembly project today.

Our through-hole assembly team will review your BOM and layout and return a full DFM report and quote within 24 working hours.

  • DFM review included with every enquiry
  • NDA signed on request — standard practice
  • IPC-A-610 Class 2/3 documentation available
  • Response within 24 working hours
  • No commitment required to get a quote
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