Contract THT/PTH assembly: through-hole PCB assembly for small and medium batches

Benefits of PTH board assembly

PTH (through-hole) is not a “second-best” solution. It’s the right choice when you need:

• high mechanical strength (connectors, interfaces, wiring, terminals)
• power handling and higher currents
• bulky components or thermally demanding parts
• reliability in harsh environments: vibration, shock, temperature swings

In other words: if your board has to operate in the field and remain stable in any context, PTH often makes the difference. At CTA Electronics we handle it every day.

How we manage a controlled THT/PTH assembly

The goal isn’t “to solder components”, but to deliver boards that are consistent batch after batch and aligned with your specifications. That’s why we follow a flow designed to catch critical points before production.

1) Technical validation

Before starting the order, we check the items that most often lead to rework or line stoppages:

• BOM and part codes (alternatives/equivalents only if agreed)
• polarity, orientation, heights and mechanical constraints
• accessibility for inspection and testing (test points, critical areas)

Output: a clear list of any points to be clarified before production.

2) PTH component insertion: repeatable placement

We manage through-hole insertion with attention to details that affect final assembly:

• polarity checks and lot identification
• height/seating control to avoid stress on pins
• accurate placement of connectors, terminals and mechanical components

3) PTH soldering: wave, selective or hand (based on the board)

Soldering depends on geometry, components and critical areas:

• Wave soldering when it’s the most efficient solution for the design
• Selective soldering for mixed boards or areas that must not go through wave
• Hand soldering for complex points, special connectors or controlled rework

The aim is a joint that meets the specification: proper wetting, no bridges and adequate hole fill.

4) Quality checks: shared criteria, consistent controls

We apply structured checks and agreed acceptance criteria, focusing on:

• critical PTH joints (connectors, power, mechanical components)
• bridges, cold joints, insufficient wetting
• orientation and polarity
• lifted or stressed components

If required, we add extra controls based on the application.

5) Testing (on request)

Depending on the order, we can support tests and checks to your specification, for example:

• electrical or functional tests (with available procedures and fixtures)
• targeted checks on critical points (power rails, connectors, main signals)
• traceability for lots and variants (useful for quality and after-sales)

If you already have a test plan, we execute it; if not, we can help you define a practical one together.