PCB Component Height Difference Measurement

3C05.PCB Component Height Difference Measurement: Ensuring Assembly Accuracy

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3C05.PCB Component Height Difference Measurement: Ensuring Assembly Accuracy

Aug 15, 2025

1. Importance of Height Difference Measurement in PCB Components

In PCB manufacturing, the height difference between components is a key parameter for:

Soldering quality: Excessive differences may cause poor solder joints or bridging.
Automated assembly: Pick-and-place machines rely on accurate height data for proper placement.
Reliability: Uneven heights can lead to mechanical stress, affecting long-term durability.
Inspection efficiency: Early detection of inconsistencies reduces rework and scrap rates.

2. Common Height Measurement Methods

Measurement Method	Principle	Advantages	Limitations
Contact-type probe	Physical tip touches component surface	Simple and low cost	Slow, possible contact damage, unsuitable for small parts
Laser triangulation	Calculates distance from reflected laser angle	Fast, non-contact, adaptable to various surfaces	Performance affected by highly reflective or transparent materials
White-light interferometry	Measures height via interference fringes	High resolution	Sensitive to vibration, limited range
Vision-based system	Uses camera and image processing	Can capture multiple points at once	Lower vertical resolution, lighting-dependent

3. Principle and Process of Laser Triangulation Measurement

Laser triangulation displacement sensors operate by:

Step 1: Emitting a laser beam onto the target surface.
Step 2: The reflected light is received by a position-sensitive detector (PSD) or CMOS sensor.
Step 3: Based on the reflection point's position on the detector, the system calculates the precise distance.

Why it’s suitable for PCB component height difference measurement:

Non-contact, minimizing risk of damaging components.
Capable of measuring small height differences quickly.
High sampling rates allow use in fast-moving inspection lines.

4. TronSight’s Solution

The TronSight TS-P Series Laser Triangulation Displacement Sensor provides:

Sampling rate up to 160kHz for high-speed inline measurements.
±0.02% of F.S. linear accuracy and 0.02μm repeatability for precise height difference detection.
Measurement range 2~2000mm, suitable for different PCB sizes.
Supports customization in laser line width, light source, wavelength, and structural dimensions.
Built-in controller for easy system integration.

Application example:
On a PCB inspection station, the TS-P sensor measures the height difference between specific component leads and the PCB surface. This data can be used in inspection reports or to confirm compliance with assembly tolerances.