Project Overview: Custom Light Sensor Board with Strict Assembly Standards
This month, we successfully manufactured a custom 4-layer light sensor PCB for a U.S.-based customer. Although the design complexity is moderate, the assembly process requires precision and strict handling protocols—especially due to the photosensitive components involved. At our facility, we embrace challenges, and for this project, we took extra care to meet every technical requirement outlined by our client.
PCB Specifications for Light Sensor Application
| Parameter | Specification |
|---|---|
| Layer Count | 4 layers |
| Track Width/Spacing | 0.3mm |
| Pads | Oil-filled via holes |
| TG Value | 150TG |
| Vias | Both PTN & NPTH present |
| Material | KB substrate |
| Solder Mask & Silkscreen | Green mask, white silkscreen |
| PCB Class | IPC Class 2 |
| Panel Size | 65mm x 65mm (1 piece per panel) |
| X-Out PCB | Acceptable |
| HDI | Not applicable |
| Surface Finish | Lead-Free HASL (LF-HASL) |
| V-Cut | Yes |
| Test Points | Included on PCB |
| Testing | 100% Electronic Testing |
PCBA Assembly Highlights
| Feature | Description |
|---|---|
| Component Procurement | Only original brand parts allowed for high reliability |
| Smallest Component Size | 0603 package (over 5 types) |
| Max Component Height | 35mm (connector) |
| Difficult Assembly Area | X1 and X2 extend beyond layout—each PCB must be assembled individually |
| Equivalent Components | Not permitted |
| BGA Components | None |
| Handling Requirements | Sensor must not be touched during brushing; components are light-sensitive |
| LED | Not included |
| External Components | Yes |
| Component Angle | Not applicable |
Assembly Challenges and Solutions
The photosensitive sensor is the core component and is placed prominently on the front side of the PCB. These sensors are extremely fragile and must not be physically contacted during production. The brushing process—typically used for cleaning boards—had to be modified:
- PCBs were brushed at a 45-degree angle to reduce contact risk
- A non-reactive cleaning agent was used that avoids damaging the sensor
Our engineering team implemented custom handling protocols to maintain full functionality and high sensor sensitivity.
Product Application: Light-Sensitive Detection Board
This board functions as a light detection module, sensing ambient brightness levels. When brightness crosses a defined threshold, the sensor sends a signal via two custom-designed transmission connectors. The layout is streamlined, with a primary focus on accurate light sensing and stable signal transmission.
Market Positioning and Demand
This product is highly application-specific—designed for a training use case in the U.S. While the general quantity demand is not high, it serves a very clear market segment. Thanks to its niche application, the board receives stable, recurring orders from dedicated users in the professional training equipment field.
Quality Assurance and Commitment
The detailed images below showcase our soldering craftsmanship and PCB fabrication standards. We apply a ISO9001-certified quality control process throughout all manufacturing stages. For future projects involving BGA pads, we also provide X-ray inspection services to guarantee soldering quality.
Interested in customized light sensor PCBs or other sensitive module development? Contact us today for a professional consultation and project quotation!
