Overview of the Project
In late May, we established contact with a new customer from Russia, launching a collaborative journey that has successfully led to the development of two customized PCB assembly (PCBA) projects: one for a Computer Main Board and another for an Audio Driver Board. After resolving multiple challenges—such as electronic components replacement, international logistics to Russia, and NDA signing—we moved forward into prototype production.
The initial order includes 50 pieces of main PCBs and 150 pieces of audio driver PCBs. Upon completion of prototype testing, we will proceed to the mass production stage.
Computer Main Board PCB Specifications
- Layer Count: 4 layers
- Material: TG130
- Board Thickness: 1.6mm
- Copper Thickness: 1/0.5/0.5/1oz
- Surface Finish: HASL (Hot Air Solder Leveling)
- Solder Mask Color: Green
- Silkscreen: White
- Board Dimensions: 154mm × 125.65mm
- Panel Format: 168mm × 251.3mm, 2 boards per panel with V-cut
- Standards: Fabricated to IPC-6012 Class 2, UL-certified
- Tolerance:
- Punch tooling hole registration: ±0.005″
- Conductor width: ±20%
Since we handle in-house PCB assembly, we support X-out panels to help our customers reduce production costs without compromising quality.
Audio Driver PCB Specifications
- Layer Count: 2 layers
- Material: TG130–140
- Board Thickness: 1.0mm
- Copper Thickness: 1oz
- Surface Finish: HASL
- Solder Mask Color: Green
- Silkscreen: White
BOM Adjustment and Component Requirements
After our first quotation, the customer updated the BOM by removing components like C1, C2, HL2, HL4, and FBA, and adding a 2-pin connector. Although the customer permits the use of substitute components, the connectors require strict matching to the specifications since they directly connect to the customer’s device.
Additionally, the relay must strictly comply with the BOM parameters to ensure compatibility with their existing system. The customer requested 1% tolerance resistors instead of the standard 5% to enhance overall device precision. We updated the BOM accordingly. This adjustment slightly increased the overall cost, but we always prioritize meeting customer requirements.
- Main Board PCBA: Single-sided mounting, 25+ component types
- Audio Driver PCBA: Double-sided mounting, 14+ component types
PCBA Functional Testing Process
Before delivery, all PCBA boards undergo a functional test using a Linux system with ALSA and USB 2.0 support. Since most Chinese systems default to Windows, we specifically installed Linux to ensure compatibility with the customer’s test environment.
USB Connection Instructions
- Power: VCC/GND connected via the top-left connector labeled +5V/GND
- Data: DP/DM connected via bottom-right pins
Expected Test Behavior
- Upon USB connection:
- PL-G1 green LED remains on for 6–9 minutes (ON-STATE)
- The system should detect the Terminus 2.1 Hub in the USB device list
- Voltage probe should read approximately +5V
- After ON-STATE, PL-G1 turns off and PL-R1 red LED turns on (OFF-STATE)
- Relay switching sound should be audible
Occasional EMI errors may occur when connecting/disconnecting the CM118B Mainboard. These errors are not critical; the system should automatically reconnect and resume normal function.
For the audio driver board, once connected:
- It should appear in
lsusbas a C-Media USB Audio Device arecord -lshould detect a new recording device
Shipment and Packaging
We will notify the customer 8–10 days in advance before shipping. Each PCBA is securely packed with anti-static foam, then boxed in cartons for safe international transit.
Why Choose Us for Your PCB Assembly Projects?
This successful first-time cooperation marks a promising start to a long-term partnership. With our in-house SMT assembly, strict BOM compliance, flexible handling of prototype and volume orders, and experience in handling complex testing environments, we ensure our partners receive reliable and cost-effective PCB manufacturing services.
If you’re looking for a trusted PCBA manufacturer for your custom mainboard, audio device, or other electronic circuit board projects, don’t hesitate to reach out. Let’s build high-quality boards together.
Contact us today for a quote or to discuss your project requirements. Our expert team is ready to assist you!
