5 Smart Questions to Verify the Circuit Board Material Your Chinese PCB Supplier Really Uses

When sourcing printed circuit boards (PCBs) from Chinese suppliers, verification of the circuit board material is crucial. Many PCB failures can be traced back to the use of inferior or incorrect materials—a problem that often goes unnoticed until it’s too late.

With so many suppliers offering a wide range of material options, how do you know if you’re getting what you paid for? The answer lies in asking the right questions.

Here are 5 smart questions to ask your Chinese PCB supplier to verify the circuit board material they are using, ensuring you get the quality and reliability your products deserve.

1. Can you provide the original COC (Certificate of Conformity) from the circuit board material supplier?

One of the most important steps in verifying the circuit board material is to check the Certificate of Conformity (COC) from the original material supplier. This document confirms that the materials have met the required industry standards and specifications, such as RoHS compliance or UL certification.

Why does this matter?

A legitimate supplier will be able to provide this certificate, showing that the circuit board material used in your PCB comes from a certified source. However, be cautious: some suppliers might offer “self-created” COCs that aren’t backed by the original manufacturer.

What should you ask?

• Ask for a COC that includes the material’s batch number, supplier details, and certifications.
• Make sure the COC is directly from the material supplier, not just from the PCB manufacturer.

2. Do you allow traceability of the circuit board material back to the original supplier batch?

Traceability of the circuit board material is another key indicator of a supplier’s transparency and reliability. A supplier that is serious about quality control will be able to trace the materials used in your PCB back to the original batch from the material supplier.

Why is this important?

Traceability of the circuit board material allows you to know exactly where the materials came from and ensures that there are no unexpected substitutions or compromises made in the manufacturing process. If a supplier cannot trace their materials, this could indicate weak internal controls or a lack of proper sourcing practices.

What should you ask?

• Request to see how the materials are tracked in their system.
• Check if they use an ERP (Enterprise Resource Planning) system or barcode labels to manage material batches.

3. Can I see a video or photo of your incoming inspection process for circuit board material?

Quality of the circuit board material starts with material inspection. Asking to see a video or photos of the supplier’s incoming material inspection process is a great way to verify that they are properly handling and inspecting materials before they are used in production.

Why is this significant?

An effective incoming inspection process for circuit board material ensures that only high-quality materials make it into the production line. It can also identify any inconsistencies in material quality early, preventing defects down the road.

What should you ask?

• Ask for a video or photos that show the actual inspection process, such as checking material thickness, labels, and visual defects.
• Ensure the inspection includes standard procedures like checking for material lot numbers and ensuring compliance with specifications.

4. Which brands of circuit board base materials do you stock regularly? Can I choose the brand?

Not all circuit board material is created equal. Some suppliers use cheaper, lower-quality base materials that can compromise the overall performance of the PCB. Reputable suppliers usually stock well-known and trusted material brands like Shengyi, ITEQ, Rogers, or KB.

Why is this crucial?

The brand of the circuit board material plays a significant role in the PCB’s durability, performance, and overall quality. High-end materials from trusted brands offer better consistency, reliability, and long-term performance. If a supplier is unwilling to disclose their material brands or offers no choice in the matter, this could be a red flag.

What should you ask?

• Ask your supplier for a list of circuit board material brands they regularly use.
• Inquire whether you can specify the material brand for your order. If they allow this, it shows that they are confident in the quality of the materials they provide.

5. Can I get a microsection or cross-section test report of the circuit board material after fabrication?

A microsection or cross-section test of the circuit board material involves cutting a PCB into thin slices to examine the internal layers and material structure. This test is a great way to verify that the materials used during production conform to the required standards and have been processed correctly.

Why is this beneficial?

A microsection test of the circuit board material can reveal hidden issues like improper bonding between layers, insufficient copper plating, or inconsistencies in material thickness. These issues can affect the PCB’s performance, especially in high-reliability applications.

What should you ask?

Bonus Tip: Ask for a signed material declaration form for the circuit board material as part of your PO

To further protect yourself, ask your supplier to include a material declaration form for the circuit board material as part of your purchase order (PO). This form serves as a written statement of assurance that the materials used comply with the agreed-upon specifications and certifications.

Why is this an extra layer of security?

A signed declaration for the circuit board material adds an extra layer of accountability, ensuring that the supplier is legally bound to the material specifications outlined in your agreement.

Conclusion

Verifying the circuit board material used in your PCBs isn’t just about ensuring quality; it’s about protecting your reputation and ensuring the long-term success of your products. By asking the right questions and being proactive in material verification, you can reduce the risk of material substitutions and ensure your products meet the highest standards.

At Highleap Electronics, we understand how critical circuit board material verification is for the success of your product. We are committed to providing complete transparency in our sourcing and inspection processes, backed by our ISO9001, ISO13485, and IATF16949 certifications.

Contact us today to learn more about how we can help you with reliable, high-quality PCB manufacturing and circuit board material verification.