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ServiceEMS contract manufacturing in Vietnam: PCBA, cable harness and test
Box build starts with the building blocks: boards, cables, enclosures and test. We match your RFQ with up to 3 Vietnamese EMS factories whose lines, certifications and volumes fit these requirements, within 24 business hours. Free for buyers.
What to look for in each work package
Factories are matched on the capability your RFQ needs, not on the lowest price.
PCBA
SMT and through-hole assembly, typically to IPC-A-610 Class 2, Class 3 on request. Ask for SPI, AOI and X-ray (for BGA and QFN) on the lines that will build your board, plus conformal coating and potting where required.
Cable and wire harness
Custom cable assemblies with crimp and connector matching, harness routing and labelling, built to IPC/WHMA-A-620. Continuity and hipot testing per harness.
Enclosures
Plastic injection or sheet-metal enclosures, usually from molding and metal shops the factory manages. Tooling ownership should be written into the contract.
Test and programming
Firmware loading, functional test fixtures designed per product, burn-in for power and thermal validation, calibration data logging by serial number.
Turnkey, partial turnkey or consigned
The BOM usually makes up the largest share of unit cost, so decide who buys the parts before you compare quotes.
| Model | Who buys parts | Good fit for | Watch |
|---|---|---|---|
| Full turnkey | Factory buys all components and materials | Most OEMs; one price per unit | Ask for authorised-channel purchasing and approved alternates |
| Partial turnkey | You consign key parts (e.g. MCU, radio module), factory buys the rest | Allocated or high-value parts | Define who owns shortage and scrap |
| Consigned | You supply all components, factory charges assembly and test | Buyers with their own supply chain | Attrition allowance and incoming inspection |
Vietnam's two electronics clusters
Location matters for site visits, sub-supplier access and export port. We match on capability first and tell you where each factory is.
| Region | Profile |
|---|---|
| North: Bac Ninh, Bac Giang, Hai Phong, Hanoi area | Large electronics plants (Samsung, Foxconn, Pegatron, Luxshare) and their supplier base; strong for high-volume consumer electronics. |
| South: Ho Chi Minh City, Binh Duong, Dong Nai | Many mid-size EMS and cable assembly factories; strong for mixed industrial, IoT and mid-volume programs. |
EMS and PCBA questions
What does an EMS provider do?
An electronics manufacturing services (EMS) provider builds electronic assemblies to the customer design: PCBA, cable and harness work, box build, test and often component purchasing. The OEM owns the design. The EMS provider supplies manufacturing capacity, process control and supply chain.
Which IPC class should I ask for?
Most commercial and industrial products are built to IPC-A-610 Class 2. Class 3 is for products that must keep working without interruption, such as some medical, aerospace or safety equipment, and costs more because of tighter criteria and more inspection. State the class on drawings and in the RFQ.
How do Vietnamese EMS factories avoid counterfeit components?
Ask each factory how it buys parts. The safer policy is to buy from the component maker or authorised distributors, keep traceability by lot and date code, and only use brokers with your written approval plus testing. Put the purchasing policy into the quality agreement.
Can you match factories with ISO 13485 or IATF 16949?
Yes, if you state it in the RFQ we only match factories that declare that certification, and you should check the certificate scope and validity with the certification body. For medical products, remember that regulatory registration stays with the product owner.