Why buyers place PCB assembly in China
China PCB assembly is a supply-chain decision before it is a price decision. The Shenzhen area holds the laminate suppliers, the component distributors and the assembly houses within a short drive of each other, which shortens the loop between a missing part, a fab question and a re-quote. Hitech Circuits sits inside that loop: fabrication, PCB assembly, component sourcing and box build run in one plant rather than across four vendors.
The practical effect is fewer hand-offs. A bare board that fails at in-circuit test is checked against the fabrication record the same day, and a component that does not match the BOM is replaced before the line restarts — not after a shipment has crossed a border.
What a China PCB assembly plant covers
The same site handles four stages that are usually split across vendors:
- PCB fabrication — rigid boards from 1 to 38 layers, HDI, heavy copper, aluminium and copper metal-core, ceramic, flex and rigid-flex. The board families are listed under PCB manufacturing.
- Assembly — SMT, through-hole and mixed-technology builds, from express prototypes to volume PCBA.
- Component sourcing — BOM review, authorised-channel purchasing and alternates, described under components sourcing.
- Box build — cable harnesses, enclosure assembly, test and packing, covered by box build assembly.
Because the stages share one plant and one quality system, a China PCB assembly order does not need a separate fabrication supplier, a separate parts broker and a separate box-build house.
China PCB fabrication limits behind the assembly line
| Item | Capability |
|---|---|
| Layer count | 1–38 layers rigid · 1–12 layers flex and rigid-flex |
| Minimum line / space | 0.075 mm rigid · 3 mil (0.076 mm) flex |
| Minimum finished hole | 0.1 mm laser · 0.15 mm mechanical |
| Aspect ratio | 15:1 |
| Outer / inner copper | 0.5–20 oz outer · 0.5–10 oz inner |
| Board thickness | 0.1–6.0 mm |
| Maximum panel | 580 × 1900 mm |
| Impedance tolerance | ±10 % |
| HDI stack-ups | 1+N+1, 2+N+2, 1+1+N+1+1, 3+N+3 |
| Surface finish | HASL, lead-free HASL, ENIG, immersion silver / tin, flash gold, OSP, carbon ink |
Those limits decide which orders stay in one build. A 20 oz heavy copper board and a metal-core LED board can both be assembled in the same plant, and a ceramic PCB does not have to be re-quoted by a second supplier before assembly. High-layer multilayer and HDI designs are quoted with the stack-up fixed before lamination, so the impedance target survives assembly.
SMT, through-hole and test
- SMT — four lines placing six million chips per day, handling 01005 and 0201 packages at 4 mil (0.1 mm) pitch on one or both sides of the board.
- Through-hole — three DIP lines placing 1.6 million pieces per day, with wave, selective and hand soldering for connectors and odd-form parts.
- Inspection — solder paste inspection, AOI and X-ray, with ionograph contamination testing where the application requires it.
- Test — in-circuit, flying probe and functional test against the customer procedure, plus burn-in and thermal cycling when the product calls for it.
The PCBA testing and quality assurance page lists the inspection sequence; the assembly services page covers how reflow, wave and selective soldering are chosen per design.
Certifications that travel with the order
Boards built in Shenzhen are covered by ISO 9001:2015 as the base system, IATF 16949:2016 for automotive programmes and ISO 13485:2016 for medical devices, with ISO 14001 and ISO 45001 alongside them. Fabrication follows IPC-6012B and IPC-A-600H, and boards are UL recognised under file E354070 and RoHS compliant.
For buyers who need to audit the paperwork before placing an order, the scans are published on the certifications page, and the automotive and medical equipment pages describe how those systems apply to a build.
Component sourcing: what turnkey actually means
A turnkey China PCB assembly quote includes the parts, so the BOM becomes the risk item. Hitech Circuits checks every line for manufacturer part number, lifecycle status and alternate before the quote is issued, then buys from original manufacturers and first-class franchised agents under a supplier certification system. Incoming material is inspected at IQC, and moisture-sensitive devices are stored in temperature- and humidity-controlled chambers before kitting.
Consignment is supported when a customer already owns the stock, and end-of-life parts are handled by buying remaining stock or qualifying an alternative. The component sourcing page lists the incoming inspection steps, and turnkey electronics assembly explains how fabrication, parts and assembly are priced as one order.
Box build and system integration
Boards are rarely the end of the shipment. Cable harnesses, enclosures, labels, firmware loading, functional test and retail packing can be added after assembly, so the customer receives a tested unit rather than a carton of boards. Because box build runs next to the SMT lines, a harness that does not fit or a connector that fouls the enclosure is caught before the units are packed.
The box build assembly page covers harnesses, electro-mechanical assembly and final test; the same plant also handles the PCB fabrication behind it.
From Gerber to first article
- Send the data — Gerber set, BOM with manufacturer part numbers, pick-and-place file, assembly drawing, quantity and required lead time.
- Engineering review — DFM, DFA and DFT checks on the package, with fabrication limits and component availability confirmed before pricing.
- Quote — fabrication, parts, assembly, test and box build priced as one line, so freight and duty are not hiding a second supplier.
- Tooling — SMT stencils are cut and delivered within four hours; fixtures and test jigs are prepared in parallel.
- First article — SPI, AOI and X-ray on the first build, with the inspection record issued in English.
- Production and test — volume assembly on four SMT lines and three DIP lines, then in-circuit, flying probe or functional test before packing.
The quick-turn prototype service covers 1–3 day fabrication, and express prototype assembly covers 1–50 piece builds for the first article.
Documentation and communication
Quotations, DFM reports and inspection records are issued in English, and one sales contact stays with the order from quote to shipment. Certificates, RoHS statements and inspection records travel with the shipment when the buyer needs them for incoming inspection. Shipments leave Shenzhen by express or freight; the shipping method and export documents are confirmed with the order. Visits to the Shenzhen and Meizhou plants are welcome by appointment, and a mutual NDA can be signed before files are exchanged.
Buying terms and paperwork
The quotation is built as one line for fabrication, parts, assembly, test and box build, with quantity breaks and a lead time for each stage. Payment is by bank transfer (T/T); goods are quoted EXW Shenzhen, or DDP where the buyer wants a delivered price. The shipping method — express or freight — is fixed with the order, so the delivery date is not rewritten after production.
Export documents, certificates, RoHS statements and inspection records travel with the shipment when the buyer needs them for customs or incoming inspection. Express assembly covers 1–50 pieces and stencils are cut within four hours, so a first article does not need a volume commitment before the board is proven.
Before you send the files
A short checklist keeps the first quote comparable across suppliers:
- Confidentiality and ownership — a mutual NDA can be signed before the Gerber and BOM files are exchanged, and ownership of stencils, fixtures and test jigs is stated for when the programme ends.
- Data package — Gerber, BOM with manufacturer part numbers, pick-and-place file, assembly drawing and the test specification.
- Compliance route — IPC class, UL recognition, RoHS/REACH and any automotive or medical traceability requirement.
- Trade terms — EXW Shenzhen or DDP, destination, packing and the documents the customs broker will ask for.
- Acceptance — first-article approval, the sampling plan and the inspection record that must ship with production.
Start a China PCB assembly quote
Send the Gerber set and BOM through the contact page, or read the PCB manufacturing capability page first if the stack-up is still open. Both the PCB manufacturing and PCB assembly overviews list every board family and service that can be quoted from Shenzhen.