One process, two economies
Volume does not change how a board is assembled. It changes who pays for the setup and how the cost is spread.
On a small batch, the setup — stencil, program, first article, paste and profile verification — is a visible share of every board. On a large batch, the same setup is amortised to almost nothing, but the fixed investment in fixtures, tooling and dedicated test equipment is larger.
That is the whole trade. The practical question is which side of it a given product is on.
What a small batch pays for
- Setup time. Machine programming, stencil, first article and inspection programming happen once per build, whether the build is 20 boards or 20,000.
- Component purchasing. Small quantities come with minimum order quantities, cut tape and higher unit prices, and the line has to be able to run the packaging it receives.
- Test method. A flying probe needs no fixture, so it suits low volume; a hard-wired fixture costs money before the first board is tested.
What a large batch pays for
- Tooling. Fixtures, steel stencils, pallets and conveyors are one-time costs that only volume justifies.
- Test capacity. At volume the test step becomes a bottleneck, so fixtures and parallel test stations are bought for throughput rather than convenience.
- Inventory and change control. Volume locks the design: a change after tooling is expensive, so revisions are batched deliberately.
Where the crossover sits
It depends on four things, and none of them is a fixed quantity:
- Board size and panel utilisation — how many boards fit the panel decides the per-board share of every panel-level cost.
- Test method — flying probe versus fixture is often the single largest non-recurring cost in a small build.
- Component count and mix — a board with 40 lines on the BOM has a different setup cost from one with 400.
- Change frequency — a product that revises often should stay on the no-fixture path even at moderate volume.
Hitech Circuits treats small volume as orders under 6,000 boards, run on the same four SMT lines and three DIP lines as the larger lots. Prototypes come back in 1–3 days, medium volume in 4–10 days, and a BOM quotation is issued within 24 hours of a complete data package.
Choosing the order model
Volume and order model are separate decisions. Full turnkey means the Gerber set and BOM are all that is needed; partial turnkey covers the case where the customer supplies the bare boards or a critical component; consignment means the customer supplies the parts and the plant assembles, inspects and tests.
A small batch often works better as partial turnkey — the customer buys the expensive or long-lead parts — while a volume build usually moves to full turnkey so that one party owns the component risk.
The order models and limits are on the PCBA manufacturing page, and the fast path for small builds on the prototype assembly page.
