Electronics manufacturing services: handing over a board, a box or the whole product

Board level, box build, and the ground in between

At one end, the provider places components on a printed circuit board and returns it. At the other, they assemble the entire product: boards, cables, enclosure, firmware loading, functional test, packing and sometimes shipment direct to your customers. Every step outward removes work from you and adds a supplier now touching parts of the product you may have specified less carefully than the electronics. Mechanical items, cables and enclosures usually carry vaguer documentation than boards do, and full assembly is where that vagueness surfaces. Fix the boundary early, since moving it later means re-quoting, re-testing and generally a fresh set of drawings.

The data set that actually lets somebody build

A quotable package includes fabrication data for the bare board, a placement file giving position and rotation for every part, an assembly drawing showing orientation and any hand-fitted items, a paste layer for stencil production, and a parts list naming manufacturer part numbers rather than descriptions. The last omission causes the most trouble. A line reading capacitor with a value and a package leaves the assembler choosing, and availability and price will drive that choice. Add a test specification and a statement of what an acceptable unit looks like, or acceptable will be defined for you by whoever is running the line.

Turnkey or consigned: who buys the components

Turnkey means the provider purchases everything and quotes a built assembly. It removes purchasing work, applies their buying power to common parts, and buries the component market inside a price that reopens whenever that market moves. Consignment means you buy and ship parts in, keeping cost visible and sources under your control, while accepting that any shortage on your side halts their line and still consumes the booked slot. Hybrids are common: the provider buys passives and commodity items, you buy processors, modules and anything with a long lead or a history of allocation.

Test is something you specify and usually pay to develop

Assemblers run whatever test you define and nothing you did not. Optical inspection catches placement and solder defects and says nothing about whether the product works. Functional test needs a fixture, a script and a definition of pass, all of which are engineering projects with their own quotations. Deciding late means either shipping untested product or holding finished stock while a rig is built. Settle too who owns the fixture, what happens to units that fail, and whether test results are retained against serial numbers, since tracing a field failure without that record is guesswork dressed up as analysis.

The introduction build is where the relationship is decided

That first build reveals whether the documentation was adequate, whether the design tolerates real assembly processes, and whether the provider raises problems or quietly works around them. Expect a review returning a list: footprints that cannot be inspected, parts too close to a board edge, rails needed for panelling, a connector unreachable once the enclosure closes. Suppliers who produce that list before quoting are worth more than a lower number. Suppliers who build in silence and present the yield afterwards will keep doing exactly that, and the cost of the habit compounds with every batch.

Frequently asked questions

Should we buy the components ourselves or let the assembler do it?

Turnkey purchasing is simpler and usually quicker, since the provider already holds accounts, minimums and reel stock across many customers. Consigning parts earns its effort where a component is scarce, where you hold an allocation the provider cannot obtain, or where the item is a large enough share of cost that you want its price visible. Established programmes tend to end up mixed, with the buyer holding a few strategic items and the provider buying everything else.

What does an assembly partner mean by new product introduction?

The transition from a design that works on a bench to something their line can build repeatably. It normally covers a manufacturability review of the data package, procurement of first-build parts, stencil and programme setup, a small build watched closely by engineers, and a written account of what failed and why. The work is chargeable and worth paying for properly, because faults caught there cost a fraction of the same faults found in volume.

A part on our bill of materials has gone out of stock. What are the options?

In order of preference: an alternate qualified in advance, a functionally identical part from another maker that you evaluate and approve formally, a redesign of that section of the circuit, or open-market purchase at a premium with counterfeit exposure you then have to test for. The first option only exists if somebody did the work earlier, which is the argument for identifying single-source parts during design rather than during a shortage.