What Determines the Cost of Turnkey PCB Assembly?
Direct answer: Turnkey PCB assembly cost is driven by bare-board technology, component purchases, fixed setup work, placement and manual assembly complexity, inspection and test scope, excess-material liability, and delivery terms. At prototype and low volume, fixed engineering and setup costs can matter more per board than placement count alone. Compare quotations by scope and assumptions, not only by the final unit price.
What decision does this guide support?
This guide helps buyers explain why two turnkey quotations differ and determine whether they cover the same work. A turnkey supplier coordinates fabrication, purchasing, assembly, and the agreed verification scope, but the commercial boundary can vary. The quote should make one-time costs, recurring costs, material exposure, and customer-supplied inputs visible.
Turnkey cost-driver map
Use the map to reconcile the principal cost buckets. If a supplier cannot state the underlying assumption, the apparent saving may simply be work or liability excluded from the quote.
| Control point | Required action or evidence | Hold condition |
|---|---|---|
| PCB fabrication | Separate board technology, panelization, finish, stack-up, quantity, and schedule assumptions. | The board quote is based on an unapproved interpretation. |
| BOM | Expose price, packaging, MOQ, attrition, freight, excess, and lifecycle risk by line. | Extended BOM cost cannot be reconciled. |
| Assembly setup | Separate stencil, programming, feeder, profile, and first-article effort. | Fixed work is hidden by a unit-price headline. |
| Assembly run | Relate placement, manual operations, panel handling, and complexity to the build. | A process assumption does not match the design. |
| Inspection/test | Price agreed coverage, fixtures, software, operator time, data, and re-test. | The quote says test without defining evidence. |
| Inventory/logistics | State ownership of excess, storage, packaging, export, and delivery. | A later liability cannot be assigned. |
PCB fabrication and manufacturing setup
Layer count, board dimensions, stack-up, controlled impedance, copper weight, hole structure, laminate, surface finish, panel utilization, electrical test, and fabrication lead time affect bare-board cost. Stencils, process setup, engineering review, and first-article preparation are largely fixed costs, so their per-board effect is greatest in small orders.
BOM value and purchasing conditions
The BOM total should reflect the exact orderable MPN, approved source, required packaging, current price break, freight, MOQ, and expected attrition. High-value semiconductors often dominate the total, while low-cost parts can still create excess through reel quantities. Confirm the quote date because component price and availability evidence becomes stale.
Placement, soldering, and manual operations
Automated placement cost is influenced by setup as well as component count. Fine-pitch or bottom-terminated packages, double-sided processing, selective soldering, through-hole insertion, hand wiring, press-fit operations, depanelization, cleaning, and special handling can add separate process steps. Ask which operations were inferred from the data and which were explicitly specified.
Inspection, programming, and functional test
“Inspection included” is not a complete scope. Define visual or optical coverage, any hidden-joint inspection, programming steps, electrical checks, functional test duration, fixture ownership, retained data, and retest rules. A test method should be selected for the defects or product functions it is expected to detect.
Excess inventory and material liability
Turnkey purchasing may require buying more material than the build consumes. The quote should identify excess, who owns it, where it will be stored, and what happens after a revision change. Customer-cancelled orders and non-cancellable or non-returnable purchases also need an agreed commercial rule.
Packaging, export, and delivery assumptions
Clarify whether the price includes moisture protection, ESD packaging, individual labeling, serialized records, export paperwork, freight, duties, taxes, and delivery to a named destination. Incoterms and destination materially change which party carries transport cost and risk. Compare landed scope on the same basis rather than mixing ex-works and delivered figures.
How to normalize competing turnkey quotations
- Build a common scope sheet. List board revision, quantity, sourcing model, process steps, verification, packaging, and delivery terms.
- Separate cost types. Compare one-time setup, recurring assembly, purchased material, excess, and logistics independently.
- Challenge the largest differences. Ask for the quantity, price date, process assumption, or exclusion behind each material variance.
Turnkey pricing questions
Why does the unit price fall sharply at a higher quantity?
Fixed setup is spread across more boards, price breaks may apply, and panel or packaging utilization may improve. The lower unit price is meaningful only if the design is stable and the extra assemblies or material have a planned use.
Does turnkey include functional testing?
Only when the quotation defines it. Functional testing normally requires customer product knowledge, pass/fail limits, software, fixtures, and failure disposition. Confirm responsibilities and deliverables before treating it as included.
How long is a turnkey quote valid?
Validity depends heavily on component availability and pricing. Use the stated validity period, but reconfirm critical lines at order because inventory can move before the quote expires.
Related Cyrionix resources
For a detailed sourcing review, see PCB component sourcing. The PCB assembly cost-driver resource provides a broader quotation checklist.
Technical references
- Altium ActiveBOM verification documentation
- IPC assembly acceptance and soldering standards
- KiCad fabrication and position-file documentation
Comparing turnkey scope? Review the turnkey PCB assembly service and submit a released package for quotation.
