PCB assembly cost starts with the quoted scope
Two assembly quotations can use the same board quantity and still cover different work. Compare the released revision, procurement model, assembly route, inspection, functional test, accepted delivery quantity and shipping assumptions before comparing unit prices. A low placement rate can exclude costs that appear elsewhere in another quotation.
This guide provides a scope worksheet, not a price list. It publishes no automatic dollar amount and no universal per-pad rate. The final quote follows review of the actual files, materials, quantities and responsibilities.
Separate one-time, batch and per-board charges
| Cost group | Examples to clarify | Question for the supplier |
|---|---|---|
| Non-recurring engineering | Data preparation, process development, programming or fixture development | What deliverable is purchased, who owns it, and under what conditions can it be reused? |
| Setup per batch | Line setup, stencil handling, program loading and first-article checks | Which charges repeat on an unchanged reorder, and which changes trigger new setup? |
| Components | Approved BOM, purchase quantities, MOQ, excess and handling | Is the price based on consumed parts or purchased quantities, and who owns surplus? |
| Bare boards | Construction, quantity, panelization and electrical test | Are fabrication and board losses included, or are boards customer-supplied? |
| Assembly | SMT, through-hole, manual operations and special handling | What counting basis and process assumptions produce the quoted amount? |
| Inspection and test | AOI, X-ray, programming, ICT or functional test where agreed | Which units and features are covered, and are fixture and engineering charges separate? |
| Delivery | Identification, packaging, freight, duties and taxes | What destination and trade terms apply, and which items remain excluded? |
A quote-comparison example without invented rates
Consider two quotations for the same released control board. Quote A includes procurement and assembly but excludes functional testing and freight. Quote B includes those activities but lists fixture development separately. Comparing only their displayed per-board amounts would hide the scope difference. Complete the following worksheet before requesting revised comparable totals.
| Comparison field | Record for quote A | Record for quote B |
|---|---|---|
| Released package and variant | Revision, BOM variant and DNP list | Same scope, or identify the difference |
| Quantity basis | Boards started and accepted units delivered | Same acceptance and loss assumptions |
| Material basis | Full or partial turnkey, MOQ and excess | Same ownership and substitution rules |
| Test basis | Methods, coverage, time and records | Same procedure or explicit uncovered requirements |
| One-time work | Named deliverables and reuse conditions | Named deliverables and reuse conditions |
| Delivery basis | Packaging, destination and included logistics | Same destination and agreed inclusions |
Ask each supplier to return the missing items or explain why a different route is necessary. Do not fill a blank line with zero: it may mean excluded, unknown or included elsewhere.
Why pad counts do not determine the complete bill
Component count, pad count, placement count and a supplier-defined billable point are different measures. Ask for the counting definition before using a point-based estimate. Double-sided setup, difficult handling, through-hole work, moisture-sensitive material, first-article effort and test requirements can change the work independently of pad count. No universal counting convention is asserted here.
A valid cost comparison also identifies repair authorization and the treatment of failed units. State whether the unit amount is divided by boards started or accepted boards delivered. Keep expected material loss, surplus ownership and replenishment responsibility separate.
Reduce avoidable work while retaining validation
Release consistent BOM, placement and fabrication files. Resolve DNP and polarity questions early, agree alternate approval rules and define the first-build objective. Reusable fixtures or setup data may reduce repeated engineering work, but reuse depends on unchanged files, software, materials and equipment conditions. Ask which conditions have to remain fixed.
Use the RFQ documentation checklist, compare turnkey and consigned responsibilities, and define inspection and test coverage. The turnkey service scope connects these items to the order.
Calculate a comparable cost per accepted assembly
Normalize each quote to the same revision, supply model, test coverage, delivery terms and accepted quantity. Then calculate a comparable total, rather than comparing a displayed placement rate:
Comparable total = one-time work assigned to this order + batch setup + purchased material and bare boards + assembly + agreed test and rework allowance + packaging and delivery.
Comparable cost per accepted assembly = comparable total ÷ accepted units delivered. If a supplier charges by boards started, ask how expected setup loss, rejected boards and replacement materials reach the accepted-unit denominator. Do not divide by planned starts and then compare it with another quote divided by delivered units.
Keep reusable tooling and fixtures visible as separate lines. A first order may carry all of their cost while a reorder may reuse them only if the board, process, equipment and ownership terms remain compatible. For a fair repeat-order comparison, ask what fee recurs and what design change invalidates reuse. Record exclusions as “excluded” or “unknown”; a blank is not zero.
Prepare your assembly RFQ
Provide the current board files, BOM, assembly quantity, supply model, test needs and delivery destination. List target dates and unknown inputs. Use the engineering RFQ for available files or the short inquiry to clarify the scope first.
Method note: the comparison worksheets are KFPCBA editorial guidance for recording project assumptions. They are not industry-average prices, a supplier quotation, a completed project record or a guarantee of savings.
