How do I estimate PCB assembly cost per board?

Add the bare board, components with attrition, SMT, through-hole and test time, divide by the final yield, and add setup and NRE per board. In the example, the motor driver costs 13.00 bare board, 18.68 components, 3.68 SMT, 1.12 through-hole and 0.69 test; at 97% yield that is 38.31 per good board, plus 2.80 of NRE over 500 boards: 41.11, so a 48.90 price makes 15.9%.

How is SMT placement cost calculated?

Placements per board / effective placements per hour x SMT line cost per hour. With 210 placements, 12,000 placements per hour and a 210 per hour line, SMT costs 210 / 12,000 x 210 = 3.68 per board. Use the rate your line really achieves on your boards, after feeder changes and board transfer, not the machine's rated CPH.

Why do small lots miss the margin target?

Setup and NRE (stencil, programming, first article) are paid once per lot. The example's medical sensor interface carries 3,200 of NRE over 100 boards, 32.00 per board, plus 300 seconds of functional test and 94% yield: 144.00 per good board against a 152.00 price, 5.3% margin. Bill the NRE separately (set it to 0 here) or quote a larger lot.

What does yield loss cost?

Every board built but not shipped has used its bare board, components, placements and test, so good boards carry it: yield loss = built cost x (1 / yield - 1). The gateway mainboard's 92.49 built cost at 95% yield adds 4.87 per good board, 1,217 over its lot of 250. Across all ten example lots, yield loss is 4,024.

How does the PCB Cost Per Board calculator relate to this template?

The calculator divides a total bare PCB cost by the usable boards it represents: 1,850 for 720 boards is 2.5694 per board. The Bare PCB column does the same for one panel (a 92.50 panel of 36 boards gives 2.5694), and the Verify sheet checks it. Components, assembly, test, NRE, yield and margin are this workbook's own build-up.

Industry Cost Kits

PCB Assembly Cost Excel Template

Build the cost of every printed circuit board assembly from the bare panel, the BOM with attrition, SMT placements, through-hole joints, test time, setup and NRE and the final yield, then check each price against your target margin.

Overview

This PCB assembly cost template is for EMS and contract electronics estimators, OEM buyers checking EMS quotes and electronics plant managers. It ships with ten example assemblies for a fictional contract manufacturer, from a keypad controller to a gateway mainboard, so every number moves before you type your own.

Each board is a row on Assemblies. The bare PCB is the panel price divided by the boards per panel; components are the BOM cost plus attrition; SMT is the placements divided by the line's effective placements per hour times the line rate; through-hole is joints times seconds per joint at the labour rate; test is seconds at the test station rate. Boards that fail are carried by the good ones (divide by the final yield, shown as yield loss), and the lot's setup and NRE are spread over the good boards ordered.

Margin on price is judged against your target margin, with lot cost, value and margin per board. The Dashboard shows the weighted margin, the assemblies below target, the material share of cost and the yield loss, with a stacked chart of where each board's cost goes. The live PCB Cost Per Board calculator computes the bare board share the same way, and the Verify sheet checks the workbook against its worked example.

What this template includes

Assemblies table: lot size, boards per panel, bare panel price, BOM cost, attrition, SMT placements, through-hole joints, test seconds, setup and NRE per lot, final yield and price for each board
Setup sheet with your SMT line cost per hour and effective placements per hour, hand assembly labour rate and seconds per joint, test station rate and target margin
Per board: bare PCB, components, SMT, through-hole, test, setup per board and yield loss, cost per good board, margin with On target, Near target or Below target, and lot cost, value and margin
Check column that names a missing input or a duplicate assembly in words
Dashboard: weighted margin, assemblies below target, material share of cost, yield loss, a chart of where each board's cost goes and margin by assembly
Method sheet with every formula, and a Verify sheet that rechecks the model, including the live PCB Cost Per Board calculator's example
CSV with live formulas of the Assemblies table; the dashboard, charts and self-check are in the .xlsx

Suggested use case

Use it to quote or should-cost PCB assemblies, to compare EMS quotes line by line, and to see whether components, placements, test, NRE or yield loss drive each board's cost.

How to use it

On Setup, type your currency, SMT line cost per hour and the placements per hour the line really achieves, the hand assembly and test rates, and your target margin.
On Assemblies, add one row per board: lot size, boards per panel, bare panel price, BOM cost and component attrition.
Add SMT placements, through-hole joints, test seconds, setup and NRE per lot, final yield and the quoted price.
Read the cost per good board, margin and status, and fix anything the Check column reports.
Open the Dashboard to see weighted margin, the assemblies below target, the material share and the cost of yield loss.

Frequently Asked Questions

How do I estimate PCB assembly cost per board?: Add the bare board, components with attrition, SMT, through-hole and test time, divide by the final yield, and add setup and NRE per board. In the example, the motor driver costs 13.00 bare board, 18.68 components, 3.68 SMT, 1.12 through-hole and 0.69 test; at 97% yield that is 38.31 per good board, plus 2.80 of NRE over 500 boards: 41.11, so a 48.90 price makes 15.9%.
How is SMT placement cost calculated?: Placements per board / effective placements per hour x SMT line cost per hour. With 210 placements, 12,000 placements per hour and a 210 per hour line, SMT costs 210 / 12,000 x 210 = 3.68 per board. Use the rate your line really achieves on your boards, after feeder changes and board transfer, not the machine's rated CPH.
Why do small lots miss the margin target?: Setup and NRE (stencil, programming, first article) are paid once per lot. The example's medical sensor interface carries 3,200 of NRE over 100 boards, 32.00 per board, plus 300 seconds of functional test and 94% yield: 144.00 per good board against a 152.00 price, 5.3% margin. Bill the NRE separately (set it to 0 here) or quote a larger lot.
What does yield loss cost?: Every board built but not shipped has used its bare board, components, placements and test, so good boards carry it: yield loss = built cost x (1 / yield - 1). The gateway mainboard's 92.49 built cost at 95% yield adds 4.87 per good board, 1,217 over its lot of 250. Across all ten example lots, yield loss is 4,024.
How does the PCB Cost Per Board calculator relate to this template?: The calculator divides a total bare PCB cost by the usable boards it represents: 1,850 for 720 boards is 2.5694 per board. The Bare PCB column does the same for one panel (a 92.50 panel of 36 boards gives 2.5694), and the Verify sheet checks it. Components, assembly, test, NRE, yield and margin are this workbook's own build-up.