Anatomy of a PCB Assembly Quote
A PCB assembly quote from Calpak USA provides a per-unit price that includes assembly, programming, and testing — plus any NRE or fixture charges listed separately. Here is what drives those numbers and what to look for when comparing quotes across contract manufacturers:
Bare Board Fabrication
Layer count, material specification (FR-4, high-Tg, polyimide, Rogers), surface finish (HASL, ENIG, OSP, immersion silver), board thickness, copper weight, and panelization. The fabrication quote is often a separate line item or comes from a partner fab house, depending on whether the build is turnkey.
Component Procurement
Line-by-line BOM pricing based on manufacturer part numbers. Pricing depends on authorized vs. independent distributor sourcing, available inventory, minimum order quantities, and lead times. Long-lead or allocated components will impact both price and delivery schedule.
Solder Paste Stencils
Laser-cut stainless steel stencils with apertures matched to your PCB pad geometry. This is typically a one-time NRE charge per unique board design. Stencil thickness and aperture modifications (home plate, rounded corners) are adjusted based on fine-pitch component requirements.
Assembly Labor
SMT pick-and-place programming and run time, reflow soldering, through-hole component insertion, wave or selective soldering, and hand soldering for components that cannot be placed by machine. Labor cost scales with component count, board complexity, and whether the board is single-sided or double-sided.
Programming
IC programming via JTAG, ISP, or bed-of-nails fixture. If your design includes programmable devices (microcontrollers, FPGAs, EEPROMs), programming charges cover both the NRE for fixture or adapter setup and per-unit programming time.
Inspection
Automated optical inspection (AOI) compares each assembled board against a reference image to catch missing components, misalignment, tombstoning, and solder bridges. X-ray inspection is used for BGAs, QFNs, and other bottom-terminated components where solder joints are not optically visible. Visual inspection by IPC-certified operators is the final workmanship check.
Testing
In-circuit test (ICT), functional test, flying probe, and burn-in are common test line items. ICT and functional test typically carry an NRE charge for test fixture development, while flying probe is fixtureless. The scope of testing depends on your quality requirements and IPC class.
Conformal Coating
If your application requires conformal coating for moisture, dust, or chemical protection, the quote will include material, masking of keep-out areas (connectors, test points, mounting hardware), and application — either selective robotic coating or full-coverage spray/dip.
Packaging & Shipping
ESD-safe packaging, moisture barrier bags for MSL-sensitive assemblies, custom labeling (part numbers, serial numbers, date codes), and logistics. Packaging requirements vary significantly between a quick-turn prototype shipment and a production delivery with full documentation.
What Drives PCB Assembly Cost
Not all cost drivers carry equal weight. If you are looking to reduce your per-unit cost, focus on the items at the top of this list — they have the largest impact on your total.
| Cost Driver | Typical Impact | What You Control |
|---|---|---|
| Component cost | 60–75% of total | BOM optimization, alternate sourcing, value consolidation |
| Board complexity | 10–20% of total | Layer count, HDI, flex/rigid-flex, impedance control |
| Assembly complexity | 5–15% of total | Double-sided reflow, fine-pitch BGAs, mixed technology |
| Volume | Setup amortization | Quantity price breaks, blanket orders, scheduled releases |
| Test requirements | NRE + per-unit | ICT fixture NRE, functional test development scope |
| Turnaround time | 10–30% premium | Standard vs. expedited scheduling |
| Certification overhead | 5–15% premium | AS9100/ITAR documentation, traceability, lot control |
Component cost dominates the total. A design with 200 unique line items on the BOM will almost always cost more to build than one with 120 line items at the same component count — because more unique parts means more purchasing overhead, more feeder setups, and more opportunities for supply chain delays. BOM optimization is the single highest-leverage activity for cost reduction.
How to Get an Accurate Quote
The quality of your quote depends on the quality of the information you provide. Incomplete or ambiguous documentation leads to contingency pricing — we have to assume worst-case scenarios for anything that is not specified. Here is what to include for a precise, accurate quote:
Provide Complete Gerber Files
Submit Gerber files in RS-274X or ODB++ format — not PDFs of the board layout. Include all copper layers, solder mask, silkscreen, paste layers, drill files, and a board outline. A fabrication drawing with the layer stackup, material callout, and finish specification eliminates back-and-forth.
Submit a Clean BOM
Use a spreadsheet format (Excel or CSV) with columns for reference designator, manufacturer part number (MPN), description, quantity per board, and approved alternates. A BOM with only descriptions and no MPNs forces the CM to guess at parts, which introduces pricing uncertainty and delays.
Include Assembly Drawings
Assembly drawings should show component placement, polarity markings, keep-out zones, and any special instructions (e.g., "do not wash," conformal coating boundaries, press-fit connectors). If your board has components on both sides, provide top and bottom assembly views.
Specify Requirements Upfront
IPC class (Class 2 or Class 3), workmanship standard (J-STD-001), any customer-specific requirements, lead-free vs. leaded solder, and certification requirements (AS9100, ITAR). Leaving these unspecified means the CM either has to ask — delaying your quote — or assume standard terms that may not match your needs.
Flag Long-Lead Components Early
Sole-source, single-fab, or allocated components can push lead times from weeks to months. If you know certain parts on your BOM are constrained, call them out. This allows the CM to price and schedule accurately instead of discovering the constraint after you have placed the order.
Separate NRE from Recurring Cost
Ask for NRE charges (stencils, test fixtures, programming adapters) broken out separately from per-board recurring cost. This makes it easier to compare quotes across vendors and to forecast unit cost at different volumes.
How to Reduce Your PCB Assembly Cost
Cost reduction in PCB assembly starts at the design stage — not at the quoting stage. The following practices have the most consistent impact on per-unit cost across prototype and production volumes.
- ✓ Consolidate passive values. If your BOM uses fifteen different resistor values between 1k and 10k, see if you can standardize on fewer values. Fewer unique line items means better pricing leverage and fewer feeder setups on the pick-and-place machine.
- ✓ Use appropriately sized IPC standard pads. Matching pad geometry to component packages per IPC-7351 recommendations is critical to preventing solder defects and rework. Oversized or undersized pads lead to bridging, tombstoning, and insufficient joints — all of which add cost to your build.
- ✓ Design for panelization. Work with your CM to optimize panel utilization before finalizing the board outline. Poor panel yield — where odd board shapes leave large unused areas — drives up the per-board fabrication cost. A small adjustment to board dimensions can sometimes improve panel utilization by 20% or more.
- ✓ Minimize through-hole components. SMT assembly is faster and cheaper than through-hole at volume. Every through-hole component requires either wave/selective soldering or hand soldering — both slower processes. Use SMT equivalents where your mechanical and thermal requirements allow.
- ✓ Evaluate surface finish requirements. ENIG is the most common finish for fine-pitch assembly, but it costs more than HASL. If your design does not require wire bonding or the flat coplanarity that ENIG provides, HASL or OSP may be sufficient and will lower the bare board cost.
- ✓ Request a DFM review before production. A DFM review identifies manufacturability issues — tight clearances, insufficient annular rings, thermal relief problems — before your boards go into production. Catching these in design costs nothing. Catching them in rework costs real money. See our DFM guide for a complete checklist.
- ✓ Discuss volume forecasts. If you anticipate repeat orders, share your annual volume forecast. Blanket purchase orders and scheduled releases allow the CM to buy components in larger quantities and plan production capacity — both of which lower your per-unit cost compared to ordering one-off each time.
Questions to Ask Your Contract Manufacturer
When you are evaluating contract manufacturers, the questions you ask during the quoting process reveal a lot about how a CM operates. Here is a checklist you can use with any CM you are considering:
CM Evaluation Checklist
- ☐ What certifications do you hold, and what is the scope of coverage? (AS9100, ISO 9001, ISO 13485, ITAR registration — and do they apply to the specific facility where your boards will be built?)
- ☐ Do you perform a DFM review before assembly, and is it included in the quote or charged separately?
- ☐ How do you handle component shortages or obsolescence during a production run?
- ☐ What inspection methods do you use — AOI, X-ray, visual — and at what stages in the process?
- ☐ Can you support both prototype and production from the same facility, with the same quality system?
- ☐ What is your standard lead time, and what are the options and cost for expedited turnaround?
- ☐ How do you handle IP protection and controlled technical data under ITAR?
Ready to Get a Quote?
Calpak USA provides detailed, line-item quotes for prototype and production PCB assembly — including turnkey and consigned options. Every quote includes a complimentary DFM review at no additional charge.
Submit your design files through the RFQ form, or contact the engineering team directly to discuss your project requirements before submitting.
Related Resources
- PCB Design for Manufacturing (DFM) Guide — Checklist for optimizing your design before submitting for a quote
- IPC Class 3 Assembly Guide — Understanding high-reliability assembly requirements and their cost impact
- PCB Assembly Process Explained — Step-by-step walkthrough of the assembly process from paste to ship
- Production Assembly Services
- Prototype Assembly Services