First distinguish three types of 'boards'
The purchased individual board is the circuit board ultimately used. A delivered assembly panel is the group of individual boards the customer receives for assembly. A fabrication panel is the fabricator's processing unit. These are not necessarily identical. Internally combining several designs on a fabrication panel does not establish the customer's delivery format or mean that the quotation quantity is calculated from fabrication panels.
| Object | Items Requiring Confirmation | Common Misconceptions |
|---|---|---|
| Accepted individual board | Final dimensions, qualified quantity, and version | The ordered quantity automatically equals the delivered panel quantity |
| Delivery Panel | Boards per panel, process rails, marks, and depaneling method | Fabrication panelization can be used directly without assembly-provider approval |
| Production board | The fabricator reviews material utilization and process arrangements | Higher fabrication-panel utilization guarantees the lowest total cost |
Quantity conversion example
Suppose the target is 120 accepted individual boards with 6 boards per delivered panel; this corresponds to 20 all-good assembly panels. This is only a purchasing count example, with no yield, spare-quantity, or pricing commitment. If panels with defective positions are allowed, separately agree on marking, acceptance, and good-board counting. Counting “20 panels” alone does not establish delivery of 120 accepted boards.
Close Manufacturing and Assembly Interfaces Before Quoting
- Provide individual-board and assembly-panel drawings showing orientation, spacing, process rails, and keepout areas.
- Confirm tooling holes, fiducials, and placement-machine clamping requirements. Relevant processes must review dimensions; do not apply universal values.
- Agree on V-scoring, routed slots, tabs, and depaneling responsibility, considering component-to-edge distances and mechanical stress.
- If impedance coupons or other test structures are needed, specify whether they ship with panels so assembly space is not obstructed.
Engineering geometry for reference DFMA panel review example; this article addresses the purchasing basis without repeating detailed panel calculations. When selecting PCB Structure Then, via Request Quote also state individual-board quantity, delivery format, and subsequent assembly method.
Data Basis:Engineering reference | Gerber manufacturing data: layer functions, drilling, and attributes, checked on 2026-10-05. Used for the corresponding file, structure, or material descriptions in this article. The procurement checklist is a communication method, not a statement of universal fabrication capability or delivery commitments.
Data Basis:Engineering reference | Digital PCB stackups: material databases and controlled manufacturing structures, checked on 2026-10-05. Used for the corresponding file, structure, or material descriptions in this article. The procurement checklist is a communication method, not a statement of universal fabrication capability or delivery commitments.
Related procurement and acceptance Q&A
If a quotation counts fabrication panels, will delivery also be in fabrication panels?
A fabrication panel is a manufacturing processing unit, an assembly panel is the customer's assembly unit, and an individual board is the final product. Define all three separately; they are not automatically interchangeable.
View: First distinguish three types of boards
Do 20 panels with 6 boards each always fulfill a 120-board order?
They represent 120 accepted boards only if every position is good. For panels with defective positions, agree separately on marking, acceptance, and good-board counts; do not count panel sheets alone.
View: A quantity conversion example
Can the fabricator's panelization be used without assembly-provider approval?
Relevant processes must review the assembly panel's rails, marks, clamping, orientation, and keepouts. An internal material-utilization layout does not automatically become the approved assembly delivery drawing.
See: Resolve fabrication and assembly interfaces before quotation
What should purchasing confirm for V-scored or routed depaneling?
Define tabs, component-to-edge distances, mechanical stress, and depaneling responsibility, reviewing them with subsequent assembly. Comparing costs by depaneling method name alone is insufficient.
See: Resolve fabrication and assembly interfaces before quotation
Should impedance coupons be delivered with panelization?
Define coupon locations, traceability, and delivery responsibilities according to testing and assembly needs; keep them clear of assembly space. “Testing included” does not establish whether coupons ship with boards.
See: Resolve fabrication and assembly interfaces before quotation
Set different rules for all-good panels and panels with defective positions
Using the same example of 120 required boards and 6 per panel: 20 all-good panels contain 120 boards. If those 20 panels contain 2 defective positions, only 118 boards are accepted; the panel count alone does not establish complete delivery. The order must define whether defects are accepted, how they are marked, how assembly software skips them, and whether replacements are required.
If every panel must be fully good, confirm supply quantities, replacements, and acceptance on that basis. If defective positions are permitted, the count sheet should list each panel identifier, defective-position coordinates, and good-board count. Negotiate extras against actual needs and supply terms; this article assumes neither fabrication yield nor a fixed free-extra percentage.
State spacing and process rails in hypothetical panel-layout calculations
Suppose each board is 80×50 mm, arranged in 3 columns and 2 rows, with 2 mm spacing and 5 mm rails around all sides. The assembly panel outline is approximately 254×112 mm, with an area of 0.028448 m². The six boards have a net area of 0.024 m², giving a net-area ratio of approximately 84.4%. These dimensions illustrate arithmetic only; they are not recommended spacing or universal equipment requirements.
The actual layout must also include tabs, V-scores or routed slots, tooling holes, marks, test coupons, and clamping areas, confirmed by fabrication and assembly providers. Internal fabrication-panel utilization differs from this assembly panel's net-area ratio; 84.4% cannot directly establish the factory's billable area or material cost.
| Drawing Fields | Items to Provide | Confirmation Interface |
|---|---|---|
| Panel and Orientation | Board outline, version, rotation, and reference designators | Design and Assembly |
| Process Margin and Markings | Clamping, positioning, identification, and no-go areas | Subsequent Assembly Steps |
| Panelization Structure | V-score, slot, bridge, and component edge clearance | Manufacturing, assembly, and mechanical |
| Test coupon | Coupon ID, layer pair, location, and whether it is delivered with the board | Testing and Acceptance |
| Quantity and Defects | Accepted individual boards, all-good panel requirements, and replacement rules | Procurement and Quality |
Panelization approval must cover subsequent assembly
Design first confirms individual-board function and mechanics; the fabricator reviews manufacturability; assembly confirms transport, clamping, alignment, and depaneling. A fabrication panel optimized for material utilization must not become the assembly delivery panel without approval. If only depaneled individual boards are needed, specify depaneling responsibility, residual tabs, and protective packaging.
Thin boards, heavy components, or components near edges may be more sensitive to depaneling stress. Assess actual components and structure instead of judging risk from a depaneling method's name. After depaneling the first boards, inspect dimensions and affected connections, record the method and fixtures, and review again if the process changes.
How to write purchase orders to avoid unit confusion
A recommended description is “120 accepted individual boards, delivered in panels of 6, with an expected 20 all-good panels,” followed by defective-position acceptance and replacement rules. The quotation response should state the pricing unit, unit-price basis, panel drawing revision, reports, and shipping. For area-based pricing, confirm the supplier's billable-area definition; do not substitute net board area yourself.
On arrival, count by panel and position identifiers; coupons and rails do not count as accepted products. Before assembly, align defective-position marks with the program. After depaneling, retain links between individual boards and their original panels. The final output is an approved drawing supporting counting, placement, and depaneling, not merely “six-up.”
Defective-position marks must be recognized by the assembly program
Agree on defective-position coordinates using rows/columns or position identifiers from the panel drawing, maintaining the same orientation on every panel. If the assembly program's origin is reversed relative to purchasing records, it may skip good positions and populate defective ones. For the first lot, use a panel with known status to compare manual records with program recognition before batch use.
Also specify when coupons, rails, and tooling holes are removed. Removing them too early may lose clamping features or traceability marks; too late may interfere with assembly. Link quantities and identifiers before and after depaneling so accepted individual boards remain traceable to their original panels and inspection records.
Source material and applicable scope
- Ucamco, “Gerber Format — Official Gerber Format Website”; online webpage with no fixed revision identified; checked on 2026-10-18; relevant sections cover Gerber layer files, attributes, and Job file responsibilities. Supports only manufacturing graphics and semantic inputs. The quotation, scheduling, acceptance, and collaboration tables below are this site's engineering procurement recommendations, not universal pricing or service commitments.
- Würth Elektronik, “Digital PCB Standards — Stackups and Material Database”; online webpage with no fixed revision identified; checked on 2026-10-18; relevant sections: Digital stackups and Material database. Supports planning boundaries for stackups and material models. Procurement approval and quantity examples are this site's collaboration methods.
