Before quotation 路 Before production
PCB File Formats: Gerber, Drill Data and Manufacturing Packages
Identify what each PCB file carries, how the files work together and what to check before sending them for manufacture. Use the filename guide to prepare a review manifest without uploading design data.
Start with the information you have. Identify open questions and the intended build revision.
Which PCB file format should you send?
Use the manufacturing output format agreed with the receiving team. A common fabrication package combines Gerber artwork, drill data, an unambiguous outline and fabrication instructions. Intelligent manufacturing packages such as ODB++ or IPC-2581 can carry structured information, but the export content and the receiving workflow still need confirmation.
For assembly, include the required BOM, placement and assembly definition in the accepted form. A manufacturing package may contain some of that information, yet its presence and correctness should be checked rather than assumed. The required PCBA files guide explains the full enquiry-to-release package; this page focuses on formats and export interpretation.
Native PCB and schematic files serve engineering editing and design maintenance. Fabrication outputs serve manufacturing. A PDF is useful for human-readable instructions. An archive groups files for transfer. These are different roles, so asking for 鈥渢he PCB file鈥� without naming the task often causes incomplete handoffs.
For editable source work, distinguish organizing multiple boards as separate KiCad projects from migrating an EasyEDA design into KiCad ; these tasks precede the manufacturing-file release.
Identify filename clues and build a review manifest
Paste filenames, one per line. The tool suggests possible categories from extensions and flags duplicates or ambiguous names. It does not read a Gerber, parse drill coordinates, inspect an archive or prove that a layer is present. Content stays outside this tool; even a plausible filename requires a content review.
PCB Filename and Manifest Guide
Use the output to start a manifest, then add the verified layer function, revision, units and release status in your controlled documentation. A filename containing 鈥渢op鈥� is a hint only. Archive extensions such as ZIP tell you about the container, not the correctness or completeness of its contents.
Compare file types by the job they do
| Format / data | Typical purpose | Review question |
|---|---|---|
| Gerber | Manufacturing layer artwork and supported attributes | Which layer function and polarity does the content declare? |
| Drill data | Hole locations and tool definitions | Are plated/non-plated sets, units and coordinate format clear? |
| ODB++ | Structured design-to-manufacturing exchange | Does the agreed export contain the required board, assembly and related data? |
| IPC-2581 | Structured electronics manufacturing data exchange | Which revision, export scope and receiving support are agreed? |
| BOM / placement tables | Purchasing and component-placement definition | Do references, DNP states, side and rotation conventions agree? |
| Native CAD / schematic | Editable engineering source | Are libraries, project dependencies and revision identity available? |
| PDF / DXF / STEP | Readable instructions or mechanical exchange | Is it a reference or an authoritative dimensioned definition? |
Gerber extensions vary between CAD tools. Names such as .gtl and .gbl often identify top and bottom copper, while .gts and .gbs often indicate solder mask. A generic .gbr name may carry any layer. A file called .gm1 is not automatically the board outline; inspect its actual content and the project export convention.
Modern Gerber can include attributes that reduce ambiguity, and the Gerber job format can carry additional fabrication information. The official and are the appropriate references for format details. Do not create format rules by guessing from a filename.
ODB++ is documented by ; provides information about its exchange format. Agree which supported export to use. Sending several independently edited packages can increase ambiguity if their content is not synchronized.
Reading a file with a viewer and changing an editable design are different operations. Use the guide to choosing a PCB viewing route or the workflow for updating a KiCad PCB from its schematic to reach the task that matches your source files.
For layer-image questions, start with what a Gerber file describes. If the image function is unclear, use the Gerber naming and manual layer-mapping worksheet; for attributes and receiving-system support, review Gerber versus Gerber X2 compatibility.
Review the exported content, not just the extension
Open the exported manufacturing data in an appropriate viewer and review it as a package. Start with the outline and copper stack, then overlay drills, mask and legend. Check that all layers use the intended coordinate origin and units. Verify that slots, cutouts and board edges are represented in a way the receiving process understands.
Review plated and non-plated hole information deliberately. A drill filename can suggest its purpose, but the actual tool definitions, plating classification and fabrication drawing determine the manufacturing instruction. Do not rely on a renamed .txt file as evidence that drilling information is correct.
Check that the outline is unambiguous, that required openings are present and that no reference geometry is being mistaken for a cut. For a panel, distinguish the unit outline, array perimeter, routed slots and score lines. Link the package to the approved assembly panel definition when assembly is included.
Review solder-mask openings and legend placement with the intended layer semantics. A viewer display that looks inverted may reflect a polarity or display setting, so resolve the interpretation using format content and the export configuration rather than editing artwork based only on appearance.
The official describes fabrication and placement export workflows. Use the documentation for your actual CAD version and compare the generated output with the intended design. A successful export command is not a DFM result.
When holes appear shifted or mis-scaled, separate units, coordinate interpretation and origin with the NC drill file and coordinate guide. A decoded coordinate is a diagnostic aid, not a complete file or manufacturing check.
Create one authoritative manufacturing manifest
A practical manifest records the product and revision, filenames, verified purpose, preparation date and the responsible contact. Identify which documents control stackup, finish, tolerances, impedance requirements and special operations. Include the source of the required netlist comparison when that is part of the fabrication test agreement.
Keep superseded exports outside the release archive. If several revisions are included for comparison, label them clearly as reference material and identify the only approved build revision. A folder with both 鈥渇inal鈥� and 鈥渇inal2鈥� invites interpretation at exactly the point where the supplier needs certainty.
When an engineering change affects the design, regenerate affected outputs from the controlled CAD source. Record what changed and how existing material or work in progress should be handled. Editing one exported layer manually can leave the drill, netlist, assembly drawing or source design out of agreement.
Use the PCB DFM guide for manufacturability questions after the package meaning is clear. For assembly consistency, the DFA tools address selected BOM and placement issues. Format identification, content consistency and process feasibility are separate checks with different evidence.
For construction-specific outputs, review KiCad flex-region documentation ; for assembly data, use KiCad BOM and placement export checks so that geometry, population and revision definitions stay aligned.
For a repeatable export record, use the Altium Gerber and drill release checklist or the KiCad fabrication-output checklist. Record the actual application build and inspect the exact files supplied to manufacturing.
What if you only have photographs or an old manufactured board?
Photographs can communicate layout context, markings, damage or connector orientation. They cannot reliably reveal every inner-layer connection, component value, hole specification or assembly requirement. A PDF schematic can explain a circuit, but it cannot directly define the full copper geometry and fabrication process.
When the native design is missing, use the PCB-to-schematic recovery workflow to separate observations from inferred information. Recovery is an engineering task with explicit uncertainty and validation needs. It is not a matter of renaming an image into a Gerber file.
For an early discussion, describe what you have: native source, exported manufacturing data, schematic PDF, photographs, sample boards or partial records. Explain whether the desired outcome is repair documentation, a redesign or a repeat manufacturing release. This lets the engineering review start at the right level.
Send the agreed package to PCB Manufacturing for fabrication review, or follow the PCBA file checklist when the order includes components and assembly. If your only question concerns file interpretation, state it directly rather than waiting to prepare an entire production package.
Run a receiver-oriented release check before transferring files
A manufacturing archive is complete only relative to a defined task. A bare-board enquiry needs a different package from an assembled prototype or a repeat build with an approved customer panel. Write the requested deliverable at the top of the manifest before reviewing filenames. For example, 鈥渢wenty unpopulated boards, individually routed鈥� and 鈥渢wenty assembled units delivered in arrays鈥� describe different handoffs even when the circuit revision is identical. This small distinction prevents the receiving team from pricing an assumed scope.
| Deliverable | Additional information to reconcile | Common false assumption |
|---|---|---|
| Bare PCB | Layer functions, drill spans and plating, outline, material, finish and acceptance notes | The ZIP extension proves the set is complete |
| Populated PCB | BOM variants, placement orientation, assembly drawing and test scope | Gerber artwork identifies the purchased components |
| Impedance-controlled PCB | Stackup, reference planes, structures, targets and permitted adjustments | A trace-width screenshot defines the complete construction |
| Assembly array | Unit count, rails, fiducials, panel identity and delivery state | The fabricator should repeat an already repeated array |
Use a two-person or two-pass check: one pass establishes what the package is intended to mean; the other opens the exported outputs without relying on the original CAD view. Start with the board outline and one known dimension. Then overlay the drill data, copper and mask layers in their correct functions. Check an asymmetric feature so a mirrored or rotated view cannot appear correct merely because the board is rectangular. Select a mounting hole, a connector and an internal cutout as physical reference features. These are examples of useful checks, not a substitute for a complete design review.
A filename manifest can expose missing categories, but it cannot prove the actual geometry. Suppose an archive contains top.gbr, bottom.gbr and holes.drl. Those names do not prove a two-layer board, identify plating, or establish whether a mechanical layer contains a closed outline. A second archive with detailed extensions can still contain stale data. The useful distinction is between 鈥減resent by filename,鈥� 鈥渙pened and interpreted鈥� and 鈥渞econciled to release revision.鈥� Keep these statuses separate in the downloadable table instead of recording a single green check.
Modern Gerber includes ways to identify image functions and related metadata, and a Gerber job file can carry fabrication characteristics; see the . Those capabilities improve communication when export and receiving software support them. They do not authorize the receiver to choose between conflicting drawings. If a job file says one finish while the drawing says another, resolve the conflict and regenerate the package. Do not edit only the human-readable note and leave the machine-readable value stale.
Use checksums to identify the exact archive that was reviewed when your release process supports them. A checksum detects a byte-level change; it does not establish engineering correctness. If an approved file changes, the relevant review must be repeated. The comparison record should say what changed, why it changed and which outputs were regenerated. Avoid treating a saved email attachment as a substitute for a controlled source revision.
For a partial enquiry, a complete release package is not mandatory. Mark the design as preliminary and list missing decisions, such as material or test scope. Ask for a quotation with explicit assumptions rather than presenting provisional data as production-ready. Before ordering, close those assumptions against one coherent version. The DFM review workflow then addresses manufacturing feasibility; file identification remains a separate task. This sequence reduces avoidable clarification without suggesting that a file-name checker can inspect circuitry, verify connectivity or approve a build.
Questions before quotation and production
Is a .gbr file always a copper layer?
No. A generic Gerber extension does not establish layer function. Review attributes, content, export settings and the manifest.
Can I manufacture a board from a PDF?
A PDF can provide drawings and readable requirements. It normally does not replace the complete manufacturing geometry, drilling information and fabrication definition.
Does a ZIP file contain everything needed for a quote?
Not necessarily. ZIP is a container. Its contents must be identified, consistent and sufficient for the requested scope.
Can Gerber be converted back into the original CAD project?
Manufacturing geometry may support reconstruction, but it does not guarantee recovery of original schematic structure, library definitions, constraints or design intent. Agree the reconstruction scope separately.
Get a review around your actual requirements
Describe the product, revision, quantity and the question you need to resolve. Available files and clearly identified gaps are enough to start a useful engineering conversation.
Download the tool brief or open its enquiry email draft to carry the summary forward. The Contact form is a separate route and does not automatically receive the entries on this page.
Engineering references reviewed September 2026. Diagrams explain concepts; photographs illustrate published 吃瓜tv processes. Neither establishes a project-specific capability, acceptance result or certification.
Download the editable engineering review worksheet (CSV). This blank template stays on your device; attach it manually if useful.