PCB prototyping means the short run production of printed circuit boards before mass production. Engineers use prototyping after they finish circuit design and complete the PCB layout. They send the layout files to a board factory to make a small batch for testing. Below I explain what you need to do before prototype production.
There are simple PCBs and there are complex PCBs. For simple boards, prototyping is easy. For complex boards, prototyping needs care. If you do not use proper inspection tools during prototyping, problems may only show up after the boards are made. That will be too late. So you must prepare well before prototyping starts.
Notes and precautions for PCB prototyping
- Two common ways to prototype: using a regular PCB manufacturer or using a specialized prototype shop. Find the provider that fits your needs. Prototype shops live on making samples, so they will accept very small runs, even two pieces.
- Regular manufacturers usually aim for batch orders. They may expect you to return the samples later or to place a larger order. Prototype shops only make sample pieces or small lots. Even if you bring a large order, a prototype shop may not be set up for full mass production.
- In quality assurance, regular manufacturers tend to do better than some sample shops. Some sample shops focus on quick sales and may accept the job, cut a sample, and collect payment without full testing. They may skip flying probe tests. If quality is not good, you must do a new trial run. Trial runs should be done carefully. A proper trial run will usually uncover problems and make the next run successful.
Precautions for engineering staff during PCB prototyping
- Choose the prototype quantity carefully to control cost.
- Confirm component packages in detail to avoid prototype failure from wrong footprints.
- Perform full electrical checks to improve board performance.
- Lay out the board with signal integrity in mind to reduce noise and raise stability.
Precautions for prototype manufacturers
- Check PCB files carefully to avoid data errors.
- Approve all process steps and match processing parameters with the in-house factory.
- Control output to lower cost and keep quality.
- Communicate all special notes and requirements with the prototype customer to prevent surprises.
Preparations before PCB prototyping
- Make the physical outline
A closed physical outline is a basic platform for later component placement and prototyping. Be precise. Use rounded corners for the outline. Rounded corners avoid cuts from sharp edges and reduce stress concentration on the board. - Bring in components and nets, then place components
When you import components and nets into the drawn outline, follow the prompts carefully. Pay attention to component package types and net connections. Following the prompts reduces mistakes. Component placement and routing affect product life, stability, and electromagnetic compatibility. These items need special attention. In general, follow placement order and pay attention to heat dissipation. - Route the PCB design and refine it
When routing the PCB, follow the processing parameter requirements. You may also consult a trusted prototype vendor. Doing this reduces scrap rate. After finishing routing, adjust text, some parts, and some traces. Do copper pours at the right time. Avoid doing copper pours too early because that may slow down editing and cause trouble in routing. The final edits aim to make production, debugging, and repair easier. - Check and verify the nets
Sometimes mistakes or carelessness change the net relationships on the drawn PCB compared to the schematic. So checking and verification are necessary. After drawing, verify nets first, then do later work.
Philifast prototyping flow
Step 1 — Contact the factory
Tell the factory the needed board size, process requirements, and order quantity. Wait for a professional quote and then place the order.
Step 2 — Material cutting
Based on the engineering data you provide, cut small production boards from suitable raw panels. Typical flow: large raw panel → cut per machining instructions → align and clamp panels → punch rounded corners or mill edges → output boards.
Step 3 — Drilling
Drill holes at required positions and sizes on the prepared panels. Typical flow: stack panels and fix with registration pins → load panel → drill holes → unload panel → inspect and rework if needed.
Step 4 — Copper deposition on holes
Use chemical methods to deposit a thin copper layer in the holes that need plating. Typical flow: rough grinding → hang panels → automatic electroless copper line → unload → soak in 1% dilute H₂SO₄ → copper thickening.
Step 5 — Image transfer
Transfer the circuit image from production film to the board. Typical flow: roughen board → lamination → rest → alignment → exposure → rest → develop → inspect.
Step 6 — Pattern electroplating
Electroplate copper, and then plate nickel/gold or tin over the exposed circuit copper to reach required thickness. Typical flow: load panel → degrease → water rinse twice → micro-etch → water rinse → acid clean → copper electroplating → water rinse → acid dip → tin plating → water rinse → unload.
Step 7 — Photoresist stripping
Use NaOH solution to remove the photoresist layer that covered the areas for electroplating so that the non-circuit copper becomes exposed for later steps.
Step 8 — Etching
Use chemical etchants to remove copper from areas that are not part of the circuit.
Step 9 — Solder mask application
Transfer the solder mask image (commonly called green mask) to the board. The mask protects traces and prevents solder from bridging during component soldering.
Step 10 — Silkscreen printing
Print reference text and markings on the board for easier identification and assembly. Typical flow: after final solder mask cure → cool and rest → adjust mesh → print silkscreen → post-print cure.
Step 11 — Gold-finger plating
Plate nickel and then gold on connector finger areas to the required thickness. This improves hardness and wear resistance.
Step 12 — Routing and board shaping
Use punching dies or CNC routing to cut the board shape to the customer’s required outline.
Step 13 — Testing
Use a flying probe tester to check for open circuits, short circuits, and other defects that are hard to spot visually. This verifies board functionality.
Final notes and reminders
- Always confirm component footprints. A wrong footprint can cause prototype failure and delay the project.
- Keep clear design rules for drill sizes, trace widths, spacing, and impedance control if needed. Use the manufacturer’s recommended values when possible.
- Include test pads and provide a clear test plan. This helps electrical testing and debugging.
- Mark special requirements like controlled impedance lines, blind or buried vias, or press-fit holes early so the factory can check capability.
- Keep BOM and assembly information up to date and attach clear mechanical drawings when you need precise board outlines or special holes.
Marketing close for Philifast
Philifast offers professional PCB prototyping and quick turn services. We work with engineers to reduce risk and shorten development cycles. If you need PCB, PCBA, or custom manufacturing services, contact Philifast. Our team will help with quotes, process checks, and fast production so you can move from prototype to mass production with confidence.
