Circuit board proofing charges

Understanding Proofing Costs in PCB ManufacturingIn the PCB (printed circuit board) manufacturing process, creating a production board initially requires produc...

Nov 21,2023 | Anne

Understanding Proofing Costs in PCB Manufacturing

In the PCB (printed circuit board) manufacturing process, creating a production board initially requires producing a prototype or "test" board, referred to as a proof. Proofing allows validating the design prior to full-scale fabrication. There are costs associated with these preliminary proof stages.

What are Circuit Board Proofing Charges?

Proofing charges include expenses tied to materials, labor, shipping and handling to create and send a sample PCB from the prototype fab to the customer. This allows physically verifying the board’s functionality for the particular application and environment based on the supplied design files before final production.

Typical proof charges comprise:

• Prototype Tooling/NRE Fees – Covers engineering prep work for manufacturing the test board. Usually a one-time upfront NRE (non-recurring engineering) cost.

• Base Board Price – Depends on materials required and dimensions. Quoted based on board space/area and number of layers.

• Test/Inspection – Testing functionality and quality assurance steps add cost. Includes examining solder mask adhesion, electrical tests, etc.

• Shipping Fees – Sending the wrapped and protected circuit proof to the customer’s address.

Proof Cost Savings Tips:

• Review manufacturing design rules to avoid errors necessitating revisions

• Utilize design for manufacturing guidelines to minimize complexity

• Only order quantity needed for evaluation (additional discounts over 10 pieces)

• Specify standard size to minimize tooling charges

• Streamline shipping selections (overnight/express options add expense)

While proofs entail costs, they enable validation to derisk the final board fabrication. Investing early in proofing reduces failure expenses later.

Here is a draft article discussing differences between plated through hole vs via,as well as specifying 2 oz copper thickness in mm:

Understanding Plated Through Holes vs Vias in PCB Design

When designing printed circuit boards (PCBs), two techniques used to electrically interconnect layers are plated through holes (PTHs) and vias. While seemingly similar, there are important distinctions.

Plated Through Holes (PTHs)

A PTH refers to a plated hole that goes through the entire PCB, connecting conductive layers to enable vertical interconnection. The interior of the hole is plated with an electrically conductive material to allow current flow between layers. PTHs establish connections through all layers in a multi-layer board. They are suitable for attaching larger components.

Vias

Unlike PTHs, a via transfers signals between adjacent layers only. Vias make contact with the conductive layers on either side, allowing for vertical transitions but not spannning the entire board. High density interconnect PCBs often contain many vias. Their small size suits interconnections for fine pitch surface mount components.

In summary, PTHs electrically connect all layers while vias only join adjacent layers. PTHs accommodate larger component leads whereas vias are more suitable for small pads/fine pitch ICs.

2 Ounce Copper Thickness

Copper thickness used in PCB fabrication is specified in ounces per square foot (oz/ft2). This refers to the weight of copper foil per area. 2 ounce copper equates to a thickness of 0.070 mm. This intermediate thickness offers a beneficial balance—thicker than 1 oz (0.035mm) for adequate current capacity but thinner than 3 oz (0.105mm) for fine features/spaces. The 2 oz standard provides a robust all-around option for typical PCB applications.

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