First article inspection in PCBA manufacturing

Many friends don’t know much about what’s the first article inspection(FAI) in PCBA processing. Next, I will introduce the FAI process of PCBA processing in detail. The production of the first piece of PCBA processing is because the previous process and equipment are not as mature as they are now, and the factory often has problems such as batch defects, rework, and even scrapping in the production process. So, the first PCBA board that needs to be strictly inspected or tested at the start of mass production.

What is first article inspection?

FAI is the inspection, validation and testing of the first product. The FAI is to detect problems affecting product quality in the production process as early as possible and prevent batch defects or scrapping.

The first piece of SMT patch is an important means to control the production process of the product in advance, and it is also a very good method to control the quality of the product process.

It is an effective and necessary method for enterprises to ensure product quality and improve economic benefits. One of the indispensable processing links.

Data requirements for FAI:

First, the production department, engineering department, and quality department need to confirm the correctness of the data, that is, to ensure that the data is correct, there are correct samples to refer to, and it is best for the customer to provide physical samples.

Such as: product drawings, process documents, BOM, PCBA, special process requirements and other technical documents, etc., if there is any discrepancy, you need to feedback and confirm with the customer.

Keypoint for FAI:

  1. The first piece in the order, that is, the first board and the first Panel, but the general first piece will be pasted with two panels, one for SMT sample, one for functional testing, and full-function testing.
  1. When the production goes to work or when the shift is changed, Ongoing product’s first panel must be FAI, this purpose is prevent some defect of the shift from left to the shift.
  1. ECN changes, such as: re-paste the glue board for quality measurement and do FAI if the material is replaced with more than 15 pieces, the first piece of mass production orders and production can be carried out simultaneously, without affecting the production efficiency.
  1. Process changes, such as program re-optimization, station change, replacement of more than five feeders, require re-adhesive cardboard for quality measurement and FAI. The first-piece can be carried out simultaneously with production without affecting production efficiency.

Attention for FAI:

  1. Take protective measures, such as electrostatic protection.
  2. Whether the position, polarity, angle, etc. of the mounted components meet the requirements of the technical documents.
  3. Whether the quality of incoming components is qualified, such as: component color, component size, positive and negative poles, etc.
  4. Whether the solder quality of components meets the requirements of customers or related technical documents.
  5. The inspector shall mark the first piece that passes the inspection according to the regulations, and keep it until the batch of products is completed.
  6. FAI must be timely to avoid reducing production efficiency.
  7. If the first piece has not passed the inspection, no further processing or operation is allowed.

FAI mechanism for PCBA processing is interlinked:

  1. Self-inspection: Engineers conduct self-inspection on the first product they produce, mainly led by field engineers. Engineers can conduct self-inspection based on the above confirmed data, and the focus is on the direction of the components and the mount effect.
  1. Mutual inspection: After the engineer inspects, the operator will carry out mutual inspection, focusing on checking the BOM and drawings, whether there is a lack or miss materials, etc., and immediately notify the production engineer to solve any objection if find any problem.
  1. Full inspection: After passing the qualification, the quality inspection personnel will be sent for full inspection.

Generally, a multimeter or ECR bridge is used. Basically, large-scale factories use bridges. The focus is on the measured value of components and the direction of components.

If there is a BGA components, X-ray inspection is required to determine the soldering effect of the internal solder balls.

According to the customer’s original BOM, special processing requirements, samples, etc., the product is inspected to confirm whether the first piece of production meets the customer’s requirements, make a judgment on whether the product meets the requirements of the production technical documents, and at the same time, whether the production conditions and process parameters are qualified for mass production Product evaluation.

The PCBA samples that have passed the “three inspections” are retained until the end of batch production.

  1. The basis of the three-inspection system is the first piece, and the comparison standard of the first piece is the samples and guidance documents agreed in advance between the factory and the customer.

The correctness of the sample includes the correctness of the material and the correctness of the soldering.

The consistency between the customer guide document and the sample, the document is the priority, and the sample shall prevail if there is no document.

At any time, this basic principle can be followed, which is a protection for the foundry and a responsibility for the customer.

The purpose is to ensure and improve the quality, and avoid the occurrence of quality loss caused by the mistakes of both parties.

The long-term practical experience of PCBA processing has proved that the FAI system is an effective measure to detect problems asap and prevent products from being scrapped in batches.

Through the FAI, a series of systemic problems such as severe wear of fixtures or wrong installation and positioning, poor measuring instrument accuracy, misreading of drawings, wrong materials or recipes, etc. can be found, so that corrective or improvement measures can be taken in advance.

All in all, its main purpose is to discover the systematic factors affecting product quality in the process of PCBA processing and production asap, and prevent batches of substandard products or products from being scrapped in batches.