Project PCB Quality Control System

Introduction

our fabrication process include specific inspection and test steps. We use these to make sure that our processes are running correctly. These steps give you the added re-assurance that the board you receive is correct to your design and will perform correctly over the lifetime of your product. These steps are described below.

Standards

We as a pcb manufacturer inspect all boards to IPC-A-600 Class 2 This is the standard used for most PCBs, and is the standard most often specified by our customers. The IPC, or Institute for Printed Circuit Boards, is “a global trade association representing all facets of the industry including design, printed circuit board manufacturing and electronics assembly.” The IPC-A-600 standard “describes the preferred, acceptable and non-conforming conditions that are either externally or internally observable on printed boards”. It divides PCBs into 3 product classes. Class 2 includes “products where continued performance and extended life is required, and for which uninterrupted service is desired but not critical.” Class 3 (where uninterrupted service is critical) is used for aerospace, defence and medical applications

DRC Check

The Design Rules Check (DRC) is a very important step in PCB quality control. When we receive a new order from a customer, we will use an automated tool to verify that the layout does not have any specific placement, routing or other addressable layout errors.
This DRC checker will check the netlist and layout against the PCB design constraints and rules. It checks the board’s component placement and trace routing integrity for overlapping components, untraced pins, incorrect layer placement and constraints that are set for trace width routing and clearances. We also do the manufacturing rule check to make sure the PCB design is manufacturable. If we find any errors we will get in contact with the customer.

Electrical Testing

Prototype Orders: We offer Flying-Probe E-Test for small volume and prototype orders. Your circuit board (PCB) is checked through a device called a Flying-Probe E-Tester. The Flying probe testers we use have few restrictions on access, require no test fixtures, and can test boards with virtually unlimited number of nets. The Tester will check for short circuits, open circuits and make sure the nets of the PCB we made is the same as the nets in your design. After testing is complete, the fail rate of your boards will be less than 1%.
Production Orders: We use Testing fixtures to test production orders. A bed of nails tester is a traditional electronic test fixture which has numerous pins inserted into holes in an Epoxy phenolic glass cloth laminated sheet (G-10) which are aligned using tooling pins to make contact with test points on a printed circuit board.
The fixture contains an array of small, spring-loaded pogo pins; each pogo pin makes contact with one node in the circuitry of the DUT (device under test). By pressing the DUT down against the bed of nails, reliable contact can be quickly and simultaneously made with hundreds or even thousands of individual test points within the circuitry of the DUT.
The Tester will check for short circuits, open circuits, and make sure the nets of the PCB we made is the same as the nets in your design. After testing is complete, the fail rate of your boards will be less than 0.1%.

AOI(Automated optical inspection)

We use an AOI to check the inner layers of multi-layers PCB. AOI visually scans the surface of the PCB. The board is lit by several light sources and observed by a scanner or by a number of high definition cameras. This enables the monitoring of all areas of the board.
AOI for a bare PCB board inspection will detect these features:
* Line width violations
* Spacing violations
* Excess copper
* Missing pads. I.e. a feature that should be on the board is missing
* Shorts circuits
* Cut traces or pads
* Hole breakage.( Breakout ) I.e. a drilled hole (via) is outside of its landing pad
This inspection is much more reliable and repeatable than manual visual inspection.

AOI testing

ISO9001:2008

We are ISO 9001:2008 certified. And we briefly describe our quality control system as such:
* Our quality policy is a formal statement from our management, closely linked to our business and marketing plan and to our customer needs. Our quality policy is understood and followed at all levels and by all employees. Our employees will use measurable objectives to work towards.
* All Quality control data is recorded. Records will show how and where raw materials and products were processed, this allow products and possible problems to be traced to the source. Our quality control system is regularly audited and evaluated for conformance and effectiveness.
*Our quality control system records the customer requirements and creates a system for communicating with customers about product information, inquiries, contracts, orders, feedback and complaints.
* We regularly review performance of our quality control system through internal audits and meetings. We determine whether or not the quality system is working and what improvements can be made. We will deal with past problems and potential problems. Our system keeps records of these activities and the resulting decisions, and monitors their effectiveness.
* We documented the procedures for dealing with actual and potential non-conformances (problems involving suppliers or customers, or internal problems). Our system makes sure that all product(s) deemed “BAD” are quarantined and that no one can use the bad product until we can determine what to do with said bad product, We will seek and deal with the root cause of the problem(s) and keep records to use as a tool to improve our system.