Printed Circuit Board (PCB) Manufacturing Quality Management

We go through strict test in our manufacturing processes for a quality control. For new orders, we initially check layout by using an automated testing machine to ensure the layout does not have any problems on routing, placement, or any other layout problems. We compare the layout and the net list to PCB design limitations and the rules. Limitations have been determined for routing widths and clearances. So we must make sure there are no overlapping, untraced connecting pins, incorrect layer placements. If any error, we immediately contact the customer to solve out and confirmation. We must ensure the PCB is capable of being manufactured.

Flying Probe Test

For small quantity, we provide the Flying Probe Test. It does not need test fixtures. Using the Flying Probe test, we ensure PCB has no short or open circuits, as well as verify that the PCB nets correspond to the design. The Flying Probe test possesses few limitations on access. It can test PCBs with almost an unlimited amount of nets. In general, the Flying Probe test will catch errors. For example, the failure rate of the PCBs is generally less than one percent.

Fixture Test

Fixture Test has many small and spring loaded pogo pins that are inserted into holes on an epoxy phenolic glass cloth laminated sheet. These are lined up with tooling pins. These pins connect with the PCB test points. Every one of the pogo pins will connect to the device of the PCB that is going to be tested. Upon initiating the device-under-test via the fixture test, many separate test points will be connected for testing. This test ensures there are no shorted or opened circuits, and will also ensure the PCB nets correspond with the design nets. This test generally maintains the PCB failure rate to less than one-tenth of one percent.

Automated Optical Inspections

Automated optical inspections (AOI) provide an internal quality check of the inside layers of PCBs with multiple layers. This type of inspection performs a vision scan of the PCB surface using scanners so the entire area of the HDI PCB can be checked. The primary advantage of AOI is that it is highly reliable and accurate and a more sophisticated type of testing than visual inspection testing. For a basic board inspection, AOI can test for the following failures:


Line width out of rules specifications
Spacing errors outside of rules specifications.
Excessive amount of Cu.
Missing pads when they are required
Shorted circuit paths
Traces or pads that were partially or fully severed.
Holes that are broken out, which is usually caused by a hole that has been drilled beyond its target pad.

How to design a PCB( Printed Circuit Board ) ?

WDF-FPC-M-37,4 layer,wonderfulpcb.com

Initially PCBs were designed manually by creating a photomask on a clear mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints increased efficiency. Traces were made with self-adhesive tape. Pre-printed non-reproducing grids on the mylar assisted in layout. To fabricate the board, the finished photomask was photolithographically reproduced onto a photoresist coated on the blank copper-clad boards.

Nowadays PCBs are designed with dedicated layout software, generally in the following steps:

1.Schematic capture through an electronic design automation (EDA) tool.

2.Card dimensions and template are decided based on required circuitry and case of the PCB.

3.The positions of the components and heat sinks are determined.

4.Layer stack of the PCB is decided, with one to tens of layers depending on complexity. Ground and power planes are decided. A power plane is the counterpart to a ground plane and behaves as an AC signal ground while providing DC power to the circuits mounted on the PCB. Signal interconnections are traced on signal planes. Signal planes can be on the outer as well as inner layers. For optimal EMI performance high frequency signals are routed in internal layers between power or ground planes.

5.Line impedance is determined using dielectric layer thickness, routing copper thickness and trace-width. Trace separation is also taken into account in case of differential signals. Microstrip, stripline or dual stripline can be used to route signals.

6.Components are placed. Thermal considerations and geometry are taken into account. Vias and lands are marked.

7.Signal traces are routed. Electronic design automation tools usually create clearances and connections in power and ground planes automatically.

8.Gerber files are generated for manufacturing.

For further detailes, please contact wonderful09@wonderfulpcb.com.

PCB Replacement and Repair

The world is changing and technology is always changing too! But sometimes there are certain components which need some minor tweaks and changes to last even longer throughout the years. This can even happen with a client's manufactured electronic products when they need to be upgraded to a newer manufactured device.

When this happens, your manufacturer can help with the entire process of helping all of your clients to prevent sluggish PCB systems. However, there are other reasons why a PCB needs to be repaired, other than having to upgrade the entire system.

Wonderful PCB (HK) Limited is a professional PCB manufacturer with assembly line in house. It provides high quality PCB with good after-sale service. In face of complainant from clients, Wonderful PCB provides completed after-sale service including PCB replacement or repair.

Saving Time, Money & Repairing Defects

When you're going to ship out huge batch orders of units, sometimes taking the extra time to keep account of all of the components and making sure that every single component are finely assembled on the PCB board. And make sure every single one doesn't have a defect which can be very time consuming. However, you can save time from having to recall certain parts or dealing with defunct PCBs by Wonderful PCB when they can correct a design flaw to make sure PCB-repair the system isn't running slow.

This is also good for you, because it means your own clients utilizing PCBs won't be complaining about sluggish systems that can cost them time and money too. You can also implement cost effective solutions when a PCB manufacturer needs to be repaired, which can mean not having to replace an entire batch order and do a complete redesign simply because of a minor defect that can be repaired by the manufacturer.

New Software, New Repairs

When your PCB components and software are due for a brand new update, please don't worry more about it: Wonderful PCB can take care of everything. Sometimes software on the PCB can become slow and sluggish when it is new and the platform it is running on is older than the software itself, making it frustrating for all parties involved.

You or your clients using the PCB components need to stay up with all of the latest software, especially when everything is becoming so fast paced in the technology industry as is. PCB board repair can ensure that everything is fast, highly responsive, and in working order with the best components available on the market.

However, PCB repair and replacement which does mean that the entire batch order will need to be repaired in order to ensure that the software continues to run seamlessly and smoothly. This can take some time to do with bigger orders, but like mentioned earlier, the investment in PCB repair services creates better time management in the long run.