What are the Detection Methods for Circuit Board Quality Defect Warpage?
2020-02-12
Recently, some customers have consulted Thick Copper PCB, will it be warped, and maintain the original flatness? Copper is usually left on the side of the craft to ensure the warpage of the board. Qualified products with IPC standard warpage of less than 0.75%. Talking about warp copper clad warp points bow and twist. How to calculate PCB warpage? What measurement methods are available? Many beginners and some colleagues who have been making circuit boards for several years usually do not understand the problem. PCB warpage will cause inaccurate component positioning, which will bring a lot of difficulties to assembly and installation. Today, PCB Company helps you sort it out.
If the circuit board is warped, the measurement method is to lay it flat on a marble or glass plate, and the four corners of the circuit board are on the ground to measure the height of the middle arch; the calculation method is: warpage = arch height / PCB long side length * 100%.
Place the PCB to be measured on the marble table and use the plug gauge for
measurement. The standard calculation is:
The following describes several commonly used measurement methods:
1. Use marble or 5mm thick glass plate platform, use the plug gauge to measure the largest dimension of the corner, and then use the ruler to measure the diagonal length and divide the two numbers. If it is greater than seven thousandths, it will fail.
2. Touch the surface of the board with your hands, the sound from the gap between the ear board and the marble countertop will be leveled by hand.
3. Optical detection method, using the principle of light interference, testing warpage and distortion, accuracy can reach 0.1mil, often used for mass production shipment inspection, or laboratory reflow soldering for analysis.
With the development of the times, there have been more and more electronic products in recent years, so PCB circuit boards are widely used in communications and consumer electronics, medical equipment, computers, automotive electronics, industrial control, and aerospace and other fields. Relying on the PCB Bare Board as the carrier. Therefore, engineers need to test after completing the pre-design, so it is very important to proof the PCB circuit board.
PCB circuit board proofing generally refers to electronic products after the design of the engineer is sent to the PCB manufacturer to process the circuit board for trial production. Newly developed a new product, many functions are not perfect, there are still many functions that need to be debugged, and the batch production can only be carried out after the debugging is qualified. If the debugging is not qualified, it needs to be modified and debugged again.