PCB Fabrication

The hazards and treatment measures of PCB circuit board deformation

by:A-TECH      2021-03-10
According to incomplete statistics, in 2018 alone, the scale of domestic PCB output value reached a dominant position of tens of billions, and the domestic PCB industry has become more and more mature and continues to extend to the mid-to-high-end market. In recent years, the complexity of PCB layout design is significantly higher than in the past. In order to manufacture smaller and more portable electronic devices, the density and quality of the design must continue to increase. In addition to ensuring the quality of the PCB board during PCB processing, the PCB factory will inevitably encounter distortions during the PCB board processing. The reasons are very complex. The reasons for the deformation of the PCB board processing are very complex and diverse. It can be divided into thermal stress and mechanical stress caused by two kinds of stress. Among them, the thermal stress is mainly generated during the pressing process, and the mechanical stress is mainly generated during the accumulation, transportation and baking process. If the quality of the plate used is not up to standard and the distribution of the copper skin is not uniform, it will cause warping and deformation after pressing. There are many reasons for this. Here I will only list some of the reasons for your reference. How to judge a qualified PCB circuit board? Let's look down: 1. The shape is not deformed, so as to avoid deformation of the housing after installation and dislocation of the screw holes. Now it is all mechanized installation. The hole position of the circuit board and the deformation error of the circuit and the design should be controlled within the allowable range. 2. The line width, line thickness, and line distance of the line meet the requirements to avoid line heating, open circuit, and short circuit, etc. The problem occurs 3. The copper surface is not easy to be oxidized and does not affect the service life. 4. The mechanical properties of the surface must meet the installation requirements. 5. The copper skin is not easy to fall off under high temperature. We have just analyzed the reasons for the deformation. Next, let's take a look What are the hazards? The first is that on the placement line of the input equipment, the overall circuit board is uneven, and the components will be misaligned, which cannot be accurately mounted on the designated pads on the surface of the circuit board, and the automatic insertion will be damaged. Install the equipment; the circuit board with the components is bent after welding, and the component feet are difficult to cut neatly. The entire circuit board cannot be installed in the specified product. Therefore, most PCB manufacturers need to go through a leveling process before shipment, and will pass a strict flatness inspection during the final inspection. It can be effectively improved by mechanical leveling or thermal bake leveling before shipment. Affected by the heat resistance of the solder mask and the surface coating, the general baking temperature is below 150℃, which just exceeds the Tg temperature of ordinary materials. This has great benefits for the leveling of ordinary boards, and the leveling effect for high Tg materials It is not so obvious, so the temperature of the baking sheet can be appropriately increased on the high Tg boards with serious board warpage, and a series of measures can be improved to reduce the defective rate of finished products. PCB has always insisted on using superb technical force, sophisticated production equipment, perfect testing methods, product quality higher than industry standards, and warm and thoughtful service, which has won praise and welcome from global merchants and users. From here, enter the pricing and order page https://www./QB. New user registration will immediately give away a 260 yuan deduction coupon, and there are more discounts waiting for you.
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