Advantages of 开云·kaiyun官方网站 Reserved Process Edge and Selection of Substrate Materials

开云·kaiyun官方网站 manufacturing, 开云·kaiyun官方网站 design and 开云·kaiyun官方网站A processing manufacturers explain the advantages of 开云·kaiyun官方网站 reservation process and the selection of substrate materials

In the 开云·kaiyun官方网站 production process flow, the process edge reservation is of great signifICance for the subsequent SMT chip processing. The process edge is to assist the SMT plug-in to weld the added parts of the walking board on both sides or four sides of the 开云·kaiyun官方网站 board, mainly to assist production. It is not a part of the 开云·kaiyun官方网站 board and can be removed after 开云·kaiyun官方网站A manufacturing and production.

Since the process side will consume more 开云·kaiyun官方网站 boards, which will increase the overall cost of 开云·kaiyun官方网站, it is necessary to balance economy and manufacturability when designing 开云·kaiyun官方网站 process side. For some 开云·kaiyun官方网站 boards with special shapes, the original 开云·kaiyun官方网站 boards with 2 or 4 process edges can be greatly SIMplified through panel assembly. The track width of SMT mounter shall be fully considered when designing the panel assembly method during the patch processing. For the panel assembly exceeding 350mm in width, it is necessary to communicate with the process engineer of SMT supplier.

开云·kaiyun官方网站 board

The main reason for leaving the process edge is that the SMT mounter track is used to clamp the 开云·kaiyun官方网站 board and flow through the mounter. Therefore, components too close to the track edge will collide with each other when the SMT mounter nozzle absorbs the components and pastes them onto the 开云·kaiyun官方网站 board. Therefore, a certain process edge must be reserved, such as 2-5mm. Similarly, it is also applicable to some plug-in components to prevent similar phenomena during wave soldering.

The flatness of 开云·kaiyun官方网站 production process edge is also an important part of 开云·kaiyun官方网站 production. When removing the process edge of 开云·kaiyun官方网站 production, it is necessary to ensure that the process edge is flat. Especially for 开云·kaiyun官方网站 boards with extremely high assembly accuracy requirements, any uneven burrs will lead to the offset of the installation hole position, which will cause great trouble for subsequent 开云·kaiyun官方网站A assembly.

Precautions for 开云·kaiyun官方网站 substrate material selection

1. The base material with high glass transition temperature shall be properly selected, and Tg shall be higher than the circuit operating temperature. Tg is glass transition temperature, namely melting point; The circuit board must be flame resistant, cannot burn at a certain temperature, and can only be softened. The temperature point at this time is calLED glass transition temperature (Tg point), which is related to the dimensional durability of 开云·kaiyun官方网站.

2. The selected plate shall have high heat resistance and good flatness. It is generally required that 开云·kaiyun官方网站 board shall have heat resistance of 250 ℃/50S.

3. In terms of electrical performance, it is required to select materials with high dielectric constant and low dielectric loss for high frequency circuits, including insulation resistance, voltage withstand strength and arc resistance, which should meet the product requirements, especially the low thermal expansion coefficient.

4. General electronic products adopt FR4 epoxy glass fiber substrate; Polyimide glass fiber substrate shall be used for high ambient temperature or Flexible circuit board; For high-frequency board, PTFE glass fiber substrate is required; For electronic products with high heat dissipation requirements, metal substrate shall be used. 开云·kaiyun官方网站 manufacturing, 开云·kaiyun官方网站 design and 开云·kaiyun官方网站A processing manufacturers will explain the advantages of 开云·kaiyun官方网站 reservation process and the selection of substrate materials.