How to solve the difficult problems of industrial PCBA

[Linlin]

1. Heat dissipation problem

Problem Description:

Industrial control PCBA products have a large workload and heat production. Thermal design has a great influence on product performance

The heat dissipation design of industrial PCBA starts from the choice of heat dissipation method and the choice of components. The cooling method determines what components are used and affects the assembly design, reliability, quality and cost of PCBA products

solution:

The temperature of the component or equipment depends on its heating capacity, structural dimensions related to heat dissipation, working environment and other special requirements (such as sealing, air pressure, etc.)

When choosing the cooling RC JET method, it should be coordinated with the electronic circuit simulation test to carry out synchronous research to meet the requirements of electrical performance and thermal reliability index; volume power density, heat flux density, volume, total power consumption, working thermal environment and other equipment (or components) ) The state, surface area, radiator and other special conditions should also be fully considered

2. Connector problem

Problem description:

There are three main failure modes of the connector: electrical contact failure, insulation failure and mechanical connection failure. The failure mode of the electrical contact is that the contact resistance increases and the contact pair is disconnected instantaneously; usually the CCUR in the crimped joint or the welded (cup-shaped) joint

solution:

The main reasons for this phenomenon are:

1) After the wire is tinned and crimped, the contact area between the wire and the contact is reduced, resulting in an increase in contact resistance

2) The snap ring of the crimping joint fails or the contact is not installed properly, which causes the contact to be unlocked, resulting in a reduced contact area or no contact

3) The cause of the failure of the welding (cup) electrical contact is generally a broken wire or a damaged core. This phenomenon is mainly due to the damage of the wire core caused by the stress on the wire solder joints or the wire peeling off. In addition, most of the solder joints are wrapped with heat-shrinkable tubing. After the casing is shrunk, it is not easy to find even the wire is damaged, and the solder joints are connected and broken during the vibration of the equipment

4) This is a contact problem caused by contact size or wear