What Are The Basic Requirements Of The Wave Soldering Process For Components And Printed Boards？

1. Requirements for SMC / SMD

      The metal electrode of the components assembled on the surface pcb should choose a three-layer terminal structure. The component package and the solder end can withstand more than two times 260 ℃ ± 5 ℃, 10s ± 0.5s (lead-free requirements 270 ~ 272 ℃ / 10s ± 0.5 s) Temperature shock of wave soldering. After the smt patch is soldered, the component package is not damaged, cracked, discolored, deformed, or brittle, and the chip component ends are not peeled. At the same time, the electrical performance parameters of the component after SMT processing after wave soldering Whether the changes meet the requirements defined in the specifications.

2. Requirements for inserted components

      Using short-plug one-time soldering process, the component leads should be exposed to the PCB soldering surface 0.8 ~ 3mm.

3. Requirements for printed circuit boards

      The PCB should have heat resistance of 260 ℃ for more than 50s (lead-free 260 ℃ for more than 30min or 288 ℃ for more than 15min, 300 ℃ for more than 2min), copper foil has good peel strength, solder mask There is still sufficient adhesion at high temperature, the solder mask does not crease after welding, and there is no scorch. Generally use RF-4 epoxy glass fiber cloth printed circuit board. The warpage of PCBA printed circuit board is less than 0.8% ~ 1.0%.

4. Requirements for PCB design

      Must be designed according to the characteristics of the mounted components.

The component layout and arrangement direction should follow the principle of smaller components in front and try to avoid blocking each other.