4.8x4.8x0.55mm Micro Tactile Push Button Switch Membrane Tactile patch 4 Pin delamination

1.In the application of new energy intelligent automobile equipment remote controllers, the 4.8x4.8x0.55mm Micro Tactile Push Button Switch is used.

During the usage, customers have reported membrane detachment issues with the 4.84.80.55mm membrane switch. Upon inspection of the defective units sent in, it is observed that there is misalignment and detachment of the dome and buttons from the membrane.

2.Analyzing the defects shown in the provided images, the likely cause of customer complaints could be attributed to abnormal usage conditions. Under normal circumstances, such issues wouldn't occur during regular operation unless there's external force or exposure to liquid.

3.Observing the condition of the received products, it is noted that the boards used by your company are double-sided. This product should have undergone two reflows and then been soldered with connectors through post-soldering. It's evident that there is significant rosin residue along the edges of the membrane switch. This can be attributed to excessive soldering during post-soldering, resulting in heat damage to the membrane switch. The rosin and smoke directly enter the cover film of the membrane button, causing the adhesive strength of the glue to weaken over time. Consequently, the membrane switch's base and dome film separate, leading to malfunctioning buttons.

4.The most direct improvement method for the post-soldering process would be to use fixtures or jigs to protect the membrane switch before post-soldering.

5.Another solution could involve replacing the cover film on this membrane switch with a covered version (4.8*4.8*1.0mm) or switching to membrane switches with high-temperature resistant PI cover films instead of adhesive-covered dome switches. However, both options would require structural modifications.