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问与答

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问与答

一.   TP Shift issue about LCM with resistive touch panel

1.    Case: TF17713A/26010A and other projects

2.    Q  : TP move toward the sealing direction and tilt upwards in the fpc direction

3.    ReasonThe FPC of TP has strong thrust when bending, the double-sided adhesive on the tp weakens after long time stress and affected by the environment, resulting in tp shift beyond the backlight edge

4.     Answer
*   The backlight should be as wide as possible so that the tp sinks into the frame to prevent the TP shift

*   Increase the lower iron frame and design the iron frame ear elevation to prevent the tp shift

*   Increase the stickiness and paste area of the double-sided adhesive tape (the width of the back edge be as wide as possible)

*   Add 0.05mm yellow tape to the backlight in tp's fpc direction


5.   Storage: under normal temperature

6.   Try to put on production within 1-5 months after producing and shipping




二. The design of  LCM plus plastic frame 


1.      Case :TF3906B/TF39708A/17714A/28029B

2.       Q :FOG stressed and separated from black light, leading to light leakage

3.       ReasonsA large size fpc has a relatively large bending force, which reduces the adhesive area. When the bracket is assembled on the main board, the bracket is deformed due to the tight buckling, thereby the backlight stressed and the fog pulled up.

4.      Answer

*   Shorten the folded neck on the double-sided adhesive of fpc in order to lower the lifted fog.

*   The bracket registration mast fits too tightly with pcb hole, resulting in support extrusion.

*   Projects of 2.8 or more inches need open the upper iron frame to press lcd.

*   Try not to design fpc to bend after modules in that customers use it in a high temperature