Shielding and earthing structure of flexible circuit board

Abstract

The invention discloses a shielding and grounding structure of a flexible circuit board, to realize the aim of high reliability in grounding use, stable electric performance, low cost, good firmness and good appearance effect. In order to solve the technical problem, the invention adopts the following technical proposal: a shielding and grounding structure of a flexible circuit board includes a main board of the flexible circuit board, the main board is compounded with a grounding copper sheet through a high temperature glue film, the grounding copper sheet forms the grounding structure after gold melting and pointing tin, and the appointed position of the main board is pressed with a conductive shielding film. Compared with the prior art, if the conductive resistance is within 1 ohm, the shielding connection effect can be improved effectively, the static electricity can be conducted out in time, thus avoiding burning out other parts to influence the use, and enhancing the reliability and the electric performance of the product greatly.

Description

technical field [0001] The invention relates to a shielding and grounding structure of a flexible circuit board, in particular to a shielding and grounding structure of a flexible circuit board applied to mobile phone communications or products with high-frequency data transmission. Background technique [0002] At present, the shielding materials and processes of Flexible Printed Circuit (FPC) in domestic circuit board factories mostly adopt the structural method of silver paste printing and outer layer lamination of single-sided copper-clad foil. The silver paste used in the first method of printing silver paste is a kind of conductive liquid, which is prepared according to a certain ratio with the curing agent. The slurry contact conducts to ground. At the same time, a layer of yellow insulating ink is printed at a certain position to complete the shielding process and use effect. The second way is to laminate the outer layer with single-sided copper-clad foil. The sing...

AI Technical Summary

Problems solved by technology

[0005] Technical defects: the process is long, the process control is cumbersome and the difficulty increases and the cost is high, specifically: ①The uniformity of ink debugging directly affects the printing quality; ②The effect of ink thickness control and use; ③The drying temperature directly affects the ink after curing Flexibility and chromatic aberration; ④ The electrical properties cannot be guaranteed stably, the on-resistance is generally above 5 ohms (the best control is within 1 ohm), and the shielding effect is not ideal, etc.

[0007] Technical defects: equivalent to single-layer circuit production, the process is long and unstable, such as: ① increase the number of layers and product thickness, reduce the three-dimensional space; cause friction with the supporting structure, and reduce the service life; ② low manual efficiency , increasing the difficulty of alignment, easy to deviate, higher cost, etc.

[0008] In summary, the above two structural methods have the problems of high cost, high failure rate, and poor protection of shielding effect, which are not compatible with the low cost and high reliability of products required by the market

Images