FPC flexible circuit board production process and process requirements

FPC flexible circuit board production process and process requirements

Printed circuit board,, the beginning is cardboard (old radio), now generally FR4 rigid board, there are some special plates, today to introduce the flexible circuit board (Flexible Printed Circuit abbreviated as FPC) is made of polyimide or polyester film as the substrate of a highly reliable, excellent flexible printed circuit board. It has the characteristics of high wiring density, light weight, thin thickness and good bendability. Mainly used in cell phones, notebook computers or LCD screens and other thin and light electronic products.

The core layer of flexible circuit board is an ultra-thin polymer film.
First, the polymer film will be sandwiched between two copper sheets by the machine. On the machine first uniformly cut into rectangular sheets, after the laminate is isolated and put into a pile.
Secondly, it is sent into the vacuum pump box to closely absorb the layers together, and then sent into the high temperature and pressure box for several hours, because the middle layer of the polymer film itself has a heat activated adhesive coating, so that the original 3 layers will be bonded into a whole, the pile of laminates will be cut into fixed size boards and drilled with small holes to facilitate assembly, and then the fourth layer of photographic layer film is glued on the surface of the circuit board by the adding machine.

Third, the technician uses the computer to draw the IC diagram according to the customer's needs, and then puts the board into the exposure machine, the computer will control the machine to laser scan the photosensitive layer. The surface of the irradiated photographic layer will react and harden so that the copper layer underneath will be protected from acid washing.

Fourth, after cleaning the area not irradiated by the laser with the acid washing machine, the copper layer left on the entire polymer film is the original computer-drawn integrated circuit. Then use the sticky dust roller to remove the surface dust, and then put on the fifth layer of insulation.

Fifth, the entire circuit board, with plastic paper and laminate isolated into a pile, again sent into the vacuum pump box will be tightly sucked together the layers, and then sent into the high temperature and high pressure box for several hours.

Sixth, wait until the circuit board cools down, you can manually put into the mold, using a stamping machine to make the specified shape, a flexible circuit board is officially completed!