Flexible Printed Circuit Board Applications (2)

4. FPC process

4.1. General process

4.2. Drilling NC Drilling
The double-sided panel is drilled in order to make the upper and lower wires conduct through the plated through hole for subsequent copper plating.

4.2.1. Drilling program code

Copper foil drilling procedure

B40 NNN RR 400(300)
Copper foil base material number code format at the end of three yards (4000/3000)

Overlay drilling procedure

B45 NNN RR 40T (30B)
Cover Film Item Number Last Three Code Version 40/30 Program Format
T on CVL B CVL

Reinforcement drilling program

B46 NNN RR 4#A
Strengthen the piece number of the last 3 code version 4 program format
# Direction of release paper
0-no, 1-up, 2-down, 3-sided
A Reinforcement A

Adhesive drilling procedure

B47 NNN RR 4#A
Latex Item Number Last 3 Code Version 4 Program Format
# Direction of release paper
0-no, 1-up, 2-down, 3-sided
A Reinforcement A

4.2.2. Drilling program layout

Alignment hole: Located in the four corners of the layout where the lower left corner is 2 holes (direction hole) The remaining 3 corners are 1 hole total of 5. The five holes used for hole drilling are also used for exposure and AOI pin holes and direction identification.

Broken needle inspection hole: Located above the direction hole in the lower left corner, it is the last hole drilled by each hole drill. When a broken needle causes missed drilling, the hole of the hole will be reduced.

Examining hole: In the middle of the board, the first 1.0mm hole was drilled to make a test piece, and then four holes were drilled inside the plate with the minimum hole diameter of the part number as the slicing inspection after copper plating.

4.2.3. Drilling considerations

Thickness of Masonry Board (Boiling Plate 0.8mm, 1.5mm) Size
Board direction Pin direction
Number of boards
Drilling program file name version
Drill life
The alignment hole must be in the plate
Broken needle check

4.3. Black Hole/Copper Plating Black Hole/Cu Plating

After drilling, black holes are used in the insulation position of the hole wall to adhere to the carbon powder to conduct electricity, and then the hole copper is formed on the hole wall by means of copper plating to reach the upper and lower lines. The general approach is to first make the hole wall with a positive charge through the black hole, so that the carbon particles with negative particles adhere to the surface, and then micro-etch the carbon powder on the copper surface peel, leaving only the hole wall insulation position A layer of carbon powder is copper plated to form copper.

4.3.1. Black Hole Considerations

Micro-etching is clean without roller mark water crease
4.3.2. Copper Plating Precautions

Whether clamping plate is clamped
Copper-plated copper thickness
Hole copper biopsy can not be broken


(to be continued)