Method for manufacturing flexible circuit board

Abstract

A method for manufacturing a flexible circuit board includes the following steps: providing a paste comprising a photocurable elastic resin, a carbonization precursor, and a metal catalyst; 3D printing and curing the paste to form a printed component; irradiating a portion of the printed component with a laser, wherein the carbonization precursor in the irradiated area forms a carbonization layer, and the metal catalyst in the irradiated area is reduced to a metallic element; and placing the printed component with the carbonization layer in a metal salt solution for reaction, wherein metal ions in the metal salt solution are replaced by the metallic element and deposited on the surface of the carbonization layer to form conductive lines. The flexible circuit board manufacturing method provided in this application has a simplified process, lower cost, higher precision, and can manufacture irregularly shaped flexible circuit boards.

Claims

1. A method for manufacturing a flexible circuit board, the improvement of which includes the following steps: providing a slurry, the slurry comprising a photocurable elastic resin, a carbonization precursor, a metal catalyst, and a conductive filler, wherein the conductive filler is a carbon nanotube or carbon fiber, the conductive filler having a content of 0.5% to 15% by weight in the slurry, and the metal catalyst being selected from a salt compound of at least one metal selected from silver, copper, nickel, palladium, or rhodium, the metal catalyst having a content of 0.01% to 5% by weight in the slurry; 3D printing the slurry and then curing it to form a printed part; laser irradiating a portion of the printed part, wherein the carbonization precursor in the laser-irradiated area forms a carbonization layer, and the metal catalyst in the laser-irradiated area is reduced to a metal element; and placing the printed part forming the carbonization layer in a metal salt solution for reaction, wherein metal ions in the metal salt solution are replaced by the metal element and deposited on the surface of the carbonization layer to form conductive lines.

2. The method for manufacturing a flexible circuit board as described in claim 1, wherein, The photocurable elastic resin is a polyurethane acrylate or a silicone acrylate.

3. The method for manufacturing a flexible circuit board as described in claim 1, wherein, The laser has a wavelength of 350nm~450nm, a laser irradiation power of 1W~10W, and a laser energy density of 100J / cm2~200J / cm2.

4. The method for manufacturing a flexible circuit board as described in claim 1, wherein, The metal salt solution contains copper sulfate or nickel sulfate, and the pH of the metal salt solution is 9-13.

5. The method for manufacturing a flexible circuit board as described in claim 4, wherein, The temperature at which the printed parts are reacted in the metal salt solution is 40°C to 60°C.

6. The method for manufacturing a flexible circuit board as described in claim 4, wherein, The metal salt solution also contains at least one of potassium chloride, anhydrous sodium pyrophosphate, and ammonium sulfate.

7. A method for manufacturing a flexible circuit board as described in claim 1, wherein, The carbonization precursor is an aromatic compound or a phenolic compound.

8. A method for manufacturing a flexible circuit board as described in claim 1, wherein, Before placing the printhead in the metal salt solution, the printhead, after being treated with laser irradiation, is placed in a cleaning solution for cleaning. The cleaning solution contains sulfuric acid and hydrogen peroxide in a volume ratio of 1:

1. The cleaning solution is used to remove impurities remaining on the surface of the printhead and to activate the carbonized layer so that functional groups are formed on the surface of the carbonized layer. Then, the printhead is cleaned with deionized water.

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