A method of making conductive patterns on metal foil-clad insulating substrates

Abstract

The invention relates to a method for making electric conduction patterns on a metal-foil-clad insulating substrate. The method comprises the steps that insulating envelope grooves are machined in the periphery of a conducting layer which needs to be reserved, and machining is conducted twice or more when excessively narrow isolated wires are encountered; a conducting layer which needs to be removed is subdivided into a plurality of strip-shaped heat-insulating small blocks, wherein one end of each small block is narrowed, the other end of each small block is widened, and the narrowed end of one metal foil layer small block and the widened end of another metal foil layer small block adjacent to the metal foil layer small block are arranged in a corresponding mode; next, laser beams are projected onto the heat-insulating small blocks obtained after subdivision, so that the small blocks are separated from the substrate material and removed. According to the method for making the electric conduction patterns on the metal foil-clad insulating substrate, by means of adjusting the projection parameters, a projection path and the projection environment of a laser, the conducting layer on the substrate material is removed, a predetermined electric conduction structure is formed, corresponding technological processes adopted for manufacturing the electric conduction structure through a chemical method, a physical method and a laser method in the prior art are replaced, the laser is directly used for forming and making the electric conduction patterns, as a result, multiple devices and materials are omitted, environmental friendliness is achieved, the process is short, the technology is simple and easy to implement, and the method is suitable for manufacturing multiple types of circuit board samples with higher accuracy in a small-batch mode and general circuit boards.

Description

technical field [0001] The invention belongs to the technical field of circuit board processing, in particular to a method for making conductive patterns on a metal foil-clad insulating substrate. Background technique [0002] Selective removal of the conductive layer on the specified area of ​​the metal-clad substrate material is one of the key steps in the subtractive method of manufacturing circuit boards, usually by chemical etching. That is, first transfer the pattern on the surface of the copper clad laminate, cover the conductive layer of the conductive pattern part that needs to be retained, usually copper foil, with a protective material-resist, and remove the non-conductive pattern part. The copper is exposed. During etching, the etchant and the exposed metal copper contact each other and react, and the copper is dissolved into the etchant solution to achieve the purpose of removal. [0003] The etching method has a long and complicated process, and requires a lo...

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Problems solved by technology

[0026] It can be seen that the method described in DE102010019406A1 adopts a strip-shaped metal foil layer separation scheme. Since the heat dissipation conditions of each part in the middle of the small block are basically the same, and the heat dissipation conditions at the terminal end are poor, it is not conducive to the heat transfer at the high-temperature end, which further enlarges the metal foil. The temperature difference of each part of the small layer

This difference causes the temperature of the termination end of laser heating to be too high, so that it affects the adjacent wires to be retained, and the phenomenon is more prominent for those long-length strip-shaped metal foil layers.

These small pieces, because of their long length, are heavy and are not easily excluded by the airflow. In addition, the temperature of the terminal end is too high, which is more likely to affect the adjacent wires to be retained, or melt with the metal foil layer that has not been removed after falling off. Together, stay on the substrate material, affect further laser projection, and also affect the quality of the conductive structure

[0027] A further problem is that DE102010019406A1 subdivides the metal foil layer to be removed into small strips with the same width everywhere and equal width to each other. temperature, which cannot make full use of the energy delivered by the laser to the processed material, and the processing efficiency is still not high enough

On the other hand, when the strip-shaped small pieces do not reach a certain length, although the laser transmits the same amount of energy per unit time to the unit length during heating, the time and path of the laser action will also be too short to make the small pieces The temperature of the end point rises to the point where the adhesion decreases and the stress increases, causing it to fall off the substrate

[0028] The problem with this subdivision method is not only that, according to the so-called 22.5° acute angle to the main axis of the wiring, the division method of the small pieces of the separated metal foil layer with the same width and equal width will result in the middle of the metal foil layer graphics to be retained. , or between the metal foil layer and the edge, often leaving isolated small pieces that are smaller in length or width than most separated strips of metal foil layer

Such a small piece is difficult to be peeled off during subsequent heating

Obviously, the size of the isolated small pieces left by this separation method is smaller than that of the usual strip-shaped small pieces. Although the laser transmits the same amount of energy per unit time to the unit length during heating, the laser projection path is shorter, making the end point Insufficient temperature rise at the tip to cause nubs of the foil layer to detach from the substrate material

[0029] Another problem is that, according to the method described in DE102010019406A1, the compressed air plays an upward component force to remove strips of metal foil layer during processing, which plays an important role in removing the specified metal foil layer, but in practice, The wire will be burned, the surface will change color, etc.

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