Production method of stepped groove circuit board with through hole, soldermask and circuit graphics at groove bottom

Abstract

The invention relates to a production method of a stepped groove circuit board with a through hole, a soldermask and a circuit graphics at a groove bottom, which comprises the following steps that: 1, a sub board is produced, and is provided with the circuit graphics, the soldermask and the metalized through hole; 2, a prepreg and a core board are provided, and a through groove is arranged at the prepreg; 3, packing is carried out, a polytetrafluoroethylene (PTFE) gasket is placed in the through groove, and a polyimide adhesive tape is adhered to one side of the PTFE gasket, which is close to the sub board; 4, lamination is carried out, so a mother board is produced; 5, the through hole is drilled on the mother board, a protective adhesive tape is adhered to the outer end of the metalized through hole, and then copper deposition and electroplating are carried out; 6, the protective adhesive tape is removed, and an outer layer of circuit graphics is produced; 7, the outer layer is subjected to soldermask treatment, the board is milled in a depth control way, and a stepped groove is formed; and 8, the PTFE gasket and the polyimide adhesive tape are taken out, surface treatment is carried out, so the stepped groove circuit board is produced. According to the production method, the stepped groove circuit board of which the through hole at the groove bottom cannot be blocked can be produced, and the soldermask of the groove bottom is good.

Description

technical field [0001] The invention relates to the field of circuit board production, in particular to a method for producing a stepped groove circuit board with through holes at the bottom of the groove, solder resist and circuit patterns. Background technique [0002] For stepped groove circuit boards with circuit patterns, through holes and surface treatment at the bottom of the groove, at present, gaskets are embedded in the groove to resist glue, the circuit pattern and surface treatment of the bottom of the groove are pre-made, and the through holes are plugged. And then can't make for the through hole at the bottom of the groove that can't plug hole (as plug hole). At the same time, there is a problem that the solder resist at the bottom of the groove is easy to peel off during lamination under high temperature and high pressure. In addition, in traditional production methods, silicone sheets are often used for the embedded gaskets. Because there are gaps inside the...

AI Technical Summary

Problems solved by technology

And for the through hole at the bottom of the groove that cannot be plugged (such as a plug hole), it cannot be made

At the same time, there is a problem that the solder mask at the bottom of the groove is easy to peel off during lamination under high temperature and pressure

In addition, the embedded gaskets in the traditional production method often use silica gel sheets. Due to the gaps inside the silica gel sheets, the residual water vapor expands under high temperature and high pressure, resulting in bubbling and cracking of the laminated prepreg.

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