The so-called metalized half-hole means that after a drilling (drilling, gong groove) is drilled, and then drilled, the shape process, and finally half of the metalized hole (groove) is retained. In order to control the production of metal half-hole boards, some measures are usually taken due to process problems at the intersection of metalized half-holes and non-metalized holes. In the current saturated state of circuit board proofing factories, there are not many board factories willing and able to produce half-hole boards.
Metallized half-hole PCBs have fewer applications in various industries than PCBs. The metallized half-hole is easy to pull out the sinking copper in the hole when milling, so the scrap rate is very high.
For the inversion of the front, to prevent the quality of the product and the need to make corrections in the later process, the production process of this type of board is processed according to the following process: a drilling (drilling, gong groove----plate surface plating-- --External light imaging--Pattern plating--Drying--Semi-hole processing--Film removal, etching, and tin removal--Other processes--Shape)
The specific metallized half-holes are handled in the following way: all metallized half-hole PCB holes must be drilled in the pattern after plating, and before etching, drill a hole at the intersection of both ends of the half-hole.
1) The engineering department formulates the MI process according to the process,
2) The metal half-hole is the second-drilled half-hole drilled during the first drilling. After the image is plated, and before the etching,it must be considered whether the copper will be exposed when the gong groove is shaped, and the drilled half-hole must be moved into the unit.
3) Right hole (drill half hole): a. Finish drilling first, then turn the board over (or mirror direction); drill the left hole. b. The purpose is to reduce the pulling of the hole copper in the half hole by the drill, resulting in the lack of hole copper.
4) The size of the drill nozzle for drilling the half hole depends on the spacing of the contour line.
5) Draw the solder mask film, use the gong space as a stop point and open the window to increase 4mil treatment.
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