285results about How to "High precision forming" patented technology

A method for forming a throughhole in an ink-jet print head of a bubble-jet system includes the steps of: forming a bubble-generator which is adjacent to a throughhole-forming region on one side of a substrate, and which includes a heater; forming a first mask layer for covering portions excluding the throughhole-forming region on a first side of the substrate; forming a second mask layer for covering portions excluding the throughhole-forming region on a second side of the substrate; forming a first well with a predetermined depth on the throughhole-forming region of the substrate not covered by the first mask layer by spraying sand under high pressure and at a high speed onto the first side of the substrate; forming a second well corresponding to the first well on the throughhole-forming region of the substrate not covered by the second mask layer by spraying sand under high pressure and at a high speed onto the second side of the substrate; forming a throughhole by overlap of the first well and the second well on the throughhole-forming region; and removing the first and second mask layers. Accordingly, a plurality of throughholes can be formed on a plurality of substrates at one time, and the time required for processing throughholes on one wafer can be reduced considerably compared to prior techniques, thereby promoting mass production. Furthermore, the size of the nozzle for spraying the sand, and consequently the size of the throughhole, is uniform and does not change. The size of the throughhole is determined by the mask layers, thereby forming a throughhole having a very uniform size with high precision.