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由若干印制线路板叠压而成的多层印制电路板,通过金属化孔构成层间线路的互连。因它必须保证各层线路板图形的一致性和重合性。随着组装密度的提高,多层印制电路板的孔间距和焊盘面积越来越小,对金属化孔和焊盘的同心度要求也越来越高。这就须要严格控制多层板制作过程中的定位精度。而定位精度又主要取决于定位基准的形式和制取方法,各道工序的定位夹具结构及使用方法,这就是多层印制电路板系统定位的主要内容。
Multi-layer printed circuit board laminated by a number of printed circuit boards, the interconnection of the inter-layer circuits is formed by the metallized holes. Because it must ensure that all layers of circuit board graphics consistency and coincidence. With the increase of assembly density, multi-layer printed circuit board hole spacing and pad area become smaller and smaller, the metal hole and pad concentricity requirements are getting higher and higher. This requires strict control of the positioning accuracy of the production process. The positioning accuracy and mainly depends on the positioning of the form and preparation methods, positioning procedures for each fixture structure and use, which is the main content of multi-layer printed circuit board system positioning.