一种超高精度同心环PCB的制作工艺探讨

Discussion about the super-high precision concentric ring of PCB production technology

在高能物理及核物理研究方面,会使用到一种微针结构探测器(国内简称厚GEM),其PCB加工特点是密集孔阵列设计,常规孔数多达10~50万孔,同时要求孔与隔离环的同心偏差小于5 m。对于此类超高精度同心环的加工,如采用常规工艺制作,则常因同心度超差而使得良率低下,无法达到预期的增益效果。该文即对此类超高精度同心环的PCB制作进行了可行性研究,并通过流程优化+铜箔反压+跳钻工艺+控深蚀刻技术,有效实现了镀金型厚GEM的批量生产,极大满足了客户的特种需求。

Gas Electron Multiplication (GEM) is often used in the subjects of High energy physics and Nuclear physics, in which the process feature of PCB is the design of porosity grid array with conversional hole number up to 100~500 thousands and the tolerance is no more than 5um between hole and isolation ring. Such super-high precision concentric ring made by conversional process may cause poor quality because of too poor concentricity, and can not reach the satisfactory gain effect. This paper discusses the feasibility of producing the PCB with super-high precision concentric ring. It effectively achieved the batch production of gold-plating thick GEM by process optimization, back copper lamination technology, jump drilling process and controlled etching technology, which greatly meets the special needs of custom.