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使用无引线陶瓷芯片载体(LCCC)可以达到高密度封装。普通印制板(PWB)对于无引线陶瓷芯片载体不是满意的基板,因为热膨胀系数(TCE)不匹配能引起铅焊处开裂。解决这个问题的一个方法是把铜一殷钢—铜(CIC)粘到印制板上。铜—殷钢—铜减小了印制板的热膨胀系数,使它与陶瓷的热膨胀系数相匹配。除了起抑制膨胀作用外,铜—殷钢—铜也被用作电源板,或接地板,以及散热片。这个课题的任务是研制具有铜—殷钢—铜结构的多层印制板的生产工艺,支持洛克希德火箭和航天公司(LMSC)的计划。多层板具有以下生产特点:铜—殷钢—铜来自两个供应商,铜—殷钢—铜预先钻孔,聚酰亚胺和环氧树脂作为介质。铜—殷钢—铜或与金属化孔绝缘或与金属化孔(PTH)互联,铜—殷钢—铜表面处理或由生产厂家处理或由用户自己处理。还有,为了暴露出铜—殷钢—铜以便与热传导体接触,使用二氧化碳激光器把绝缘材料从印制板边缘除去。印制板试样必须经过MIL—P—55110标准浮焊试验,然后对金属化孔进行剖视。金相切片实验显示铜—殷钢—铜有良好的内层附着力以及对预钻孔有良好的树脂填充能力。殷钢在化学沉铜线中受化学物质腐蚀引起凹蚀。除了观察到殷钢界面有一些空隙外,铜—殷钢—铜的电镀附着力一般是合格的。改进后的工艺可以减少空隙数量。
High-density packaging is achieved using a leadless ceramic chip carrier (LCCC). Common Printed Boards (PWBs) are not satisfactory substrates for leadless ceramic chip carriers because mismatch in coefficient of thermal expansion (TCE) can cause cracking in the lead welds. One way to solve this problem is to stick copper-Invar-Copper (CIC) to the printed board. Copper - Invar - Copper reduces the coefficient of thermal expansion of the printed board to match the coefficient of thermal expansion of the ceramic. In addition to suppressing expansion, copper-invar-copper is also used as a power board, or ground plane, and heat sink. The task of this task was to develop the production of multilayer PCBs with copper-Invar-Cu structures and support the Lockheed Rocket and Space Project (LMSC) program. Multilayer PCB has the following manufacturing features: Copper - Invar - Copper from two suppliers, copper - Invar - copper pre-drilled, polyimide and epoxy as media. Copper - Invar - Copper or insulated with metallized holes or interconnected with metallized holes (PTH), Copper-Invar - Copper Surface treated either by the manufacturer or disposed by the user. Also, in order to expose the copper-invar-copper to contact with the heat conductor, a carbon dioxide laser is used to remove the insulating material from the edge of the board. Printed board samples must pass MIL-P-55110 standard float welding test, and then cross-sectional view of the metalized holes. Metallographic sectioning experiments show that copper-invar-copper has good inner-layer adhesion and good resin-filling ability for pre-drilled holes. Invar chemical corrosion in chemical immersion copper lines caused by corrosion. In addition to the observed Invar interface with some gaps, the copper - invar - copper plating adhesion is generally qualified. The improved process can reduce the number of voids.