AlSiC电子封装复合材料磨削用钎焊金刚石微刃砂轮的研究

Due to the high thermal conductivity and adjustable CTE, AlSiC composite material is replacing conventional alloys as a novel electronic packaging material.However,in the grinding of AlSiC composite material the conventional grinding wheel's bond is worn severely， which cause the dislodging of diamond grits and the worse surface integrity. So we propose a study on fabrication of the brazed diamond grinding wheel with micro-array of protrusion for grinding AlSiC electronic packaging composite material.Higher,even and uniform diamond protrusions can be achieved to reduce the grinding forces and to increase the wear resistance of the bond of grinding wheel by investigating the orderly patterning of diamond grits and the mechanisms of the flat-top brazing of coarse diamond grits with well crystal structure. By the study of the fundamental of micro-machining of diamond grit by the pulse-Laser and the techniques of controlling the geometric parameters of micro-array of protrusions, the dimension and the angle of the protrusions can be controlled to increase the wheel'sharpness and to reduce the surface stress of AlSiC for a better surface integrity. The grinding mechanism of AlSiC composite materials, the wear and failure of the grinding wheel will be studied. The effect of the ordered patterns of diamond grits and the geometric parameters of the protrusions on the grinding performance, surface integrity and the grinding wheel's wear and failure will also be investigated. Finally the technlogies of fabricating the brazed diamond grinding wheel for AlSiC electronic packaging composite materials can be obtained.

由于具有高导热率和可调的热膨胀系数，AlSiC复合材料逐渐取代传统材料成为新型电子封装材料。但是传统的金刚石砂轮磨削AlSiC复合材料时结合剂磨损严重，金刚石磨粒易脱落，加工表面完整性低。本项目针对高SiC体积分数的AlSiC电子封装复合材料提出了一种新型钎焊金刚石微刃砂轮的制造方法。通过金刚石磨粒有序排布结构优化、粗粒度完整晶型金刚石的平顶化钎焊机制与工艺研究，获得足够高、均匀和一致性的出刃，有效降低磨削力，提高结合剂抗磨损能力；通过脉冲激光对钎焊金刚石的微结构刻蚀机理与工艺研究，制备尺寸和角度可控的微结构磨削刃，提高砂轮对AlSiC复合材料磨削的锋利度，降低复合材料磨削表面应力，提高表面完整性；研究砂轮的磨削机理、磨损和失效机理，掌握磨粒有序排布结构、微结构磨削刃几何参数对砂轮的磨削性能、磨削表面完整性、磨损和失效的影响规律，获得AlSiC电子封装复合材料磨削用金刚石砂轮的制造技术。

钎焊金刚石砂轮拥有磨粒结合强度高、出刃高、容屑空间大、磨削锋利的特点，但由于细粒度金刚石的钎焊存在很大的难点，因而在精密磨削领域还很少使用钎焊金刚石砂轮。本研究提出了一种钎焊金刚石微刃砂轮的制备方法，即使用激光微细加工的方法在有序钎焊完整晶型金刚石砂轮的表面进行刻蚀，制备即具有粗粒度钎焊金刚石的高结合剂强度和出刃，又具有细粒度金刚石砂轮的微细磨刃，从而获得一种精密磨削用钎焊金刚石微刃砂轮的制造技术。.首先使用粗粒度完整晶型金刚石磨粒进行平顶化钎焊，研究了完整晶型金刚石钎焊平顶化规律；再使用脉冲激光对金刚石磨粒进行微刃刻蚀，研究了脉冲激光对钎焊金刚石磨粒的微刻蚀机理研究，通过仿真和实验分析，研究了脉冲绿激光加工金刚石的烧蚀阈值。研究了光纤激光在完整晶型金刚石及CVD金刚石上刻蚀微沟槽过程中的工艺规律，分析激光微细加工的沟槽宽度、深度与激光加工参数（脉宽，扫描速度，扫描次数等）的关系。分别使用单颗粒钎焊金刚石工具、单层钎焊金刚石磨具、单层钎焊金刚石微结构磨削刃工具加工AlSiC复合材料，研究了不同工具加工不同SiC体积分数的AlSiC复合材料中的磨削机理；研究钎焊金刚石微刃工具加工不同SiC体积分数的AlSiC复合材料过程中的材料表面去除机制、表面完整性，并对单层钎焊金刚石微刃砂轮的磨损和失效机制进行了分析。.结果表明：粗粒度完整晶型钎焊金刚石可以有效实现平顶化钎焊，脉冲激光可以有效控制金刚石微刃的密度和尺寸，钎焊金刚石微刃砂轮在磨削AlSiC复合材料时可以通过沿激光刻蚀沟槽以微刃的微破碎的形式，提高砂轮的自锐性，降低砂轮的磨削力。