研究了细胞培养器微注塑模具型腔的制作方法。针对微注塑模具型腔的结构特点, 采用UV-LIGA套刻技术, 分别通过两次SU-8胶光刻和Ni的微细电铸制作了以合金钢为基底的微结构; 然后利用掩膜腐蚀方法在铸层上腐蚀出微排气通道。对SU-8厚胶工艺过程中的溶胀现象、匀胶不平整和去除困难等问题进行分析, 提出在掩膜板图形四周增设封闭的宽度为20 μm的隔离带来减少图形四周SU-8厚胶体积, 改善了该处胶模的热溶胀变形, 使铸层的尺寸误差由原来的35 μm降低到10 μm, 300 μm高的微柱体侧壁陡直。隔离带的引入有效地提高了铸层图形的尺寸和形状精度。由于采用了刮胶的匀胶工艺和发烟硫酸去除SU-8胶的方法, 消除了“边缘水珠效应”, 彻底去除了SU-8胶。采用提出的方法可获得铸层质量好, 与基底结合强度高的微注塑模具型腔。

A fabrication method of micro-injection mold cavity for a cell culture device was explored in this paper. Based on the structural characteristics of the micro-injection mold cavity and overlay UV-LIGA technology, a microstructure using appropriate alloy steel as the substrate was fabricated through SU-8 photoresist optical lithography and micro-electroforming technology respectively twice. Then, a micro exhaust duct was etched on an electroforming deposit through mask etching technology. Meanwhile, the swelling problem of SU-8 thick photoresist, poor surface evenness through spin-coating and SU-8 photoresist removal in the experiment process were analyzed, and a method of designing and fabricating a 20 μm wide closed isolation strip around the mask graphics was presented to reduce the volume of SU-8 thick photoresist around the graphics and to improve the swelling deformation of plating mold. By which, the dimension error of the electroforming deposit is from 35 μm down to 10 μm and 300 μm high micro-square-cylinder side wall is steep. The introduction of closed isolation strip improves the dimensional and shape precisions of nickel electroforming deposit effectively and the uses of scraping photoresist and oleum techniques eliminates the edge bead effect and removes SU-8 photoresist completely. As a result, the micro-injection mold cavity with good quality and the high bonding strength between substrate and nickel electroforming deposit is obtained successfully.