微流控芯片注塑成型缺陷的成因与对策  

Analysis of Injection Molding Defects for Microfluidic Chip

作　　者：宋满仓[1] 刘莹[1] 祝铁丽[1] 张传赞[1] 刘军山[1] 刘冲[1] 

机构地区：[1]大连理工大学精密与特种加工教育部重点实验室,大连116023

出　　处：《机械工程学报》2011年第6期33-38,共6页Journal of Mechanical Engineering

基　　金："十一五"国家支撑计划(2006BAF04B13);国家自然科学基金(50605006)资助项目

摘　　要：微流控芯片是应用于生物、化学和生物医学等领域的芯片型微全分析系统,是一种表面具有微通道的薄壁塑件,微通道主要用于样本的分离。与热压成型相比,微流控芯片注塑成型效率更高,更适合大批量生产,但其成型质量控制更为复杂。试验发现,微通道复制不完全和表面缩痕是其主要成型缺陷,其对后续的芯片键合以及取样液体的电泳分离都会造成不利的影响。模拟与理论分析以及可视化试验表明,熔体在微通道处出现滞流现象和芯片各部分收缩方向不一致是上述缺陷产生的主要原因。利用正交试验方法进行充模试验,研究各工艺参数(模具温度、注射速度、注射压力和熔体温度等)对微通道复制度的影响。研究结果表明模具温度对提高微通道复制度起决定性作用;注射速度和熔体温度是次要因素,而注射压力相对其他因素影响力较差,但必须保持在一个较高的水平。Microfluidic chip,a kind of thin wall plastic parts with microchannels,is widely applied in biology,chemistry,and biomedicine.Compared with hot embossing,microfluidic chip injection molding is more efficient and suitable for mass production,but its quality control is much more complex.It's indicated in experiments that the incomplete replication of the microchannels and the sink mark for microfluidic chips are the chief defects to the molding.Negative influences are caused by these defects on the bonding of microfluidic chips and electrophoresis separation of the sample liquid.Computer simulation,theoretical analysis and visual test show that the stagnant flow of the melt in micro-channel and the difference of shrinking directions of the parts of chips are the main reasons for molding defects.Using the orthogonal experiment method(Taguchi method),the influence of different process parameters(mold temperature,injection rate,injection pressure and melt temperature) on the molding process for the incomplete replication is discussed.The results show that mold temperature is the decisive parameter to the replication fidelity of the microchannels,injection rate and melt temperature are the secondary factors,injection pressure is less important than the others,but a high injection pressure must be maintained.

关 键 词：微通道 微流控芯片 注塑成型 缺陷 计算机模拟 复制度 

分 类 号：TH-55[机械工程]