Abstract: In order to meet the requirements of high bonding uniformity and high bonding precision in the ultrasonic bonding processes for POCT chips, an ultrasonic bonding pressure adaptive balancing device was designed by using the characteristics of air with low frictional resistance and elastic compressibility, and the principle of bonding pressure adaptive balancing was analyzed. To verify the bonding effects of the devices, several pressure distribution uniformity experiments, bonding experiments, and comparison tests of resonance frequency and impedance for ultrasonic vibrators were carried out. The results show that the devices may control the peak-to-peak value of micro-channel height within 1.3 μm and the peak-to-peak value of fusion line width within 23.3 μm for chips with the size of 69 mm×15 mm. Compared with the control group, the devices may reduce the pressure distribution uniformity coefficient by about 50%~72%, reduce the peak-to-peak value of micro-channel height by 96.2% and the standard deviation by 96.8%, reduce the peak-to-peak value of fusion line width by 96.8% and the standard deviation by 96.3%. The devices have good adaptability to the chips with a length in range of 19~69 mm, and the peak-to-peak value of micro-channel height may be controlled within 1.9 μm. The devices do not have a large impact on the ultrasonic vibrator systems of the original bonding equipment. And at the same bonding pressure compared to the stainless steel fixture, the maximum difference in resonant frequency and anti-resonant frequency is as 2 Hz, and the difference in minimum and maximum impedance values do not exceed 3.5%. The ultrasonic bonding pressure adaptive balancing devices have good pressure adaptive balancing capability, which may effectively improve bond uniformity and bonding accuracy to meet the requirements of POCT chips for high bond uniformity and high bonding accuracy.

Key words: point-of-care testing(POCT) chip, ultrasonic bonding, adaptive pressure balancing, bonding uniformity, bonding accuracy

摘要： 针对即时检测芯片在超声波键合过程中对高键合均匀性和高键合精度的要求，利用空气具有摩擦阻力小和可弹性压缩的特点，设计了超声波键合压力自适应平衡装置，分析了键合压力自适应平衡原理。为验证该装置的键合效果，开展了压力分布均匀性实验、键合实验、超声振子谐振频率和阻抗的对比。结果表明：对于69 mm×15 mm的芯片，该装置能够将微通道高度峰峰值控制在1.3 μm以下，将熔接线宽度峰峰值控制在为23.3 μm以下；相比对照组，该装置能够降低压力分布均匀性系数约50%~72%，能够将微通道高度峰峰值减小96.2%，标准差减小96.8%，能够将熔接线宽度峰峰值减小96.8%，标准差减小96.3%；该装置对长度为19~69 mm的芯片具有较好的适应性，微通道高度峰峰值能够控制在1.9 μm以下；该装置不会对原有键合设备的超声振子系统产生较大影响，在相同键合压力下对比不锈钢夹具，谐振频率的最大差值和反谐振频率的最大差值均为2 Hz，最小阻抗模值和最大阻抗模值的差值均不超过3.5%。超声波键合压力自适应平衡装置具有较好的压力自适应平衡能力，能够有效提高键合均匀性和键合精度，满足即时检测芯片对高键合均匀性和高键合精度的要求。

关键词: 即时检测芯片, 超声波键合, 自适应压力平衡, 键合均匀性, 键合精度