Study On Vacuum Thermocompression Bonding System Of Polymer Microfluidic Chip

Microfluidic chip technology,as one of advanced technology,integrates traditional biological and chemical experiments into chips of several square centimeters in size.It has extremely broad application prospects in the fields of gene detection,vitro diagnosis,cell sorting,drug synthesis and screening.The reaction volume of the samples and the reagents are usually microliters or even nanoliters.In addition to ensuring the high accuracy and high efficiency of the detection,the amount of the samples and the reagentsare saved as much as possible.The hot press method is used to coin the substrate of PMMA chip,which has the advantages of simple equipment requirements,low material cost,short process cycle,high forming precision,and good industrialization.The aim of researching plastic microfluidic chip thermocompression bonding equipment is to provide effective processing equipment for the gradually expanding chip market.The main research contents of the paper are as follows:In order to improce the processing accuracy of the equipment,a combination of a servo motor and a screw lift was used in the equipment to constitute a pressurized system.The total pressure accuracy was ensured through the closed loop feedback of the load cell.The pressure accuracy on the three submodules was pre-commissioned to ensure a better pressure distribution uniformity.At the same time,both the upper pressure module and the lower pressure module are designed as self-balanced.A temperature control system using a TEC as a heating and cooling device was designed and the heating and cooling power of the TEC was calculated.The vacuum chamber of the device was designed to be a sealed system with a variety of sealing forms.The overall performance of the vacuum hot press machine was experimentally tested.The experimental scheme was designed and experiments were conducted on and the pressure temperature control performance vacuum performance experiment,and hot pressing and bonding comparison.The pressure in the vacuum chamber was tested and the comparison experiments showed that bonding in a vacuum environment could reduce the occurance of bubbles to a large extent.Embossing experiement was carried out on organic polymer PMMA.with silicon wafer as the substrate,an embossing mold was electroformed by UV-LIGA technology to perform an imprinting experiment.The microfluidic chip substrate with complete microstructure was fabricated by machining,and the pressure,temperature,vacuum accuracy of the equipment and related influencing factors were analyzed.The comparison experiment of hot pressing and bonding were performed to analyze the overall performance of the equipment.