Synthesis Of Azole Silane And Its Application On PCB

Copper-based materials are widely used in the field of information transmission and aerospace due to their good dielectric constants.In recent years,the surge in demand for 5G substrates has rapidly promoted the research and development of copper-based materials with high-frequency microwave copper foil as the core.The black oxidation and brown oxidation are traditional inner layer treatment techniques,and they are used to enhance the bonding force between the copper surface and resin by etching the copper surface to create a rough shape.However,the electromagnetic interference and skin effect existing on the rough surface can easily cause a large amount of signal loss in the process of high-frequency signal transmission,which cannot meet the needs of high-frequency signal transmission.In contrast,chemical interface enhancement uses multifunctional organic molecules for copper surface anchoring,which has the advantages of smooth surface,high modifiability,and mild operating conditions.At present,the organic molecule modification of copper surface under non-etching conditions is still in the exploration stage,and the study of the binding mechanism between organic molecules and copper surface to realize the interfacial enhancement of copper-based materials has a broad application prospect in the development of copper composites.Based on the above research background,in this dissertaion,2-aminothiazole,imidazole and（3-Isocyanatopropyl）-triethoxysilane were used as raw materials to synthesize azole silane coupling agents TUPTES and IAPTES.Their structure were characterized by different teciniques,and the test data showed that imidazole and thiazole rings were introduced into the silane coupling agents,respectively.Focusing on the chemical modification technology of the copper-high frequency substrate interface,the hydrolysis and curing process of the azole silane film preparation process were studied,and the following results were obtained..（1）The optimal hydrolysis conditions for silane TUPTES were: DMA: UPW=85 g: 10 g,TUPTE concentration of 3%,pH=4,curing method of dip coating for 30 s,curing temperature of 80 °C,curing time of 70 min.The detailed analysis of the structure and chemical composition of the silane films using ATR-IR,SEM-EDS,and XPS confirmed that a uniform and dense TUPTES film was formed on the copper surface,and the curing of hydrolyzed TUPTES on the copper surface resulted in the polymerization of two functional groups,Si-OH formed Si-O-Cu with the hydroxyl group on the copper surface,and at the same time,self-condensation forms a Si-O-Si network structure;The heteroatom N/S of the thiazole ring forms a coordination bond of N-Cu/S-Cu with copper;The contact angle of TUPTES increased to 93°,with certain hydrophobicity and corrosion resistance,and the roughness decreased to Ra=34.9 nm,Rq=27.6 nm.（2）The best hydrolysis conditions of azolesilane IAPTES are: DMA: UPW=90 g: 5 g,IAPTES concentration is 9%,pH=4,curing method is dip coating 90 s,curing temperature80 °C,curing time 30 min.ATR-IR,SEM-EDS and XPS results all showed that IAPTES forms a uniform and dense layer of TUPTES on the copper surface.The film formation mechanism was similar to that of the TUPTES film,with Si-OH generated by hydrolysis and copper surface hydroxyl groups to form Si-O-Cu,and N in the imidazole ring and copper to form N-Cu coordination bonds,with a contact angle of 103.5° and a roughness of Ra=13.5nm and Rq=16.5 nm.（3）The azolesilane hydrolysis solution was applied to the PCB interlayer peel strength test,and two types of copper foil treatment solutions were prepared: ‘GliCAP’ process treatment solution and browning-azolesilane treatment solution.The roughness Ra of the treated copper foil was 34.9 nm and 13.5nm for the ‘GliCAP’ treatment,146 nm for the browning-azolesilane treatment,and 204 nm for the conventional browning treatment,as characterized by AFM.The micro-etching depth obtained by the ‘GliCAP’ process was0.174 μm,s 0.464 μm by the browning-azole silane treatment,and 1.16 μm by the traditional browning treatment.The peel strength（4.95 N/cm）measured by the ‘GliCAP’ process was less than that obtained by the browning-Copper foil treated with oxazole silane（6.82N/cm）.The maximum peel strength obtained by the traditional browning treatment was 9.57 N/cm.