Physical Approach For Area Array Packaging Terminal

With the continuous miniaturization of electronic components and integrated direction of development,new packaging technologies continue to emerge.Bar Grid Array CGA is one of the few package types currently available in mass production with more than 1000 I / O ports.It is a development and improvement of ball grid arrays for better heat dissipation and fatigue resistance.However,for CGA this high-density,narrow pitch,large size of the device,at present there is no evaluation of the quality of its packaging testing standards.In order to evaluate the reliability of CGA devices and establish practical and feasible detection methods,this project will study the test methods of CGA devices from three aspects of coplanarity,tensile strength and shear strength of CGA devices.The first is the study of coplanarity test methods.The coplanarity test method mainly includes the regression plane method and the reference plane method.In view of the actual welding process of the device,the paper researches the reference plane method,light and dark shading method,the center method,the area array method and the contact measurement method to determine the reference plane method In the "Z-axis height",through the study found that the four methods can complement each other,the paper first proposed center-area method and the regional array method to avoid the light and dark shading method due to pollutants caused the device error,but also to avoid contact Irregular damage to the lead end due to the measurement method.The second is to study the test method of tensile strength.Put forward tensile strength test procedure,equipment,test fixture selection and other requirements,innovatively developed a new tensile strength test fixture,to prove the feasibility of the new fixture.The influences of the pullout test speed,the test height and the position of the test column on the test results were studied.The recommended range of the test speed and the test height was given.At the same time,the sampling method was changed from the original random Sampling changed to directional sampling.This provides a theoretical and practical basis for the development of CGA tensile strength test methods and the practical application of the method.Finally,the test method of column shear strength is studied.The test procedure,equipment and test fixture selection requirements were put forward.The influences of test speed,test height and position of test column on the test results were studied.Shear strength test rate and the recommended range of test height,and changed the sampling method from the original random sampling to directional sampling.This provides a certain theoretical and practical basis for the CGA column shear stress test method and the actual test method used.