3D packaging solutions for a silicon micropump

A novel microsystem incorporating a micromachined silicon membrane pump, packaged in a 3D MCM-V package is described. Finite element techniques are used to analyse the encapsulation stress in the assembled structure and the silicon membrane. The design of the silicon chip carrier substrates is improved by modifying the design of the cutting windows to reduce the risk of cracking. A combination of numerical and analytical techniques are used to deduce limits for the maximum permissible dimensions of the membrane to minimise the risk of buckling due to residual compressive stresses.