Embedding chip into substrates with cavities for hetergeneous integration

Abstract

Technologies for the embedding of active and passive components into the multilayer substrate can effectively reduce the circuit length, improve the electrical performance and thermal properties through the designing of thermal path. It allows a large extent miniaturization of products' size and makes high density packaging enabled. In this paper, we embedded the organic interposer with flip-chip into the T-shaped cavity on the core substrate to form an embedded chip package structure. First of all, the thinned chip was flip-mounted on an organic interposer with solder bump, the interposer was fabricated with the circuit pattern as the lead-out module, and meanwhile a T-shaped cavity was machined on an organic core substrate by 355nm laser, which matches the shape of the interposer with chip. Then the interposer was placed in the T-cavity and the core substrate was covered with some prepreg layers. Next embedding chip into substrate was processed by a vacuum lamination machine. At last, laser drilling was used for blind via formation connecting to the pads on the interposer, and via metallization was implemented by vertical PTH and plating process. After the whole processes, thermal cycle test was performed. Results show that the embedded process was demonstrated successfully, and there were no cracks on the die and no voids in the embedded structure. Finally, the steady-state thermal analysis of the embedded substrate was taken to improve the thermal performance and optimum of the embedded substrate.