Renesas Technology Corp.

Hitachi Ulsi Systems Co., Ltd.

Yoichi Kawata

Tamaki Wada

Kenichi Imura

Atsushi Fujishima

Takahiro Osawa

A method for manufacturing a multi media card comprises the steps of: providing a substrate, mounting a first flash memory chip and a controller chip for controlling the flash memory chip over a front surface of the substrate, molding the first flash memory chip and the controller chip by a resin, providing a case having a main surface and a back surface, wherein the back surface of the case has a first recess and a second recess, and, covering the resin and the front surface of the substrate by the case. The depth of the first recess is deeper than the depth of the second recess. The resin is fitted in the first recess. An edge portion of the substrate is fitted in the second recess. The substrate warps so that a central portion of the substrate projects in a direction away from the case.

Method of manufacturing a memory card

A memory card wherein a substrate is affixed to a cap is formed without the projection of substrate edges from a back surface of the cap. The memory card includes a substrate having a sealing member bonded to a recess in the cap. By utilizing a difference in thermal expansion coefficient between the sealing member and the substrate, the substrate is warped so that its central portion projects away from the cap. The shallow recess is deeper than the sum of the thickness of the substrate and the thickness of an adhesive for bonding the substrate to the bottom of the shallow recess, whereby peripheral edges of the substrate retract into the shallow recess without projecting from the back surface of the cap. The cap is shaped as a card several millimeters thick. A memory chip and control chip are incorporated in the sealing member.

Growing community of inventors

Higashiyamato, Japan

Yoichi Kawata