HIGH DENSITY SEMICONDUCTOR MEMORY MODULE

摘要

A method and a memory module are provided which allow the duplication of the density of a memory module with a minimum of increasing of the module size and with low manufacturing costs. The method uses well-known techniques which are used by the manufacturing of DIP modules containing only one chip inside the moulded plastic or ceramic housing. Contrary to with the common methods the inner bond leads are punched so that they have a greater width than the common inner bond leads. Subsequently or together with the punching step the inner bond leads are slotted in order to allow the bending of at least one of each of the smaller inner bond leads obtained before for providing a space between the two inner bond leads. Next, two semiconductor memory chips are glued together back-to-back and inserted in the gap between the upper inner bond leads and the lower inner bond leads so that the upper and lower bond leads embrace the two chips. The chips can be equal with the pad occupation, or mirrored. The method is applicable to dual inline package (DIP) as well as to ZIG-ZAG package. The semiconductor memory module comprises a housing (4) of plastic or ceramic in which two chips (8, 10) are stacked together back-to-back. The pads (20) of the chips are electrically connected by wire-bonding to beam leads (14) which comprise outer bond leads (6), generally arranged outside the housing to form the ocntact pins or contact leads of the module to a printed circuit board, and inner bond leads (16) in the housing. The inner bond leads are spread in the area of the inner lead bond ends into upper (16a) and lower (16b) bond leads forming a gap (22) for receiving and embracing the stacked chips.