Sanyu Rec Co., Ltd.

Japan Rec Co., Ltd.

Casio Computer Co., Ltd.

Atsushi Okuno

Yuki Ishikawa

Koichiro Nagai

Noritaka Oyama

Tsunekazu Hashimoto

Noriko Fujita

Masajiro Inoue

The invention provides a method for producing semiconductor packages comprising the steps of forming electronic circuits for a plurality of semiconductor chipson a waferforming bumpson the plurality of semiconductor chipsencapsulating the circuit-forming surfaceof the waferand the bumpswith a sealant by screen printing means to form a sealant layercuring the sealant layergrinding the surface of the sealant layeruntil the upper end surface of the bumpbecomes exposed, placing solder balls on said upper end surface of bumpsto weld the balls to the surface thereof, and dicing the waferand the sealant layeras united into individual semiconductor chipsScreen printing means is used to encapsulate the entire surface of the wafer with a resin, so that the equipment costs can be markedly reduced as compared with conventional methods using a mold.

Method for production of semiconductor package

An object of the present invention is to present a fabrication method for electronic components that allows further reduction in the size of electronic components by making the semiconductor substrate thinner, and at the same time allows operation as an electronic circuit with no problems, and further, has a durability sufficient to endure even use in a mobile telephone. In order to attain this object, the present invention has a first application process (process S ) in which encapsulating resin is applied to the surface of the substrate on which the posts are formed, a back surface grinding process (process S ) in which the back surface of said substrate is ground, a second application process (process S ) in which an encapsulating resin is applied to the back surface of said substrate after being ground, and a separation process (process S ) in which said substrate is cut along with said encapsulating resin and at the same time individual electronic components are separated.

Fabrication method of an electronic component

The invention provides a method for producing semiconductor packages comprising the steps of forming electronic circuits for a plurality of semiconductor chips 11 on a wafer 1, forming bumps 2 on the plurality of semiconductor chips 11, encapsulating the circuit-forming surface 111 of the wafer 1 and the bumps 2 with a sealant by screen printing means to form a sealant layer 4, curing the sealant layer 4, grinding the surface of the sealant layer 4 until the upper end surface of the bump 2 becomes exposed, placing solder balls on said upper end surface of bumps 2 to weld the balls to the surface thereof, and dicing the wafer 1 and the sealant layer 4 as united into individual semiconductor chips 11. Screen printing means is used to encapsulate the entire surface of the wafer with a resin, so that the equipment costs can be markedly reduced as compared with conventional methods using a mold.

A method of sealing electric parts mounted in a bare state on an electric wiring board uses a liquid sealing resin as a printing ink and a screen serving as screen printing means and having apertures in the same pattern as the electric parts mounted on the board. The lower end of a peripheral wall of the screen defining each of the apertures is substantially brought into line-to-line contact with the surface of the board for screen printing. The screen has a recess formed on the rear side of the line contact portion thereof and surrounding the contact portion. These features prevent the printing ink from adhering to the rear side of the screen and the collapse of the sealing resin layer that would occur if the ink adheres to the screen rear sides.

Growing community of inventors

Osaka-fu, Japan

Atsushi Okuno