Title:
MOLDER
Document Type and Number:
Japanese Patent JPS61117842
Kind Code:
A
Abstract:
PURPOSE:To prevent the generation of voids in a package by a method wherein an air extraction is formed in the fitting surface of the upper die and the lower die at the part of pressure sensing of the lead frame dam. CONSTITUTION:Escapes 11a, 11b to increase the surface pressure are formed at the dam hold parts 6a, 7a and 6b, 7b of the upper die 1 and the lower die 2, respectively, slightly off the cavity 3. A plurality of auxiliary air extractors 12 are arranged at the dam hold parts 6a, 6b of the upper die 1 so as to correspond to the gaps between the adjacent leads in the lead frame, and are opened so as to connect the escapes 11a, 11b with the cavity 3. Therefore, the air in the cavity 3 is exhausted out of many auxiliary air extractions 12 opened at the dam hold parts 6a, 6b, 7a, and 7b in all directions to the surface pressure escapes 11a, 11b; accordingly, voids due to the insufficient exhaust of air do not generate.
Inventors:
ITO FUJIO
KOIZUMI KOJI
WAKASHIMA YOSHIAKI
NISHI KUNIHIKO
OZAWA MASAKAZU
KOIZUMI KOJI
WAKASHIMA YOSHIAKI
NISHI KUNIHIKO
OZAWA MASAKAZU
Application Number:
JP23839084A
Publication Date:
June 05, 1986
Filing Date:
November 14, 1984
Export Citation:
Assignee:
HITACHI MICROCUMPUTER ENG
HITACHI LTD
HITACHI LTD
International Classes:
H01L21/56; B29C45/02; B29C45/14; B29C45/34; B29K101/10; B29L31/34; (IPC1-7): B29C45/02; B29C45/14; B29C45/34; B29K101/10; B29L31/34
Attorney, Agent or Firm:
Akio Takahashi