Multimold semiconductor device and the manufacturing method therefor

• US 5,057,457 A
• Filed: 09/11/1990
• Issued: 10/15/1991
• Est. Priority Date: 09/13/1989
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Miyahara, Syouichi, Higashi, Michiya, Kamasaki, Keiji
• Primary Examiner(s): Hille, Rolf
• Assistant Examiner(s): CLARK, SHEILA V
• Application Number:
  US07/580,542
• Time in Patent Office: 399 Days
• Field of Search: 357/72, 357/74, 437/217, 437/218, 437/219, 437/927, 437/206, 437/207, 437/211, 437/220, 174/52.4, 264/272.17
• US Class Current: 264/272.14
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 23/293 Organic, e.g. plastic
• CPC Class Codes: H01L 23/3135 Double encapsulation or coating and encapsulation
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 25/0652 the devices being arranged next and on each other, i.e. mixed assemblies
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation

Abstract

In multimold semiconductor devices, semiconductor chips are mounted on a lead frame and bonded with wire, sealed by an inner resin, and further enclosed by an outer resin. In particular, wax to be added to the inner resin is at least one compound selected from the group consisting of ester group, fatty acid based, fatty acid metallic salt based, fatty alcohol, polyhydric alcohol, and fatty acid amide compounds. In the semiconductor devices sealed by the inner resin including wax thus defined, since the adhesion strength between the inner and outer resins can be increased, peeling resistance between the two and the moisture resistance can be improved markedly and cracks after dip soldering can be perfectly eliminated, without effecting any conventional inner resin treatment such as honing, burning, after-curing, etc.

Claims

1. A method of manufacturing semiconductor devices which comprises the following steps of:

(a) arranging semiconductor chips mounted on a lead frame and bonded with wires in cavities formed in an inner resin mold;

(b) injecting melted inner resin into an inner resin mold, wax to be added to the inner resin being at least one compound selected from the group consisting of ester group compound, fatty acid based compound, fatty acid metallic salt based compound, fatty alcohol compound, polyhydric alcohol compound, and fatty acid amide compound;

(c) removing the hardened inner resin sealed semiconductor devices from the inner resin mold;

(d) arranging the removed inner resin sealed semiconductor devices in cavities formed in an outer resin mold;

(e) injecting an outer resin into the outer resin mold; and

(f) removing the hardened outer resin enclosed semiconductor devices from the outer resin mold.