Process for hermetically encapsulating semiconductor devices

• US 4,355,463 A
• Filed: 03/24/1980
• Issued: 10/26/1982
• Est. Priority Date: 03/24/1980
• Status: Expired due to Term

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Burns, Carmen D.
• Primary Examiner(s): Husar, Francis S.
• Assistant Examiner(s): Arbes, Carl J.
• Application Number:
  US06/133,053
• Time in Patent Office: 946 Days
• Field of Search: 357/72, 357/81, 357/80, 357/70, 357/71, 29/412, 29/413, 29/414, 29/846, 29/827, 29/847, 29/576 S, 174/52 FP, 174/52 PE
• US Class Current: 29/827
• CPC Class Codes: H01L 21/50 Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
• CPC Class Codes: H01L 23/49541 Geometry of the lead-frame
• CPC Class Codes: H01L 24/50 Tape automated bonding [TAB] connectors, i.e. film carriers; Manufacturing methods related thereto thin flexible metallic tape with or without a film carrier H01L23/49572, flexible insulating substrates H01L23/4985, H01L23/5387
• CPC Class Codes: H01L 24/79 Apparatus for Tape Automated Bonding [TAB]
• CPC Class Codes: H01L 24/86 using tape automated bonding [TAB]
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01025 Manganese [Mn]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01075 Rhenium [Re]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/15153 the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/15165 Monolayer substrate
• CPC Class Codes: H01L 2924/15787 Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: Y10T 29/49121 Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/49139 by inserting component lead or terminal into base aperture
• CPC Class Codes: Y10T 29/4979 Breaking through weakened portion

Abstract

A tape assembly process attaches semiconductor chips to a tape via thermocompression gang bonding and the tape is wound onto a reel. The tape is fabricated during its manufacture to have a plurality of spaced finger array patterns. The inner finger ends are located so as to mate with the bonding pads of a semiconductor device and are bonded thereto. A ring-shaped strip is included in each finger pattern that joins all of the fingers in each pattern into a unitary structure in which the fingers are accurately spaced. Where the ring joins onto the fingers, weakened regions are introduced and the side of the tape that contains the semiconductor device includes a recess that is in registry with the ring. A ceramic substrate that will ultimately mount the semiconductor device is provided with an array of conductor patterns that match the tape finger patterns. A layer of sealing glass is screened over the ceramic, so as to align with the ring. Then the tape fingers are thermocompression bonded to the metal pattern, so that a bond is created for each finger on both sides of the glass. The ring is then mechanically stripped away with the weakened regions determining where the metal will rupture. This leaves a finger element on each side of the glass ring with the underlying conductor providing electrical continuity. The glass ring can then be joined to a ceramic cover that has a matching glass ring. The assembly is heat sealed to provide a hermetic housing.

Claims

1. A tape assembly process for hermetically encapsulating semiconductive devices secured to a tape having a plurality of fingers defining a plurality of metal finger patterns, one pattern each for each semiconductive device, said finger patterns including an inner end arrayed to conform with the contact pads of the semiconductive device which is secured thereto, said process comprising the steps:

applying a series of conductive patterns around the periphery of a first ceramic part that is to become a portion of a housing for said semiconductive device, said conductive patterns being arrayed so that individual conductors register with said fingers in said finger patterns and radiate outward toward an outer edge of said first ceramic part;

applying a first ring of sealing glass over said conductive patterns so as to lie wholly within said conductive patterns which thereby extend on both sides of said first ring;

forming a metal ring on said metal finger pattern, thereby to mechanically join the fingers thereof together in each successive pattern on said tape, said metal ring having regions of mechanical weakness where it joins each finger and being shaped so as to conform with said first glass ring;

aligning said first ceramic part with respect to said tape so that said first glass ring is located in registry with said metal ring;

bonding said fingers in said patterns to said conductive patterns to secure adherence thereto, on both sides of said glass ring, whereby said metal ring lies over said glass ring;

removing said metal ring by stripping so as to break said regions of mechanical weakness, thereby exposing said first glass ring;

forming a second ceramic part that mates with said first ceramic part;

applying a second ring of sealing glass to the periphery of said second ceramic part to conform to said glass ring on said first ceramic part;

bringing said first and second ceramic parts together so that said first and second glass rings abut; and

sealing said first and second ceramic parts together by means of said first and second glass rings.

2. The process of claim 1, wherein said first ceramic part includes a cup for accommodating said semiconductor device.

3. The process of claim 2 further including the step of securing said semiconductor device to the bottom of said cup.

4. The process of claim 1, wherein said first ceramic part is flat and said second ceramic part includes a cup to accommodate said semiconductor device.

5. The process of claim 4 further including the step of securing said semiconductor device to said first ceramic part.

6. The process of claim 1, wherein both said first and second ceramic parts are cup shaped to accommodate said semiconductor device.

7. The process of claim 1, further including the step of shaping said metal fingers so that they clear said first glass ring.

8. The process of claim 7, wherein said shaping is achieved by etching said fingers during the making of said tape.

9. The process of claim 7, wherein said shaping is achieved by mechanical deformation of said fingers.

10. The product manufactured by the process of claim 1.