SEMICONDUCTOR DEVICE PACKAGING

• US 3,706,840 A
• Filed: 05/10/1971
• Issued: 12/19/1972
• Est. Priority Date: 05/10/1971
• Status: Expired due to Term

• Current Assignee: Kenneth J. Moyle, Richard S. Mann
• Original Assignee: Kenneth J. Moyle, Richard S. Mann
• Inventors: Moyle, Kenneth J., Mann, Richard S.
• Primary Examiner(s): Clay, Darrell L.
• Application Number:
  US05/141,793
• Time in Patent Office: 589 Days
• Field of Search: 174/52PE,52R 264/272 317/234E,234G,11A,11CP 29/626,588 317/234F
• US Class Current: 174/524
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/3135 Double encapsulation or coating and encapsulation
• CPC Class Codes: H01L 23/49861 Lead-frames fixed on or encapsulated in insulating substrates H01L23/4985, H01L23/49805 take precedence
• CPC Class Codes: H01L 24/48 of an individual wire connector
• 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 2924/00012 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 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: Y10T 29/49121 Beam lead frame or beam lead device

Abstract

An improved semiconductor device package and process of manufacture incorporating an inner rigid glass structure including mounting pad and lead fingers and a surrounding plastic package through which leads extend.

Claims

1. A process for packaging a semiconductor device comprising fusing glass to the central portion of a lead frame having leads and a mounting pad to form a glass base beneath such portion and an upstanding glass wall upon the frame surrounding the mounting pad and adjacent lead fingers of the frame to form a central rigid package portion, securing a semiconductor device upon the mounting pad and connecting device contacts to lead fingers within the wall of the central package portion, applying a conformal coating over the device and connections within the glass wall, and molding a plastic encapsulant about the central portion of the package enclosing the same with the extremities of the lead frame extending therefrom.

2. The process of claim 1 including the step of depressing the lead frame mounting pad in the glass during fusing of the glass to dispose the pad below the lead fingers.

3. The process of claim 1 wherein the step of applying said conformal coating comprises substantially filling the well within said upstanding wall with a liquid thermosetting encapsulant material and heating the material to solidify the material.

4. The process of claim 1 wherein the steP of fusing the glass to the lead frame comprises disposing a glass plate beneath the center of the lead frame, disposing a glass ring atop the lead frame and applying heat and pressure to the glass to hermetically seal the glass to the frame and fuse the ring and plate together.

5. The process of claim 1 additionally including the step of cutting away the outer extremity of the lead frame to leave individual leads extending from the encapsulated semiconductor device as connectors thereof.

6. A method of packaging a semiconductor device wherein the device is mounted upon a central pad of a lead frame, comprising a. disposing a glass plate beneath the lead frame pad and extending outwardly beneath lead fingers of the frame, b. disposing an upstanding glass wall upon the lead frame about the frame pad and a short inner extension of lead fingers, c. fusing the frame and glass together to form a rigid central structure of the lead frame, d. mounting a semiconductor device on the top of the frame pad and electrically connecting device terminals to lead fingers within the glass wall, e. sealing the device and electrical connections within the glass wall with a conformal coating, and f. molding a plastic encapsulant about the central structure including device and connections enclosing the same but excluding the outer ends of leads of the frame.

7. An improved packaged semiconductor device comprising a central rigid structure of electrically insulating glass with a flat base and an upstanding wall thereabout, a device mounting pad disposed upon the upper surface of said base within said wall and having a semiconductor device mounted thereon, a plurality of metal leads extending through said wall and fused thereto with short lead fingers extending into close proximity to said pad on the glass base and substantial extensions exteriorly of said glass wall, said leads being electrically connected to said device, an encapsulant disposed within said glass wall in enveloping and sealing relation to the device on said pad and the connections between the device and lead fingers, and a plastic encapsulation enclosing said rigid central structure and extending laterally beyond same short of the ends of said metal leads and bonded to the structure and leads with lead ends extending therefrom as connectors for the packaged device.

8. The package of claim 7 wherein said plurality of metal leads are formed of a nickel-iron-cobalt alloy and said glass is fused thereto forming a hermetic seal to the leads.

9. The package of claim 7 wherein said device mounting pad is disposed slightly below said lead fingers interiorly of said glass wall.

10. A process for packaging a semiconductor device having contacts comprising heating a cup-shaped glass element only to softening temperature, forcing a metal lead frame having leads and a mounting pad downwardly into the softened glass to sink the frame at least to the upper surface of the cup bottom with the frame mounting pad and lead fingers disposed within the cup and the leads extending through the cup walls exteriorly thereof to form a central rigid package portion, securing a semiconductor device upon said mounting pad within the cup-shaped glass element, bonding wires to and between the lead fingers and the device contacts for interconnection thereof within said element, sealing said device and wires within said element, and molding a plastic encapsulant in enclosing relation about the rigid central portion of the package with the extremities of the lead frame extending therefrom as connectors for the packaged device.