Apparatus for packaging flip chip bare die on printed circuit boards

• US 5,898,224 A
• Filed: 10/22/1997
• Issued: 04/27/1999
• Est. Priority Date: 01/24/1997
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Akram, Salman
• Primary Examiner(s): Arroyo, Teresa M.
• Application Number:
  US08/956,143
• Time in Patent Office: 552 Days
• Field of Search: 257/778, 257/787, 257/659, 257/660
• US Class Current: 257/778
• CPC Class Codes: H01L 21/563 Encapsulation of active face of flip-chip device, e.g. underfilling or underencapsulation of flip-chip, encapsulation preform on chip or mounting substrate
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/73203 Bump and layer connectors
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 2224/73257 Bump and wire connectors
• CPC Class Codes: H01L 2224/75 Apparatus for connecting with bump connectors or layer connectors
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• CPC Class Codes: H01L 2224/83951 Forming additional members, e.g. for reinforcing, fillet sealant
• CPC Class Codes: H01L 23/16 Fillings or auxiliary members in containers or encapsulations, e.g. centering rings H01L23/42, H01L23/552 take precedence
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 23/585 comprising conductive layers or plates or strips or rods or rings H01L23/60, H01L23/62, H01L23/64, H01L23/66 take precedence
• CPC Class Codes: H01L 24/31 Structure, shape, material or disposition of the layer connectors after the connecting process
• CPC Class Codes: H01L 24/75 Apparatus for connecting with bump connectors or layer connectors
• CPC Class Codes: H01L 24/81 using a bump 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/16195 : Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 2924/3512 : Cracking

Abstract

An apparatus and a method for providing a fully protective package for a flip chip with a protective shield plate and an underfill encapsulant material. The apparatus comprises a semiconductor chip electrically connected by flip chip attachment to a substrate. A shield plate is placed in contact with a back surface of the semiconductor chip. An underfill encapsulant is disposed between the semiconductor chip and the shield plate, and the substrate. A glob top encapsulant may be applied about the periphery of the upper surface of the shield plate that extends to the substrate for additional protection and/or adherence.

Claims

1. A semiconductor assembly comprising:

a substrate having an upper surface and a lower surface, the upper surface of said substrate having at least one electrical connection thereon;

a semiconductor chip having a first surface and a second surface, the first surface of said semiconductor chip attached to the upper surface of said substrate and in electrical communication with the at least one electrical connection on the upper surface of said substrate;

a shield plate having a first surface, a second surface, and a periphery extending beyond a periphery of the semiconductor chip, the first surface of said shield plate contacting the second surface of said semiconductor chip; and

an underfill encapsulant disposed between the first surface of said semiconductor chip and the upper surface of said substrate and between the periphery of the first surface of said shield plate extending beyond the periphery of the semiconductor chip and a portion of the first surface of said shield plate and the upper surface of said substrate.

2. The semiconductor assembly of claim 1, wherein said shield plate includes polymer or plastic material.

3. The semiconductor assembly of claim 1, wherein said shield plate has a higher thermal conductivity than said semiconductor chip.

4. The semiconductor assembly of claim 3, wherein said shield plate includes metal, thermally conductive ceramic, or other thermally conductive material.

5. The semiconductor assembly of claim 1, further comprising a glob top material disposed on the second surface and the periphery of said shield plate, wherein said glob top material extends to and contacts said substrate.

6. The semiconductor assembly of claim 5, wherein said glob top material extends under a portion of the first surface of said shield plate.

7. The semiconductor assembly of claim 5, wherein said glob top material extends under a portion of the first surface of said shield plate to transfer heat from the semiconductor chip.

8. A semiconductor assembly comprising:

a substrate having an upper surface and a lower surface, the upper surface having at least one electrical connector thereon;

a semiconductor chip having a first surface and a second surface, the first surface attached to the upper surface of the substrate and in electrical communication with the at least one electrical connector on the upper surface of said substrate;

a shield plate having a first surface, a second surface, and a periphery, the first surface of said shield plate contacting the second surface of the semiconductor chip;

an underfill encapsulant disposed between the first surface of the semiconductor chip and the upper surface of said substrate and between the first surface of said shield plate and and the upper surface of said substrate; and

a glob top material disposed on the second surface and the periphery of said shield plate, said glob top material extending to and in contact with the upper surface of said substrate and in contact with said underfill encapsulant.

9. The semiconductor assembly of claim 8, wherein said glob top material extends under a portion of the first surface of said shield plate.

10. The semiconductor assembly of claim 9, wherein said glob top material extends under a portion of the first surface of said shield plate for the transfer heat therefrom.