Conductive encapsulating shield for an integrated circuit

• US 5,679,975 A
• Filed: 12/18/1995
• Issued: 10/21/1997
• Est. Priority Date: 12/18/1995
• Status: Expired due to Fees

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Inventors: Templeton, Thomas Henry Jr., Wyland, Christopher Paul
• Primary Examiner(s): Saadat, Mahshid D.
• Assistant Examiner(s): CLARK, SHEILA V
• Application Number:
  US08/574,049
• Time in Patent Office: 673 Days
• Field of Search: 257/659, 257/787
• US Class Current: 257/659
• CPC Class Codes: H01L 2224/05553 being rectangular
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45015 being circular
• 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 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/85399 Material
• 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 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• 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 2924/10162 with a square active surface
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/207 Diameter ranges
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding

Abstract

A conductive shield on the surface of an integrated circuit package improves the circuit and package performance. The conductive shield in the vicinity of the leads reduces lead inductance, thus increasing the frequency range of the package and reducing switching induced noise in digital circuits. The shield also blocks radio energy from entering or leaving the package through shielded area.

Claims

1. A packaged integrated circuit comprising:

an integrated circuit die comprising bond pads;

a plurality of leads extending away from the integrated circuit die;

means for connecting the bond pads to the leads;

an insulative member encapsulating the integrated circuit die, the means for connecting, and an inner portion of the leads, the insulative member having an outer surface including a first portion located above the leads and a second portion located above the integrated circuit die; and

a conductive shield attached to the outer surface of the insulative member wherein the conductive shield covers only the first portion of the outer surface of the insulative member.

2. The packaged integrated circuit of claim 1, wherein the conductive shield comprises a metal layer.

3. The packaged integrated circuit of claim 1, wherein the conductive shield comprises a metal alloy layer.

4. The packaged integrated circuit of claim 1, wherein the conductive shield comprises conductive paint.

5. The packaged integrated circuit of claim 1, wherein the conductive shield comprises a molding compound containing a conductive filler.

6. The packaged integrated circuit of claim 1, further comprising means for connecting the conductive shield to a fixed voltage source.

7. The packaged integrated circuit of claim 6, wherein the means for connecting the conductive shield to a fixed voltage source comprises a package lead.

9. The packaged integrated circuit of claim 1, further comprising:

a lower conductive shield attached to the outer surface of the insulative member wherein the lower conductive shield covers a portion of the outer surface of the insulative member below the leads.

8. A method for manufacturing an integrated circuit comprising the steps of:

providing an integrated circuit die comprising bond pads;

providing a plurality of leads extending away from the integrated circuit die;

connecting the bond pads to the leads;

forming for the integrated circuit an insulative package body, the insulative package body having an outer surface, wherein a first portion of the outer surface is located above the leads and a second portion of the outer surface is located above the integrated circuit die; and

forming a conductive shield on a first portion of the outer surface of the insulative package body.

10. An integrated circuit package having an integrated circuit die and a plurality of leads extending away from the integrated circuit die, the integrated circuit package further comprising:

an electrically insulative package body surrounding the integrated circuit die, the electrically insulative package body having an outer surface including a first portion located above the leads and a second portion located above the integrated circuit die;

a first conductive shield on the first portion of the outer surface, the first conductive shield having a first conductivity; and

a second conductive shield on the second portion of the outer surface, the second conductive shield having a second conductivity different from the first conductivity.

11. The integrated circuit package of claim 10, wherein the first conductive shield and the second conductive shield form a single shield.

12. An integrated circuit package having an integrated circuit die and a plurality of leads extending away from the integrated circuit die, the integrated circuit package further comprising:

an electrically insulative package body surrounding the integrated circuit die, the electrically insulative package body having an outer surface including a first portion located above the leads and a second portion located above the integrated circuit die;

a first conductive shield on the first portion of the outer surface; and

a second conductive shield on the second portion of the outer surface.

13. The integrated circuit package of claim 12, wherein the first conductive shield and the second conductive shield have different conductivities.