Bumped integrated circuits for optical applications

• US 6,707,148 B1
• Filed: 05/21/2002
• Issued: 03/16/2004
• Est. Priority Date: 05/21/2002
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Mostafazedeh, Shahram, Smith, Joseph O.
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): CRUZ, LOURDES C
• Application Number:
  US10/153,269
• Time in Patent Office: 665 Days
• Field of Search: 257/749, 257/704, 257/431, 257/432, 257/433, 257/434, 257/440, 174/52.1, 361/783, 361/820
• US Class Current: 257/704
• CPC Class Codes: H01L 2224/04105 Bonding areas formed on an encapsulation of the semiconductor or solid-state body, e.g. bonding areas on chip-scale packages
• CPC Class Codes: H01L 2224/12105 Bump connectors formed on an encapsulation of the semiconductor or solid-state body, e.g. bumps on chip-scale packages
• CPC Class Codes: H01L 2224/214 Connecting portions
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/73267 Layer and HDI connectors
• CPC Class Codes: H01L 23/3114 the device being a chip scale package, e.g. CSP
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• 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 2924/16195 Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements

Abstract

An optical integrated circuit application where the integrated circuit is packaged in a clear molding material and is attached to a printed circuit board having an aperture is described. The integrated circuit senses and/or emits light through the clear molding material and through the aperture in the printed circuit board.

Claims

1. An optical and electrical apparatus comprising:

a packaged integrated circuit that includes,

an integrated circuit having a first surface and a second surface, the first surface having a first set of light emitting or sensing devices and a plurality of bond pads;

a conductive bump formed on each of the respective bond pads;

a clear molding material that encapsulates the integrated circuit and a portion of each conductive bump such that each conductive bump is partially exposed through the clear molding material, whereby light can pass through the clear molding material and reach the first set of light emitting or sensing devices; and

an electrical substrate having a plurality of electrical contact points and a first aperture wherein the packaged integrated circuit is positioned together with the electrical substrate wherein at least some of the conductive bumps are connected to respective electrical contact points and wherein the first aperture is located over the first set of light emitting or sensing devices.

2. An optical and electrical apparatus as recited in claim 1 wherein the integrated circuit further comprises a second set of light emitting or sensing devices and the electrical substrate further comprises a second aperture wherein the second aperture is located over the second set of light emitting or sensing devices.

3. An optical and electrical apparatus as recited in claim 1 further comprising an optical fiber that is attached to the electrical substrate in a position over the first aperture such that the first set of light emitting or sensing devices is in optical communication with the optical fiber through the aperture of the electrical substrate.

4. An optical and electrical apparatus as recited in claim 1 further comprising a metal pad that is attached to the second surface of the integrated circuit wherein the metal pad is partially encapsulated by the clear molding material.

5. An optical and electrical apparatus as recited in claim 1 wherein the metal pad has locking ledges extending from the peripheral edges of the metal pad, whereby the locking ledges serve to lock the metal pad within the clear molding material.

6. An optical and electrical apparatus as recited in claim 1 wherein the electrical substrate is a printed circuit board.

7. An optical and electrical apparatus as recited in claim 1 wherein solder material is used to secure the connection between the conductive bumps and the electrical contact points.

8. An optical and electrical apparatus comprising:

a packaged integrated circuit that includes,

an integrated circuit having a first surface and a second surface, the first surface having a first and second set of light emitting or sensing devices and a plurality of bond pads;

a conductive bump formed on each of the respective bond pads;

a clear molding material that encapsulates the integrated circuit and a portion of each conductive bump such that each conductive bump is partially exposed through the clear molding material, whereby light can pass through the clear molding material and reach the first set of light emitting or sensing devices; and

an electrical substrate having a plurality of electrical contact points and a first and second aperture wherein the packaged integrated circuit is positioned on the electrical substrate wherein at least some of the conductive bumps are connected to respective electrical contact points and wherein the first and second apertures are located respectively over the first and second set of light emitting or sensing devices.

9. An optical and electrical apparatus as recited in claim 8 further comprising an optical fiber that is attached to the electrical substrate in a position over the first aperture such that the first set of light emitting or sensing devices is in optical communication with the optical fiber through the aperture of the electrical substrate.

10. An optical and electrical apparatus as recited in claim 8 further comprising a metal pad that is attached to the second surface of the integrated circuit wherein the metal pad is partially encapsulated by the clear molding material.

11. An optical and electrical apparatus as recited in claim 8 wherein the metal pad has locking ledges extending from the peripheral edges of the metal pad, whereby the locking ledges serve to lock the metal pad within the clear molding material.

12. An optical and electrical apparatus as recited in claim 8 wherein the electrical substrate is a printed circuit board.

13. An optical and electrical apparatus as recited in claim 8 wherein solder material is used to secure the connection between the conductive bumps and the electrical contact points.