Method for producing channels and cavities in semiconductor housings, and an electronic component having such channels and cavities

• US 20040067603A1
• Filed: 10/02/2003
• Published: 04/08/2004
• Est. Priority Date: 10/02/2002
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Hagen, Robert-Christian
• Granted Patent: US 6,949,405 B2
• Time in Patent Office: Days
• US Class Current: 438/106
• CPC Class Codes: G01L 19/141 Monolithic housings, e.g. molded or one-piece housings
• CPC Class Codes: G01P 1/02 Housings
• CPC Class Codes: H01L 21/565 Moulds
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/451 with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
• 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 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/3107 the device being completely enclosed
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• 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 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01068 Erbium [Er]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/12042 LASER
• CPC Class Codes: H01L 2924/12043 : Photo diode
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape

Abstract

An electronic component is produced by incorporating a sacrificial part in a plastic housing shape. After molding, the sacrificial part is etched out or otherwise removed from the completed plastic housing. As a result, channels and/or cavities can be formed in the plastic housing in order to allow access to sensor areas on the semiconductor chip.

Claims

1. A method for producing an electronic component, which comprises the following method steps:

providing a semiconductor chip on a circuit mount, the semiconductor chip having an active upper face with at least one sensor area;

applying a sacrificial part to the sensor area of the semiconductor chip;

introducing the semiconductor chip with the circuit mount and the sacrificial part into an injection-molding mold;

filling the injection-molding mold with a plastic housing compound, for embedding the components in the injection-molding mold, and for forming packaged components;

removing the packaged components from the injection-molding mold; and

etching out or removing the sacrificial part from the plastic housing compound, for forming at least one void in the plastic housing compound.

2. The method according to claim 1, wherein the void is selected from the group of channels and cavities.

3. The method according to claim 1, wherein the sacrificial part has an area element and which comprises introducing the semiconductor chip with the circuit mount and the sacrificial part into the injection-molding mold, with the area element of the sacrificial part touching an inner wall of the injection-molding mold.

4. The method according to claim 1, which comprises providing a bonding wire or a bonding strip as the sacrificial part and mounting the sacrificial part by bonding on the sensor area of the semiconductor chip.

5. The method according to claim 1, which comprises adhesively bonding the sacrificial part onto the sensor area of the semiconductor chip.

6. The method according to claim 1, which comprises covering the inner wall of the injection-molding mold with a sheet before introducing the components to be packaged into the injection-molding mold, such that the projecting area element of the sacrificial part projects into the sheet when the injection-molding mold is closed.

7. The method according to claim 1, wherein, after the step of removing the packaged components from the injection-molding mold, an area element of the sacrificial part is not covered by the plastic housing compound.

8. The method according to claim 1, which comprises removing the sacrificial part selectively by way of an etching solution or a dry etching process.

9. The method according to claim 1, which comprises removing the sacrificial part selectively by way of a dry etching process in a plasma composed of reactive gases.

10. An electronic component, comprising:

at least one semiconductor chip having an active upper face with at least one sensor area; and

a plastic housing enclosing said at least one semiconductor chip, said housing having a void formed therein extending between an opening on a surface of said plastic housing and said at least one sensor area on said semiconductor chip, said void being formed with an undercut in a direction towards said sensor area of said semiconductor chip.

11. The electronic component according to claim 10, wherein said void is one or more three-dimensionally curved channels.

12. The electronic component according to claim 10, wherein said void is a channel or a cavity.

13. The electronic component according to claim 10, wherein said void has a larger cross section toward said sensor area than said opening.

14. The electronic component according to claim 10, wherein said sensor area is a part of a pressure sensor, a gas sensor, a liquid sensor, an acceleration sensor, or a photosensor.

15. The electronic component according to claim 10, wherein said void has an external contour of a preshaped sacrificial part encapsulated in a plastic housing compound forming said housing.

16. The electronic component according to claim 10, wherein at least one part of said void has an external contour of a bonding wire, of a bonding head, or of a bonding clip.

17. The electronic component according to claim 10, wherein said housing is formed of a plastic housing compound having ceramic particles up to a filling level of between 60 and 95% by weight, and a polymer plastic or an epoxy resin.

18. An electronic component, comprising:

at least one semiconductor chip having an active upper face with at least one sensor area; and

a plastic housing enclosing said at least one semiconductor chip, said housing having at least one three-dimensionally curved channel formed therein extending between an opening on a surface of said plastic housing and said at least one sensor area on said semiconductor chip.

19. The electronic component according to claim 18, wherein said channel is formed with an undercut in a direction towards said sensor area of said semiconductor chip.

20. The electronic component according to claim 18, wherein said channel has a larger cross section toward said sensor area than said opening.

21. The electronic component according to claim 18, wherein said sensor area is a part of a pressure sensor, a gas sensor, a liquid sensor, an acceleration sensor, or a photosensor.

22. The electronic component according to claim 18, wherein said channel has an external contour of a preshaped sacrificial part encapsulated in a plastic housing compound forming said housing.

23. The electronic component according to claim 18, wherein at least one part of said channel has an external contour of a bonding wire.

24. The electronic component according to claim 18, wherein said housing is formed of a plastic housing compound having ceramic particles up to a filling level of between 60 and 95% by weight, and a polymer plastic or an epoxy resin.