Fan-out semiconductor chip assembly

• US 6,265,765 B1
• Filed: 09/23/1997
• Issued: 07/24/2001
• Est. Priority Date: 07/07/1994
• Status: Expired due to Term

• Current Assignee: Tessera, Inc. (Adeia Inc.)
• Original Assignee: Tessera, Inc. (Adeia Inc.)
• Inventors: Smith, John W., DiStefano, Thomas H., Faraci, Tony
• Primary Examiner(s): POTTER, ROY KARL
• Application Number:
  US08/935,962
• Time in Patent Office: 1,400 Days
• Field of Search: 257/678, 257/723, 257/701, 257/702, 257/778, 257/738
• US Class Current: 257/678
• CPC Class Codes: H01L 21/4839 Assembly of a flat lead with an insulating support, e.g. for TAB
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 2224/81904 by means of an encapsulation layer or foil
• CPC Class Codes: H01L 23/22 liquid at the normal operating temperature of the device
• CPC Class Codes: H01L 23/49811 Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads H01L23/49827 takes precedence
• CPC Class Codes: H01L 23/49816 Spherical bumps on the substrate for external connection, e.g. ball grid arrays [BGA]
• CPC Class Codes: H01L 23/49827 Via connections through the substrates, e.g. pins going through the substrate, coaxial cables H01L23/49822, H01L23/49833, H01L23/4985, H01L23/49861 take precedence
• CPC Class Codes: H01L 23/4985 Flexible insulating substrates H01L23/49572 and H01L23/49855 take precedence
• CPC Class Codes: H01L 23/642 Capacitive arrangements H01L23/49589, H01L23/645, H01L23/647, H01L23/66 take precedence; capacitive effects between wiring layers on the semiconductor body H01L23/5222
• CPC Class Codes: H01L 24/72 Detachable connecting means consisting of mechanical auxiliary parts connecting the device, e.g. pressure contacts using springs or clips
• 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 2924/00014 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 2924/01004 Beryllium [Be]
• 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 2924/01027 Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15174 : in different layers of the multilayer substrate
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/19105 : in a side-by-side arrangement on a common die mounting substrate
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 2924/351 : Thermal stress
• CPC Class Codes: H05K 1/118 : specially for flexible printed circuits, e.g. using folded portions
• CPC Class Codes: H05K 2201/0133 : Elastomeric or compliant polymer
• CPC Class Codes: H05K 2201/0394 : Conductor crossing over a hole in the substrate or a gap between two separate substrate parts
• CPC Class Codes: H05K 2201/0397 : Tab
• CPC Class Codes: H05K 2201/09081 : Tongue or tail integrated in planar structure, e.g. obtained by cutting from the planar structure
• CPC Class Codes: H05K 2201/091 : Locally and permanently deformed areas including dielectric material
• CPC Class Codes: H05K 2203/063 : of preperforated insulating layer
• CPC Class Codes: H05K 3/361 : Assembling flexible printed circuits with other printed circuits
• CPC Class Codes: H05K 3/4084 : by deforming at least one of the conductive layers

Abstract

A packaged semiconductor chip including the chip, and a package element such as a heat sink is made by connecting flexible leads between contacts on the chip and terminals on a dielectric element such as a sheet or plate and moving the sheet or plate away from the chip, and injecting a liquid material to form a compliant layer filling the space between the package element and the dielectric element, and surrounding the leads. The dielectric element and package element extend outwardly beyond the edges of the chip, and physically protect the chip. The assembly may be handled and mounted by conventional surface mounting techniques. The assembly may include additional circuit elements such as capacitors used in conjunction with the chip.

Claims

1. A semiconductor chip assembly comprising:

(a) a subassembly including a semiconductor chip having a front surface with contacts thereon and a package element having a central region attached to the chip and a peripheral region extending outwardly away from the chip in horizontal directions generally parallel to the front face of the chip;

(b) a substantially imperforate dielectric clement overlying the subassembly, said dielectric element including a central region overlying the central region of the package element adjacent the chip, and a peripheral region extending outwardly from the central region of said dielectric element and overlying the peripheral region of the package element, said dielectric element having a top surface facing away from the subassembly and a bottom surface facing toward the subassembly and electrically conductive terminals on the top surface, at least some of the terminals being disposed in said peripheral region of said dielectric element;

(c) a compliant layer disposed between the subassembly and dielectric element and supporting the dielectric element above the subassembly; and

(d) vertically-extensive flexible first leads embedded in said compliant layer and extending upwardly from the contacts on the chip to the central region of the dielectric element, the flexible leads being electrically connected to the terminals.

2. An assembly as claimed in claim 1 wherein said dielectric element is a flexible dielectric sheet.

3. An assembly as claimed in claim 2 wherein said peripheral portion of said package element defines a substantially planar front surface facing toward the dielectric element, and wherein said compliant layer is of substantially uniform thickness beneath the peripheral region of the dielectric element.

4. An assembly as claimed in claim 3 wherein the central region of the dielectric element overlies the front face of the chip, wherein said front surface of said chip is substantially coplanar with said front surface of the package element, and the compliant layer is of substantially uniform thickness beneath the central and peripheral regions of the dielectric element.

5. An assembly as claimed in claim 4 wherein some of said terminals are disposed in the central region of the dielectric element and overly the chip.

6. An assembly as claimed in claim 4 wherein said first leads extend between the contacts on the chip and the bottom surface of the dielectric element in the central region of the dielectric element.

7. An assembly as claimed in claim 6 wherein the dielectric element has conductive vias extending from said bottom surface toward said top surface and from said top surface towards said bottom surface, said first leads being connected to said terminals by way of said vias.

8. An assembly as claimed in claim 7 wherein said dielectric element has horizontal conductors extending between the central and peripheral regions of the dielectric element, at least some of said terminals being connected to said first conductors by way of said horizontal conductors and said vias.

9. An assembly as claimed in claim 1 wherein said package element includes a metallic heat sink.

10. An assembly as claimed in claim 9 further comprising one or ore electrical circuit elements disposed between said heat sink and the peripheral region of the dielectric element, said one or more electrical circuit elements being connected to said chip.

11. An assembly as claimed in claim 10 wherein said dielectric element has horizontal conductors extending between the central and peripheral regions of the dielectric element, at least some of said terminals being connected to said first leads by way of said horizontal conductors, said circuit elements being connected to said chip by way of said horizontal conductors and said first leads.

12. An assembly as claimed in claim 11 further comprising second flexible leads embedded in said compliant layer and extending from said one or more circuit elements to the peripheral region of the dielectric element and electrically connected to said horizontal leads, said one or more circuit elements being connected to the chip by way of said second leads, horizontal conductors and first leads.

13. An assembly as claimed in claim 1 wherein said dielectric element is substantially rigid.

14. An assembly as claimed in claim 13 wherein said dielectric element includes one or more ceramic materials.

15. An assembly as claimed in claim 13 wherein said dielectric element includes a fiber-reinforced circuit board.