Method to encapsulate bumped integrated circuit to create chip scale package

• US 6,468,832 B1
• Filed: 07/19/2000
• Issued: 10/22/2002
• Est. Priority Date: 07/19/2000
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Mostafazadeh, Shahram
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): TRAN, MAI HUONG C
• Application Number:
  US09/620,206
• Time in Patent Office: 825 Days
• Field of Search: 257/676, 257/737, 257/790, 257/788, 257/738, 438/127, 438/108
• US Class Current: 438/112
• CPC Class Codes: H01L 21/565 Moulds
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 23/3114 the device being a chip scale package, e.g. CSP
• CPC Class Codes: H01L 23/49503 characterised by the die pad
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• 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 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/15787 Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H01L 2924/351 Thermal stress

Abstract

An encapsulated bumped die is provided. Singulated bumped dice are attached to a die attach panel. The die attach panel and dice are placed in a mold, where the bumps are partially flattened. A mold compound is then used to encapsulate the dice and panel. The mold compound is cured. The encapsulated dice are then singulated. The encapsulated dice may then be directly mounted on a substrate such as a PC board. The encapsulation provides added protection to the dice.

Claims

1. A method for providing encapsulated bumped dice, comprising:

providing a plurality of singulated bumped dice wherein each bumped die has an active top side with a plurality of conductive bumps and a bottom side opposite from the top side;

attaching the bottom sides of some of the plurality of singulated bumped dice to a die attach panel;

encapsulating the plurality of dice attached to the die attach panel in a mold compound; and

singulating the encapsulated dice.

2. The method, as recited in claim 1, wherein the encapsulating the plurality of dice, comprises:

placing the singulated bumped dice attached to the die attach panel in a mold; and

injecting a molding compound into the mold.

3. The method, as recited in claim 2, wherein the placing the singulated bumped dice attached to the die attach panel into the mold, at least partially flattens the conductive bumps.

4. The method, as recited in claim 3, wherein the placing the singulated bumped dice attached to the die attach panel into a mold, comprises:

placing the singulated bumped dice attached to the die attach panel on a first platen, wherein the singulated bumped dice attached to the die attach panel has a total height and wherein the first platen has an inner surface upon which the die attach panel rests; and

placing an inner surface of a second platen against the plurality of conductive bumps of the bumped dice, wherein the distance between the inner surface of the first platen and the inner surface of the second platen is less than the total height of the singulated bumped dice attached to the die attach panel, and wherein the first platen and second platen form a cavity surrounding the bumped dice attached to the die attach panel, wherein the inner surface of the first platen and the inner surface of the second platen form part of the cavity.

5. The method, as recited in claim 4, further comprising the step of curing the mold compound.

6. The method, as recited in claim 5, further comprising forming the die attach panel, comprising:

forming a plurality of die attach pads; and

forming a plurality of ties connected between the die attach pads, wherein a plurality of apertures are formed between the ties, and where during the encapsulating the plurality of dice mold compound passes through the plurality of apertures.

7. The method, as recited in claim 6, further comprising the step of testing the plurality of bumped dice as a panel before singulating the encapsulated dice.

8. The method, as recited in claim 7, wherein the attaching the bottom sides of some of the plurality of singulated bumped dice to a die attach panel, comprises placing an adhesive between the bottom sides of some of the plurality of singulated bumped dice and the die attach pads.

9. The method, as recited in claim 8, wherein the providing a plurality of singulated bumped dice, comprises:

forming dice in a wafer;

attaching conductive bumps to the dice; and

singulating the dice.

10. The method, as recited in claim 9, wherein the forming the die attach panel, forms the die attach pads and ties from a metal sheet.

11. The method, as recited in claim 10, wherein the step of attaching conductive bumps attaches solder bumps.

12. The method, as recited in claim 11, wherein the step of encapsulating forms a surface of the molding compound which forms a single flat surface with surfaces of the partially flattened bumps.

13. The method, as recited in claim 1, further comprising forming the die attach panel from a metal sheet, comprising:

forming a plurality of die attach pads; and

forming a plurality of ties connected between the die attach pads.

14. The method, as recited in claim 1, further comprising the step of testing the plurality of bumped dice as a panel before singulating the encapsulated dice.

15. The method, as recited in claim 1, wherein the step of encapsulating partially flattens the bumps and forms a surface of the molding compound which forms a single flat surface with surfaces of the partially flattened bumps.

16. An encapsulated bumped die, comprising:

a die with an active top side and a bottom side opposite the top side, wherein the die comprises a plurality of bond pads on the top side of the die;

a plurality of partially flattened bumps wherein each partially flattened bump is connected to a bond pad of the plurality of bond pads;

a die attach pad connected to the bottom of the die; and

an encapsulant surrounding the sides of the die and at least partially surrounding the die attach pad and surrounding all of each partially flattened bump of the plurality of partially flattened bumps except for the flattened parts of the plurality of partially flattened bumps.

17. The encapsulated bumped die, as recited in claim 16, wherein the die attach pad is metal.

18. The encapsulated bumped die, as recited in claim 17, wherein the partially flattened bumps are solder.

19. The encapsulated bumped die, as recited in claim 18, further comprising adhesive connected between the die and the die attach pad.

20. The encapsulated bumped die, as recited in claim 19, wherein a surface of the encapsulant and surfaces of the plurality of partially flattened bumps form a single flat surface.