Underfill contacting stacking balls package fabrication method and structure

• US 8,633,598 B1
• Filed: 09/20/2011
• Issued: 01/21/2014
• Est. Priority Date: 09/20/2011
• Status: Active Grant

• Current Assignee: Amkor Technology Singapore Holding Pte., Ltd. (Amkor Technology Incorporated)
• Original Assignee: Amkor Technology Incorporated
• Inventors: St. Amand, Roger D.
• Primary Examiner(s): Clark, S. V.
• Application Number:
  US13/236,916
• Time in Patent Office: 854 Days
• Field of Search: 257/782, 257/783, 257/778, 257/686, 257/777, 257/701
• US Class Current: 257/778
• CPC Class Codes: H01L 21/4853 Connection or disconnection of other leads to or from a metallisation, e.g. pins, wires, bumps
• CPC Class Codes: H01L 21/563 Encapsulation of active face of flip-chip device, e.g. underfilling or underencapsulation of flip-chip, encapsulation preform on chip or mounting substrate
• CPC Class Codes: H01L 2224/131 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 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/81011 Chemical cleaning, e.g. etching, flux
• CPC Class Codes: H01L 2224/81192 wherein the bump connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/81815 Reflow soldering
• CPC Class Codes: H01L 2224/83102 using surface energy, e.g. capillary forces
• CPC Class Codes: H01L 2224/83855 Hardening the adhesive by curing, i.e. thermosetting
• CPC Class Codes: H01L 2224/92125 the second connecting process involving a layer connector
• CPC Class Codes: H01L 2225/1023 the support being an insulating substrate
• CPC Class Codes: H01L 2225/1058 Bump or bump-like electrical connections, e.g. balls, pillars, posts
• CPC Class Codes: H01L 2225/1082 for improving alignment between containers, e.g. interlocking features
• CPC Class Codes: H01L 23/28 Encapsulations, e.g. encapsulating layers, coatings, e.g. for protectionH01L23/552 takes precedence; insulating layers for contacts or interconnections H01L23/5329
• CPC Class Codes: H01L 23/3121 : a substrate forming part of the encapsulation
• CPC Class Codes: H01L 23/3135 : Double encapsulation or coating and encapsulation
• 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 24/16 : of an individual bump connector
• CPC Class Codes: H01L 24/17 : of a plurality of bump connectors
• 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 24/81 : using a bump connector
• CPC Class Codes: H01L 25/105 : the devices being of a type provided for in group H01L27/00
• 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 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/15331 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/181 : Encapsulation

Abstract

Stacking balls are formed on ball terminals prior to application of an underfill under a flip chip mounted electronic component. The underfill is then applied and directly contacts and at least partially encloses an inner row of the stacking balls closest to and directly adjacent the flip chip mounted electronic component. By forming the stacking balls prior to the application of the underfill, contamination of the ball terminals by the underfill is avoided. This allows the spacing between the ball terminals and the electronic component to be minimized.

Claims

1. An electronic component package comprising:

a substrate core comprising a first surface;

first traces coupled to the first surface of the substrate core, the first traces comprising flip chip terminals and ball terminals;

metallic studs coupled to the flip chip terminals;

stacking balls coupled to the ball terminals, wherein the metallic studs have a higher melting temperature than the stacking balls;

an electronic component coupled to the metallic studs; and

an underfill between the electronic component and the first surface of the substrate core, the underfill directly contacting at least some of the stacking balls.

2. The electronic component package of claim 1 wherein the metallic studs comprise copper.

3. The electronic component package of claim 2 wherein the stacking balls comprise solder.

4. The electronic component package of claim 1 wherein the electronic component comprises an active surface comprising bond pads thereon, the electronic component package further comprising:

metallic stud interconnects coupling the bond pads to the metallic studs.

5. The electronic component package of claim 4 wherein the underfill encloses the metallic studs and the metallic stud interconnects.

6. The electronic component package of claim 1 wherein the underfill directly contacts a lower stacking ball portion of a first stacking ball of the stacking balls, an upper stacking ball portion of the first stacking ball being exposed from the underfill.

7. The electronic component package of claim 6 wherein the underfill does not contact a second stacking ball of the stacking balls.

8. The electronic component package of claim 1 wherein the underfill tapers to become thinner as a lateral distance from the electronic component increases.

9. The electronic component package of claim 1 further comprising:

a package body enclosing the electronic component and the underfill; and

via apertures extending in the package body to expose the stacking balls.

10. An electronic component package comprising:

a substrate core comprising a first surface;

first traces coupled to the first surface of the substrate core, the first traces comprising a ball terminal and a flip chip terminal;

a metallic stud coupled to the flip chip terminal;

a first stacking ball coupled to the ball terminal, wherein the metallic stud has a higher melting temperature than the stacking ball;

an underfill directly contacting the first stacking ball;

a package body enclosing the underfill; and

a first via aperture extending entirely through the package body and partially into the underfill, the first via aperture exposing the first stacking ball.

11. The electronic component package of claim 10 wherein the package body comprises a principal surface, the first via aperture extending from the principal surface to the first stacking ball.

12. The electronic component package of claim 10 further comprising:

a second stacking ball; and

a second via aperture formed entirely within the package body, the second via aperture exposing the second stacking ball.

13. The electronic component package of claim 12 wherein the underfill does not contact the second stacking ball.

14. An electronic component package comprising:

a substrate core comprising a first surface;

first traces coupled to the first surface of the substrate core, the first traces comprising flip chip terminals and ball terminals;

stacking balls coupled to the ball terminals;

an electronic component coupled to the flip chip terminals by metallic studs, wherein the metallic studs have a higher melting temperature than the stacking balls; and

an underfill between the electronic component and the first surface of the substrate core, the underfill directly contacting an inner row of the stacking balls, wherein the underfill does not contact an outer row of the stacking balls, the outer row of the stacking balls being located at a greater lateral distance from the electronic component than the inner row of stacking balls.

15. The electronic component package of claim 14 wherein the underfill tapers to become thinner as a lateral distance from the electronic component increases.

16. The electronic component package of claim 14 further comprising:

a package body enclosing the underfill; and

a first via aperture extending entirely through the package body and partially into the underfill, the first via aperture exposing a stacking ball of the inner row of stacking balls.

17. The electronic component package of claim 16 further comprising:

a second via aperture formed entirely within the package body, the second via aperture exposing a stacking ball of the outer row of stacking balls.

18. The electronic component package of claim 14 wherein the underfill directly contacts lower stacking ball portions of the inner row of stacking balls, upper stacking ball portions of the inner row of stacking balls being exposed from the underfill.