Directing the flow of underfill materials using magnetic particles

• US 8,009,442 B2
• Filed: 12/28/2007
• Issued: 08/30/2011
• Est. Priority Date: 12/28/2007
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Chan, Wendy, Arana, Leonel R., Manepalli, Rahul N., Lehman, Stephen E. Jr.
• Primary Examiner(s): Chen; Xiaoliang
• Application Number:
  US11/966,940
• Publication Number:
  US 20090168390A1
• Time in Patent Office: 1,341 Days
• Field of Search: 361/820, 361/305, 298/32, 438/612, 438/106, 438/120, 257/728, 257/787
• US Class Current: 361/820
• 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 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/2936 Iron [Fe] as principal constituent
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73203 Bump and layer connectors
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/83 using a layer connector
• CPC Class Codes: H01L 2224/831 the layer connector being supplied to the parts to be connected in the bonding apparatus
• CPC Class Codes: H01L 2224/92125 the second connecting process involving a layer connector
• CPC Class Codes: H01L 24/83 using a layer connector
• 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 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/0665 Epoxy resin
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.

Abstract

Electronic devices and methods for fabricating electronic devices are described. One method includes providing a substrate and a die, and coupling the die to the substrate, wherein a gap remains between the die and the substrate. The method also includes placing an underfill material on the substrate and delivering at least part of the underfill material into the gap. The method also includes controlling the flow of the underfill material in the gap using magnetic force. Other embodiments are described and claimed.

Claims

1. A method comprising:

providing a semiconductor die and a substrate;

coupling the semiconductor die to the substrate, wherein a gap remains between the semiconductor die and the substrate, wherein an open region extends laterally outward on the substrate on four sides of the gap, wherein the open region is not covered by the semiconductor die;

placing an underfill material on the substrate, the underfill material comprising a polymer material and magnetic particles;

positioning at least part of the underfill material in the gap;

controlling the positioning of the underfill material using magnetic force, wherein the controlling the positioning includes controlling the flow of the underfill material so that the flow of the underfill material in the open region on the substrate is controlled by the magnetic force;

wherein the flow of the underfill material into the open region is controlled so that the underfill material extends into the open region on the four sides of the gap on the substrate, wherein the underfill material extends no greater than 1 mm into the open region on the substrate on each of the four sides; and

solidifying the polymeric material.

2. The method of claim 1, wherein the magnetic particles include an electrically insulating layer thereon.

3. The method of claim 1, wherein the magnetic particles include a alkyl surface layer thereon.

4. The method of claim 1, wherein the underfill material further comprises silica particles.

5. The method of claim 1, wherein the controlling the positioning of the underfill material using magnetic force comprises applying a non-uniform magnetic field to the underfill material.

6. A method comprising:

providing a first body and a second body;

coupling the first body to the second body, wherein a gap remains between the first body and the second body, wherein an open region extends laterally outward on the second body on four sides of the gap, the open region not covered by the first body;

placing an underfill material on the second body;

delivering a flow of at least part of the underfill material into the gap; and

controlling the flow of the underfill material using magnetic force, wherein the controlling the flow includes controlling the flow of the underfill material so that the underfill material extends into the open region on the four sides of the gap on the second body, wherein the underfill material extends no greater than 1 mm into the open region on the second body on each of the four sides.

7. The method of claim 6, wherein the placing the underfill material on the second body comprises depositing a material comprising a polymer and magnetic particles adjacent to the gap, and wherein the controlling the flow of the underfill material using magnetic force comprises applying a magnetic field in at least one direction that causes the underfill material to be drawn into the gap.

8. The method of claim 6, wherein the placing the underfill material on the second body includes placing a material comprising a polymer epoxy and magnetic particles on the second body.

9. The method of claim 6, further comprising curing the polymer epoxy.

10. The method of claim 6, wherein the placing the underfill material on the second body includes placing a material comprising a polymer epoxy, magnetic particles, and silica particles on the second body.

11. The method of claim 6, wherein the controlling the flow of the underfill material using magnetic force comprises applying a static magnetic field to the underfill material.

12. The method of claim 6, wherein the controlling the flow of the underfill material using magnetic force comprises applying a non-uniform magnetic field to the underfill material.

13. The method of claim 6, wherein the controlling the flow of the underfill material using magnetic force comprises using an electromagnet to generate the magnetic force.

14. The method of claim 6, wherein the coupling the first body to the second body including coupling the first body to the second body through a plurality of electrically conductive bumps positioned between the first body and the second body.

15. The method of claim 6, wherein the first body is a semiconductor die and the second body is a substrate.