Adhesive and encapsulant material with fluxing properties

• US 5,128,746 A
• Filed: 09/27/1990
• Issued: 07/07/1992
• Est. Priority Date: 09/27/1990
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Papageorge, Marc V., Pennisi, Robert W.
• Primary Examiner(s): James, Andrew J.
• Assistant Examiner(s): CLARK, SHEILA V
• Application Number:
  US07/588,888
• Time in Patent Office: 649 Days
• Field of Search: 357/72, 357/80, 156/330, 156/331.8, 156/335, 106/123, 106/186, 106/189, 106/153, 106/136, 252/512, 528/8, 528/114
• US Class Current: 257/738
• CPC Class Codes: B23K 35/3613 Polymers, e.g. resins
• 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 2224/32225 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 2224/81191 wherein the bump connectors are disposed only on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/83192 wherein the layer connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 24/29 of an individual 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01016 Sulfur [S]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 Silver [Ag]
• CPC Class Codes: H01L 2924/01049 Indium [In]
• CPC Class Codes: H01L 2924/0105 Tin [Sn]
• CPC Class Codes: H01L 2924/01075 : Rhenium [Re]
• 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 2924/01322 : 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 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/351 : Thermal stress
• CPC Class Codes: H01L 2924/3512 : Cracking
• CPC Class Codes: H05K 2201/0145 : Polyester, e.g. polyethylene terephthalate [PET], polyethylene naphthalate [PEN]
• CPC Class Codes: H05K 2201/10674 : Flip chip
• CPC Class Codes: H05K 2201/10734 : Ball grid array [BGA]; Bump grid array
• CPC Class Codes: H05K 2201/10977 : Encapsulated connections
• CPC Class Codes: H05K 2203/1189 : Pressing leads, bumps or a die through an insulating layer
• CPC Class Codes: H05K 3/305 : Affixing by adhesive
• CPC Class Codes: H05K 3/3489 : Composition of fluxes; Methods of application thereof; Other methods of activating the contact surfaces
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

An adhesive material 120 including a fluxing agent is applied to either a substrate 100 having a metallization pattern 110 or a solder bumped electrical component 130. The component 130 is positioned on the substrate 110 and the solder bump 140 is reflowed. During the reflow step, the fluxing agent promotes adhesion of the solder 140 to the substrate metallization pattern 110, and the adhesive material 120 is cured to mechanically interconnect and encapsulate the substrate 110 to the component 130.

Claims

1. A thermally curable adhesive having a fluxing agent for use in reflow soldering an electrical component and a substrate, comprising an adhesive that removes oxide coatings from the electrical component or the substrate and at least partially cures when heated to soldering temperatures, said adhesive consisting essentially of a thermoset resin, a fluxing agent in an amount sufficient to remove said oxide coatings from said component or said substrate, and a curing agent that reacts with and cures the thermoset resin when the thermally curable adhesive is heated.

2. The adhesive of claim 1, wherein the thermoset resin is epoxy or polyester.

3. The adhesive of claim 1, wherein the fluxing agent comprises a compound having the formula:

##STR2## where R is an electron withdrawing group.

4. The fluxing agent of claim 3, wherein R is selected from the group consisting of fluorine, chlorine, bromine, iodine, sulfur, hydroxyl, nitrile, and benzyl.

5. The adhesive of claim 1, wherein the fluxing agent is malic acid.

6. The adhesive of claim 1, wherein the proportion of the fluxing agent in the adhesive ranges from about 0.1 to about 16 weight % of the adhesive.

7. An electrical component assembly, comprising;

an electrical component having a plurality of electrical terminations, each termination including a solder bump,

a component carrying substrate having a plurality of electrical terminations corresponding to the terminations of the electrical component,

a thermally curable adhesive material that removes oxide coatings from the component plurality of electrical terminations and the substrate plurality of electrical terminations when heated to soldering temperatures, comprising;

an epoxy resin,

a curing agent that reacts with and cures the epoxy resin when the thermally curable adhesive is heated, and

a fluxing agent in an amount sufficient to remove said oxide coatings from said component terminations or said substrate terminations,

the adhesive material disposed between and bonding the electrical component and the substrate, the solder bump being reflowed and electrically connecting the electrical component to the substrate.

8. The electrical component assembly of claim 7, wherein the fluxing agent comprises a compound having the formula:

##STR3## where R is an electron withdrawing group.

9. The fluxing agent of claim 8, wherein R is selected from the group consisting of fluorine, chlorine, bromine, iodine, sulfur, hydroxyl, nitrile, and benzyl.

10. The fluxing agent of claim 8, wherein the compound is malic acid.

11. The electrical component assembly of claim 7, wherein the proportion of the fluxing agent in the adhesive ranges from about 0.1 to about 16 weight % of the adhesive material.

12. The electrical component assembly of claim 7, wherein the component is an integrated circuit.