Magneto-active adhesive systems

• US 20050274454A1
• Filed: 06/08/2005
• Published: 12/15/2005
• Est. Priority Date: 06/09/2004
• Status: Abandoned Application

• Current Assignee: Entegris Incorporated
• Original Assignee: Entegris Incorporated
• Inventors: Extrand, Charles W.
• Application Number:
  US11/148,950
• Publication Number:
  US 20050274454A1
• Time in Patent Office: Days
• US Class Current: 156/272.400
• CPC Class Codes: B29C 65/3612 comprising fillers
• CPC Class Codes: B29C 65/368 with a polymer coating
• CPC Class Codes: B29C 65/3696 with a coating
• CPC Class Codes: B29C 65/4875 being spherical, e.g. particles or powders
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/41 Joining substantially flat articles B29C66/47 and subgroups take precedence; Making flat seams in tubular or hollow articles B29C66/51 and subgroups take precedence
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29K 2023/00 Use of polyalkenes or derivatives thereof as moulding material
• CPC Class Codes: B29K 2023/06 PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/12 PP, i.e. polypropylene
• CPC Class Codes: B29K 2027/12 containing fluorine
• CPC Class Codes: B29K 2033/12 Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B29K 2055/02 ABS polymers, i.e. acrylonitrile-butadiene-styrene polymers
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2069/00 Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2071/00 Use of polyethers , e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2075/00 Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2077/00 Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2079/085 Thermoplastic polyimides, e.g. polyesterimides, PEI, i.e. polyetherimides, or polyamideimides; Derivatives thereof
• CPC Class Codes: B29K 2081/04 Polysulfides, e.g. PPS, i.e. polyphenylene sulfide or derivatives thereof
• CPC Class Codes: B29K 2081/06 : PSU, i.e. polysulfones; PES, i.e. polyethersulfones or derivatives thereof
• CPC Class Codes: B29L 2017/006 : Memory cards, chip cards
• CPC Class Codes: C09J 11/04 : inorganic
• CPC Class Codes: C09J 5/00 : Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
• CPC Class Codes: C09J 9/00 : Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks C09J7/00 takes precedence
• CPC Class Codes: H01L 2224/83222 : Induction heating, i.e. eddy currents
• CPC Class Codes: Y10T 428/25 : Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles

Abstract

A magneto-active adhesive and method of adhesive bonding by magnetic field. The method includes steps of providing at least two adherends to be bonded, providing a magneto-active adhesive system between the at least two adherends, the magneto-active adhesive system comprising a plurality of magnetic particles and an adhesive; and applying a non-cyclically varying magnetic field or a cyclically varying magnetic field induced by an alternating current having a frequency of less than 100 hz to the magneto-active adhesive system to change the adhesion of the magneto-active adhesive system to at least one of the adherends. Various carriers for microelectronic devices including magneto-active adhesive contact surfaces are also described within the scope of the invention.

Claims

1. A method of adhesive bonding by magnetic field, comprising the steps of:

(a) providing at least two adherends to be bonded;

(b) providing a magneto-active adhesive system between the at least two adherends, the magneto-active adhesive system comprising a plurality of magnetic particles and an adhesive; and

(c) applying a non-cyclically varying magnetic field or a cyclically varying magnetic field induced by an alternating current having a frequency of less than 100 hz to the magneto-active adhesive system to change the adhesion of the magneto-active adhesive system to at least one of the adherends.

2. The method of claim 1, further including the step of selecting one of the adherends from the group consisting of a matrix tray, a read/write head tray, a chip tray, a carrier tape, a carrier sheet, and a film frame.

3. A magneto-active adhesive system comprising:

a pair of adherends;

a layer of magneto-active adhesive confronting each of the adherends, the magneto-active adhesive comprising a-multiplicity of magnetic particles in an adhesive binder; and

means for activating the magneto-active adhesive to adhere the adherends together.

4. The system of claim 3, wherein one of the adherends comprises a plurality of semiconductor components, microelectronic components, or combinations thereof, and the other of the pair of adherends is selected from the group consisting of a matrix tray, a read/write head tray, a chip tray, a carrier tape, a carrier sheet, and a film frame.

5. The system of claim 4, wherein at least one of the adherends is made of a material selected from the group consisting of acrylonitrile-butadiene-styrene, polycarbonate, urethane, polyphenylene sulfide, polystyrene, polymethyl methacrylate, polyetherketone, polyetheretherketone, polyetherketoneketone, polyether imide, polysulfone, styrene acrylonitrile, polyethylene, polypropylene, fluoropolymer, polyolefin, nylon, and combinations thereof.

6. The system of claim 3, wherein the magneto-active adhesive includes a carrier fluid, the carrier fluid and the multiplicity of magnetic particles together constituting a magnetorheological fluid.

7. The system of claim 6, wherein the number average particle size of the magnetic particles is between 0.1 and 1000 microns.

8. The system of claim 3, wherein the magneto-active adhesive includes a carrier fluid and the adhesive binder includes a cross-linked polymer network, the carrier fluid, the adhesive, and the plurality of magnetic particles together constituting a ferrogel.

9. The system of claim 7 wherein the number average particle size of the magnetic particles is between about 1 and 1000 nm.

10. The system of claim 3, wherein the magnetic particles comprise magnetocaloric particles.

11. The system of claim 10 wherein the magnetocaloric particles are selected from the group consisting of Gd, Gd₅Si₂Ge₂, MnAs, La(Fe_0.88Si_0.12)₁₃, and La(Fe_0.88Si_0.12)₁₃H_1.0 particles.

12. The system of claim 3, wherein the magnetic particles comprise magnetic inductive particles and the adhesive binder comprises a shape-memory polymer.

13. A carrier for a microelectronic component comprising:

a body portion made from plastic material; and

an magneto-active adhesive component contact surface comprising a layer of magneto-active adhesive on the body portion for retaining the microelectronic component on the carrier.

14. The carrier of claim 13, wherein the magneto-active adhesive comprises a multiplicity of magnetic particles in an adhesive binder.

15. The carrier of claim 14, wherein the magneto-active adhesive comprises magnetorheological fluid.

16. The carrier of claim 14, wherein the magneto-active adhesive comprises a ferrogel.

17. The carrier of claim 14, wherein the magneto-active adhesive includes magnetocaloric particles.

18. The carrier of claim 14, wherein the magneto-active adhesive comprises a crystallizable polymeric adhesive.

19. The carrier of claim 14, wherein the magneto-active adhesive comprises a shape-memory polymer.

20. The carrier of claim 14, wherein the magneto-active adhesive comprises a mulitplicity of encapsulated magnetic particles.