Methods of making and using freestanding reactive multilayer foils

• US 20030164289A1
• Filed: 09/20/2002
• Published: 09/04/2003
• Est. Priority Date: 05/02/2000
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Knio, Omar, Weihs, Timothy P., Reiss, Michael, Feldmesser, Howard, Hufnagel, Todd, van Heerden, David, Swiston, Albert Joseph Jr.
• Granted Patent: US 6,991,856 B2
• Time in Patent Office: Days
• US Class Current: 204/192.12
• CPC Class Codes: B23K 1/0006 Exothermic brazing
• CPC Class Codes: B23K 20/00 Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
• CPC Class Codes: B23K 20/06 by means of high energy impulses, e.g. magnetic energy
• CPC Class Codes: B23K 20/08 Explosive welding
• CPC Class Codes: B23K 20/165 involving an exothermic reaction of the interposed material
• CPC Class Codes: B23K 28/00 Welding or cutting not covered by any of the preceding groups, e.g. electrolytic welding
• CPC Class Codes: B23K 35/0233 Sheets, foils B23K35/0244 takes precedence
• CPC Class Codes: B23K 35/0238 layered
• CPC Class Codes: B23K 35/34 comprising compounds which yield metals when heated
• CPC Class Codes: B32B 15/01 all layers being exclusively metallic making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00
• CPC Class Codes: B32B 15/017 one layer being formed of aluminium or an aluminium alloy, another layer being formed of an alloy based on a non ferrous metal other than aluminium
• CPC Class Codes: C06B 21/0083 Treatment of solid structures, e.g. for coating or impregnating with a modifier compositions therefor C06B23/00
• CPC Class Codes: C06B 45/14 a layer or zone containing an inorganic explosive or an inorganic explosive or an inorganic thermic component
• CPC Class Codes: C21D 2211/008 Martensite
• CPC Class Codes: C23C 14/14 Metallic material, boron or silicon
• CPC Class Codes: F24V 30/00 Apparatus or devices using heat produced by exothermal chemical reactions other than combustion
• CPC Class Codes: H05K 2203/0405 Solder foil, tape or wire
• CPC Class Codes: H05K 2203/1163 Chemical reaction, e.g. heating solder by exothermic reaction
• CPC Class Codes: H05K 3/3463 Solder compositions in relation to features of the printed circuit board or the mounting process
• CPC Class Codes: H05K 3/3494 Heating methods for reflowing of solder using integral heating means H05K1/0212
• CPC Class Codes: Y10S 228/902 : using flame
• CPC Class Codes: Y10S 428/94 : Pressure bonding, e.g. explosive
• CPC Class Codes: Y10T 29/301 : Method
• CPC Class Codes: Y10T 29/302 : Clad or other composite foil or thin metal making
• CPC Class Codes: Y10T 29/308 : Using transitory material
• CPC Class Codes: Y10T 29/49826 : Assembling or joining
• CPC Class Codes: Y10T 428/12028 : Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
• CPC Class Codes: Y10T 428/12063 : Nonparticulate metal component
• CPC Class Codes: Y10T 428/12069 : Plural nonparticulate metal components
• CPC Class Codes: Y10T 428/12076 : Next to each other
• CPC Class Codes: Y10T 428/1209 : Plural particulate metal components
• CPC Class Codes: Y10T 428/12229 : Intermediate article [e.g., blank, etc.]
• CPC Class Codes: Y10T 428/12361 : having aperture or cut
• CPC Class Codes: Y10T 428/12438 : Composite
• CPC Class Codes: Y10T 428/12451 : Macroscopically anomalous interface between layers
• CPC Class Codes: Y10T 428/12493 : Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
• CPC Class Codes: Y10T 428/1259 : Oxide
• CPC Class Codes: Y10T 428/12632 : Four or more distinct components with alternate recurrence of each type component
• CPC Class Codes: Y10T 428/1275 : Next to Group VIII or IB metal-base component
• CPC Class Codes: Y10T 428/12819 : Group VB metal-base component
• CPC Class Codes: Y10T 428/12903 : Cu-base component
• CPC Class Codes: Y10T 428/12944 : Ni-base component

Abstract

Reactive foils and their uses are provided as localized heat sources useful, for example, in ignition, joining and propulsion. An improved reactive foil is preferably a freestanding multilayered foil structure made up of alternating layers selected from materials that will react with one another in an exothermic and self-propagating reaction. Upon reacting, this foil supplies highly localized heat energy that may be applied, for example, to joining layers, or directly to bulk materials that are to be joined. This foil heat-source allows rapid bonding to occur at room temperature in virtually any environment (e.g., air, vacuum, water, etc.). If a joining material is used, the foil reaction will supply enough heat to melt or soften the joining material, which upon cooling will form a strong bond, joining two or more bulk materials. If no joining material is used, the foil reaction supplies heat directly to at least two bulk materials, melting or softening a portion of each bulk, which upon cooling, form a strong bond. Additionally, the foil may be designed with openings that allow extrusion of the joining (or bulk) material through the foil to enhance bonding.

Claims

1. A method of making a freestanding reactive multilayer foil composed of a plurality of alternating layers that can react exothermically, comprising the steps of:

providing a substrate;

vapor depositing the alternating layers on the substrate to form the reactive multilayer foil; and

separating the multilayer foil from the substrate.

2. The method of claim 1 wherein the substrate has sufficient adherence to the deposited layers to retain the layers during deposition but insufficient adherence to prevent removal of the multilayer foil after deposition.

3. The method of claim 1 wherein the layers comprise one or more layers of aluminum, and at least one of the layers of aluminum is deposited in contact with the substrate.

4. The method of claim 3 wherein the substrate comprises silicon.

5. The method of claim 1 wherein the substrate comprises a coating of a release material or a coating of an adhesion material.

6. The method of claim 1 wherein the substrate comprises a removable sacrificial layer.

7. The method of claim 1 wherein the substrate comprises a removable sacrificial layer of copper, brass or photoresist.

8. The method of claim 1 wherein the vapor depositing comprises physical vapor deposition.

9. The method of claim 1 wherein the vapor depositing comprises magnetron sputtering or electron beam evaporation.

10. The method of claim 1 wherein the substrate is cooled during the vapor depositing.

11. The method of claim 1 wherein the layers are deposited to form a multilayer foil having a thickness in the range 50 μ

m-1 cm.

12. The method of claim 1 wherein the vapor depositing is under conditions chosen to minimize stress in the deposited layers.

13. A method of bonding a first body to a second body comprising the steps of:

disposing between the first body and the second body, a freestanding reactive multilayer foil;

pressing the bodies together against the foil; and

igniting the reactive foil.

14. The method of claim 13 wherein at least one of the bodies is a semiconductor or microelectronic device.

15. The method of claim 13 wherein the reactive multilayer foil has a thickness in excess of 10 μ

m.

16. The method of claim 13 wherein the bodies have coefficients of thermal expansion differing by at least 1 μ

m/m/°

C.

17. The method of claim 13 wherein the first body comprises metal and the second body comprises ceramic material.

18. The method of claim 13 wherein at least one of the two bodies comprises a metallic glass.

19. The product made by the method of claim 13.

20. A reactive multilayer foil comprising:

a foil composed of alternating layers that react exothermically, wherein the foil includes a plurality of openings through the foil.

21. A reactive multilayer foil according to claim 20 wherein the openings are filled with joining material, propellant, or material that changes or reacts on heating.

22. A reactive multilayer foil according to claim 20 wherein the openings are periodically arranged across the area of the foil.

23. A method of making a reactive multilayer foil comprising the steps of:

providing a substrate having a surface including a plurality of preformed openings, bumps, or particles of thickness or depth similar to or greater than the multilayer foil to be deposited;

depositing on the surface a plurality of layers to form the reactive multilayer foil; and

separating the multilayer foil from the substrate.

24. A method of making a reactive multilayer foil comprising the steps of:

providing a flat substrate;

depositing on the substrate a plurality of layers to form a reactive multilayer foil;

depositing a masking layer on top of the reactive foil;

patterning the masking layer with a plurality of holes;

etching the reactive foil through the holes; and

separating the multilayer foil from the substrate.

25. A method of making a reactive multilayer foil comprising the steps of:

providing a flat substrate;

depositing on the substrate a plurality of layers to form a reactive multilayer foil; and

mechanically pressing a plurality of holes into the reactive foil.

26. A method of making a reactive multilayer foil comprising the steps of:

making a reactive multilayer foil having a plurality of openings through the foil, and

filling the openings in the multilayer foil with joining material, propellant, or material that will change or react on heating when the reactive foil is ignited.

27. A method of bonding a first body to a second body comprising the steps of:

disposing between the first body and the second body, a reactive multilayer foil and at least one joining material, the reactive multilayer foil having a plurality of openings through the thickness of the foil;

pressing the bodies together against the foil and the joining material; and

igniting the reactive foil to heat the joining material and permit the melted or softened joining material to flow through the openings to join the first and second bodies.

28. The method of claim 27 wherein at least one of first body or the second body comprise a semiconductor or a microelectronic device.

29. The method of claim 27 wherein the first body and the second body have CTEs that differ by more than about 1 μ

m/m/°

C.

30. The method of claim 27 wherein at least one of the two bodies comprises a metallic glass.

31. The product made by the method of claim 27.

32. The product made by the method of claim 28.

33. The product made by the method of claim 29.

34. A composite reactive multilayer foil comprising:

at least one first set of reactive layers; and

at least one second set of reactive layers in thermal contact with the first set, the layers of the first set having thicknesses which are relatively larger than those of the second set, whereby the layers of the second set, upon ignition, ignite the thicker layers of the first set.

35. A composite reactive multilayer foil comprising:

a first set of reactive layers; and

a second set of reactive layers in thermal contact with the first set, the layers of the first set having compositions which are relatively more reactive than the second set, whereby the layers of the first set, upon ignition, ignite the less reactive layers of the second set.

36. A reactive multilayer foil comprising:

a multilayer foil having an area composed of at least two different regions, one or more first regions composed of layers that can react exothermically to form electrically conductive material and one or more second regions which are non-conductive or react to form nonconductive material.

37. A method of connecting a semiconductor or microelectronic device having one or more electrical contacts to a substrate having one or more receiving contacts, comprising the steps of:

disposing between the device and the substrate a reactive multilayer foil composed of one or more first regions that can react exothermically to form electrically conductive regions and one or more second regions which are non-conductive or react to form non-conductive material;

registering the contacts of the device, the contacts of the substrate and the first regions of the foil,

pressing the device and the substrate together against the foil; and

igniting the foil.

38. A method for bonding a first body to a second body comprising the steps of:

disposing between the first body and the second body, a reactive multilayer foil comprising a plurality of successive exothermic reactive layers that react to form a joining material;

pressing the bodies together against the foil; and

igniting the foil.

39. The method of claim 38 wherein at least one of the first and second bodies comprise metallic glass.

40. The method of claim 38 wherein the reactive multilayer foil comprises alternate layers of alloys that, after reaction and cooling, comprise amorphous material.

41. The method of claim 38 wherein the reactive multilayer foil comprises alternate layers that, after reaction and cooling, are fully or partially quasicrystalline.

42. The method of claim 38 wherein the reactive multilayer foil comprises alternate layers of an alloy comprising Ni or Cu, an alloy comprising Ti, Zr, or Hf, and an alloy containing Al.

43. A method of bonding a first body to a second comprising the steps of:

disposing between the first body and the second body, a freestanding reactive multilayer foil and at least one layer of joining material;

pressing the bodies together against the foil and joining material; and

igniting the reactive foil to melt or soften the joining material.

44. The method of claim 43 wherein the joining material is coated on the foil.

45. The method of claim 43 wherein the joining material is freestanding.

46. The method of claim 43 wherein the joining material comprises a metallic glass.

47. A bonded structure comprising:

a first body;

a second body bonded to the first body by a joining region, the joining region comprising a reacted multilayer structure including a periodic array of openings therethrough, the structure embedded in a matrix of joining material extending through the openings to join the first body and the second body.

48. A method of bonding a first body to a second body comprising the steps of:

disposing between the first body and the second body, a reactive multilayer foil and at least one layer of joining material;

pressing the bodies together against the layer of joining material and the foil; and

igniting the reactive foil to melt or soften the joining material.

49. The method of claim 48 wherein the reactive multilayer foil has a plurality of openings through the thickness of the foil to permit the heated joining material to flow through the foil.

50. The method of claim 48 wherein the reactive multilayer foil forms cracks through the foil after ignition to permit the heated joining material to flow through the foil.

51. The method of claim 48 wherein the reactive multilayer foil has scoring or a plurality of openings to facilitate cracking after ignition.

52. The method of claim 48 further including the step of placing the foil under tensile force to facilitate cracking of the foil and extrusion out of the joint interface after ignition.

53. The method of claim 48 further including the steps of pressing the two bodies together against the joining material and the foil with sufficient pressure to extrude a portion of the foil reaction products from between the bodies after ignition.

54. The method of claim 48 wherein the joining material when heated by the reactive foil has sufficient viscosity to facilitate extrusion of foil reaction products from between the bodies after ignition.

55. The method of claim 48 wherein the layer of joining material includes dispersed particles to increase the viscosity of the material when molten.

56. The method of claim 48 further including the step of preheating the joining material prior to igniting the reactive foil.

57. The method of claim 48 wherein the joining material is heated and cooled with sufficient rapidity to form an amorphous material.

58. The method of claim 48 wherein the joining material comprises an amorphous material.

59. The method of claim 58 wherein the first and second bodies are pressed against the joining material and foil with a pressure greater than about 10 MPA.

60. The method of claim 58 wherein the reactive foil has thickness in excess of about 100 micrometers.

61. The method of claim 58 wherein the reactive foil generates an energy density greater than about 70 J/cm².

62. A layered structure for bonding together two bodies comprising a reactive multilayer foil and a layer of joining material.

63. The structure of claim 62 wherein the reactive multilayer foil is scored or perforated to facilitate cracking after ignition.

64. The structure of claim 62 wherein the reactive multilayer foil has a plurality of openings for the passage of the joining material after heating.

65. The structure of claim 62 wherein the joining material comprises an amorphous material.

66. The structure of claim 62 wherein the joining material comprises a metallic glass.

67. The structure of claim 62 wherein the joining material comprises a crystalline metallic material that cools to a material comprising amorphous material after heating by ignition of the reactive foil.

68. The structure of claim 62 wherein the joining material comprises a crystalline metallic material that cools to a fully or partially quasicrystalline state after heating by the reactive foil.