Title: Solid state bonding process employing the isothermal solidification of a liquid interface

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1. An improved system for bonding selected metals comprising:

arranging an interliner metal layer between a first and a second layer, said interliner layer having a lower initial melting temperature than either the first or second layers and being heat diffusible with at least one of said layers to form a ductile alloy having a relatively higher melting temperature.

solid state pressure bonding said interliner and said layers to form a composite material, and

post bond heating of said metal layers at a temperature above said initial melting temperature of said interliner layer and below said relatively higher melting temperature of said alloy for sufficient time to melt said interliner and initiate diffusion of said intermediate layer meterial with at least said one of the two layers to form a layer of said new alloy of higher melting point and to solidify said new alloy layer for securely bonding said first and second layers of metal together.

2. An improved system for bonding as set forth in claim 1 wherein said first layer is silver or a high silver alloy and said second layer is copper or a high copper alloy.

3. An improved system for bonding as set forth in claim 2 wherein the composition by weight of said interliner is 52 percent silver, 16 percent copper, 15.5 percent zinc, and 16.5 percent cadmium.

4. An improved system for bonding as set forth in claim 2 wherein the composition by weight of said interliner is 72 percent silver and 28 percent copper.

5. An improved system for bonding a first layer of silver or silver alloy component to a second layer of copper or copper component to a third layer of a high work hardening component comprising:

arranging an interliner metal layer between the first and the second layer, said interliner layer having a lower initial melting temperature than any of the layers and being heat diffusible with at least one of said adjacent layers to form a ductile alloy having a relatively higher melting temperature,

solid state pressure bonding said interliner and said layers to form a composite material, and

post bond heating of said metal layers at a temperature above the recrystallization temperature of said high work hardening layer and initial melting temperature of said interliner layer and below said relatively higher melting temperature of said alloy for sufficient time to recrystallize said work hardening layer and to melt said interliner and initiate diffusion of said interliner layer material with at least one of the two adjacent layers to form a layer of said new alloy of higher melting point and to solidify said new alloy layer for securely bonding said layers of metal together.

6. An improved system for bonding as set forth in claim 5 wherein the third layer of a high work hardening component is selected from a group cnsisting of low carbon steel, nickel, monel, and ferritic stainless steel.

Other info:

Inventors: Lattari, Pasquale R. (Attleboro, MA, US)
Redfield, Carl (North Attleboro, MA, US)

Application Number: 554383
Filing Date: 1975-03-03
Publication_date: 1976-02-03
Assignee: Texas Instruments Incorporated (Dallas, TX)
Primary Class(es): 228/115 228/175, 228/190, 228/194, 228/262.61
Other Classes:
US Patent Ref:

2845698	Aug, 1958	Giovannucci et al.	228/263.
3397445	Aug, 1968	Ulmer et al.	228/263.
3496630	Feb, 1970	Duff et al.	228/263.
3668758	Jun, 1972	Krock et al.	228/193.
3678570	Jul, 1972	Paulonis et al.	228/194.

Other Refs:
Primary Examiner: Whitehead, Harold D.
Assistant Examiner: Ramsey, K. J.
Attorney: Haug; John A., McAndrews; James P., Baumann; Russell E.