US3742181A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for heatbonding in a local area using combined heating techniques
Assignee: Argus International
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Filing: 1971-02-25
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Granted: 1973-06-26
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Expires: 1991-02-25
Abstract
Abstract Apparatus for joining a dielectric or semi-conductive element to a metallic layer employing a combination of heating techniques. The substrate upon which the metallic layer is already deposited is heated to a ''''background'''' temperature substantially below the temperature required for bonding, to reduce the local temperature rise required to perform the bond and to reduce the shock experienced by the substrate due to thermal gradients which occur during the bonding cycle. The bonding energy in the form of radiant energy, is focussed upon the side of the substrate opposite to the side on which the bond is to be formed, and in the region of said bond, and is at a level sufficient to heat the interface to a temperature greater than the bond point to enable the two materials to flow together and form the bond. Focussing the bonding energy upon the opposite surface of the substrate causes the bonding surface of the element to be hotter than the bulk of the element thus causing a thermal gradient across the element such that the top surface of the semiconductor element is much cooler than the under surface, providing an enhanced margin of safety in preventing thermal damage to active zones or thermally sensitive regions in the element being bonded. The dielectric or semi-conductive element being bonded to the metal layer is often scrubbed across the metal layer to enhance formation of the bond by removing oxide coatings which may have formed on the element and which would otherwise reduce the effectiveness of the bond.
Inventors
- 👤 B Costello
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:49
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0446; B; B23; B23K; B23K1/00; B23K1/005; B23K1/0053; B23K20/00; B23K20/02; B23K20/023; B23K20/025
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
15 words
The apparatus of claim 1 wherein said outlet port is smaller than said inlet port.
Claim 2
Dependent Claim
49 words
The apparatus of claim 1 further comprising a holding chuck for positioning said second member upon said first member; means for moving said holding chuck in a reciprocating manner for scrubbing said first member across said second member to facilitate removal of any oxide coatings and to facilitate wetting.
Claim 3
Dependent Claim
38 words
The apparatus of claim 3 further comprising vacuum means coupled to said holding chuck for holding said first member to said holding chuck and thereby facilitating pick up and positioning of said first member upon said second member.
Claim 4
Dependent Claim
374 words
Apparatus for forming an alloy bond between a non-metallic wafer and a metallic layer comprising: a first supporting plate; said first plate having an opening communicating with the top and bottom surfaces of said plate to provide an inlet port in said bottom surface and an ouTlet port in said top surface; the interior surface of said opening being highly reflective to infrared radiation; infrared energy means comprising: a source of infrared energy positioned beneath the bottom surface of said plate; a reflector having a highly reflective concave surface positioned to reflect direct infrared rays reflected by said concave surface originating from said energy source toward said inlet port and being adapted to focus said reflected rays in the immediate region of said outlet port; said interior surface of said opening forming a kaleidoscopic cavity to reflect infrared rays impinging upon said interior surface and substantially uniformly distribute rays reflected by said interior surface across the outlet port; a second non-metallic plate being positioned upon said supporting plate top surface and above said outlet port; an elongated light transmissive rod having input and output ends; said rod extending through the opening in said first and second plate and having its output end immediately beneath the metallic layer supported by said second plate; said second plate having a central opening; second infrared energy means comprising: a second infrared energy source positioned beneath the bottom surface of said first plate; and a second reflector having a second concave surface for focusing infrared rays originating from said second energy source, reflected by said second reflector means, upon the input end of said light transmissive rod; said light transmissive rod being adapted to cause infrared radiation impinging upon said input end to be internally reflected and emitted at said output end whereby the infrared rays emitted from said output end are substantially uniformly distributed over the region confronting the output end to heat the elements being bonded to a first temperature level sufficient to form an alloy bond between the members being joined; said first infrared energy means being adapted to raise the temperature of the members positioned above said outlet opening to a level lower than said first temperature level and insufficient to form said alloy bond.
Claim 5
Dependent Claim
48 words
The apparatus of claim 5 further comprising heat sensing means positioned adjacent said wafer; control means coupled to said sensing means for regulating the output of said first energy source and thereby preventing the thermal energy generated by said first energy means from exceeding said second temperature level.
Claim 6
Dependent Claim
14 words
The apparatus of claim 6 wherein said heat sensing means is an infrared detector.
Claim 7
Dependent Claim
27 words
The apparatus of claim 6 wherein said control means is further comprised of means for energizing said second energy source when said second temperature level is reached.
Claim 8
Dependent Claim
37 words
The apparatus of claim 5 wherein said second plate is a quartz plate having projections upon its upper surface for supporting said metallic layer and reducing the surface contact between said second plate and said metallic layer.
Claim 9
Dependent Claim
234 words
Apparatus for forming an alloy bond between a non-metallic wafer and a metallic layer comprising: a first supporting plate, said first plate having an opening communicating with the top and bottom surfaces of said plate to provide an inlet port in said bottom surface and an outlet plate in said top surface above which the members to be joined are positioned; means for heating said plate to a temperature level insufficient to alloy bond said wafer and said metallic layer; an elongated light transmissive rod having input and output ends; said rod positioned extending through the opening in said plate and having its output end immediately beneath the metallic layer supported by said plate; said plate having a central opening; infrared energy means comprising: a first infrared energy source positioned beneath the bottom surface of said plate; and a reflector having a concave surface for focusing infrared rays originating from said energy source, reflected by said reflector means, upon the input end of said light transmissive rod; said light transmissive rod being adapted to cause infrared radiation impinging upon said input end to be internally reflected and emitted at said output end whereby the infrared rays emitted from said output end are substantially uniformly distributed over the region confronting the output end to heat the elements being bonded to a first temperature level sufficient to form an alloy bond between the members being joined.
Claim 10
Dependent Claim
186 words
Apparatus for heat bonding a surface of a first member to a surface of a second larger member comprising: a supporting structure for supporting said second member on the top surface thereof; said first member being positioned on the top surface of said second member; said structure having an opening communicating with its top and bottom surfaces to provide an inlet port in said bottom surface and an outlet port in said top surface; said second member being positioned above said opening; a radiant energy source positioned to direct radiation toward said inlet port in such a manner that a substantial portion of said radiation passes through said outlet port; means for heating said supporting structure and said members to a temperature level insufficient to cause said bonding to occur; said radiant energy source cooperating with said opening to locally heat only the interface, between said members, positioned immediately above said outlet port to a second temperature level higher than said first temperature level and sufficient to form a bond between said members while the remainder of said second member is maintained at said lower temperature.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |