Patent US4737208A successfully refreshed from Google Patents.
US4737208A
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Method of fabricating multilayer structures with nonplanar surfaces
Assignee: Nokia Bell Labs
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Filing: 1986-09-29
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Granted: 1988-04-12
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Expires: 2006-09-29
Abstract
Abstract Disclosed is a method for laminating multilayer structures with nonplanar surfaces such as structures which include cavity (20) formed therein. A conformal material (32), a release material (31), and an optional template (36) are provided over the structure prior to the lamination bonding operation. The conformal and release materials then fill the cavity during the bonding operation to prevent flow of adhesive (25 and 26) from between the layers into the cavity, and the template redistributes cavity edge stresses to minimize wire bonding pad deflections. The materials can then be removed for further processing of the multilayer structure.
Inventors
- 👤 Donald P. Bloechle
- 👤 Mohanan P. Kalliat
- 👤 William A. Mazeika
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:52
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/46; H05K3/4697; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H05K1/00; H05K1/18; H05K1/182; H05K2201/00; H05K2201/01; H05K2201/0104; H05K2201/0133; H05K2203/00; H05K2203/06; H05K2203/063; H05K3/4611; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24479; Y10T428/24488; Y10T428/24612; Y10T428/24752
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
95 words
A method of fabricating a multilayer structure which includes a recess defined by a nonplanar surface comprising the step of providing a flowable adhesive between the layers for bonding the layers together and characterized by the steps of: providing a release material and a flowable, conformal material thereon over the multilayer structure including the area over the recess; and applying heat and pressure to the structure sufficient to cause the conformal and release materials to fill the recess before the adhesive flows into the recess and thereby prevent the flow of adhesive into the recess.
Claim 2
Independent Claim
95 words
A method of fabricating a multilayer structure which includes a recess defined by a nonplanar surface comprising the step of providing a flowable adhesive between the layers for bonding the layers together and characterized by the steps of: providing a release material and a flowable, conformal material thereon over the multilayer structure including the area over the recess; and applying heat and pressure to the structure sufficient to cause the conformal and release materials to fill the recess before the adhesive flows into the recess and thereby prevent the flow of adhesive into the recess.
Claim 3
Dependent Claim
26 words
The method according to claim 1 wherein the recess is a cavity defined by the multiple layers which is suitable for providing a semiconductor chip therein.
Claim 4
Dependent Claim
18 words
The method according to claim 1 wherein the conformal material comprise a flowable rubber with a putty-like consistency.
Claim 5
Dependent Claim
30 words
The method according to claim 1 wherein the release material comprises a material with an elongation of at least 200 percent and a yield stress of less than 13.8 MPa.
Claim 6
Dependent Claim
45 words
The method according to claim 2 further characterized by the step of providing a template between the multilayer structure and release material in areas of the structure outside the cavity in order to distribute stresses away from the edges of the layers defining the cavity.
Claim 7
Dependent Claim
42 words
The method according to claim 1 wherein the heat is applied at a rate of 5°-30° C./minute to a peak temperature in the range 160°-190° C. for a period of 30-90 minutes, and the pressure applied is in the range 0.8-4.8 MPa.
Claim 8
Dependent Claim
26 words
The method according to claim 1 further comprising the step of lifting off the conformal and release materials subsequent to the application of heat and pressure.
Claim 9
Independent Claim
136 words
A method of fabricating a multilayer structure which includes a cavity defined by said layers suitable for providing a semiconductor chip therein, comprising the step of providing a flowable adhesive between the layers for bonding the layers together, and characterized by the steps of: providing over the multilayer structure including the area over the cavity, a first layer of a release material having an elongation of at least 200 percent and a yield stress of less than 13.8 MPa; providing over the release material a second layer of a conformal material comprising a flowable rubber with a putty-like consistency, and applying heat and pressure to the structure sufficient to cause the conformal and release materials to fill the cavity before the adhesive flows into the cavity and thereby prevent the flow of adhesive into the cavity.
Claim 10
Independent Claim
136 words
A method of fabricating a multilayer structure which includes a cavity defined by said layers suitable for providing a semiconductor chip therein, comprising the step of providing a flowable adhesive between the layers for bonding the layers together, and characterized by the steps of: providing over the multilayer structure including the area over the cavity, a first layer of a release material having an elongation of at least 200 percent and a yield stress of less than 13.8 MPa; providing over the release material a second layer of a conformal material comprising a flowable rubber with a putty-like consistency, and applying heat and pressure to the structure sufficient to cause the conformal and release materials to fill the cavity before the adhesive flows into the cavity and thereby prevent the flow of adhesive into the cavity.
Claim 11
Dependent Claim
24 words
The method according to claim 1 wherein the boundaries of the recess are defined by the layers and the adhesive extends to the boundaries.
Claim 12
Dependent Claim
21 words
The method according to claim 7 wherein the conformal and release materials are discarded after the fabrication of a single structure.
Claim 13
Dependent Claim
26 words
The method according to claim 1 wherein the release material and conformal material are provided as layers of uniform thickness over the area of the recess.
Claim 14
Dependent Claim
24 words
The method according to claim 8 wherein the adhesive extends to the boundaries of the cavity defined by said layers of the multilayer structure.
Claim 15
Dependent Claim
29 words
The methoding according to claim 8 further comprising the steps of lifting off the conformal and release layers and discarding said layers after the fabrication of a single structure.
Claim 16
Dependent Claim
26 words
The method according to claim 8 wherein the release material and conformal material are provided as layers of uniform thickness over the area of the cavity.
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) | 1991-04-12 | 1991-10-12 | 1992-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-12 | 1995-10-12 | 1996-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-12 | 1999-10-12 | 2000-04-12 | $7700.00 | Window Closed / Lapsed |