Cover for an optical device and method for making same

• US 6,428,650 B1
• Filed: 08/07/2000
• Issued: 08/06/2002
• Est. Priority Date: 06/23/1998
• Status: Expired due to Fees

• Current Assignee: Amerasia International Technology, Inc.
• Original Assignee: Amerasia International Technology, Inc.
• Inventors: Chung, Kevin Kwong-Tai
• Primary Examiner(s): LORENGO, JERRY A
• Application Number:
  US09/633,791
• Time in Patent Office: 729 Days
• Field of Search: 156/235, 156/240, 156/241, 156/248, 156/250, 156/257, 156/265, 156/268, 156/277, 156/280, 156/291, 156/295, 156/69, 432/113, 432/114, 432/116, 432/118, 432/128, 174/50.51, 174/52.3, 257/81, 257/87, 257/433, 257/434, 257/264, 250/208.1, 250/214.R, 250/239
• US Class Current: 156/250
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/4835 Heat curing adhesives
• CPC Class Codes: B29C 65/4855 characterised by their physical properties, e.g. being electrically-conductive
• CPC Class Codes: B29C 65/4865 containing additives C09J11/00 and subgroups take precedence
• CPC Class Codes: B29C 65/489 being metals
• CPC Class Codes: B29C 65/50 using adhesive tape , e.g. thermoplastic tape; using threads or the like B29C65/3444 takes precedence
• CPC Class Codes: B29C 65/5007 characterised by the structure of said adhesive tape, threads or the like
• CPC Class Codes: B29C 65/526 by printing or by transfer from the surfaces of elements carrying the adhesive, e.g. using brushes, pads, rollers, stencils or silk screens
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/114 Single butt joints
• CPC Class Codes: B29C 66/1222 comprising at least a lapped joint-segment
• CPC Class Codes: B29C 66/1224 comprising at least a butt joint-segment
• CPC Class Codes: B29C 66/53461 joining substantially flat covers and/or substantially flat bottoms to open ends of container bodies
• CPC Class Codes: B29C 66/61 Joining from or joining on the inside for making tubes by bending sheets and joining from the inside B29C53/387
• 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: B29C 66/72321 consisting of metals or their alloys
• CPC Class Codes: B29C 66/72325 Ceramics
• CPC Class Codes: B29C 66/7392 characterised by the material of at least one of the parts being a thermoplastic
• CPC Class Codes: B29C 66/7394 characterised by the material of at least one of the parts being a thermoset
• CPC Class Codes: B29K 2025/06 : PS, i.e. polystyrene
• CPC Class Codes: B29K 2033/12 : Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B29K 2069/00 : Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29L 2031/3061 : Number plates
• CPC Class Codes: B29L 2031/3481 : Housings or casings incorporating or embedding electric or electronic elements
• CPC Class Codes: H01L 21/4803 : Insulating or insulated parts, e.g. mountings, containers, diamond heatsinks H01L21/4846 takes precedence; printed circuit boards H05K1/00
• CPC Class Codes: H01L 21/4807 : Ceramic parts
• CPC Class Codes: H01L 21/50 : Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
• CPC Class Codes: H01L 2223/54426 : for alignment
• CPC Class Codes: H01L 2223/5446 : Located in scribe lines
• CPC Class Codes: H01L 2224/48091 : Arched
• CPC Class Codes: H01L 2224/48227 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/85 : using a wire connector
• CPC Class Codes: H01L 2224/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 23/057 : the leads being parallel to the base
• CPC Class Codes: H01L 23/10 : characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 23/544 : Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps test patterns for characterising or monitoring manufacturing processes H01L22/00
• CPC Class Codes: H01L 24/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/01072 : Hafnium [Hf]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/16195 : Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/16315 : Shape
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19042 : being an inductor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: Y10T 156/1052 : with cutting, punching, tearing or severing
• CPC Class Codes: Y10T 156/1064 : Partial cutting [e.g., grooving or incising]

Abstract

An optical device is enclosed within a package or module having an optically transmissive or transparent cover that is sealed with an adhesive preform that has been pre-applied onto the bonding areas of the cover. The adhesive preforms are formed of a wet adhesive deposited on a sheet of optically transmissive or transparent material as a preform in predetermined locations and are B-staged or dried to form dry solid adhesive preforms. The preforms may be continuous or have one or more small gaps therein. The sheet of optical material is diced or singulated to produce individual optical covers having an adhesive preform thereon.

Claims

1. A method for making optical covers having an adhesive preform thereon comprising:

providing an optical substrate;

depositing a pattern of adhesive including a plurality of cover bonding patterns on the optical substrate; and

singulating the optical substrate into a plurality of optical covers each of which has one of the cover bonding patterns of adhesive attached thereto.

2. The method of claim 1 wherein the optical substrate includes a sheet of an optically transmissive material.

3. The method of claim 1 wherein depositing a pattern of adhesive includes depositing an adhesive selected from the group consisting of thermoplastic adhesive, thermosetting adhesive, a blend thereof and a mixture thereof.

4. The method of claim 1 wherein depositing a pattern of adhesive includes depositing an adhesive by a method selected from the group consisting of mesh screening, stencil screening, contact screening, mask screening, ink-jet printing, and controlled dispensing.

5. The method of claim 1 further comprising drying or B-staging the deposited pattern of adhesive.

6. The method of claim 1 further comprising drying or B-staging the deposited pattern of adhesive prior to said singulating the optical substrate.

7. The method of claim 1 wherein said depositing a pattern of adhesive includes depositing cover bonding patterns of adhesive each having at least one gap therein, wherein the gap is sized to be filled by the adhesive when the adhesive flows.

8. The method of claim 1 wherein said singulating the optical substrate includes cutting through the optical substrate with a saw producing a kerf.

9. The method of claim 8 wherein adjacent ones of the cover bonding patterns are separated by a distance at least as large as the kerf.

10. The method of claim 8 further comprising cutting partially through the optical substrate with a chamfer-forming saw prior to said cutting through the optical substrate.

11. The method of claim 1 further comprising placing at least one of the optical covers having the bonding pattern of adhesive attached thereto on a substrate to bond the one of the optical covers to the substrate.

12. The method of claim 11 wherein said placing one of the optical covers includes applying sufficient pressure to cause the adhesive to flow.

13. The method of claim 11 wherein the adhesive is a thermosetting adhesive having a tacking temperature and a curing temperature, further including heating the substrate to at least the tacking temperature to tack the thermosetting adhesive thereto, wherein the one of the optical covers is at a temperature less than the tacking temperature until placed on the substrate.

14. The method of claim 13 further including thereafter curing the thermosetting adhesive at the curing temperature.

15. The method of claim 11 wherein the adhesive is a thermoplastic adhesive having a melt-flow temperature, further including heating the one of the optical covers to at least the melt-flow temperature of the thermoplastic adhesive, wherein the substrate is at a temperature lower than the melt-flow temperature when the one of the optical covers is placed thereon.

16. The method of claim 11 wherein said placing one of the optical covers includes employing pick-and-place apparatus to place one of the plurality of optical covers on the substrate.

17. The method of claim 11 wherein the substrate includes a solder having a melting temperature, and wherein the adhesive has a bond strength that substantially decreases at a temperature less than the melting temperature of the solder.

33. The method of claim 7 wherein the at least one gap is shaped to be of nonuniform width.

18. A method for making an optical cover having an adhesive preform thereon comprising:

providing sheet of an optical substrate material that is one of optically transmissive and optically transparent;

depositing a pattern of adhesive including a plurality of cover bonding patterns on the sheet of optical substrate material;

drying or B-staging the deposited pattern of adhesive; and

singulating from the sheet of optical substrate material at least one optical cover which has one of the cover bonding patterns of adhesive attached thereto.

19. The method of claim 18 wherein depositing a pattern of adhesive includes depositing an adhesive selected from the group consisting of thermoplastic adhesive, thermosetting adhesive, a blend thereof and a mixture thereof.

20. The method of claim 18 wherein depositing a pattern of adhesive includes depositing an adhesive by a method selected from the group consisting of mesh screening, stencil screening, contact screening, mask screening, ink-jet printing, and controlled dispensing.

21. The method of claim 18 wherein said drying or B-staging the deposited pattern of adhesive is prior to said singulating from the sheet of optical substrate.

22. The method of claim 18 wherein said depositing a pattern of adhesive includes depositing cover bonding patterns of adhesive each having at least one gap therein, wherein the gap is sized to be filled by the adhesive when the adhesive flows.

23. The method of claim 18 wherein said singulating from the sheet of optical substrate material includes cutting through the sheet of optical substrate material with a saw producing a kerf.

24. The method of claim 23 wherein adjacent ones of the cover bonding patterns are separated by a distance at least as large as the kerf.

25. The method of claim 23 further comprising cutting partially through the sheet of optical substrate material with a chamfer-forming saw prior to said cutting through the sheet of optical substrate material.

26. The method of claim 18 further comprising placing the optical cover having the bonding pattern of adhesive attached thereto on a substrate to bond the optical cover to the substrate.

27. The method of claim 26 wherein said placing the optical cover includes applying sufficient pressure to cause the adhesive to flow.

28. The method of claim 26 wherein the adhesive is a thermosetting adhesive having a tacking temperature and a curing temperature, further including heating the substrate to at least the tacking temperature to tack the thermosetting adhesive thereto, wherein the optical cover is at a temperature less than the tacking temperature until placed on the substrate.

29. The method of claim 28 further including thereafter curing the thermosetting adhesive at the curing temperature.

30. The method of claim 26 wherein the adhesive is a thermoplastic adhesive having a melt-flow temperature, further including heating the optical cover to at least the melt-flow temperature of the thermoplastic adhesive, wherein the substrate is at a temperature lower than the melt-flow temperature when the optical cover is placed thereon.

31. The method of claim 26 wherein said placing the optical cover includes employing pick-and-place apparatus to place the optical cover on the substrate.

32. The method of claim 26 wherein the substrate includes a solder having a melting temperature, and wherein the adhesive has a bond strength that substantially decreases at a temperature less than the melting temperature of the solder.

34. The method of claim 22 wherein the at least one gap is shaped to be of nonuniform width.