Display devices

• US 4,259,679 A
• Filed: 04/13/1979
• Issued: 03/31/1981
• Est. Priority Date: 01/17/1977
• Status: Expired due to Term

• Current Assignee: Plessey Overseas Limited (Marconi Holdings Company Limited)
• Original Assignee: Plessey Handel und Investments AG
• Inventors: Knibb, Terence F., O'Rourke, Richard G.
• Primary Examiner(s): Edlow, Martin H.
• Application Number:
  US06/029,879
• Time in Patent Office: 718 Days
• Field of Search: 357/17, 357/18, 357/71, 362/19
• US Class Current: 257/98
• CPC Class Codes: G01R 13/404 for discontinuous display, i.e. display of discrete values analogue/digital conversion H03M1/00
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01039 Yttrium [Y]
• CPC Class Codes: H01L 2924/01057 Lanthanum [La]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A display device comprises a light emitting diode chip mounted on a substrate. To reduce or eliminate reflections from metallic connections to the chip, the metallic parts are electroplated with a light absorbing material.

Claims

1. A display device comprising a substrate, a light emitting diode chip, said light emitting diode chip being bonded to said substrate, a plurality of metallic electrical connections, a number of said plurality of electrical connections being bonded to said substrate and a number being connected to said light emitting diode chip, at least some of said metallic electrical connections being electroplated with a layer of light absorbing material.

2. A display device as claimed in claim 1 wherein said number of said plurality of electrical connections bonded to said substrate comprises a plurality of gold connectors.

3. A display device as claimed in claim 2 wherein said light emitting diode chip is bonded to one of said plurality of gold connectors by an electrically conductive adhesive.

4. A display device as claimed in claim 3 in which said electrically conductive adhesive comprises silver loaded epoxy resin.

5. A display device as claimed in claim 1 wherein said number of said plurality of electrical connectors connected to said light emitting chip comprises at least one electrically conductive wire.

6. A display device as claimed in claim 5 wherein said at least one electrically conductive wire is gold.

7. A display device as claimed in claim 5 wherein said at least one electrically conductive wire is aluminium.

8. A display device as claimed in claim 5 wherein said at least one electrically conductive wire is a combination of aluminium and titanium.

9. A display device as claimed in claim 1 wherein said layer of light absorbing material comprises black chromium.

10. A display device as claimed in claim 1 wherein said layer of light absorbing material comprises black platinum.

11. A display device as claimed in claim 1 wherein the device is protected from damage by encapasulating means.

12. A display device as claimed in claim 11 wherein the encapsulating means comprises a transparent plate secured to light absorbing wall members.