El element having a color filter formed on an upper electrode

• US 5,958,610 A
• Filed: 02/20/1997
• Issued: 09/28/1999
• Est. Priority Date: 02/22/1996
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Tamura, Hironobu, Hattori, Tadashi, Hattori, Yutaka, Ito, Nobuei, Yonekawa, Tomohiro
• Primary Examiner(s): YAMNITZKY, MARIE ROSE
• Application Number:
  US08/802,911
• Time in Patent Office: 950 Days
• Field of Search: 428/332, 428/336, 428/690, 428/917, 313/500, 313/506, 313/507, 313/509, 257/88, 257/89, 257/90, 257/91, 257/98, 430/7, 430/27, 430/319, 430/349, 430/350, 427/66, 156/275.5
• US Class Current: 428/690
• CPC Class Codes: H05B 33/10 Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
• CPC Class Codes: H05B 33/22 characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers
• CPC Class Codes: Y10S 428/917 Electroluminescent
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

An EL element having a color filter formed on an upper electrode thereof enables a decrease in the pixel loss or line defects. In the EL element, a lower transparent electrode, first insulating layer, luminescent layer and upper transparent electrode are laminated on a glass substrate. Further, a color filter is formed on the upper transparent electrode. As the color filter there is used a posi-resist having an average molecular weight in a range of from 100 to 50000 or a nega-resist having a polymerization reaction percentage in a range of from 5% to 70%.

Claims

1. An EL element comprising an insulating substrate and a lower electrode, insulating layer, luminescent layer and upper transparent electrode laminated directly or indirectly on said insulating substrate, said EL element further comprising a color filter made of organic material and formed on and directly contacting said upper transparent electrode, said organic material having an average molecular weight in a range of from 100 to 50000.

2. An EL element as set forth in claim 1, wherein said average molecular weight of said organic material is equal to or less than 10000.

3. An EL element as set forth in claim 1, wherein said organic material becomes alkali-soluble by radiation of light thereonto so that light-radiated portions are etchable with an alkaline etchant to pattern said color filter.

4. An EL element as set forth in claim 1, wherein said color filter has a thickness of 2 μ

m or less.

5. An EL element as set forth in claim 1, wherein said color filter has a thickness that ran between 0.1 μ

m and 2 μ

m inclusive.

6. A method of manufacturing an EL element, comprising steps of:

preparing an insulating substrate;

laminating a lower electrode, insulating layer, luminescent layer and upper transparent electrode directly or indirectly on said insulating substrate; and

forming on, and directly contacting said upper transparent electrode, a color filter which is made of organic material,

wherein the step of forming said color filter includes a step of heating said color filter to cause said organic material to have an average molecular weight within a range of from 100 to 50000.

7. A method of manufacturing an EL element as set forth in claim 6, wherein said heating step heats said color filter at a heating temperature in a range of from 20°

C. to 180°

C.

8. A method of manufacturing an EL element as set forth in claim 6, wherein said organic material has a property of becoming alkali-soluble by radiation of light thereonto.

9. A method of manufacturing an EL element as set forth in claim 6, wherein said color filter has a thickness of 2 μ

m or less.

10. A method of manufacturing an EL element as set forth in claim 6, wherein said color filter has a thickness that ranges between 0.1 μ

m and 2 μ

m inclusive.

11. A method of manufacturing an EL panel, comprising steps of

preparing an insulating substrate;

laminating a lower electrode, insulating layer, luminescent layer and upper transparent electrode directly or indirectly on said insulating substrate;

forming on, and directly contacting said upper transparent electrode, a color filter which is made of organic material to form an EL element, the step of forming said color filter including a step of heating said color filter to cause said organic material to have an average molecular weight within a range of from 100 to 50000; and

bonding said EL element and an opposing substrate to each other with bonding agent, said bonding agent being hardened by being subject to a thermo-setting temperature which is set to be at a temperature that is equal to or lower than a heating temperature of said step of heating said color filter.

12. An EL element comprising:

an insulating substrate;

a lower electrode formed on said insulating substrate;

a first insulating layer formed on said lower electrode;

a luminescent layer formed on said first insulating layer;

a second insulating layer formed on said luminescent layer;

an upper electrode formed on said second insulating layer; and

a color filter formed on and directly contacting said upper electrode, said color filter being made of organic material and having an average molecular weight in a range of from 100 to 50000.