Laminate, and element comprising substrate manufactured using same

Patent metadata

Field	Value
Publication number	US-9611358-B2
Application number	US-201414422449-A
Country	US
Kind code	B2
Filing date	Apr 8, 2014
Priority date	Apr 9, 2013
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

The present invention relates to a laminate and a device fabricated using the laminate. The laminate includes a debonding layer including a polyimide resin having a similarity score not greater than 0.5, as calculated by Equation 1 defined in the detailed description, between a carrier substrate and a flexible substrate. According to the present invention, the flexible substrate can be easily separated from the carrier substrate without the need for further processing such as laser or light irradiation. Therefore, the use of the laminate facilitates the fabrication of the device having the flexible substrate. The device may be, for example, a flexible display device. In addition, the device can be prevented from deterioration of reliability and occurrence of defects caused by laser or light irradiation. This ensures improved characteristics and high reliability of the device.

First claim

The invention claimed is:

1. A laminate comprising:
a carrier substrate;
a debonding layer disposed on at least one surface of the carrier substrate and comprising a polyimide resin; and
a flexible substrate disposed on the debonding layer,
wherein the polyimide resin has a similarity score not greater than 0.5, as calculated by Equation 1:
Similarity score=α FIT ( k 1 ×Ls dianhydride,i +k 2 ×Ls diamine,j ) k 0   [Equation 1]

where
Ls dianhydride,i =Exp[−k 3 ×Coeff i ]×V i y 0
Ls diamine,j =Exp[−k 4 ×Coeff j ]×V j y 0
k 0 =2.00,
y 0 =−1.00,
k 1 =206.67,
k 2 =124.78,
k 3 =3.20,
k 4 =5.90,
Coeff i and Coeff j are molecular asphericities calculated from the structures of dianhydride i and diamine j as monomers of the polyimide, respectively, using version 2.2.4 of algorithms for the encoding of molecular structures by Molecular Networks GmbH,
V i and V j are McGowan volumes calculated from the structures of dianhydride i and diamine j as the monomers, respectively, using version 2.2.4 of algorithms for the encoding of molecular structures by Molecular Networks GmbH, and
α FIT is 1.0 if exp(−4.0×|Coeff i −Coeff j |)+0.08<0.90 and is a constant from 0.1 to 0.95 if exp(−4.0×|Coeff i −Coeff j |)+0.08≧0.90,
wherein the diamine is represented by Formula 4b:

wherein R 22 and R 23 are each independently a C 1 -C 10 alkyl or C 1 -C 10 haloalkyl group, m and n are each independently an integer from 0 to 4, and p is an integer of 0.

2. The laminate according to claim 1 , having an adhesive strength ratio from 0.001 to 0.5, wherein said adhesive strength ratio is measured as A2/A1, wherein A2 is adhesive strength of the debonding layer to the flexible substrate after applying physical stimulus causing no chemical changes in the debonding layer; and A1 is adhesive strength of the debonding layer to the flexible substrate before applying physical stimulus.

3. The laminate according to claim 1 , wherein the debonding layer has a peel strength not greater than 0.3 N/cm from the flexible substrate.

4. The laminate according to claim 1 , wherein the debonding layer has an adhesive strength of at least 1 N/cm to the flexible substrate.

5. The laminate according to claim 1 , wherein cross-sections of the flexible substrate are exposed.

6. The laminate according to claim 1 , wherein the polyimide resin has an imidization degree of 60% to 99% when the imidization degree is defined as the percentage of the integrated intensity of the CN bands observed at 1350 to 1400 cm −1 in the IR spectrum after a composition comprising a polyamic acid resin is applied and imidized at a temperature of 200° C. or above with respect to the integrated intensity (100%) of the CN bands observed in the same wavelength range after the composition is imidized at a temperature of 500° C. or above.

7. The laminate according to claim 1 , wherein the polyimide resin has a glass transition temperature of 200° C. or above.

8. The laminate according to claim 1 , wherein the polyimide resin is prepared by reacting a tetracarboxylic dianhydride of Formula 1:

wherein A is a tetravalent aromatic organic group of Formula 2a or 2b:

wherein R 11 is a C 1 -C 4 alkyl or C 1 -C 4 haloalkyl group, a is an integer from 0 to 3, and b is an integer from 0 to 2,

wherein R 12 to R 14 are each independently a C 1 -C 4 alkyl or C 1 -C 4 haloalkyl group, c and e are each independently an integer from 0 to 3, d is an integer from 0 to 4, and f is an integer from 0 to 3, with an aromatic diamine compound having a linear structure to prepare a polyamic acid, and curing the polyamic acid at a temperature of 200° C. or above.

9. The laminate according to claim 1 , wherein the debonding layer has a coefficient of thermal expansion not higher than 30 ppm/° C. at a temperature of 100 to 200° C. and a 1% thermal decomposition temperature (Td1%) of 450° C. or above.

10. The laminate according to claim 1 , wherein the carrier substrate is a glass substrate or a metal substrate.

11. The laminate according to claim 1 , wherein the flexible substrate has a structure selected from the group consisting of a thin film glass layer, a polymer layer, and a multilayer laminate thereof.

12. The laminate according to claim 11 , wherein the polymer layer comprises at least one polymer resin selected from the group consisting of polyethersulfone, polyethylene naphthalate, polyethylene terephthalate, polycarbonate, polyimide, polyether imide, polyamide imide, polyester, polyether amide imide, polyester amide imide, and polyarylate.

13. The laminate according to claim 11 , wherein the polymer layer comprises a polyimide resin having an imidization degree of 50 to 99% and a glass transition temperature of 200° C. or above.

14. A method for producing a laminate, comprising:
forming a debonding layer comprising a polyimide resin on at least one surface of a carrier substrate; and
forming a flexible substrate on the debonding layer,
wherein the polyimide resin has a similarity score not greater than 0.5, as calculated by Equation 1:
Similarity score=α FIT ( k 1 ×Ls dianhydride,i +k 2 ×Ls diamine,j ) k 0   [Equation 1]

where
Ls dianhydride,i =Exp[−k 3 ×Coeff i ]×V i y 0
Ls diamine,j =Exp[−k 4 ×Coeff j ]×V j y 0
k 0 =2.00,
y 0 =−1.00,
k 1 =206.67,
k 2 =124.78,
k 3 =3.20,
k 4 =5.90,
Coeff i and Coeff j are molecular asphericities calculated from the structures of dianhydride i and diamine j as monomers of the polyimide, respectively, using version 2.2.4 of algorithms for the encoding of molecular structures by Molecular Networks GmbH,
V i and V j are McGowan volumes calculated from the structures of dianhydride i and diamine j as the monomers, respectively, using version 2.2.4 of algorithms for the encoding of molecular structures by Molecular Networks GmbH, and
α FIT is 1.0 if exp(−4.0×|Coeff i −Coeff j |)+0.08<0.90 and is a constant from 0.1 to 0.95 if exp(−4.0×|Coeff i −Coeff j |)+0.08≧0.90,
wherein the diamine is represented by Formula 4b:

wherein R 22 and R 23 are each independently a C 1 -C 10 alkyl or C 1 -C 10 haloalkyl group, m and n are each independently an integer from 0 to 4, and p is an integer of 0.

15. The method according to claim 14 , wherein the flexible substrate is formed by a method selected from the group consisting of a method comprising disposing a glass thin film layer on the debonding layer and heat treating the glass thin film layer at a temperature of 20 to 300° C., a method comprising applying a composition comprising a polymer or a precursor thereof and curing the composition, and a combination thereof.

16. The method according to claim 14 , further comprising heat treating the debonding layer at a temperature of 300° C. or above for 1 to 30 minutes after the step of forming the debonding layer.

17. A method for producing a device substrate, comprising:
producing a laminate comprising a carrier substrate, a debonding layer, and a flexible substrate by the metho

Assignees

• Lg Chemical Ltd

Inventors

• Jeong Hye Won
• Kim Kyungjun
• Kim Kyoung Hoon
• Park Chan Hyo
• Shin Bora
• Lee Seung Yup
• Park Hangah
• Lee Jinho
• Im Mira

Classifications

• H10P72/7412

  the auxiliary support including means facilitating the separation of a device or wafer from the auxiliary support · CPC title

• B32B2457/20

  Displays, e.g. liquid crystal displays, plasma displays · CPC title

• B32B27/08

  of synthetic resin · CPC title

• B32B2379/08

  Polyimides · CPC title

• Y10S156/93

  Semiconductive product delaminating, e.g. delaminating emiconductive wafer from underlayer · CPC title