Foldable electronic device modules with impact and bend resistance

1. A foldable electronic device module, comprising:

a cover element having a thickness from 25 μm to 200 μm and a cover element elastic modulus from 20 GPa to 140 GPa, the cover element further comprising a component having a glass composition, a first primary surface, and a second primary surface;

a stack comprising:

(a) an interlayer having first and second primary surfaces, an interlayer elastic modulus from 0.01 GPa to 10 GPa and a thickness from 50 μm to 200 μm, and

(b) a flexible electronic device substrate having a thickness from 25 μm to 200 μm that is coupled to the interlayer; and

a first adhesive joining the stack to the second primary surface of the cover element, the first adhesive characterized by an elastic modulus from 0.001 GPa to 10 GPa and a thickness from 5 μm to about 25 μm,

wherein the foldable electronic device module comprises an impact resistance characterized by a tensile stress of less than 4100 MPa at the first primary surface of the cover element and a tensile stress of less than 8300 MPa at the second primary surface of the cover element upon impact of a ball point pen dropped from a pen drop height of 10 cm with the cover element in a Pen Drop Test.

2. The foldable electronic device module according to claim 1 , wherein the impact resistance is characterized by the tensile stress of less than 3900 MPa at the first primary surface of the cover element and the tensile stress of less than 7000 MPa at the second primary surface of the cover element upon impact of the ball point pen dropped from the pen drop height of 10 cm with the cover element in the Pen Drop Test.

3. The foldable electronic device module according to claim 2 , wherein the impact resistance is characterized by the tensile stress of less than 3700 MPa at the first primary surface of the cover element and the tensile stress of less than 5500 MPa at the second primary surface of the cover element upon impact of the ball point pen dropped from the pen drop height of 10 cm with the cover element in the Pen Drop Test.

4. The foldable electronic device module according to claim 1 , wherein the interlayer elastic modulus is from 5 GPa to 10 GPa.

5. The foldable electronic device module according to claim 1 , wherein the thickness of the interlayer is from 125 μm to 200 μm.

6. The foldable electronic device module according to claim 5 , wherein the impact resistance is characterized by the tensile stress of less than 3650 MPa at the first primary surface of the cover element and the tensile stress of less than 6000 MPa at the second primary surface of the cover element upon impact of the ball point pen dropped from the pen drop height of 10 cm with the cover element in the Pen Drop Test.

7. The foldable electronic device module according to claim 1 , wherein the flexible electronic device substrate is a flexible organic light emitting diode (OLED) substrate,

wherein the first adhesive comprises one or more of an epoxy, a urethane, an acrylate, an acrylic, a styrene copolymer, a polyisobutylene, a polyvinyl butyral, an ethylene vinyl acetate, sodium silicate, an optically clear adhesive (OCA), a pressure sensitive adhesive (PSA), polymeric foam, a natural resin, and a synthetic resin, and

further wherein the interlayer comprises one or more of a poly(methyl methacrylate), a polycarbonate, a polyethylene terephthalate, a polyimide, a cellulose acetate butyrate, a polystyrene, a styrene acrylonitrile, a styrene methyl methacrylate, a glass fiber reinforced polymer (GFRP), silica particles, zirconia particles, titania particles, and silica sol-gels.

8. A foldable electronic device module, comprising:

a cover element having a thickness from 25 μm to 200 μm and a cover element elastic modulus from 20 GPa to 140 GPa, the cover element further comprising a component having a glass composition, a first primary surface, and a second primary surface;

a stack comprising:

(a) an interlayer having first and second primary surfaces, an interlayer elastic modulus from 0.01 GPa to 10 GPa and a thickness from 50 μm to 200 μm, and

(b) a flexible electronic device substrate having a thickness from 25 μm to 200 μm that is coupled to the interlayer; and

a first adhesive joining the stack to the second primary surface of the cover element, the first adhesive characterized by an elastic modulus from 0.001 GPa to 10 GPa and a thickness from 5 μm to 25 μm,

wherein the foldable electronic device module comprises a bending resistance characterized by a bend force of less than 110 N in the foldable electronic device module upon bending the foldable electronic device module in a Two-Point Bend Test such that the first primary surface of the cover element is concave.

9. The foldable electronic device module according to claim 8 , wherein the bend force is less than 70 N in the foldable electronic device module upon bending the foldable electronic device module in the Two-Point Bend Test such that the first primary surface of the cover element is concave.

10. The foldable electronic device module according to claim 8 , wherein the thickness of the interlayer is from 50 μm to 125 μm.

11. The foldable electronic device module according to claim 10 , wherein the bend force is less than 60 N in the foldable electronic device module upon bending the foldable electronic device module in the Two-Point Bend Test such that the first primary surface of the cover element is concave.

12. The foldable electronic device module according to claim 8 , wherein the interlayer elastic modulus is from 0.01 GPa to 5 GPa.

13. The foldable electronic device module according to claim 12 , wherein the bend force is less than 70 N in the foldable electronic device module upon bending the foldable electronic device module in the Two-Point Bend Test such that the first primary surface of the cover element is concave.

14. The foldable electronic device module according to claim 8 , wherein the flexible electronic device substrate is a flexible organic light emitting diode (OLED) substrate,

wherein the first adhesive comprises one or more of an epoxy, a urethane, an acrylate, an acrylic, a styrene copolymer, a polyisobutylene, a polyvinyl butyral, an ethylene vinyl acetate, sodium silicate, an optically clear adhesive (OCA), a pressure sensitive adhesive (PSA), polymeric foam, a natural resin, and a synthetic resin, and

further wherein the interlayer comprises one or more of a poly(methyl methacrylate), a polycarbonate, a polyethylene terephthalate, a polyimide, a cellulose acetate butyrate, a polystyrene, a styrene acrylonitrile, a styrene methyl methacrylate, a glass fiber reinforced polymer (GFRP), silica particles, zirconia particles, titania particles, and silica sol-gels.

15. A foldable electronic device module, comprising:

a cover element having a thickness from 25 μm to 200 μm and a cover element elastic modulus from 20 GPa to 140 GPa, the cover element further comprising a component having a glass composition, a first primary surface, and a second primary surface;

a stack comprising:

(a) an interlayer having first and second primary surfaces, an interlayer elastic modulus from 0.01 GPa to 10 GPa and a thickness from 50 μm to 200 μm, and

(b) a flexible electronic device substrate having a thickness from 25 μm to 200 μm that is coupled to the interlayer; and

a first adhesive joining the stack to the second primary surface of the cover element, the first adhesive characterized by an elastic modulus from 0.001 GPa to 10 GPa and a thickness from 5 μm to 25 μm,

wherein the foldable electronic device module comprises a bend stress resistance characterized by a tensile stress of less than 200 MPa at the second primary surface of the cover element upon bending the foldable electronic device module in a Two-Point Bend Test with a plate spacing of 6 mm such that the first primary surface of the cover element is concave.

16. The foldable electronic device module according to claim 15 , wherein the bend stress resistance is characterized by the tensile stress of less than 150 MPa at the second primary surface of the cover element upon bending the foldable electronic device module in the Two-Point Bend Test with the plate spacing of 6 mm such that the first primary surface of the cover element is concave.

17. The foldable electronic device module according to claim 15 , wherein the interlayer elastic modulus is from 0.01 GPa to 5 GPa.

18. The foldable electronic device module according to claim 17 , wherein the bend stress resistance is characterized by the tensile stress of less than 140 MPa at the second primary surface of the cover element upon bending the foldable electronic device module in the Two-Point Bend Test with the plate spacing of 6 mm such that the first primary surface of the cover element is concave.

19. The foldable electronic device module according to claim 15 , wherein the thickness of the interlayer is from 50 μm to 125 μm.

20. The foldable electronic device module according to claim 19 , wherein the bend stress resistance is characterized by the tensile stress of less than 80 MPa at the second primary surface of the cover element upon bending the foldable electronic device module in the Two-Point Bend Test with the plate spacing of 6 mm such that the first primary surface of the cover element is concave.

21. The foldable electronic device module according to claim 15 , wherein the flexible electronic device substrate is a flexible organic light emitting diode (OLED) substrate,

wherein the first adhesive comprises one or more of an epoxy, a urethane, an acrylate, an acrylic, a styrene copolymer, a polyisobutylene, a polyvinyl butyral, an ethylene vinyl acetate, sodium silicate, an optically clear adhesive (OCA), a pressure sensitive adhesive (PSA), polymeric foam, a natural resin, and a synthetic resin, and

further wherein the interlayer comprises one or more of a poly(methyl methacrylate), a polycarbonate, a polyethylene terephthalate, a polyimide, a cellulose acetate butyrate, a polystyrene, a styrene acrylonitrile, a styrene methyl methacrylate, a glass fiber reinforced polymer (GFRP), silica particles, zirconia particles, titania particles, and silica sol-gels.

22. A foldable electronic device module, comprising:

a cover element having a thickness from 25 μm to 200 μm and a cover element elastic modulus from 20 GPa to 140 GPa, the cover element further comprising a component having a glass composition, a first primary surface, and a second primary surface;

a stack comprising:

(a) an interlayer having first and second primary surfaces, an interlayer elastic modulus from 0.01 GPa to 140 GPa and a thickness from 50 μm to 200 μm, and

(b) a flexible electronic device substrate having a thickness from 25 μm to 200 μm that is coupled to the interlayer; and

a first adhesive joining the stack to the second primary surface of the cover element, the first adhesive characterized by an elastic modulus from 1 GPa to 10 GPa and a thickness from 5 μm to 25 μm,

wherein the foldable electronic device module comprises an impact resistance characterized by an average pen drop height of 6 cm or greater for a set of impacts to the cover element in a Pen Drop Test.

23. The foldable electronic device module according to claim 22 , wherein the average pen drop height is 7.2 cm or greater for the set of impacts to the cover element in the Pen Drop Test.

24. The foldable electronic device module according to claim 22 , wherein the thickness of the interlayer is of about 5 μm and comprises a UV-cured photopolymer.