Bendable electronic device modules, articles and methods of making the same
A foldable electronic device module includes a glass cover element having a thickness from about 25 μm to about 200 μm, an elastic modulus from about 20 GPa to about 140 GPa and a puncture resistance of at least 1.5 kgf. The module further includes a stack with a thickness between about 100 μm and about 600 μm; and a first adhesive joining the stack to the cover element with a shear modulus between about 1 MPa and about 1 GPa. The stack further includes a panel, an electronic device, and a stack element affixed to the panel with a stack adhesive. Further, the device module is characterized by a tangential stress at a primary surface of the cover element of no greater than about 1000 MPa in tension upon bending the module to a radius from about 20 mm to about 2 mm.
1. A foldable electronic device module, comprising:
a cover element having a thickness from about 25 μm to about 200 μm and a cover element elastic modulus from about 20 GPa to about 140 GPa, the cover element further comprising:
(a) a component having a glass composition,
(b) a first primary surface, and
(c) a second primary surface;
a stack having a thickness from about 100 μm to about 600 μm, the stack further comprising:
(a) a panel having first and second primary surfaces, and a panel elastic modulus between about 300 MPa and about 10 GPa, and
(b) an electronic device coupled to the panel; and
a first adhesive configured to join the stack to the second primary surface of the cover element, the first adhesive characterized by a shear modulus between about 0.1 MPa and about 100 MPa,
wherein the device module is characterized by a tangential stress at the second primary surface of the cover element of no greater than about 1000 MPa in tension upon bending the module in a two-point configuration to a bend radius from about 20 mm to about 2 mm such that the first primary surface is in compression and the bend radius is measured from a center point above the first primary surface of the cover element to the second primary surface of the panel.
2. A foldable electronic device module, comprising:
a cover element having a thickness from about 25 μm to about 200 μm and a cover element elastic modulus from about 20 GPa to about 140 GPa, the cover element further comprising:
(a) a component having a glass composition,
(b) a first primary surface, and
(c) a second primary surface;
a stack having a thickness from about 100 μm to about 600 μm, the stack further comprising:
(a) a panel having first and second primary surfaces, and a panel elastic modulus between about 300 MPa and about 10 GPa,
(b) an electronic device coupled to the panel, and
(c) a stack element having a stack element elastic modulus between about 1 GPa and about 5 GPa, the stack element affixed to the panel with a stack adhesive; and
a first adhesive configured to join the stack element to the second primary surface of the cover element, the first adhesive characterized by a shear modulus between about 1 MPa and about 1 GPa,
wherein the device module is characterized by a tangential stress at the second primary surface of the cover element of no greater than about 1000 MPa in tension upon bending the module in a two-point configuration to a bend radius from about 20 mm to about 2 mm such that the first primary surface is in compression and the bend radius is measured from a center point above the first primary surface of the cover element to the second primary surface of the panel.
3. The module of claim 1 , wherein the tangential stress at the second primary surface of the cover element is no greater than about 800 MPa in tension.
4. The module of claim 1 , wherein the tangential stress at the second primary surface of the cover element is no greater than about 700 MPa in tension.
5. The module of claim 1 , wherein the cover element is further characterized by no cohesive failures upon bending the module, in a two-point configuration, from an un-bent configuration to the bend radius for at least 200,000 bend cycles.
6. The module of claim 1 , wherein the cover element is a glass element having a cover element elastic modulus from about 50 GPa to about 100 GPa.
7. The module of claim 1 , wherein the first adhesive is characterized by a shear modulus between about 1 MPa and about 100 MPa.
8. The module of claim 1 , wherein the first adhesive is characterized by a thickness from about 5 μm to about 60 μm.
9. The module of claim 1 , wherein the first adhesive is characterized by a thickness from about 10 μm to about 36 μm.
10. The module of claim 1 , wherein the first adhesive is characterized by a shear modulus between about 1 MPa and about 100 MPa and a thickness from about 10 μm to about 20 μm.
11. The module of claim 1 , wherein the first adhesive is further characterized by a Poisson's ratio from about 0.1 to about 0.25.
12. The module of claim 1 , wherein the cover element is further characterized by a puncture resistance of at least 1.5 kgf when the first primary surface of the cover element is loaded with a tungsten carbide ball having a diameter of 1.5 mm.
13. The module of claim 2 , wherein the stack adhesive is characterized by a shear modulus between about 10 kPa and about 100 kPa.
14. The module of claim 2 , wherein the stack adhesive is characterized by a thickness from about 5 μm to about 60 μm.
15. The module of claim 2 , wherein the stack adhesive is characterized by a thickness from about 30 μm to about 60 μm.
16. The module of claim 2 , wherein the stack adhesive is characterized by a Poisson's ratio from about 0.4 to about 0.5.
17. The module of claim 2 , wherein the stack element comprises a touch sensor and a polarizer.
18. The module of claim 2 , wherein the stack element comprises a touch sensor, a polarizer, and an internal adhesive configured to attach the touch sensor to the polarizer.
19. The module of claim 1 , wherein the device module is further characterized by a bending force of no more than about 150 N upon bending the module in a two-point configuration to a bend radius from about 20 mm to about 3 mm such that the first primary surface is in compression and the bend radius is measured from a center point above the first primary surface of the cover element to the second primary surface of the panel.
20. The module of claim 1 , wherein the device module is further characterized by a bending force of no more than about 80 N upon bending the module in a two-point configuration to a bend radius from about 20 mm to about 3 mm such that the first primary surface is in compression and the bend radius is measured from a center point above the first primary surface of the cover element to the second primary surface of the panel.