Apparatus and method for creating crack initiation sites in a self-fracturing frangible member

Patent metadata

Field	Value
Publication number	US-11459266-B2
Application number	US-202016903067-A
Country	US
Kind code	B2
Filing date	Jun 16, 2020
Priority date	May 16, 2018
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

An apparatus comprises a stressed glass member and an actuator mounted on the stressed glass member. A power source is coupled to the actuator. An abrasion structure is disposed between the actuator and the stressed glass member. The abrasion structure comprises abrading features in contact with the stressed glass member. The abrading features have a hardness higher than a hardness of the stressed glass member. When energized by the power source, the actuator is configured to induce movement of the abrasion structure that causes the abrading features to create scratches in the stressed glass member to a depth sufficient to initiate fracture of the stressed glass member.

First claim

The invention claimed is:

1. A fracturable apparatus, comprising:
a stressed glass member; and
a powered actuator permanently attached to the stressed glass member, the actuator comprising or coupled to an abrasion structure in contact with the stressed glass member;
wherein the actuator is configured to induce movement of the abrasion structure in-plane with respect to the stressed glass member that causes the abrasion structure to create scratches in the stressed glass member, the scratches or cracks formed at the scratches having a depth sufficient to initiate fracture of the stressed glass member.

2. The apparatus of claim 1 , comprising trigger circuitry coupled to a power source, the trigger circuitry configured to cause the power source to energize the actuator in response to a trigger stimulus.

3. The apparatus of claim 1 , wherein the actuator is configured to apply a force to the abrasion structure out-of-plane with respect to the stressed glass member.

4. The apparatus of claim 1 , wherein the abrasion structure comprise a plurality of abrading features in contact with the stressed glass member and having a hardness higher than a hardness of the stressed glass member.

5. The apparatus of claim 1 , wherein the actuator comprises piezoelectric material, a motor, a solenoid or an electrostatic actuator.

6. The apparatus of claim 1 , wherein the actuator comprises:
a first piezoelectric stage configured to cause movement of the abrasion structure in-plane with respect to the stressed glass member; and
a second piezoelectric stage configured to cause movement of the abrasion structure out-of-plane with respect to the surface of the stressed glass member.

7. The apparatus of claim 1 , wherein:
the abrasion structure comprises an adhesive and abrading features interspersed within the adhesive at least along a surface of the abrasion structure that contacts the stressed glass member; and
the abrading features comprise one or more of diamond, boron carbide, silicon carbide, cubic boron nitride, alumina, and zirconia.

8. The apparatus of claim 1 , comprising a clamp or a spring coupled to the actuator and the stressed glass member, the clamp or spring configured to apply a force to the actuator and the abrasion structure in a direction out-of-plane with respect to the stressed glass member.

9. A fracturable apparatus, comprising:
a stressed glass substrate;
one or more electronic devices having at least one transistor disposed on the stressed glass substrate; and
a powered actuator permanently attached to the stressed glass substrate, the actuator comprising or coupled to an abrasion structure in contact with the stressed glass substrate;
wherein the actuator is configured to induce movement of the abrasion structure in-plane with respect to the stressed glass substrate that causes the abrasion structure to create scratches in the stressed glass substrate, the scratches or cracks formed at the scratches having a depth sufficient to initiate fracture of the stressed glass substrate such that fracture of the stressed glass substrate fractures the one or more electronic devices.

10. The apparatus of claim 9 , comprising a clamp or a spring coupled to the actuator and the stressed glass substrate, the clamp or spring configured to apply a force to the actuator and the abrasion structure in a direction out-of-plane with respect to the stressed glass substrate.

11. The apparatus of claim 9 , comprising trigger circuitry coupled to a power source, the trigger circuitry configured to cause the power source to energize the actuator in response to a trigger stimulus.

12. The apparatus of claim 9 , wherein the actuator is configured to apply a force to the abrasion structure out-of-plane with respect to the stressed glass substrate.

13. The apparatus of claim 9 , wherein the abrasion structure comprise a plurality of abrading features in contact with the stressed glass substrate and having a hardness higher than a hardness of the stressed glass substrate.

14. The apparatus of claim 9 , wherein the actuator comprises piezoelectric material, a motor, a solenoid or an electrostatic actuator.

15. The apparatus of claim 9 , wherein the actuator comprises:
a first piezoelectric stage configured to cause movement of the abrasion structure in-plane with respect to the stressed glass substrate; and
a second piezoelectric stage configured to cause movement of the abrasion structure out-of-plane with respect to the surface of the stressed glass substrate.

16. The apparatus of claim 9 , wherein:
the abrasion structure comprises an adhesive and abrading features interspersed within the adhesive at least along a surface of the abrasion structure that contacts the stressed glass substrate; and
the abrading features comprise one or more of diamond, boron carbide, silicon carbide, cubic boron nitride, alumina, and zirconia.

17. A method implemented by a fracturable apparatus, comprising:
energizing a powered actuator permanently attached to a stressed glass member;
inducing movement of an abrasion structure in contact with the stressed glass member using the actuator; and
creating scratches in the stressed glass member using the abrasion structure, the scratches or cracks formed at the scratches having a depth sufficient to initiate fracture of the stressed glass member, wherein:
inducing movement of the abrasion structure comprises inducing movement of the abrasion structure in-plane with respect to the stressed glass member; and
the in-plane movement of the abrasion structure causes the abrasion structure to create the scratches in the stressed glass member.

18. The method of claim 17 , wherein:
the stressed glass member comprises a stressed glass substrate;
one or more electronic devices having at least one transistor are disposed on the stressed glass substrate; and
initiating fracture of the stressed glass substrate causes fracture of the one or more electronic devices.

19. The method of claim 17 , comprising:
generating a trigger signal at the fracturable apparatus in response to a remotely generated trigger stimulus; and
energizing the actuator in response to the trigger signal.

20. The method of claim 17 , wherein:
the abrasion structure comprise a plurality of abrading features in contact with the stressed glass member and having a hardness higher than a hardness of the stressed glass member; and
creating scratches in the stressed glass member comprises creating scratches in the stressed glass member using the plurality of abrading features.

21. The method of claim 17 , comprising applying a force to the abrasion structure out-of-plane with respect to the stressed glass member.

Assignees

• Palo Alto Res Ct Inc

Inventors

• Murphy Kathryn
• Limb Scott J
• Johnson David Mathew

Classifications

• H10W42/40

  protecting against tampering, e.g. unauthorised inspection or reverse engineering · CPC title

• C03B33/105 Primary

  Details of cutting or scoring means, e.g. tips · CPC title

• B06B1/0607

  using multiple elements (B06B1/064 and B06B1/0688 take precedence) · CPC title

• B24B1/04 Primary

  subjecting the grinding or polishing tools, the abrading or polishing medium or work to vibration, e.g. grinding with ultrasonic frequency (involving oscillating or vibrating containers B24B31/06; superfinishing surfaces on work, e.g. by means of abrading blocks reciprocating with high frequency, B24B35/00) · CPC title

• H01L23/57

  Electricity · mapped topic