Rigid to flexible PC transition

• US 9,549,463 B1
• Filed: 05/14/2015
• Issued: 01/17/2017
• Est. Priority Date: 05/16/2014
• Status: Active Grant

• Current Assignee: Multek Technologies Limited
• Original Assignee: Multek Technologies Limited
• Inventors: Vrtis, Joan K., Glickman, Michael James, Bergman, Mark, Shang, Shurui
• Primary Examiner(s): Sawyer, Steven T
• Application Number:
  US14/712,823
• Time in Patent Office: 614 Days
• US Class Current: 1/1
• CPC Class Codes: H05K 1/0281 Reinforcement details thereof
• CPC Class Codes: H05K 1/0283 Stretchable printed circuits
• CPC Class Codes: H05K 3/24 Reinforcing the conductive pattern by solder coating H05K3/3457

Abstract

A circuit board comprises one or more rigid sections, one or more flexible sections, and one or more transition areas where the circuit board transitions from the rigid section to the flexible section. One or more mechanically restrictive components are applied at a transition area to prevent failure and/or breakage of the circuit as it is bent and flexed. The mechanically restrictive components can be dispersed throughout the circuit as a coverlay, an underlay, and symmetrically positioned within the circuit board as an overlay and an underlay.

Claims

1. A circuit board comprising:

one or more rigid sections including a first thickness;

one or more flexible sections including a second thickness different from the first thickness and coupled to the one or more rigid sections;

one or more transition areas forming a step where the circuit board transitions from the rigid section to the flexible section; and

a plurality of mechanical restrictive components applied to the one or more transition areas, wherein each of the plurality of mechanical restrictive components is a film of woven glass material impregnated with an adhesive material, wherein at least one of the plurality of mechanical restrictive components fills the step, is on an outermost surface covering at least a portion of the one or more rigid sections, and is on an outermost surface covering at least a portion of the one or more flexible sections, wherein at least two of the plurality of mechanical restrictive components are symmetrically positioned such that a first of the at least two of the plurality of mechanical restrictive components is positioned as an overlay and a second of the at least two of the plurality of mechanical restrictive components is positioned as an underlay.

2. The circuit board of claim 1, wherein the one or more flexible sections comprise a flexible circuit board.

3. The circuit board of claim 1, wherein the one or more flexible sections comprise a stretchable circuit board.

4. The circuit board of claim 1, wherein the film comprise a thickness between 0.01 mils and 20 mils.

5. The circuit board of claim 1, further comprising one or more glass woven sections.

6. The circuit board of claim 1, wherein at least one of the plurality of mechanical restrictive components is continuous across the one or more transition areas.

7. A method of strengthening a circuit board comprising:

forming a first mechanical restrictive component and a second mechanical restrictive component, wherein each of the mechanical restrictive components is a film of woven glass material impregnated with an adhesive material;

obtaining a circuit board that includes a rigid section having a first level, a flexible section having a second level that is different from the first level, and a step defined by the first level and the second level;

applying the first mechanical restrictive component to a transition area of the circuit board where the circuit board transitions from the rigid section to the flexible section, wherein the first mechanical restrictive component fills the step, is on an outermost surface covering at least a portion of the rigid section, and is on an outermost surface covering at least a portion of the flexible section; and

applying the second mechanical restrictive component to the circuit board such that the first and second mechanical restrictive components are symmetrically positioned, wherein one of the mechanical restrictive components is positioned as an overlay and the other of the mechanical restrictive components is positioned as an underlay.

8. The method of claim 7, wherein the circuit board comprises one or more glass woven sections.

9. The method of claim 7, wherein the first mechanical restrictive component is continuous across the transition area of the circuit board.

10. The method of claim 7, wherein the flexible section comprises a flexible circuit board.

11. The method of claim 7, wherein the flexible section comprises a stretchable circuit board.

12. The method of claim 7, wherein the film comprise a thickness between 0.01 mils and 20 mils.

13. A circuit board comprising:

a rigid section having a first thickness;

a flexible section having a second thickness different from the first thickness, and coupling with the rigid section;

a transition area including a plurality of steps where the circuit board transitions from the rigid section to the flexible section; and

a plurality of mechanical restrictive components is symmetrically applied to the transition area of the circuit board, wherein each of the plurality of mechanical restrictive components is a film of woven glass material impregnated with an adhesive material wherein the plurality of mechanical restrictive components is on an outermost surface covering at least a portion of the rigid section, is on an outermost surface covering at least a portion of the flexible section, and fills the plurality of steps, wherein a first of the plurality of mechanical restrictive components is applied as an overlay and a second of the plurality of mechanical restrictive components is applied as an underlay.

14. The circuit board of claim 13, wherein the flexible section comprises a flexible circuit board.

15. The circuit board of claim 13, wherein the flexible section comprises a stretchable circuit board.

16. The circuit board of claim 13, wherein the film comprise a thickness between 0.01 mils and 20 mils.

17. The circuit board of claim 13, wherein the plurality of mechanical restrictive components is continuous across the transition area of the circuit board.

18. The circuit board of claim 13, further comprising one or more glass woven sections.