METHOD OF FABRICATING A MINIATURE DEVICE HAVING AN ACOUSTIC DIAPHRAGM

• US 20180338207A1
• Filed: 05/17/2017
• Published: 11/22/2018
• Est. Priority Date: 05/17/2017
• Status: Active Grant

• Current Assignee: Bose Corporation
• Original Assignee: Bose Corporation
• Inventors: Nath, Prateek, Prevoir, Shawn, Bushko, Wit
• Granted Patent: US 10,499,159 B2
• Time in Patent Office: Days
• CPC Class Codes: B29C 65/4845 Radiation curing adhesives, e.g. UV light curing adhesives
• CPC Class Codes: B29C 66/731 characterised by the intensive physical properties of the material of the parts to be joined
• CPC Class Codes: B29K 2083/00 Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material
• CPC Class Codes: B29K 2105/0097 Glues or adhesives, e.g. hot melts or thermofusible adhesives
• CPC Class Codes: B29K 2995/0001 having particular acoustical properties
• CPC Class Codes: B29L 2031/3418 Loud speakers
• CPC Class Codes: H04R 2231/001 Moulding aspects of diaphragm or surround
• CPC Class Codes: H04R 2231/003 Manufacturing aspects of the outer suspension of loudspeaker or microphone diaphragms or of their connecting aspects to said diaphragms
• CPC Class Codes: H04R 2307/00 Details of diaphragms or cones for electromechanical transducers, their suspension or their manufacture covered by H04R7/00 or H04R31/003, not provided for in any of its subgroups
• CPC Class Codes: H04R 2307/025 Diaphragms comprising polymeric materials
• CPC Class Codes: H04R 31/003 for diaphragms or their outer suspension
• CPC Class Codes: H04R 7/04 Plane diaphragms
• CPC Class Codes: H04R 7/20 Securing diaphragm or cone resiliently to support by flexible material, springs, cords, or strands
• CPC Class Codes: H04R 9/06 Loudspeakers

Abstract

A method of forming a device having a compliant member includes providing an elastomeric layer in an uncured state. The elastomeric layer is pre-cured to increase its viscosity. Subsequently, a bobbin and housing, each having an end, can be positioned such that their ends extend at least partially into the elastomeric layer. The elastomeric layer is cured to secure it to the bobbin housing. Examples of pre-cure and cure operations include one or more of a thermal cure, evaporative cure and ultraviolet cure, and the application of moisture, microwave energy and chemical additive. Due to the increased viscosity after the pre-cure, the migration of elastomeric material is substantially reduced relative to an uncured elastomeric material. The reduction in elastomeric material migration results in smaller menisci formed along the walls of the housing and bobbin, and reduced thinning of the compliant member formed at their ends.

Claims

1. A method of fabricating a device having a compliant member, comprising:

providing an elastomeric layer in an uncured state;

pre-curing the elastomeric layer to increase a viscosity of the elastomeric layer;

positioning one or more of a bobbin and a housing each having an end such that the end of the one or more of a bobbin and a housing extends at least partially into the elastomeric layer; and

curing the elastomeric layer such that the elastomeric layer is secured to the one or more of the bobbin and the housing.

2. The method of claim 1 wherein the pre-curing of the elastomeric layer comprises applying heat to the elastomeric layer to increase a temperature of the elastomeric layer to a first temperature.

3. The method of claim 2 wherein the curing of the elastomeric layer comprises applying heat to the elastomeric layer to increase the temperature of the elastomeric layer to a second temperature that is greater than the first temperature.

4. The method of claim 3 wherein the pre-curing occurs for a first duration and the curing occurs for a second duration, and wherein the first duration is less than the second duration.

5. The method of claim 1 wherein the pre-curing comprises irradiating the elastomeric layer with ultraviolet light for a first duration.

6. The method of claim 5 wherein the curing comprises irradiating the elastomeric layer with ultraviolet light for a second duration and wherein the second duration is greater than the first duration.

7. The method of claim 1 wherein the pre-curing of the elastomeric layer comprises irradiating the elastomeric layer with ultraviolet light at a first irradiance and the curing of the elastomeric layer comprises irradiating the elastomeric layer with ultraviolet light at a second irradiance, and wherein the second irradiance is greater than the first irradiance.

8. The method of claim 1 wherein the pre-curing comprises applying heat to the elastomeric layer and irradiating the elastomeric layer with ultraviolet light.

9. The method of claim 1 wherein the curing of the elastomeric layer comprises applying heat to the elastomeric layer and irradiating the elastomeric layer with ultraviolet light.

10. The method of claim 1 wherein the elastomeric layer is secured to the bobbin and the housing, the method further comprising removing a portion of the elastomeric layer that extends outside a diameter of the housing.

11. The method of claim 1 wherein the elastomeric layer in an uncured state comprises liquid silicone rubber.

12. The method of claim 1 wherein positioning one or more of a bobbin and a housing further comprises positioning the bobbin inside the housing.

13. A device comprising:

a compliant member having a substantially planar shape and formed of a single layer of a cured elastomeric material; and

one or more of a bobbin and a housing each having an end that extends at least partially into the compliant member, wherein the elastomeric material adheres to a portion of the housing and/or bobbin at the end of the housing and/or bobbin to form a meniscus having a height defined along a wall of the housing and/or bobbin and wherein the height of the meniscus is less than a height of a meniscus formed along the wall of the housing and/or bobbin for an uncured state of the elastomeric material.

14. The device of claim 13 wherein the housing is a tube having an opening at the end.

15. The device of claim 13 wherein the elastomeric material comprises a silicone rubber.

16. The device of claim 13 wherein the complaint member includes a meniscus formed at each of an inner wall surface of the housing and/or bobbin and an outer wall surface of the housing and/or bobbin.

17. A microspeaker device comprising:

an acoustic diaphragm having a substantially planar shape and formed of a single layer of a cured elastomeric material;

a housing having an end extending at least partially into the single layer, wherein the single layer adheres to a portion of the housing at the end of the housing to form a first meniscus having a height defined along a wall of the housing, wherein the height of the first meniscus is less than a height of a meniscus along the wall of the housing for an uncured state of the elastomeric material;

a bobbin disposed inside the housing and having a surface and an end extending at least partially into the single layer, wherein the single layer adheres to a portion of the bobbin at the end of the bobbin to form a second meniscus having a height defined along a wall of the bobbin, wherein the height of the second meniscus is less than a height of a meniscus along the wall of the bobbin for the uncured single layer of the elastomeric material; and

a coil wound on the surface of the bobbin.

18. The microspeaker device of claim 17 wherein the first meniscus comprises a first inner meniscus having a height along an inner wall surface of the housing and a first outer meniscus having a height along an outer wall surface of the housing and wherein the second meniscus comprises a second inner meniscus having a height along an inner wall surface of the bobbin and a second outer meniscus having a height along an outer wall surface of the bobbin.

19. The microspeaker of claim 17 wherein the housing and the bobbin are formed of different materials.

20. The microspeaker of claim 17 wherein the height of the first meniscus is different from the height of the second meniscus.