Patent Publication Number: US-9906879-B2

Title: Solderless module connector for a hearing assistance device assembly

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 14/092,723, entitled “SOLDERLESS HEARING ASSISTANCE DEVICE ASSEMBLY AND METHOD”, filed on Nov. 27, 2013, which is hereby incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     This document relates generally to hearing assistance systems and more particularly to methods and apparatus for solderless module connectors for hearing assistance devices. 
     BACKGROUND 
     Hearing assistance devices, such as hearing aids, include, but are not limited to, devices for use in the ear, in the ear canal, completely in the canal, and behind the ear. Such devices have been developed to ameliorate the effects of hearing losses in individuals. Hearing deficiencies can range from deafness to hearing losses where the individual has impairment responding to different frequencies of sound or to being able to differentiate sounds occurring simultaneously. 
     The hearing aid in its most elementary form usually provides for auditory correction through the amplification and filtering of sound. Hearing aids typically include an enclosure or housing, a microphone, hearing assistance device electronics including processing electronics, and a speaker or receiver. Existing hearing aid circuits and bodies are hand assembled, use individual wires for interconnects, and use a messy and time-consuming soldering process. 
     Accordingly, there is a need in the art for methods and apparatus for improved assembly for hearing assistance devices. 
     SUMMARY 
     Disclosed herein, among other things, are systems and methods for solderless module connectors for hearing assistance devices. One aspect of the present subject matter includes a method of assembling a hearing assistance device. According to various embodiments, the method includes providing a structure including a laser-direct structuring (LDS) portion, and inserting a flexible universal circuit module (UCM) having conductive surface traces and elastomeric backing into the structure. The UCM is electrically connected to the LDS portion using direct compression without the use of wires or solder, according to various embodiments. 
     One aspect of the present subject matter includes a hearing assistance device. According to various embodiments, the hearing assistance device includes a structure including a laser-direct structuring (LDS) portion, and a flexible universal circuit module (UCM) having conductive surface traces and elastomeric backing, the flexible circuit module configured to be inserted into the structure. In various embodiments, the UCM is configured to electrically connect to the LDS portion using direct compression without the use of wires or solder. 
     This Summary is an overview of some of the teachings of the present application and not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details about the present subject matter are found in the detailed description and appended claims. The scope of the present invention is defined by the appended claims and their legal equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a block diagram of a hearing assistance device, according to various embodiments of the present subject matter. 
         FIGS. 2A-2B  illustrate views of a flexible circuit module for a hearing assistance device, according to various embodiments of the present subject matter. 
         FIGS. 3A-3C  illustrate views of a MID housing including conductive surface traces for a hearing assistance device, according to various embodiments of the present subject matter. 
         FIGS. 4-5  illustrate views of a MID housing including a microphone connection for a hearing assistance device, according to various embodiments of the present subject matter. 
         FIGS. 6-7  illustrate views of a MID housing including programming connections for a hearing assistance device, according to various embodiments of the present subject matter. 
         FIGS. 8-10  illustrate views of a MID housing including receiver connections for a hearing assistance device, according to various embodiments of the present subject matter. 
         FIGS. 11-12  illustrate views of a standard product application of a UCM connection, according to various embodiments of the present subject matter. 
         FIGS. 13-14  illustrate views of a custom product application of a UCM connection, according to various embodiments of the present subject matter. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description of the present subject matter refers to subject matter in the accompanying drawings which show, by way of illustration, specific aspects and embodiments in which the present subject matter may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present subject matter. References to “an”, “one”, or “various” embodiments in this disclosure are not necessarily to the same embodiment, and such references contemplate more than one embodiment. The following detailed description is demonstrative and not to be taken in a limiting sense. The scope of the present subject matter is defined by the appended claims, along with the full scope of legal equivalents to which such claims are entitled. 
     The present detailed description will discuss hearing assistance devices using the example of hearing aids. Hearing aids are only one type of hearing assistance device. Other hearing assistance devices include, but are not limited to, those in this document. It is understood that their use in the description is intended to demonstrate the present subject matter, but not in a limited or exclusive or exhaustive sense. Hearing aids typically include an enclosure or housing, a microphone, hearing assistance device electronics including processing electronics, and a speaker or receiver. Hearing assistance devices may include a power source, such as a battery. In various embodiments, the battery may be rechargeable. In various embodiments multiple energy sources may be employed. It is understood that in various embodiments the microphone is optional. It is understood that in various embodiments the receiver is optional. It is understood that variations in communications protocols, antenna configurations, and combinations of components may be employed without departing from the scope of the present subject matter. Antenna configurations may vary and may be included within an enclosure for the electronics or be external to an enclosure for the electronics. Thus, the examples set forth herein are intended to be demonstrative and not a limiting or exhaustive depiction of variations. Existing hearing aid circuits and bodies are hand assembled, use individual wires for interconnects, and use a messy and time-consuming soldering process. 
     Disclosed herein, among other things, are systems and methods for solderless module connectors for hearing assistance devices. One aspect of the present subject matter includes a method of assembling a hearing assistance device. According to various embodiments, the method includes providing a structure including a laser-direct structuring (LDS) portion, and inserting a flexible universal circuit module (UCM) having conductive surface traces and elastomeric backing into the structure. The UCM is electrically connected to the LDS portion using direct compression without the use of wires or solder, according to various embodiments. One aspect of the present subject matter includes a hearing assistance device. According to various embodiments, the hearing assistance device includes a structure including a laser-direct structuring (LDS) portion, and a flexible universal circuit module (UCM) having conductive surface traces and elastomeric backing, the flexible circuit module configured to be inserted into the structure. In various embodiments, the UCM is configured to electrically connect to the LDS portion using direct compression without the use of wires or solder. 
     Disclosed herein, among other things, are systems and methods for solderless assembly for hearing assistance devices. One aspect of the present subject matter includes a hearing assistance device. According to various embodiments, the hearing assistance device includes a MID housing, such as a LDS housing and a flexible circuit module having conductive surface traces and also may have elastomeric backing, the flexible circuit module configured to be inserted into the MID housing. One or more hearing assistance electronic modules are configured to connect to the flexible circuit module using direct compression without the use of wires or solder, in various embodiments. The present subject matter uses molded interconnect device (MID) technology that combines injection-molded thermoplastic parts with integrated electronic circuit traces using selective metallization. One type of MID technology is LDS. In LDS, thermoplastic parts are doped with a metal-plastic additive that can be activated using a laser. The present subject matter contemplates any and all types of MID technology for implementation of the solderless hearing assistance device system. 
       FIG. 1  shows a block diagram of a hearing assistance device  100  according to one embodiment of the present subject matter. In this exemplary embodiment the hearing assistance device  100  includes hearing assistance electronics such as a processor  110  and at least one power supply  112 . In one embodiment, the processor  110  is a digital signal processor (DSP). In one embodiment, the processor  110  is a microprocessor. In one embodiment, the processor  110  is a microcontroller. In one embodiment, the processor  110  is a combination of components. It is understood that in various embodiments, the processor  110  can be realized in a configuration of hardware or firmware, or a combination of both. In various embodiments, the processor  110  is programmed to provide different processing functions depending on the signals sensed from the microphone  130 . In hearing aid embodiments, microphone  130  is configured to provide signals to the processor  110  which are processed and played to the wearer with speaker  140  (also known as a “receiver” in the hearing aid art). 
     Other inputs may be used in combination with the microphone. For example, signals from a number of different signal sources can be detected using the teachings provided herein, such as audio information from a FM radio receiver, signals from a BLUETOOTH or other wireless receiver, signals from a magnetic induction source, signals from a wired audio connection, signals from a cellular phone, or signals from any other signal source. 
     The present subject matter overcomes several problems encountered in assembling hearing assistance devices and their subcomponents. One of these problems is the time consuming, messy process of hand assembly and soldering. Another problem overcome by the present subject matter is the lengthy design time of each hearing aid circuit. Finally, the overall cost of materials, such as high density flex, is reduced by the present subject matter. 
     Currently, the assembly of flexible circuits into hearing aids can be complicated. Once the flexible circuit is inserted into the spine, each limb of the circuit must be bent down and connected to another component. The connection is currently made by direct soldering, such as to a battery contact, or a wire must be soldered to the flexible circuit pad and then run to a second component, such as a push button or microphone. Currently the primary method of soldering wire connections is hand soldering, and this process alone contributes significantly to the time required to make a custom hearing assistance product. In addition, the use of heat in the soldering process can cause component and circuit damage both during assembly and repair. Thus, the current method of using wires and soldering for hearing assistance device component interconnects consumes labor, time, additional parts (wires and additional subassemblies), additional parts cost, additional connection points and increased system volume. It also provides a difficult and messy repair process. Furthermore, the wires must be placed over the spine, taking up valuable space, and can be pulled or broken during the process. 
     Previous solutions to the hand soldering and assembly steps include attempts to reduce the number of wires necessary in standard hearing aid designs, specifically by replacing them with additional flexible circuit limbs. The addition of more limbs leads to even more complex and abstractly shaped circuits. This leads to fewer circuits per panel and consequently a larger numbers of costly circuit panels. The past solutions to reduce the time and effort related to designing flexible circuits have focused on designing a common flexible circuit board between products. A common flexible circuit board is difficult to accomplish due to the diverse hearing aid design shapes, electrical requirements and location of connection points. Previously, when a common design has been successfully developed it has required the removal of a circuit limb for each hearing aid design. This results in wasted flexible circuit material as well as wasted space per panel. There are also efforts made to redesign current product flexible circuit designs in order to fit more circuits per panel. These attempts result in only a few more circuits fitting onto the panel and the cost savings is minimal. This also results in even more circuit design time spent per hearing aid design. 
     The present subject matter provides a hearing aid circuit and body that can be assembled without the need for solder or conductive epoxy. The present subject matter is unique in that it provides a method of assembling a hearing aid circuit to the spine and other components without the need of solder or conductive epoxy by utilizing a high density flexible circuit without wires in combination with a low density MID spine or housing, in various embodiments. Various embodiments of the present subject matter include a solderless microphone connection, solderless DSP module connection, solderless integration of a receiver jack, and solderless integrated programming interface. The present subject matter improves upon previous solutions because it does not require the addition of more wires or flexible circuit limbs. In various embodiments, the method of the present subject matter leads to higher yields of hearing aid components since they are not subjected to soldering temperatures. Additionally, the design time and effort associated with developing new hearing aids is reduced, making assembly and repair substantially easier and quicker, and eliminating the need for circuit limbs leading to more circuits per panel. 
     According to various embodiments, the present subject matter includes four types of solderless assembly connection. The connections are made via direct compression where the MID conductors form a connection with the flex without intermediary materials such as solder or conductive epoxy. The drawings illustrate a custom hearing aid application, but one of skill in the art would understand that the present subject matter is equally applicable to other types of hearing aids, such as those with a standard spine. 
       FIGS. 2A-2B  illustrate views of a flexible circuit module for a hearing assistance device, according to various embodiments of the present subject matter. A DSP module  200  includes an integrated flex connection area  202  having exposed traces. The exposed traces include Nickel Gold plating, in an embodiment. Other types of traces can be used without departing from the scope of the present subject matter. The traces are locate on the edges of the module, in various embodiments. An elastomeric material  204  is located between the flex and the module sides in various embodiments, providing pressure to ensure proper connections. 
       FIGS. 3A-3C  illustrate views of a MID housing  300  including conductive surface traces for a hearing assistance device, according to various embodiments of the present subject matter. The electrical connection with the flex connection area  302  is made with plastic fingers with traces  306  that have been processed using LDS or other three-dimensional (3D) molded interconnect device (MID) technologies to provide both the connection point as well as interconnection to other components, according to various embodiments. The elastomeric material  204  located between the flex and the module sides provides pressure to ensure proper connections, in various embodiments. 
       FIGS. 4-5  illustrate views of a MID housing  300  including a microphone connection for a hearing assistance device, according to various embodiments of the present subject matter. In various embodiments, a connection to a microphone  410  is made directly to the microphone pads. An LDS or other 3D MID technology is used to create metallized contacts  406  that can also function as interconnects to other components, in various embodiments. According to various embodiments, the contacts  406  are integral to the polymer contact fingers which provide one side of the connection. A retention band  412  of irradiated polymer (heat shrink) is applied over the microphone and fingers and heat applied to provide compression, in an embodiment. In another embodiment, the retention is provided using a metal clip  514 . Other retention mechanisms are possible without departing from the scope of the present subject matter. 
       FIGS. 6-7  illustrate views of a MID housing including programming connections for a hearing assistance device, according to various embodiments of the present subject matter. In various embodiments, program connections are made using LDS or other 3D MID technologies to create metallized connection contacts  620  that can also function as interconnects to other components. The MID housing accepts a programming strip  622 , in an embodiment. The connection contacts  620  are integral to the MID housing  300 , in various embodiments. A battery drawer  730  has cam action that provides compression to ensure a proper connection, according to various embodiments. In conjunction with a stereolithography (SLA) shell with module retention features, any component can be replaced and sent to a central reprocessing point for recovery and possible reuse, all without component or shell damage. 
       FIGS. 8-10  illustrate views of a MID housing  300  including receiver connections for a hearing assistance device, according to various embodiments of the present subject matter. To acoustically isolate a microphone and a receiver, no rigid connections are made to the receiver, in various embodiments. Flexible wires can be used and twisted to afford electromagnetic interference (EMI) protection as well, in various embodiments. According to various embodiments, LDS is used to provide a receptacle (via)  802 . In various embodiments, the receptacle  802  is lasered at the same time as a traces pattern. In one embodiment, the receptacle  802  and custom plug  904  are smaller than currently available receiver connections. In order to provide compression in the connection, twisted wire interconnect (TWI) pins  1006  are used with a custom mold to create a jack/connector, in various embodiments. The TWI plug includes wires  1002  to the receiver and a molded grip  1004 , in various embodiments. Other direct insertion mechanisms are possible without departing from the scope of the present subject matter. 
     The present subject matter provides for specific connection schemes for the UCM, components and devices to solderlessly connect to a unifying LDS structure. In various embodiments, a system that incorporates this connector as well as solderless microphone, programming and accessory connections is provided. The present subject matter has application for both Standard and Custom hearing aids, and is superior to previous solutions in that it decreases the number of heat cycles, touch points and increases the ability to reuse more components. The present subject matter provides an injection molded plastic structure made with an LDS capable plastic. In various embodiments, it is included in an area of a larger part and the entire part is LDS capable. The UCM includes a ball grid array (BGA) format, in an embodiment. The UCM is reflowed to a simple 2 layer flex that is long enough to wrap up both sides of the UCM and partially across the back, in an embodiment. The flex along the sides and back has a specified thickness of pressure sensitive adhesive (0.005 thick in an embodiment) applied so that it holds the flex to the sides and back. The flex along the sides is designed to provide exposed connective traces that are finished with a corrosion resistant finish similar to standard PCB pad finishes, in various embodiments. The UCM with flex is inserted into the LDS structure, and the LDS structure is designed to have conductive pressure points that align with conductive traces on the UCM flex circuit, in various embodiments. The LDS conductive traces also have a corrosion resistant finish, in an embodiment. The design of the LDS structure also provides a compressive force on the UCM with flex, in various embodiments. Additional retention features can be incorporated as needed. 
       FIGS. 11 and 12  show an example in a standard product application of the present subject matter, showing an LDS structure  1100  and a UCM  1200 .  FIGS. 13 and 14  show an embodiment of a custom application. This subject matter can be used as a means of connection without solder of the UCM. In various embodiments the connections made by the LDS structure to other solderless connection structures for microphone, six pin jack, programming, TC, switches, etc., can be used. The present subject matter provides for the ability to replace or salvage the UCM. In the case of a defective UCM, the time to replace would only be a fraction of the time that would be need to rewire as in the case of a custom repair. The UCM can be removed without damage, in various embodiments. Additionally, using the solderless connection to the UCM in standard products provides for the replacement of the UCM rather than having to replace the entire electronics system (the radio section and the entire high density flex, SMT switches, program jack etc.). When in conjunction with other solderless connectors made using LDS, the assembly time and component damage can be greatly reduced. The present subject matter provides for recovering and replacing of most the higher cost components possible without unnecessary damage or time required. 
     The present subject matter can be used for standard fit as well as custom hearing aids, in various embodiments. Modules can be used in place of or in combination with flexible circuits, according to various embodiments. Benefits of the present subject matter include substantial assembly time and cost savings. Furthermore, the use of a common flexible circuit board for a variety of spine designs leads to less design time required for each hearing aid circuit style. The elimination of soldered wires as well as flexible circuit limbs leads to smaller hearing aids, in various embodiments. 
     Various embodiments of the present subject matter support wireless communications with a hearing assistance device. In various embodiments the wireless communications can include standard or nonstandard communications. Some examples of standard wireless communications include link protocols including, but not limited to, Bluetooth™, IEEE 802.11 (wireless LANs), 802.15 (WPANs), 802.16 (WiMAX), cellular protocols including, but not limited to CDMA and GSM, ZigBee, and ultra-wideband (UWB) technologies. Such protocols support radio frequency communications and some support infrared communications. Although the present system is demonstrated as a radio system, it is possible that other forms of wireless communications can be used such as ultrasonic, optical, infrared, and others. It is understood that the standards which can be used include past and present standards. It is also contemplated that future versions of these standards and new future standards may be employed without departing from the scope of the present subject matter. 
     The wireless communications support a connection from other devices. Such connections include, but are not limited to, one or more mono or stereo connections or digital connections having link protocols including, but not limited to 802.3 (Ethernet), 802.4, 802.5, USB, SPI, PCM, ATM, Fibre-channel, Firewire or 1394, InfiniBand, or a native streaming interface. In various embodiments, such connections include all past and present link protocols. It is also contemplated that future versions of these protocols and new future standards may be employed without departing from the scope of the present subject matter. 
     It is understood that variations in communications protocols, antenna configurations, and combinations of components may be employed without departing from the scope of the present subject matter. Hearing assistance devices typically include an enclosure or housing, a microphone, hearing assistance device electronics including processing electronics, and a speaker or receiver. It is understood that in various embodiments the receiver is optional. Antenna configurations may vary and may be included within an enclosure for the electronics or be external to an enclosure for the electronics. Thus, the examples set forth herein are intended to be demonstrative and not a limiting or exhaustive depiction of variations. 
     It is further understood that any hearing assistance device may be used without departing from the scope and the devices depicted in the figures are intended to demonstrate the subject matter, but not in a limited, exhaustive, or exclusive sense. It is also understood that the present subject matter can be used with a device designed for use in the right ear or the left ear or both ears of the user. 
     It is understood that the hearing aids referenced in this patent application include a processor. The processor may be a digital signal processor (DSP), microprocessor, microcontroller, other digital logic, a separate analog and separate digital chip, or combinations thereof. The processing of signals referenced in this application can be performed using the processor. Processing may be done in the digital domain, the analog domain, or combinations thereof. Processing may be done using subband processing techniques. Processing may be done with frequency domain or time domain approaches. Some processing may involve both frequency and time domain aspects. For brevity, in some examples drawings may omit certain blocks that perform frequency synthesis, frequency analysis, analog-to-digital conversion, digital-to-analog conversion, amplification, audio decoding, and certain types of filtering and processing. In various embodiments the processor is adapted to perform instructions stored in memory which may or may not be explicitly shown. Various types of memory may be used, including volatile and nonvolatile forms of memory. In various embodiments, instructions are performed by the processor to perform a number of signal processing tasks. In such embodiments, analog components are in communication with the processor to perform signal tasks, such as microphone reception, or receiver sound embodiments (i.e., in applications where such transducers are used). In various embodiments, different realizations of the block diagrams, circuits, and processes set forth herein may occur without departing from the scope of the present subject matter. 
     The present subject matter is demonstrated for hearing assistance devices, including hearing aids, including but not limited to, behind-the-ear (BTE), in-the-ear (ITE), in-the-canal (ITC), receiver-in-canal (RIC), completely-in-the-canal (CIC) or invisible-in-canal (IIC) type hearing aids. It is understood that behind-the-ear type hearing aids may include devices that reside substantially behind the ear or over the ear. Such devices may include hearing aids with receivers associated with the electronics portion of the behind-the-ear device, or hearing aids of the type having receivers in the ear canal of the user, including but not limited to receiver-in-canal (RIC) or receiver-in-the-ear (RITE) designs. The present subject matter can also be used in hearing assistance devices generally, such as cochlear implant type hearing devices and such as deep insertion devices having a transducer, such as a receiver or microphone, whether custom fitted, standard, open fitted or occlusive fitted. It is understood that other hearing assistance devices not expressly stated herein may be used in conjunction with the present subject matter. 
     In addition, the present subject matter can be used in other settings in addition to hearing assistance. Examples include, but are not limited to, telephone applications where noise-corrupted speech is introduced, and streaming audio for ear pieces or headphones. 
     This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. The scope of the present subject matter should be determined with reference to the appended claims, along with the full scope of legal equivalents to which such claims are entitled.