Patent Publication Number: US-11647347-B2

Title: Method of manufacturing a faceplate for a hearing device

Description:
The invention relates to a method of manufacturing a faceplate for a hearing device comprising an antenna. 
     BACKGROUND 
     Hearing devices which are to be worn at least partially in the ear canal comprise a housing or shell with an outwardly facing opening which is covered by a faceplate. ITE (“in-the-ear”) hearing devices are examples of such hearing devices. For wireless applications, the hearing devices may comprise an antenna which can be integrated within the faceplate. 
     US 2017/0150278 A1 relates to an ITE hearing aid wherein a magnetic loop antenna is integrated within the faceplate. 
     EP 3 110 174 A1 relates to an ITE hearing aid comprising a faceplate in which an antenna is embedded or in-molded. The antenna may be designed as a loop antenna and it may include a flexible printed circuit board (“PCB”). 
     WO 2017/0153020 A1 relates to an ITE hearing aid comprising an annular antenna which is arranged on the faceplate or parallel to the faceplate. 
     U.S. Pat. No. 8,494,197 B2 relates to an ITE hearing aid with a loop antenna on a flexible PCB which loops around the battery; the PCB is inserted into a trench provided at the interior side of the faceplate in such a manner that the PCB is oriented perpendicular to the faceplate. 
     BRIEF SUMMARY 
     It is an object of the invention to provide an efficient and accurate method of manufacturing a faceplate for a hearing device which is to be worn at least partially in the ear canal, wherein an antenna is integrated within the faceplate. 
     According to the invention, this object is achieved by methods as defined in the claims. 
     The invention is beneficial in that it allows for an accurate and consistent placement of the antenna within the hearing device; in addition, assembly efficiency and serviceability may be improved; in particular, assembly time may be reduced, accuracy of assembly may be increased, serviceability may be improved, as well as reliability of antenna performance. 
     Preferred embodiments of the invention are defined in the dependent claims. 
     Preferred embodiments of one method may include at least one the following aspects: 
     The faceplate insertion part may comprise engagement structures for holding down the antenna PCB towards the faceplate base part, wherein the engagement structures of the faceplate insertion part may comprise a plurality of tabs which extend towards the exterior of the hearing device in a direction perpendicular to second surface and which are circumferentially spaced apart. 
     The first surface of the faceplate base part and the second surface of the faceplate insertion part may be inclined in parallel directions so that the second surface of the faceplate insertion part presses the antenna PCB snugly towards the first surface of faceplate base part. 
     The faceplate base part and the faceplate insertion part may comprise mating features so as to align the faceplate base part and the faceplate insertion part relative to each other. 
     An adhesive may be applied to at least part of the mating features so as to fix the faceplate insertion part to the faceplate base part. 
     An adhesive may be applied to the antenna PCB so as to fix the antenna PCB between the second surface of the faceplate insertion part and the first surface of the faceplate base part. 
     The first surface and the second surface may be complementary. 
     The first surface may extend along at least part of the circumference of the faceplate base part, and the second surface may extend along at least part of the circumference of the faceplate insertion part. 
     The first surface of the faceplate base part may face the interior of the hearing device and the second surface of the faceplate insertion part may face the exterior of the hearing device, so as to form a trench for receiving the antenna PCB; he first surface and the second surface may be substantially orthogonal to the laterally oriented side of the faceplate. 
     The faceplate base part may comprise the laterally oriented side of the faceplate and may be located laterally with regard to the faceplate insertion part. 
     The faceplate insertion part may be fixed to the faceplate base part by an adhesive. 
     Preferred embodiments of another method may include at least one of the following aspects: 
     The plastic frame may extend along more than half of the length of the antenna PCB; in particular, the plastic frame may extend along the entire length of the flexible antenna PCB. 
     The contour of the plastic frame may substantially equal the contour of the antenna PCB. 
     The antenna PCB may be first inserted into the trench, and then the plastic frame may be inserted into the trench. 
     The antenna PCB and the plastic frame may be fixed by an adhesive within the trench. 
     The antenna PCB may be first fixed by the adhesive to the first surface, and then the plastic frame may be fixed to the antenna PCB and the second surface. 
     The antenna PCB may be first fixed to the plastic frame, and then the plastic frame, together with the antenna PCB, may be inserted into the trench. 
     The plastic frame, together with the antenna PCB fixed to the plastic frame, may be fixed within the trench by an adhesive. 
     The antenna PCB may be wrapped around the plastic frame for fixing the antenna PCB to the plastic frame. 
     The antenna PCB and the plastic frame may comprise alignment features for aligning the antenna PCB to the plastic frame; the alignment features of the plastic frame may be configured to fix the antenna PCB to the plastic frame. 
     The antenna PCB may be fixed to the plastic frame by an adhesive. 
     Alternatively, the plastic frame may extend along less than half of the length of the antenna PCB. 
     The plastic frame may comprise engagement structures configured to engage with mating engagement structures of the antenna PCB to hold down and locate the antenna PCB within the trench. 
     The engagement structures of the plastic frame may comprise tabs. 
     The antenna PCB may be first inserted into the trench, and then the plastic frame may be inserted into the trench. 
     The antenna PCB and the plastic frame may be fixed by an adhesive within the trench. 
     The antenna PCB may be first fixed by the adhesive to the first surface, and then the plastic frame may be fixed by the adhesive to the antenna PCB and the second surface. 
     The first surface of the faceplate base part may face the interior of the hearing device, and the second surface of the faceplate base part may face the exterior of the hearing device, wherein the first surface and the second surface may be substantially orthogonal to the laterally oriented side of the faceplate. 
     Preferred embodiments of both methods may include at least one the following aspects: 
     The antenna PCB may be flexible. 
     The antenna may be integrated within the faceplate in a manner so as to follow the contour of the laterally oriented side of the faceplate to maximize radiation gain, wherein the antenna may comprise a conductor trace located at the lateral edge of the antenna PCB. 
     The antenna PCB may be oriented orthogonal to the laterally oriented side of the faceplate. 
     The antenna PCB may be folded around a battery and an electronics subassembly of the hearing device. 
     The antenna may be a dipole antenna, which preferably has two arms with an end gap between the ends of the arms. 
     A medial edge of the antenna PCB may be flush with a medially oriented side of the faceplate once the antenna PCB is fixed within the trench. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Hereinafter, examples of the invention will be illustrated by reference to the attached drawings, wherein: 
         FIGS.  1 A to  1 C  are perspective views of a first example of a faceplate with an antenna, wherein an initial stage, an intermediate stage and a final stage, respectively, of an assembly process are shown; 
         FIGS.  2 A to  2 C  are views similar to  FIGS.  1 A to  1 C , wherein a second example is shown; 
         FIGS.  3 A to  3 C  are views similar to  FIGS.  1 A to  1 C , wherein a third example is shown; 
         FIGS.  4 A to  4 C  are views similar to  FIGS.  1 A to  1 C , wherein a fourth example is shown; 
         FIG.  4 D  shows an elevated view of the assembled faceplate; and 
         FIGS.  5 A to  5 C  are perspective views of a fifth example of a faceplate during different intermediate assembly stages. 
     
    
    
     DETAILED DESCRIPTION 
     As used hereinafter, “hearing devices” includes all kinds of hearing devices which are configured to be worn at least partially in the ear canal, such as ITE (In The Ear) hearing devices, ITC hearing devices (in-the canal) or CIC (completely-in-the-canal) hearing devices. 
     As used hereinafter, “lateral” relates to a direction away from the tympanic membrane, when the hearing device is worn at least partially in the ear canal, and “medial” relates to a direction towards the tympanic membrane, when the hearing device is worn at least partially in the ear canal. 
     As used hereinafter, “outwardly” relates to a direction perpendicular to the lateral-medial direction and away from the center of the faceplate, and “inwardly” relates to a direction perpendicular to the lateral-medial direction and towards the center of the faceplate. 
     As used hereinafter, “substantially orthogonal” relates to an angular range from 75 to 105 degrees, and “substantially parallel” relates to an angular range from −15 to +15 degrees. 
     The invention relates to the manufacturing of faceplates for hearing devices which are to be worn at least partially in the ear canal, wherein the faceplate is configured to cover a lateral opening of the housing of the hearing device, with the faceplate having one side which is laterally oriented when the hearing device is worn at least partially in the ear canal. The housing may be a standard shell (which is not individually shaped) or a customized shell (which is shaped according to the individual shape of the user&#39;s ear canal). 
     An antenna is provided on a PCB, which may be flexible, and is integrated within the faceplate. In some implementations, the antenna is designed for operation in the 2.4 to 2.5 GHz ISM (Industrial, Scientific, and Medical) band. In some implementations, the antenna is a dipole antenna. In some implementations, the antenna is folded around a battery and an electronic sub-assembly of the hearing device. 
     In some implementations, the antenna is integrated within the faceplate in a manner so as to follow the contour of the laterally oriented side of the faceplate so as to maximize radiation gain. 
     In some implementations, the antenna PCB is oriented substantially orthogonal to the laterally oriented side of the faceplate. 
     According to a first aspect of the invention, the faceplate is made of two initially separate parts, namely a faceplate base part and a faceplate insertion part, wherein the two parts, once assembled, together form a trench for the antenna. The antenna is first inserted into the faceplate base part so that the antenna PCB extends along a first (typically inner) surface. Then the faceplate insertion part is inserted into the faceplate base part so that a second (typically outer) surface of the faceplate insertion part pushes the PCB against the (inner) surface of the faceplate base part, with the two surfaces then defining a trench for the PCB. The faceplate insertion part is fixed within the faceplate base part so as to form the faceplate. 
       FIGS.  1 A-C  and  2 A-C relate to two different examples of this first aspect, wherein an antenna PCB  12  is integrated within a faceplate  10 , wherein the faceplate  10  is made of two initially separate parts, namely a faceplate base part  14  and a faceplate insertion part  16 , wherein the two parts  14  and  16  cooperate to form a trench in which the antenna PCB  12  is fixed (while in  FIGS.  1 A-C  and  2 A-C only the PCB  12  is shown, the electrical conductors actually forming the antenna on the PCB  12  are not shown). 
     The faceplate base part  14  comprises an inwardly facing first surface  18  (hereinafter “inner surface  18 ”), and the faceplate insertion part  16  comprises an outwardly facing second surface  20  (hereinafter “outer surface  20 ”) which may be complementary with the first surface  18 . The inner surface  18  extends along at least part of the circumference  22  of the faceplate base part  14  (and is located close to a peripheral surface  25  of the faceplate base part  14 , and the outer surface  20  preferably extends along at least part of the circumference  24  of the faceplate insertion part  16 . 
     In the examples shown in  FIGS.  1 A-C  and  2 A-C, the inner surface  18  extends along almost the entire circumference  22  of the faceplate base plate  14 , and the outer surface  20  extends along almost the entire circumference  24  of the faceplate insertion part  16 . 
     The faceplate base part  14  comprises a laterally oriented side  26  of the faceplate  10  and is located laterally with regard to the faceplate insertion part  16  when the hearing device is worn at least partially in the ear canal. The medial-axial direction is indicated in the Figures by an arrow  28 ; this direction also corresponds to the longitudinal direction of the hearing device. 
     The inner surface  18  and the outer surface  20  are oriented substantially parallel to the medial-lateral direction  28  and thus are substantially orthogonal to the laterally oriented side  26  of the faceplate  10 . 
     In some implementations, a medial edge  30  of the antenna PCB  12  is flush with a medially oriented side  32  of the faceplate  10  after assembly (see  FIGS.  1 C and  2 C ). 
     In the examples shown in  FIGS.  1 A-C  and  2 A-C; the outer surface  20  of the faceplate insertion part  16  forms a peripheral surface of the faceplate insertion part  16  (in other words, it forms the outer boundary of the faceplate insertion part  16 ). 
     In some implementations, the antenna on the PCB  12  is a dipole antenna which has two arms with an end gap formed between the ends of the arms (not shown in  FIGS.  1 A-C  and  2 A-C). 
     In some implementations, the antenna PCB  12  is made of polyimide and copper layers and gold plating. 
     In the examples illustrated in  FIGS.  1 A-C  and  2 A-C, the antenna PCB  12  and the faceplate insertion part  16  are inserted into the faceplate base part  14  from the medial side of the faceplate  10  (which is the side of the faceplate  10  which faces the tympanic membrane when the hearing device is worn at least partially in the ear canal). As can be seen in  FIGS.  1 A,  1 B and  2 A,  2 B , in a first assembly step the antenna PCB  12  is inserted into the faceplate base part  14  in such a manner that the antenna PCB  12  extends along the inner surface  18 . 
     In a second assembly step (see  FIGS.  1 C and  2 C ), the faceplate insertion part  16  is inserted into the faceplate base part  14  in such a manner that the outer surface  20  pushes the antenna PCB  12  against the first surface  18  of the faceplate base part  14 . Thereby the inner surface  18  and the outer surface  20  define a trench for the antenna PCB  12 , with the inner surface  18  and the outer surface  20  acting as the two walls of the trench. 
     In a third assembly step, the faceplate insertion part  16  is fixed within the faceplate base part  14  so as to form the faceplate  10 . 
     In the example of  FIGS.  1 A to  1 C , the faceplate insertion part  16  comprises engagement structures  36  for holding down the antenna PCB  12  towards the faceplate base part  14  when the faceplate insertion part  16  has been inserted into the faceplate base part  14 . In the example shown in  FIGS.  1 A to  1 C , the engagement structures  36  comprise a plurality of tabs  38  which extend outwardly in a direction essentially perpendicular to the second surface  20 , with the tabs  38  being circumferentially spaced apart. 
     The inner surface  18  of the faceplate base part  14  and the outer surface  20  of the faceplate insertion part  16  may be inclined in parallel directions so that the outer surface  20  presses the antenna PCB  12  snugly towards the inner surface  18 . 
     The engagement structures  36  allow for fixation of the antenna PCB  12  in the medial-lateral direction  28  without a need for use of an adhesive, etc. This allows for an option to remove the antenna PCB  12  from the faceplate  10 , for example, for replacement. 
     In the examples illustrated in  FIGS.  1 A-C  and  2 A-C, the faceplate insertion part  16  may be fixed to the faceplate base part  14  by an adhesive. To this end, adhesive is applied to the faceplate base part and/or the faceplate insertion part  16  prior to inserting the faceplate insertion part  16  into the faceplate base part  14 . 
     In the example of  FIGS.  2 A to  2 C  the faceplate base part  14  and the faceplate insertion part  16  comprise mating features  40  and  42  for aligning the faceplate base part  14  and the faceplate insertion part  16  relative to each other. In the illustrated example, the mating features are implemented as grooves  40  and complementary projections  42 . 
     An adhesive may be applied at least part of the mating features  40 ,  42  so as to fix the faceplate insertion part  16  to the faceplate base part  14 . 
     In the illustrated example, the faceplate insertion part  16  is not provided with the engagement structures  36  of the example of  FIGS.  1 A to  1 C . Accordingly, the antenna PCB  12  may be fixed to the faceplate  10  to the applying an adhesive to the antenna PCB  12  so as to fix the PCB of the antenna PCB  12  between the outer surface  20  of the faceplate insertion part  16  and the inner surface  18  of the faceplate base part  14 . 
     It is noted that in the first assembly step in both examples elastic forces in antenna PCB  12  resulting from the bending of the antenna PCB  12  push the antenna PCB  12  against the inner surface  18  of the faceplate base part  14 , so that the faceplate insertion part  14  can be easily inserted into the faceplate base part  14  without a need to first fix the antenna PCB  12  to the inner surface  18 . 
     According to a second aspect of the invention, a faceplate base part comprising a trench defined by a first surface and a second surface and a plastic frame are provided. The antenna PCB is inserted into the trench of the faceplate base part so that that the antenna PCB extends along the first surface and the antenna PCB is fixed to the faceplate base part. The plastic frame is inserted into the trench, together with the antenna PCB or after the antenna PCB has been inserted into the trench, so as to press the PCB against the first surface along at least part of its length, with the plastic frame abutting the second surface. The first and second surfaces form the walls of the trench, one representing an inner wall and the other representing an outer wall. 
     Three different examples of such assembly method are illustrated in  FIGS.  3 A-C ,  FIGS.  4 A-D  and  FIGS.  5 A-C , wherein the trench for receiving the antenna PCB  12  is not formed by cooperation of two separate parts of the faceplate as in the previously discussed examples, but rather the trench is already provided initially in the faceplate base part  114 , so that no baseplate insertion part is required to form the trench. In other words, the faceplate base part comprises a trench  150  which is defined by a first surface (or wall)  118  and a second surface (or wall)  120 . The baseplate insertion part is replaced by a plastic frame which serves to press the antenna PCB against the first surface  118  along at least part of its length, with the plastic frame abutting the second surface  120 . 
     In the examples of  FIGS.  3 A-C  and  4 A-D, the antenna PCB  12  is first inserted into the trench  150  and thereafter the plastic frame is inserted into the trench; according to the example illustrated in  FIGS.  5 A-C , the antenna PCB  12  is first fixed to the plastic frame and then the antenna PCB and the plastic frame are together inserted into the trench. In all cases, the antenna PCB is finally fixed to the faceplate base part within the trench. 
     In the example illustrated in  FIGS.  3 A to  3 C  the plastic frame  160  extends along more than half of the length of the PCB of the antenna PCB  12 , and, as illustrated in  FIGS.  3 A to  3 C  it may extend along the entire length of the antenna PCB  12 . The plastic frame  160  may also extend in the region  34  between the two antenna feedpoints  12 A,  12 B of the antenna PCB  12  so as to form a closed frame. The contour of the plastic frame  160  may be substantially equal to contour of the antenna PCB  12  so as to provide for full support for the antenna PCB  12 . 
     In the example of  FIGS.  3 A to  3 C  the antenna  12  is inserted into the trench  150  as a first assembly step and then is fixed by an adhesive to the first surface  118  (which forms the inwardly facing wall of the trench  150 ), see  FIGS.  3 A and  3 B . In a second assembly step, the plastic frame  160  is inserted into the trench  150  at a position inwardly with regard to the antenna PCB  12  and then is fixed by an adhesive to the antenna PCB  12  and to the second surface  120  (which forms the outwardly facing wall of the trench  150 ), see  FIGS.  3 B and  3 C . 
     The main difference of the example shown in  FIGS.  4 A to  4 D  to the previous example is that the plastic frame  260  extends along less than half of the length of the antenna PCB  212  and that the plastic frame  260  comprises engagement structures  236  configured to engage with mating structures  237  of the antenna PCB  212  so as to hold down and locate the antenna PCB  212  within the trench  150  of the faceplate base part  114 . In the example of  FIGS.  4 A to  4 C  the engagement structures  236  of the plastic frame  260  comprises a plurality of tabs  238 , and the antenna PCB  212  comprises mating cutouts  235 . 
     As in the example of  FIGS.  3 A- 3 C , the antenna PCB  212  is first inserted into the trench  150  and is fixed by an adhesive, and then the plastic frame  260  is inserted into the trench and is fixed by the adhesive to the antenna PCB  212  and the second surface  120 . An elevated view of the medial side  132  of the faceplate  110  after assembly is shown in  FIG.  4 D . 
     Preferably, the plastic frame  260  is present only in regions of the antenna PCB  212  where the impact of RF performance is expected to be critical. 
     The main difference of the example illustrated in  FIGS.  5 A to  5 C  with regard to the example illustrated in  FIGS.  3 A to  3 C  is that the antenna PCB  312  is first fixed to the plastic frame  360  prior to inserting the plastic frame  360  and the antenna PCB  312  into the trench  150  of the faceplate base part  114 . The antenna PCB  312  and the plastic frame  360  comprise mating alignment features for aligning the antenna PCB  312  to the plastic frame  360 . In addition, the alignment features of the plastic frame  360  may serve to fix the antenna PCB  312  to the plastic frame  360 . Alternatively or in addition, the antenna PCB  312  may be fixed to the plastic frame  360  by an adhesive. As in the example of  FIGS.  3 A to  3 C , the plastic frame  360  stands along the entire length of the antenna PCB  312  and also extends across the region  34  between the antenna feed points  312 A,  312 B. In the example illustrated in  FIGS.  5 A to  5 C , the alignment structures comprise cutouts/openings  335  in the antenna PCB  312  and mating projections  338  at the plastic frame  360 . 
     The plastic frame  360 , together with the antenna PCB  312  fixed to the plastic frame  360 , is finally fixed within the trench  150  by an adhesive. 
     As in the example of  FIGS.  3 A to  3 C  the contour of the plastic frame  360  substantially equals to the contour of the antenna PCB  312 .