Patent ID: 12231853

The figures are schematic and simplified for clarity, and they just show details which are essential to the understanding of the disclosure, while other details are left out.

Further scope of applicability of the present disclosure will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure will become apparent to those skilled in the art from this detailed description.

MODE(S) FOR CARRYING OUT THE INVENTION

FIGS.1a-1bshow cross sections of two embodiments of a completely in the ear canal type hearing aid comprising a battery and a folded substrate for carrying components of the hearing aid. The embodiments of a hearing aid inFIGS.1a-1bcomprise a Housing enclosing a Folded substrate comprising a number of interconnected electronic components including a Loudspeaker (receiver) unit for presenting an acoustic output signal to user via a Loudspeaker outlet attached to or forming part of a flexible Dome element for locating the hearing aid in an ear canal of a user. In practice, other components (e.g. discrete or integrated circuit components) in addition to the Loudspeaker (receiver) unit are typically located on the Folded substrate. The Housing further encloses a Battery for energizing the components of the hearing aid enclosed in the Housing and a Microphone unit for picking up a sound from the environment via a Microphone inlet. The Microphone unit, the Battery and the Loudspeaker (receiver) unit are electrically connected to the folded substrate via connecting wires and Solder contacts on the substrate. A Folding zone (a part of the planar substrate mechanically affected by the folding, e.g. by contributing to the curvature) is indicated on the folded substrate. The Folding zone is limited by the dashed line and the nearest outer boundary (the Folding zone typically running on both parts of the planar substrate symmetrically around a folding line represented by the outer outline of the folded substrate next to the dashed line, as e.g. illustrated inFIGS.5a-5band6a-6b). In the embodiment ofFIG.1a, the outer edges of the Folded substrate are shaped to follow the outer form of the Battery AND the inner form of the Housing, thereby utilizing the available space in the Housing (the Folded substrate having a substantially polygonal form comprising 6 vertices, all but one connected by straight line edges, the last containing a curved shape following the outer form (here a part of a circle) of the Battery, cf. e.g.FIG.2a). The embodiment shown inFIG.1bis similar to that ofFIG.1abut differs in that the outer edges of the Folded substrate are ONLY adapted to the inner form of the Housing (the Folded substrate having a polygonal form comprising 6 vertices connected by straight line edges, cf. e.g.FIG.2d).

FIGS.2a-2eshow various embodiments of a foldable planar substrate and corresponding folded substrate for being used in embodiments of a portable electronic device.FIGS.2a-2eshow five examples (top to bottom,FIGS.2a-2e) of Formed planar substrates (shown to the left) having an outer outline, which when folded 180° along the Folding line (the central dash-dotted line, surrounded by two symmetrically located dashed lines indicating the Folding zone), lead to the Folded substrate (shown to the right). The Formed planar substrate comprises 1stand 2ndparts extending to respective sides of (here symmetrically around) the Folding line.

FIGS.3a-3cshow an embodiment of a folded substrate shaped to follow the fixed outer contour of a battery, substrate and battery being a part of a portable electronic device, e.g. a device as illustrated inFIG.1a(compare parts Folded substrate and Battery inFIG.1a).FIG.3ais a perspective view of the folded substrate F-SUB, where one of the edges is shaped as a part of a circle to fit the circular form of a battery cell BAT. Various SMD components COMP are mounted on the folded substrate and electrically interconnected by conductors on the surface of the substrate and/or in one or more intermediate layers of the substrate. The folded substrate comprises an extension E-SUB from one of the folded parts of the folded substrate. The extension E-SUB of the substrate comprises electrical conductors (CON-B+, CON-M) for connecting the components on the folded substrate to the (positive terminal + of the) battery BAT and to another component (here a microphone, not shown), respectively. The electrical connections (CON-B+, CON-M) of the extension E-SUB comprise soldering pads or electrically conducting tape allowing (e.g. reflow) soldering or direct gluing of the battery and the microphone, respectively, to the extension E-SUB of the folded substrate F-SUB. Apart from the curved edge of the folded substrate F-SUB (forming part of a circle) facing the battery, the three other edges (one being the folded edge) are linear.

FIGS.3band3cshow two different perspective views of the folded substrate F-SUB (without components for clarity) including the extension E-SUB and in particular illustrating the form of the extended substrate. As illustrated byFIGS.3band3cthe folded substrate F-SUB including the asymmetric extension of the substrate E-SUB from one of the folded substrate parts can be created from one sheet of a planar substrate by appropriate forming and cutting and subsequent folding along the dashed folding lines (FL of the core folded substrate, and FL1-FL6of the extension) indicated inFIG.3b. Alternatively, the extension of the substrate E-SUB can be separately provided and electrically connected (e.g. along folding line FL1) to the (core) folded substrate F-SUB by conventional electrical connection techniques.

FIGS.4a-4bshow exemplary embodiments of a planar substrate comprising a (reduced thickness) folding zone.FIGS.4a-4bshow a part of a planar substrate P-SUB around a folding zone F-ZONE, which has been reduced in thickness to a folded zone thickness Ts,foldrelative to a (possibly average) thickness Tsof the planar substrate outside the folding zone F-ZONE. The planar substrate P-SUB is a multilayer substrate comprising a number of layers (here three intermediate layers are shown) for establishing electrical connections between components on the respective substrate parts (to the left and right sides of the folding zone F-ZONE) and for establishing electrical contact between the two substrate parts (including for creating electrical contact between components located on different substrate parts) via the folding zone F-ZONE. In the embodiment of a planar substrate shown inFIGS.4a-4b, five layers may be used for routing of electrical conductors (two on the opposite surfaces and three intermediate layers), the conducting layers (or rather the layers that may be used for routing of electrical conductors) being separated by electrically insulating layers. However, to decrease the critical folding radius, the substrate has been thinned in the folding zone F-ZONE by only continuing the centrally located, middle metal layer CC over the folding zone (possibly including (as shown here) surrounding insulating layers), whereas the top and bottom intermediate (conductive) layers TC and BC, respectively, are discontinued at the folding zone. The surface layers are preferably not used for routing or contacting in the folding zone F-ZONE. In the embodiment shown inFIG.4a, the transitions from the folding zone to the rest of the substrate having a ‘normal’ thickness are abrupt (step-formed), whereas they are made gradual in the embodiment ofFIG.4b. Further, the embodiment ofFIG.4bcomprises via holes VIA connecting two or more of the metal layers (here the three intermediate layers are connected) in a zone close to the folding zone to mechanically stabilize the parts of the substrate neighbouring the folding zone F-ZONE. In an embodiment, the substrate comprises a PCB, e.g. a flexible printed circuit board. Such so-called ‘flexprints’ (comprising customized footprints) are available from a number of vendors, e.g. Mekoprint Electronics A/S (of Denmark) or GS Swiss PCB AG (of Switzerland).

FIGS.5a-5bshow an embodiment of a portable electronic device, here in the form of a completely in the ear canal type hearing instrument.FIG.5ashows a cross-sectional view of the hearing instrument5when located fully in an ear canal of a user. The hearing instrument5is a self-contained instrument comprising microphone (M), battery (BAT) signal processing unit (SPU) and receiver (speaker, SP) (and possibly other relevant functional parts for providing appropriate amplification (or attenuation) of an input sound and presenting it as a processed output sound to the residual volume72close to the ear drum71according to a user's needs. The embodiment shown inFIGS.5a-5bis adapted for being located at least partially in the bony part74of the ear canal7. The ear canal7can have different lengths (and form) on different people as indicated by the double arcs76. The outer ear (pinna) is indicated with reference numeral75. A first part of the hearing instrument5having a relatively small cross section is located at least partially in the bony part74of the ear canal7. A second part of the hearing instrument5having a relatively large cross section is located at least partially in the softer part73of the ear canal7. The first part comprises a receiver (speaker) unit SP. The second part comprises the more voluminous components, such as e.g. a battery, a signal processing unit, a microphone system, and possible transceiver circuitry (e.g. for establishing a wireless link to another device, e.g. a corresponding hearing instrument at the opposite ear). A front end1of the first (slim) part of the hearing instrument comprises a wax filter2and an ear canal locating part15, here a dome part, comprising one or more structural elements for adapting its/their form to the ear canal and thereby controlling the position of the instrument (incl. the receiver) in a cross section of the ear canal. The embodiment of the hearing instrument shown inFIGS.5a-5bcomprises two vent channels30,30′ running along a periphery (in a longitudinal direction) of the housing51of the instrument comprising the electronic components (e.g. battery BAT, receiver SP, microphone and folded substrate F-SUB comprising signal processing unit SPU and interconnection circuitry). The folded substrate comprising the (typically mainly digital) signal processing unit SPU and a (typically mixed analogue and digital) front end chip FE is shaped to follow the outer surface of the battery BAT and of an inner surface of the housing51. The hearing instrument may have any other convenient form, and be located elsewhere in the ear canal (e.g. outside the bony part). Likewise a vent of the hearing instrument may be located elsewhere (e.g. internally) and may be present in other numbers than two (or omitted altogether). The folded substrate F-SUB comprises a folding zone FZ extending around the folding line, where no components are mounted (as indicated by the dotted line inFIG.5aand the vertically hatched area of the folded substrate inFIG.5b). The folding line of the substrate is indicated by dashed arrow FL. InFIG.5b, the listening device shown inFIG.5ais enlarged to better illustrate the features of the folded substrate as described above. The electrical connections (‘footprint’ FP) between the components of the folded substrate are schematically indicated inFIGS.5a-5b. Connecting points CP are shown as pads electrically connected to contact points on components external to the folded substrate (here a battery BAT, a speaker SP and a microphone M are shown) by connecting wires CW.

FIGS.6a-6bshow two perpendicular views of an embodiment of a folded substrate according to the present disclosure.FIG.6ashows a cross-sectional side view (taken along line AA′ inFIG.6b) of a 180° folded substrate comprising a first part F-SUB-1P and a second part F-SUB-2P separated by the folding line FL, each part being equipped with electronic components COMP1-COMP4mounted on both sides of the respective planar substrate parts. A folding zone FZ comprising the curved parts of the first and second substrate parts is (symmetrically) located around the folding line FL. A folding radius Rfoldadapted to be larger than a critical folding radius of the substrate is indicated (as an ‘inner’ radius; it may alternatively be taken as the folding radius of a centrally located, median plane of the substrate) together with an (inner) distance TIFSbetween opposing surfaces of the first and second substrate parts. Here the thickness (TIFS) of the folded substrate (without mounted components) is equal to twice the folding radius (Rfold). The folding zone FZ is, on the other hand, larger than IT times the folding radius (Rfold) (in a direction perpendicular to the folding line FL, when measured in an un-folded view of the planar substrate, the folding line FL running perpendicular to the view ofFIG.6a). The folded substrate further comprises a component DIST adapted for ensuring a minimum distance (TIFS) between the opposing surfaces of the folded substrate. In an embodiment, the component DIST comprises a locking mechanism for locking the two ends of the finalized folded substrate, which eases handling during manufacturing of the device. In an embodiment, a number of such components adapted for ensuring a minimum distance between the opposing surfaces of the folded substrate are distributed on the folded substrate, e.g. located in parts of the substrate where no other components are easily mounted (e.g. in a wedge formed part of the substrate).FIG.6bshows a top view of the first part F-SUB-1P of the folded substrate ofFIG.6a. The upper side of the first part F-SUB-1P of the folded substrate (folded along folding line FL) comprises component COMP1, e.g. a digital signal processor (e.g. SPU ofFIGS.5a-5b). The folding zone FZ of the first part F-SUB-1P of the folded substrate is indicated in vertical hatching. The right (non-folded) edge SE of the folded substrate is shaped to fit a circular component, e.g. a battery. Thereby thin, wedge-formed areas of substrate part(s) are created. The component COMP1is electrically connected (by conductors CC1, CC2) to contact points CP located in the wedge-formed areas (e.g. for making electrical contact to an external component, e.g. a battery), thereby utilizing the available (otherwise un-useable) area better. The component COMP1is connected to other components on the folded substrate located on the second part F-SUB-2P via connecting conductors CC3, CC4routed over the folding zone FZ. Conductors CC3, CC4may run in an intermediate layer of the substrate (e.g. in wiring of a central, conductive layer CC inFIGS.4a-4b) or (as shown here) on the (upper) surface of the substrate.

The component COMP1may be connected to components on the opposite side of the first part of the folded substrate (e.g. COMP2, cf.FIG.6a) by means of vias in the substrate electrically connecting the two surfaces of the first part of the folded substrate F-SUB-1P. Apart from the shaped edge SE, the other edges of the folded substrate are linear and form a rectangular outline.

The invention is defined by the features of the independent claim(s). Preferred embodiments are defined in the dependent claims. Any reference numerals in the claims are intended to be non-limiting for their scope.

Some preferred embodiments have been shown in the foregoing, but it should be stressed that the invention is not limited to these, but may be embodied in other ways within the subject-matter defined in the following claims.

REFERENCES

US 2008/0137891 A1 (Vohringer) Dec. 6, 2008U.S. Pat. No. 6,208,741 (INSONUS MEDICAL) 27 Mar. 2001WO 00/25551 A1 (BELTONE ELECTRONICS) Apr. 5, 2000U.S. Pat. No. 6,751,327 (INSONUS MEDICAL) 15 Jun. 2004