WO2009019031A1

WO2009019031A1 - Improvements in or relating to electronic apparatus and associated methods

Info

Publication number: WO2009019031A1
Application number: PCT/EP2008/006541
Authority: WO
Inventors: Pekka Markus Kilpi; Harri Aukusti Lasarov; Petri Ounila; Ari-Pekka Töykkälä
Original assignee: Nokia Corporation
Priority date: 2007-08-09
Filing date: 2008-08-07
Publication date: 2009-02-12
Also published as: GB0715544D0; GB2451676A; GB2451676B

Abstract

An electronic apparatus comprising a protective housing, wherein the protective housing is formed from a thermoset resin and is substantially integrated with some or all of the electronic components adjacent said protective housing. The electronic apparatus may have a user interface and/or be a power cell for an electronic device.

Description

Improvements in or relating to electronic apparatus and associated methods

Technical Field

The present invention relates to the field of electronic apparatus having electronic circuitry/components which is/are protected by a protective housing, and associated methods of manufacture.

Such apparatus includes, but is not limited to, electronic apparatus comprising a user interface, the user interface allowing the user to input and/or receive output data, via the generation of associated signalling using the user interface. Such apparatus may be hand-portable (or so-called "mobile"), and include devices providing one or more of mobile (e.g. video/audio calling/messaging) communication functionality, mobile organising functionality (e.g. electronic diaries), and/or mobile entertainment functionality (e.g. audio/video recorders/players and/or gaming devices). The entertainment provided may be received over an air interface (e.g. a video signal received at an antenna of apparatus) and/or be provided by memory circuitry which is physically connected to the apparatus (e.g. a removable memory card/disk etc.).

Electronic apparatus which are within the scope of the present invention and which may not necessarily comprise a user interface are, for example, portable power cells (e.g. battery) which are for use with mobile electronic apparatus, particularly mobile electronic apparatus with a user interface.

For the sake of convenience, the following discussion will be primarily focussed on radio telecommunication devices, such as mobile phones. However, it will be appreciated that the present invention is not limited to radio telecommunication devices or mobile phones.

Background Presently, devices such as mobile phones are constructed from A/B/C mechanical covers, displays, batteries, printed wiring boards (PWBs) etc, which are put together in a final assembly phase (i.e. "post assembly") in which they are fixed together with screws, tapes, hooks etc. Hence, the mechanics are usually a completely separate layer on top of the functional electronics/circuitry.

Naturally, as a result of this manufacturing process, there will be air gaps and clearances between the electronic components, as well as between the components and mechanics covers. Such air gaps may detrimentally allow the ingress of liquids. Furthermore, in the case of particularly thin devices, the mechanical strength for such "post-assembled" structures will be comparatively weak compared to thicker devices. In addition, the assembly of increasingly small/thin devices will lead to increasingly difficult assembly of such devices.

Thermoset casting of protective housings is a known process. This process provides a liquid state plastic material (a thermoset resin) into a (e.g. metal) mould which then sets to provide the protective housing. In certain embodiments, the liquid state material may be injected under pressure. The final material properties can be achieved after curing by using heat (as with a one-component system), or by using catalyst (as with a two-component system). In the case of the two- component systems, in particular, the thermoset resin can be cast at room temperature, without the use of injection under pressure.

It should be noted that in traditional injection molding processes, the injection pressure is typically 1000-1500 bar and the melt temperature during the injection phase may be from 200⁰C up to 35O⁰C. Accordingly, the use of these processed for sensitive electronic components has been limited. Namely, the use of the thermoset casting process has been mainly limited to simple "dummy" charger Printed Wiring Boards (PWBs) or other plugs. Such chargers/plugs provide a single functional mode of operation i.e. they act as a charger/plug. The process has not been applied to complicated electronic devices which are capable of performing a plurality of functions (e.g. messaging, audio playing, calendar functions etc.) i.e. those with a plurality of functional modes.

Macromelt moulding, or "low pressure adhesive moulding" is also a known technology which uses a thermoplastic material based on reformulated hot melt adhesives to provide a protective cover for electronic components. As mentioned above, the thermoset casting is a known process typically employed for providing a protective cover of a plug/charger. Both thermoset casting and macromelt moulding are not known to be used in the manufacture of mobile devices with user interfaces or portable power cells.

There are basically two casting technologies:

(i) potting - liquid potting material is poured into an open mould or cup; this cup remains part of the structure after the potting material has cured.

(ii) RIM (Reaction Injection Moulding) - liquid material is injected into closed mould, and the part is removed from the mould after curing.

Due to the high pressure and temperature of the second process, RIM cannot be used as such in over-moulding when used with sensitive electronic components. Also, post-assembling separate plastic parts with electronic devices produces not only thicker devices, but also mechanically weaker and (relatively) loosely layered structures in comparison to thermoset cast hybrid parts.

Thermoset casting is a better solution, as such casting is done in a liquid state as a low pressure and low temperature process. However, this also means that the necessary casting mould or filling jigs need to be very tight in order to prevent the liquid potting/casting materials from leaking. When moulding larger plastic parts, the viscosity of the potting material can be increased to eliminate leakage, while in miniaturized structures (e.g. mobile phones), the material must have a very low viscosity so that it flows to fill all small gaps and even under components. This can also pose difficulties when constructing miniaturized structures, as if the moulding material is of a low viscosity it can often leak undesirably into electronic components and cause malfunction or failure of said components.

Due to the sensitivity of typical embedded electronics, only a certain amount of pressure can be applied to the mould.

Also, as most parts are mass manufactured and hence distances between the parts always have some dimensional variation that needs to be addressed in some way.

Thermoset materials (e.g. thermoset PUR) or epoxy materials are very adhesive. This causes sticking problems to jigs and moulds. In most cases silicone or other release agents cannot be used to eliminate jig/mould deposit problems.

Furthermore, none of these methods explicitly provide a method through which it is possible to selectively mould areas of an electronic apparatus, or to include some spaces inside the structure / substructure that are completely free of thermoset plastics. One or more aspects/embodiments of the present invention may or may not address one or more of the background issues.

The listing or discussion of a prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge.

Summary

In a first aspect, there is provided a portable electronic apparatus comprising a protective housing, wherein the protective housing is formed from a thermoset resin and is substantially integrated with some or all of the electronic components adjacent said protective housing. The apparatus may comprise electronic components arranged to allow the apparatus to be used to provide a plurality of functional modes. These functional modes may include one or more of a mobile communication functionality mode, mobile organising functionality mode, and/or mobile entertainment functionality mode or sub-aspects of such modes.

The protective housing may form the exterior housing of the apparatus. A further housing may be removably/permanently attachable to the protective housing, and the protective housing may be appropriately adapted to receive this further housing.

The apparatus may comprise one or more other protective housings formed from a non-thermoset resin. Thus, the protective housing for the apparatus need not necessarily be exclusively made from thermoset resins, but may be combined with other non-thermoset resin protective housings to provide some regions of the apparatus which are protected by a thermoset resin protective housing and other regions which are protected by non-thermoset protective housings.

The apparatus may comprise a non-thermoset material forming part of the thermoset protective housing. For example, the apparatus may comprise a non- thermoset material forming part of the thermoset protective housing by the non- thermoset material being attached to the thermoset protective housing while the thermoset protective housing is setting from the thermoset resin.

The apparatus may comprise a non-thermoset material forming part of the thermoset protective housing by the non-thermoset material being attached to the thermoset protective housing while the thermoset protective housing is setting from the thermoset resin by using the adhesive properties of the setting thermoset resin.

The non-thermoset material may be attached once the thermoset resin has substantially set, or the liquid thermoset resin may be applied over an appropriately positioned non-thermoset material provided in the mould which is used to form the protective housing.

The non-thermoset material may include one or more of natural materials (such as wood, wool, silk, cotton, leather/suede), metal, fabric (including cotton, silk, leather/suede), high temperature sensitive materials (e.g. veneered wood, artificial/natural cloth/fabric, plastic), and/or plastic.

The non-thermoset material may be a thin sheet which may comprise one or more graphical designs e.g. an aluminium foil, carbon fibre sheet, paper sheet.

The thermoset resin may be adapted to comprise additives/fillers to enhance the thermal conductive properties of the set thermoset resin. The following three general classes of fillers can be used to increase the thermal conductivity of thermoset plastic: Carbon fillers e.g. carbon fibres and carbon powder; Metallic fillers e.g. copper powder, steel, aluminium powder and aluminium flake; Ceramic fillers e.g. boron nitride, aluminium nitride and aluminium oxide.

The apparatus may be arranged such that the thermoset protective housing defines an apparatus region suitable for the releasable attachment of a power cell.

Some, a substantial proportion, or all the electronic components of the apparatus may be formed on one or more mechanical frame(s) (chassis), and the thermoset resin may be applied to (or around) the mechanical frame(s) and the electronic components to form an integrated protective housing for the electronic components.

The electronic components may be formed on the mechanical frame such that the electronic components are electrically and mechanically fixed to provide an operational apparatus prior to the application of the thermoset resin.

The mechanical frame may comprise a printed wiring board of the apparatus itself. The mechanical frame may comprise a mechanical frame which is not a printed wiring board of the apparatus but to which one or more printed wiring boards of the apparatus are attached.

The mechanical frame may be made from a continuous structure (e.g. sheet of material) to which are attached, in a plurality of respective areas, components for respective electronic apparatus, and one particular apparatus may be formed by separating (e.g. cutting) a particular respective area from one or more other areas.

The separation may be performed after the thermoset resin has been applied to substantially set over a plurality of regions of the continuous structure. Alternatively, the respective areas may be separated from the continuous structure prior to the application of the thermoset resin.

The mechanical frame may comprise one or more (e.g. mechanical) stand-offs to define a clearance between one or more respective walls of the mould, used to form the protective housing from the thermoset resin, and one or more respective electronic components.

One or more of the stand-offs may remain hidden or visible in the finished electronic apparatus.

One or more components may be protectively covered (e.g. by a protective sheet) prior to the application of the thermoset resin to protect the component(s) from the thermoset resin.

One or more components may be protectively covered by a cover (e.g. sheet) which is removable after the thermoset resin has substantially set. Such components may include user interface elements selected from the group comprising an electronic display, keypad/touchpad, and/or camera lens.

An electronic apparatus according to claim 1 , wherein apertures are defined in the thermoset protective cover by the use of one or more removable plugs (e.g. made of rubber/elastomer material) positioned to create a region into which the thermoset resin does not flow during the setting of the resin.

The apertures may be arranged to allow for electrical connection of a peripheral device, such as an audio plug (e.g. from a headset), memory card (e.g. SIM/USB).

The mechanical frame may comprise one or more apertures which define corresponding one or more apertures for use in the electrical connection of one or more peripheral devices, the apertures arranged such that the thermoset resin is not able to flow into said apertures during the formation of the protective cover.

The apertures may be arranged to extend perpendicularly/parallel to the direction of insertion of the thermoset resin. The apertures may be arranged to lie in a horizontal plane when the protective housing is formed. The apertures may be arranged such that the apertures which are formed extend in a plane parallel to a front face of the apparatus in use (e.g. apertures are formed on the side of the main front face of the apparatus).

The apparatus may comprise one or more defined heat conductive paths which extend through the thermoset protective housing from one or more electronic components (e.g. which generate significant heat when in use) towards the outer surface of the protective cover.

The defined heat conductive paths may terminate at the outer surface or proximal to the outer surface of the protective cover. The heat conductive paths may be formed to extend from the mechanical frame, or be provided by heat conductive paths defined by the frame itself. The defined heat conductive paths may be provided by appropriately positioned graphite foils, which may be formed to extend from the mechanical frame.

The apparatus may comprise a mechanism to provide the apparatus with a number of mechanical configurations. The apparatus may comprise a mechanism to provide the apparatus with a number of mechanical configurations, the mechanism comprising one or more cover(s) arranged to inhibit the ingress of thermoset resin during the setting process which would otherwise prevent the mechanism from providing the number of mechnical configurations. The mechanism may provide slid/tilted/rotated configurations of the apparatus.

The electronic components of the apparatus may be substantially embedded within the thermoset resin.

The electronic apparatus may be a (e.g. rechargeable) power cell for an electronic device. The electronic device may be arranged to be able to provide a plurality of functional modes of the device.

Substantially the whole of the apparatus housing may be formed from a thermoset resin.

In a second aspect, there is provided a front or rear face protective housing (e.g. so-called A, B, C covers for mobile phones) for a portable electronic apparatus, the housing being formed from a thermoset resin and (e.g. user-releasably without tools) attachable to another housing to provide a protective cover for the apparatus. Both the front and rear face protective housings may be formed from a thermoset resin. They may be arranged to be user releasably connected to one another.

The front/rear protective housing may be for an electronic apparatus comprising a user interface.

In a third aspect, there is provided a portable rechargeable power cell, wherein the rechargeable power cell comprises a protective housing integrated with the exterior of the power cell, the protective housing being formed from a thermoset resin. In a fourth aspect, there is provided a method of forming a portable electronic apparatus, the apparatus comprising a protective housing and electronic components protected by said protective housing, wherein the protective housing is formed by applying a thermoset resin to some or substantially all of the electronic components of the apparatus to substantially integrate some or substantially all the electronic components adjacent the set protective housing with the set protective housing.

The fourth aspect may comprise the steps of: defining an open potting cavity using a gasket member positioned on said apparatus to encircle said electronic components but to leave a filling aperture, the open potting cavity further defined by a film positioned over the gasket member opposing the apparatus, the gasket member forming a liquid proof joint with the apparatus and the film; filling the potting cavity with liquid potting material and curing the potting material.

The gasket member may be any regular or irregular shape so as to define a desired potting cavity shape.

The gasket member may be formed of any suitable material, such as an elastic material or a poron material.

Any of the aforementioned apparatus may be a circuit board (i.e. a printed wiring board/circuit board).

The present invention includes one or more aspects, embodiments or features in isolation or in various combinations whether or not specifically stated (including claimed) in that combination or in isolation. Corresponding means for performing one or more of the discussed functions are also within the present disclosure.

The above summary is intended to be merely exemplary and non-limiting. Brief Description of the Figures

A description is now given, by way of example only, with reference to the accompanying drawings, in which:-

Figure 1 is a cross section view of a mobile phone PWB and associated electronic circuitry used in one embodiment of the present invention;

Figure 2 is a cross section view of a mobile phone PWB and associated electronic circuitry used in another embodiment of the present invention;

Figure 3 shows a close up view of the embodiment of Figure 1 with a protective sheet for a display applied to the display;

Figure 4 is an embodiment of a mobile phone according to another embodiment of the present invention; Figure 5 is shows a continuous frame supporting multiple assemblies for apparatus of the present invention; and

Figure 6 shows an electronic apparatus made from a plurality of layers according to the present invention.

Figure 7 shows a side-on view of apparatus used in a method of forming a selective area of protective housing.

Figure 8 shows a top-down view of apparatus used in a method of forming a selective area of protective housing.

Figure 9 shows a view of the apparatus in Figures 7 & 8 in a support jig.

Figure 10 shows the flowchart of the method shown in Figures 7-9. Figure 11 shows tear-away portions useable in another embodiment of the invention.

Figure 12 shows an actual example of the method of Figures 7-9.

Figure 13 shows the removal of protective film as provided in the method of

Figures 7-9.

Description of Specific Embodiments Embodiments of the present invention can use a variety of thermoset casting processes including potting/open mould casting, in which a liquid resin is poured into an open mould or cup/pot, and reaction injection moulding (RIM), in which a closed mould is injected with a thermoset resin. Examples of thermoset resins which can be used in or more embodiments of the invention include epoxy, silicone and polyurethane.

However, the temperature/pressure of the moulding process is controlled so as not to damage the sensitive electronic components of the electronic apparatus of the present invention. The process control parameters will depend on the electronic apparatus being manufactured. For example, the temperatures may be of the order of 200⁰C or less, and in the case of an apparatus with an electronic display, the temperature may be controlled to be not above 50°-60°C.

Potting/open mould casting are low pressure/temperature processes which use a low viscosity thermoset resin (one with low shear stresses). In open mould casting/potting, the molded part (i.e. the formed part) is usually not removed from the mould after curing because the mould becomes typically part of the cast product. RIM is similar to plastic injection molding and uses also a low pressure/temperature process and a low shear thermoset resin. In the case of RIM, the cured part is removed from the mold.

The thermoset resin may be formed into a liquid state by heating the resin from a viscous state. The thermoset resin may be formed by mixing together two components (e.g. Polyol and Isocyanate). The thermoset resin may be an "elastic" thermoset which can be subjected to a degree of deformation without it breaking (e.g. some degree of flexibility).

Let us now consider the use of a thermoset casting process to manufacture a mobile phone, taking the cross sectional diagram of Figures 1 - 4 as examples. The figures show electronic assemblies 100, 200 around which is cast a thermoset resin to provide a protective coating for the phone (Figures 3 and 4). In the case of Figure 1, the printed wiring board 10 of the phone acts as a chassis to which the other electronic components 20-70 are attached such that they are both mechanically and electrically connected together before the thermoset casting process. The respective components may be connected to the chassis with for example, double-sided tape, hooks or screws. The chassis may also have features which locate and/or even fix the electronic components to itself. Soldering or some other form of mechanical attachment can be used to attach the electronic components to the chassis.

In the case of Figure 1, a display 20 and user input interface 30 are provided on the front facing face of the PWB 10 and a battery 40, radio communication engine components 50, and antenna 60 are provided on the rear face of the PWB 10. In addition, a connector 70, for allowing connection of the phone to a peripheral device (e.g. USB headset, audio jack, memory card etc.) is also provided on the rear bottom end of the PWB 10. The connector 70 aperture/connection face is accessed via a side face of the phone. It will be appreciated that the respective electronic components should be connected together in a grounded state.

The assembled chassis is placed in a mould (not shown) into which a thermoset resin is provided. The mould defines the overall shape of the mobile phone. Due to the liquid nature of the resin, the resin spreads over and inbetween the respective electronic components 10, 20, 30, 40, 50, 60 to integrate them with the resin once the resin is set (sufficiently hardened). The extent to which the electronic components are integrated with the formed protective housing 80 depends on a number of factors including the viscosity of the resin, the temperature of the forming process etc. In some embodiments, the respective components 10-70 may be fully integrated with the resin such that there are no gaps between the respective components and the adjacent set resin. In other embodiments, only some of the electronic components adjacent the formed protective housing 80 are partially integrated with the formed protective housing 80.

With a sufficiently small tolerance, the mould can be manufactured such that the thickness of the set resin (and thus the protective housing 80 formed) above the components 10-70 is of the order of a couple of tenths of millimetres (O.Xmm). This can be considered to be of the order of the air gaps between current the electronic components of current mobile phones and their associated casings. Advantageously, screws and clip arrangements are not required to provide the phone with a protective housing.

In another embodiment (Figure 2), the PWB 10 does not form the chassis, but a separate mechanical chassis/frame/structure 11 provides the support for the electronic components 10-70. In Figure 2, the position of the connector 70 is not at the bottom end but towards a more central position. However, the connector aperture/connection face is still accessed from a side face of the phone.

In the case of Figure 2, the PWB is smaller than the PWB of Figure 1, and thus the mechanical frame 11 is advantageously used to fix components, including the PWB 10, together. The frame 11 may be made from plastic and/or metal which may be bent, cut or die cast etc.

Post processing may be performed after the thermoset resin has set. This may include curing to facilitate setting of the resin or machining surfaces to provide a neat finish. For example, any part of the frame 10, 11 which extends out of the thermoset resin may be cut off to provide a smooth finish. The formed protective housing may also be painted or metallized. A thin film comprising graphic/colouring etc. may also be applied to an outer face of the formed protective housing.

In certain embodiments, the mechanical frame 11 and/or the PWB 10 may define apertures into which the applied resin does not flow. These apertures may be positioned for the insertion/connection of a peripheral device such that the peripheral device can be subsequently used with the phone.

To prevent the front face of the display 20 from flow of the liquid resin, a removable sheet 21 (Figure 3) may be provided to cover the display 20 during the thermoset casting process. This sheet 21, which would advantageously be a thick soft material, is then removed once the resin is sufficiently set. The thickness of the material would be such that it is thicker than the protective housing 80 which is formed by the thermoset resin. A sheet 21 can be used to protect any other (particularly sensitive) electronic components which would remain visible in the final product.

In certain embodiments, appropriately positioned removable rubber/elastomer plugs may be used to protect apertures from the ingress of the liquid thermoset resin (for example, in the case of a microphone/earpiece port). An elastic peel-off sheet (e.g. 21) can also be used to protect apertures from the ingress of liquid resin and/or protect a keymat (or camera lens).

In certain embodiments, the mould into which the assemblies 100, 200 are placed are provided with some form of stand-off to hold assemblies 100, 200 away from the walls of the mould. This would allow the resin to pass between the outer face of the electronic components and the mould walls to define cavities into which the resin may flow prior to setting. In other embodiments, the stand-offs 90 may be part of the assemblies (e.g. Figures 4, shown for the embodiment of Figure 1, and a corresponding embodiment for the embodiment of Figure 2 is not shown but is within the present disclosure).

The stand-offs may be made from any suitable material (e.g. plastic, metal). In some embodiments, they may be chosen such that they dissolve/melt away towards the latter part of the setting process so that they provide the required stand-off function while the thermoset resin is very liquid, but dissolve/melt away as the resin gets to the latter stages of setting.

In the embodiments of Figures 1 and 2, all the electronic components 10-70 are permanently assembled into the phone once the resin is set. However, in other embodiments, one or more components may not be permanently set but apertures provided for the subsequent non-permanent connection of the electronic apparatus. For example, the battery 40 may not be part of the assembly, but an aperture may be provided for the subsequent releasable connection of a battery 40. In one embodiment, rather than provide a thermoset resin covering both the front and the back the phone 100, 200 at the same time, the thermoset process can be used to make just one of the front/back covers formed with integrated electronic components. For example, the A cover could be formed with integrated electronic components with features (e.g. apertures/hooks/mating face etc.) to which that the B/C covers may be subsequently (permanently/releasably) attached. These B/C covers may be manufactured using a thermoset casting process of the present invention or be manufactured in some other way.

In another embodiment still, rather than manufacturing individual discrete assemblies for each respect apparatus on corresponding separate chassis/frames, a continuous frame could be assembled with respective assemblies positioned in discrete locations each for a particular apparatus (Figure 5). Thus, many apparatus can be cast together in the same thermoset casting process, and then subsequently separated by cutting (see dashed line in Figure 5), the respective apparatus formed at the various discrete locations.

If the resin has sufficient adhesive properties in the "setting state" (i.e. when not fully set), then non-thermoset materials (e.g. natural materials (wood, wood veneer, leather, fabric) and non-natural materials (e.g. cast/extruded/machined metal, fabric)) can be applied to the setting resin. In this way, a different finish can be applied to the surface of the formed protective housing 80 i.e. a partial/complete leather/fabric/wooden outer cover for a portable electronic apparatus (e.g. mobile phone).

In certain embodiments, the non-thermoset material can be appropriately placed in the mould with the assembly 100, 200 prior to addition of the thermoset resin. In other embodiments, the non-thermoset material can be added to the partially set thermoset resin towards the latter stages of the setting process after it has been removed from the mould. The adhesion between the thermosetting resin and the non-thermoset material may be supplemented by the use of an adhesive. In another embodiment still, rather than using the adhesive properties of the setting thermoset resin, the non-thermoset material can be applied to the surface of the formed protective housing with an adhesive.

In certain embodiments, buttons may be added to the thermoset resin protective housing once it has set. For example, part/all of the keymat area of the phone may be protected from ingress of liquid resin to protect the areas to which buttons are to be attached. Then, buttons may be attached (e.g. using co-operative locking elements such as hooks) to these protected areas during the latter stages of the resin setting process. However, in other embodiments, these buttons may be pre- assembled on the assembly 100, 200 and protected from the ingress of liquid resin.

Thermally conductive components (heatpipes)/sheets (e.g. graphite foil) can be applied to the assembly 100, 200 to act to conduct generated heat away. These components/sheets may become (e.g. fully) embedded within the protective housing to efficiently act as heat conductors.

Figure 6 shows the sub-assembly of a thermoset cast electronics and battery assembly 100 for a particular portable electronic apparatus 800. A connector 110 is provided to connect the hermetically sealed caste electronic components of the assembly 100 to other components of the apparatus (e.g. to the display 400 and/or an adjacent connection module 150 which comprises USB ports 115 to allow for connection to another device - it will be appreciated that, in other embodiments, the connection ports could be integrated with the cast assembly 100).

This assembly 100 is encased by respective inner metal case covers 600 on the outer surface of one of which is provided a display electronics 400. The covers 600 define apertures 610 through which the connection ports (e.g. USB ports) allow for connection. Although the assembly 100 comprises some display electronic components, other components of the display (e.g. the pixel forming areas, touch sensitive areas) are provided outside the protective metal casing 600. Other layers are applied, including a layer 500 for capacitive touch sensing, a protective sheet window 600 and a top frame 700 applied to form a decorative/strengthening perimeter frame around the formed apparatus 800.

It will be appreciated that the mould used in the thermosetting process may be formed from two or more mating parts, or be a single mould. The mould may also not be removable from the apparatus once the resin has set, and itself form part of the protective housing of the apparatus. It will also be appreciated that the aforementioned circuitry/electronic components may have other functions in addition to the mentioned functions, and that these functions may be performed by the same circuit/components.

Figures 7-9 illustrate a further method of assembling the apparatus with said protective housing. Figure 10 illustrates the steps of this method. Figure 12 clearly shows an example of this method in practice. In these embodiments, the apparatus 702 may be a circuit board/printed wiring board upon which electronic components 703 are connected.

As in previously discussed embodiments, the apparatus 702 comprises electronic components 703, some of which (if not all) are to be integrated with the protective housing. The protective housing is intended to act as a reinforcement layer of the finished apparatus 702. In order to form the protective housing, a mould is provided in the form of a potting cavity 704. The potting cavity 704 comprises a U-shaped elastic gasket member 708 and a protective film 706 formed from a suitable material, e.g. thin film of PET. In this preferred embodiment the gasket member 708 is U-shaped, however it could of course be any other regular or irregular shape in order to define a desired shape of potting cavity 704.

The potting cavity 704 is arranged on the apparatus such that the electronic components to be integrated with the protective housing are located in the potting cavity 704 (step 801) by arranging the gasket member 708 to encircle said electronic components 703. The protective film 706 is positioned over the gasket member 708, the apparatus 702 and the protective film 706 thereby defining opposing walls/sides of the potting cavity 704. The gasket member 708 defines the perimeter of the potting cavity 704 and defines the bottom wall and two sidewalls of the cavity 704. The gasket member 708 is arranged to provide a liquid proof seal when in contact with the protective film 706 and the apparatus 702.

The top of the U-shaped gasket member 708 is open, leaving a filling aperture to allow filling of the potting cavity 704 with liquid potting material (e.g. thermosetting material, epoxy, etc; see Fig. 12). The liquid proof seal prevents the potting material from leaking out of the potting cavity 704 onto or into electronic components outside of the potting cavity 704 during the filling step (step 802).

The apparatus 702 and the potting cavity 704 are held (e.g. sandwiched or supported) between first and second support members 710, 712. The first and second support members 710, 712 define a support jig 713 for supporting the apparatus 702 and potting cavity 704 during the filling of the cavity with liquid potting material, and during curing of the potting material (curing step 803). The pressing together of the first and second members helps to tighten the structure and eliminates leaking of the potting material. The U-shape gasket member of the present embodiment makes it possible to fill the cavity from the top of the potting cavity 704 and to fill curved and odd-shaped parts easily.

Conventional support jigs typically provide the mould for forming comparable protective housing, and therefore need to be made from select non-stick materials such as Teflon or silicon in order to effect release of the apparatus to be assembled. This can also only be done once the material has at least dried and/or cured. In contrast, in this method the potting cavity 704 defines the mould for the protective housing to be formed rather than the support jig 713. The gasket member 708 and, more specifically, the film 706 prevent the potting material from coming into contact with the support jig 713 during filling. Therefore, the apparatus 702 and potting cavity 704 need not be supported in said support jig 713 throughout both of the filling and curing steps, as a (moulding) jig is not required to effect correct moulding. Furthermore, as the jig 713 does not come into contact with the potting material, the support jig 713 can be made from many other materials that are considered unsuitable for conventional support jigs/moulds, i.e. materials that are not nonstick or naturally lubricated. A further advantage provided by this moulding arrangement is that the potting cavity 704 (as defined by the gasket member 708 and protective film 706) eliminates the need for conventional moulds provided by two halves; hence sealing problems typically associated with using such mould halves are avoided.

Potting material is poured in through the open top of the potting cavity 704. Once the cavity 704 is filled or filled to a desired level the pouring is stopped. The potting material is then allowed to be cured (step 803). The potting material 704 may be thermoset material that can be formed from one, two, three or even more parts, i.e. it may be a thermoset material based on epoxy, silicone or urethane chemistry or a combination of these. The properties of the material may also be tailored to desired specifications, e.g. low/high viscosity, quick/slow drying etc, in order for the potting material to be suitable for use with a given potting cavity (see background). For example, when embedding/integrating sensitive components with the protective housing, (e.g. display, light guide, capacitive foils, PWB- components, battery etc) it is preferable to use a two-component system so as to decrease the required curing temperature.

The gasket member 708 and the protective film 706 are arranged to adhere to the potting material whilst it is curing. The protective film 706 may be used as a decorative area or as an area providing information, e.g. regarding the apparatus/circuit board 702. Alternatively, either or both may be at least partly removable after curing (see Fig. 13). In another embodiment (see Fig. 1 1), tearaway portions 709 may be provided for use with the gasket member 708 to keep areas that must not be filled with potting material free of said material. For example, this may be performed by folding the tearaway portions 709 round onto the gasket member 708 to provide a larger sealing area adjacent to the gasket member 708, and/or between the gasket member 708 and the protective film 706. These features help to afford additional protection against the potting material spilling into undesired regions, and/or provide additional mechanical support so as to further prevent the leaking of potting material onto or into electronic components outside the potting cavity 704 during filling of the cavity 704. These may then be torn away after the filling/curing steps.

In alternative embodiments, the gasket member may by provided by means of injection directly onto the apparatus so as to define the area of the potting cavity.

In the above described embodiments, the gasket member 708 is ideally formed from an elastic material. In another advantageous embodiment, the gasket member 708 and film 706 comprise conductive material in order to provide RF shielding for the integrated electronic components.

The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.

While there have been shown and described and pointed out fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices and methods described may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. Furthermore, in the claims means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.

Claims

1. A portable electronic apparatus comprising a protective housing, wherein the protective housing is formed from a thermoset resin and is substantially integrated with some or all of the electronic components adjacent said protective housing.

2. An electronic apparatus according to claim 1, wherein the apparatus comprises electronic components arranged to allow the apparatus to be used to provide a plurality of functional modes.

3. An electronic apparatus according to claim 1 or claim 2, wherein the apparatus comprises a non-thermoset material forming part of the thermoset protective housing.

4. An electronic apparatus according to any preceding claim, wherein the apparatus comprises a non-thermoset material forming part of the thermoset protective housing by the non-thermoset material being attached to the thermoset protective housing while the thermoset protective housing is setting from the thermoset resin.

5. An electronic apparatus according to any preceding claim, wherein the apparatus comprises a non-thermoset material forming part of the thermoset protective housing by the non-thermoset material being attached to the thermoset protective housing while the thermoset protective housing is setting from the thermoset resin by using the adhesive properties of the setting thermoset resin.

6. An electronic apparatus according to any of claims 3-5, wherein the non- thermoset material include one or more of natural materials, metal, fabric, high temperature sensitive materials, and/or plastic.

7. An electronic apparatus according to any of claims 3-6, wherein the non- thermoset material may be a thin sheet which may comprise one or more graphical designs e.g. an aluminium foil, carbon fibre sheet, paper sheet.

8. An electronic apparatus according to any preceding claim, wherein the thermoset resin comprises additives to enhance the thermal conductive properties of the set thermoset resin.

9. An electronic apparatus according to any preceding claim, wherein the thermoset protective housing defines an apparatus region suitable for the releasable attachment of a power cell.

10. An electronic apparatus according to any preceding claim, wherein some, a substantial proportion, or all the electronic components of the apparatus are formed on one or more mechanical frame(s), and the thermoset resin is applied to the mechanical frame(s) and the electronic components to form an integrated protective housing for the electronic components.

11. An electronic apparatus according to claim 10, wherein the electronic components are formed on the mechanical frame such that the electronic components are electrically and mechanically fixed to provide an operational apparatus prior to the application of the thermoset resin.

12. An electronic apparatus according to any of claims 10-11, wherein the mechanical frame comprises a printed wiring board of the apparatus itself.

13. An electronic apparatus according to any of claims 10-11, wherein the mechanical frame comprises a mechanical frame which is not a printed wiring board of the apparatus but to which one or more printed wiring boards of the apparatus are attached..

14. An electronic apparatus according to any of claims 10-13, wherein the mechanical frame is made from a continuous structure to which are attached, in a plurality of respective areas, components for respective electronic apparatus, and one particular apparatus is formed by separating a particular respective area from one or more other areas.

15. An electronic apparatus according to claim 14, wherein the separation is performed after the thermoset resin has been applied to substantially set over a plurality of regions of the continuous structure.

16. An electronic apparatus according to any of claims 10-15, wherein the mechanical frame comprises one or more stand-offs to define a clearance between one or respective walls of the mould, used to form the protective housing from the thermoset resin, and one or more respective electronic components.

17. An electronic apparatus according to any preceding claim, wherein one or more components are protectively covered prior to the application of the thermoset resin to protect the component(s) from the thermoset resin.

18. An electronic apparatus according to any preceding claim, wherein the electronic components include one or more user interface elements selected from the group comprising an electronic display, keypad/touchpad, and/or camera lens.

19. An electronic apparatus according to any preceding claim, wherein apertures are defined in the thermoset protective cover by the use of one or more removable plugs positioned to create a region into which the thermoset resin does not flow during the setting of the resin.

20. An electronic apparatus according to claim 19, wherein the apertures are arranged to allow for electrical connection of a peripheral device.

21. An electronic apparatus according to any claim dependent on claim 10, wherein the mechanical frame comprises one or more apertures which define corresponding one or more apertures for use in the electrical connection of one or more peripheral devices, the apertures arranged such that the thermoset resin is not able to flow into said apertures during the formation of the protective cover.

22. An electronic apparatus according to claim 21, wherein the apertures are arranged to extend perpendicularly to the direction of insertion of the thermoset resin.

23. An electronic apparatus according to claim 19, wherein the apertures are formed to extend in a plane parallel to a front face of the apparatus in use.

24. An electronic apparatus according to any preceding claim wherein the apparatus comprises one or more defined heat conductive paths which extend through the thermoset protective housing from one or more electronic components towards the outer surface of the protective cover.

25. An electronic apparatus according to claim 24, wherein the defined heat conductive paths are provided by appropriately positioned graphite foils.

26. An electronic apparatus according to any preceding claim, wherein the apparatus comprises a mechanism to provide the apparatus with a number of mechanical configurations.

27. An electronic apparatus according to claim 26, wherein the mechanism comprises one or more cover(s) arranged to inhibit the ingress of thermoset resin during the setting process which would otherwise prevent the mechanism from providing the number of mechanical configurations.

28. An electronic apparatus according to any preceding claim, wherein the electronic components of the apparatus are substantially embedded within the thermoset resin.

29. An electronic apparatus according to any preceding claim, wherein the electronic apparatus is a rechargeable power cell for an electronic device.

30. A front or rear face protective housing for a portable electronic apparatus, the housing formed from a thermoset resin and attachable to another housing to provide a protective cover for the apparatus.

31. A portable rechargeable power cell, wherein the rechargeable power cell comprises a protective housing integrated with the exterior of the power cell, the protective housing being formed from a thermoset resin.

32. A method of forming a portable electronic apparatus, the apparatus comprising a protective housing and electronic components protected by said protective housing, wherein the protective housing is formed by applying a thermoset resin to some or substantially all of the electronic components of the apparatus to substantially integrate some or substantially all the electronic components adjacent the set protective housing with the set protective housing.

33. The method according to Claim 32, wherein the forming of the protective housing comprises the steps of: defining an open potting cavity using a gasket member positioned on said apparatus to encircle said electronic components but to leave a filling aperture, the open potting cavity further defined by a film positioned over the gasket member opposing the apparatus, the gasket member forming a liquid proof joint with the apparatus and the film; filling the potting cavity with liquid potting material and curing the potting material.

34. The method according to Claim 33, wherein the apparatus is a circuit board.

35. The method according to Claim 33 or 34 wherein the film and/or the gasket member are arranged to integrate with the potting material so as to adhere to the potting material as it cures.

36. The method according to any of Claims 33-35 wherein the potting material comprises a thermosetting plastic.

37. The method according to Claims 35-36, wherein the film and the gasket member are comprised using electrically conductive material in order to provide

RF shielding for the integrated electronic components.

38. The method according to any of Claims 33-37, further comprising the step of: supporting the apparatus and potting cavity between a first and second support member during filling of the potting cavity and/or during the curing of the potting material, the first and second support members being kept separate from the potting material.