GB2508837A

GB2508837A - Multilayer manufacturing method utilising mould

Info

Publication number: GB2508837A
Application number: GB1222327.7A
Authority: GB
Inventors: Vannessa Goodship; Bethany Jane Middleton; Ruth Cherrington
Original assignee: University of Warwick
Current assignee: University of Warwick
Priority date: 2012-12-12
Filing date: 2012-12-12
Publication date: 2014-06-18
Also published as: GB201222327D0; WO2014091197A1

Abstract

A method of manufacturing a moulded part (10) with one or more integral electronic components is disclosed. The method includes depositing or forming one or more layers (11) in a mould of a moulding apparatus, the one or more layers including the one or more electronic components, and introducing material into the mould to form the moulded part. The multiple layers may be formed in the mould by spray deposition using a mask to determine the size of the layer. Each of the layers may be heated and cured before forming the next layer of the moulded part. This method can be used to manufacture either top or bottom emitting electroluminescent devices.

Description

Manufacturing method

Field of the invention

The present invention relates, amongst other things, to a manufacturing method and, in particular, to a method of manufacturing a moulded part with one or more integral electronic components.

Background

Electronic products are commonly manufactured by combining several separately-io made components. For example, this may involve assembling components such as printed circuit board assemblies, batteries, and injection-moulded plastic cases.

The manufacture of electronic components, particularly silicon-based electronic components, is well understood. The moulding of plastic parts is also well understood. Is

Some effort has also been directed at bringing together certain aspects of these two manufacturing technologies.

An example of this is described in TEE et at Embedding of electronics within thermoplastic polymers using injection moulding technique', in: Electronics Manufacturing Technology Symposium, 26 IEEE/CPMT International, 2000, p. 10- 18. This document describes electronic sub-systems simultaneously packaged within an automotive structural thermoplastic component during an injection moulding process.

Another example is described in HOEBER et al. Electrical functionalization of thermoplastic materials by Aerosol Jet Printing', in: Electronics Packaging Technology Conference (EPTC), 2011 IEEE i3th, p. 813-818. This document describes aerosol-jet-printing to apply circuit tracks on three dimensional thermoplastic circuit carriers.

Summary

According to a first aspect of the present invention, there is provided a method of manufacturing a moulded part with one or more integral electronic components. The method includes forming one or more layers in a mould of a moulding apparatus, the 3s one or more layers including the one or more electronic components, and introducing material into the mould to form the moulded part with the one or more integral electronic components.

Thus, moulded parts with integra' dectronic components can be efficiently manufactured, for example without requiring separate processes for manufacturing the electronic components, for manufacturing the moulded parts and for assembling them.

The method may include injecting the material into the mould to form an injection-moulded part with the one or more integral electronic components. In other words, the io method may involve an injection-moulding process.

The method may include forming at least one of the one or more layers directly on the mould. The method may include forming a layer on the mould to enable the part to be released from the mould.

The method may include forming at east one of the one or more thyers on a curved surface. Thus, moulded parts with dectronic components (e.g. electroluminescent devices) over curved surfaces can be manufactured.

The method may include forming at least one of the one or more layers by spray deposition. Herein, "spray deposition" is intended to cover processes for depositing material in which the material is atomized to form a spray. The material maybe atomized, for example, by means of an airbrush. The material to be atomized may be in a solution.

The method may comprise positioning a mask over the mould before forming at least one of the one or more layers. The mould and the mask may have corresponding surfaces. Thus, the size, shape and position of layers can be precisely controlled, even when, for example, they are formed on curved surfaces.

The method may indude heating at least one of the one or more layers before forming a next one of the one or more thyers or before introducing the materia' into the mo&d.

In this way, the layers can be dried and/or cured. The method may include heating the mould to heat at least one of the one or more layers.

The method may include forming the one or more layers with respective predetermined sizes, shapes and positions. Thus, the properties of the one or more electronic components can be controfled, for examp'e by electricay connecting or isolating thyers from other layers.

The method may include, after forming the moulded part, forming a ftuther moulded part with at least one different integral electronic component in the same mould.

According to a second aspect of the present invention, there is provided apparatus for io manufacturing a moulded part with one or more integral electronic components. The apparatus is adapted to form one or more thyers in a mould, the one or more huyers including the one or more electronic components. The apparatus is adapted to introduce material into the mould to form the moulded part with the one or more integral electronic components.

The apparatus may include one or more sections for forming respective ones of the one or more layers. The one or more sections may be moveable relative to the mould. The one or more sections may be formed in the body of the mould.

According to a third aspect of the present invention, there is provided a moulded part with one or more integral electronic components. The moulded part includes moulded material and one or more layers including the one or more electronic components. At least one of the one or more layers is bonded to the moulded material. The part is obtainable by the method.

Thus, a durable part with electronic capabilities can be provided.

The one or more layers may be bonded to the moulded material by, for example, interdiffusion, molecular bonding and/or mechanical bonding. The bonding need not be due to the presence of an adhesive. The one or more thyers may be on or partially or fully embedded in a surface of the modded materiaL The material may be a p'astic material. The plastic material may be a thermoplastic material. The thermoplastic material may be polypropylene. The thermoplastic material may be polyethylene. The moulded part may be rigid or flexible.

At least one of the one or more layers may include a polymeric material. At least one of the one or more layers may include a metal. At least one of the one or more layers may include a ceramic material. At east one of the one or more thyers may indude a biomaterial such as pcily(lactic acid).

The outermost of the one or more layers may bean encapsulating layer. For example, this can be for durability and/or safety.

At least one of the one or more layers may include a region for enabling an electrical connection to be made to the one or more electronic components.

At least one of the one or more electronic components may include an organic (or, in other words, plastic or polymer) electronic component.

At east one of the one or more dectronic components may inchide first and second electrode layers and an active hiyer therebetween.

At least one of the first and second electrodes may be a transparent electrode. At least one of the first and second electrodes may include a conductive polymer. The conductive polymer may be poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate).

A dielectric layer may be included between the first and/or second electrode layers and the active layer.

The one or more electronic components may include an electroluminescent device.

The one or more electronic components may include a photovoltaic device and/or a battery.

There maybe provided a modular system including two or more of the parts.

Brief Description of the Drawings

Certain embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 schematically illustrates a part with a bottom-emitting electroluminescent device.

Figure 2 schematically illustrates a part with a top-emitting electroluminescent device.

io Figure 3 illustrates a mouki cavity in a moffid of an injection moffiding apparatus for making a part such as that shown in Figure ib. Atop view and two side views are shown.

Figure 4 is an image of a moulded part with an integral electronic component and of the is motdd from which the part has been ejected. The image is to show that the part has been deanly ejected from the moifid.

Figure 5 is an image of the light emitted by an electroluminescent device in a part manufactured using a first method, which involves screen printing.

Figure 6 is an image of the light emitted by an electroluminescent device in a part manufactured using a second method, which involves airbrushing.

Figure a is an image, taken from the top, of the light emitted by an electroluminescent device in a part manufactured using a third method, which involves injection moulding.

Figure 7b is an image, taken from the side, of the part shown in Figure a.

Figure 8 is a graph showing the mean illuminance of parts manufactured using the first, second and third methods tinder different test conditions.

Figure 9 is an image of a cross-section through a part manufactured using the first method.

Figure 10 is an image of a cross-section through a part manufactured using the second method.

Figure 11 is an image of a cross-section through a part manufactured using the third method.

Figure 12 is a graph showing average layer thicknesses in the parts shown in Figures 9, and ii.

io Figure 13 schematically illustrates an apparatus for manufacturing a moulded part with one or more integra' electronic components. The apparatus is illustrated in different states corresponding to different stages in the method shown in Figure 14.

Figure 14 is a flow diagram of a method of manufacturing a moulded part with one or more integral dectronic components.

Detailed Description of the Certain Embodiments

Referring to Figure 1, a part 10 with one or more electronic components ba is shown.

In this example, the one or more electronic components ma correspond to an electroluminescent device ma. The part lois obtainable by several of the methods described herein. The part 10 includes a substrate iob and one or more layers 11. In this example, the part 10 includes a first layer 11, a second layer 112, a third layer 113, a fourth layer 114 and a fifth layer 115 on the substrate iob. However, the part 10 may include fewer or more layers 11. In this example, all of the layers 11 are part of the electroluminescent device ma. However, one or more layers 11 may not be part of the one or more electronic components ba. For example, one of the layers 11 may be an encapsulating layer.

The first hiyer iii includes a conductive po'ymeric material, nam&y poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT: PSS). The first kyer ii acts as a transparent dectrode layer. The second layer 112 includes one or more regions of silver on the substrate lob along one or more sides of the first layer iii. The regions are in &ectric& contact with the first layer iii. The second layer 115 acts as a busbar to ensure even charge distribution across the first layer l1 when the device ioa is in use.

The third layer 113 includes a phosphor material and acts as a light-emitting layer. The fourth layer 114 includes a ceramic material and acts as a dielectric layer. The fifth layer includes silver and acts as a rear electrode layer. The substrate iob is a plastic material such as polyethylene.

Electrical connections 12 can be made to the part 10. In particular, a first &ectrica connection 12 can be made to the busbar 112, at least a part of which is not covered by any of the other layers 11. A second electrical connection 122 can be made to the rear electrode 115.

The part 10 (in') includes an electroluminescent device ma (ma') in the form of a Jo bottom-emitting electrohiminescent device. Light is emitted through the transparent electrode layer i1 at the bottom of the device ba (ioa') and then through the substrate iob.

Referring to Figure 2, a part 10 (in") including atop-emitting electroluminescent device ba (ioa") is shown. Here, the order of the first, third, fourth and fifth layers 11k, 113, 114, 115 on the substrate iob is reversed and so Bght is emitted through the transparent electrode hiyer 1i at the top of the device ba (ioa"). This configuration is preferable when the substrate iob is opaque, for example when the substrate iob includes polypropylene. The rear electrode layer n5, which is the lowermost layer ii, has an extended region which is not covered by any of the other layers 11 so that a first electrical connection 12 can be made to it. The busbar layer 112 is provided on the substrate iob and in electrical contact with the transparent electrode layer iii. A second electrical connection 122 can be made to the busbar 112.

Using a first method, a part 10 (io') with a bottom-emitting electroluminescent device ma (ioa') was produced by sequentially screen printing first, second, third, fourth and then fifth layers 111, n, 113, 114, 115 onto a substrate iob.

The layers 11 were formed from commercially-available materials. A CLEVIOSTM PEDOT:PSS-based conductive polymer paste was used to form the transparent electrode layer iii. This was obtained from H C Starck (Germany) and is now obtainable from fleraeus (Germany). Parts 10 were also manufactured using the first, second and third methods described herein using other PEDOT:PSS pastes such as Orgacon'TM paste (obtained from AGFA materials). These parts 10 were found to have similar properties. A phosphor paste including ZnS:M203 and a Cu activator was used to form the light emitting layer 113. A ceramic paste was used to form the dielectric layer 114. A silver paste was used to form the busbar layer 112 and the rear electrode layer 115. These three pastes were all obtained from Electra Polymers (UK). The substrate iob was a flat, 3-mm-thick LexanTM p&yc.arbonate sheet. This is a clear material.

The layers 11 were screen printed by using a squeegee to force the paste through a screen. The screen included a piece of mesh stretched over a frame. Masks were used to control the size, shape and position of the layers ii.

io After printing each layer ii, the device 10 was heated in an oven to dry and/or cure the layer ii. A heating regime recommended by the manufacturers of the kyer materia' was used. The heating regimes are shown in Table 1.

Table 1: Heating regimes used in the first, second and third methods.

First method Second method Third method Oven. Oven. Mould Time Time Time Temperature Temperature Temperature (°C) (°C) (°C) PEDOT:PSS 130 900 130 300 65-70 120-150 Phosphor 130 iSo 130 120 65-70 90-120 Dielectric 130 240 130 150 65-70 120-150 Silver 130 120 130 90 65-70 60-90 Using a second method, a part 10 (io') with a bottom-emitting electroluminescent device ba (ioa') was produced by sequentially airbrushing first, second, third, fourth and then fifth thyers 11k, 112, 113, 114, 115 onto a substrate iob.

The pastes used in the first method were also used in the second method. However, the pastes were modified to make them suitable for airbrushing (for example so that they had a viscosity of around 35 to 6o centipoise). The pastes were diluted using a suitable solvent, namely methyl ethyl ketone (MEK). This solvent was selected by comparing the functional groups of various solvents with the functional groups of the layer materials. A mixing ratio of two-parts MEK to one-part paste was used. This ratio was determined by experiment.

The substrate iob used in the first method was also used in the second method.

The airbrushing was performed using a dual-action airbrush with push button activation. The airbrush had a nozile diameter of 0.30 mm. The layer materia's were provided from cm3 glass jars with suction lids. A different jar was used for each layer material. The airbrush was used with a compressor with an air output of 23 litres per minute and a working pressure of 3 to 4 bar.

Masks were used to control the size, shape and position of the layers ii.

io After depositing each layer ii, the device 10 was heated in an oven to dry and/or cure the layer ii. A modified heating regime which had been estabflshed for the modified layer material was used. The heating regimes are shown in Table 1.

Using a third method, a part 10 (io") with a top-emitting electroluminescent device is ba (ma") was produced by sequentially airbrushing first, third, fourth, fifth and then second thyers iii, fl3, 114, 11 112 onto a part of a moffid and then injection moulding a substrate iob over the layers ii.

Referring to Figure 3, a mould cavity 30 in a mould 40 (Figure 4) is shown. The mould cavity 30 has various features, including flat regions 3oa, shallow (40-to 100-mm radius) curved regions 30b and sharp (1-mm radius) curved edges 3oc. A part of the mould 40 is shown in Figure 4.

Before depositing the first layer 11, a release agent, namely ACMOS 82-2405 release agent, was applied to the mould 40.

Masks were positioned over the mould 40 to control the size, shape and position of the layers ii. The masks had been moulded using the mould 40 and so the mask and the moidd 40 had corresponding surfaces.

The materials used in the second method for forming the layers 11 were also used in the third method. The same airbrush was also used.

After depositing each layer 11, the device 10 was heated to dry and/or cure the layer 11.

The heat was applied by heating the mould 40 using electric cartridge heaters. The heating regimes are shown in Table 1. Drying times varied slightly between samples -10-due to variations in the thicknesses of the layers ii and the temperature of the mould 40.

After app'ying, and heating, the fifth layer 11, an injection moukling process was carried out to form the substrate iob over the layers 11.

The injection-moulding machine used was a Sandretto Micro 30.

Polypropylene was used as the injection-moulding material. Polypropylene is a cheap, io commodity pthstic and is stable. It also does not require any pre-drying and can be processed at relatively low temperatures. P&ypropyene is an opaque material.

The injection-moulding process was carried out using an injection pressure of 1950 bar.

is Finally, the part 10 was ejected from the mould 40.

Referring to Figure 4, the ejected part 10 and the mould 40 are shown. The slight residue which can be seen in the mould 40 is the release agent, rather than any of the materials used to form the layers ii. Thus, the layers ii and the substrate iob have adhered well to one another.

Referring to Figures j, 6 and 7 (a and b), the light emitted by examples of parts 10 produced using the first, second and third methods respectively are shown. Suitable alternating voltages were applied between the electrodes 111, ii to cause the electroluminescent devices ma to emit the light.

Illuminance measurements were performed on examples of parts 10 made using the first, second and third methods. These particular parts 10 included flat, 4 x 4 cm clcctrolumincsccnt deviccs ba.

An alternating current (AC) power supply with a variable-frequency and variable-voltage output (ioo to 400 Hz; 100 to 300 V RMS) was used. AVelleman I-TPSio handh&d oscifioscope was used to measure the frequency and RMS voltage of the output.

-11 -A Reed ST-13o1 light meter was used to measure the illuminance of the part 10. A holder was used to hold the light meter in a fixed position relative to the electroluminescent device ma.

Measurements were performed under first, second, third and fourth test conditions.

The test conditions involved different voltages (V) and/or frequencies (F), as shown in

Table 2.

Table 2. The different test conditions cOI OIl F (Hz) V (V RMS) 1sL 400 300 9nd 100 300 3rd 400 100 4th 100 100 For each measurement, the alternating voltage was applied for 60 seconds before the reading was taken. This was because the light emitted by the device 10 increased in intensity when the voltage was first applied but reached a steady-state in less than seconds. Five samples of each part 10 were measured. The measurements were i repeated five times for each sample.

The results of the illuminance measurements are shown in Tables a, 3b and c and in Figure 8.

Table a. Illurninance of parts made using the first method Test Ifluminance (lx) Relative condition standard Mean Standard deviation (SD) Mean -SD Mean + SD deviation (%) 1st 168.96 13.03 155.93 181.99 7.71 0nd 56.92 4.30 52.62 61.22 7.56 8.88 3.87 15.01 22.75 20.47 4th 7.36 1.47 5.89 8.83 19.95 -12 -Table 3b. illuminance of parts made using second method Test Tiluminance (lx) Relative condition standard Mean Standard deviation (SD) Mean -SD Meal' + SD deviation (%) Vt 287.9 35.21 252.68 323.12 12.23 8o.8 86.6 7.23 3rd 66.85 6.72 60.13 73.57 io.o6 4th 21.71.68 20.04 23.39 7.73 Table 3c. Illurninance of parts made using the third method Test iliwninance (lx) Relative condition standard Mean Standard deviation (SD) Mean -SD Mean + SD deviation (%) 44.67 14.22 30.44 58.89 31.85 2nd 19.75 7.32 12.43 27.07 37.06 3 12.00 4.69 7.31 16.69 39.09 4th 733 3.07 4.26 10.41 41.96 The basic airbrushed parts 10, that is to say those produced using the second method, had a higher ifluminance than the screen-printed parts 10, that is to say those produced using the first method. The moulded parts 10, that is to say those produced using the third method, had the lowest illuminance.

io The first test condition (400 Hz, 330 V RMS) gave the highest ifluminances. Under the first test condition, the screen-printed parts 10 had a mean ifluminance of 169.0 ± 13.0 lx and the basic airbrushed parts iohad a mean ilhiminance of 287.9 ± 35.2 lx. Thus, the basic airbrushed parts 10 are around 70 % brighter than the screen-pnnted parts 10. Under the first test condition, the moulded parts 10 had a is mean illuminance of 44.7 ± 14.2 lx, that is to say around 15% of the illuminance of the basic airbrushed parts 10.

Referring to Figures 9, 10 and ii, cross-sections through examp'es of parts 10 produced using the first, second and third methods respectiv&y are shom. The parts 10 are examples of those on which the illuminance measurements were performed.

The parts 10 were sectioned, mounted and polished, and then viewed using a Zeiss AxioLab Ai microscope.

The screen-printed part 10 and the basic airbrushed part 10 have a relatively even layer structure. In contrast, the moulded part 10 has a relatively uneven layer structure.

-13 -The screen-printed part 10 and the basic airbrushed part 10 have voids 90 in the phosphor layer 113 and/or at the interface between the phosphor layer 113 and the PEDOT:PSS layer 1i. In contrast, the moifided part 10 does not have any voids. The parts 10 were all prepared for microscopy in the same way. Thus, the voids 90 in the screen-printed part 10 and the basic airbrushed part 10 are likely to have been formed when these parts 10 were produced.

The voids 90 are indicative of suboptimal formation of phosphor layer 113 and/or suboptimal adhesion between the phosphor layer 113 and the PEDOT:PSS layer iii. I0

The absence of voids in the moulded part 10 can be attributed to the high pressure associated the injection-moulding process (1950 bar) having the effect of eliminating any voids created when the layers 11 were formed.

Referring to Figure 12, average thicknesses of the layers 11 in the parts 10 are compared.

AxioVision 4.8 software was used to measure the thicknesses of the layers ii.

The average layer thicknesses were similar in the basic airbrushed parts 10 and the moulded parts 10 (in which the layers 11 were also formed by airbrushing). Despite this, as described hereinbefore, the moulded parts 10 have a considerably lower illuminance than the basic airbrushed parts 10 (see Figure 8). Furthermore, the moulded parts 10 have a lower-quality layer structure than the basic airbrushed parts 10 (see Figures 10 and ii). These differences may be due to the lower temperatures used to dry and/or cure the layers 11 in the moulded parts 10. They may also be due to the movement of the polypropylene material over the layers ii during the injection-moulding process.

Referring to Figures ia to ig, apparatus 100 for manufacturing an injection-moulded part 10 with one or more integral electronic components ma is shown.

In this example, the apparatus 100 includes an injection-mou'ding machine 101 with a reciprocating screw ioia. However, the apparatus 100 may include another type of injection-moulding machine.

The apparatus 100 includes a mould 102. The mould 102 includes a first mould part 102a and a second mould part lo2b. The mould 102 can be opened or closed by moving the first and second mould parts ioa, 102b in r&ation to each other. The mould 102 includes a spnue 1o2c through which the material 110 to form the substrate iob is injected into the mould 102.

The mould 102 may be coated with a coating such as polytetrafluoroethylene (PTFE).

This may reduce the need to use a release agent and/or may improve the surface finish of the part 10. I0

In this example, a sing'e moffid 102 with a sing'e cavity 102d is shown. However, there may be plural moulds 102 and/or cavities 102d.

The apparatus 100 also includes a device 103 for forming one or more layers 11 on the mould 102 (hereinafter referred to as a "layer-forming device").

The thyer-forming device 103 may include a section 104 for each of the layers ii to be formed.

In this example, the device 103 includes four sections 104, each of which is for forming a respective layer ii by spray deposition. For clarity, only one section 104 is shown.

However, the device 103 may include fewer sections 104 or more sections 104. The device 103 may include sections 104 of another type. The device 103 may include two or more types of section 104. This will depend upon the layers 11 to be formed.

Sections 104 can be added to or removed from the apparatus 100.

The section 104 includes a head ioa and a mask 104b. The head ioa and the mask lo4b may be movable in relation to each other. In some examples, the heads ioa and the masks lo4b maybe independently movable. The section 104 includes or is in communication with a source (not shown) of the material in to form the layer ii. In this example, the section 104 includes an airbrush. Thus, it also indudes or is in communication with a source (not shown) of compressed air.

The sections 104 are movable into and out of the open mould 102. The sections 104 may be mounted on a movable plate (not shown). The plate may rotate to move a -15 -particular one of the sections 104 into a position for forming the layer 11. The sections 104 maybe independently movable, for example by robotic arms.

In some examp'es, the sections 104 need not be movaNe. For example, the sections 104 may be fixed in suitable positions outside the mould 102 for forming the layers 11.

The sections 104 (in particular the heads 104a) may be fixed in positions in the mould 102. The sections 104 (in particular the heads 104a) may be integral parts of the mould 102.

io The spray is formed in the head ioa and exits the head ioa through one or more nozzles.

The head ioa may be stationary or can be moved while depositing the layer ii.

is The properties (e.g. pressure) of the spray and the length of time during which the spraying is performed can be controlled to control the thickness of the layer ii.

Typically, thicknesses may be between 200 nm and tens of microns. However, they may be more or less than this.

The mask lo4b is for controlling the size, shape and position of the layer 11. The mask 104b may have a curved surface which follows the curves in the surface of the mould 102. Thus, the layers 11 can be deposited more accurately on a curved surface of the mould 102. In some examples, one or more of the sections 104 need not include masks lo4b.

The apparatus 100 includes a heating arrangement 105 for heating and thus drying and/or curing the layers ii. In this example, the heating arrangement 105 heats the mould 102 which, in turn, heats the layers ii formed thereon. The heating arrangement is adapted to raise the temperature of the mould and hence one or more of the layers ii to a suitable temperature for drying and/or curing it. For examp'e, the temperature may be between 6 and 130 °C. The heating arrangement io may inchide channels in the mould 102 through which a hot fluid (for examp'e water, steam or oil) can be passed. The heating arrangement io may include one or more electric heaters (for example cartridge heaters) arranged on the mould 102. In some examples, the apparatus 100 need not include a heating arrangement 105.

The injection-moulding machine 101 may correspond to a conventional injection-moulding machine.

The pressure at which the material 110 is injected into the mould 102 may be controfled in such a way as to remove any voids from the deposited layers 11. For example, the highest pressures which can be used without damaging the layers 11 may be established.

The position and/or alignment of the sprue ioc relative to the region in which the io layers 11 are formed maybe selected such that, when the materia' 110 is injected into the moifid 102, the risk of damage to the layers 11 is minimised. For example, the material 110 may be injected in a direction away from the layers ii.

The apparatus 100 preferably includes a controller (not shown). The controller can contr&, for example, the opening and dosing of the mould 102, the operation of the layer-forming device 103, the operation of the heating arrangement 105, and/or the operation of the injection-moifiding machine 101. The controller may include a computer. The controller can be programmed so as to enable, for example, a plurality of parts 10 to be manufactured with the same or different layer structures ii and hence electronic capabilities.

Referring to Figures ia to ig and Figure 14, a method of manufacturing a moulded part 10 with one or more integral electronic components ba is shown. In this example, the method is performed by the apparatus 100. However, the method 100 may be performed by another type of apparatus.

The method includes forming one or more layers 11 in the mould 102 (step Si).

The layer-forming device 103 and, in particular, the section 104 for depositing the first layer ii1, is moved into a suitable position (step Sia). For example, the head ioa and the mask io4b may be aligned with the region of the mould 102 on which the thyer it1 is to be formed.

The section ioa is then operated to deposit the layer lii (step Sib). For example, the material iii for forming the layer lii may be sprayed for a predetermined length of time. -17-

The heating arrangement 105 is then operated to heat the layer iii (step Sic).

Thermometry (not shosm) may be included in the apparatus 100 and maybe used to contrcil the temperature to which the layer 11 is heated.

It is determined by the controller whether there are any more layers 11 to be formed (step Sid).

If there are more layers 11 to be formed, then these layers 11 are formed in a Jo corresponding way to that described hereinbefore.

If there are no more layers 11 to be formed, then the layer-forming device 103 is removed from the mould 102 (step Sic).

is Moulding is then carried out (step 52).

In particular, the mould 102 is closed (step S2a).

The injection-moulding machine 101 is operated to inject the material 110 for forming the substrate iob into the mould 102 (step S2b).

The mould 102 is then opened and the part 10 is ejected from the mould 102 (step 52c).

This may be done using ejection pins 106. The opening of the mould 102 and the ejection of the part 10 maybe delayed to allow the part 10 to cool.

It is determined by the controller whether there are any more parts 10 to be formed (step S3). If there are more parts 10 to be formed, then these parts 10 are formed as described hereinbefore. If there are no more parts 10 to be formed, then the method ends. 3°

Depending upon the apparatus 100 and/or upon the moulded part 10 being manufactured, certain operations need not be performed or may be performed in a different order. For examp'e, the layer-forming device 102 may not be movable and so need not be moved into position (step Sia) or removed from the mould 102 (step Sic).

The heating of the layers ii (step Sic) need not be performed after forming each of the -18-layers 11. The layer-forming device 102 maybe fixed in the mould 102 and so the mould 102 may be closed (step S2a) before the layers 11 are formed (step Si).

Moulded parts 10 with integral electroluminescent devices ma as described herein can have many different applications. They can be used as an alternative to conventional lighting systems. They can be used to in places where conventional lighting systems are disadvantageous due to their size, weight and/or cost. For example, objects such as glove boxes, cupboards, traffic control devices, safety clothing, phone casings, electrical sockets and so forth can be provided with built-in lighting capabilities. I0

It will be appreciated that many other modifications may be made to the embodiments hereinbefore described.

The moulded part 10 may be different.

For example, the part 10 may include a different electroluminescent device ma. One or more of the thyers 11 may indude different materials. For examp'e, the light-emitting layer 113 may include a different phosphor material and/or may emit a different colour of light. The transparent electrode layer lii may include a different transparent conductive polymer material. The rear electrode 115 may include a different conductive material. The rear electrode 115 may include a transparent conductive material such as PEDOT: PSS. There may be no dielectric layers 114 or more than one dielectric layer 114.

There may be a single layer including a mixture of a light-emitting material and a dielectric material.

The part 10 may include two or more electroluminescent devices ba. Different regions of the part 10 may emit light in response to electrical signals being provided to different respective sets of electrical connections. Thus, the part 10 may form part of a display or a sign.

The part 10 may be provided with an encapsulating layer ii for durability and/or safety.

A material which adheres to the underlying layers ii but not to the mould 102 is preferably selected for forming the encapsidating layer ii. The encapsulating layer ii maybe absent in certain regions, for example to enable electrical connections to be made to the part 10.

The substrate tob may be moulded to have any suitable shape. For example, the substrate iob may have a curved surface over which an electronic component ba is formed. The substrate iob may have a space for holding a battery or an additional electronic component such as an inverter. The substrate iob may be rigid or flexible.

The part 10 may include one or more electronic devices ba other than electroluminescent devices.

The part 10 may include an integral photovoltaic device ba. The photovoltaic device io ba is preferably an organic photovoltaic device. The photovoltaic device ba may have a similar layer structure to the electroluminescent device boa and, in particular, may include a similar arrangement of two electrode layers and an intermediate active layer.

Instead of a phosphor layer 113 as the active layer, the photovoltaic device boa includes one or more materials which exhibit the photovoltaic effect. For example, the active is layer may be formed from a poly(3-hexylthiophene):[6,6]-Phenyl C6i butyric acid methyl-ester (P3HT:PCBM) blend dissolved in a co-solvent mixture. This material can also be spray deposited, for example using an airbrush. Thus, the methods and apparatuses described herein can be readily used to manufacture a part 10 with an integral photovoltaic device boa.

The part 10 may include an integral battery boa. The battery boa is preferably an organic battery. For example, the battery boa may be an organic radical battery. Such a battery boa may also be manufactured using the methods and apparatuses 100 described herein.

A part 10 may include, for example, an integral photovoltaic device ba, a battery ba and an electroluminescent device boa. In this way, the part 10 can be used to generate electricity during the daytime, store the energy, and then illuminate at night.

The part 10 may be a sensor. For example, the part 10 may include a smart material, such as a shape-memory polymer, which interacts with integral electronic components ba.

The part 10 may include an integral radio-frequency identification (RFID) tag ioa.

The part 10 may include one or more integral electronic components ba such as transistors, capacitors, electrical connections, and so forth.

A modular system inchiding two or more of the parts 10 may be produced.

For example, the modular system may include two or more parts 10 with integral photovoltaic devices ma. The parts 10 can be connectable to one another so that electrical connections can be made therebetween in such a way that the electrical output of one part lois added to the output of the other. Thus, a photovoltaic device can be assembled with any size and shape, depending upon the number of parts 10 and how they are connected together.

The modular system may include a part 10 with an integral photovoltaic device ma and/or a part 10 with an integral battery ba and a part 10 with an integral electroluminescent device ba, which are operativdy connectable to one another.

At east some of the materials in the part 10 maybe biodegradable or compostable. At least some of the materials in the part 10 may be biocompatible. At least some of the materials in the part 10 may be bioresorbable.

The manufacturing method and the apparatus 100 may be different from those hereinbefore described.

For example, instead of an airbrush, an ultrasonic or electrostatic atomizer may be used to form the spray.

One or more of the layers 11 may be formed using a process other than spray deposition. For example, an additive-manufacturing (3D-printing) process may be uscd. Other printing mcthods such as inkjct printing may bc uscd.

Materials in the form of powders or nanopowders may be applied using a spray-coating process.

The layers 11 may be heated in a different way. For example, the mould 102 and/or the layers 11 may be heated using hot gases or steam or by non-contact methods such as electromagnetic induction, infrared radiation or electrical resistance. The mould 102 may subsequently be cooled using channel cooling. This can make the heating and cooling more rapid.

The method may invohre a monding process other than injection moulding. For example, it may involve compression moulding, blow moulding or the like.

Where the part 10 includes two or more different electronic components ba, these can be produced from a single sequence of layers by using an appropriate sequence of masks lo4b. In this case, there will be at least one layer ii which has two or more io different regions respectiv&y included in two or more different &ectronic components ba. -22-

Claims

Claims 1. A method of manufacturing a moulded part with one or more integral electronic components, the method comprising: forming one or more layers in a mould of a moulding apparatus, the one or more layers comprising the one or more electronic components; and introducing material into the mould to form the moulded part with the one or more integral electronic components.

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2. A method according to claim i, comprising forming at least one of the one or more thyers directly on the motfid.
3. A method according to any preceding claim, comprising forming at least one of the one or more layers on a curved surface.
4. A method according to any preceding claim, comprising forming at east one of the one or more layers by spray deposition.
5. A method according to any preceding claim, comprising positioning a mask over the mould before forming at least one of the one or more layers.
6. A method according to any preceding claim, comprising heating at least one of the one or more layers before forming a next one of the one or more layers or before introducing the material into the mould.
7. A method according to any preceding claim, comprising forming the one or more layers with respective predetennined sizes, shapes and positions.
8. Apparatus for manufacturing a inoulded part with one or more integral electronic components, the apparatus adapted to: form one or more thyers in a mould, the one or more layers comprising the one or more electronic components; and introduce material into the mould to form the moulded part with the one or more integral dectronic components.
9. Apparatus according to claim 8, comprising one or more sections for forming respective ones of the one or more layers.-23 -
10. A moulded part with one or more integral electronic components, wherein the part comprises moulded material and one or more layers comprising the one or more electronic components, at east one of the one or more ayers being bonded to the moulded material, and wherein the part is obtainable by a method according to any one of claims 1 to 7.
ii. A method according to any one of claims 1 to 7, apparatus according to claim 8 or 9, or part according to claim 10, wherein at least one of the one or more layers Jo comprises a p&ymeric material.
12. A method according to any one of claims ito 7 and ii, apparatus according to any one of claims 8, 9 and ii, or pait according to claim 10 or 11, wherein the outermost of the one or more layers is an encapsulating layer.
13. A method according to any one of daims ito, ii and 12, apparatus according to any one of claims 8,9, 11 and 12, or a part according to any one of claims 10 to 12, wherein at east one of the one or more electronic components comprises first and second electrode sayers and an active sayer therebetween.
14. A method according to any one of claims ito 7 and 11 to 13, apparatus according to any one of claims 8, 9 and 11 to 13, or a part according to any one of claims 10 to 13, wherein the one or more electronic components comprise an electroluminescent device.
15. A method according to any one of claims ito 7 and 11 to 14, apparatus according to any one of claims 8, 9 and 11 to 14, or a part according to any one of chUms 10 to 14, wherein the one or more electronic components comprise a photovoltaic device and/or a battery.