WO2005112526A1

WO2005112526A1 - Printed wiring board, manufacturing method and electronic device

Info

Publication number: WO2005112526A1
Application number: PCT/FI2005/050160
Authority: WO
Inventors: Pauliina MANSIKKAMÄKI; Tero Peltola; Juulia Loisa
Original assignee: Aspocomp Technology Oy
Priority date: 2004-05-17
Filing date: 2005-05-16
Publication date: 2005-11-24
Also published as: FI117234B; FI20045179A0; FI20045179A; EP1747704A4; WO2005112526A8; JP2007538394A; EP1747704A1

Abstract

A printed wiring board, an electronic device and a method for manufacturing a printed wiring board. A printed wiring board (1) comprises an insulating layer (2, 2a, 2b) and a circuit pattern (3, 3a, 3b) arranged on at least one surface of the insulating layer (2, 2a, 2b) and made of a conductive material. At least one surface of the insulating layer (2, 2a, 2b) is provided with a support pattern (6, 6a, 6b), which comprises material lines (7, 7a, 7b) arranged at a distance from each other.

Description

PRINTED WIRING BOARD, MANUFACTURING METHOD AND ELECTRONIC

DEVICE

BACKGROUND OF THE INVENTION [0001] The invention relates to a printed wiring board comprising an insulating layer and a circuit pattern arranged on at least one surface of the insulating layer and made of a conductive material. [0002] The invention also relates to an electronic device comprising at least one printed wiring board, which comprises an insulating layer and a circuit pattern arranged on at least one surface of the insulating layer and made of a conductive material. [0003] The invention further relates to a method for manufacturing a printed wiring board, in which method a circuit pattern is arranged on at least one surface of an insulating layer. [0004] It is known that almost all electronic products include some sort of printed wiring board. A variety of components, such as microprocessors and other integrated circuits, resistors, capacitors and other similar standard components, as well as special components, can be attached to the printed wiring board. The printed wiring board acts as a connection and switching base for components. In addition, the printed wiring board transmits signals and op- erating voltages to and from the components. The printed wiring board also transmits waste heat of the components away, acts as a mechanical support structure for the components and protects the components from electromagnetic interference. [0005] On the surface of the printed wiring board there is a conduc- tor layer constituting a circuit pattern, which is electrically conductive. A circuit pattern is designed in such a manner that the components to be arranged on the printed wiring board function in the intended manner. The printed wiring board is made of a blank or laminate comprising an insulating layer made of a non-conductive material or a basic layer coated with a conductive material, such as copper. The insulating layer is typically made of thermosetting plastic or thermoplastic. In the manufacturing process of a printed wiring board, useless conductive material of the circuit pattern is removed from the surface of the basic layer, whereupon the circuit pattern remains on the surface. The useless conductive material is removed, for instance, by etching or other similar manner. A circuit pattern can also be grown onto the insulating layer or it can be manufactured in a separate process and transferred onto the surface of the insulating layer. There are also other known methods for manufacturing printed wiring boards. [0006] The printed wiring board can also be a multilayer printed board consisting of several conductor layers separated from each other by means of electrically insulating material layers. Multilayer printed boards are described in the patent application EP 1 1 19 227, for example. [0007] As is known, development of most electronic devices aims at device constructions which are smaller and smaller and more versatile. Also, the outer appearance of devices is shaped more freely because the design of the devices has become a very important factor in the product competition between different device manufacturers. [0008] A problem of known printed wiring boards - both single-layer and multilayer printed boards - is that they have a shape of a straight two- dimensional plane surface. It is difficult, maybe even impossible to shape them to be three-dimensional without breaking the structure of the printed wiring board, which sets limits to reducing the size of the device at least to some extent, but most of all it limits the design of the device. Because of the shape of the electronic device it may be necessary to use a printed wiring board which is divided into several different parts, which are combined with each other by flexible wiring boards. Assembling such a printed wiring board structure is complicated and expensive. It is also problematic that sometimes, because of spatial problems or for convenience, a push button - e.g. a current switch of a mobile terminal - of an electronic device has to be arranged on the side of the device - e.g. at the end of the mobile terminal - which is perpendicular to that side on which the majority of the switches are and according to which the printed wiring board is arranged. As this switch is thus pressed, the printed wiring board is subjected to bending force, which may, in the course of time, detach the switch from the printed wiring board.

BRIEF DESCRIPTION OF THE INVENTION [0009] It is an object of the invention to provide a new and improved printed wiring board, a method for manufacturing a printed wiring board and an electronic device, which avoid the above problems. [0010] The printed wiring board of the invention is characterized in that at least one surface of the insulating layer is provided with a support pattern, which comprises material lines arranged at a distance from each other. [0011] The electronic device of the invention is further characterized in that at least one surface of the insulating layer is provided with a support pattern, which comprises material lines arranged at a distance from each other. [0012] The method of the invention is further characterized by providing at least one surface of the insulating layer with a support pattern, which comprises material lines arranged at a distance from each other. [0013] The essential idea of the invention is that in the printed wiring board, not only a circuit pattern but also a mechanical support pattern are arranged on the surface of the material layer made of a conductive material. The support pattern is most preferably formed of the same conductive layer as the circuit pattern. The support pattern comprises material lines, whereby their distance from each other, their width, shape and direction are selected according to the mechanical and design requirements set to the printed wiring board. [0014] The invention provides the advantage that the support pattern increases design possibilities of the printed wiring board essentially. In addition, the printed wiring board can be utilized as a light stiffening element of an electronic device, which, however, provides a sufficient mechanical support. [0015] The essential idea of a preferred embodiment of the invention is that the insulating layer is made of thermoplastic or a thermoplastic composite. [0016] It provides the advantage that the printed wiring board can be shaped to be three-dimensional either at elevated temperature or even at room temperature by various techniques. [0017] The essential idea of a second preferred embodiment of the invention is that the printed wiring board is a multilayer printed board, which comprises several insulating layers one upon the other as well as conductor layers and mechanical support patterns arranged between them. The support patterns in the different layers are preferably arranged in such a manner that they form a line pattern where different support lines stagger. [0018] It provides the advantage that the staggered support pattern is very light but increases design possibilities of the multilayer printed board considerably. [0019] The essential idea of a third preferred embodiment of the invention is that the method for manufacturing a printed wiring board comprises providing the components mounted on the printed wiring board with a protective layer, which supports the components during the manufacture of the printed wiring board. [0020] It provides the advantage that the components remain in their places on the printed wiring board during this manufacture. [0021] The essential idea of a fourth preferred embodiment of the invention is that in the method for manufacturing a printed wiring board, the printed wiring board, the components mounted thereon and the protective layer arranged on them are arranged into a mould, such as an injection mould, and plastic is mould onto the printed wiring board. [0022] It provides the advantage that the printed wiring board can be quickly integrated into a plastic product without many operating stages.

BRIEF DESCRIPTION OF THE FIGURES [0023] The invention will be described in greater detail in the attached drawings, in which Figure 1 schematically shows a perspective view of a printed wiring board of the invention, Figure 2 schematically shows a perspective exploded view of a multilayer printed board of the invention, Figure 3 schematically shows a part of a third printed wiring board of the invention from above, Figure 4 schematically shows a part of a fourth printed wiring board of the invention from above, Figure 5 schematically shows a part of a fifth printed wiring board of the invention from the side and partly in cross-section, Figure 6 schematically shows a sixth printed wiring board of the invention, and Figure 7 schematically shows the printed wiring board shown in Figure 6 from the side and fixed to the electronic device. [0024] For the sake of clarity, the invention is simplified in the figures. Like parts are denoted by the same reference numbers in the figures. DETAILED DESCRIPTION OF THE INVENTION [0025] Figure 1 shows a perspective view of a printed wiring board of the invention schematically. [0026] A printed wiring board 1 comprises an insulating layer 2, which, according to its electrical properties, is an insulator. In the presented embodiment, the insulating layer 2 is made of thermoplastic. The manufacturing material of the insulating layer 2 may comprise, for instance, polyolefin, such as polyethylene or polypropylene, polymethyl pentene (PMP), polystyrene (PS), polyether sulfone (PES), polyphenylene ether (PPE), polyphenylene sulfone (PPS) or the like. The insulating layer 2 can also be made of thermosetting plastic, an elastomeric material, a thermoplastic elastomer or any other material having the necessary electrical properties, resisting the chemicals used in the manufacture of printed wiring boards and fulfilling other requirements set to the printed wiring board 1. The insulating layer 2 may comprise one single material layer or it may contain several layers made of different materials. Besides a matrix material, the insulating layer 2 can comprise reinforcements, such as fibre reinforcements, mixed with the matrix material, or other filling materials. [0027] In the figure, the surface illustrated as the upper surface of the Insulating layer 2 is provided with a circuit pattern 3. In short, the printed wiring board 1 is made of a blank or laminate comprising the insulating layer 2 and a conductor layer, which covers the insulating layer entirely. Useless material of the conductor layer has been removed from the surface of the insulating layer 2 in the circuit pattern 3 by a method known per se, such as by etch- ing, whereupon the circuit pattern 3 has remained on the surface. The conductor layer and the circuit pattern 3 formed thereof are made of a conductive material, which, in this case, is copper but which can also be silver, gold or any other material having a sufficient conductivity. The circuit pattern 3 can also be manufactured by growing it onto the insulating layer. [0028] The circuit pattern 3 includes connecting points 4, which connect electric components to the electric circuit of the circuit pattern 3. In addition, the circuit pattern comprises conductors 5, the purpose of which is to transmit signals and operating voltages to and from the components, heat transmission parts and other similar parts of circuit patterns known per se. It is to be noted that the circuit patterns 3 shown in the figures are presented by way of example and only intended for describing the features of the invention. [0029] There is also a support pattern 6 on the surface of the insulating layer 2. It consists of material lines, i.e. basic lines 7 arranged at a distance from each other and edge lines 8 following the shapes of the circuit pattern 3. The support pattern 6 is formed of the same conductive layer and in the same manufacturing process as the circuit pattern 3. In other words, in this embodiment the lines 7 and 8 of the support pattern are made of copper and provided in such a manner that neither the material forming the circuit pattern 3 nor the material forming the lines 7, 8 of the support pattern 6 have been removed from the conductor layer. However, it is to be noted that it is possible to manufacture the support pattern 6 in a different manufacturing process and with a different method than the circuit pattern 3. [0030] On the upper surface of the printed wiring board 1 the support pattern 6 substantially entirely covers that part that does not comprise the circuit pattern 3. The basic lines 7 of the support pattern 6 form a grid-like pat- tern, the basic shape of which is similar throughout the entire support pattern 6. It is obvious that the basic lines 7 of the support pattern 6 can also be arranged in a shape different from that of Figure 1. Also, the width and the height, i.e. the height from the surface of the insulating layer 2, of the basic bands 7 as well as the distance between them can be different in the different parts of the support pattern 6. [0031] The edge lines 8 of the support pattern 6 form a limit between the support pattern 6 and the circuit pattern 3. The edge lines 8 are arranged at a certain minimum distance from the conductive parts of the circuit pattern 3 so that a circuit pattern area 9 bordering the circuit pattern is formed on the printed wiring board. However, it is to be noted that the edge lines 8 are not essential but the support pattern 6 can also be implemented without them. [0032] The support pattern 6 shown in Figure 1 is electrically insulated from the circuit pattern 3. In a second embodiment of the invention, the support pattern 6 is used as a ground plane of the printed wiring board 1 , in which case the electrical components of the printed wiring board 1 are suitably arranged in contact with the lines 7, 8 of the support pattern. The support pattern 6 can also be used for transmitting the operating voltage or for another similar electrical function. [0033] The support pattern 6 makes the structure of the printed wir- ing board 1 stiffer, whereby the insulating layer 2, one purpose of which is to function as a mechanical support structure, can be made thinner. Due to this, the total thickness and weight of the printed wiring board 1 can be reduced. [0034] The support pattern 6 also increases the mechanical toughness of the printed wiring board, which, together with the fact that the insulat- ing layer 2 is made of thermoplastic, allows the printed wiring board 1 to be moulded into a three-dimensional shape at elevated temperature or, in some embodiments, even at normal room temperature. Due to the support pattern 6, however, the printed wiring board 1 can be manufactured and dimensioned in such a manner that it is a substantially stiff structure at its normal operating temperature, in which case it can be used as an element that stiffens the electronic device or its part. [0035] Although in the printed wiring board 1 shown in Figure 1 the support pattern 6 is formed in the same manufacturing process as the circuit pattern 3, this is not necessary. The support pattern 6 can also be formed be- fore manufacturing the circuit pattern 3, or after it. The support pattern 6 can also be made of a different material than the circuit pattern 3. [0036] Figure 2 shows a perspective exploded view of a multilayer printed board of the invention schematically. [0037] The printed wiring board 1 comprises two layers, i.e. the first layer 10a and the second layer 10b, which are arranged typically undetachably one upon the other in the printed wiring board, which is illustrated by arrows A. For the sake of clarity, the layers are shown separate from each other in Figure 2. It is to be noted herein that the multilayer printed board of the invention can naturally comprise three or more layers 10. [0038] The multilayer printed board 1 can be provided, for instance, by manufacturing a first circuit pattern 3a and a first support pattern 6a onto the surface of a first insulating layer 2a. After this, another blank or laminate comprising a second insulating layer 2b and a conductor layer is attached onto them. A second circuit pattern 3b and a second support pattern 6b are made from the conductor layer. Another possibility is to attach the second insulating layer 2b onto the first layer 10a, i.e. the first circuit pattern 3a and the first support pattern 6a. On top of this layer, a conductor layer is manufactured, and the necessary circuit and support patterns are etched from this layer. The circuit and support patterns 3a, 3b, 6a, 6b can also be manufactured by growing. The circuit and support patterns 3a, 3b, 6a, 6b can also be manufactured in a sepa- rate process and transferred onto the surface of the insulating layer 2a, 2b or by another manner known per se by a person skilled in the art. [0039] Both the first insulating layer 2a and the second insulating layer 2b can comprise several laminated layers. The insulating layers 2a, 2b can also have various thicknesses. [0040] There is a first circuit pattern 3a on the surface of the first insulating layer 2a and, correspondingly, a second circuit pattern 3b on the surface of the second insulating layer 2b. It is to be noted that details of the circuit patterns 3a, 3b are not shown for the sake of clarity. Instead, Figure 2 only shows the circuit pattern areas 9a, 9b. [0041] The first circuit pattern 3a is in connection with the second circuit pattern 3b via the contact structures extending through the second insulating layer 2b. Such structures are known per se and are not discussed in greater detail herein. [0042] Both layers 10a, 10b further comprise a support pattern 6a,

6b. The support pattern 6a, 6b is preferably made of the same material as the circuit pattern in the corresponding layer 10a, 10b and most preferably formed in the same manufacturing process. [0043] The basic lines 7 of the first support pattern 6a are arranged to be staggered with the basic lines 7 of the second support pattern 6b, which is illustrated by means of extra lines L1 , L2 showing the position of the lines. In other words, the positioning of the basic lines 7 is such that parallel basic lines 7 of the different layers are not arranged one upon the other, but, when the printed wiring board is seen from above, the basic lines 7 of the different layers are next to each other. The experiments show that the staggered positions of the basic lines 7 is advantageous when the printed wiring board 1 is moulded into a three-dimensional shape. [0044] Another advantage is that since the distance between the staggered basic lines 7 is greater than in the case where the basic lines are one upon the other, the stray capacitance the lines 7 possibly cause is considerably lower. [0045] The direction, width, density and pattern of the basic lines 7 of the support patterns 6a, 6b can be different in the different layers 10a, 10b. It is not necessary that each layer of the multilayer printed board comprises a support pattern 6 in addition to the circuit pattern 3. Also, parallel basic lines 7 in the different layers 10a, 10b can also be positioned one upon the other, es- pecially if the printed wiring board 1 comprises a considerable number of layers 10a, 10b. [0046] Figure 3 shows a top view of a part of a third printed wiring board of the invention schematically. Figure 3 shows the part of the printed wiring board 1 that comprises a support pattern 6. Different kinds of support patterns 6 can be formed in the different parts of the printed wiring board 1. In the first partial pattern 11 a of the support pattern 6 of the printed wiring board 1 shown in Figure 3, the structure of the basic lines 7 is denser than in the second partial pattern 11 b. For instance, the pattern of the support pattern 6 can be made stiffer in those parts of the printed wiring board 1 where it is subjected to mechanical stress during the moulding or when it is in its place in the electronic device. On the other hand, the support pattern 6 can be made very light in those parts of the printed wiring board 1 that are not so sensitive to load or stress. When the support pattern 6 is designed, other criteria affecting the shape, stiffness and other properties of the support pattern 6 can naturally also be taken into account. [0047] The surface of the printed wiring board 1 comprising the circuit pattern can also include parts which have no support pattern 6 and do not belong to the circuit pattern area. In Figure 3, such a part of the printed wiring board 1 is denoted by reference number 20. [0048] Figure 4 shows a top view of a part of a fourth printed wiring board of the invention schematically. The figure shows the part of the upper surface of the printed wiring board 1 that comprises a support pattern but no circuit pattern arranged on the upper surface. The printed wiring board 1 com- prises a first support pattern 6a on the upper surface of the insulating layer 2 and a second support pattern 6b on the lower surface of the insulating layer 2. In the shown embodiment, on the upper surface of the insulating layer 2 there are parallel basic lines 7a, which are arranged to extend from the top to the bottom. On the lower surface of the insulating layer 2 there are parallel basic lines 7b, the direction of which is arranged perpendicularly to the basic lines 7a of the upper surface. The basic lines of the lower surface are denoted by broken lines. The support patterns 6 of the upper and lower surfaces are arranged so that the malleability, stiffness and other corresponding properties are suitable in view of design and usage of the printed wiring board 1. [0049] The lower surface of the printed wiring board 1 can be provided with both the second support pattern 6b and the second circuit pattern, in which case both sides of the insulating layer 2 comprise a circuit pattern and a support pattern 6a, 6b. In another embodiment, the first surface of the printed wiring board only comprises the circuit pattern 3 but no support pattern 6, whereas on the second surface of the printed wiring board there is only the support pattern 6 but no circuit pattern 3. The support pattern 6 can thus cover the second surface entirely. In a third embodiment, the first surface of the printed wiring board comprises both the circuit pattern 3 and the support pattern 6 and the second surface only comprises the circuit pattern 3. [0050] Figure 5 schematically shows a part of a fifth printed wiring board of the invention from the side and partly in cross-section. The printed wiring board 1 comprises an insulating layer 2 and a conductive layer with both a circuit pattern 3 and a support pattern 6. [0051] Components 12 belonging to the printed wiring board 1 are mounted thereon. The piling of the components 12 is carried out in a manner known per se and is not described in greater detail herein. [0052] On top of the printed wiring board 1 and the components 12 there is a protective layer, which, in the embodiment of Figure 5, is a plastic film 13. The film 13 comprises holes 14 extending through it. [0053] The printed wiring board 1 and its components 12 and films 13 are arranged in a mould cavity of an injection mould such that plastic material to be injected into the mould is pressed against the printed wiring board 1 from the direction shown by arrows I. This is an IML process (In-Mould- Labelling), in which the printed wiring board 1 acts as an insert. It is to be noted that said injection mould is not shown in the figures. [0054] The protective layer protects and supports the components

12 attached to the printed wiring board especially during the injection of plastic material. Otherwise, the plastic material rapidly flowing in the mould cavity could detach components 12 from the printed wiring board 1 in the injection phase. [0055] The printed wiring board 1 to be arranged in the injection mould can be a substantially unshaped two-dimensional printed wiring board or it can be preshaped into a three-dimensional shape. The printed wiring board 1 can maintain its given shape in the injection moulding or its shape can be changed in a controlled manner under the pressure of the plastic material to be injected into the mould. As a result of the injection moulding, a printed wiring board 1 integrated into the plastic material is achieved. The printed wiring board 1 can be completely surrounded by plastic material by also arranging some of the plastic material on the back side of the printed wiring board 1. [0056] The printed wiring board 1 can also be integrated onto the surface of or inside the rubber or other elastomeric material. Depending on the type of elastomer, it can be attached to the printed wiring board 1 , for instance, by cross-linking or by another method known per se. A particularly flexible integrated structure is achieved when the insulating layer or insulating layers 2 of the printed wiring board 1 are made of an elastomeric material. [0057] Because of the holes 14 in the film, the plastic material to be injected comes into contact with the plastic material of the insulating layer 2 through the film 13. This is facilitated by the line pattern of the support layer, which reveals some of the plain surface of the insulating layer 2. If the material of the insulating layer 2 and the plastic material to be injected are selected suitably, a very tight bond is formed between them. The protective film 13 does not necessarily have to comprise holes. [0058] The protective layer can naturally also be used for protecting other printed wiring boards 1 than the ones treated by injection moulding. [0059] The protective layer can be a plastic film, but also a lacquer layer or a similar layer, which is spread onto the printed wiring board 1 and the components 12 before the printed wiring board is moulded. The protective layer can be made of any material that can be fitted accurately around the components 12. The protective layer can naturally be utilized in both single- layer and multilayer printed boards. In some embodiments, the protective layer can be removed from the printed wiring board after the moulding, in other em- bodiments it is left in its place. [0060] Figure 6 shows a top view of a sixth printed wiring board of the invention schematically, and Figure 7 schematically shows a side view of the same printed wiring board in cross-section and fixed to an electronic device. [0061] The printed wiring board 1 shown in Figures 6 and 7 is a multilayer printed board, of which only the circuit pattern 3 and the support pattern 6 of the topmost layer can be seen. The lower circuit patters are suitably connected with the circuit pattern 3 of the topmost layer, and the support patterns are staggered with each other. [0062] The printed wiring board 1 shown in Figure 6 is planar and the components belonging thereto have not yet been arranged thereon. In the printed wiring board 1 , the circuit pattern area 9 is provided with a circuit pattern 3, which is manufactured according to the electrical purpose of the printed wiring board 1. [0063] The support pattern 6 is composed of basic lines 7 arranged crosswise at regular distances and edge lines 8 bordering the circuit pattern area 9. The support pattern 6 is made from the same material layer as the circuit pattern 3, and the material thereof is copper or a copper mixture, for instance, but any other circuit pattern material known per se can also be used. [0064] Before being arranged in its place in the electronic device 15, a part 16 following the shape of a spherical surface is provided in the printed wiring board 1 , and it is also otherwise preshaped to have a shape allowing it to be arranged in its place in the electronic device 15. Preshaping is carried out at elevated temperature under pressure or by means of a mould, whereby the printed wiring board 1 is moulded into a required shape. Preshaping can be performed before the components are mounted on the printed wiring board or after it. [0065] The shaping of the printed wiring board 1 into a three- dimensional shape can be carried out by methods based on shaping or mould moulding methods known per se and using under- or overpressure. Thus, the matter is not discussed in greater detail in this context. [0066] The support pattern 6 improves the malleability of the printed wiring board 1 by increasing the mechanical toughness of the printed wiring board 1 in a suitable manner, which was already planned in the design phase of the printed wiring board 1. [0067] After the premoulding the printed wiring board 1 is arranged in its place in the electronic device 15. The electronic device 15 can be, for instance, a mobile terminal or its accessory, a sensor, a dosing feeder or inhaler used for medical purposes, or another electronic device known per se. [0068] In another embodiment of the invention, the printed wiring board 1 is formed into a part of the outer casing of an electronic device. The printed wiring board 1 can also be attached to the outer casing by methods described in connection with Figure 5, for instance. In these embodiments, air space remaining between the printed wiring board 1 and the device casing, which is useless space as such, can be eliminated. [0069] The electronic device 15 is provided with fastening parts, at which the printed wiring board 1 is arranged. In this case, special attention must be paid on a tapered part 17 provided in the printed wiring board 1. A casing part 18 of the electronic device shown in Figure 7 is provided with special fastening means 19, which make the printed wiring board 1 to bend about 90° at the tapered part 17 when the printed wiring board 1 is arranged in the electronic device 15. Due to the bent printed wiring board, the end of the device 15 can be provided with a push button to direct the force pressing the button perpendicularly against the printed wiring board 1 , whereby stress caused by the forces in the direction of the printed wiring board can be avoided. The support pattern 6 modifies the properties of the printed wiring board 1 in the tapered part 17 suitably so that on the one hand, the printed wiring board 1 is easy to bend into a required shape at room temperature and, on the other hand, the printed wiring board 1 remains in its bent shape and does not tend to straighten. [0070] The structure of the printed wiring board 1 can also be sub- stantially stiff and unbendable at room temperature. Such a printed wiring board can be applied as a part of a mechanical support structure of an electronic device. In addition, a fairly thin but flexible printed wiring board can be made quite stiff by suitably moulding it into a three-dimensional shape. [0071] The drawings and the related description are only intended to illustrate the idea of the invention. In its details, the invention may vary within the scope of the claims.

Claims

CLAIMS 1. A printed wiring board comprising an insulating layer (2, 2a, 2b) and a circuit pattern (3, 3a, 3b) arranged on at least one surface of the insulating layer (2, 2a, 2b) and made of a conductive material, characterized in that at least one surface of the insulating layer (2, 2a, 2b) is provided with a support pattern (6, 6a, 6b), which comprises material lines (7, 7a, 7b) arranged at a distance from each other.

2. A printed wiring board as claimed in claim 1, characterized in that the support pattern (6, 6a, 6b) is made of the same material as the circuit pattern (3, 3a, 3b) on the same surface of the insulating layer (2, 2a, 2b).

3. A printed wiring board as claimed in claim 1 or 2, characterized in that the support pattern (6, 6a, 6b) is formed of the same conductive layer as the circuit pattern (3, 3a, 3b) on the same surface of the insulating layer (2, 2a, 2b).

4. A printed wiring board as claimed in claim 1, characterized in that the support pattern (6, 6a, 6b) is made of a different material than the circuit pattern (3, 3a, 3b) on the same surface of the insulating layer (2,2a, 2b).

5. A printed wiring board as claimed in any one of the preceding claims, characterized in that the support pattern (6, 6a, 6b) is arranged to cover substantially entirely the part of the surface of the printed wiring board (1 ) that does not comprise the circuit pattern (3, 3a, 3b) on said surface.

6. A printed wiring board as claimed in any one of the preceding claims, characterized in that the basic shape of the support pattern (6,

6a, 6b) is similar throughout the entire support pattern (6, 6a, 6b).

7. A printed wiring board as claimed in any one of claims 1 to 5, characterized in that the support pattern (6, 6a, 6b) comprises partial patterns (11a, 11b) differing from each other.

8. A printed wiring board as claimed in any one of the preceding claims, characterized in that the support pattern (6, 6a, 6b) comprises intersecting material lines (7, 7a, 7b).

9. A printed wiring board as claimed in any one of the preceding claims, characterized in that it is shaped into a three-dimensional shape.

10. A printed wiring board as claimed in any one of the preceding claims, characterized in that at least one insulating layer (2, 2a, 2b) comprises thermoplastic.

11. A printed wiring board as claimed in claim 10, character- ized in that said insulating layer (2, 2a, 2b) comprises polyolefin.

12. A printed wiring board as claimed in any one of the preceding claims, characterized in that at least one insulating layer (2, 2a, 2b) comprises elastomeric material.

13. A printed wiring board as claimed in any one of the preceding claims, characterized in that the support pattern (6, 6a, 6b) comprises copper.

14. A printed wiring board as claimed in any one of the preceding claims, characterized in that it has a substantially stiff and unbendable structure at room temperature.

15. A printed wiring board as claimed in any one of the preceding claims, characterized in that the support pattern (6, 6a, 6b) is arranged to act as a ground plane of the printed wiring board (1 ).

16. A printed wiring board as claimed in any one of claims 1 to 14, characterized in that the support pattern (6, 6a, 6b) is arranged to transmit the operating voltage

17. A printed wiring board as claimed in any one of the preceding claims, characterized in that it is a multilayer printed board comprising several insulating layers (2, 2a, 2b) and a support pattern (6, 6a, 6b) on the surface of at least one insulating layer (2, 2a, 2b).

18. A printed wiring board as claimed in claim 17, characterized in that the support pattern (6, 6a, 6b) is arranged on the surface of several insulating layers (2, 2a, 2b).

19. A printed wiring board as claimed in claim 18, characterized in that the support pattern (6, 6a, 6b) is arranged on the surface of each insulating layer (2, 2a, 2b).

20. A printed wiring board as claimed in claim 18 or 19, character i z e d in that at least some of the material lines (7, 7a, 7b) of the support patterns (6, 6a, 6b) arranged on the different surfaces are arranged to be staggered with each other.

21. A printed wiring board as claimed in any one of the preceding claims, characterized in that the support pattern (6, 6a, 6b) comprises an edge line (8) following the shape of the circuit pattern (3, 3a, 3b).

22. An electronic device comprising at least one printed wiring board (1), which comprises an insulating layer (2, 2a, 2b) and a circuit pattern (3, 3a,

3b) arranged on at least one surface of the insulating layer (2, 2a, 2b) and made of a conductive material, characterized in that at least one surface of the insulating layer (2, 2a, 2b) is provided with a support pattern (6, 6a, 6b), which comprises material lines (7, 7a, 7b) arranged at a distance from each other.

23. An electronic device as claimed in claim 22, characterized in that the support pattern (6, 6a, 6b) is made of the same material as the circuit pattern (3, 3a, 3b) on the same surface of the insulating layer (2, 2a, 2b).

24. An electronic device as claimed in claim 22, characterized in that the support pattern (6, 6a, 6b) is made of a different material than the circuit pattern (3, 3a, 3b) on the same surface of the insulating layer (2, 2a, 2b).

25. An electronic device as claimed in claim 22 or 23, c h a r a c - t e r i z e d in that the support pattern (6, 6a, 6b) is formed of the same conductive layer as the circuit pattern (3, 3a, 3b) on the same surface of the insulating layer (2, 2a, 2b).

26. An electronic device as claimed in any one of claims 22 to 25, characterized in that the support pattern (6, 6a, 6b) is arranged to cover substantially entirely the part of the surface of the printed wiring board (1) that does not comprise the circuit pattern (3, 3a, 3b) on said surface.

27. An electronic device as claimed in any one of claims 22 to 26, characterized in that the support pattern (6, 6a, 6b) comprises intersecting material lines (7, 7a, 7b).

28. An electronic device as claimed in any one of claims 22 to 27, characterized in that the printed wiring board (1) is shaped into a three-dimensional shape.

29. An electronic device as claimed in any one of claims 22 to 28, characterized in that the printed wiring board (1 ) is a multilayer printed board comprising several insulating layers (2, 2a, 2b) and a support pattern (6,

6a, 6b) on the surface of at least one insulating layer (2, 2a, 2b).

30. An electronic device as claimed in claim 29, characterized in that the support pattern (6, 6a, 6b) is arranged on the surface of several insulating layers (2, 2a, 2b).

31. An electronic device as claimed in claim 29, character- i z e d in that the support pattern (6, 6a, 6b) is arranged on the surface of each insulating layer (2, 2a, 2b).

32. An electronic device as claimed in claim 30 or 31 , c h a r a c - t e r i z e d in that at least some of the material lines (7, 7a, 7b) of the support patterns (6, 6a, 6b) arranged on the different surfaces are arranged to be stag- gered with each other.

33. An electronic device as claimed in any one of claims 22 to 32, characterized in that it comprises fastening means (19) and that the printed wiring board (1) is arranged at said fastening means (19) so that the printed wiring board (1) has a three-dimensional shape.

34. An electronic device as claimed in any one of claims 22 to 32, characterized in that it is a mobile terminal or its accessory.

35. A method for manufacturing a printed wiring board, in which method a circuit pattern (3, 3a, 3b) is arranged on at least one surface of an insulating layer (2, 2a, 2b), characterized by providing at least one sur- face of the insulating layer (2, 2a, 2b) with a support pattern (6, 6a, 6b), which comprises material lines (7, 7a, 7b) arranged at a distance from each other.

36. A method as claimed in claim 35, characterized by making the support pattern (6, 6a, 6b) of the same material as the circuit pattern (3, 3a, 3b).

37. A method as claimed in claim 35 or 36, c h a r a c t e r i z e d by shaping the printed wiring board (1) into a three-dimensional shape.

38. A method as claimed in claim 37, characterized by shaping the printed wiring board (1) before piling components (12) onto the printed wiring board (1).

39. A method as claimed in claim 37, characterized by shaping the printed wiring board (1) after the piling of the components (12).

40. A method as claimed in claim 39, c h a r a c t e r i z e d by arranging onto the components (12) a protective layer, which is arranged to support the components (12) during the shaping.

41. A method as claimed in claim 40, characterized in that the protective layer is a lacquer layer.

42. A method as claimed in claim 40, characterized in that the protective layer is a plastic film (13).

43. A method as claimed in claim 42, characterized in that the plastic film (13) comprises holes (14) extending through it. i 44. A method as claimed in any one of claims 39 to 43, c h a r a c - t e r i z e d by arranging the printed wiring board (1 ) into a mould and moulding it to bond to the plastic to be mould in said mould. 45. A method as claimed in claim 44, characterized in that the mould is an injection mould.