WO2010052627A1

WO2010052627A1 - Electronic textile

Info

Publication number: WO2010052627A1
Application number: PCT/IB2009/054844
Authority: WO
Inventors: Rabin Bhattacharya; Koen Van Os
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2008-11-06
Filing date: 2009-11-02
Publication date: 2010-05-14

Abstract

The invention relates to an electronic textile comprising a textile and an electronic component, wherein the textile comprises a designated position for mounting the electronic component such that the electronic component can be electrically addressed via the textile. The textile further comprises a first region completely overlapping the designated position, and abutted by a second region, wherein the first region has a higher stiffness than the second region. As a result, the electronic textile can be manufactured in a more reliable way. Furthermore, the first region may have a predetermined shape to enhance the functionality of the textile in the electronic textile.

Description

Electronic textile

FIELD OF THE INVENTION

The invention relates to a textile for mounting an electronic component at a designated position on the textile.

The invention further relates to a method for manufacturing such a textile, and to an electronic textile comprising such a textile.

BACKGROUND OF THE INVENTION

A textile is a material comprised of a network of fibers that can for instance be manufactured by weaving, knitting, crocheting, knotting, or pressing fibers together. For this purpose, interlocked fibers known as yarns or threads may be used.

Many types of textiles are used in our everyday life. When electronic components (i.e. devices that work by controlling the flow of electrons) are integrated into a textile new application fields emerge. When the textile is an integral part of the electrical circuit comprising the electronic components, an electronic textile is obtained. An example of an electronic component is a LED package in the form of a surface mounted device (SMD-LED), which can be attached to a textile substrate by gluing, soldering, snap button connection or stitching. The resulting light-emitting textile could open up a wide range of new interior and apparel applications, ranging from illumination to atmosphere creation to messaging. An electronic textile is known from UK patent application GB2396252A. The known electronic textile comprises SMD-LED 's which are mounted at designated positions on a textile either by hand or by using conventional equipment known from the electronics assembly industry. The SMD-LED's are electrically addressable via conductive tracks, which are either formed from yarns woven into the textile, or from tracks printed onto the textile.

SUMMARY OF THE INVENTION

A problem of the known electronic textile is that it is difficult to accurately mount electronic components to the textile. This is due to the fact that the textile is flexible enough to change shape when pressure or stress is applied to it, which is common in component mounting and roll-to-roll processing.

It is an object of the invention to provide a textile that can be used for manufacturing an electronic textile in a more reliable way. It is a further object of the invention to provide a method for manufacturing the textile.

It is a further object of the invention to provide an electronic textile comprising the textile.

According to a first aspect of the invention the object is realized by a textile for mounting an electronic component at a designated position on the textile, comprising a first region completely overlapping the designated position, and a second region abutting the first region, characterized in that the first region has a higher stiffness than the second region. In other words, the textile according to the invention is locally stiffened at the designated position, to allow for easier mounting of the electronic component. Preferably, the stiffness of the first region is at least twice as high as the stiffness of the second region.

In a first embodiment of the textile according to the invention, the textile is a woven textile, and the first region has a tighter weave than the second region. This embodiment, wherein the tighter weave causes the first region to have a higher stiffness than the second region, can be conveniently manufactured by subjecting a woven textile to a local thermal treatment.

In a second embodiment of the textile according to the invention, the first region has a predetermined shape. This embodiment enhances the functionality of the textile, for example when the predetermined shape is arranged to act as a heat sink, as a receptacle for the electronic component, or as a light-modifying element. According to a second aspect of the invention the object is realized by a method for manufacturing a textile for mounting an electronic component at a designated position on the textile, the textile comprising a first region completely overlapping the designated position, and a second region abutting the first region, wherein the first region has a higher stiffness than the second region, the method comprising a step wherein the first region is formed by subjecting an area of the textile to a thermal treatment.

In an embodiment of this method, the thermal treatment is performed using a heat press, and the method further comprises a step wherein the first region is molded into a predetermined shape by the heat press. The method according to this embodiment uses a single step to create the stiffened first region, and to mold it into a predetermined shape that can enhance the functionality of the textile.

According to a third aspect of the invention the object is realized by a method for manufacturing a textile for mounting an electronic component at a designated position on the textile, the textile comprising a first region completely overlapping the designated position, and a second region abutting the first region, wherein the first region has a higher stiffness than the second region, the method comprising a step wherein the first region is formed by treating an area of the textile with a stiffening agent.

According to a fourth aspect of the invention the object is realized by an electronic textile comprising an electronic component and a textile for mounting the electronic component at a designated position on the textile, the textile comprising a first region completely overlapping the designated position, and a second region abutting the first region, characterized in that the first region has a higher stiffness than the second region.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of the invention will now be described in detail with reference to the accompanying drawings, in which:

Fig. 1 shows an embodiment of a textile for mounting an electronic component at a designated position on the textile according to the invention; Figs. 2 A and 2B show embodiments of a method for manufacturing a textile according to the invention, both using a local thermal treatment;

Fig. 3 shows a further embodiment of a method for manufacturing a textile according to the invention, using a stiffening agent;

Fig. 4 shows a further embodiment of a textile according to the invention, wherein the first region has a predetermined shape;

Fig. 5 shows an embodiment of an electronic textile according to the invention, wherein the first region has a predetermined shape that is arranged to act as a receptacle for an electronic component, and as a light-modifying element;

Fig. 6 shows a further embodiment of an electronic textile according to the invention, wherein the first region has a predetermined shape that is arranged to act as a heat sink;

Fig. 7 shows a further embodiment of an electronic textile according to the invention, comprising an assembly of electronic textiles as shown in Fig. 6. It should be noted that these figures are diagrammatic and not drawn to scale. For the sake of clarity and convenience, relative dimensions and proportions of parts of these figures have been shown exaggerated or reduced in size.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following description, the present invention is described with reference to exemplary textiles according to the invention.

Fig. 1 shows the textile 10 comprising the designated position 11, at which an electronic component is to be mounted on the textile 10. The designated position 11 is shown here as a square, but it can have any given shape. A designated position is a position on a textile where an electronic component is to be provided, taking into account the available tolerance in connecting the electronic component to the textile. In other words, a designated position defines an area on a textile in which an electronic component must be placed in order to be electrically addressable via the textile. The designated position 11 is completely overlapped by the first region 12. In other words, the designated position 11 is entirely located within the first region 12. The first region 12 is shown here as a circle, but it can have any given shape.

The first region 12 is abutted by the second region 13. In fact, in the textile 10, the first region 12 is abutted on all sides by the second region. In other words, in the textile 10 the second region 13 fully encloses the first region 12, without overlapping the first region

12. Similarly as for the designated position 11 and the first region 12, the second region 13 can have any given shape.

For the purpose of the invention, a first region does not have to be fully enclosed by a second region, as the first region may also be located on a textile such that it shares an edge with the textile. Furthermore, a textile may comprise more than one designated position, in order to be able to accommodate more than one electronic component.

In that case, each designated position will be completely overlapped by a first region that is abutted by a second region.

The textile 10 comprises yarns interwoven in warp and weft directions (not shown in Fig. 1). In weaving, yarns with a general extension in the direction of weaving are commonly referred to as warp yarns, while yarns that extend substantially perpendicularly to the weaving direction (and to the warp yarns) are referred to as weft yarns. However, for the purpose of the invention, the textile does not necessarily have to be a woven textile, but it can also be a textile obtained by knitting, crocheting, knotting, or pressing fibers together. In the textile 10 of Fig. 1, the first region 12 has a higher stiffness than the second region 13. In the context of this invention, stiffness is a property of an elastic solid body, and represents the resistance of the body to deflection by an applied force. In other words, the stiffness of an elastic solid body is the resistance offered by the body to bending, which can be expressed as the ratio of the applied force and the deflected distance, and which is typically measured in Newtons per meter (N/m). This means that the stiffness of a textile can be measured by (i) fixing the textile in a clamp, (ii) pushing on the textile with a known force, and (iii) measuring the distance by which the textile is deflected under the application of the known force. In the textile 10 of Fig. 1, the first region 12 has a stiffness that is at least twice the stiffness of the second region 13. Preferably, the first region 12 has a stiffness that is at least four times the stiffness of the second region 13.

The relative areas of the first region 12 and the second region 13 are chosen such as to maintain sufficient flexibility of the textile 10 as a whole.

The first region 12 can have a higher stiffness due to the yarns comprised in the textile 10 having a locally increased Young's modulus. The Young's modulus (sometimes also referred to as modulus of elasticity, elastic modulus, or tensile modulus) is a measure of the stiffness of an elastic material, and it is defined as the ratio of stress over strain. The Young's modulus can be experimentally determined from the slope of a stress-strain curve created during tensile tests conducted on a sample of the material, and it is typically expressed in gigapascals (GPa). The stiffness of a solid body is given by the Young's modulus, multiplied by the ratio of the cross-sectional area and the length of the solid body. Approximate values for the Young's modulus of common synthetic fibers are 2-3 GPa for polyethylene terephthalate, 2.5 GPa for polyimide, and 3-7 GPa for Nylon. This means that a polyimide fiber with a diameter of 1 mm and a length of 2 cm, has a stiffness of approximately 10⁵ N/m.

However, as stiffness is a property of a solid body, while the Young's modulus is a property of the constituent material of the body, the increased stiffness of the first region 12 may also have a different origin, such as a local longitudinal compression of the yarns, a locally tighter weave, or a combination thereof. With a local longitudinal compression of the yarns it is meant that in the first region 12 the yarns have been compressed (or shrunken) along their length, as compared to the yarns in the second region 13. With a locally tighter weave it is meant that in the first region 12 the weave has a higher density than in the second region 13. In other words, in the first region 12 the yarns are closer together than in the second region 13.

A locally tighter weave may result in an increase of the frictional forces between the yarns, which in turn results in an increased stiffness. A locally tighter weave may also result in a locally increased tension, which in turn could induce a deformation of the stiffened region.

A local longitudinal compression of the yarns and/or a locally tighter weave can be obtained by subjecting a textile to a local thermal treatment, for instance by using laser irradiation or a heat press to heat, and partially melt, the textile.

A method wherein a textile is subjected to a local thermal treatment by using laser irradiation is shown in Fig. 2A, wherein an area of the textile 210 comprising the designated position 211 is irradiated by the laser 214 to create the first region 212. In this example, the second region 213 is the remainder of the textile 210, so that the first region 212 and the second region 213 together constitute the textile 210.

A method wherein a textile is subjected to a local thermal treatment by using a heat press is shown in Fig. 2B. In step (a), the heat press 224 is positioned in a starting position relative to the textile 220. In step (b), the heat press 224 is pressed into the textile 220, to create the shaped region 221 in the textile 220. In step (c), heat 225 is provided to the shaped region 221. In step (d), heat transfer is stopped, and the first region 222 is formed, having a higher stiffness than the abutting second region 223. For the sake of clarity, it is not shown in Fig. 2B that the first region 222 comprises a designated position for mounting an electronic component on the textile 220. In step (e), the heat press 224 is returned to its starting position, and the first region 222 retains a predetermined shape. A stiffened first region may also be obtained by using a stiffening agent that can, for instance, be locally applied in liquid form by a printing technique. This is schematically shown in Fig. 3, wherein the printer 34 provides an area of the textile 30 comprising the designated position 31 with the liquid stiffening agent 35 to create the first region 32. Again, the second region 33 is the remainder of the textile 30, so that the first region 32 and the second region 33 together constitute the textile 30. An example of a suitable stiffening agent is starch.

Fig. 4 shows a cross section of the textile 40, comprising the designated position 41, the first region 42 completely overlapping the designated position 41, and the second region 43 abutting the first region 42. In the textile 40, the first region 42 has a predetermined shape with a semi-circular cross section, although any kind of shape may be used. The textile 40 can be manufactured by using a heat press, as illustrated in Fig. 2B. The predetermined shape may be such as to perform the function of a heat sink, a receptacle for an electronic component, or a light-modifying element. In the context of this invention, a heat sink is an object that absorbs and dissipates heat from another object (such as an electronic component) using either direct or radiant thermal contact. In other words, a heat sink is a cooling device. An example of a heat sink is an object that comprises cooling fins.

In the context of this invention, a receptacle is an object wherein an electronic component can be fitted so that the electronic component can be mounted and connected to a textile with improved accuracy and robustness. A light-modifying element can for instance be a diffuser or an absorber.

Fig. 5 shows the electronic textile 500, comprising the textile 501 and the light-emitting element 508. In Fig. 5(a), the textile 501 and the light-emitting element 508 are shown separately. The textile 501 is a textile strip of which, for the sake of clarity, only a part is shown in Fig. 5.

The textile 501 comprises the designated position 502, the first region 503 completely overlapping the designated position 502, and the second region 504 abutting the first region 503. In reality, the area of the second region 504 relative to the area of the first region 503 will be such as to maintain sufficient flexibility of the textile strip 501. Also, the textile strip 501 comprises further designated positions for mounting electronic components, each of which is completely overlapped by a first region that is abutted by a second region.

The textile 501 further comprises the first textile electrode 505 and the second textile electrode 506, both being electrically conductive yarns that are woven into the textile 601.

The light-emitting element 508 comprises the first component electrode 509 and the second component electrode 510, that have to be electrically connected to the first textile electrode 505 and the second textile electrode 506, respectively, so that in the electronic textile 500 the light-emitting element 508 is electrically addressable via the textile 501. In that respect, it is clear that the designated position 502 is a position on the textile 501 where the light-emitting element 508 is to be provided.

In Fig. 5(b), the first region 503 is shaped into the receptacle 507 for the light- emitting element 508. In Fig. 5(c), the light-emitting element 508 has been mounted into the receptacle 507. Furthermore, the first component electrode 509 and the second component electrode 510 have been electrically connected to the first textile electrode 505 and the second textile electrode 506, respectively, resulting in the electronic textile 500 to be formed. The light-emitting element 508 is arranged to emit light 511. In the electronic textile 500, the light-emitting element 508 is mounted into the receptacle 507 in such a way that the light 511 is directed towards an inner wall of the receptacle 507. As the optical properties of the first region 503 are such as to allow the passage of the modified light 512, next to being the receptacle 507 the first region 503 is also arranged to act as the light- modifying element 513, for example by diffusing the light 511, or by absorbing part of the light 511.

Fig. 6 shows the electronic textile 600, comprising the textile 601 and the electronic component 608.

In Fig 6(a), the textile 601 is shown. The textile 601 is a textile strip of which, for the sake of clarity, only a part is shown in Fig. 6.

The textile 601 comprises the designated position 602, the first region 603 completely overlapping the designated position 602, and the second region 604 abutting the first region 603. In reality, the area of the second region 604 relative to the area of the first region 603 will be such as to maintain sufficient flexibility of the textile strip 601. Also, the textile strip 601 comprises further designated positions for mounting electronic components, each of which is completely overlapped by a first region that is abutted by a second region.

The textile 601 further comprises the first textile electrode 605 and the second textile electrode 606, both being electrically conductive yarns that are woven into the textile 601. In Fig. 6(b), the first region 603 is shaped into the predetermined shape 607 that has the form of a V-shaped groove.

In Fig. 6(c), the electronic component 608 has been mounted on the textile 601, to bridge the predetermined shape 607. Furthermore, the electronic component has been electrically connected to the first textile electrode 605 and the second textile electrode 606, respectively, resulting in the electronic textile 600 to be formed.

In operation, the electronic component 608 generates heat that can be dissipated by the predetermined shape 607. In this respect, the predetermined shape 607 is a heat sink that is arranged to operate in a manner similar to a cooling fin. For instance, heat generated by the electronic component 608 can be dissipated through the volume of air enclosed by the predetermined shape 607 and the electronic component 608, and/or as a result of the increased surface area of the textile 601 at the location of the electronic component 608. Concerning the latter, the first textile electrode 605 and the second textile electrode 606 that are comprised in the textile 601 and that at least partly run through the predetermined shape 601 may assist in dissipating heat from the electronic component 608. The predetermined shape 607 may also be provided with a coating that has heat dissipative properties. The skilled person will understand that for a predetermined shape to be able to function as a heat sink in a manner as described above, it does not necessarily has to be in the form of a groove, let alone a V-shaped groove. Other predetermined shapes, such as a cup or a U-shaped groove, will also function.

Fig. 7 shows the electronic textile 700, comprising the textile strips 710, 720, 730, 740, 750, and 760, each of which is similar to the textile strip 601, of which a part is shown in Fig. 6.

In the electronic textile 700, the textile strips 710-760 may be interconnected in a variety of ways, for instance by a coupling textile on which each of the textile strips 710- 760 has been fastened.

The electronic textile 700 represents a 6-by-6 matrix of electronic components (for example, light-emitting elements), each of which is mounted at a designated position on a textile strip, each designated position being completely overlapped by a region of the textile strip having a higher stiffness than the abutting regions of the textile strip, and having a predetermined shape that is arranged to act as a heat sink for the electronic component.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. A textile (10,501) for mounting an electronic component (508) at a designated position (11,502) on the textile (10,501), comprising: a first region (12,503) completely overlapping the designated position (11,502), and - a second region (13,504) abutting the first region (12,503), characterized in that the first region (12,503) has a higher stiffness than the second region (13,504).

2. The textile (10) according to claim 1, wherein the stiffness of the first region (12) is at least twice as high as the stiffness of the second region (13).

3. The textile (10) according to claim 1 or 2, wherein the textile (10) is a woven textile, and wherein the first region (12) has a tighter weave than the second region (13).

4. The textile (40) according to any of claims 1 to 3, wherein the first region (42) has a predetermined shape (44).

5. The textile (40,601) according to claim 4, wherein the predetermined shape (44) is arranged to act as a heat sink (607).

6. The textile (40,501) according to claim 4, wherein the predetermined shape (44) is arranged to act as a receptacle (507) for the electronic component (508).

7. The textile (40,501) according to claim 4, wherein the predetermined shape (44) is arranged to act as a light-modifying element (513).

8. An electronic textile (500) comprising the textile (501) according to any of claims 1 to 7, and the electronic component (508).

9. A method for manufacturing the textile (210,220) according to claim 1, comprising a step wherein the first region (212,222) is formed by subjecting an area of the textile (210,220) to a thermal treatment.

10. The method according to claim 9, wherein the thermal treatment is performed using a heat press (224), the method further comprising a step wherein the first region (222) is molded into a predetermined shape by the heat press (224).

11. A method for manufacturing the textile (30) according to claim 1 , comprising a step wherein the first region (32) is formed by treating an area of the textile (20) with a stiffening agent (35).