Patent Description:
Since a substrate made of a ceramic has superior insulating properties, superior thermal conductivity, and the like, the substrate may be utilized as a substrate for a lighting device such as an on-board lamp.

The lighting device includes a substrate in which a light emitting element such as a light emitting diode and a wiring or the like are located, and a socket for accommodating the substrate.

Here, Patent Document <NUM> discloses a socket including a notch at a location where a corner portion of a substrate is located.

<CIT> discloses a lamp apparatus comprising: a body having thermal conductivity, and is provided with a base unit, a cylindrical portion extending upright in a substantially cylindrical shape from the back side of the base unit, and a plurality of thermal radiation fins formed on the back side of the base unit; a light-emitting module disposed on the front side of the base unit of the body; a lighting device configured to perform lighting control on the light-emitting element and disposed inside the cylindrical portion of the body; a cap unit including a pair of electrode pins and configured to cover the lighting device; and an insulating member disposed inside the cylindrical portion of the body and including an upright portion extending upright from a peripheral edge thereof.

However, in the conventional technology described above, since the corner portion of the substrate is exposed, for example, when receiving an impact from outside, chips and cracks may occur in the corner portion of the substrate.

The present invention has been made in view of the above, and an object thereof is to provide an electronic device which can suppress damage to the corner portion of the substrate while using a housing part in which the corner portion of the substrate is exposed.

The present invention provides a lighting device according to claim <NUM>. Further embodiments of the present invention are disclosed in the dependent claims.

According to the present invention, damage to a corner portion of a substrate can be suppressed while using a socket in which the corner portion of the substrate is exposed.

Modes (hereinafter, referred to as "embodiments") for implementing a lighting device according to the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below are not intended to limit the lighting device according to the present invention.

Each of the embodiments can be appropriately combined within a range in which the processing contents do not contradict each other. In each of the embodiments below, the same reference numerals are assigned to the same portions, and redundant descriptions thereof will be omitted.

In the embodiments described below, expressions such as "constant", "orthogonal", "vertical," and "parallel" may be used, but these expressions do not need to be exactly "constant", "orthogonal", "vertical," and "parallel". In other words, each of the above-described expressions allows for deviations in, for example, manufacturing accuracy, positioning accuracy, and the like.

In each of the drawings referred below, for ease of explanation, an X-axis direction, a Y-axis direction, and a Z-axis direction that are orthogonal to each other may be defined to illustrate an orthogonal coordinate system in which the Z-axis positive direction is the vertically upward direction.

First, a configuration of the lighting device <NUM> that does not fall under the scope of the invention will be described with reference to <FIG>. <FIG> is a schematic side view illustrating the lighting device according to the embodiment. <FIG> is a schematic perspective view of a socket according to the embodiment. <FIG> is a schematic plan view of a substrate according to the embodiment.

As illustrated in <FIG>, a lighting device <NUM> according to the embodiment includes a substrate <NUM> made of a ceramic, a socket <NUM> for accommodating the substrate <NUM>, and a plurality of electrically conductive terminals <NUM> connected to the substrate <NUM>. The lighting device <NUM> is used, as, for example, an on-board lighting device. Specifically, the lighting device <NUM> is used as a light source such as a rear lamp, a turn lamp, a position lamp, and a fog lamp.

As illustrated in <FIG>, the socket <NUM> includes a housing part <NUM>, a flange part <NUM>, and a plurality of heat dissipating fins <NUM>.

The housing part <NUM> is, for example, a bottomed tubular portion having a substantially circular shape in a plan view, and is located on a surface opposite a surface on which the plurality of heat dissipating fins <NUM> are located in the flange part <NUM> described below. The housing part <NUM> includes a recessed portion <NUM> recessed from an end surface of the socket <NUM>, specifically from a surface opposite a surface in contact with the flange part <NUM> of the housing part <NUM>, toward the other end side of the socket <NUM>. The substrate <NUM> is accommodated in the recessed portion <NUM>.

The recessed portion <NUM> includes a plurality of side wall portions <NUM>. The plurality of side wall portions <NUM> have, for example, an arcuate shape in a plan view, and are arranged along a circumferential direction around the substrate <NUM> so as to surround the substrate <NUM>.

Gaps <NUM> are provided each between two of the plurality of side wall portions <NUM> adjacent to each other in the circumferential direction.

The flange part <NUM> is, for example, a disc-shaped portion, and is located between the housing part <NUM> and the plurality of heat dissipating fins <NUM>. The flange part <NUM> has a larger diameter than that of the housing part <NUM>, and when the lighting device <NUM> is inserted into, for example, a mounting hole provided in the vehicle body, the flange part <NUM> comes into contact with a peripheral edge of the mounting hole. A bayonet (not illustrated) for a twist lock is located on an outer peripheral surface of the housing part <NUM>, and by rotating the socket <NUM> in a state where the flange part <NUM> is in contact with the peripheral edge of the mounting hole, the bayonet is fitted into a groove on the vehicle body side, so that the lighting device <NUM> is in a state of being fixed to the vehicle body.

The plurality of heat dissipating fins <NUM> are located on a surface opposite a surface on which the housing part <NUM> is located in the flange part <NUM>. Heat generated in the substrate <NUM> is emitted primarily from the plurality of heat dissipating fins <NUM>. Here, the example is given in which the socket <NUM> includes four heat dissipating fins <NUM>, but the number of the heat dissipating fins <NUM> of the socket <NUM> is not limited to four.

Note that a heat transfer member (not illustrated) formed of, for example, a metal such as aluminum is located between a bottom portion of the recessed portion <NUM> and the substrate <NUM>. The heat transfer member is located so as to be in contact with the substrate <NUM> and the bottom portion of the recessed portion <NUM>, and transmits the heat generated in the substrate <NUM> to the heat dissipating fins <NUM>.

As illustrated in <FIG>, the substrate <NUM> is a member having a flat plate shape, and including a circuit forming surface <NUM> (here, a front surface) serving as a first surface, a second surface (here, a rear surface) located opposite the circuit forming surface <NUM>, and a third surface (here, a side surface) connected to each of the circuit forming surface <NUM> and the second surface. The substrate <NUM> is accommodated in the housing part <NUM> in a state where the second surface faces the bottom surface of the recessed portion <NUM>, in other words, in a state where the circuit forming surface <NUM> faces the front.

Examples of the ceramic used for the substrate <NUM> include an aluminum oxide-based ceramic, a zirconium oxide-based ceramic, a composite ceramic of aluminum oxide and zirconium oxide, a silicon nitride-based ceramic, an aluminum nitride-based ceramic, a silicon carbide-based ceramic, and a mullite ceramic. Note that the substrate <NUM> made of the aluminum oxide-based ceramic has mechanical strength required for the substrate <NUM>, and has superior workability. The substrate <NUM> made of the aluminum nitride-based ceramic has high thermal conductivity, and thus has superior heat radiating properties.

Wirings <NUM> containing a metal such as copper, silver, or the like as a main constituent are located on the circuit forming surface <NUM>. The wirings <NUM> are electrically connected to electrically conductive terminals <NUM> via an electrically conductive bonding material (not illustrated) such as a brazing material or a solder.

A light emitting element <NUM> is located on the wirings <NUM>. The light emitting element <NUM> is, for example, a light emitting diode (LED), a laser diode (LD), or the like.

Note that the shape and the arrangement of the wirings <NUM> and the light emitting element <NUM> are illustrated as an example in <FIG>. For example, in <FIG>, the example is illustrated in which the light emitting element <NUM> located on one of the wirings <NUM> and the other one of wirings <NUM> are electrically connected by a bonding wire <NUM>, but a method of connecting the wiring <NUM> and the light emitting element <NUM> is not limited to the example illustrated in <FIG>. Although not illustrated here, other than the wirings <NUM> and the light emitting element <NUM>, a resistor or the like is located on the circuit forming surface <NUM>.

As illustrated in <FIG>, the circuit forming surface <NUM> of the substrate <NUM> includes four sides <NUM> and four corner portions <NUM>. The four sides <NUM> include two first sides 111a parallel to each other and two second sides 111b parallel to each other. The two first sides 111a extend along the Y-axis direction, and the two second sides 111b extend along the X-axis direction. In other words, the first sides 111a and the second sides 111b are orthogonal to each other. Each of the four corner portions <NUM> is located between one of the first sides 111a and one of the second sides 111b. The two first sides 111a, the two second sides 111b, and the four corner portions <NUM> are continuous in the order of one of the first sides 111a, one of the corner portions <NUM>, one of the second sides 111b, one of the corner portions <NUM>, the other one of the first sides 111a, one of the corner portions <NUM>, the other one of the second sides 111b, and one of the corner portions <NUM>. The second surface of the substrate <NUM> has the same shape as the circuit forming surface <NUM>.

Next, a relationship between the plurality of side wall portions <NUM> provided in the socket <NUM> and the substrate <NUM> will be described with reference to <FIG> is a schematic plan view of a lighting device that does not fall under the scope of the invention.

Note that, in <FIG>, for ease of understanding, a part of a configuration of the socket <NUM> such as the flange part <NUM> is not illustrated.

As illustrated in <FIG>, the four side wall portions <NUM> of the socket <NUM> respectively face corresponding one of the four sides <NUM> of the circuit forming surface <NUM>. Specifically, each of first side wall portions 211a facing one of the first sides 111a extend in the Y-axis direction in the same manner as the first sides 111a, and is located outward in the X-axis direction of the corresponding one of the first sides 111a. Each of second side wall portions 211b facing one of the second sides 111b extends in the X-axis direction in the same manner as the second sides <NUM>11b, and is located outward in the Y-axis direction of the corresponding one of the first sides 111a.

In this way, since each of the side wall portions <NUM> is located in the socket <NUM> so as to face corresponding one of the sides <NUM> of the substrate <NUM>, each of sides <NUM> of the substrate <NUM> can be protected even when the lighting device <NUM> receives an external impact, for example. In the embodiment, since each of the side wall portions <NUM> is longer than the facing one of sides <NUM>, an end portion of the facing one of sides <NUM> can be reliably protected. More specifically, since both end portions of each of the side wall portions <NUM> in the extending direction are located outward in the extending direction than both end portions of the facing one of the sides <NUM>, the both end portions of the facing one of the sides <NUM> can be reliably protected, and thus reliability in the vibration environment of the lighting device <NUM> mounted on the vehicle can be improved.

By positioning each of the side wall portions <NUM> so as to face the corresponding one of the sides <NUM> of the substrate <NUM>, the heat generated in the substrate <NUM> can be dissipated from each of the sides <NUM> of the substrate <NUM> to the corresponding one of the side wall portions <NUM>.

On the other hand, as described above, each of the gaps <NUM> is located between side wall portions <NUM> adjacent to each other, that is, between one of the first side wall portions 211a and corresponding one of the second side wall portions 211b. The gaps <NUM> are provided, for example, so that the corner portions of the substrate do not interfere with the recessed portion due to the miniaturization of the socket. Further, the gaps <NUM> are provided, for example, to prevent the heat generated in the substrate from being kept in the recessed portion.

Each of the gaps <NUM> is located between one of the first side wall portions 211a facing one of the first sides 111a and one of the second side wall portions 211b facing one of the second sides 111b. Each of the corner portions <NUM> is located between corresponding one of the first sides 111a and corresponding one of the second sides <NUM>1b. Thus, when viewing the inside of the recessed portion <NUM> from the side of the lighting device <NUM> over the gaps <NUM>, each of the corner portions <NUM> of the substrate <NUM> is located at a location visible from corresponding one of the gaps <NUM>.

In this way, when the lighting device <NUM> is viewed from the side, the corner portions <NUM> of the substrate <NUM> are exposed from the recessed portion <NUM>. Thus, when the lighting device <NUM> receives the external impact, the corner portions <NUM> of the substrate <NUM> are considered to be more likely to be chipped or cracked by such an impact than the sides <NUM> of the substrate <NUM> protected by the side wall portions <NUM>.

On the other hand, as illustrated in <FIG>, the substrate <NUM> according to the embodiment includes the corner portions <NUM> having an inverted-R shape curved toward the inside of the circuit forming surface <NUM> in a plan view of the substrate <NUM> from a direction perpendicular to the circuit forming surface <NUM>.

The corner portions <NUM> having the inverted-R shape have a larger margin with respect to the gaps <NUM> than a case where the corner portions are not chamfered or the corner portions are chamfered into a C-plane shape. In other words, the corner portions <NUM> having the inverted-R shape are located at a position further away from the gaps <NUM> than the case where the corner portions are not chamfered or the case where the corner portions are chamfered into the C-plane shape. Thus, the corner portions <NUM> having the inverted-R shape are less likely to be damaged over the gaps <NUM>.

By configuring the corner portions <NUM> to have the inverted-R shape, the heat capacity of the entirety of the substrate <NUM> can be reduced as compared with the case where the corner portions are not chamfered or the case where the corner portions are chamfered into the C-plane shape. As a result, heat accumulation in the substrate <NUM> can be suppressed. By configuring the corner portions <NUM> to have the inverted-R shape, a surface area of the corner portions <NUM> can be increased as compared with the case where the corner portion is not chamfered or the case where the corner portion is chamfered in a C-plane shape. Accordingly, heat radiation from the corner portions <NUM> can be increased, and heat can be efficiently dissipated from the corner portions <NUM> to the exterior of the socket <NUM> via the gaps <NUM>.

Note that the shape of the corner portions <NUM> when viewing the substrate <NUM> from a direction perpendicular to the circuit forming surface <NUM> corresponds to, for example, one arc (quarter arc) obtained by equally dividing one circle into four. The substrate used in the lighting device may be formed by obtaining a large number of substrates from one single large substrate. The large substrate is provided with a plurality of slits in the longitudinal direction and the horizontal direction for splitting, and by providing through-holes having circular shape at positions where the slits in the longitudinal direction and the slits in the horizontal direction intersect with each other, each of the corner portions <NUM> having the inverted-R shape can be formed at four corner portions of each of the substrates <NUM> serving as individual pieces. In this way, configuring of the corner portions <NUM> in a quarter arc shape can enhance productivity in the case where the large number of substrates <NUM> is obtained from the one single large substrate can be improved. By configuring the through-holes in a circular shape, cracking due to stress concentration can be less likely to occur as compared with a case where through-holes having rectangular shape are used, for example.

Next, a modified example of the lighting device <NUM> according to the embodiments described above will be described below. First, the configuration example of a lighting device according to a first modified example will be described with reference to <FIG> is a schematic plan view of a lighting device according to the first modified example. <FIG> is a schematic enlarged view of a portion H in <FIG>. Note that, in <FIG>, for ease of understanding, a part of a configuration of the socket <NUM> such as the flange part <NUM>, and the wirings <NUM>, the light emitting element <NUM>, and the like on the substrate <NUM> are not illustrated.

As illustrated in <FIG>, in a lighting device 1A according to the first modified example, each of the electrically conductive terminals <NUM> is located in a recessed region of corresponding one of the corner portions <NUM>. Here, an example is given in which each one of the four electrically conductive terminals <NUM> included in the lighting device 1A is located in the recessed region of the corresponding one of the four corner portions <NUM>.

In this way, by positioning each of the electrically conductive terminals <NUM> in the recessed region of the corresponding one of the corner portions <NUM>, the circuit mounting region of the circuit forming surface <NUM> can be more widely ensured than a case where the electrically conductive terminals <NUM> are located on the circuit forming surface <NUM> of the substrate <NUM>.

As illustrated in <FIG>, in the lighting device 1A, the four side wall portions <NUM> and the four electrically conductive terminals <NUM> are alternately arranged along the circumferential direction. By alternately arranging the side wall portions <NUM> and the electrically conductive terminals <NUM>, since the heat generation points are dispersed as compared with a case where, for example, the plurality of electrically conductive terminals <NUM> are concentrated in one place, the thermal uniformity of the substrate <NUM> can be increased. Note that the lighting device 1A does not necessarily include the same number of electrically conductive terminals <NUM> as the number of the corner portions <NUM>. In other words, the side wall portions <NUM> and the electrically conductive terminals <NUM> may be alternately arranged at least in part in the circumferential direction.

As illustrated in <FIG>, the recessed region of each of the corner portions <NUM> corresponds to a region R1 surrounded by virtual extended lines <NUM> and <NUM> of one of the first sides 111a and one of the second sides 111b adjacent to one of the corner portions <NUM> and the one of the corner portions <NUM>. Here, an example is given in which each of the electrically conductive terminals <NUM> entirely fits in the region R1, but at least a portion of each of the electrically conductive terminals <NUM> may be located in the region R1. In other words, each of the electrically conductive terminals <NUM> may partially protrude from the region R1.

Next, a configuration example of a lighting device according to a second modified example will be described with reference to <FIG> is a schematic plan view of the lighting device according to the second modified example.

As illustrated in <FIG>, in a lighting device 1B according to the second modified example, similar to the lighting device 1A according to the first modified example, each of the electrically conductive terminals <NUM> is located in a recessed region of corresponding one of the corner portions <NUM>.

In the lighting device 1B according to the second modified example, for example, each of the first side wall portions 211a is longer than a line segment connecting intersection points <NUM> and <NUM> between a virtual extended line <NUM> of facing one of the first sides 111a and virtual extended lines <NUM> and <NUM> of two second sides 111b adjacent to the corresponding one of the first sides 111a via corresponding one of the corner portions <NUM>. The same applies to the second side wall portions 211b, and each of the second side wall portions 211b is longer than a line segment connecting intersection points <NUM> and <NUM> (one of them is not illustrated) between a virtual extended line <NUM> of facing one of the second sides 111b and virtual extended lines <NUM> and <NUM> (one of them is not illustrated) of two first sides 111a adjacent to the corresponding one of the second sides 111b via corresponding one of the corner portions <NUM>.

With such a configuration, substantially the entirety of each of the electrically conductive terminals <NUM> can be covered with two side wall portions <NUM> (one of the first side wall portions 211a and one of the second side wall portions 211b). As a result, the reliability in the vibration environment of the lighting device <NUM> mounted on the vehicle can be further improved.

Note that the side wall portions <NUM> may be configured to cover a portion of each of the electrically conductive terminals <NUM>. For example, each of the first side wall portions 211a may be shorter than the line segment connecting the intersection points <NUM> and <NUM> between the virtual extended line <NUM> of facing one of the first sides 111a and the virtual extended lines <NUM> and <NUM> of two second sides 111b adjacent to the corresponding one of the first sides 111a via corresponding one of the corner portions <NUM>. This corresponds to, for example, the configuration illustrated in <FIG>. Even with such a configuration, each of the electrically conductive terminals <NUM> can be protected by the two side wall portions <NUM> (one of the first side wall portions 211a and one of the second side wall portions 211b), and thus improving the reliability in the vibration environment of the lighting device <NUM>.

Next, a configuration of a lighting device according to a third modified example will be described with reference to <FIG> is a schematic plan view of the lighting device according to the third modified example. Note that the periphery of the corner portion <NUM> is illustrated enlarged in <FIG>.

As illustrated in <FIG>, in a lighting device 1C according to the third modified example, the electrically conductive terminal <NUM> is in contact with two side wall portions <NUM> adjacent to each other (the first side wall portion 211a and the second side wall portion 211b). In this way, by bringing the electrically conductive terminal <NUM> into contact with the side wall portions <NUM>, for example, the vibration of the electrically conductive terminal <NUM> can be suppressed by the side wall portions <NUM>. Accordingly, the reliability in the vibration environment of the lighting device <NUM> can be further improved. Further, when the electrically conductive terminal <NUM> generates heat, the heat generated at the electrically conductive terminal <NUM> can be efficiently dissipated to the side wall portions <NUM>.

Next, a configuration of a lighting device according to a fourth modified example will be described with reference to <FIG> is a schematic plan view of the lighting device according to the fourth modified example. Note that the periphery of the corner portion <NUM> is illustrated enlarged in <FIG>.

As illustrated in <FIG>, in a lighting device 1D according to the fourth modified example, the electrically conductive terminal <NUM> is sandwiched between two adjacent side wall portions <NUM> (the first side wall portion 211a and the second side wall portion 211b).

In this way, by sandwiching the electrically conductive terminal <NUM> between the two side wall portions <NUM>, similar to the lighting device 1C according to the third modified example, the vibration of the electrically conductive terminal <NUM> can be suppressed by the side wall portions <NUM>. Further, when the electrically conductive terminal <NUM> generates heat, the heat generated at the electrically conductive terminal <NUM> can be efficiently dissipated to the side wall portions <NUM>.

By sandwiching the electrically conductive terminal <NUM> between the two side wall portions <NUM>, the electrically conductive terminal <NUM> can be fixed by the two side wall portions <NUM>. Thus, for example, the amount of adhesive or the like used to fix the electrically conductive terminal <NUM> can be reduced.

Next, a configuration of a lighting device according to a fifth modified example will be described with reference to <FIG> and <FIG>. <FIG> and <FIG> are schematic plan views of the lighting device according to the fifth modified example. Note that the periphery of the corner portion <NUM> is illustrated enlarged in <FIG>.

As illustrated in <FIG>, in a lighting device 1E according to the fifth modified example, the electrically conductive terminal <NUM> is in contact with the corner portion <NUM>. In this way, by bringing the electrically conductive terminal <NUM> into contact with the corner portion <NUM>, the vibration of the electrically conductive terminal <NUM> can be suppressed by the substrate <NUM>. Accordingly, the reliability in the vibration environment of the lighting device <NUM> can be further improved.

As illustrated in <FIG>, the lighting device 1E according to the fifth modified example includes two electrically conductive terminals <NUM>, and each of the two electrically conductive terminals <NUM> is located in a recessed region of corresponding one of the two corner portions <NUM> located diagonally. With such a configuration, a position shift of the substrate <NUM> due to vibration or the like can be suppressed by the two electrically conductive terminals <NUM>. Specifically, in the corner portions <NUM>, having the inverted-R shape can suppress not only the position shift in the diagonal direction in which the two electrically conductive terminals <NUM> are disposed, but also the position shift in a diagonal direction orthogonal to the diagonal direction in which the two electrically conductive terminals <NUM> are disposed, as compared with a case in which the corner portions have the C-plane shape. Accordingly, the reliability in the vibration environment of the lighting device <NUM> can be further improved.

Here, the example is given in which each of the electrically conductive terminals <NUM> is in contact with only corresponding one of the corner portions <NUM>, but each of the electrically conductive terminals <NUM> may be in contact with the corresponding one of the corner portions <NUM> and also in contact with the side wall portions <NUM>. Each of the electrically conductive terminals <NUM> may be in contact with the corresponding one of the corner portions <NUM> and also sandwiched by two side wall portions <NUM> adjacent to each other. In other words, each of the electrically conductive terminals <NUM> may be sandwiched by the corresponding one of the corner portions <NUM> and the two side wall portions <NUM> adjacent to each other.

Next, a configuration of a substrate according to a sixth modified example will be described with reference to <FIG> is a schematic plan view of the substrate according to the sixth modified example.

As illustrated in <FIG>, a region surrounded by two virtual lines <NUM> and <NUM> connecting end points of the first sides 111a facing each other and two virtual lines <NUM> and <NUM> connecting end points of the second sides 111b facing each other is defined as a region R2. In a substrate 10F according to the sixth modified example, a circuit mounting region R3 in the circuit forming surface <NUM> overlaps the region R2, and extends outward from the region R2. Specifically, the circuit mounting region R3 is longer than the region R2 in the X-axis direction and in the Y-axis direction.

As described above, by disposing the circuit mounting region R3 outward from the region R2, the circuit mounting region R3 can be more widely ensured in the substrate 10F including the inverted-R shaped corner portions <NUM>. Note that the circuit mounting region R3 is a region in which the wirings <NUM>, the light emitting element <NUM>, and the like can be mounted.

As described above, with the electronic device according to the embodiments, by configuring the corner portions of the substrate in the inverted-R shape, damage to the corner portions of the substrate can be suppressed while using the housing part with the exposed corner portions of the substrate.

Claim 1:
A lighting device comprising:
a substrate (<NUM>) made of a ceramic; and
a housing part (<NUM>) comprising a recessed portion (<NUM>) configured to accommodate the substrate (<NUM>), wherein
the recessed portion (<NUM>) comprises
a plurality of side wall portions (<NUM>) arranged around the substrate (<NUM>) along a circumferential direction and respectively facing a plurality of sides (<NUM>) of the substrate (<NUM>) in a plan view when viewing the substrate (<NUM>) from a direction perpendicular to a circuit forming surface (<NUM>) of the substrate (<NUM>), and
a plurality of gaps (<NUM>) each located between two of the plurality of side wall portions (<NUM>) adjacent to each other in the circumferential direction,
the substrate (<NUM>) comprises a plurality of corner portions (<NUM>) curved toward an inner side of the circuit forming surface (<NUM>) in the plan view, and
the lighting device further comprises
wiring (<NUM>) located on the circuit forming surface (<NUM>), and
a plurality of electrically conductive terminals (<NUM>) connected to the wiring (<NUM>), caracterized in that
at least a portion of each of the plurality of electrically conductive terminals (<NUM>) is located in a recessed region of each of the plurality of corner portions (<NUM>).