JP2019041006A - Substrate support structure, irradiation device, and image forming apparatus - Google Patents

Abstract

To obtain a substrate support structure that prevents warpage of a substrate due to a difference in linear expansion between front and rear faces, compared with a case where a substrate has a wiring pattern formed on one face and has a metal foil solid pattern on the other face.SOLUTION: A substrate support structure comprises: a plate-like printed wiring board 50; a wiring pattern that is formed on a front face of the printed wiring board 50; a metal foil pattern 56 that is formed on a rear face 52B of the printed wiring board 50 and has exposed portions of a substrate 52 between metal foil portions; and a heat sink to which the metal foil pattern 56 is adhered with an adhesive and supports the printed wiring board 50.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a substrate support structure, an irradiation apparatus, and an image forming apparatus.

  Patent Document 1 below discloses a method of performing die bonding by recognizing an image of a mark and a chip outer shape of a semiconductor chip and relatively correcting the position of a predetermined portion of the semiconductor chip and a mount portion.

  Patent Document 2 listed below discloses a method for forming an insulating resin layer on a wiring board that can reduce the generation of voids in the insulating resin layer by applying vibration to a laminate that is heated and pressurized.

  Patent Document 3 listed below is a joined body in which a metal substrate and a ceramic substrate are bonded together via an adhesive, and a deformable metal heat transfer body is provided on at least one of the metal substrate and the ceramic substrate. A configuration for direct joining is disclosed. The joining is performed at a temperature equal to or higher than the melting point of the metal heat transfer body, and solder, brazing material or the like is used as the metal heat transfer body.

  Patent Document 4 below discloses an optical component structure that eliminates the influence of voids by eliminating the adhesive in the portion corresponding to the optical path.

JP 2003-133340 A JP 2004-050655 A JP 11-058596 A JP 2017-103435 A

  The present invention provides a substrate support structure that suppresses the warpage of the substrate due to the difference in linear expansion between the front and back, compared to the case where the other surface of the substrate having a wiring pattern formed on one surface is a solid pattern of metal foil. Is the purpose.

  The substrate support structure according to the first aspect of the present invention includes a plate-shaped substrate, a wiring pattern formed on one surface of the substrate, and a metal foil portion formed on the other surface of the substrate. A metal foil pattern having an exposed portion of the base material of the substrate, and a support member that supports the substrate by bonding the metal foil pattern with an adhesive.

  According to a second aspect of the present invention, in the substrate support structure according to the first aspect, the exposed portion of the base material in the metal foil pattern reaches the outer periphery of the substrate directly or indirectly.

  The invention according to claim 3 is the substrate support structure according to claim 1 or 2, wherein the exposed portion of the base material in the metal foil pattern includes a groove-shaped portion long in a specific direction, All portions of the exposed portion of the base material reach the outer periphery of the substrate directly or through the groove shape.

  According to a fourth aspect of the present invention, in the substrate support structure according to the first aspect, the exposed portion of the base material in the metal foil pattern has a groove shape long in a specific direction.

  According to a fifth aspect of the present invention, in the substrate support structure according to the fourth aspect, the end portion of the groove shape reaches the outer periphery of the substrate.

  The invention according to claim 6 is the substrate support structure according to claim 5, wherein the metal foil pattern has a plurality of groove shapes.

  According to a seventh aspect of the present invention, in the substrate support structure according to the sixth aspect, all groove-shaped end portions reach the outer periphery of the substrate.

  According to an eighth aspect of the present invention, in the substrate support structure according to the sixth aspect, at least a part of the groove shape reaches the outer periphery of the substrate through another groove shape.

  According to a ninth aspect of the present invention, in the substrate support structure according to any one of the sixth to eighth aspects, the plurality of groove shapes include a groove group arranged in a specific direction.

  According to a tenth aspect of the present invention, in the substrate support structure according to the ninth aspect, the plurality of groove shapes include a plurality of groove groups intersecting each other.

  According to an eleventh aspect of the present invention, in the substrate support structure according to the tenth aspect, the plurality of groove shapes are lattice shapes.

  According to a twelfth aspect of the present invention, in the substrate support structure according to any one of the sixth to eighth aspects, the plurality of groove shapes are radial.

  According to a thirteenth aspect of the present invention, in the substrate support structure according to the twelfth aspect, in the plurality of groove shapes, a starting point of radiation is located at a central portion of the substrate.

  According to a fourteenth aspect of the present invention, in the substrate support structure according to any one of the fifth to thirteenth aspects, the width of the groove shape is constant or gradually widens toward the outer periphery of the substrate. It has become.

  The invention according to claim 15 is the substrate support structure according to any one of claims 6 to 14, wherein the wiring pattern includes a plurality of wiring portions arranged in a specific direction, and the wiring portions. And a plurality of groove shapes are arranged in a direction in which the inter-wiring portions are arranged.

  According to a sixteenth aspect of the present invention, in the substrate support structure according to any one of the first to fifteenth aspects, the metal foil pattern occupies the total area of the wiring portion occupying the wiring pattern. The total area of the metal foil is not less than 0.5 times and not more than 3 times.

  The invention according to claim 17 is the substrate support structure according to any one of claims 1 to 16, wherein a heating member is mounted on the substrate, and the support member is a heat dissipation member. Or it is a heat-transfer member which conveys heat to a heat radiating member.

  An irradiation apparatus according to an invention of claim 18 is supplied with a current via the substrate support structure according to any one of claims 1 to 17 and the wiring pattern of the substrate. And a light emitting element supported by the support member.

  An image forming apparatus according to a nineteenth aspect of the present invention is a liquid droplet ejecting unit that ejects liquid droplets onto a recording medium, and a drying device that uses the irradiation device according to the eighteenth aspect to dry the droplets; Have

  According to the first aspect of the present invention, the warpage of the substrate due to the difference in linear expansion between the front and back surfaces compared to the case where the other surface of the substrate on which the wiring pattern is formed on one surface is a solid pattern of metal foil. Is suppressed.

  According to invention of Claim 2, compared with the case where the exposed part is surrounded by metal foil, the adhesive strength of a board | substrate and a supporting member is high.

  According to the third aspect of the present invention, the adhesive strength between the substrate and the support member is increased as compared with the case where a part of the exposed portion is surrounded by the metal foil.

  According to the fourth aspect of the present invention, the adhesive strength between the substrate and the support member is increased as compared with the case where the exposed portion is circular or square.

  According to the fifth aspect of the present invention, the adhesive strength between the substrate and the support member is increased as compared with the case where the groove-shaped exposed portion is surrounded by the metal foil.

  According to the sixth aspect of the present invention, the adhesive strength between the substrate and the support member is increased as compared with the case where there is a single groove shape.

  According to the seventh aspect of the present invention, the bonding strength between the substrate and the support member is increased as compared with the case where some of the groove-shaped end portions do not reach the outer periphery of the substrate.

  According to the eighth aspect of the present invention, the bonding strength between the substrate and the support member is increased as compared with the case where some of the groove shapes are surrounded by other groove shapes.

  According to the ninth aspect of the present invention, the warpage of the substrate due to the difference in linear expansion between the front and back surfaces is suppressed as compared with the case where a plurality of groove shapes are randomly arranged.

  According to the tenth aspect of the present invention, the adhesive strength between the substrate and the support member is increased as compared with the case where the plurality of groove groups do not intersect each other.

  According to the eleventh aspect of the present invention, the adhesive strength between the substrate and the support member is increased as compared with the case where the intersecting groove shapes are arranged asymmetrically.

  According to the twelfth aspect of the present invention, the adhesive strength between the substrate and the support member is increased as compared with the case where the plurality of groove shapes are not joined.

  According to the thirteenth aspect of the present invention, the bonding strength between the substrate and the support member is increased as compared with the case where the starting point of radiation is located at the end of the substrate.

  According to the invention described in claim 14, the adhesive strength between the substrate and the support member is increased as compared with the case where the width of the groove shape becomes narrower toward the outer periphery of the substrate.

  According to the fifteenth aspect of the present invention, the warpage of the substrate due to the difference in front and back linear expansion is suppressed as compared with the case where the plurality of groove shapes are arranged so as to intersect with the direction in which the inter-wiring portions are arranged. The

  According to the invention of claim 16, the total area of the metal foil in the metal foil pattern is smaller than 0.5 times and larger than 3 times the total area of the wiring portion in the wiring pattern. Thus, the warpage of the substrate due to the difference in linear expansion between the front and back surfaces is suppressed.

  According to the invention described in claim 17, the substrate is easily cooled in the configuration in which the heat of the heat generating member is released through the metal foil pattern.

  According to the invention described in claim 18, the warpage of the substrate due to the difference in linear expansion between the front and back surfaces is suppressed as compared with the case where the other surface of the substrate provided in the substrate support structure is a solid pattern of metal foil. The

  According to the nineteenth aspect of the present invention, compared to the case where the other surface of the substrate provided in the substrate support structure is a solid pattern of metal foil, the warpage of the substrate due to the difference in linear expansion between the front and back surfaces is suppressed. The

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. It is a perspective view which shows an example of the irradiation apparatus used for the image forming apparatus shown in FIG. It is a perspective view which shows the support structure of the board | substrate of 1st Embodiment used for the irradiation apparatus shown in FIG. It is a perspective view which shows the surface of the board | substrate used for the support structure of the board | substrate of 1st Embodiment. It is a top view which shows the surface of the board | substrate used for the support structure of the board | substrate of 1st Embodiment. It is a bottom view which shows the back surface of the board | substrate used for the support structure of the board | substrate of 1st Embodiment. It is sectional drawing which shows the board | substrate used for the support structure of the board | substrate of 1st Embodiment. It is a perspective view which shows the back surface of the board | substrate used for the support structure of the board | substrate of 2nd Embodiment. It is a bottom view which shows the back surface of the board | substrate used for the support structure of the board | substrate of 2nd Embodiment. It is a bottom view which shows the back surface of the board | substrate used for the support structure of the board | substrate of 3rd Embodiment. It is a bottom view which shows the back surface of the board | substrate used for the support structure of the board | substrate of 4th Embodiment. It is a bottom view which shows the back surface of the board | substrate used for the support structure of the board | substrate of 5th Embodiment. It is a bottom view which shows the back surface of the board | substrate used for the support structure of the board | substrate of 6th Embodiment.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the direction indicated by the arrow UP is the upward direction in the vertical direction of the image forming apparatus, and the direction indicated by the arrow W is the apparatus width direction (horizontal direction). In addition, the direction indicated by the arrow D, that is, the direction orthogonal to each of the apparatus height direction and the apparatus width direction is defined as an apparatus depth direction (horizontal direction). In addition, in this specification, when there is a numerical range represented using “to”, the numerical range means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

[First Embodiment]
<Overall configuration of image forming apparatus>
FIG. 1 is a schematic configuration diagram illustrating an example of a configuration of an image forming apparatus according to an embodiment of the present invention. As shown in FIG. 1, the image forming apparatus 10 is an ink jet recording apparatus that forms an image on a recording medium by ejecting ink droplets as an example of droplets.

  The image forming apparatus 10 includes a plurality of transport rolls 24 that transport a continuous paper P as an example of a recording medium in the direction of arrow A, and a recording head 12 as an example of a droplet discharge unit that discharges ink droplets onto the continuous paper P. And an irradiation device 14 that irradiates the continuous paper P on which the ink droplets are discharged with laser light. Further, the image forming apparatus 10 includes a paper feed roll 20 that supplies the continuous paper P and a take-up roll 22 that winds the continuous paper P.

  A long continuous paper P is wound around the paper supply roll 20. The continuous paper P drawn from the paper supply roll 20 is conveyed in the direction of arrow A as the conveyance roll 24 rotates. The continuous paper P conveyed by the conveyance roll 24 is finally taken up by the rotation of the take-up roll 22. Between the paper feed roll 20 and the take-up roll 22, the recording head 12 and the irradiation device 14 are arranged so as to face the continuous paper P in order from the upstream side in the transport direction of the continuous paper P. Hereinafter, the transport direction of the continuous paper P may be simply referred to as “transport direction”.

  In the present embodiment, the recording head 12 is an inkjet recording head (hereinafter abbreviated as “recording head”) 12Y corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K). 12M, 12C, 12K. The recording heads 12Y, 12M, 12C, and 12K are arranged in the order described from the upstream side to the downstream side in the conveyance direction of the continuous paper P. Each of the recording heads 12 </ b> Y, 12 </ b> M, 12 </ b> C, and 12 </ b> K ejects ink of a corresponding color from a plurality of nozzles to form an image of a corresponding color on the continuous paper P. In addition, when it is not necessary to distinguish each color of YMCK, the colors are collectively referred to as “recording head 12”.

  The irradiation device 14 includes a plurality of laser light emitting elements 42 (see FIG. 2), and is configured to irradiate the continuous paper P on which ink droplets are ejected by the recording head 12 from the plurality of laser light emitting elements 42. ing. Thereby, the ink droplets of the image formed on the continuous paper P are dried, and the image is fixed on the continuous paper P. Here, the irradiation device 14 is an example of a drying device. The irradiation device 14 will be described later.

  The image forming apparatus 10 is provided with a plurality of containers 30Y, 30M, 30C, and 30K that store ink corresponding to the respective colors of the recording heads 12Y, 12M, 12C, and 12K. Each of the containers 30Y, 30M, 30C, and 30K supplies the stored ink to the corresponding recording heads 12Y, 12M, 12C, and 12K.

  In the image forming apparatus 10 described above, ink droplets are ejected by the recording head 12 onto the continuous paper P drawn from the paper supply roll 20 to form an image. The continuous paper P on which the image is formed by the recording head 12 is irradiated with laser light by the irradiation device 14, and the ink droplets of the image formed on the continuous paper P are dried. Further, the continuous paper P from which the ink droplets of the image have been dried is taken up by the take-up roll 22, thereby completing the image formation on the continuous paper P.

<Configuration of irradiation device>
FIG. 2 is a perspective view showing an example of the laser element unit 40 used in the irradiation apparatus 14 according to the embodiment of the present invention.

  As shown in FIG. 2, the laser element unit 40 has a rectangular parallelepiped shape as an example. Although not shown, the irradiation device 14 includes a plurality of laser element units 40 arranged along the device depth direction (arrow D direction) as an example. In the present embodiment, the width direction of the continuous paper P (the direction perpendicular to the arrow A that is the conveyance direction of the continuous paper P shown in FIG. 1) is the apparatus depth direction (arrow D direction), and a plurality of laser elements The unit 40 is arranged along the width direction of the continuous paper P. In the present embodiment, the plurality of laser element units 40 are arranged so that the longitudinal direction thereof is the width direction of the continuous paper P (the apparatus depth direction, that is, the arrow D direction). For example, the plurality of laser element units 40 are arranged in a staggered manner in a plurality of rows in the apparatus width direction (arrow W direction).

(Configuration of laser element unit)
As shown in FIG. 2, the laser element unit 40 includes a laser array 44 in which a plurality of laser light emitting elements 42 as an example of light emitting elements are arranged side by side, and a heat sink 46 as an example of a heat dissipation member that cools the laser array 44. And. The heat sink 46 has a rectangular parallelepiped shape, for example. In the present embodiment, a laser array 44 including a plurality of laser light emitting elements 42 is provided on the lower surface portion of the heat sink 46 in the vertical direction of the irradiation device 14. The laser array 44 is provided on the lower surface portion of the intermediate portion 46 </ b> A in the longitudinal direction of the heat sink 46. The plurality of laser light emitting elements 42 are arranged side by side along the longitudinal direction and along the direction orthogonal to the longitudinal direction at the intermediate portion 46A excluding the end of the heat sink 46.

  The laser element unit 40 includes a printed wiring board 50 to which the substrate support structure of the first embodiment is applied on both sides of the laser array 44 in the longitudinal direction. The printed wiring board 50 is supported by the lower surface portions of the end portions 46B on both sides of the heat sink 46 in the longitudinal direction. The heat sink 46 is disposed across the laser array 44 and the printed wiring boards 50 on both sides. Here, the printed wiring board 50 is an example of a substrate, and the heat sink 46 is an example of a support member. The two printed wiring boards 50 in FIG. 2 are formed symmetrically on both sides of the heat sink 46 in the longitudinal direction. 3 is an enlarged perspective view of the printed wiring board 50 on the left side in the longitudinal direction of the heat sink 46 in FIG.

  As shown in FIG. 3, the printed wiring board 50 includes a plate-like base material 52 made of an insulator and a conductive wiring pattern formed on a surface 52 </ b> A as an example of one surface of the base material 52. 54 (see FIGS. 4, 5 and 7). As shown in FIG. 6, the printed wiring board 50 includes a copper foil pattern 56 formed on the back surface 52 </ b> B as an example of the other surface of the base material 52. The base material 52 is rectangular in plan view. The copper foil pattern 56 is an example of a metal foil pattern. The copper foil pattern 56 will be described in detail later.

  As shown in FIGS. 4 and 5, the wiring pattern 54 includes a plurality of wiring portions 54 </ b> A formed on the surface 52 </ b> A of the base material 52. Between the plurality of wiring parts 54 </ b> A, the surface 52 </ b> A of the base material 52 is exposed between the wirings. The wiring pattern 54 including the plurality of wiring portions 54A is formed, for example, by patterning a copper foil formed on the entire surface 52A of the substrate 52 by photolithography. In the present embodiment, the plurality of wiring portions 54 </ b> A are arranged side by side in the apparatus width direction (W direction) on the surface 52 </ b> A of the base material 52, and each other from the end face side of the end portion 46 </ b> B of the heat sink 46 toward the laser array 44. Are formed so that the interval between them (the width of the portion between the wirings) increases. That is, the plurality of wiring parts 54A are spaced from each other (the width of the part between the wirings) from the one end part 55A arranged on the end face side of the end part 46B of the heat sink 46 toward the other end part 55B arranged on the laser array 44 side. ) Are spread out.

  As shown in FIG. 3, one end portions 55A of the plurality of wiring portions 54A are respectively connected to the conductive portions 60A of the plurality of cables 60 (see FIG. 2). The conductive portions 60A of the plurality of cables 60 are respectively connected to external power supply boards (not shown). Further, the other end portions 55B of the plurality of wiring portions 54A are respectively connected to the laser light emitting elements 42 arranged on one end side in the longitudinal direction of the laser array 44 (on the left side of the printed wiring board 50 in FIG. 2) by bonding wires 62. Has been. Further, adjacent laser light emitting elements 42 arranged in the longitudinal direction of the laser array 44 are connected by bonding wires 64.

  As shown in FIG. 6, the copper foil pattern 56 includes a plurality of island-shaped copper foil portions 72 that are copper foil portions and a plurality of groove portions 74 that are exposed portions of the base material 52 between the copper foil portions 72. (See FIG. 7). Here, the copper foil is an example of a metal foil. The copper foil pattern 56 is formed by, for example, patterning the copper foil formed on the entire back surface 52B of the base material 52 by photolithography. The plurality of groove portions 74 include groove-shaped portions that are long in a specific direction. More specifically, the plurality of groove portions 74 extend radially from the central portion 74A of the exposed portion as an example of the starting point of radiation toward the outer periphery of the base member 52, and the end portions of the plurality of groove portions 74 are the base portions. The outer periphery of the material 52 is reached. The central portion 74 </ b> A is located at the central portion of the base material 52. In the present embodiment, each of the extending central portions 74 </ b> A is a groove portion 74. In addition, some of the plurality of groove portions 74 extend radially from the intermediate portion of the base material 52 toward the outer periphery of the base material 52 without being connected to the central portion 74 </ b> A, and the end portions reach the outer periphery of the base material 52. ing. In the present embodiment, all of the end portions on the outer peripheral side of the base material 52 in the plurality of groove portions 74 directly reach the outer periphery of the base material 52. The width of the plurality of groove portions 74 is constant. The copper foil pattern 56 includes an exposed portion of the base material 52 (a portion without the copper foil portion 72) on the entire circumference of the outer peripheral portion of the base material 52.

  As shown in FIG. 7, the printed wiring board 50 is arranged so that the copper foil pattern 56 on the back surface 52 </ b> B of the base material 52 is on the upper side in the vertical direction, and the adhesive 76 is applied to the back surface 52 </ b> B side of the base material 52. . As a result, the adhesive 76 is applied to the copper foil portion 72 of the copper foil pattern 56. The printed wiring board 50 is bonded to the longitudinal end portion 46B of the heat sink 46 by bonding the copper foil portion 72 of the copper foil pattern 56 to the longitudinal end portion 46B of the heat sink 46 via the adhesive 76. Is done. For example, the adhesive 76 is a thermosetting adhesive that is cured by heating. Accordingly, the adhesive 76 is cured by applying heat at the time of bonding, and the printed wiring board 50 and the heat sink 46 are joined by the adhesive 76. At this time, the adhesive 76 applied to the copper foil portion 72 of the copper foil pattern 56 enters the side surface of the groove portion 74, and the adhesive strength is increased by the anchor effect of the adhesive 76. As the adhesive, a heat conductive adhesive is preferable.

Here, the linear expansion coefficient of copper is 1.68 × 10 ⁻⁵ / ° C. Specifically, the linear expansion coefficient is measured using a thermomechanical analysis (TMA) method in accordance with JIS K7197.

Moreover, the base material 52 is formed of an insulator, and glass epoxy or the like is used as an example. Glass epoxy is a glass fiber that is impregnated with an epoxy resin and heat-cured to form a plate. Here, the linear expansion coefficient of the epoxy resin was 2 × 10 ⁻⁴ / ° C.

  In the printed wiring board 50, the total area of the plurality of wiring portions 54A occupying the wiring pattern 54 on the surface 52A of the base material 52 and the total area of the copper foil portions 72 occupying the copper foil pattern 56 on the back surface 52B of the base material 52 are as follows. It is preferable to make it close. In the printed wiring board 50, the total area of the copper foil part 72 occupying the copper foil pattern 56 is preferably 0.5 times or more and 3 times or less of the total area of the plurality of wiring parts 54A occupying the wiring pattern 54. It is more preferably 0.7 times or more and 2.5 times or less, and further preferably 0.8 times or more and 2 times or less. In the printed wiring board 50 of the present embodiment, the total area of the copper foil part 72 occupying the copper foil pattern 56 is 0.5 times or more and 3 times or less of the total area of the plurality of wiring parts 54A occupying the wiring pattern 54. It is comprised so that it may become.

(Function and effect)
Next, the operation and effect of this embodiment will be described.

  The printed wiring board 50 includes a plate-like substrate 52 made of an insulator, a conductive wiring pattern 54 formed on the surface 52A of the substrate 52, and a copper foil formed on the back surface 52B of the substrate 52. And a pattern 56. The wiring pattern 54 includes a plurality of wiring portions 54 </ b> A formed on the surface 52 </ b> A of the base material 52. The copper foil pattern 56 includes a plurality of island-shaped copper foil portions 72 and a plurality of groove-shaped groove portions 74 that are exposed portions of the base material 52 between the copper foil portions 72. The copper foil portion 72 of the copper foil pattern 56 is bonded to the longitudinal end portion 46 </ b> B of the heat sink 46 by an adhesive 76, whereby the printed wiring board 50 is supported by the heat sink 46.

  In the laser element unit 40 including the printed wiring board 50 described above, a plurality of cables 60, a plurality of wiring portions 54A constituting the wiring pattern 54, and bonding wires 62 and 64 are provided from an external power supply substrate (not shown). A current is supplied to the plurality of laser light emitting elements 42. As a result, the plurality of laser light emitting elements 42 emit light, and the continuous paper P is irradiated with laser light, whereby the ink droplets of the image formed on the continuous paper P are dried (see FIG. 1).

  Here, the support structure of the printed wiring board of a comparative example is demonstrated. Although not shown, in the support structure of the printed wiring board of the comparative example, a solid copper foil part is formed on the entire back surface of the base material constituting the printed wiring board except for the outer periphery. There are no exposed parts between the parts. Further, the entire solid copper foil portion is bonded to the heat sink by an adhesive. Thereby, the printed wiring board is supported by the heat sink. In addition, the other structure of the printed wiring board of a comparative example is the same as the structure of the printed wiring board 50 of this embodiment.

  In the support structure of the printed wiring board of this comparative example, since the copper foil portion has a large area, voids may remain when the adhesive is cured by heating. Moreover, in this printed wiring board support structure, the surface of the base material is a wiring pattern, and the back surface of the base material is a solid copper foil part. For this reason, the printed wiring board is warped due to the difference in linear expansion between the front and back surfaces due to heating during bonding, and it is difficult to bond the printed wiring board and the heat sink uniformly. Also, with this printed wiring board support structure, when voids remain in the adhesive due to heating during bonding, the bonding area between the printed wiring board and the heat sink decreases, which may lead to a decrease in adhesive strength. is there. Also, with this printed wiring board support structure, when voids remain in the adhesive due to heating during bonding, the bonding area between the printed wiring board and the heat sink decreases, so the thermal resistance increases and the heat sink is heated. Becomes difficult to escape.

  On the other hand, in the support structure of the printed wiring board 50 of this embodiment, the copper foil pattern 56 is formed on the back surface 52B of the base material 52, and the copper foil pattern 56 includes a plurality of island-shaped copper foil portions 72 and , And a plurality of groove-shaped groove portions 74 which are exposed portions of the base material 52 between the copper foil portions 72. For this reason, in the support structure of the printed wiring board 50 described above, due to the difference in linear expansion between the front and back surfaces, compared to the case where the other surface of the substrate on which the wiring pattern is formed on one surface is a solid pattern of metal foil. Warpage of the printed wiring board 50 is suppressed. For example, when a flat cable is used for the cable 60 and a manufacturing process is used in which a plurality of wiring portions 54A are soldered together with a heater seal, soldering with little variation is possible by suppressing warping of the printed wiring board 50. is there.

  Further, in the support structure for the printed wiring board 50 described above, the plurality of groove portions 74 that are exposed portions of the base material 52 in the copper foil pattern 56 directly reach the outer periphery of the printed wiring board 50 (Configuration 1). As a result, voids generated by heating at the time of bonding easily escape to the outside through the plurality of grooves 74 from the adhesive 76 that bonds the printed wiring board 50 and the heat sink 46. For this reason, the voids in the layer of the adhesive 76 are reduced, and the porosity of the layer of the adhesive 76 is reduced, so that the adhesive strength between the printed wiring board 50 and the heat sink 46 is increased. For this reason, in the above-mentioned support structure for the printed wiring board 50, the adhesive strength between the printed wiring board 50 and the heat sink 46 is higher than when the exposed portion is surrounded by the metal foil.

  Further, in the support structure of the printed wiring board 50 described above, the exposed portion of the base material 52 in the copper foil pattern 56 includes a plurality of groove portions 74 that are long in a specific direction, and the plurality of groove portions 74 are directly printed. It has reached the outer periphery of the wiring board 50 (Configuration 2). For this reason, voids generated by heating during bonding from the layer of the adhesive 76 easily escape to the plurality of groove portions 74. Therefore, in the support structure of the printed wiring board 50 described above, the adhesive strength between the printed wiring board 50 and the heat sink 46 is increased as compared with the case where a part of the exposed portion is surrounded by the metal foil.

  Further, in the support structure for the printed wiring board 50 described above, the exposed portion of the base material 52 in the copper foil pattern 56 is a groove 74 that is long in a specific direction (Configuration 3). For this reason, the boundary between the copper foil portion 72 and the groove portion 74 is long, and voids generated from the adhesive 76 due to heating during bonding easily escape to the groove portion 74. Moreover, the adhesive strength is increased by the adhesive effect of the adhesive 76 having a long edge per area by the adhesive 76 entering the groove 74. For this reason, in the support structure of the printed wiring board 50 described above, the adhesive strength between the printed wiring board 50 and the heat sink 46 is increased as compared with the case where the exposed portion is a circle or square having the same area.

  Further, in the support structure for the printed wiring board 50 described above, the copper foil pattern 56 includes a plurality of groove portions 74 (Configuration 4). For this reason, in the support structure of the printed wiring board 50 described above, the adhesive strength between the printed wiring board 50 and the heat sink 46 is increased as compared with the case where there is a single groove shape.

  Further, in the support structure for the printed wiring board 50 described above, the end portions of all the plurality of groove portions 74 reach the outer periphery of the printed wiring board 50 (Configuration 5). For this reason, in the above-described support structure for the printed wiring board 50, the bonding strength between the printed wiring board 50 and the heat sink 46 is increased as compared with the case where the end portions of some of the grooves do not reach the outer periphery of the substrate.

  In the support structure for the printed wiring board 50, the plurality of groove portions 74 are radial (Configuration 6). For this reason, in the support structure of the printed wiring board 50 described above, the adhesive strength between the printed wiring board 50 and the heat sink 46 is increased as compared with the case where the plurality of groove shapes are not joined.

  Further, in the support structure for the printed wiring board 50 described above, the radiation starting points of the plurality of groove portions 74 are located at the center of the base material 52 (Configuration 7). For this reason, in the support structure of the printed wiring board 50 described above, the adhesive strength between the printed wiring board 50 and the heat sink 46 is increased as compared with the case where the starting point of radiation is located at the end of the substrate.

  Further, in the support structure for the printed wiring board 50 described above, the widths of the plurality of groove portions 74 are constant toward the outer periphery of the substrate 52 (Configuration 8). For this reason, in the support structure for the printed wiring board 50 described above, the adhesive strength between the printed wiring board 50 and the heat sink 46 is increased as compared with the case where the width of the groove shape becomes narrower toward the outer periphery of the substrate.

  Further, in the support structure for the printed wiring board 50 described above, the total area of the copper foil portion 72 occupying the copper foil pattern 56 is 0.5 times or more the total area of the plurality of wiring portions 54A occupying the wiring pattern 54. It is less than or equal to twice (Configuration 9) For this reason, in the support structure of the printed wiring board 50, the total area of the metal foil in the metal foil pattern is smaller than 0.5 times and larger than 3 times the total area of the wiring portion in the wiring pattern. As compared with the above, warping of the printed wiring board 50 due to the difference in linear expansion between the front and back surfaces is suppressed.

  In the support structure for the printed wiring board 50, a plurality of laser light emitting elements 42 are mounted on the printed wiring board 50, and the printed wiring board 50 is supported by the heat sink 46 (Configuration 10). Thereby, the heat of the laser light emitting element 42 can be released to the heat sink 46 through the copper foil pattern 56. For this reason, in the support structure of the printed wiring board 50 described above, the printed wiring board 50 is easily cooled in the configuration in which the heat of the heat generating member is released through the metal foil pattern.

[Second Embodiment]
Next, the irradiation apparatus and the substrate support structure according to the second embodiment of the present invention will be described with reference to FIGS. In addition, about the same component as 1st Embodiment mentioned above, the same number is attached | subjected and the description is abbreviate | omitted.

  8 and 9 show the back surface 52B of the substrate 52 of the printed wiring board 90. FIG. As shown in FIGS. 8 and 9, the printed wiring board 90 includes a copper foil pattern 92 formed on the back surface 52 </ b> B of the base material 52. The copper foil pattern 92 includes a plurality of island-shaped copper foil portions 94 that are copper foil portions, and a plurality of groove-shaped groove portions 96 that are exposed portions of the base material 52 between the copper foil portions 94. Yes. Here, the printed wiring board 90 is an example of a substrate, and the copper foil is an example of a metal foil.

  The plurality of groove portions 96 are in a lattice shape. In other words, the plurality of groove portions 96 include groove groups 96A and 96B that intersect each other. As an example, the plurality of groove portions 96 include a groove group 96 </ b> A having a groove-shaped portion that is long in the longitudinal direction of the base material 52 (W direction that is the device width direction), and a direction (device depth) that is orthogonal to the longitudinal direction of the base material 52. A groove group 96B having a long groove-shaped portion in the direction D). In the present embodiment, all the end portions of the plurality of groove portions 96 reach the outer periphery of the base material 52 directly. The configuration of the printed wiring board 90 other than the copper foil pattern 92 is the same as that of the printed wiring board 50 of the first embodiment.

  In the support structure of the printed wiring board 90 described above, the printed wiring board due to the difference in linear expansion between the front and back surfaces is compared with the case where the other surface of the substrate on which the wiring pattern is formed on one surface is a solid pattern of metal foil. 90 warpage is suppressed. The support structure for the printed wiring board 90 includes the same configuration as the configuration 1, the configuration 2, the configuration 3, the configuration 4, the configuration 5, the configuration 8, the configuration 9, and the configuration 10 of the first embodiment. Since these effects are the same as those of the first embodiment, they are omitted.

  In the support structure of the printed wiring board 90 described above, a plurality of groove portions 96 include groove groups 96A and 96B that intersect each other. For this reason, in the support structure of the printed wiring board 90 described above, the adhesive strength between the printed wiring board 90 and the heat sink 46 is increased as compared with the case where the plurality of groove groups do not intersect each other.

  Further, in the support structure for the printed wiring board 90 described above, the plurality of groove portions 96 have a lattice shape. For this reason, in the support structure of the printed wiring board 90 described above, the adhesive strength between the printed wiring board 50 and the heat sink 46 is increased as compared with the case where the intersecting groove shapes are arranged asymmetrically.

  Further, in the support structure for the printed wiring board 90 described above, the plurality of groove portions 96 are inter-wiring portions where the substrate 52 is exposed between the plurality of wiring portions 54A formed on the surface 52A of the substrate 52 (see FIG. 5). ) In the same direction. For this reason, in the support structure for the printed wiring board 90 described above, the printed wiring board 110 has a linear expansion difference between the front and back surfaces as compared with the case where the plurality of groove shapes are arranged to intersect the direction in which the exposed portions are arranged. Warpage is suppressed.

[Third Embodiment]
Next, an irradiation apparatus and a substrate support structure according to a third embodiment of the present invention will be described with reference to FIG. In addition, about the same component as 1st and 2nd embodiment mentioned above, the same number is attached | subjected and the description is abbreviate | omitted.

  FIG. 10 shows the back surface 52 </ b> B of the base material 52 of the printed wiring board 100. As shown in FIG. 10, the printed wiring board 100 includes a copper foil pattern 102 formed on the back surface 52 </ b> B of the base material 52. The copper foil pattern 102 includes a plurality of island-shaped copper foil portions 104 that are copper foil portions, and a plurality of groove-shaped groove portions 106 that are exposed portions of the base material 52 between the copper foil portions 104. Yes. Here, the printed wiring board 100 is an example of a substrate, and the copper foil is an example of a metal foil.

  A part of the plurality of groove portions 106B extends radially from a central portion 106A as an example of a starting point of radiation toward the outer periphery of the base member 52, and an end portion of the groove portion 106B is an outer periphery of the base member 52. Has reached. The central portion 106 </ b> A is located in the central portion of the base material 52. In addition, another part of the plurality of groove portions 106C extends from the intermediate portion of the base material 52 toward the outer periphery of the base material 52 without being connected to the central portion 106A, and the end portion of the groove portion 106C is a base portion. The outer periphery of the material 52 is reached. Further, a plurality of curved groove portions 106D are provided so as to connect the plurality of radially extending groove portions 106. In the present embodiment, the plurality of groove portions 106 reach the outer periphery of the base material 52 directly or indirectly. The configuration of the printed wiring board 100 other than the copper foil pattern 102 is the same as that of the printed wiring board 50 of the first embodiment.

  In the above-described support structure for the printed wiring board 100, the printed wiring board due to the difference in linear expansion between the front and back surfaces compared to the case where the other surface of the substrate having the wiring pattern formed on one surface is a solid pattern of metal foil. 100 warpage is suppressed. Further, the support structure of the printed wiring board 100 has the same configuration as the configuration 1, the configuration 2, the configuration 4, the configuration 6, the configuration 7, the configuration 8, the configuration 9, and the configuration 10 of the first embodiment. Since these effects are the same as those of the first embodiment, they are omitted.

  In the support structure for the printed wiring board 100 described above, the plurality of groove portions 106 reach the outer periphery of the substrate 52 directly or indirectly. For this reason, in the support structure of the printed wiring board 100 described above, the adhesive strength between the printed wiring board 100 and the heat sink is increased as compared with the case where the exposed portion is surrounded by the metal foil.

[Fourth Embodiment]
Next, an irradiation apparatus and a substrate support structure according to a fourth embodiment of the present invention will be described with reference to FIG. In addition, about the same component as 1st-3rd embodiment mentioned above, the same number is attached | subjected and the description is abbreviate | omitted.

  FIG. 11 shows the back surface 52 </ b> B of the substrate 52 of the printed wiring board 110. As shown in FIG. 11, the printed wiring board 110 includes a copper foil pattern 112 formed on the back surface 52 </ b> B of the base material 52. The copper foil pattern 112 includes a plurality of island-shaped copper foil portions 114 that are copper foil portions, and a plurality of groove-shaped groove portions 116 that are exposed portions of the base material 52 between the copper foil portions 114. Yes. Here, the printed wiring board 110 is an example of a substrate, and the copper foil is an example of a metal foil.

  The plurality of groove portions 116 are arranged side by side in the longitudinal direction of the base material 52 (W direction which is the device width direction) and are orthogonal to the longitudinal direction of the base material 52 (the D direction which is the device depth direction). ). In other words, the plurality of groove portions 116 have a groove group arranged in a direction orthogonal to the longitudinal direction of the base material 52. In the printed wiring board 110, the plurality of groove portions 116 are arranged in the direction in which the exposed portions (see FIG. 5) between the plurality of wiring portions 54A formed on the surface 52A of the substrate 52 are arranged. In the present embodiment, the plurality of groove portions 116 directly reach the outer periphery of the base material 52. The configuration of the printed wiring board 110 other than the copper foil pattern 112 is the same as that of the printed wiring board 50 of the first embodiment.

  In the above-described support structure for the printed wiring board 110, the printed wiring board due to the difference in linear expansion between the front and back surfaces is compared with the case where the other surface of the substrate on which the wiring pattern is formed on one surface is a solid pattern of metal foil. 110 warpage is suppressed. Further, the support structure of the printed wiring board 110 includes the same configuration as the configuration 1, the configuration 2, the configuration 3, the configuration 4, the configuration 5, the configuration 8, the configuration 9, and the configuration 10 of the first embodiment. Since these effects are the same as those of the first embodiment, they are omitted.

  In the support structure for the printed wiring board 110 described above, the plurality of groove portions 116 have groove groups arranged in a direction orthogonal to the longitudinal direction of the base material 52. For this reason, compared with the case where several groove shape is arrange | positioned at random, the curvature of the printed wiring board 110 by the difference in front and back linear expansion is suppressed.

  Further, in the support structure of the printed wiring board 110 described above, the plurality of groove portions 116 are arranged in the direction in which the exposed portions (see FIG. 5) between the plurality of wiring portions 54A formed on the surface 52A of the base material 52 are arranged. Yes. For this reason, in the support structure of the printed wiring board 110 described above, the printed wiring board 110 has a linear expansion difference due to the difference in front and back linear expansion as compared with the case where the plurality of groove shapes are arranged to intersect the direction in which the exposed portions are arranged. Warpage is suppressed.

[Fifth Embodiment]
Next, an irradiation apparatus and a substrate support structure according to a fifth embodiment of the present invention will be described with reference to FIG. In addition, about the same component as 1st-4th embodiment mentioned above, the same number is attached | subjected and the description is abbreviate | omitted.

  FIG. 12 shows the back surface 52 </ b> B of the base material 52 of the printed wiring board 120. As shown in FIG. 12, the printed wiring board 120 includes a copper foil pattern 122 formed on the back surface 52 </ b> B of the base material 52. The copper foil pattern 122 includes a plurality of island-shaped copper foil portions 124 that are copper foil portions, and a plurality of groove-shaped groove portions 126 that are exposed portions of the base material 52 between the copper foil portions 124. Yes. Here, the printed wiring board 120 is an example of a substrate, and the copper foil is an example of a metal foil.

  A part of the plurality of groove portions 126 extends radially from a central portion 126 </ b> A as an example of a starting point of radiation toward the outer periphery of the substrate 52. All the end portions of the plurality of groove portions 126 reach the outer periphery of the base material 52 directly. The central portion 126 </ b> A is located in the central portion of the base material 52. In the present embodiment, the bottom surface of the base material 52 shown in FIG. 12 is formed symmetrically on the left and right of the center line along the longitudinal direction of the base material 52 and is orthogonal to the longitudinal direction of the base material 52. Are formed symmetrically above and below the center line along the line. The configuration of the printed wiring board 120 other than the copper foil pattern 122 is the same as that of the printed wiring board 50 of the first embodiment.

  In the support structure of the printed wiring board 120 described above, the printed wiring board due to the difference in linear expansion between the front and back surfaces compared to the case where the other surface of the substrate having the wiring pattern formed on one surface is a solid pattern of metal foil. 120 warpage is suppressed. Further, the above-described support structure for the printed wiring board 120 has the same configuration as the configuration 1, the configuration 2, the configuration 3, the configuration 4, the configuration 6, the configuration 7, the configuration 8, the configuration 9, and the configuration 10 of the first embodiment. Since these effects are the same as those of the first embodiment, they are omitted.

  Further, in the support structure for the printed wiring board 120 described above, all of the plurality of grooves 126 directly reach the outer periphery of the substrate 52. For this reason, in the support structure of the printed wiring board 120 described above, the adhesive strength between the printed wiring board 120 and the heat sink is increased as compared with the case where some of the groove-shaped end portions do not reach the outer periphery.

[Sixth Embodiment]
Next, an irradiation apparatus and a substrate support structure according to a sixth embodiment of the present invention will be described with reference to FIG. In addition, about the same component as 1st-5th embodiment mentioned above, the same number is attached | subjected and the description is abbreviate | omitted.

  FIG. 13 shows the back surface 52 </ b> B of the base material 52 of the printed wiring board 130. As shown in FIG. 13, the printed wiring board 130 includes a copper foil pattern 132 formed on the back surface 52 </ b> B of the base material 52. The copper foil pattern 132 includes a plurality of island-shaped copper foil portions 134 that are copper foil portions, and a plurality of groove-shaped groove portions 136 that are exposed portions of the base material 52 between the copper foil portions 134. Yes. Here, the printed wiring board 130 is an example of a substrate, and the copper foil is an example of a metal foil.

  The plurality of groove portions 136 extend radially from the center portion 136 </ b> A as an example of the starting point of radiation toward the outer periphery of the base material 52, and the end portions of the plurality of groove portions 136 reach the outer periphery of the base material 52. The central portion 136A is located in the central portion of the base material 52. Further, some of the plurality of groove portions 136 are not connected to the center portion 136 </ b> A and extend from the intermediate portion of the base material 52 toward the outer periphery of the base material 52, and the end portions thereof reach the outer periphery of the base material 52. . In the present embodiment, all of the end portions of the plurality of groove portions 136 reach the outer periphery of the base material 52 directly. Further, the width of the plurality of groove portions 74 gradually increases toward the outer periphery of the base material 52. The configuration of the printed wiring board 130 other than the copper foil pattern 132 is the same as that of the printed wiring board 50 of the first embodiment.

  In the support structure of the printed wiring board 130 described above, the printed wiring board due to the difference in linear expansion between the front and back surfaces is compared with the case where the other surface of the substrate on which the wiring pattern is formed on one surface is a solid pattern of metal foil. The warpage of 130 is suppressed. Further, the support structure of the printed wiring board 130 has the same configuration as the configuration 1, the configuration 2, the configuration 3, the configuration 4, the configuration 6, the configuration 7, the configuration 9, and the configuration 10 of the first embodiment. Since these effects are the same as those of the first embodiment, they are omitted.

  In the support structure for the printed wiring board 130 described above, all of the plurality of grooves 136 directly reach the outer periphery of the substrate 52. For this reason, in the support structure for the printed wiring board 130 described above, the adhesive strength between the printed wiring board 130 and the heat sink is increased as compared with the case where some of the groove-shaped end portions do not reach the outer periphery.

  Further, in the support structure for the printed wiring board 130 described above, the width of the plurality of groove portions 136 gradually increases toward the outer periphery of the substrate 52. For this reason, compared with the case where the width | variety of a groove shape becomes narrow toward the outer periphery of a board | substrate, the adhesive strength of the printed wiring board 130 and a heat sink increases.

  In the first to sixth embodiments, the image forming apparatus 10 that forms an image on the continuous paper P is used. However, the image forming apparatus of the present invention is not limited to the continuous paper P. For example, the present invention can be applied to an image forming apparatus that sequentially conveys sheets to form an image.

  In the first to sixth embodiments, the laser element unit includes a plurality of laser light emitting elements 42, but the present invention is not limited to this, and the number of laser light emitting elements 42 can be changed. In the present invention, a laser element unit including one or two or more laser light emitting elements 42 is applicable. In the first to sixth embodiments, the direction in which the laser element unit and the printed wiring board are arranged can be changed.

  Moreover, in 1st-6th embodiment, although copper foil was used for the wiring pattern of the surface of the base material of a printed wiring board, and the copper foil pattern was formed in the back surface of a base material, this invention is limited to copper foil. However, a metal foil made of another metal material may be used.

  In the second to fifth embodiments, the width of the plurality of grooves constituting the copper foil pattern is constant. However, the present invention is not limited to this configuration, for example, toward the outer periphery of the substrate. The width of the plurality of grooves may be gradually increased.

  In the first to sixth embodiments, the printed wiring board is supported by the heat sink, but the present invention is not limited to this configuration. For example, the printed wiring board may be supported by a heat transfer member that is interposed between the heat sink and easily transfers heat. Further, for example, the printed wiring board may be supported by a cooling unit provided with a flow path in which a coolant is circulated.

  In the first to sixth embodiments, the configuration of the image forming apparatus 10 may be changed. For example, the irradiation device 14 may be provided for each of the recording heads 12Y, 12M, 12C, and 12K for each color.

  In the first to sixth embodiments, the printed wiring board support structure as an example of the substrate is applied to the irradiation device 14, but the present invention is not limited to this configuration. For example, you may apply this invention to the support structure of base materials other than a printed wiring board. For example, you may use the support structure of the board | substrate of this invention for many uses, such as a laser processing machine.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor. Also, the power supply and signal wiring diagrams supplied to each laser element unit are omitted.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Recording head (an example of droplet discharge means)
14 Irradiation device (an example of a drying device)
46 heat sink (an example of a heat dissipation member, an example of a support member)
50 Printed wiring board (an example of a substrate)
52 base 52A surface (an example of one surface)
52B Back side (an example of the other side)
54 wiring pattern 54A wiring part 56 copper foil pattern (an example of a metal foil pattern)
72 Copper foil part (an example of metal foil part)
74 Groove (an example of groove shape)
74A Center part (example of starting point)
76 Adhesive 90 Printed wiring board (an example of substrate)
92 Copper foil pattern (an example of metal foil pattern)
94 Copper foil part (an example of metal foil part)
96 Groove (an example of groove shape)
96A Groove group 96B Groove group 100 Printed wiring board (an example of a substrate)
102 Copper foil pattern (an example of metal foil pattern)
104 Copper foil part (an example of metal foil part)
106 Groove (an example of groove shape)
106A Center part (example of starting point)
110 Printed wiring board (an example of a substrate)
112 Copper foil pattern (an example of metal foil pattern)
114 Copper foil part (an example of metal foil part)
116 groove (an example of groove shape)
120 Printed wiring board (an example of a substrate)
122 Copper foil pattern (an example of metal foil pattern)
124 Copper foil part (an example of metal foil part)
126 Groove (an example of groove shape)
126A Center part (example of starting point)
130 Printed wiring board (an example of a substrate)
132 Copper foil pattern (an example of metal foil pattern)
134 Copper foil part (an example of metal foil part)
136 Groove (an example of groove shape)
136A Center part (example of starting point)
P Continuous paper (an example of a recording medium)

Claims (19)

A plate-like substrate;
A wiring pattern formed on one surface of the substrate;
A metal foil pattern formed on the other surface of the substrate and having an exposed portion of the base material of the substrate between the metal foil portions;
The metal foil pattern is bonded by an adhesive, and a support member for supporting the substrate;
A substrate support structure comprising:   The substrate support structure according to claim 1, wherein an exposed portion of the base material in the metal foil pattern reaches the outer periphery of the substrate directly or indirectly.   The exposed portion of the base material in the metal foil pattern includes a groove-shaped portion that is long in a specific direction, and all the exposed portions of the base material reach the outer periphery of the substrate directly or through the groove shape. The substrate support structure according to claim 1 or 2.   The substrate support structure according to claim 1, wherein the exposed portion of the base material in the metal foil pattern has a groove shape long in a specific direction.   The substrate support structure according to claim 4, wherein an end of the groove shape reaches an outer periphery of the substrate.   The substrate support structure according to claim 5, wherein the metal foil pattern has a plurality of groove shapes.   The substrate support structure according to claim 6, wherein all groove-shaped end portions reach the outer periphery of the substrate.   The substrate support structure according to claim 6, wherein at least a part of the groove shape reaches the outer periphery of the substrate through another groove shape.   The substrate support structure according to any one of claims 6 to 8, wherein the plurality of groove shapes includes a groove group arranged in a specific direction.   The substrate support structure according to claim 9, wherein the plurality of groove shapes include a plurality of groove groups intersecting each other.   The substrate support structure according to claim 10, wherein the plurality of groove shapes are lattice shapes.   The substrate support structure according to any one of claims 6 to 8, wherein the plurality of groove shapes are radial.   The substrate support structure according to claim 12, wherein the plurality of groove shapes have a radiation starting point located at a central portion of the substrate.   The substrate support structure according to any one of claims 5 to 13, wherein the width of the groove shape is constant or gradually widens toward an outer periphery of the substrate. The wiring pattern has a plurality of wiring parts arranged in a specific direction, and an inter-wiring part separating the wiring parts,
The substrate support structure according to any one of claims 6 to 14, wherein the plurality of groove shapes are arranged in a direction in which the inter-wiring portions are arranged.   The total area of the metal foil occupying the metal foil pattern is 0.5 to 3 times the total area of the wiring portion occupying the wiring pattern. A support structure for a substrate as described in 1.   17. The substrate support according to claim 1, wherein a heat generating member is mounted on the substrate, and the support member is a heat radiating member or a heat transfer member that transfers heat to the heat radiating member. Construction. A substrate support structure according to any one of claims 1 to 17,
A current is supplied through the wiring pattern of the substrate, and a light emitting element supported by the support member;
Irradiation device having Droplet discharge means for discharging droplets to a recording medium;
A drying device that uses the irradiation device according to claim 18 to dry the droplets;
An image forming apparatus.