JP5574756B2 - Light emitting element array and printing apparatus - Google Patents

Description

  The present invention relates to a light emitting element array and a printing apparatus.

  In recent years, printing methods using ultraviolet curable ink (UV ink) have attracted attention in industrial applications for reasons such as diversification of printing media, consideration for the environment, and increase in printing speed. In printing using UV ink, the UV ink is attached to a print medium, and the attached ink is irradiated with ultraviolet light (UV light) to cure the UV ink in a short time.

  Conventionally, fluorescent lamps such as a high-pressure mercury lamp and a low-pressure mercury lamp have been used as a light source of an ultraviolet irradiation head for curing such ultraviolet-curable ink. 2. Description of the Related Art Recently, for example, an ink jet recording apparatus described in Patent Document 1 is a printing apparatus using, as an irradiation light source, a UV-LED array in which a plurality of UV-LED elements that emit UV light are arranged on one main surface of a substrate. Proposed.

JP 2005-104108 A

  In a printing apparatus using this UV-LED array as an irradiation light source, if UV light is not irradiated to the UV ink, the UV ink remains without being cured. When attempting to connect UV-LED arrays mounted on a plurality of substrates in an attempt to expand the irradiation range of UV light, there may be a gap that is not irradiated with UV light.

  The present invention has been devised in view of such problems in the prior art. An object of the present invention is to provide a light emitting element array and a printing apparatus that can irradiate a wide range.

The light emitting element array according to the present invention includes a plurality of support substrates arranged along a first direction, and a plurality of support substrates arranged along the first direction and a second direction intersecting the first direction on the plurality of support substrates. a plurality of light emitting elements being provided with a said supporting substrate are both is recessed from only the upper surface of the supporting substrate, a plurality of first recess portion for accommodating at least one of said light-emitting element, any Also formed from the upper surface and the side surface of the support substrate so as to straddle the upper surface and the side surface
Has a plurality of second recess portions being, the second recess portion, at least one of said light emitting becomes the second recess portion of the supporting substrate adjacent to each other in the first direction pair Accommodates the element.

  The printing apparatus of the present invention includes the light emitting element array described above, a transport mechanism that transports the recording medium in the second direction, an attachment mechanism that attaches a photosensitive material that is sensitive to light emitted from the light emitting element to the recording medium, It has.

  According to the present invention, it is possible to provide a light emitting element array and a printing apparatus that can irradiate a wide range.

It is a schematic block diagram of the light irradiation head which shows an example of embodiment of the light emitting element array of this invention. It is the top view to which the principal part of the light irradiation head shown in FIG. 1 was expanded. It is sectional drawing along the III-III line shown in FIG. It is the figure which abbreviate | omitted the one part structure of the light irradiation head shown in FIG. It is the figure which expanded the principal part of the light irradiation head shown in FIG. It is a schematic block diagram of the light irradiation head which shows the other example of embodiment of the light emitting element array of this invention. It is a schematic block diagram which shows an example of embodiment of the printing apparatus of this invention. It is a side view of the printing apparatus shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are illustrative, and the present invention is not limited to these embodiments.

<First Embodiment of Light-Emitting Element Array>
In this embodiment, the light irradiation head 10 shown in FIGS. 1-5 is employ | adopted as a light emitting element array. The light irradiation head 10 includes a support base 20, a plurality of support substrates 30, a plurality of light emitting elements 40, a wiring conductor 50, and a sealing material 60.

  The support base 20 has a function of supporting the plurality of support substrates 30. A plurality of support substrates 30 are arranged on the support base 20 along the first directions D1 and D2 and the second directions D3 and D4. Examples of the material for forming the support base 20 include various metal materials, ceramics, and resin materials. The support base 20 is preferably a material having a high thermal conductivity. The support base 20 of this embodiment is formed of copper.

  The support substrate 30 has a function of supporting the plurality of light emitting elements 40. A plurality of the support substrates 30 are arranged on the support base 20. The plurality of support substrates 30 are arranged along the first directions D1 and D2 and the second directions D3 and D4. The side surfaces of the plurality of support substrates 30 extend along the second directions D3 and D4. The support substrate 30 is formed with a plurality of first recess portions 30a that are recessed from the upper surface. The first recess 30a is arranged along the first direction D1, D2 and the second direction D3, D4.

  Further, the support substrate 30 is formed with a side surface facing the other support substrate 30 and a second recess 30b that is recessed from the upper surface. The second depressions 30b are arranged along the second directions D3 and D4. As for this 2nd hollow part 30b, two formed in the adjacent support substrate 30 makes a pair, and comprises one synthetic | combination hollow part 30c. In this synthetic hollow portion 30c, two second hollow portions 30b may face each other, or two second hollow portions 30b may be separated from each other. This synthetic | combination hollow part 30c is arranged along 2nd direction D3, D4.

  The support substrate 30 according to the present embodiment includes a first substrate 31 and a second substrate 32. The second substrate 32 is formed on the first substrate 31.

  The second substrate 32 has a through hole 32a penetrating in the thickness directions D5 and D6. The through hole 32 a has openings on the upper surface and the lower surface of the second substrate 32. The opening on the lower surface side of the through hole 32 a is closed with the first substrate 31. The first recess 30a of the support substrate 30 is formed by the through hole 32a of the second substrate 32 and the first substrate 31 closing one of the openings of the through hole 32a.

Moreover, the 2nd board | substrate 32 has the groove | channel 32b on the side surface. The groove 32b is formed on the second substrate 32.
Through the thickness direction D5, D6. The groove 32 b has openings on the upper surface, the lower surface, and the side surface of the second substrate 32. In the groove 32 b, the opening on the lower surface side is closed by the first substrate 31. The second recess 30b of the support substrate 30 is formed by the groove 32b of the second substrate 32 and the first substrate 31 closing the opening on the lower surface side of the groove 32b.

  The support substrate 30 is made of, for example, an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a ceramic such as a glass ceramic, an epoxy resin, and a resin such as a liquid crystal polymer (LCP). It is formed.

  In the manufacturing method of the support substrate 30 when the support substrate 30 is made of ceramics or the like, first, a plurality of green sheets to be the support substrate 30 are prepared by firing. Next, a metal paste that becomes the wiring conductor 50 through the electrical connection between the light emitting element 40 and the input terminal is disposed between the green sheets. As a metal paste used as this wiring conductor 50, what contains metals, such as tungsten (W), molybdenum (Mo), manganese (Mn), and copper (Cu), is mentioned, for example. Next, the support substrate 30 having the wiring conductor 50 can be formed by firing the metal paste together with firing the support substrate 30. Such a wiring conductor 50 may be formed using the known metallization method, plating method or the like.

  Moreover, in the manufacturing method of the said support substrate 30 in case the support substrate 30 is the insulator which consists of resin, the precursor of the resin used as the support substrate 30 is first prepared by hardening | curing. Next, the lead terminal that becomes the wiring conductor 50 through the electrical connection between the light emitting element 40 and the input terminal is embedded in the resin precursor that becomes the support substrate 30. When embedding in the precursor, one end of the lead terminal is led out to the mounting portion on the light emitting element 40 side, and the other end is exposed from the side surface and the lower surface of the support substrate 30, so that it is electrically connected to other elements. Can be connected. Examples of the material for forming the lead terminal include metal materials such as Cu, Ag, Al, iron (Fe) -nickel (Ni) -cobalt (Co) alloy, and Fe-Ni alloy.

  The light emitting element 40 has a function of irradiating light. A plurality of the light emitting elements 40 are arranged on the support substrate 30. The light emitting element 40 is accommodated in the first recess 30a. The light emitting element 40 is disposed at the center of the first recess 30a. The light emitting element 40 is accommodated in the synthetic recess 30c. That is, the light emitting elements 40 are arranged along the first directions D1 and D2 and the second directions D3 and D4. The light emitting element 40 of the present embodiment straddles the two second dents 30 constituting the synthetic dent 30c, and is disposed at the center of the synthetic dent 30c.

  The light emitting element 40 is configured by providing a light emitting layer 42 on a first main surface of an element substrate 41. Examples of the element substrate 41 include sapphire. Examples of the light emitting layer 42 include those made of a compound semiconductor such as GaN. In the present embodiment, a light emitting layer 42 is provided on the main surface on the side facing the upper surface of the first substrate 31 among the two main surfaces of the element substrate 41 in order to flip-chip connect the light emitting element 40. ing.

  In the present embodiment, a material that emits UV light having a wavelength peak spectrum of light of 380 [nm] or less is employed. That is, in this embodiment, a UV-LED element is employed as the light emitting element 40. In the light emitting layer 42, a plurality of semiconductor layers are stacked on the first main surface of the element substrate 41 (note that the semiconductor layers are not shown individually). More specifically, for example, the light emitting layer 42 includes, from the first main surface of the element substrate 41, a first semiconductor layer of one of n-type and p-type conductivity, a first contact layer, A semiconductor layer of the second conductivity type opposite to the first semiconductor layer and a second contact layer are formed by being stacked in this order.

  In addition, element electrodes 43 and 44 mainly composed of Ag, for example, are provided on the surface of the light emitting layer 42 facing the first substrate 31. These device electrodes 43 and 44 provided on the surface of the light emitting layer 42 are connected to the wiring conductor 50 provided on the support substrate 30. The light emitting element 40 of the present embodiment is disposed in a flip chip state on one main surface of the first substrate 31. The light emitting layer 42 emits light having a light amount corresponding to the amount of current flowing between the device electrodes 43 and 44. The element substrate 41 of the present embodiment is made of sapphire and has relatively good transparency with respect to the light emitted from the light emitting layer 42. In the present embodiment, the light emitting element 40 is controlled by the amount of current, but may be controlled by the magnitude of the voltage.

  In the present embodiment, for example, the light emitting element 42 having a size of about 0.6 [mm] × 0.6 [mm] in a plan view is provided on the first main surface of the first substrate 31 with about 2. They are arranged with a relatively small mounting interval of 6 mm.

  In the light irradiation head 10, the light emitted from the light emitting element 40 toward the inner peripheral surfaces of the first depression 30 a and the synthesis depression 30 c of the second substrate 32 is the first depression 30 a and the synthesis depression 30 c. It is comprised so that it may reflect upwards in the inner peripheral surface of this, and may irradiate efficiently upwards in a figure. The second substrate 32 of the present embodiment is made of porous ceramic that is visually recognized as white under a white light source. This ceramic is selected so as to have a relatively good reflectivity with respect to light in the ultraviolet region, for example. Examples of the ceramic employed as the second substrate 32 include an aluminum oxide sintered body, a zirconium oxide sintered body, and an aluminum nitride sintered body. The second substrate 32 may be made of an epoxy resin and a resin such as a liquid crystal polymer (LCP). Further, in order to achieve the desired reflectivity, the inner peripheral surface of the through hole 32a and the groove 32b of the second substrate 32 is made of metallic material according to the material of the second substrate 32, the wavelength of light emitted from the light emitting element 40, and the like. A reflective film may be provided. Such a metallic reflective film can be formed by, for example, metal plating, vapor deposition, or the like.

  The wiring conductor 50 is responsible for electrical connection of the plurality of light emitting elements 40. In the wiring conductor 50 of the present embodiment, a wiring electrode 50a is provided on the bottom surface of the first recess 30a. The wiring electrode 50 a is electrically connected to the element electrodes 43 and 44 of the light emitting element 40.

  As the sealing material 60, a material that transmits light emitted from the light emitting element 40 satisfactorily is selected. As this sealing material 60, a silicone resin is mentioned, for example. Further, a material closer to the refractive index of the element substrate 41 is selected as the refractive index of the sealing material 60 compared to about 1.0 which is the refractive index of air. The sealing material 60 of the present embodiment is formed of a silicone resin having a refractive index of about 1.4, and is formed of sapphire having a refractive index of 1.7 compared to air having a refractive index of about 1.0. The value is close to that of the element substrate 41.

  In the light irradiation head 10, a plurality of support substrates 30 arranged along the first directions D <b> 1 and D <b> 2, and the first directions D <b> 1 and D <b> 2 and the first directions D <b> 1 and D <b> 2 on the plurality of support substrates 30. And a plurality of light emitting elements 40 arranged along intersecting second directions D3 and D4. The support substrate 30 is recessed from the upper surface, and includes a plurality of first recess portions 30a that accommodate one light emitting element 40, and a plurality of second recess portions 30b that are recessed from the upper surface and side surfaces. The 2nd hollow part 30b comprises the synthetic | combination hollow part 30c which accommodates one light emitting element 40 by making a pair with the 2nd hollow part 30b of the other support substrate 30 adjacent in 1st direction D1, D2. In the light irradiation head 10, a synthetic recess 30 c is provided in a region between the two support substrates 30. Therefore, the light irradiation head 10 can irradiate light over a wide range even if a plurality of support substrates 30 are arranged.

<Second Embodiment of Light-Emitting Element Array>
In the light irradiation head 10 </ b> A of the present embodiment shown in FIG. 6, the arrangement of the light emitting elements 40 is different from that of the light irradiation head 10. In the present embodiment, only differences from the light irradiation head 10 will be described. Moreover, about the component similar to the light irradiation head 10, the overlapping description is abbreviate | omitted using the same referential mark.

  In the light irradiation head 10A, two light emitting elements 40 are accommodated in the first recess 30a. Further, in this light irradiation head 10A, the light emitting element 40 is accommodated in each of the two second recess portions 30b constituting the synthetic recess portion 30c.

  In this light irradiation head 10A, since one light emitting element 40 is accommodated in each of the paired second depressions 30b, the light emitting element 40 is placed even if the interval between the adjacent support substrates 30 is widened. Can do. Therefore, in this light irradiation head 10A, the variation by manufacture can be permitted. In the light irradiation head 10, the stress due to thermal expansion can be relieved by the distance between the support substrates 30.

<Printing device>
As an embodiment of the printing apparatus of the present invention, the printing apparatus 1 shown in FIGS. 7 and 8 will be described as an example. The printing apparatus 1 includes a light irradiation head 10 as a light emitting element array, a transport mechanism 11, an inkjet head 12 as an attachment mechanism, and a control mechanism 13. Although the printing apparatus 1 of the present embodiment employs the light irradiation head 10 as the light emitting element array, the light irradiation head 10A may be employed.

  The transport mechanism 11 has a function of transporting the recording medium 90 in the second directions D3 and D4. The transport mechanism 11 is configured such that the recording medium 90 passes through the inkjet head 12 and the light irradiation head 10 in this order. The transport mechanism 11 includes a mounting table 111 and a transport roller 112. The mounting table 111 mounts the recording medium 90, and the transport roller 112 moves the recording medium 90 in the second directions D3 and D4.

  The ink jet head 12 has a function of attaching a photosensitive material to a recording medium 90 that is transported via the transport mechanism 11. The ink-jet head 12 is configured to eject droplets containing the photosensitive material toward the recording medium 90 so as to adhere to the recording medium 90. In the present embodiment, ultraviolet curable ink (UV ink) is used as the photosensitive material. Examples of the photosensitive material include, in addition to UV ink, a photosensitive resist, a photocurable resin, and the like.

  In the present embodiment, a line-type inkjet head is employed as the inkjet head 12. The inkjet head 12 is longer than the recording medium 90 in the first directions D1 and D2 intersecting the second directions D3 and D4, and causes the UV ink to adhere to the entire first main surface of the recording medium 90. It is configured. In the present embodiment, the first direction D1, D2 and the second direction D3, D4 are orthogonal. Further, the first directions D1 and D2 are along the direction in which the first main surface of the recording medium 90 expands. In other words, the first main surface of the recording medium 90 extends in the surface direction constituted by the first directions D1, D2 and the second directions D3, D4.

  The inkjet head 12 has a plurality of ejection holes 12a, and is configured to eject UV ink from the ejection holes 12a. The inkjet head 12 is provided with a plurality of ejection holes 12a at intervals such that the UV ink attached to the first main surface of the recording medium 90 does not leave an interval in the first directions D1 and D2.

  In the present embodiment, the inkjet head 12 is taken as an example of the attachment mechanism, but the present invention is not limited to this. For example, a serial type ink jet head may be employed as the attachment mechanism. Moreover, you may employ | adopt a line type or a serial type spray head as an adhesion mechanism. Furthermore, an electrostatic head that accumulates static electricity of the recording medium 90 and adheres the photosensitive material with the static electricity may be employed as the attachment mechanism. Further, as the attachment mechanism, an immersion apparatus that immerses the recording medium 90 in a liquid photosensitive material and attaches the photosensitive material may be employed. Furthermore, you may employ | adopt a brush, a brush, and a roller as an adhesion mechanism.

  In the printing apparatus 1, the light irradiation head 10 has a function of exposing a recording medium 90 to which a photosensitive material is adhered, which is transported through a transport mechanism 11. The light irradiation head 10 is provided on the downstream side of the inkjet head 12 in the second directions D3 and D4. In the printing apparatus 1, the light emitting element 40 has a function of exposing the photosensitive material attached to the recording medium 90.

  The control mechanism 13 has a function of controlling the light emission of the light irradiation head 10. The memory of the control mechanism 13 stores information indicating the characteristics of light that makes it relatively good to cure the ink droplets ejected from the inkjet head 12. Specific examples of the stored information include wavelength distribution characteristics suitable for curing ejected ink droplets, and numerical values representing emission intensity (emission intensity in each wavelength range). In the printing apparatus 1 according to the present embodiment, by including the control mechanism 13, the magnitude of the drive current input to the plurality of light emitting layers 42 can be adjusted based on the stored information of the control mechanism 13. Therefore, according to the printing apparatus 1, it is possible to irradiate the light with an appropriate amount of light according to the characteristics of the ink to be used, and it is possible to cure the ink droplets with relatively low energy light.

  In the printing apparatus 1, the transport mechanism 11 transports the recording medium 90 in the second directions D3 and D4. The inkjet head 12 discharges UV ink to the recording medium 90 being conveyed, and causes the UV ink to adhere to the surface of the recording medium 90. At this time, the UV ink attached to the recording medium 90 may be attached to the entire surface, partially attached, or attached in a desired pattern. In the printing apparatus 1, UV ink emitted from the light irradiation head 10 is irradiated onto the UV ink attached to the recording medium 90 to cure the UV ink.

  The printing apparatus 1 according to the present embodiment can enjoy the effects of the light irradiation head 10. Therefore, the printing apparatus 1 can irradiate the recording medium 90 with UV light over a wide range. Therefore, the printing apparatus 1 can irradiate the photosensitive material with UV light.

  In the printing apparatus 1 according to the present embodiment, the UV light can also be irradiated to the region between the support substrates 30, so that the light irradiation head 10 can be disposed close to the recording medium 90. Therefore, this printing apparatus 1 is suitable for reducing the size.

  While specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  In this embodiment, the example which applied the light irradiation head to the printing apparatus 1 using the inkjet head 12 is shown. This light irradiation head 10 can be applied to curing various types of photo-curing resins, such as a dedicated device for curing a photo-curing resin spin-coated on the surface of the object. Further, for example, it may be used as an irradiation light source in an exposure apparatus.

Further, the embodiment of the printing apparatus 1 is not limited to the above embodiment. For example, a so-called offset printing type printer that rotates a shaft-supported roller and conveys a recording medium along the roller surface may exhibit the same effect.

DESCRIPTION OF SYMBOLS 1 ... Printing apparatus 10 ... Light irradiation head 11 ... Conveyance mechanism 111 ... Mounting stand 112 ... Conveyance roller 12 ... Inkjet head 12a ... Discharge hole 13 ... Control mechanism 20 ... support base 30 ... support substrate 30a ... first recess 30b ... second recess 30c ... synthetic recess 31 ... first substrate 32 ... second substrate 32a .... Through hole 32b ... Groove 40 ... Light emitting element 41 ... Element substrate 42 ... Light emitting layer 43, 44 ... Element electrode 50 ... Wiring conductor 50a ... Wiring electrode 60 ... .Sealant 90 ... recording medium

Claims (4)

A plurality of support substrates arranged along a first direction; and a plurality of light emitting elements arranged on the plurality of support substrates along the first direction and a second direction intersecting the first direction; , And
The support substrate is
All are recessed from only the upper surface of the support substrate , and a plurality of first recesses for accommodating at least one of the light emitting elements,
Each of which has a plurality of second recessed portions that are recessed from the upper surface and the side surface of the support substrate and formed across the upper surface and the side surface ,
Said second recess, said second recess portion of the supporting substrate adjacent to each other in the first direction to accommodate at least one of said light emitting elements as a pair, the light-emitting element array.   The light-emitting element according to claim 1, wherein the light-emitting element straddles the second recess portion to be a pair.   The light emitting element array according to claim 1 or 2, wherein at least one of the light emitting elements is accommodated in each of the pair of second recesses. The light emitting element array according to any one of claims 1 to 3,
A transport mechanism for transporting the recording medium in the second direction;
And an attachment mechanism for attaching a photosensitive material that is sensitive to light emitted from the light emitting element to the recording medium.

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