JP2009188237A - Manufacturing method of light emitting element array chip, microlens mold, light emitting element head, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method etc., of a light emitting element array chip in which mold releasability of a microlens mold is good by suppressing projection of a light-curing resin when microlenses are formed on LEDs by hardening the light-curing resin. <P>SOLUTION: The manufacturing method of the light emitting array chip 100 is characterized in that the microlenses 103 are formed on the LEDs 102 by including the steps of: housing the light-curing resin 302 in a plurality of hole portions 205 and recessed portions 202 by pressing the microlens mold 200, having a substrate, the plurality of hole portions 205 formed on a surface of the substrate and having a transfer shape of the shape of a microlens 103 and the recessed portions 202, each formed in an outer circumferential region of a hole portion 205 and having a chromium film 203 formed on a bottom part, against the light-curing resin 302; irradiating the light-curing resin 302 housed in the hole portion 205 with light to harden it, and not to harden the light-curing resin 302 housed in the recessed portion 202 because of the chromium film 203 serving as a light shield film; and removing the unhardened light-curing resin 302. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a light emitting element array chip, and more particularly to a method for manufacturing a light emitting element array chip in which a microlens is formed on a light emitting element.

  In image forming apparatuses such as printers, copiers, and facsimiles that employ an electrophotographic method, after obtaining an electrostatic latent image by irradiating image information onto a uniformly charged photoreceptor by optical recording means The electrostatic latent image is visualized by adding toner, and the image is formed by transferring and fixing on the recording paper. As such optical recording means, in addition to an optical scanning method in which a laser is used to scan and expose a laser beam in the main scanning direction, in recent years, a large number of LED (Light Emitting Diode) array light sources are arranged in the main scanning direction. An optical recording means using an LED head is employed.

  The image forming apparatus using the LED array light source does not require a scanning space and does not require a drive system, as compared with an optical scanning type image forming apparatus, so that the entire image forming apparatus is downsized and reliable. There is an advantage of improvement. In addition, there is an advantage that it is resistant to deformation of the optical system due to vibration and heat.

  On the other hand, since each LED element in the LED array light source has a wide light emission angle, it is difficult for light to efficiently enter the photosensitive drum. In order to solve this point, Patent Document 1 proposes a microlens array in which a lens such as a microlens corresponding to each LED element is incorporated.

Various methods for producing the microlens array have been proposed. For example, in Patent Document 2, a transparent resin layer is formed on a light emitting element substrate on which the light emitting element array is formed, and the transparent resin layer corresponds to each light emitting element. A convex (or concave) step is formed at the position to be heated, and the transparent resin layer on which the step is formed is heated to transform each step into a highly aspherical lens shape, thereby forming a microlens array integrally. A method has been proposed.
Further, Patent Document 3 proposes a method of manufacturing a microlens array by applying a high refractive resin on a molding surface on which concave portions are formed, pressing and unfolding a glass substrate, and curing the high refractive resin. .
And in patent document 4, the manufacturing method of the micro lens array using the shaping | molding die with a spacer is proposed.

Japanese Patent Laid-Open No. 6-24042 JP-A-11-202103 Japanese Patent Laid-Open No. 11-123771 JP 2006-327182 A

In a system in which a microarray lens is formed on a light-emitting element by molding a resin using a mold, it is also required to suppress the protrusion of the resin and to easily release the mold.
An object of the present invention is to provide a method for manufacturing a light-emitting element array chip and the like that can prevent the resin from protruding during molding and can easily release the mold.

  According to the first aspect of the present invention, a substrate, a plurality of holes having a transfer shape in the shape of a microlens formed on the surface of the substrate, and a light-shielding film is formed in the outer peripheral region of the hole. The step of accommodating the photocurable resin in the hole and the recess by pressing the microlens mold having the recess on the photocurable resin, and the photocuring stored in the hole by irradiating the light. The light curable resin is cured, and the light curable resin accommodated in the recess includes a step of uncured by the light shielding film and a step of removing the uncured photo curable resin. Is a method for manufacturing a light-emitting element array chip.

According to a second aspect of the present invention, in the light emitting element array chip according to the first aspect, the concave portion has a groove shape penetrating from one end portion of the microlens mold to the other end portion. It is a manufacturing method.
The invention according to claim 3 is the method for manufacturing the light-emitting element array chip according to claim 2, wherein the recess is provided in a plurality of different directions.
The invention according to claim 4 is the method of manufacturing the light-emitting element array chip according to claim 2, wherein the removal is performed by supplying a cleaning liquid to the recess and cleaning the recess.
The invention according to claim 5 is characterized in that the recess is formed at a position corresponding to a position of a bonding pad of the light emitting element array chip when the microlens mold is pressed against the photocurable resin. The method of manufacturing a light emitting element array chip according to claim 1.
The invention according to claim 6 is characterized in that the concave portion is formed at a position corresponding to an end portion of the wafer on which the light emitting element is formed when the microlens mold is pressed against the photocurable resin. A method for manufacturing a light-emitting element array chip according to claim 1.
The invention according to claim 7 is the light emitting element array chip manufacturing method according to claim 1, wherein the light emitting element array chip is a self-scanning light emitting element array chip.

  According to an eighth aspect of the present invention, a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and an outer peripheral region of the hole, a light shielding film is formed on the bottom. A microlens mold having a concave portion.

  The invention according to claim 9 is the microlens mold according to claim 8, wherein the recess penetrates from one end of the substrate to the other end.

  The invention according to claim 10 has a light emitting element array in which a plurality of light emitting element array chips are arranged in the main scanning direction, and an optical element that forms an image of the light output of the light emitting element array, and the light emitting element array The chip is a micro having a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and a recess formed in the outer peripheral region of the hole and having a light shielding film formed on the bottom. The lens mold is pressed against the photocurable resin, irradiated with light to cure the photocurable resin contained in the portion where the light shielding film is not formed on the microlens mold, and the microlens mold A light-emitting element head comprising a light-emitting element having a microlens in a light-emitting element by removing the photocurable resin contained in a portion where a light-shielding film is formed as uncured A.

  The invention according to claim 11 includes a toner image forming unit that forms a toner image, a transfer unit that transfers the toner image to a recording medium, and a fixing unit that fixes the toner image to the recording medium. The toner image forming means includes a substrate, a plurality of holes having a transfer shape in the shape of a microlens formed on the surface of the substrate, a recess formed in the outer peripheral region of the hole and having a light shielding film formed on the bottom. The microlens molding die having a pressure is pressed against the photocurable resin, irradiated with light to cure the photocurable resin accommodated in the portion where the light shielding film is not formed on the microlens molding die, and the microlens The photo-curable resin accommodated in the portion of the mold where the light-shielding film is formed is provided with a light-emitting element head in which a microlens is formed on the light-emitting element by removing it as uncured. An image forming apparatus.

According to the first aspect of the present invention, the microlens is molded by using the microlens molding die provided with the concave portion in which the light shielding film is formed at the bottom, thereby suppressing the protrusion of the resin, and releasing the microlens molding die. A method of manufacturing a light emitting element array chip excellent in performance can be realized.
According to the invention of claim 2, since the recess is formed in a groove shape penetrating from one end of the microlens mold to the other end, the releasability of the microlens mold is improved, so that the production is more A method for manufacturing a light emitting element array chip with high performance can be realized.
According to invention of Claim 3, the manufacturing method of the light emitting element array chip | tip which was further excellent in the mold release property of a microlens shaping | molding die is realizable by providing a recessed part in several different directions.
According to the invention of claim 4, since the photocurable resin can be removed more easily by supplying the cleaning liquid to the recesses and cleaning the recesses, a method for manufacturing a light-emitting element array chip with higher productivity can be realized. .
According to the invention of claim 5, by providing the concave portion at a position corresponding to the bonding pad, it is possible to realize a method of manufacturing a light emitting element array chip in which no photocurable resin remains at the position of the bonding pad.
According to the sixth aspect of the present invention, since the concave portion is provided at a position corresponding to the end portion of the wafer on which the light emitting element is formed, this portion becomes the mold release start point. A more excellent light emitting element array chip manufacturing method can be realized.
According to the invention of claim 7, a smaller light emitting element array chip can be manufactured by using the light emitting element array chip as a self-scanning light emitting element array chip.
According to the invention of claim 8, by providing the recess having the light shielding film formed at the bottom, it is possible to suppress the protrusion of the resin when the microlens is molded, and the microlens molding excellent in releasability. A mold can be realized.
According to the ninth aspect of the present invention, a microlens mold that is more excellent in releasability can be realized by forming the recess into a groove shape penetrating from one end of the substrate to the other end.
According to the tenth aspect of the present invention, since a microlens with higher accuracy can be formed, a light emitting element head having a higher light output intensity can be realized.
According to the eleventh aspect of the present invention, since the light emitting element head having higher light output intensity is provided as compared with the case where this configuration is not adopted, an image forming apparatus having higher image quality can be realized.

  Embodiments of the present invention will be described below. However, the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist. Further, the drawings used are used for explaining the present embodiment, and do not represent actual sizes.

FIG. 1 is a diagram illustrating an overall configuration of an image forming apparatus to which the exemplary embodiment is applied.
An image forming apparatus 1 shown in FIG. 1 is an image forming apparatus generally called a tandem type, and performs image formation corresponding to gradation data of each color, and image output control for controlling the image process system 10. An image processing unit (IPS: Image Processing) that is connected to a unit 30, for example, a personal computer (PC) 2 or an image reading device (IIT: Image Input Terminal) 3, and performs predetermined image processing on image data received from these units System) 40.

  The image processing system 10 includes an image forming unit 11 as an example of a toner image forming unit including a plurality of engines arranged in parallel at a constant interval in the horizontal direction. The image forming unit 11 is composed of four image forming units 11Y, 11M, 11C, and 11K of yellow (Y), magenta (M), cyan (C), and black (K). A photosensitive drum 12 that is an image carrier (photosensitive member) that forms an image by forming an image, a charger 13 that uniformly charges the surface of the photosensitive drum 12, and a photosensitive drum that is charged by the charger 13. The light emitting device head 14 is a light emitting device that exposes a light source 12, and a developing device 15 that develops a latent image obtained by the light emitting device head 14. Further, the image process system 10 multiplex-transfers each color toner image formed on the photosensitive drum 12 of each image forming unit 11Y, 11M, 11C, 11K onto a recording sheet as an example of a recording medium. A sheet conveying belt 21 that conveys the recording sheet, a driving roll 22 that is a roll for driving the sheet conveying belt 21, and a transfer roll 23 as an example of a transfer unit that transfers the toner image on the photosensitive drum 12 to the recording sheet are provided. Yes.

  Image signals input from the PC 2 or IIT 3 are subjected to image processing by the image processing unit 40 and supplied to the image forming units 11Y, 11M, 11C, and 11K through the interface. The image process system 10 operates based on a control signal such as a synchronization signal supplied from the image output control unit 30. First, in the yellow image forming unit 11Y, an electrostatic latent image is formed by the light emitting element head 14 on the surface of the photosensitive drum 12 charged by the charger 13 based on the image signal obtained from the image processing unit 40. . A yellow toner image is formed on the formed electrostatic latent image by the developing device 15, and the formed yellow toner image is transferred to a recording sheet on a sheet conveying belt 21 that rotates in the direction of the arrow in the figure. 23 is transferred. Similarly, magenta, cyan, and black toner images are formed on the respective photosensitive drums 12 and are multiple-transferred onto the recording paper on the paper transport belt 21 using the transfer roll 23. The multiple transferred toner image on the recording paper is conveyed to a fixing device 24 as an example of a fixing unit, and is fixed on the recording paper by heat and pressure.

  FIG. 2 is a diagram illustrating a configuration of the light emitting element head 14 to which the exemplary embodiment is applied. The light emitting element head 14 supports a light emitting element array 51 in which a large number of LEDs are arranged as recording elements (light emitting elements), and a print on which a circuit for controlling the driving of the light emitting element array 51 is formed. The substrate 52 includes a SELFOC lens array (SLA: registered trademark) 53 that is an optical element that forms an image of the light output emitted from each LED on the photosensitive drum 12, and the printed circuit board 52 and the SELFOC lens array 53 include: It is held by the housing 54. The light emitting element array 51 includes LEDs arranged in the number of pixels in the main scanning direction. For example, when the A3 size short (297 mm) is used as the main scanning direction, 7040 LEDs are arranged every 42.3 μm at a resolution of 600 dpi. In the present embodiment, the LEDs are arranged in a straight line, and in fact, 7680 LEDs are arranged in consideration of a side registration shift or the like.

FIG. 3 is a schematic diagram illustrating the structure of the light emitting element array 51.
In the light emitting element array 51 shown in FIG. 3, a plurality of light emitting element array chips 100 are arranged in a staggered pattern in the main scanning direction.
The light emitting element array chip 100 has a rectangular shape and includes bonding pads 101 which are spaces for wiring and the like on both sides. By providing the bonding pad 101 in this way, there is an advantage that the chip width can be reduced to a width almost required by the bonding pad 101 itself.
In the region between the bonding pads 101 on both sides of the light emitting element array chip 100, the LEDs 102 as light emitting elements are arranged linearly at equal intervals along the long side of the rectangle in the main scanning direction. Here, the LED 102 is arranged close to one of the long sides of the light emitting element array chip 100. The odd-numbered light-emitting element array chip 100 and the even-numbered light-emitting element array chip 100 are arranged so that the LEDs 102 face each other and the bonding pads 101 are overlapped. With this arrangement, all the LEDs 102 can be arranged at equal intervals in the main scanning direction.
A microlens 103 (not shown) is attached on each LED 102.

4A and 4B are diagrams illustrating the structure of the light emitting element array chip 100. FIG.
FIG. 4A is a view of the light emitting element array chip 100 as seen from the direction in which the light of the LED 102 is emitted. Moreover, FIG.4 (b) is AA sectional drawing of Fig.4 (a).
As described above, the bonding pads 101 are arranged on both sides of the light emitting element array chip 100, and the LEDs 102 are arranged linearly at equal intervals in a region sandwiched between the bonding pads 101 on both sides. Each LED 102 is formed with a microlens 103 on the light emitting side. The microlens 103 condenses the light emitted from the LED 102 and can efficiently make the light incident on the photosensitive drum 12 (see FIG. 2).
The microlens 103 is made of a transparent resin such as a photocurable resin, and the surface thereof preferably has an aspherical shape in order to collect light more efficiently. Further, the size, thickness, focal length, and the like of the microlens 103 are appropriately determined depending on the wavelength of the LED 102 used, the refractive index of the photocurable resin used, and the like.

  In the present embodiment, it is preferable to use a self-scanning light emitting element array as the light emitting element array chip 100. The self-scanning light-emitting element array uses a light-emitting thyristor having a pnpn structure as a constituent element of the light-emitting element array, and is configured to realize self-scanning of the light-emitting element. No. 2-14584, JP-A-2-92650, and JP-A-2-92651. Japanese Patent Application Laid-Open No. 2-263668 discloses a self-scanning light emitting element array having a structure separated from a light emitting element array as a light emitting part using the transfer element array as a transfer part.

FIG. 5 is an equivalent circuit diagram of a self-scanning light emitting element array of a separate type. This self-scanning light emitting element array includes transfer thyristors T ₁ , T ₂ , T ₃ ,... And write light emitting thyristors L ₁ , L ₂ , L ₃ ,. The configuration of the transfer unit uses a diode connection. V _GK is a power supply (usually 5 V), and is connected to the gate electrodes G ₁ , G ₂ , G ₃ ,... Of each transfer thyristor through the load resistance _RL from the power line 72. Further, the gate electrodes G ₁ , G ₂ , G ₃ ,... Of the transfer thyristor are also connected to the gate electrode of the write light-emitting thyristor. The gate electrode of the transfer thyristor T ₁ is the start pulse phi _S is applied to the anode electrode of the transfer thyristor, transfer clock pulses φ1 alternately, .phi.2 is applied. These clock pulses φ 1 and φ 2 are supplied via clock pulse lines 74 and 76. The anode electrode of the write light emitting thyristor, via a signal line 78, a write signal phi _I is added.

Next, the operation will be briefly described. First voltage of the transfer clock pulses φ1 to the transfer thyristor T ₂ at the high level is on. At this time, the potential of the gate electrode _{G 2} is lowered to approximately 0V from 5V to _{V GK.} The effect of this potential drop is transmitted by the diode D ₂ to the gate electrode G _3, it is set to the potential of about 1V (forward threshold voltage of the diode D ₂ (equal to the diffusion potential)). However, the connection of the potential of the gate electrode G ₁ for the diode D ₁ is reverse biased state is not performed, the potential of the gate electrode G ₁ remains at 5V. ON potential of the light-emitting thyristor, since is approximated by a diffusion potential of the gate electrode potential + pn junction (approximately 1V), to the H-level voltage of the next transfer clock pulse φ2 for turning on the approximately 2V (the transfer thyristor T ₃ required voltage) or more and and about 4V (only the transfer thyristor T ₃ by setting the voltage) or less necessary to turn on the transfer thyristor T ₄ is turned on, other than the transfer thyristor off Can be left. Therefore, the ON state is transferred by two transfer clock pulses.

The start pulse φ _S is a pulse for starting such a transfer operation. At the same time, the start pulse φ _{S is set} to L level (about 0 V), and at the same time, the transfer clock pulse φ 2 is set to H level (about 2 to about 4 V). , to turn on the transfer thyristor _{T 1.} Shortly thereafter, a start pulse φ _S is returned to the H level.

Assuming that the transfer thyristor T ₂ is in the ON state, the potential of the gate electrode G ₂ is, lower than V _{GK (here} assumed to 5V), becomes substantially 0V. Accordingly, the voltage of the write signal phi _I is, if the diffusion potential of the pn junction (approximately 1V) above, it is possible to write for the light-emitting thyristors L ₂ and the light-emitting state.

In contrast, the gate electrode _{wherein G 1} is about 5V, the gate electrode _{G 3} are approximately 1V. Accordingly, the write voltage of the write light-emitting thyristor L ₁ of about 6V, the write voltage of the write light-emitting thyristor L ₃ is about 2V. Now, the voltage of the write signal phi _I can write only to the write light-emitting thyristor _{L 2} is a range of 1 to 2 V. When the write light-emitting thyristor L ₂ is turned on, i.e., enters the emission state, the light emission intensity is decided to the amount of current flowing to the write signal phi _I, it is possible to image writing at any intensity. Further, in order to transfer the light-emitting state to the next light emitting element is dropped to 0V the voltage of the write signal phi _I line once, it is necessary to once turn off the light-emitting element that emits light.

Next, a method for forming the light emitting element array chip 100 by forming the microlens 103 on the LED 102 will be described.
FIGS. 6A to 6F and FIGS. 7A to 7E are diagrams illustrating a process of forming the light emitting element array chip 100 by forming the microlens 103 on the LED 102.
This process is roughly divided into a process of creating a microlens mold 200 (FIGS. 6A to 6F) for forming the microlens 103, and the microlens mold 200 is actually used. The process includes forming the microlens 103 and forming the light emitting element array chip 100 (FIGS. 7A to 7E).

First, the process of creating the microlens mold 200 will be described.
First, a recess 202 is formed in a substrate 201 made of quartz glass (FIG. 6A). The recess 202 can be created by mechanical processing.

  Next, a chromium film 203 is formed on the substrate 201 in which the concave portion 202 is formed. The chromium film 203 can be formed by a method such as vapor deposition, and the thickness is preferably about 0.2 μm to 1 μm. At this time, the chromium film 203 is also formed on the entire surface of the substrate 201 and the bottom of the recess 202 (FIG. 6B).

  Next, an opening 204 is provided in the chromium film 203 (FIG. 6C). The interval between the central portions of the openings 204 is the same as the interval between the central portions of the microlenses 103 (see FIG. 4), and can be set to, for example, about 42.3 μm. The opening 204 can be provided by a photolithography method. That is, a resist layer corresponding to the opening 204 is formed, and a portion corresponding to the opening 204 of the chromium film 203 is removed by dry etching or wet etching using the resist layer as a mask. As dry etching, reactive ion etching (RIE) or inductively coupled plasma etching can be used. As wet etching, a method of immersing in dilute hydrochloric acid or dilute sulfuric acid can be used. Then, when the remaining resist layer is removed by using a resist removing solution or the like, an opening 204 is formed.

  Next, wet etching of the substrate 201 is performed. As the etchant, a hydrofluoric acid aqueous solution or the like can be used. At this time, the chromium film 203 functions as a mask, and the portion of the opening 204 is isotropically etched. As a result, a substantially hemispherical hole 205 is formed in the quartz glass substrate 201 (FIG. 6D). The shape of the substantially hemispherical hole 205 is a transfer shape of the microlens 103.

Next, the chromium film 203 is partially removed (FIG. 6E). For the removal of the chromium film 203, a dry etching method such as the above-described reactive ion etching (RIE) or inductively coupled plasma etching method or a wet etching method in which the film is immersed in dilute hydrochloric acid or dilute sulfuric acid can be used. For example, it can also be removed by applying an adhesive tape and peeling it off.
Then, when the microlens 103 is formed, a mold release process is performed in order to improve the mold releasability from the microlens mold 200 (FIG. 6F).
This mold release treatment can be performed, for example, by a method in which a mold release film 207 is formed by coating a fluororesin such as Teflon (registered trademark). Further, it is preferable to form a spacer (not shown) for defining the microlens mold 200 at a predetermined position when the microlens 103 is formed. The spacer can be formed, for example, by applying one layer of spherical beads made of plastic or the like and having a particle size of around 10 μm.
The microlens mold 200 can be created through such a series of steps.

Next, the process of creating the microlens 103 using the microlens mold 200 created as described above will be described.
First, a photocurable resin 302 that is cured by ultraviolet (UV) is dropped onto the LED wafer 301 on which the bonding pads 101 and the LEDs 102 are formed (FIG. 7A). At this time, it is preferable to make the photocurable resin 302 uniform on the LED wafer 301 by performing spin coating or the like. The photocurable resin 302 to be used is not particularly limited as long as it transmits the light emitted from the LED 102, but a general epoxy-based photocurable resin or an acrylic photocuring is used. Resin can be used.

Next, the photocurable resin 302 is developed by pressing the microlens mold 200 against the LED wafer 301, and fine alignment is performed in the horizontal direction and the thickness direction (FIG. 7B). At this time, the photocurable resin 302 enters the hole 205 formed in the microlens mold 200 and becomes the shape of the microlens 103.
The photocurable resin 302 that cannot be accommodated in the hole 205 is accommodated in the recess 202. Thus, by accommodating the excess photocurable resin 302 in the recessed part 202, the protrusion of the photocurable resin 302 can be suppressed. At this time, it is preferable from the viewpoint of suppressing the protrusion of the photocurable resin 302 that the recess 202 is not filled with all of the photocurable resin 302 and an extra space is generated.
The alignment in the thickness direction can be performed by pressing the microlens mold 200 against the LED wafer 301 with a predetermined pressure and bringing the LED wafer 301 into contact with a spacer (not shown). The position in the thickness direction of the microlens mold 200 is defined by a spacer, and the thickness of the photocurable resin 302 can be made uniform as a whole. Therefore, the focal lengths of the formed microlenses 103 are also uniform. Further, the alignment in the horizontal direction can be performed by a method of aligning with a predetermined marker (not shown).

After the alignment of the microlens mold 200 is completed, the ultraviolet ray is irradiated to cure the photocurable resin 302. At this time, the portion of the chromium film 203 functions as a light shielding film, the ultraviolet rays are shielded, and the photocurable resin 302 below the chromium film 203 remains uncured (FIG. 7C).
Here, it is sufficient that the photocurable resin 302 is uncured as long as it is not cured to the extent that it can be removed by washing in the subsequent step of FIG. 7E, and curing is not progressing at all. It does not mean that.

  After the photocurable resin 302 is cured, the microlens mold 200 is released (FIG. 7D). Then, when the photocurable resin 302 that has not been cured is removed by washing and the LED wafer 301 is diced, the light emitting element array chip 100 in which the microlens 103 made of the photocurable resin 302 cured on the LED 102 is formed. Can be manufactured (FIG. 7E).

Here, the concave portion 202 described above will be described in more detail.
FIGS. 8A and 8B are diagrams illustrating a first example of the recess 202.
The process shown in FIGS. 8A and 8B corresponds to the process shown in FIG. 7B described above. The microlens mold 200 is pressed against the LED wafer 301 on which a large number of LEDs 102 are formed, and a photocurable resin 302 is obtained. FIG. 6 is an overall view of a process of forming the shape of the microlens 103. 8A is a view of the microlens molding die 200 as viewed from the direction in which it is pressed against the LED wafer 301, and FIG. 8B is a cross-sectional view taken along the line BB of FIG. 8A.

  In this process, the LED 102 is already formed on the LED wafer 301. Further, in the microlens mold 200, a plurality of recesses 202 having a groove shape are formed in parallel to the vertical direction in FIG. The position where the concave portion 202 is formed in the microlens mold 200 is not formed at a position corresponding to the position of the LED 102 on the LED wafer 301 but is formed at a position corresponding to the position of the bonding pad 101. The recess 202 is formed so as to penetrate from one end of the microlens mold 200 to the other end.

  When the microlens mold 200 is pressed against the LED wafer 301, the photocurable resin 302 penetrates into the hole 205 formed in the microlens mold 200 as described in FIG. The photo-curable resin 302 that is accommodated in the hole 205 and cannot be accommodated in the hole 205 is accommodated in the recess 202. Then, as described in FIG. 7C, ultraviolet rays are then irradiated to cure the photocurable resin 302. However, since the groove-shaped recess 202 has a chromium film 203 as a light shielding film at its bottom, The light is not irradiated and the photocurable resin 302 becomes uncured. Therefore, although the micro lens 103 (refer FIG.7 (e)) is formed in the part of LED102, uncured photocurable resin 302 can be removed in another part. Since the position of the groove-shaped recess 202 corresponds to the position of the bonding pad 101 of the LED wafer 301, the photocurable resin 302 does not remain at the position of the bonding pad 101, and this portion is exposed. Can do.

The removal of the photocurable resin 302 may be performed after the microlens mold 200 is released as shown in FIG. 7E, but can also be performed before the mold release. That is, a cleaning liquid can be supplied to the groove-shaped recess 202, and the uncured photocurable resin 302 can be removed by the cleaning liquid. Specifically, it is immersed in a washing tank (not shown) containing an organic solvent such as ethanol or isopropyl alcohol (IPA) and rocked. Since the concave portion 202 has a through-groove shape, the cleaning liquid enters from the end portion of the concave portion 202 so that the concave portion 202 can be cleaned.
When cleaning is performed before the mold release in this manner, the portion where the uncured photocurable resin 302 was present in the concave portion 202 becomes a void, and the microlens molding die 200 can be released more easily. it can.

FIGS. 9A to 9B are diagrams illustrating a second example of the recess 202.
The process shown in FIGS. 9A to 9B corresponds to the above-described FIG. 7B as in the case described with reference to FIGS. 8A to 8B, and an LED wafer on which a large number of LEDs 102 are formed. FIG. 3 is an overall view of a process of pressing a microlens molding die 200 against 301 to make a photocurable resin 302 into the shape of a microlens 103. 9A is a view of the microlens molding die 200 as viewed from the direction in which the microlens mold 200 is pressed against the LED wafer 301, and FIG. 9B is a cross-sectional view taken along the line CC in FIG. 9A.

  In the steps shown in FIGS. 9A to 9B, the concave portion 202 is formed at a position corresponding to the end portion of the LED wafer 301 of the microlens mold 200, as compared with the case shown in FIGS. Is further provided. The recess 202 is preferably formed so as to cover the end of the LED wafer 301. By providing the concave portion 202 in this manner, the photocurable resin 302 in this portion becomes uncured and can be removed by washing. When mold release is performed with the photocurable resin 302 removed at the end of the LED wafer 301, this part becomes the mold release start point, and the mold release of the microlens mold 200 can be performed more easily.

10A to 10B are diagrams illustrating a third example of the recess 202. FIG.
The process shown in FIGS. 10A to 10B corresponds to the above-described FIG. 7B, as in the case described with reference to FIGS. 8A to 8B, and an LED wafer on which a large number of LEDs 102 are formed. FIG. 3 is an overall view of a process of pressing a microlens molding die 200 against 301 to make a photocurable resin 302 into the shape of a microlens 103. 10A is a view of the microlens molding die 200 as viewed from the direction in which the microlens mold 200 is pressed against the LED wafer 301, and FIG. 10B is a cross-sectional view taken along the line DD in FIG. 10A.

10 (a) to 10 (b), a groove-shaped recess 202 is formed in the vertical direction in FIG. 10 (a) with respect to the microlens mold 200 shown in FIGS. 9 (a) to 9 (b). In addition to being provided, a groove-shaped recess 202 is also provided in the lateral direction.
When the recesses 202 are provided in a plurality of different directions as described above, the recesses 202 are cleaned before release, and the uncured photo-curable resin 302 is removed, thereby further increasing the number of portions that become voids. . Therefore, since the contact area between the photocurable resin 302 and the LED wafer 301 can be further reduced, the releasability of the microlens mold 200 can be further improved.

1 is a diagram illustrating an overall configuration of an image forming apparatus to which the exemplary embodiment is applied. It is the figure which showed the structure of the light emitting element head to which this Embodiment is applied. It is the schematic explaining the structure of the light emitting element array. It is a figure explaining the structure of the light emitting element array chip. It is an equivalent circuit diagram of a self-scanning light emitting element array of a separation type. It is a figure explaining the process of creating the microlens shaping | molding die for forming a microlens. It is the figure explaining the process of forming a microlens using a microlens shaping | molding die and creating a light emitting element array chip. It is a figure explaining the 1st example of a crevice. It is a figure explaining the 2nd example of a crevice. It is a figure explaining the 3rd example of a crevice.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 11K, 11C, 11M, 11Y ... Image forming unit, 14 ... Light emitting element head, 23 ... Transfer roll, 24 ... Fixing device, 51 ... Light emitting element array, 53 ... Selfoc lens array, 100 ... Light emission Element array chip, 101 ... bonding pad, 102 ... LED, 103 ... microlens, 200 ... microlens mold, 201 ... substrate, 202 ... recess, 203 ... chrome film, 205 ... hole, 301 ... LED wafer, 302 ... Photo curable resin

Claims (11)

A microlens mold having a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and a recess formed in the outer peripheral region of the hole and having a light shielding film formed on the bottom By pressing the photocurable resin into the hole and the recess,
Irradiating light, curing the photocurable resin accommodated in the hole, and making the photocurable resin accommodated in the recess uncured by the light shielding film;
Removing the uncured photocurable resin;
A method for manufacturing a light-emitting element array chip, comprising: forming a microlens on the light-emitting element.   2. The method of manufacturing a light emitting element array chip according to claim 1, wherein the concave portion has a groove shape penetrating from one end portion of the microlens mold to another end portion.   The method of manufacturing a light emitting element array chip according to claim 2, wherein the recess is provided in a plurality of different directions.   The method of manufacturing a light emitting element array chip according to claim 2, wherein the removal is performed by supplying a cleaning liquid to the concave portion and cleaning the concave portion.   2. The light emitting device according to claim 1, wherein the concave portion is formed at a position corresponding to a position of a bonding pad of the light emitting element array chip when the microlens mold is pressed against the photocurable resin. A method for manufacturing an element array chip.   The said recessed part is formed in the position corresponding to the edge part of the wafer in which the said light emitting element was formed, when pressing the said microlens shaping | molding die to the said photocurable resin. Manufacturing method of light emitting element array chip.   The method of manufacturing a light emitting element array chip according to claim 1, wherein the light emitting element array chip is a self-scanning light emitting element array chip. A substrate,
A plurality of holes formed on the surface of the substrate and having a microlens-shaped transfer shape;
A recess formed in the outer peripheral region of the hole and having a light shielding film formed on the bottom;
A microlens molding die comprising:   The microlens molding die according to claim 8, wherein the recess penetrates from one end of the substrate to the other end. A light emitting element array in which a plurality of light emitting element array chips are arranged in the main scanning direction;
An optical element for imaging the light output of the light emitting element array,
The light emitting element array chip is:
A microlens mold having a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and a recess formed in the outer peripheral region of the hole and having a light shielding film formed on the bottom Is pressed against the photocurable resin, and the photocurable resin contained in the portion where the light shielding film is not formed on the microlens mold is cured by irradiating light, and the light shielding film of the microlens mold is formed. A light-emitting element head comprising: a light-emitting element having a microlens in a light-emitting element by removing the photocurable resin contained in a formed portion as uncured. Toner image forming means for forming a toner image;
Transfer means for transferring the toner image to a recording medium;
Fixing means for fixing the toner image to a recording medium,
The toner image forming unit includes:
A microlens mold having a substrate, a plurality of holes formed on the surface of the substrate and having a transfer shape in the shape of a microlens, and a recess formed in the outer peripheral region of the hole and having a light shielding film formed on the bottom Is pressed against the photocurable resin, irradiated with light to cure the photocurable resin contained in the portion where the light shielding film is not formed on the microlens molding die, and the light shielding film of the microlens molding die is An image forming apparatus comprising: a light emitting element head in which a microlens is formed on a light emitting element by removing the photocurable resin contained in a formed portion as uncured.

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