JP2016206498A - Lens formation method, photomask and light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a lens by significantly reducing lens formation steps.SOLUTION: A negative type lens formation material is formed on one surface of a substrate, an exposure device performs exposure via a photomask formed with a mask pattern for lens formation on a pattern formation region in a shape corresponding to a lens outer shape, a lens is formed on a light-emitting element with development, and a mask pattern 37 having a lens apex formation transmission part 37AX, a transmission part, a light shielding part 37B, and a lens outer shape formation transmission part 37AY with a prescribed width provided along a region edge is formed in the pattern formation region of the photomask. With this configuration, a columnar lens can be formed on the light-emitting element on the one surface of the substrate by preventing the interior of the lens from being inclined so as to separate from the lens apex portion by a lens outer shape part with the material formation step, exposure step and development step with one photolithography, and the lens can be easily formed by significantly reducing the lens formation steps.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a lens forming method, a photomask, and a light emitting device, for example, a lens forming method for forming microlenses on a plurality of light emitting elements of a display module provided in a projection display device, and a method for forming a plurality of microlenses. And a photomask and a microdisplay having a plurality of light emitting elements and a microlens formed on the light emitting elements.

  In the conventional display module, a plurality of microlenses for improving light utilization efficiency are formed on a plurality of light emitting elements arranged in a matrix on one surface of a substrate. In the conventional lens forming procedure for actually forming a plurality of microlenses on a substrate, first, a dry film resist is formed on the substrate with a predetermined thickness in a first lens forming step by a photolithography technique, and a second lens is formed. In the step, the dry film resist is exposed, and in the third lens forming step, the dry film resist is developed to form first lens columns on each of the plurality of light emitting elements. Next, in the lens formation procedure, the negative resist is transferred onto the substrate and the plurality of first lens columns in the fourth lens formation step by a photolithography technique, and heat treatment is performed at a predetermined temperature, whereby the plurality of first The lens support is covered with a negative resist, the negative resist is exposed in the fifth lens forming step, the negative resist is developed in the sixth lens forming step, and the upper portions of the plurality of first lens posts are curved. Two lens struts are formed. Subsequently, in the lens forming procedure, a negative resist is transferred onto the substrate, the plurality of first lens columns, and the plurality of second lens columns in the seventh lens forming process by a photolithography technique, and heat treatment is performed at a predetermined temperature. As a result, the first lens column and the plurality of second lens columns are covered with a negative resist so that the upper portion of the second lens column is deformed into a curved surface in the negative resist, thereby forming an eighth lens. In the step, the negative resist is exposed, and in the ninth lens forming step, the negative resist is developed to form columnar microlenses that respectively cover the first lens column and the second lens column at the positions where the plurality of light emitting elements are arranged. (For example, see Patent Document 1).

JP 2013-11803 A (page 9 to page 12, FIGS. 1-1 and 1-2)

  However, in the conventional lens forming procedure, the first lens column and the second lens column are sequentially stacked on the substrate through the first to ninth lens forming steps by photolithography three times, and further, Since the microlens is formed so as to cover the first lens support and the second lens support, there are many lens forming processes, and there is a problem that the microlens cannot be easily formed.

  The present invention has been made in consideration of the above points, and an object of the present invention is to propose a lens forming method, a photomask, and a light emitting device capable of easily forming a lens by dramatically reducing the lens forming process.

  In order to solve such a problem, in the present invention, in a lens forming method for forming a columnar lens on a light emitting element mounted on one surface of a substrate, a negative lens forming material so as to cover the light emitting element on one surface of the substrate. And using an exposure apparatus, the lens forming material on one surface of the substrate is exposed through a photomask in which a lens forming mask pattern is formed in a pattern forming region having a shape corresponding to the lens outer shape, The lens forming material exposed on one surface of the substrate is developed to form a lens on the light-emitting element, and the lens apex forming transmission provided at a predetermined position with respect to the pattern forming area is used for exposure of the lens forming material. A mask pattern that includes a transmission part and a light shielding part provided around the lens vertex forming transmission part, and a lens outer shape formation transmission part having a predetermined width provided along the edge of the region. There was to use a photomask formed.

  Therefore, in the present invention, the lens forming portion prevents the inside of the lens from being inclined away from the lens apex portion on the light emitting element on one surface of the substrate by a single photolithography material forming process, exposure process and developing process. Thus, a columnar lens can be formed.

  According to the present invention, in a lens forming method for forming a columnar lens on a light emitting element mounted on one surface of a substrate, a negative lens forming material is formed on the one surface of the substrate so as to cover the light emitting element, and exposure is performed. Using the apparatus, the lens forming material on one surface of the substrate is exposed through a photomask in which a lens forming mask pattern is formed in a pattern forming region having a shape corresponding to the lens outer shape. The exposed lens forming material is developed to form a lens on the light-emitting element, and the lens apex forming transmission portion provided at a predetermined position with respect to the pattern forming region for exposure of the lens forming material, and the lens A photomask on which a mask pattern having a transmissive part and a light shielding part provided around a vertex forming transmissive part and a lens outer shape forming transmissive part having a predetermined width provided along a region edge is formed. By using it, the material formation process by one photolithography, the exposure process, and the development process can prevent the lens inside from being tilted away from the lens apex portion by the lens outer shape portion on the light emitting element on one surface of the substrate. A columnar lens can be formed, and thus a lens forming method, a photomask, and a light emitting device that can easily form a lens by dramatically reducing the lens forming step can be realized.

It is a rough-line perspective view which shows the structure of the display module by 1st Embodiment. It is a block diagram which shows the equivalent circuit of a display module. It is a rough-line top view which shows the structure (1) of a LED micro display. It is an approximate line sectional view showing composition (2) of a LED micro display. It is a rough-line top view which shows the structure of a photomask. It is a rough-line top view which shows the structure of the lens unit mask pattern formed in the photomask. It is a rough-line top view which shows a LED formation procedure. It is an approximate line sectional view showing a lens formation procedure. It is a rough-line perspective view which shows the structure of the display module by 2nd Embodiment. It is a rough-line top view which shows the structure (1) of a LED micro display. It is an approximate line sectional view showing composition (2) of a LED micro display. It is a rough-line top view which shows the structure of the lens unit mask pattern formed in the photomask. It is a rough sectional drawing used for description of the micro lens formed on LED of one surface of a board | substrate by the lens formation procedure. It is a rough-line top view which shows the structure (1) of the lens unit mask pattern of the photomask by other embodiment. It is a rough-line top view which shows the structure (2) of the lens unit mask pattern of the photomask by other embodiment. It is a rough-line top view which shows the structure (3) of the lens unit mask pattern of the photomask by other embodiment. It is a rough sectional drawing used for description of the micro lens formed on LED of one surface of a board | substrate by the lens formation procedure. It is a rough-line top view which shows the structure (4) of the lens unit mask pattern of the photomask by other embodiment. It is a rough sectional drawing used for description of the micro lens formed on LED of one surface of a board | substrate by the lens formation procedure. It is an approximate line sectional view showing the lens formation procedure by other embodiments.

The best mode for carrying out the invention (hereinafter, also referred to as an embodiment) will be described below with reference to the drawings. The description will be given in the following order.
(1) First embodiment (2) Second embodiment (3) Other embodiments

(1) First Embodiment (1-1) Configuration of Display Module In FIG. 1, reference numeral 1 denotes a display module according to the first embodiment as a whole. The display module 1 is provided in a projection display device (not shown), and is a self-luminous thin film semiconductor light emitting element, for example, a plurality of LEDs (Light Emitting Diodes) and projection by a plurality of cylindrical microlenses. An image for display is formed. Incidentally, the microlens is, for example, a minute lens having a lens diameter of about several [μm] to several hundred [μm]. In the display module 1, an LED microdisplay 3 including a plurality of LEDs and a plurality of microlenses is formed on one surface 2A of the substrate 2, and a drive circuit 4 for driving the plurality of LEDs of the LED microdisplay 3 is provided. Has been implemented. In the display module 1, one end of a cable 5 such as a flexible flat cable is fixed to one surface 2 </ b> A of the substrate 2, and a predetermined wiring pattern (not shown) having a plurality of electrodes is formed. As a result, the display module 1 has the driving circuit 4 electrically connected to the plurality of LEDs of the LED micro display 3 on the one surface 2A of the substrate 2 through the wiring pattern, and one end of the cable 5 is connected to the driving circuit 4. It is electrically connected via a wiring pattern. In the display module 1, the other end of the cable 5 is electrically connected to, for example, a control circuit (not shown) of the projection display device. Incidentally, the substrate 2 is a semiconductor substrate such as Si, GaAs, GaP, InP, GaN, or ZnO, a ceramic substrate such as AlN or Al ₂ O ₃ , a glass substrate, a glass epoxy substrate, a metal substrate such as Cu or Al, or a plastic substrate. It is. In addition, when the board | substrate 2 is formed with the electroconductive material, the insulating layer is formed between 2 A of one surface and a wiring pattern, and between the said 2 A and the some LED. The substrate 2 has a heat sink (not shown) or a metal housing (not shown) attached to the other surface 2B via, for example, an insulating heat radiating sheet (not shown). The heat generated by 4 is dissipated.

  Next, an equivalent circuit of the display module 1 will be described with reference to FIG. The LED micro display 3 is formed as a passive-type m-row / k-column LED dot matrix-type display, and k anode lines 10 are arranged in parallel in the row direction, and intersect with the k anode lines 10. M cathode lines 11 are arranged in parallel in the column direction. In the LED micro display 3, the LEDs 12 are connected to the anode line 10 and the cathode line 11 at a plurality of intersections of the k anode lines 10 and the m cathode lines 11, respectively. Thereby, in the LED micro display 3, a plurality of (that is, m × k) LEDs 12 are arranged in a matrix. Incidentally, the plurality of LEDs 12 of the LED micro display 3 correspond to, for example, a plurality of pixels of the image to be displayed, and the subscripts (m, k) attached to the individual LEDs 12 in FIG. The arrangement position of the LED 12 corresponding to the coordinates of the pixel is shown. On the other hand, the drive circuit 4 is configured by connecting an anode driver 16, a first cathode driver 17, and a second cathode driver 18 to the display control unit 15. K anode lines 10 of the LED micro display 3 are connected to the anode driver 16. Further, odd-numbered cathode lines 11 among the m cathode lines 11 are connected to the first cathode driver 17 via m / 2 cathode connection wirings 20. Furthermore, the even-numbered cathode lines 11 are connected to the second cathode driver 18 via m / 2 cathode connection wires 21. Furthermore, the display control unit 15 is connected to the control circuit through the wiring pattern and the cable 5 described above. Then, the display control unit 15 analyzes the image data and the like given from the control circuit, and converts the image data into matrix data for displaying the image by individually controlling the plurality of LEDs 12 in the LED micro display 3. . That is, when the image data is composed of dot data in units of pixels that individually control the plurality of LEDs 12 arranged in a matrix, the display control unit 15 controls the dot data together with the arrangement positions of the corresponding LEDs 12. Are converted into an anode drive signal and a cathode drive signal. The display control unit 15 sends an anode drive signal to the anode driver 16 in units of image frames, and sends a cathode drive signal to the first cathode driver 17 and the second cathode driver 18. In this way, the display control unit 15 performs image display driving for the plurality of LEDs 12 of the LED micro display 3 in units of frames of the image, and also performs drive ratio (duty) control.

  Incidentally, the display control unit 15 stores, for example, a processor or composite logic circuit having a predetermined arithmetic function, a buffer for the processor or the like to exchange data with the control circuit, and data supplied from the control circuit. A timing signal generation circuit (oscillation circuit) for supplying a predetermined timing signal and a display timing signal to the storage circuit, a read timing and a write timing signal for the storage circuit, and the like. A drive signal output circuit for outputting display data obtained by reading or processing the data as an anode drive signal or a cathode drive signal, and various types of information for storing a display function or a control command given from the control circuit It consists of registers and so on. The anode driver 16 is connected to a plurality of anode lines 10 of the LED micro display 3 according to an anode drive signal (for example, light emission data indicating that the LED 12 emits light or does not emit light) given from the display control unit 15. It has a function of supplying a drive current to the row of LEDs 12. For example, the anode driver 16 has a shift register that inputs a serial anode drive signal and outputs parallel light-emission data that has been subjected to serial-parallel conversion, and a latch circuit is connected to the output side of the shift register. The latch circuit is a circuit that latches the parallel light emission data output from the shift register. A constant current circuit is connected to the output side of the latch circuit, and a plurality of anode lines 10 are connected to the output side of the constant current circuit. The first cathode driver 17 and the second cathode driver 18 have a function of scanning the rows of the LEDs 12 connected to the plurality of cathode lines 11 based on the cathode drive signal given from the display control unit 15. It is composed of a circuit or the like.

  Next, a specific configuration of the LED micro display 3 will be described with reference to FIGS. 3 and 4. Incidentally, the LED micro display 3 is configured in the same manner in each of the places where the plurality of LEDs 12 are arranged. Therefore, FIG. 3 partially shows, for example, a place where 4 × 4 LEDs 12 are arranged in a matrix in the LED micro display 3. Further, FIG. 4 shows a section where one LED 12 is arranged in the LED micro display 3 as a cross section taken along the cutting line A1-A2 shown in FIG. As shown in FIGS. 3 and 4, the LED micro display 3 includes a plurality of substantially square LEDs 12 disposed on the smoothing layer 24 provided on the one surface 2 </ b> A of the substrate 2. A cylindrical microlens 25 for light convergence is positioned and formed. In the LED micro display 3, a plurality of strip-like cathode lines 11 that are long in the row direction (lateral direction) are formed in parallel at predetermined intervals along the column direction on the smoothing layer 24 on one surface 2A of the substrate 2. In addition, a plurality of strip-like anode lines 10 that are long in the column direction (longitudinal direction) are formed so as to be insulated from the cathode lines 11 via the interlayer insulating film 26. For example, each of the plurality of LEDs 12 is formed by sequentially laminating an active layer 28 and a P-type semiconductor layer 29 at the center of the surface of an N-type semiconductor layer 27 bonded to the smoothing layer 24. The surface 29 is a light emitting region 29A. In each of the plurality of LEDs 12, the N contact electrode 11 </ b> A protruding from the cathode line 11 is in ohmic contact with the N contact portion 27 </ b> A of the N-type semiconductor layer 27. Each of the plurality of LEDs 12 is covered with an insulating layer 30 from the edge of the surface of the P-type semiconductor layer 29 around the light emitting region 29 </ b> A to the edge of the surface of the N-type semiconductor layer 27. In each of the plurality of LEDs 12, P contact electrodes 10 </ b> A protruding from the anode wires 10 are in ohmic contact with predetermined edges on the surface of the P-type semiconductor layer 29. On the other hand, each of the plurality of microlenses 25 is formed in a curved surface shape (that is, a substantially hemispherical shape) in which the lens base portion 25A is circular and the tip surface of the lens tip portion 25B protrudes with the center position as a vertex. In each of the plurality of microlenses 25, the axis passing from the apex of the lens tip 25B to the center of the lens root 25A becomes the optical axis of the microlens 25, and the optical axis on the corresponding LED 12 is approximately at the center of the light emitting region 29A. It is arranged so as to coincide with a virtual straight line perpendicular to it.

  With this configuration, the display module 1 captures image data sent from the control circuit into the display control unit 15 of the drive circuit 4. Then, in the drive circuit 4, the display control unit 15 uses, for example, a plurality of anode drive signals (that is, light emission data) for the plurality of LEDs 12 in the first row of the LED micro display 3 as serial signals according to the image data. 16 to send. When a plurality of anode drive signals are given from the display control unit 15, the anode driver 16 sequentially stores them in an internal shift register, converts them into parallel light emission data, and then latches them with a latch circuit. The anode driver 16 supplies a drive current having a predetermined value indicating whether or not the plurality of LEDs 12 emit light to the plurality of anode lines 10 of the LED micro display 3 from the constant current circuit based on the output signal and the output enable signal of the latch circuit. To do. At this time, the display control unit 15 sends a cathode drive signal to the first cathode driver 17 and the second cathode driver 18. The first cathode driver 17 and the second cathode driver 18 selectively conduct the internal select circuit with the cathode line 11 in the first row of the LED micro display 3 based on the cathode drive signal. Thereby, the LED micro display 3 supplies a drive current to the plurality of LEDs 12 in the first row via the plurality of anode lines 10 and causes the plurality of LEDs 12 to appropriately emit light according to the drive current. Then, the LED micro display 3 emits the light emitted from the plurality of LEDs 12 to the outside so as to be converged by the corresponding micro lenses 25. In addition, the display module 1 causes the drive circuit 4 and the LED micro display 3 to sequentially execute the same processing as the number of the cathode lines 11 of the LED micro display 3 (that is, the number of rows of the LEDs 12). In this way, the display module 1 generates an image based on the image data as projection image light by the plurality of LEDs 12 in the LED micro display 3 and radiates the generated projection image light through the plurality of microlenses 25. Can do.

(1-2) Manufacturing Procedure of LED Micro Display Next, a manufacturing procedure of the LED micro display 3 will be described. The manufacturing procedure of the LED micro display 3 includes an LED forming procedure for forming a plurality of LEDs 12 together with the anode lines 10 and the cathode lines 11 on the one surface 2A of the substrate 2, and a lens forming procedure for forming micro lenses 25 on the plurality of LEDs 12. Can be broadly classified. In the lens forming procedure, as will be described later, a lens forming material made of a negative transparent photosensitive resist material formed in a film shape on one surface 2A of the substrate 2 is patterned by a photolithography technique using a photomask. Thus, the microlens 25 is arranged on each of the plurality of LEDs 12. However, in the first embodiment, the process of forming the microlens 25 is selected by appropriately selecting the configuration of a mask pattern (hereinafter also referred to as a lens unit mask pattern) formed for each microlens 25 on the photomask. Is simplified. Note that the plurality of lens unit mask patterns of the photomask are for exposing a lens forming material for forming one microlens 25, respectively. Therefore, below, after explaining the structure of a photomask first, the LED formation procedure and lens formation procedure as a manufacturing procedure of LED micro display 3 are demonstrated in order.

  As shown in FIG. 5, the photomask 35 has a plurality of lens unit mask patterns 37 having the same configuration on one surface of a light transmission substrate 36 such as transparent glass, synthetic quartz, or a transparent polymer film. The matrix 2 is formed in a matrix corresponding to the arrangement positions of the plurality of microlenses 25 on the substrate 2. The photomask 35 has a light-shielding film 38 formed of a light-shielding material such as chrome or blackened metal silver on the one surface of the light-transmitting substrate 36 other than where the plurality of lens unit mask patterns 37 are formed. Incidentally, in the photomask 35 shown in FIG. 5, the hatched portion is a portion that blocks the exposure light, and the non-hatched portion is a portion that transmits the exposure light. In this case, as shown in FIG. 6, the photomask 35 corresponds to the lens outer shape of the microlens 25 on one surface of the light transmitting substrate 36 (that is, the shape (in this case, the circle) and the size (the circular shape in this case) of the lens root portion 25A). In this case, a lens unit mask pattern 37 having a plurality of transmissive portions 37A for transmitting exposure light and a plurality of light-shielding portions 37B for shielding the exposure light in a lens unit pattern formation region having a shape and size substantially equal to the diameter). Is formed. Incidentally, the plurality of light shielding portions 37B are formed in the same manner as the light shielding film 38 described above. In FIG. 6, the plurality of transmission portions 37 </ b> A are surrounded by black frames, but the black frames are not formed of a light shielding material, but are drawn for convenience in order to facilitate understanding.

  Actually, the photomask 35 has, for example, a lens unit mask pattern 37 at the center of the lens unit pattern formation region, and the lens forming material is formed by using a lens forming material at the apex of the lens tip 25B and the center of the lens root 25A ( Hereinafter, a circular transmission portion (hereinafter also referred to as a lens vertex formation transmission portion) 37AX is provided for exposure for forming these together. Further, the photomask 35 is formed as a lens unit mask pattern 37 along the region edge of the lens unit pattern forming region, and the lens forming material is used as an outer portion of the lens root portion 25A of the microlens 25 (hereinafter, this is particularly referred to as a lens outer portion). An annular transmission portion (hereinafter also referred to as a lens outer shape formation transmission portion) 37AY is provided for exposure for forming a lens shape. Further, the photomask 35 is formed as a lens unit mask pattern 37 between the lens apex forming transmitting portion 37AX and the lens outer shape forming transmitting portion 37AY in the lens unit pattern forming region, and the lens forming material is used as the lens apex portion of the microlens 25. For example, a plurality of rectangular transmission parts 37A and a rectangular or substantially triangular shape for exposure for forming a portion between the lens and the outer portion of the lens (hereinafter also referred to as a lens apex peripheral portion). A plurality of light shielding portions 37B having various shapes are provided in a predetermined pattern such as a checkered pattern.

  The sizes of the plurality of transmissive portions 37A including the lens vertex forming transmissive portion 37AX and the lens outer shape forming transmissive portion 37AY are each set as the exposure light pattern irradiated to the surface of the lens forming material. The predetermined size is selected as appropriate (that is, resolvable by the exposure apparatus). Incidentally, the size of the rectangular transmissive portion 37A among the plurality of transmissive portions 37A is the length of the shortest one of the sides, and the size of the lens apex-forming transmissive portion 37AX is the diameter, which forms the lens outer shape. The size of the transmission part 37 </ b> AY is a width along the radial direction of the lens unit mask pattern 37. The size of the plurality of light shielding portions 37B is a predetermined size that is not less than the resolution limit of the exposure apparatus and not more than the resolution limit of the lens forming material as the pattern of exposure light irradiated on the surface of the lens forming material. It is selected as appropriate. Incidentally, among the plurality of light shielding portions 37B, the size of the rectangular light shielding portion 37B is the length of the shortest side of each side, and the size of the light shielding portion 37B having another shape such as a substantially triangular shape is also included in each side. The length of the shortest side. In addition, among the plurality of transmission portions 37A including the lens vertex formation transmission portion 37AX and the lens outer shape formation transmission portion 37AY, the area of the lens vertex formation transmission portion 37AX transmits the exposure light more than the other transmission portions 37A. Appropriate selection is made to maximize the ratio.

  In addition, the width of the lens outer shape forming transmission portion 37AY is such that the portion corresponding to the lens outer shape forming transmission portion 37AY in the lens forming material (that is, the irradiation position of the exposure light that has passed through the lens outer shape forming transmission portion 37AY) is self-supporting. It is selected to have a predetermined width that can be photocured as a lens outer shape portion (and a part on the surface side of the lens forming material as an edge portion of the lens tip portion 25B) without being inclined. That is, the width of the lens outer shape forming transmission portion 37AY can be sufficiently cured so that the lens forming material is used as a lens outer shape portion and does not protrude from the curved surface of the lens front end portion 25B, and the lens root portion 25A is formed into a circular shape. It is selected to have a predetermined width that transmits a certain amount of exposure light. In the lens unit mask pattern 37, lens outer shape transmission is performed according to the type of lens forming material (that is, characteristics such as sensitivity to exposure light), the exposure amount (exposure intensity), the size of the microlens 25 to be formed, and the like. The optimum value of the width of the portion 37AY changes. For example, when the lens diameter of the microlens 25 is about 50 [μm] and the lens height is about 50 [μm], the width of the lens outer shape forming transmission portion 37AY is 1 [ When the lens diameter and the lens height are about 20 to 90 [μm], the width of the lens outer shape forming transmission portion 37AY is about 0.5 to 3 [μm]. Thus, when the lens forming material is exposed through the photomask 35, the lens unit mask pattern 37 tilts the portion corresponding to the lens apex forming transmission portion 37AX in the lens forming material as the lens apex portion. It can be photocured in a self-supporting state without any problems. Further, the lens unit mask pattern 37 is formed by inclining the portions corresponding to the plurality of fine transmitting portions 37A around the lens apex forming transmitting portion 37AX in the lens forming material so as to be attracted to the lens apex portions. Photocuring can be performed so as to form a curved surface of the lens front end portion 25B as a peripheral portion. Further, the lens unit mask pattern 37 can be photocured as a lens outer shape portion while tilting a portion corresponding to the lens outer shape forming transmission portion 37AY in the lens forming material so as to be attracted to the lens apex portion. In this way, the photomask 35 is formed such that the plurality of lens unit mask patterns 37 can expose the lens forming material for forming the cylindrical microlens 25, respectively.

  Next, an LED forming procedure and a lens forming procedure as a manufacturing procedure of the LED micro display 3 will be described in order. First, as shown in FIG. 7, in the LED forming procedure, in the first LED forming step, after the smoothing layer 24 that is an insulating layer is formed on the one surface 2 </ b> A of the substrate 2 by a predetermined method, for example, on the growth substrate (not shown). The formed plurality of LEDs 12 are separated from the growth substrate and bonded to the smoothing layer 24 on the first surface 2A of the substrate 2. Next, in the LED formation procedure, in the second LED formation step, an anode line 10 and a cathode line 11 (not particularly shown in FIG. 7) are formed on one surface 2A of the substrate 2 by a photolithography technique or the like to form a plurality of LEDs 12. Connect electrically. In this way, in the LED formation procedure, the plurality of LEDs 12 are mounted in a matrix on one surface 2A of the substrate 2. Subsequently, as shown in FIG. 8A, in the lens forming procedure, the lens forming material 40 is applied to the one surface 2A of the substrate 2 by the spin coat method or laminated in the form of a dry film in the first lens forming step. For example, a film of the lens forming material 40 is formed on the one surface 2A so as to cover the plurality of LEDs 12. Incidentally, the lens forming material 40 can be produced by using epoxy resin, acrylic resin, silicone, polyimide, polyamideimide or the like as a main material, but more preferably a material having a relatively high transmittance with respect to the emission wavelength of the LED 12. , And a material with a relatively low decrease in transmittance due to deterioration with respect to the emission wavelength.

  Next, as shown in FIG. 8B, in the lens forming procedure, in the second lens forming step, a predetermined exposure apparatus (extra high pressure mercury lamp, high pressure mercury lamp, metal halide lamp, deep ultraviolet lamp or the like) is used as a light source for exposure. (Not shown), the substrate 2 on which the lens forming material 40 is formed is placed on an exposure table, and the above-described photomask 35 is positioned on the lens forming material 40 and is placed opposite to it. In the second lens formation step, the lens forming material 40 on the substrate 2 is exposed through the photomask 35 with the exposure light L1 emitted from the light source by an exposure apparatus under appropriately selected exposure conditions. Thus, in the second lens forming step, the portion of the lens forming material 40 on the substrate 2 corresponding to the transmitting portions 37A of the plurality of lens unit mask patterns 37 of the photomask 35 is exposed and photocured. Incidentally, in the second lens forming step, for example, the photomask 35 is placed in a defocused state (that is, not focused on the surface of the lens forming material 40) by, for example, the exposure apparatus. Through one or more exposures, it can be photocured to substantially the shape of the microlens 25. In the second lens forming step, if necessary, the lens forming material 40 after exposure is baked to accelerate the curing reaction of the photocured portion of the lens forming material 40. Can be insolubilized in the developer.

  Subsequently, as shown in FIG. 8C, in the lens forming procedure, the lens forming material 40 on the substrate 2 is developed using an alkaline aqueous solution or a predetermined solvent in the third lens forming step. Then, the unexposed portions of the lens forming material 40 are removed so as to elute, and the microlenses 25 are respectively formed on the plurality of LEDs 12. In the third lens forming step, after the plurality of microlenses 25 after development are dried by rotating the substrate 2 or the like, a post-baking process is performed on the plurality of microlenses 25 as necessary. The plurality of microlenses 25 are cured. In this way, in the lens forming procedure, the lens forming material 40 on the substrate 2 is exposed at least once using the photomask 35, so that the lens root portions are respectively formed on the plurality of LEDs 12 on the one surface 2A of the substrate 2. The microlens 25 having a circular shape 25A and a substantially hemispherical lens tip 25B can be formed.

(1-3) Operation and Effect of First Embodiment In the above configuration, in the display module 1, a plurality of lens unit pattern forming regions are used for exposure of the lens forming material 40 in the lens forming procedure of the LED micro display 3. A photomask 35 on which a lens unit mask pattern 37 is formed is used. However, in the lens formation procedure, a lens for exposing a lens forming material to form a lens apex portion of the microlens 25 as a lens unit mask pattern 37 at the center in a plurality of lens unit pattern formation regions of the photomask 35. In addition to providing the vertex forming transmission part 37AX, an annular lens outer shape forming transmission part 37AY having a predetermined width for exposure for forming the lens outer shape part is provided as the lens unit mask pattern 37 along the region edge, As a lens unit mask pattern 37 between the lens apex forming transmissive part 37AX and the lens outer shape forming transmissive part 37AY, a plurality of transmissive parts 37A and a plurality of transmissive parts 37A for exposing the lens forming material for forming the peripheral part of the lens apex are provided. The light shielding portion 37B is provided in a predetermined pattern. In the lens forming procedure, the lens forming material 40 is formed on the one surface 2A of the substrate 2 in the first lens forming step, and then in the second lens forming step, the exposure device defocuses with the exposure light L1 emitted by the light source. Then, the lens forming material 40 on the substrate 2 is exposed one or more times through the photomask 35, and then the lens forming material 40 on the substrate 2 is developed in the third lens forming step to develop the substrate 2 A cylindrical microlens 25 was formed on each of the plurality of LEDs 12 on one surface 2A.

  Therefore, in the lens forming procedure, when the lens forming material 40 on the substrate 2 is exposed, the exposure light L1 transmitted through the lens apex forming transmitting portion 37AX of the lens unit mask pattern 37 of the photomask 35 is used in the lens forming material 40. The lens apex portion of the microlens 25 can be photocured in a self-supporting state. Further, in the lens formation procedure, the lens outer shape portion of the microlens 25 can be photocured over the entire circumference of the lens forming material 40 by the exposure light L1 transmitted through the lens outer shape forming transmission portion 37AY of the lens unit mask pattern 37. Therefore, in the lens forming procedure, the exposure light L1 transmitted through the plurality of transmitting portions 37A of the lens unit mask pattern 37 is used to photocure a plurality of locations as the lens apex peripheral portion of the microlens 25 in the lens forming material 40. With the lens outer shape portion thus made, it is possible to prevent the plurality of photocuring portions in the peripheral portion of the lens apex from falling down away from the lens apex portion and to be inclined so as to approach the lens apex portion. Further, in the lens forming procedure, even if there is an underexposed portion that is not sufficiently photocured inside the lens outer shape portion of the microlens 25 in the lens forming material 40, the light during the development of the lens forming material 40 It is possible to prevent the underexposed portion from being excessively eluted by the cured lens outer shape portion. As a result, in the lens formation procedure, it is possible to prevent the lens root portion 25A of the microlens 25 from becoming significantly thinner than the original thickness. Further, in the lens formation procedure, the substrate 2 is rotated during drying after development with respect to a plurality of unexposed portions around the lens apex in the lens forming material 40 by the plurality of light shielding portions 37B of the lens unit mask pattern 37. Even if a centrifugal force is applied at this time, the plurality of non-exposed portions can be prevented from being peeled off from the microlens 25 by the lens outer shape portion that has been photocured. According to the above configuration, in the lens formation procedure of the LED micro display 3, each columnar shape is formed on the plurality of LEDs 12 on the one surface 2A of the substrate 2 by the first to third lens forming steps by one photolithography. The microlens 25 can be formed. Thereby, in the lens formation procedure of the LED micro display 3, the lens formation process can be remarkably reduced and the micro lens 25 can be easily formed.

  By the way, in the conventional lens forming procedure, the negative resist transferred onto the substrate in the seventh lens forming step is heat-treated, so that the upper portion of the second lens support in the negative resist is formed into a substantially hemispherical lens of a microlens. The tip is deformed into a curved surface. However, in the conventional lens forming procedure, it is difficult to manage the heat treatment temperature and heat treatment time for the negative resist for deforming the upper portion of the second lens column into a desired curved surface in the negative resist, and the negative resist is desired. In some cases, the microlens cannot be accurately formed without the curved shape. In contrast, in the lens forming procedure according to the first embodiment, the lens forming material 40 is not subjected to any heat treatment that causes deformation before exposure, and the lens forming material 40 is passed through the photomask 35. Since the microlens 25 is shaped so as to be exposed, the microlens 25 can be formed with high accuracy.

(2) Second Embodiment (2-1) Configuration of Display Module Next, the configuration of the display module 45 according to the second embodiment will be described with reference to FIG. Will be described. The display module 45 is configured in the same manner as the display module 1 according to the first embodiment described above, except for a partial configuration of the LED micro display 46. In the display module 45 according to the second embodiment, the partial configuration of the LED micro display 46 is different from the configuration of the LED micro display 3 according to the first embodiment, but the equivalent circuit is described above with reference to FIG. Since it is the same as that, description is abbreviate | omitted. Therefore, in the following, in FIG. 10 in which the same reference numerals are assigned to the corresponding parts to FIG. 3 and FIG. 11 in which the same reference numerals are assigned to the corresponding parts to FIG. The difference in configuration from the LED micro display 3 according to the embodiment will be described. Incidentally, in the LED micro display 46 according to the second embodiment, a plurality of LEDs 12 are arranged on the substrate 2 as in the case of the first embodiment described above. FIG. 10 shows the LED micro display. In FIG. 46, a portion where 4 × 4 LEDs 12 are arranged in a matrix is partially shown. Further, FIG. 11 shows a section where one LED 12 is arranged in the LED micro display 46 as a cross section taken along the B1-B2 cutting line shown in FIG.

  As shown in FIGS. 10 and 11, the LED micro display 46 has a plurality of strip-like anode lines 47 which are long in the column direction (vertical direction) on the smoothing layer 24 provided on the one surface 2 </ b> A of the substrate 2. It is formed insulated from the cathode line 11 through the film 26. In the LED micro display 46, a P contact electrode 47A projecting from the anode line 47 is formed at the center of the light emitting region of the LED 12, and the first light emitting region 29AX and the second light emitting region 29AX are substantially equal in shape and size. The ohmic contact is made so as to divide the light emitting region 29AY. The LED micro display 46 is formed by positioning a cylindrical microlens 48 for converging light on each of the plurality of LEDs 12. Here, each of the plurality of microlenses 48 is formed as a curved surface in which the lens base portion 48A is circular and the front end surface of the lens front end portion 48B protrudes from two points that are equidistant from the center position. That is, in each of the plurality of microlenses 48, the first lens portion 48BX in which the position of one apex of the lens tip 48B is located on the optical axis and the second lens portion 48BY in which the position of the other apex is located on the optical axis are integrated. Is provided. The plurality of microlenses 48 are arranged on the corresponding LEDs 12 so that the optical axis of the first lens portion 48BX is in the center of the first light emitting region 29AX and coincides with the first virtual straight line that is vertical, and the light of the second lens portion 48BY. The axis is arranged so as to coincide with the second imaginary straight line perpendicular to the center of the second light emitting region 29AY. The display module 45 respond | corresponds to the light radiated | emitted from 1st light emission area | region 29AX of several LED12 by operating the drive circuit 4 similarly to the case of 1st Embodiment based on the structure which concerns, respectively. The first lens portion 48BX of the microlens 48 is converged and emitted to the outside, and the light emitted from the second light emitting areas 29AY of the plurality of LEDs 12 is converged by the corresponding second lens portion 48BY of the microlens 48. And can be emitted to the outside.

(2-2) Manufacturing Procedure of LED Micro Display Next, a manufacturing procedure of the LED micro display 46 will be described. The manufacturing procedure of the LED micro display 46 can be roughly divided into an LED formation procedure and a lens formation procedure, as in the case of the first embodiment described above. In the LED formation procedure, a plurality of LEDs 12 are formed together with the anode line 47 and the cathode line 11 on the one surface 2A of the substrate 2 basically in the same manner as in the first embodiment. In the lens formation procedure, the photomask used for exposure of the lens forming material 40 is different from the photomask 35 according to the first embodiment described above, and the processing procedure itself is the same as that in the first embodiment described above. It is the same as the case of. Therefore, hereinafter, a photomask used for exposure of the lens forming material 40 in the lens forming procedure will be described. Similar to the photomask 35 according to the first embodiment described above with reference to FIG. 5, such a photomask has a plurality of lens unit mask patterns having the same configuration on one surface of the light transmission substrate 36, and a plurality of micromasks on the substrate 2. A light shielding film 38 is formed in addition to the positions where the plurality of lens unit mask patterns are formed, corresponding to the arrangement positions of the lenses 48.

  However, as shown in FIG. 12, the photomask 49 has the lens forming material 40 as the lens unit mask pattern 50 in one of two locations equidistant from the center position of the lens unit pattern formation region. A circular first lens apex forming transmission portion 50AX for exposure for forming a vertex portion of one lens portion 48BX and a corresponding portion of the lens base portion 48A (hereinafter collectively referred to as a first lens apex portion) is provided. Is provided. In addition, the photomask 49 has the lens unit material 40 as the lens unit mask pattern 50 at the other of the two positions equidistant from the center position of the lens unit pattern formation region, and the apex portion of the second lens portion 48BY of the microlens 48. And a circular second lens apex forming transmission portion 50AY for exposure for forming a corresponding portion of the lens root portion 48A (hereinafter collectively referred to as a second lens apex portion). Furthermore, the photomask 49 has a predetermined width for exposing the lens forming material 40 for forming the lens outer shape portion of the microlens 48 as the lens unit mask pattern 50 along the region edge of the lens unit pattern forming region. An annular lens outer shape forming transmission portion 50AZ is provided. Furthermore, the photomask 49 is formed as a lens unit mask pattern 50 between the first lens apex forming transmission part 50AX, the second lens apex formation transmission part 50AY, and the lens outer shape formation transmission part 50AZ in the lens unit pattern formation region. For example, a plurality of rectangular transmissions for exposing the lens forming material 40 to form a lens apex peripheral portion between the first lens apex portion, the second lens apex portion, and the lens outer shape portion of the microlens 48. The part 50A and a plurality of light shielding parts 50B having various shapes such as a rectangular shape or a substantially triangular shape are provided in a predetermined pattern such as a checkered pattern.

  The lens unit mask pattern 50 includes a size of a plurality of transmission parts 50A including a first lens vertex formation transmission part 50AX, a second lens vertex formation transmission part 50AY, and a lens outer shape formation transmission part 50AZ, and a plurality of light shielding parts 50B. Is appropriately selected as in the case of the photomask 35 according to the first embodiment described above. In this way, the photomask 49 is formed so that the plurality of lens unit mask patterns 50 can expose the lens forming material 40 for forming the microlenses 48. Therefore, in the lens forming procedure, after the lens forming material 40 is formed on the surface 2A of the substrate 2 in the first lens forming step, the photomask 49 is formed by the exposure light L1 emitted from the light source by the exposure device in the second lens forming step. Then, the lens forming material 40 on the substrate 2 is exposed to light, and then the lens forming material 40 on the substrate 2 is developed in the third lens forming step, so that as shown in FIG. A microlens 48 having a lens root portion 48A and a lens tip portion 48B having a first lens portion 48BX and a second lens portion 48BY can be formed on the plurality of LEDs 12, respectively.

(2-3) Operation and Effect of Second Embodiment In the above configuration, in the display module 45, a plurality of lenses of the photomask 49 used for exposure of the lens forming material 40 in the lens forming procedure of the LED micro display 46 A lens unit mask pattern 50 having a first lens apex forming transmission portion 50AX and a second lens apex formation transmission portion 50AY was formed in each unit pattern formation region. In the lens forming procedure, the lens forming material 40 is formed on the one surface 2A of the substrate 2 in the first lens forming step, and then in the second lens forming step, the exposure device defocuses with the exposure light L1 emitted by the light source. Then, the lens forming material 40 on the substrate 2 is exposed one or more times through the photomask 49, and then the lens forming material 40 on the substrate 2 is developed in the third lens forming step to develop the substrate 2 A cylindrical microlens 48 was formed on each of the plurality of LEDs 12 on one surface 2A. According to the above configuration, in the lens formation procedure of the LED micro display 46, the first lens formation process to the third lens formation process by one photolithography are respectively performed on the plurality of LEDs 12 on the one surface 2A of the substrate 2. A cylindrical microlens 48 having a lens portion 48BX and a second lens portion 48BY can be formed. Thereby, also in the lens formation procedure of the LED micro display 46, the effect similar to the effect acquired by 1st Embodiment mentioned above can be acquired.

(3) Other embodiments (3-1) Other embodiments 1
In the first embodiment described above, an annular lens outer shape forming transmission portion is provided along the edge of the lens unit mask pattern 37 in the photomask 35 (that is, along the region edge of the lens unit pattern formation region). The case where 37AY is provided has been described. However, the present invention is not limited to this. For example, as shown in FIG. 14, a plurality of arc-shaped lens outer shape forming transmission portions 56 </ b> AY are sequentially provided along the edge of the lens unit mask pattern 56 in the photomask 55. Anyway. In the present invention, the gap between adjacent lens outline forming transmission portions 56AY is selected as a predetermined gap that is equal to or greater than the resolution limit of the exposure apparatus, and the length of the plurality of lens outline formation transmission portions 56AY is set to the light shielding portion. A predetermined equal length longer than one size of 56B (that is, the shortest one of the sides of the light shielding portion 56B) is selected. The present invention also corresponds to the plurality of lens outer shape forming transmission portions 56AY of the lens unit mask pattern 56 in the lens forming material 40 when the lens forming material 40 is exposed through the photomask 55 even with such a configuration. The part can be photocured as a lens outer shape part while being inclined so as to be attracted to the lens apex part. Therefore, according to the present invention, a cylindrical microlens can be formed on each of the plurality of EDs 12 even with such a configuration, and the same effect as that obtained by the first embodiment can be obtained. Further, according to the present invention, in the case of such a configuration, a plurality of arc-shaped lens outer shape forming transmission portions 56AY having the same length are provided along the edge portion of the lens unit mask pattern 56, thereby forming a lens through the photomask 55. When the material 40 is exposed, the portions corresponding to the plurality of lens outer shape forming transmission portions 56AY can be inclined at substantially the same inclination angle so as to be attracted to the lens apex portion. As a result, according to the present invention, there is a partial variation in the inclination to the lens apex portion over the circumference of the lens outer shape portion, and distortion occurs in the boundary portion between the lens root portion and the lens tip portion in the microlens. Can be prevented.

(3-2) Other Embodiment 2
In the first embodiment described above, a plurality of quadrangular transmission parts 37A are provided between the lens vertex formation transmission part 37AX and the lens outer shape formation transmission part 37AY in the lens unit mask pattern 37 of the photomask 35. A case has been described in which a plurality of light-shielding portions 37B having various shapes such as a quadrangular shape or a substantially triangular shape are provided in a predetermined pattern such as a checkered pattern. However, the present invention is not limited to this. For example, as shown in FIG. 15, a lens is formed between the lens apex forming transmission part 61AX and the lens outer shape forming transmission part 61AY in the lens unit mask pattern 61 of the photomask 60. For example, for exposing the material 40 for forming the peripheral portion of the lens apex of the microlens 25, one or a plurality of annular shapes each having a different diameter and appropriately selected in the radial direction of the lens unit mask pattern 61 The transmissive portions 61AZ and the one or more light shielding portions 61B may be alternately provided in a concentric fashion. According to the present invention, when the lens forming material 40 is exposed through the photomask 60 on which the lens unit mask pattern 61 is formed, the annular shape corresponding to the transmission portion 61AZ in the lens forming material 40 is obtained. The portion can be tilted so as to be attracted to the lens apex portion, and can be photocured so as to form a curved surface of the lens front end portion 25B as a portion around the lens apex. Further, in the present invention, since the portions corresponding to the light shielding portion 61B in the lens forming material 40 are connected in a ring shape, the lens forming material 40 is prevented from being separated in the direction away from the top portion of the lens by being separated by exposure or development after exposure. Can do. Therefore, in the present invention, even if the lens forming material 40 is exposed through the photomask 60 in which the lens unit mask pattern 61 having the above structure is formed, the columnar shape is the same as in the case of the first embodiment described above. The microlens 25 can be formed. Further, according to the present invention, in the case of such a configuration, in the lens unit mask pattern 61 of the photomask 60, one or a plurality of transmission portions 61AZ and one or a plurality of light shielding portions 61B are provided in a concentric manner as an annular shape. Design can be simplified. By the way, in the present invention, one or a plurality of transmission portions 61AZ and one or a plurality of light shielding portions 61B provided in the lens unit mask pattern 61 of the photomask 60 may be polygonal without being annular. In addition, the present invention avoids the adjustment of the ratio of one or a plurality of transmission portions 61AZ and the one or a plurality of light-shielding portions 61B provided in the lens unit mask pattern 61 of the photomask 60 or distortion of the microlens 25. Therefore, an arc shape or a bow shape that is appropriately divided along the circumferential direction may be used. In the present invention, these various configurations are combined with a configuration in which a plurality of arc-shaped lens outer shape forming transmission portions 56AY are sequentially provided along the edge of the lens unit pattern formation region described above for the first embodiment. You can also.

(3-3) Other Embodiment 3
Further, in the first and second embodiments described above, the lens apex forming transmission portion 37AX is provided at the central portion of the lens unit mask patterns 37, 50 of the photomasks 35, 49, or at two locations equidistant from the central position. In addition, the case where the first lens apex forming transmitting portion 50AX and the second lens apex forming transmitting portion 50AY are provided has been described. However, the present invention is not limited to this. For example, as shown in FIG. 16, a circular lens apex is formed at a predetermined position between the center position and the lens outer shape forming transmission portion 66AX in the lens unit mask pattern 66 of the photomask 65. The forming transmission part 66AY may be provided. In the lens unit mask pattern 66, when the lens forming material 40 is exposed to the size (that is, the diameter) of the lens apex forming transmitting portion 66AY through the photomask 65, the lens forming material 40 is provided. A predetermined size that can be photocured in a self-supporting state without tilting the portion corresponding to the lens apex forming transmission portion 66AY as a lens apex portion (that is, a predetermined size that is greater than or equal to the resolution limit by the exposure apparatus) Select According to the present invention, as shown in FIG. 17, the lens forming material 40 is exposed to light through a photomask 65 and then developed to develop a cylindrical shape on the LED 12 on the first surface 2 </ b> A of the substrate 2. The microlens 67 can be formed as a decentered lens having a curved surface that protrudes with the position where the tip surface of the lens tip portion 67A deviates from the center position as a vertex. In the present invention, for example, as shown in FIG. 18, in the lens unit mask pattern 71 of the photomask 70, a lens apex forming transmission part 71AX is provided at the center, and the lens apex forming transmission part 71AX and the lens outer shape formation are provided. An annular lens apex forming transmission part 71AZ may be provided between the transmission part 71AY for use. In the present invention, the size of the lens apex forming transmission portion 71AZ in the lens unit mask pattern 71 (that is, the width along the radial direction of the lens unit mask pattern 71) is determined by the lens forming material 40 via the photomask 70. When exposed, the lens forming material 40 has a predetermined size that can be photocured in a self-supporting state without tilting the portion corresponding to the lens apex forming transmitting portion 71AZ as an annular lens apex portion (that is, Select a predetermined size that is equal to or greater than the resolution limit of the exposure apparatus). According to the present invention, as shown in FIG. 19, the lens forming material 40 is exposed through a photomask 70 and then developed, so that the front end of the lens is formed on the LED 12 on the first surface 2A of the substrate 2. A cylindrical microlens 72 having a curved surface such as a ripple that projects the tip surface of the portion 72A with the center position as a vertex and the position of a circle centering on the vertex as a top is formed. be able to. Incidentally, the present invention combines these various configurations with a configuration in which a plurality of arc-shaped lens outer shape forming transmission portions 56AY are sequentially provided along the edge of the lens unit pattern formation region described in the other embodiment 1. You can also.

(3-4) Other Embodiment 4
Further, in the first and second embodiments described above, the case where the microlenses 25 and 48 are respectively formed on the plurality of LEDs 12 on the one surface 2A of the substrate 2 has been described. However, the present invention is not limited to this, and a light shielding portion may be provided between the plurality of microlenses 25 and 48 on the surface 2A of the substrate 2. For example, as shown in FIG. 20A, in the lens forming procedure, a lens forming material made of a negative transparent photosensitive resist material on the plurality of LEDs 12 on one surface 2A of the substrate 2 by a photolithography technique. Then, the lens support 75 is formed. Next, as shown in FIG. 20B, in the lens formation procedure, a black resist in which the gap between the plurality of lens columns 75 is filled with a spin coating method, a screen printing method, or a dispenser on one surface 2A of the substrate 2 by a photolithography technique. Alternatively, the light shielding portion 76 is formed in the gap between the plurality of lens columns 75 based on the white resist. For example, the black resist can be generated by dispersing a predetermined black colorant such as carbon black or titanium black in a predetermined resin material such as an acrylic resin or an epoxy resin. In addition, the white resist is prepared by dispersing a predetermined white colorant such as rutile titanium oxide, zirconium oxide, magnesium oxide, asbestos, or zinc oxide in a predetermined resin material such as an epoxy resin, an acrylic resin, or an olefin resin. Can be generated. Subsequently, as shown in FIG. 20C, in the lens forming procedure, the lens forming material 40 is coated on the one surface 2A of the substrate 2 so as to cover the plurality of lens columns 75 and the light shielding portion 76 by a photolithography technique. Then, the lens forming material 40 on the substrate 2 is exposed through, for example, the photomask 35 described above with reference to FIGS. 5 and 6 by the exposure apparatus, developed, and subjected to heat treatment as necessary. As a result, as shown in FIG. 20D, in the lens forming procedure, a cylindrical microlens 77 integrated with the lens support 75 is formed on the plurality of LEDs 12 on one surface 2A of the substrate 2, and a plurality of microlenses are formed. A light blocking portion 76 can be interposed in the gap between the lenses 77.

  According to the present invention, when the light shielding part 76 is formed of a black resist, the light shielding part 76 can absorb the light emitted from the LED 12 and radiated in the side surface direction of the microlens 77. . As a result, the present invention can suppress the light radiated in the side surface direction of the microlens 77 from becoming stray light with respect to the adjacent LEDs 12 and the like. Further, according to the present invention, when the light shielding portion 76 is formed of a white resist, the light emitted from the LED 12 and emitted in the direction of the side surface of the microlens 77 is transmitted to the inside of the microlens 77 (that is, the microlens 77). Can be reflected on the inside of the lens column 75, which is a part of the lens column 75. As a result, in this case as well, the light emitted in the direction of the side surface of the microlens 77 can be suppressed from becoming stray light with respect to the adjacent LEDs 12 and the like. Light reflected inside the microlens 77 can be emitted from the lens tip of the microlens 77 to the outside. Furthermore, according to the present invention, the microlens 77 having a relatively high aspect ratio can be obtained by forming the lens column 75 on the plurality of LEDs 12 and then forming the microlens 77 integrated with the lens column 75. .

(3-5) Other Embodiment 5
Furthermore, in the first and second embodiments described above, the lens unit mask patterns 37 and 50 of the photomasks 35 and 49 include a circular lens apex forming transmission part 37AX, a first lens apex formation transmission part 50AX, and The case where the second lens apex forming transmitting portion 50AY is provided has been described. However, the present invention is not limited to this, and the lens unit mask patterns 37 and 50 of the photomasks 35 and 49 include a polygonal lens apex forming transmission part 37AX, a first lens apex forming transmission part 50AX, and a second lens apex. The forming transmission part 50AY may be provided. The present invention can obtain the same effects as those obtained by the first and second embodiments described above even with such a configuration. Note that the present invention can be combined with any of the above-described configurations in the first to fourth embodiments.

(3-6) Other Embodiment 6
Furthermore, in the first and second embodiments described above, the lens forming method, photomask and light emitting device according to the present invention are applied to the LED microdisplays 3 and 46 of the display modules 1 and 45 described above with reference to FIGS. Lens forming method for forming microlenses 25 and 48 on the plurality of LEDs 12, photomasks 35 and 49 used for forming the microlenses 25 and 48, and microlenses 25 and 48 formed on the plurality of LEDs 12 and the LEDs 12. The case where the present invention is applied to the LED microdisplays 3 and 46 having the above is described. However, the present invention is not limited to this, and a lens forming method for forming microlenses on a plurality of LEDs in an exposure unit provided in an image forming apparatus such as an electrophotographic printer, an MFP (Multi-Function Peripheral), and a facsimile, A photomask used for forming a microlens, a lens forming method for forming a microlens on a light emitting element such as an organic EL (Electro Luminescence) element or an inorganic EL element formed on one surface of the photomask and its exposed portion, and the microlens Various other types such as a photomask used for forming a lens and a light emitting device having one or a plurality of light emitting elements such as an organic EL element or an inorganic EL element and a microlens formed on the light emitting element. The present invention can be widely applied to a lens forming method, a photomask, and a light emitting device.

(3-7) Other Embodiment 7
Further, in the first and second embodiments described above, the case where the LED 12 having the rectangular light emitting region described above with reference to FIGS. 1 and 9 is applied as the light emitting element mounted on one surface of the substrate will be described. It was. However, the present invention is not limited to this, and other light-emitting elements having various configurations such as an organic EL element, an inorganic EL element, an elliptical shape, a pentagonal or more polygonal shape, and a light-emitting element having a circular light-emitting region can be used. Can be widely applied.

(3-8) Other Embodiment 8
Further, in the first and second embodiments described above, the columnar microlenses 25 and 48 described above with reference to FIGS. 1 and 9 are used as the columnar lenses formed on the light emitting elements mounted on one surface of the substrate. , 67, 72, 77 have been described. However, the present invention is not limited to this, and a wide variety of lenses having various configurations, such as a polygonal columnar macro lens with rounded corners and an elliptic columnar microlens, can be applied.

  The present invention relates to a lens forming method for forming a microlens on a light emitting element such as an LED, an organic EL element, or an inorganic EL element, a photomask used for forming the microlens, and an LED, an organic EL element, an inorganic EL element, or the like. It can be used for a light emitting device having a light emitting element and a microlens formed on the light emitting element.

  1, 45 ... Display module, 2 ... Substrate, 2A ... One side, 3, 46 ... LED micro display, 12 ... LED, 25, 48, 67, 72, 77 ... Micro lens, 35, 49, 55, 60, 65, 70 ... Photomask, 37, 50, 56, 61, 66, 71 ... Lens unit mask pattern, 37A, 50A, 61AZ ... Transmission part, 37AX, 61AX, 66AY, 71AX, 71AZ ... ... lens apex forming transmission part, 37AY, 50AZ, 56AY, 61AY, 66AX, 71AY ... lens outer shape forming transmission part, 37B, 50B, 56B, 61B, 76 ... light shielding part, 40 ... lens forming material, 50AX: first lens apex forming transmission part, 50AY: second lens apex forming transmission part, 75: lens support.

Claims (10)

A lens forming method for forming a columnar lens on a light emitting element mounted on one surface of a substrate,
A material forming step of forming a negative lens forming material on the one surface of the substrate so as to cover the light emitting element;
An exposure process in which an exposure apparatus is used to expose the lens forming material on the one surface of the substrate through a photomask in which a lens forming mask pattern is formed in a pattern forming region having a shape corresponding to the lens outer shape. When,
Developing the lens forming material exposed on the one surface of the substrate to form the lens on the light emitting element, and
In the exposure step,
For the exposure of the lens forming material, a lens vertex forming transmission portion provided at a predetermined position with respect to the pattern formation region, a transmission portion and a light shielding portion provided around the lens vertex formation transmission portion, and a region A lens forming method using the photomask on which the mask pattern having a lens outer shape forming transmission portion having a predetermined width provided along an edge portion is formed. In the exposure step,
For the exposure of the lens forming material, the size of the lens apex forming transmissive part, the transmissive part and the lens outer shape forming transmissive part is selected to be larger than the resolution limit of the exposure apparatus, 2. The photomask in which the mask pattern selected so that the size of the light-shielding portion is not less than the resolution limit of the exposure apparatus and not more than the resolution limit of the lens forming material is used. The lens formation method as described in. In the exposure step,
For the exposure of the lens forming material, the photomask in which the mask pattern having the lens outer shape forming transmission portion provided over the entire periphery of the pattern forming region along the region edge is used. The lens forming method according to claim 1 or 2. In the exposure step,
For exposure of the lens forming material, the photomask in which the mask pattern having a plurality of lens outer shape forming transmission portions provided in order along the region edge with respect to the pattern forming region is used. ,
The photomask is
The lengths of the plurality of lens outline forming transmission portions are selected to be at least one size of the light shielding portion, and a gap between adjacent lens outline formation transmission portions is a resolution limit of the exposure apparatus. The lens forming method according to claim 1 or 2, wherein the gap is selected as described above. In the exposure step,
The photomask in which the mask pattern having the lens apex-forming transmissive portion provided at the center position of the pattern formation region is used for exposure of the lens forming material. 5. The lens forming method according to any one of 4 above. In the exposure step,
The photomask in which the mask pattern having the lens apex-forming transmission portion provided at a position shifted from the center position of the region with respect to the pattern formation region is used for exposure of the lens forming material. The lens forming method according to claim 1. In the exposure step,
For the exposure of the lens forming material, the mask pattern having the ring-shaped or polygonal transmissive portions and the light-shielding portions, which are alternately provided around the transmissive portion for forming the lens apex with respect to the pattern formation region, is formed. The lens forming method according to claim 1, wherein the photomask is used. A column forming step of forming a lens column on the light emitting element on the one surface of the substrate;
A light shielding part forming step of forming a light shielding part adjacent to the lens column on the one surface of the substrate;
In the material forming step,
Forming the lens forming material on the one surface of the substrate so as to cover the light emitting element, the lens column, and the light shielding portion;
In the exposure step,
Using the exposure apparatus, the lens forming material on the one surface of the substrate is exposed through the photomask,
In the development step,
The lens forming method according to claim 1, wherein the lens forming material exposed on the one surface of the substrate is developed to form the lens on the lens column. A photomask used for exposure when a columnar lens is formed on a light emitting element mounted on one surface of a substrate,
With respect to the pattern formation region having a shape corresponding to the lens outer shape, the lens vertex forming transmission portion provided at a predetermined position, the transmission portion and the light shielding portion provided around the lens vertex formation transmission portion, and the region edge A photomask on which the mask pattern having a lens outer shape forming transmission portion having a predetermined width is provided. A light emitting device mounted on one side of the substrate;
A lens apex forming transmissive portion provided at a predetermined position with respect to a pattern forming region having a shape corresponding to the lens outer shape, with a negative lens forming material formed on the one surface of the substrate so as to cover the light emitting element. And a photomask formed with a mask pattern having a transmissive portion and a light shielding portion provided around the transmissive portion for forming the lens apex, and a transmissive portion for forming a lens outer shape having a predetermined width provided along the region edge. A light-emitting device comprising: a columnar lens formed on the light-emitting element after being exposed through a mask and developed.

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