JP2012238411A - Method for manufacturing led illumination substrate - Google Patents

Abstract

An object of the present invention is to provide a method for manufacturing an LED lighting substrate capable of ensuring good illumination characteristics at low cost.
In manufacture of an LED lighting board configured by mounting a plurality of LED elements on a substrate, a mounting reference position for mounting a light diffusing lens for a substrate on which the plurality of LED elements are mounted at the element mounting position When the lens is mounted after the adhesive is transferred to the light diffusing lens, the light diffusing lens is mounted on each LED element based on the detected mounting reference position. Thereby, a light diffusing lens can be mounted at an appropriate position with respect to the LED element, and good illumination characteristics can be ensured at low cost in the manufacture of the LED illumination board.
[Selection] Figure 2

Description

  The present invention relates to a method for manufacturing an LED lighting board configured by mounting a plurality of LED elements on a board.

  As a light source device for a backlight of a display panel such as a liquid crystal panel, an LED illumination board having LED elements mounted on the board is widely used. The backlight of a display panel is required to provide uniform illuminance at each position in the panel region, and a large number of LED elements are generally arranged at high density on the LED illumination substrate used for this purpose. For this reason, it is inevitable that the LED illumination substrate for backlight is expensive, and the cost reduction of the LED illumination substrate has been demanded conventionally. In order to respond to such a request, a method of attaching a light diffusion lens to the LED element is used for the purpose of reducing the cost by reducing the number of LED elements (for example, Patent Document 1). reference). The prior art disclosed in Patent Document 1 shows an example of a light diffusing lens for uniformly diffusing LED divergent light in the center direction, the periphery, and the side direction of the lens.

JP 2006-332054 A

  However, in the prior art including the above-described prior art examples, there is a problem that the illuminance of the illumination light becomes non-uniform due to the difficulty in correctly aligning the light diffusion lens with respect to the LED element. It was. That is, in the prior art, in the mounting process of mounting the light diffusing lens on the substrate on which the plurality of LED elements are mounted, alignment is performed using mounting position data prepared in advance at the design stage. However, the position of the LED element after mounting is not necessarily the same as the mounting position data, and some errors are unavoidable. Furthermore, the light emission characteristics of the individual LED elements are not uniform, and the luminance center of the illumination light does not always coincide with the center position of the LED elements. For this reason, when the light diffusing lens is mounted on the LED element using the mounting position data, the distribution characteristics of the illumination light as the backlight will vary. As described above, the conventional technique has a problem that it is difficult to ensure good illumination characteristics of the LED illumination board at low cost.

  Then, this invention aims at providing the manufacturing method of the LED lighting board which can ensure a favorable illumination characteristic at low cost.

  The manufacturing method of the LED lighting board of the present invention is a manufacturing method of an LED lighting board that manufactures an LED lighting board in which a plurality of LED elements mounted on a board are used as light sources and a light diffusion lens is individually attached to the LED elements. A mounting reference position detecting step for detecting a mounting reference position for mounting the light diffusing lens for a substrate on which the plurality of LED elements are mounted at an element mounting position; and The light diffusion lens is attached to each LED element based on the adhesive transfer step of transferring the adhesive for fixing to the mounting position to the light diffusion lens and the attachment reference position detected in the attachment reference position detection step. A lens mounting step for contacting the adhesive, and heating the substrate after the lens mounting step to cure the adhesive and fix the light diffusion lens to the substrate. And a hardening step.

  According to the present invention, a mounting reference position for mounting a light diffusing lens is detected on a substrate on which a plurality of LED elements are mounted at the element mounting position, and the lens is mounted after the adhesive is transferred to the light diffusing lens. At this time, the light diffusing lens is mounted on each LED element based on the detected mounting reference position, so that the light diffusing lens can be mounted at an appropriate position with respect to the LED element. Good lighting characteristics can be ensured at a low cost.

The block diagram which shows the structure of the manufacturing system of the LED illumination board of one embodiment of this invention The flowchart which shows each process of the manufacturing method of the LED lighting board of one embodiment of this invention Process explanatory drawing of the manufacturing method of the LED lighting board of one embodiment of this invention Process explanatory drawing of the manufacturing method of the LED lighting board of one embodiment of this invention Process explanatory drawing of the manufacturing method of the LED lighting board of one embodiment of this invention Process explanatory drawing of the manufacturing method of the LED lighting board of one embodiment of this invention Process explanatory drawing of the manufacturing method of the LED lighting board of one embodiment of this invention Process explanatory drawing of the manufacturing method of the LED lighting board of one embodiment of this invention

  Next, embodiments of the present invention will be described with reference to the drawings. First, the configuration of the LED illumination board manufacturing system 1 will be described with reference to FIG. The LED illumination board manufacturing system 1 has a function of manufacturing an LED illumination board in which a plurality of LED elements mounted on a board are used as a light source and a light diffusion lens is individually attached to the LED elements. The LED illumination board manufacturing system 1 includes an LED mounting line 1a in which a plurality of devices for performing an operation of mounting an LED element 12 (see FIG. 4) on a board 4 (see FIG. 3) is connected, and the LED element is mounted. It is roughly divided into a lens mounting line 1b in which a plurality of devices for executing the operation of mounting the light diffusing lens 26 (see FIG. 7) on the substrate after being connected.

  The devices constituting the LED mounting line 1 a and the lens mounting line 1 b are connected to each other via the LAN system 2 and further connected to the management computer 3. The LED mounting line 1a and the lens mounting line 1b may be arranged as a series of manufacturing lines. The LED mounting line 1a and the lens mounting line 1b are independent manufacturing lines. The substrate 4 of the intermediate product may be conveyed between them (arrow a).

  Here, each apparatus which comprises LED mounting line 1a is demonstrated. The printing apparatus M1 prints solder for component joining on the substrate 4 serving as a base constituting the illumination substrate. The print inspection apparatus M2 inspects the printing state such as the printing position and the amount of solder printed on the substrate 4. The component mounting apparatus M3 mounts the LED element 12 on the board 4 after solder printing. The mounting inspection device M4 inspects the mounting state such as the position of the LED element 12 on the substrate 4. The reflow device M5 heats the substrate 4 after the LED elements are mounted, melts the solder, and joins the LED elements 12 to the substrate 4.

  Next, each device constituting the lens mounting line 1b will be described. The position detection device M6 detects a mounting reference position for mounting the light diffusion lens 26 by performing a predetermined measurement operation on the substrate 4 on which the LED element 12 is mounted. The lens mounting device M7 includes an adhesive transfer portion that transfers an adhesive for fixing the light diffusing lens 26 to the substrate 4 to the light diffusing lens 26, and the light diffusing lens 26 after the adhesive transfer is mounted on the substrate 4. To do. The curing device M8 heats the adhesive by heating the substrate 4 after the light diffusion lens 26 is mounted.

  Next, the manufacturing process flow of the LED illumination board will be described in accordance with the flow shown in FIG. 2 with reference to FIGS. As shown in FIG. 3A, an electrode 4a for joining the LED element 12 is formed at an element mounting position where the LED element 12 is mounted on the substrate 4 serving as a base constituting the illumination board. Although only one electrode 4a is illustrated in the illustrated example, the LED element 12 is mounted on each of the plurality of electrodes 4a on the substrate 4 that is actually used as the illumination substrate.

  The substrate 4 is first carried into the printing apparatus M1, where screen printing is performed on the substrate 4 (ST1). As a result, as shown in FIG. 3B, the solder paste 5 for component joining is printed on the electrode 4a. Next, the substrate 4 is carried into the printing inspection apparatus M2. Here, as shown in FIG. 3C, the substrate 4 on which the solder paste 5 is printed is imaged by the inspection camera 6, and the image pickup result is inspected by the print inspection processing unit 7, whereby the solder on the substrate 4 is soldered. The quality of the printing state of the paste 5 is inspected (ST2). Then, the substrate 4 determined to be a non-defective product based on the print inspection result is carried into the component mounting apparatus M3, where the LED package 9 held by the mounting head 8 is attached to the substrate 4 as shown in FIG. Land on the printed solder paste 5 (ST3).

  FIG. 4A shows a schematic configuration of the LED package 9. Here, after the single LED element 12 is mounted in advance in the LED mounting portion 11 provided on the individual substrate 10, the LED element 12 is resin-sealed with a light emitting resin 13 to form the LED package 9, The example which mounts the LED element 12 of the state of this LED package 9 on the board | substrate 4 is shown. Of course, the structure which manufactures an illumination board | substrate by mounting the single LED element 12 to the board | substrate 4 by solder joining directly may be sufficient.

  Next, the LED-mounted substrate 4 is carried into the mounting inspection apparatus M4. Here, as shown in FIG. 4B, the substrate 4 on which the LED package 9 is mounted is imaged by the inspection camera 14, and this imaging result is inspected by the mounting inspection processing unit 15, whereby the LED package 9. The mounting condition of the LED package 9 on the substrate 4 such as position and orientation is inspected (ST4). And the board | substrate 4 determined with the non-defective product by the mounting inspection result is carried in to the reflow apparatus M5. And by heating the board | substrate 4 with a predetermined heating profile here, as shown in FIG.4 (c), as shown in FIG.4 (c), the soldering joint 5 * which the solder paste 5 melts and solidifies and solders the LED package 9 to the board | substrate 4 is shown. It is formed (ST5).

  FIG. 5A shows the plane of the substrate 4 on which the LED package 9 is mounted in this way. At this time, the LED package 9 after solder bonding is not necessarily defined by the design information due to the component mounting position accuracy in the component mounting apparatus M3 and the movement due to the surface tension of the LED package 9 during solder bonding in the reflow apparatus M5. It is not necessarily in the normal position, and there is some misalignment in both the X direction and the Y direction. When the light diffusing lens 26 is mounted at the normal position shown in the design information with respect to the LED package 9 in such a misaligned state, the optical axis of the light diffusing lens 26 is correctly positioned with respect to the LED element 12 that is a light emitting source. The light diffusion characteristics are varied without being matched. Therefore, in the present embodiment, prior to mounting the light diffusing lens 26, the position of the LED element 12 on the substrate 4 or the luminance center position of the illumination light by the LED element 12 is mounted to mount the light diffusing lens 26. The reference position is detected in advance.

  That is, the substrate 4 after the LED package 9 is mounted is carried into the position detection device M6. Here, as shown in FIG. 5B, the substrate 4 on which the LED package 9 is mounted is imaged by the position detection camera 16, and the image detection result is subjected to position detection processing by the mounting position detection unit 17. The position of the LED package 9 is detected. In this position detection, as shown in FIG. 5C, the center position of the LED element 12 in the LED package 9 is detected as position coordinates in the X direction and the Y direction.

  The position detection result is output as feedforward data via the LAN system 2 to the mounting control unit of the lens mounting apparatus M7 as a mounting reference position for mounting the light diffusing lens (ST6). That is, the mounting reference position for mounting the light diffusion lens 26 is detected for the substrate 4 on which the plurality of LED elements 12 are mounted at the element mounting positions (mounting reference position detecting step). In the example shown in FIG. 5, the mounting reference position is detected based on the position detection result obtained by optically detecting the position of the LED element 12 in the mounting reference position detecting step.

  Instead of optically detecting the position of the LED element 12 and setting it as the reference position for mounting the position detection camera 16, as shown in FIG. 6, the luminance distribution of the illumination light emitted from the LED element 12 is used as a reference. You may do it. That is, as shown in FIG. 6A, the substrate 4 after the LED package 9 is mounted is carried into the position detection device M6A. Here, the light detection unit 22 including the dark room part 21 is located above the substrate 4, and the measurement space enclosed by the dark room part 21 by lowering the light detection unit 22 with respect to the LED package 9. Is formed.

  In this state, power is supplied to the LED package 9 by the power supply device 20 to cause the LED element 12 to emit light, and the emitted illumination light is received by the light detection unit 22. Then, the luminance distribution detection unit 23 processes the light reception result, so that the luminance center CP in the measurement curve L indicating the luminance distribution of the illumination light emitted from the LED element 12 becomes X as shown in FIG. It is obtained for the direction and the Y direction. Similarly, the data indicating the luminance center CP is output via the LAN system 2 as feedforward data to the mounting control unit of the lens mounting device M7.

  That is, in the example illustrated in FIG. 6, in the mounting reference position detection step, the mounting reference position of the light diffusion lens 26 is detected based on the brightness center detection result obtained by detecting the brightness center CP of the illumination light emitted from the LED element 12. I am doing so. By adopting such a method, the light diffusing lens 26 can be mounted at the correct position even when the luminance distribution of the LED element 12 is uneven in luminance distribution.

  Next, the board | substrate 4 is carried in into the lens mounting apparatus M7, and the adhesive agent 25 for adhering the light-diffusion lens 26 is transcribe | transferred to the light-diffusion lens 26 here by the adhesive agent transfer part with which the lens mounting apparatus M7 was equipped. Adhesive transfer step) (ST7). The light diffusion lens 26 is mounted for the purpose of ensuring a wide illumination range as much as possible with a small number of LED elements 12 by diffusing the illumination light emitted by the LED elements 12 of the LED package 9 in the horizontal direction. is there. Thus, since the light diffusion lens 26 is mounted so as to cover the upper side of the LED package 9, in the example shown in the present embodiment, a recess for avoiding interference with the LED package 9 is provided on the lower surface side of the light diffusion lens 26. In order to supply the adhesive 26a and the adhesive 25 by transfer, a protruding portion 26c protruding downward is provided.

  In transferring the adhesive, as shown in FIG. 7A, the light diffusion lens 26 held by the mounting head 27 is moved up and down with respect to the transfer stage 24 on which the coating film of the adhesive 25 is formed. As a result, as shown in FIG. 7B, the adhesive 25 adheres to the lower surface side of the convex portion 26c of the light diffusion lens 26 by transfer. In addition to the shape of the light diffusing lens 26 other than the concave surface 26a and the convex portion 26c provided on the lower surface, it is possible to avoid interference with the LED package 9 and to be fixed to the substrate 4 by the adhesive 25. Various shapes can be appropriately selected and used.

  Next, the light diffusion lens 26 after the adhesive transfer is mounted on the substrate 4 (ST8). That is, the light diffusing lens 26 held by the mounting head 27 is mounted so as to cover the LED package 9, and the adhesive 25 transferred and applied to the convex portion 26 c of the light diffusing lens 26 is brought into contact with the substrate 4.

  In mounting the light diffusing lens 26, the lens mounting mechanism 28 that moves the mounting head 27 is controlled by the mounting control unit 29, thereby aligning the light diffusing lens 26 with the LED element 12. At this time, the mounting control unit 29 is fed forward with data indicating the mounting reference position of the light diffusion lens 26 from the mounting position detection unit 17 of the position detection device M6 or the luminance distribution detection unit 23 of the position detection device M6A. The lens mounting mechanism 28 aligns the light diffusing lens 26 with respect to the LED element 12 according to the mounting reference position. Accordingly, as shown in FIG. 7D, the optical axis point 26b of the light diffusing lens 26 is aligned with the mounting reference position detected in advance. That is, here, based on the mounting reference position detected in the mounting reference position detection step, the light diffusion lens 26 is mounted on the LED element 12 provided in each LED package 9 and brought into contact with the adhesive 25 (lens mounting step). .

  Thereafter, the adhesive 25 is thermally cured (ST9). That is, as shown in FIG. 8A, the substrate 4 after the lens is mounted is carried into the curing device M8, where it is heated under predetermined heating conditions. As a result, the adhesive 25 is thermally cured, and as shown in FIGS. 8B and 8C, the light diffusion lens 26 mounted so as to cover the LED package 9 mounted on the substrate 4 from above is formed as a convex portion 26c. A resin fixing part 25 * is formed to be fixed to the substrate 4 through the adhesive (adhesive curing step).

  As described above, in the method for manufacturing the LED illumination board shown in the present embodiment, the mounting reference position for mounting the light diffusion lens 26 on the substrate 4 on which the plurality of LED elements 12 are mounted at the element mounting position. Is detected in advance, and when the lens is mounted on the light diffusing lens 26 after the adhesive is transferred, the light diffusing lens 26 is mounted on each LED element 12 based on the detected mounting reference position. Thereby, the light diffusion lens 26 can be attached to the LED element 12 at an appropriate position, and good illumination characteristics can be ensured at low cost in the manufacture of the LED illumination board.

  The manufacturing method of the LED lighting board of the present invention has an effect that good lighting characteristics can be secured at low cost, and a technique for manufacturing an LED lighting board configured by mounting a plurality of LED elements on a board. Useful in the field.

1 LED Lighting Board Manufacturing System 4 Board 4a Electrode 5 Solder Paste 5 * Solder Joint 9 LED Package 12 LED Element 24 Transfer Stage 25 Adhesive 26 Light Diffuse Lens

Claims (3)

A method of manufacturing an LED illumination board for producing an LED illumination board comprising a plurality of LED elements mounted on a substrate as a light source and individually attaching a light diffusion lens to the LED elements,
A mounting reference position detecting step for detecting a mounting reference position for mounting the light diffusing lens for a substrate on which the plurality of LED elements are mounted at an element mounting position;
An adhesive transfer step of transferring an adhesive for fixing the light diffusion lens to the element mounting position of the substrate to the light diffusion lens;
Based on the mounting reference position detected in the mounting reference position detection step, a lens mounting step of mounting the light diffusing lens on each LED element and contacting the adhesive,
A method of manufacturing an LED illumination board, comprising: an adhesive curing step of curing the adhesive by heating the substrate after the lens mounting step and fixing the light diffusion lens to the substrate.   2. The method of manufacturing an LED illumination board according to claim 1, wherein, in the mounting reference position detecting step, the mounting reference position is detected based on a position detection result obtained by optically detecting the position of the LED element.   2. The LED illumination board according to claim 1, wherein, in the mounting reference position detecting step, the mounting reference position is detected based on a brightness center detection result obtained by detecting a brightness center of illumination light emitted from the LED element. Manufacturing method.

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