JP2010139630A - Display apparatus and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display apparatus that prevents light-emitting elements from being displaced relative to a substrate, and to provide a method for manufacturing the same. <P>SOLUTION: When a plurality of LED packages 20 are reflow-mounted on the substrate 10 of the display apparatus 1, the LED packages 20 are pressed against the substrate 10 by use of a thin plate 30. Each package has two legs 21 projecting lengthwise. By pressing the upper surfaces of the legs by using the horizontal plate portion of the thin plate, the LED packages are prevented from floating and being displaced during a reflow-soldering step. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display device and a manufacturing method thereof.

Reflow mounting is known as a method of fixing a large number of packaged LED elements on a substrate at a time. However, when this reflow mounting is performed (when the reflow furnace is passed with the terminal portion of the LED element placed on the electrode portion of the substrate to which the solder paste is applied), the LED element is lifted and a positional deviation occurs. There is. As a technique for solving this, a technique for forming electrode portions on both surfaces of a substrate or increasing the area of an electrode portion in contact with the substrate is disclosed in the following publication.
JP 2003-78176 A

  However, since the temperature when reflow mounting the LED element on the substrate is high, even if the technique of the above publication is adopted, the solder paste applied to the electrode part of the substrate melts, the LED element floats, and the position is displaced. May occur.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a display device and a manufacturing method thereof that can prevent the mounting position of the light emitting element from being shifted from the substrate.

  In order to solve the above problems, the invention described in claim 1 includes a substrate, a plurality of light emitting elements reflow-soldered on the substrate, and a pressing member that presses the plurality of light emitting elements against the substrate. And

  According to a second aspect of the present invention, in the display device according to the first aspect, the pressing member is a thin wire or a thin plate made of a material having good thermal conductivity, and an insulating process is performed on the surface thereof. Features.

  According to a third aspect of the present invention, in the display device according to the second aspect, the surface of the thin wire or the thin plate is black.

  According to a fourth aspect of the present invention, in the display device according to the second or third aspect, the thin plate is disposed so as to press each end of the plurality of light emitting elements against the substrate. .

  According to a fifth aspect of the present invention, in the display device according to any one of the first to fourth aspects, the substrate is covered with a transparent or translucent plate, and the plurality of light emitting elements are shielded from the outside. It is characterized by that.

  According to a sixth aspect of the present invention, in the display device according to the fifth aspect, a resin having a predetermined refractive index is sandwiched between the plurality of light emitting elements and the transparent or translucent plate. And

  The invention according to claim 7 is the display device according to any one of claims 1 to 6, wherein the plurality of light emitting elements are LEDs.

  The invention according to claim 8 is a first step of arranging a plurality of light emitting elements on a substrate coated with a solder paste, and a pressing member that holds each of the plurality of light emitting elements against the substrate after the first step. A second step of fixing the plurality of light emitting elements to the substrate by heating the solder paste after the second step.

  According to the present invention, it is possible to prevent the mounting position of the light emitting element with respect to the substrate from being displaced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a display device 1 according to a first embodiment of the present invention. FIG. 1A is a perspective view showing a state in which an LED package 20 is arranged on a substrate 10, and FIG. FIG. 3 is a conceptual diagram showing a cross section taken along the line AA of FIG. 1B. 1A and 1B show a part of the substrate 10 (the same applies to the following embodiments).

  The display device 1 includes a substrate 10, a plurality of LED packages (light emitting elements) 20 to be reflow-soldered on the substrate 10, and a thin plate (pressing member) 30 that presses the plurality of LED packages 20 against the substrate 10. .

  The LED package 20 has a substantially rectangular parallelepiped shape, and an LED chip is accommodated therein. The LED package 20 is formed with two legs 21 projecting in the longitudinal direction. An LED side electrode 22 is provided on the lower surface of the leg portion 21. The LED side electrode 22 is fixed (soldered) to the substrate side electrode 11 provided on the upper surface of the substrate 10 with solder 23.

  The thin plate 30 is disposed between the plurality of LED packages 20. The thin plate 30 has a horizontal plate portion 30b and a vertical support portion 30a formed integrally with the lower surface of the horizontal plate portion 30b. The horizontal plate portion 30 b of the thin plate 30 is placed on the upper surface of the leg portion 21, and the horizontal plate portion 30 b is fixed to the upper surface of the substrate 10. By pressing the upper surface of the leg portion 21 with the horizontal plate portion 30b of the thin plate 30, the reflow soldering process may cause the LED package 20 to float and shift its position or cause a so-called Manhattan phenomenon in which the LED package 20 stands up. Can be prevented.

  The thin plate 30 is made of a material having good thermal conductivity, and the surface of the thin plate 30 is subjected to insulation processing. Therefore, since heat generated in the LED package 20 when the display device 1 is used can be efficiently released, the operation of the LED package 20 can be kept stable and the life of the LED package 20 can be extended. .

  The surface of the thin plate 30 is preferably black. By doing in this way, it functions also as a black matrix and the image displayed on the display device 1 becomes clearer.

  Further, after the reflow soldering process, it is preferable to cover the substrate 10 with a transparent or semi-transparent resin (silicone resin, epoxy resin, etc.) or a glass plate (not shown) to block the plurality of LED packages 20 from the outside. . By doing so, the LED package 20 is not directly exposed to the outside environment, so that the operation of the LED package 20 can be kept stable and the life can be extended.

  Moreover, it is preferable to sandwich a resin (not shown) having a predetermined refractive index between the plurality of LED packages 20 and a transparent or translucent plate. By doing in this way, the loss of the light emitted from the LED package 20 can be minimized and the light transmission can be improved.

  Next, a method for manufacturing the display device 1 will be described.

  First, a plurality of LED packages 20 are arranged on a substrate 10 on which a solder paste (not shown) is applied to the substrate-side electrode 11 by a dispenser or the like (first step). At this time, the LED side electrode 22 of the LED package 20 is placed on the substrate side electrode 11 of the substrate 10.

  After the first step, the thin plate 30 is fixed on the substrate 10 (second step).

  At this time, the vertical support portion 30a of the thin plate 30 is fixed on the substrate 10 with an adhesive.

  After the second step, the substrate 10 is passed through a reflow furnace heated to a predetermined temperature (for example, 300 ° C.) to heat the solder paste, and the plurality of LED packages 20 are fixed to the substrate 10 by soldering (third) Process).

  In addition, when the soldering is defective, it can be re-soldered by using a rework device or the like as necessary.

  According to this embodiment, since the plurality of LED packages 20 are pressed against the substrate 10 by the thin plate 30, it is possible to prevent displacement of the position of the LED package 20 with respect to the substrate 10 in the reflow soldering process.

  2A and 2B show a display device 101 according to a second embodiment of the present invention. FIG. 2A is a perspective view showing a state in which the LED package 120 is arranged on the substrate 10, and FIG. FIG. 4A is a conceptual diagram showing a cross section taken along line BB in FIG. 2B, and FIG. 4B is a line CC in FIG. 2B. FIG. 6 is a conceptual diagram showing a cross-section along the line, and the same reference numerals are given to portions common to the first embodiment, and description thereof is omitted.

  This embodiment is different from the first embodiment in that the shape of the LED package (light emitting element) 120 is different from the shape of the LED package 20.

  Two LED side electrodes 122 having an L-shaped cross section are provided at the lower portion of the LED package 120. The LED side electrode 122 is fixed (soldered) to the substrate side electrode 11 of the substrate 10 with solder 23.

  The thin plate 30 is disposed between the plurality of LED packages 120. The thin plate 30 has a horizontal plate portion 30b and a vertical support portion 30a formed integrally with the lower surface of the horizontal plate portion 30b. The horizontal plate portion 30 b of the thin plate 30 is placed on the upper surface of the LED package 120, and the horizontal plate portion 30 b is fixed to the upper surface of the LED package 120. By pressing the upper surface of the LED package 120 with the horizontal plate portion 30b of the thin plate 30, the LED package 120 may be lifted and shifted in the reflow soldering process, or a so-called Manhattan phenomenon in which the LED package 120 stands up may occur. Can be prevented.

  The thin plate 30 is made of a material having good thermal conductivity, and is similar to the first embodiment in that the surface of the thin plate 30 is insulated and the surface of the thin plate 30 is black.

  Note that the manufacturing method of the display device 101 is the same as the manufacturing method of the display device 1, and therefore the description thereof is omitted.

  According to this embodiment, the same effects as those of the first embodiment can be obtained.

  FIG. 5 shows a display device 201 according to a third embodiment of the present invention. FIG. 5 (a) is a plan view showing a state in which the LED bare chip 220 is arranged on the substrate 10, and FIG. 5 (b) is a diagram of FIG. It is a conceptual diagram which shows the cross section along a DD line, and attaches | subjects the same code | symbol to the part which is common in 1st Embodiment, and abbreviate | omits the description.

  This embodiment is different from the first embodiment in that an LED bare chip (light emitting element) 220 that does not use a package instead of the LED package 20 is arranged on the substrate 10 (not shown in FIG. 5A).

  The LED bare chip 220 has a rectangular parallelepiped shape. Two LED side electrodes 222 are provided on the lower surface of the LED bare chip 220. The LED side electrode 222 is fixed (soldered) to the substrate side electrode 11 of the substrate 10 with solder bumps 23.

  The thin plate 230 is disposed between the plurality of LED packages 20. The thin plate 30 has a horizontal plate portion 30b and a vertical support portion 30a formed integrally with the lower surface of the horizontal plate portion 30b. The horizontal plate portion 30 b of the thin plate 30 is placed on the upper surface of the LED bare chip 220, and the horizontal plate portion 30 b is fixed to the upper surface of the LED bare chip 220. By pressing the upper surface of the LED bare chip 220 with the horizontal plate portion 30b of the thin plate 30, the reflow soldering process may cause the LED package 120 to float and shift its position, or the so-called Manhattan phenomenon in which the LED bare chip 220 stands up may occur. Can be prevented.

  The thin plate 230 is made of a material having good thermal conductivity, and is similar to the first embodiment in that the surface of the thin plate 230 is insulated and the surface of the thin plate 230 is black.

  According to this embodiment, the same effects as those of the first embodiment can be obtained.

  FIG. 6 is a perspective view showing a state in which the LED package 20 of the display device 301 according to the fourth embodiment of the present invention is mounted on the substrate 10, and parts common to the first embodiment are denoted by the same reference numerals. Description is omitted.

  This embodiment is different from the first embodiment in that the LED package 20 is pressed against the substrate 10 with a thin wire 130 instead of the thin plate 30.

  The display device 301 includes a substrate 10, a plurality of LED packages 20 to be reflow-soldered on the substrate 10, and thin wires (pressing members) 130 that press the plurality of LEDs 20 against the substrate 10. The thin wire 130 is, for example, a piano wire.

  The fine wires 130 are stretched so as to press the leg portions 21 of the LED packages 20 arranged in the lateral direction on the substrate 10 against the substrate 10.

  According to this embodiment, the same effects as those of the first embodiment can be obtained.

FIG. 1 is a diagram showing a display device according to a first embodiment of the present invention. FIG. 2 is a diagram showing a display device according to a second embodiment of the present invention. FIG. 3 is a conceptual diagram showing a cross section taken along the line AA of FIG. 4A is a conceptual diagram showing a cross section taken along the line BB in FIG. 2B, and FIG. 4B is a conceptual diagram showing a cross section taken along the line CC in FIG. 2B. FIG. 5 is a diagram showing a display device according to a third embodiment of the present invention. FIG. 6 is a perspective view showing a state in which an LED package of a display device according to a fourth embodiment of the present invention is mounted on a substrate.

Explanation of symbols

  1, 101, 201, 301: Display device, 10: Substrate, 20, 120: LED package (light emitting element), 30, 230: Thin plate (pressing member), 130: Fine wire (pressing member), 220: LED bare chip (light emitting) element).

Claims (8)

A substrate,
A plurality of light emitting elements to be reflow soldered on the substrate;
A display device comprising: a pressing member that presses the plurality of light emitting elements against the substrate.   The display device according to claim 1, wherein the pressing member is a thin wire or a thin plate made of a material having good thermal conductivity, and an insulating process is performed on a surface thereof.   The display device according to claim 2, wherein a surface of the thin wire or the thin plate is black.   The display device according to claim 2, wherein the thin plate is disposed so as to press the end portions of the plurality of light emitting elements against the substrate.   5. The display device according to claim 1, wherein the substrate is covered with a transparent or translucent plate, and the plurality of light emitting elements are shielded from the outside world.   6. The display device according to claim 5, wherein a resin having a predetermined refractive index is sandwiched between the plurality of light emitting elements and the transparent or translucent plate.   The display device according to claim 1, wherein the plurality of light emitting elements are LEDs. A first step of arranging a plurality of light emitting elements on a substrate coated with a solder paste;
After the first step, a second step of fixing on the substrate a pressing member that presses each of the plurality of light emitting elements to the substrate;
And a third step of heating the solder paste and fixing the plurality of light emitting elements to the substrate after the second step.

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