JP2010186748A - Backlight unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a backlight unit including light-emitting diodes with pitches kept at a constant distance. <P>SOLUTION: The backlight unit includes a module board including a conductive layer with a circuit pattern, a light-emitting module including light-emitting diodes mounted on the conductive layer, and a fastening means which is formed in the module board and is inserted into a fastening hole separated from the conductive layer at a specific distance. The pitches between the light-emitting diodes are maintained at a constant distance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a backlight unit.

  With the development of the electronic equipment industry, development of various compact and energy-saving display devices is progressing, and liquid crystal display devices (LCD) that reflect this trend are monitors, televisions, mobile communication terminals, etc. It is in the limelight as a display device.

  Since the liquid crystal display device cannot emit light by itself, it is common to provide a backlight serving as a light source for generating light on the back of the LCD panel. At this time, the backlight generates white light so that the color of the image embodied by the LCD panel can be reproduced close to the actual color.

  Recently, instead of CCFL (Cold Cathode Fluorescent Lamp), a backlight unit including a light emitting diode has been used. In the case of a backlight unit including a light emitting diode, electric consumption is reduced and the backlight unit can be used for a long time.

  FIG. 1 is a plan view of a general backlight unit. As shown in FIG. 1, the light emitting diode 10 is connected by a conductor 20 and a conductor 30. At this time, the hole 40 for inserting the fastening means is located in the region between the light emitting diodes 10.

  Since the holes 40 are positioned between the light emitting diodes 10 as described above, the pitch between the light emitting diodes 10 is not constant. That is, when the hole 40 is located between the adjacent light emitting diodes 10, the pitch P1 between the light emitting diodes 10 located on both sides of the hole 40 increases. Therefore, the pitch P2 between the light emitting diodes 10 located on both sides of the region where the hole 40 is not located is smaller than the pitch P1.

  Thus, if the pitch between the light emitting diodes 10 is not maintained constant, a difference in the amount of light incident on the LCD panel occurs, which affects the image quality of the LCD panel.

  The present invention is to provide a backlight unit including a light emitting diode whose pitch is kept constant.

  The present invention relates to a module substrate including a conductive layer having a circuit pattern, and a light emitting module including a light emitting diode mounted on the conductive layer, and a fastening hole formed inside the module substrate and separated from the conductive layer by a predetermined distance. Fastening means inserted into the.

  The present invention includes a module substrate including a conductive layer having a circuit pattern, a light emitting module including a light emitting diode mounted on the conductive layer, and fastening means inserted into a fastening hole formed in the module substrate. The pitch between the light emitting diodes is kept constant.

  In the present invention, since the fastening holes include fastening holes that are separated from the conductive layer by a predetermined distance, the pitch between the light emitting diodes can be maintained constant.

The drawing of a general backlight unit is shown. It is side sectional drawing of the backlight unit which concerns on 1st Example. It is a sectional side view of the backlight unit according to the second embodiment. It is a sectional side view of the backlight unit which concerns on 3rd Example of this invention. It is a sectional side view of the backlight unit which concerns on 4th Example of this invention.

    Hereinafter, embodiments will be described with reference to the accompanying drawings.

    FIG. 2 is a diagram illustrating a backlight unit according to the first embodiment.

    Referring to FIG. 2, the backlight unit 100 includes a light emitting module 130, and may further include a bottom cover 110 and a heat dissipating pad 120 positioned between the bottom cover 110 and the module substrate 136 of the light emitting module 130. An optical sheet (not shown) and a display panel such as an LCD panel may be disposed on the backlight unit 100.

  The bottom cover 110 may have a recess for receiving the light emitting module 130. The bottom cover 110 functions as a heat sink, and the materials thereof are aluminum (Al), magnesium (Mg), zinc (Zn), titanium (Ti), tantalum (Ta), hafnium (Hf), niobium (Nb). However, the embodiment is not limited to this.

  The heat dissipating pad 120 is attached on the bottom cover 110 as a pad made of silicone, and absorbs and releases heat generated from the light emitting module 130. The heat dissipation pad 120 is attached between the light emitting module 130 and the bottom cover 110 and dissipates heat from the light emitting module 130 or conducts heat through the bottom cover 110. Further, the heat dissipating pad 120 can absorb an impact applied from the outside. The heat dissipating pad 120 may be attached to the bottom cover 110 with an adhesive.

  The light emitting module 130 includes a module substrate 136 and a light emitting diode 140. The module substrate 136 is a metal base substrate such as an aluminum base substrate, and includes one or more heat dissipation plates 131, one or more insulating layers 134, and a thin copper layer. The conductive layer 135 is included. The one or more heat radiating plates 131 and the one or more insulating layers 134 are alternately arranged, and the conductive layer 135 is positioned on the insulating layer 134.

  The heat dissipating plate 131 may be made of aluminum, and its thickness TO may be 0.6 mm or greater and 1.0 mm or less, and the thickness TO may be changed in consideration of heat dissipation efficiency. The insulating layer 134 is located between the heat dissipation plate 141 and the conductive layer 135 and electrically insulates the heat dissipation plate 141 and the conductive layer 135.

  The conductive layer 135 has a predetermined circuit pattern. A light emitting diode 140 may be mounted on the conductive layer 135, and an LED array including a plurality of light emitting diodes 140 may be mounted. The light emitting diode 140 may be mounted on the conductive layer 135 in a chip form or a package form, and emits light of a desired color.

  The light emitting module 130 is attached to the heat dissipating pad 120 with an adhesive and is fixed to the bottom cover 110 by the fastening means 150. At this time, the fastening means 150 may be a screw.

  At least one fastening hole 151 communicating with the bottom cover 110, the heat radiating pad 120, and the lower part of the heat radiating plate 131 is formed, and a screw thread 153 can be formed around the fastening hole 151 of the heat radiating plate 131. At this time, the depth D of the fastening hole 151 is smaller than the total thickness of the bottom cover 110, the heat dissipation pad 120, and the heat dissipation plate 131. Accordingly, the end of the fastening hole 151 can be positioned inside the heat dissipation plate 131.

  The depth T1 of the fastening hole 151 formed in the heat radiating plate 131 is smaller than the thickness TO of the heat radiating plate 131. At this time, a depth T1 of a part of the fastening hole 151 formed in a region between one surface of the module substrate 136 located on the bottom cover 110 side and the insulating layer 134 located on the conductive layer 135 side The distance between one surface of 136 and the insulating layer 134 may be 1/3 or more and 2/3 or less.

  For example, as shown in FIG. 2, the depth T1 of the fastening hole 151 formed in the region between the heat dissipation pad 120 and the insulating layer 134 is the distance between the heat dissipation pad 120 and the insulating layer 134, that is, The thickness TO of the heat radiating plate 131 may be 1/3 or more and 2/3 or less. Accordingly, the depth T1 of the fastening hole 151 formed in the heat dissipation plate 131 can be 1/3 or more and 2/3 or less of the thickness TO of the heat dissipation plate 131.

  When the depth T1 of the fastening hole 151 formed in the heat radiating plate 131 is 1/3 or more of the thickness TO of the heat radiating plate 131, the fastening means 150 can be fastened to the heat radiating plate 131 stably. When the depth T1 of the fastening hole 151 formed in the heat radiating plate 131 is 2/3 or less of the thickness TO of the heat radiating plate 131, the fastening means 150 may prevent the insulating layer 134 from being broken.

  Thus, the depth D of the fastening hole 151 is smaller than the total thickness of the bottom cover 110, the heat radiating pad 120, and the heat radiating plate 131, or the depth T1 of the fastening hole 151 formed in the heat radiating plate 131 is the heat radiating plate 131. The fastening hole 151 is separated from the conductive layer 135 having a circuit pattern by a predetermined distance. The fastening means 150 is formed inside the module substrate 136 and is inserted into a fastening hole that is separated from the conductive layer 135 by a predetermined distance.

  Therefore, since the holes 40 shown in FIG. 1 do not exist in the backlight unit according to the embodiment of the present invention, the pitch between the light emitting diodes 140 can be kept constant.

  When the fastening unit 150 is fastened through the fastening hole 151, the fastening unit 150 is inserted into the fastening hole 151 formed in a part of the bottom cover 110, the heat radiating pad 120, and the heat radiating plate 131, and the light emitting module 130 is fixed to the bottom cover 110. Is done. At this time, the fastening means 150 can be adjusted in depth by the depth T1 of the fastening hole 151, and electrical contact between the fastening means 150 and the conductive layer 135 can be blocked.

  In the embodiment of the present invention, since there is no hole 40 as shown in FIG. 1, the fastening force of the fastening means 150 can be weakened. Therefore, the screw thread 153 around the fastening hole 151 can improve the fastening force of the fastening means 150.

  When the light emitting module 130 is closely attached and fixed to the bottom cover 110, the light emitting module 130 is prevented from flowing such as floating and twisting, and problems such as light quantity and hot spots can be prevented. Further, the light emitting module 130 and the bottom cover 110 are in close contact with each other, so that the heat of the light emitting module 130 can be effectively released.

  FIG. 3 is a side sectional view showing a backlight unit according to a second embodiment of the present invention. In the description of the second embodiment, the same parts as those in the first embodiment will be referred to in the first embodiment, and redundant description will be omitted.

  Referring to FIG. 3, the backlight unit 100A includes a module substrate 136A including a plurality of heat radiation plates 131A and 131B and a plurality of insulating layers 132 and 134 in a light emitting module 130A.

  The module substrate 136A of the light emitting module 130A includes a first heat radiating plate 131A, a first insulating layer 132, a second heat radiating plate 131B, a second insulating layer 134, and a conductive layer 135.

  The first heat radiating plate 131 </ b> A is in contact with the heat radiating pad 120. The first insulating layer 132 is disposed between the first heat radiating plate 131A and the second heat radiating plate 131B, and the second insulating layer 134 is disposed on the second heat radiating plate 131B.

  The first and second heat radiating plates 131A and 131B may be made of an aluminum material, and the first insulating layer 132 is disposed between the first and second heat radiating plates 131A and 131B. At this time, the module substrate 136A may include one or more second heat dissipation plates 131B and one or more second insulating layers 134. When the module substrate 136A includes a plurality of second heat dissipation plates 131B and a second insulating layer 134, the plurality of second heat dissipation plates 131B and the second insulating layers 134 can be alternately stacked.

  As described above, since the insulating layer 132 is positioned between the heat radiation plates 131A and 131B, the insulation between the light emitting module 130A and the module substrate 136A can be stabilized.

  The fastening hole 151 may be communicated with the bottom cover 110, the heat radiating pad 120, and the first heat radiating plate 131A. In addition, the fastening hole 151 may be connected to the first insulating layer 132 as well as the bottom cover 110, the heat radiating pad 120, and the first heat radiating plate 131A, and the bottom cover 110, the heat radiating pad 120, the first heat radiating plate 131A, The first insulating layer 132 and the second heat radiating plate 131B can communicate with each other.

  At this time, the depth D of the fastening hole 151 is smaller than the total thickness of the bottom cover 110, the heat dissipation pad 120, the plurality of heat dissipation plates 131A and 131B, and the plurality of insulating layers 132 and 134. As a result, the end of the fastening hole 151 is located in the first heat dissipating plate 131A or the second heat dissipating plate 131B or in the first insulating layer 132 located between the adjacent first and second heat dissipating plates. can do.

  Also, the fastening formed on the first heat radiating plate 131A, formed on the first heat radiating plate 131A and the first insulating layer 132, or formed on the first heat radiating plate 131A, the first insulating layer 132 and the second heat radiating plate 131B. The depth T2 of the hole 151 is smaller than the total thickness of the first heat radiating plate 131A, the first insulating layer 132, and the second heat radiating plate 131B.

  Also in the second embodiment of the present invention, a part of the fastening hole 151 formed in the region between one surface of the module substrate 136 positioned on the bottom cover 110 side and the insulating layer 134 positioned on the conductive layer 135 side is also provided. The depth T <b> 2 may be 1/3 or more and 2/3 or less between the one surface of the module substrate 136 and the insulating layer 134.

  For example, the depth T2 of the fastening hole 151 formed in the first heat radiating plate 131A, the depth T2 of the fastening hole 151 formed in the first heat radiating plate 131A and the first insulating layer 132, or the first heat radiating plate 131A, The depth T2 of the fastening hole 151 formed in the first insulating layer 132 and the second heat radiating plate 131B is 1/3 or more of the total thickness of the first heat radiating plate 131A, the first insulating layer 132, and the second heat radiating plate 131B. It can be 2/3 or less.

  When the depth T2 of the fastening hole 151 is 1/3 or more of the total thickness, the fastening means 150 can be stably fastened to the module substrate 136A. In addition, when the depth T2 of the fastening hole 151 is 2/3 or less of the total thickness, the insulating layer 134 may be prevented from being broken by the fastening means 150.

  As described above, the depth D of the fastening hole 151 is smaller than the total thickness of the bottom cover 110, the heat dissipation pad 120, and the module substrate 136A, or the depth T2 of the fastening hole 151 formed in the module substrate 136A is the module. If the thickness is smaller than the thickness of the substrate 136 </ b> A, the fastening hole 151 is separated from the conductive layer 135. Therefore, since the holes 40 shown in FIG. 1 are not present in the backlight unit according to the second embodiment of the present invention, the pitch between the light emitting diodes 140 can be maintained constant.

  A fastening hole 151 may be formed in the entire thickness T2 of the first heat radiating plate 131A, and a screw thread 153 may be formed around the fastening hole 151. The first heat radiating plate 131A may have a thickness T2 of about 0.6 mm to 1.0 mm.

  The fastening means 150 can be inserted through the bottom cover 110 and the fastening hole 151 of the heat radiating pad 120 and fastened along the thread 153 of the fastening hole 151 of the first heat radiating plate 131A. Accordingly, the bottom cover 110, the heat radiating pad 120, and the first heat radiating plate 131A are fastened together using the fastening means 150, so that the light emitting module 130A can be fixed to the bottom cover 110. In addition, when the fastening means 150 is fastened, the first insulating layer 132, the second heat radiating plate 131B, and the second insulating layer 134 disposed on the first heat radiating plate 131A prevent problems due to overtightening of screws. Can do.

  In the embodiment, by providing a screw type light emitting module substrate, the module substrate can be prevented from being lifted or twisted, and the heat dissipation effect can be improved.

  4 and 5 are side sectional views of backlight units according to third and fourth embodiments of the present invention. In the description of the third and fourth embodiments, the same parts as those of the first and second embodiments are referred to by referring to the first and second embodiments, and the duplicate description is omitted. I will do it.

  As shown in FIGS. 4 and 5, unlike the first and second embodiments, the third and fourth embodiments of the present invention have no thread on the side surface of the fastening hole 151, and the heat radiating plate. The adhesive layer 300 is located between the 131 and the heat dissipation pad 120 or between the first heat dissipation plate 131 </ b> A and the heat dissipation pad 120. The adhesive layer 300 may be formed of an adhesive or an adhesive sheet between the module substrates 136 and 136A and the bottom cover 110. Since there is no screw thread in this way, the diameter of the fastening hole 151 is not repeatedly increased or decreased due to the unevenness due to the screw thread, but can be kept constant or gradually decreased as it is closer to the conductive layer 135.

  For example, when the diameter of the fastening hole 151 is maintained constant, the fastening hole 151 and the fastening means 150 may have a cylindrical shape. In addition, when the diameter of the fastening hole 151 is gradually reduced, the fastening hole 151 and the fastening unit 150 may have a conical shape.

  The adhesive layer 300 is for compensating for a decrease in fastening force due to the absence of a thread, and increases the coupling force between the heat radiating plate 131 and the heat radiating pad 120 or heat radiating between the first heat radiating plate 131A and the heat radiating plate 131A. The bonding force between the pad 120 and the pad 120 can be increased.

  As described above, in the third and fourth embodiments of the present invention, a process for forming a screw thread is not necessary in the manufacturing process of the backlight unit, and therefore the pitch between the light emitting diodes 140 is constant. The manufacturing process of the backlight unit is simplified while being maintained.

Although the embodiments have been mainly described above, this is merely an example, and is not intended to limit the present invention. Any person having ordinary knowledge in the field to which the present invention belongs can be used. It is understood that various modifications and applications not exemplified above are possible without departing from the above characteristics. For example, each component specifically shown in the embodiments can be implemented by being modified. Such differences in modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

Claims (16)

A module substrate including a conductive layer having a circuit pattern, and a light emitting module including a light emitting diode mounted on the conductive layer;
And a fastening unit that is formed inside the module substrate and is inserted into a fastening hole that is spaced apart from the conductive layer by a predetermined distance.   The backlight unit according to claim 1, wherein a screw thread is formed in the fastening hole, and the fastening means is a screw. The module substrate includes an insulating layer located on the conductive layer side,
The depth of a part of the fastening hole formed in the region between one surface of the module substrate and the insulating layer is 1 / of the distance between the one surface of the module substrate and the insulating layer. The backlight unit according to claim 1, wherein the backlight unit is 3 or more and 2/3 or less. The module substrate includes one or more heat dissipation plates and one or more insulating layers,
The one or more heat dissipation plates and the one or more insulating layers are alternately arranged,
The backlight unit according to claim 1, wherein the conductive layer is located on the insulating layer.   The backlight unit according to claim 4, wherein the heat radiating plate includes an aluminum material.   5. The backlight unit according to claim 4, wherein an end portion of the fastening hole is located inside the heat radiating plate or in the insulating layer located between the adjacent heat radiating plates. 6. Further comprising a bottom cover for storing the light emitting module,
The diameter of the fastening hole is kept constant as it is closer to the conductive layer, or gradually decreases,
The backlight unit according to claim 1, further comprising an adhesive layer positioned between the module substrate and the bottom cover.   The backlight unit according to claim 1, further comprising a bottom cover in which the light emitting module is accommodated, and a heat dissipating pad positioned between the module substrate and the bottom cover. A module substrate including a conductive layer having a circuit pattern, and a light emitting module including a light emitting diode mounted on the conductive layer;
Fastening means to be inserted into a fastening hole formed inside the module substrate,
The backlight unit is characterized in that a pitch between the light emitting diodes is maintained constant.   The backlight unit according to claim 9, wherein a thread is formed in the fastening hole, and the fastening means is a screw. The module substrate includes an insulating layer located on the conductive layer side,
The depth of a part of the fastening hole formed in the region between one surface of the module substrate and the insulating layer is 1 / of the distance between the one surface of the module substrate and the insulating layer. The backlight unit according to claim 9, wherein the backlight unit is 3 or more and 2/3 or less. The module substrate includes one or more heat dissipation plates and one or more insulating layers,
The one or more heat dissipation plates and the one or more insulating layers are alternately disposed,
The backlight unit according to claim 11, wherein the conductive layer is located on the insulating layer.   The backlight unit according to claim 12, wherein the heat radiating plate includes an aluminum material.   The backlight unit according to claim 12, wherein an end portion of the fastening hole is located in the heat dissipation plate or in the insulating layer located between the adjacent plates. Further comprising a bottom cover for storing the light emitting module,
The diameter of the fastening hole is kept constant as it is closer to the conductive layer, or gradually decreases,
The backlight unit according to claim 9, further comprising an adhesive layer positioned between the module substrate and the bottom cover.   The backlight unit according to claim 9, further comprising: a bottom cover in which the light emitting module is accommodated; and a heat dissipating pad positioned between the module substrate and the bottom cover.