Light source unit for vehicle lamp and vehicle lamp

Abstract

Provided are a light source unit for a vehicle lamp and a vehicle lamp, which can improve heat dissipation performance. The light source unit for a vehicle lamp comprises: a circuit substrate (3) provided with a light emitting element (2) and a driving circuit for driving the light emitting element (2); and a heat sink (5) which dissipates heat (W1) generated by the light emitting element (2) to the outside via a substrate mounting portion (4) on which the circuit substrate (3) is mounted, wherein at least a portion of the circuit substrate (3) opposite to the light emitting element (2) is composed of an insulating heat transfer component (20).

Description

Technical Field

[0001] The present invention relates to a light source unit for a vehicle lamp and a vehicle lamp. Background Art

[0002] In recent years, with the development of high brightness and low cost of light-emitting diodes (LEDs), the number of lamps using light-emitting elements such as LEDs as light sources has gradually increased. LEDs have the advantages of long life and low power consumption. On the other hand, high temperature will lead to reduced luminous efficiency and shortened life. Therefore, a heat sink is needed to efficiently dissipate the heat generated by the LED to the outside.

[0003] For example, the following patent document 1 proposes a light source unit, in which a circuit substrate on which an LED and a driving circuit for driving the LED are mounted is mounted on a heat sink, and a lamp holder with a coupler is detachably mounted in a mounting hole provided on the back side of a lamp body, and the lamp holder with a coupler mounts the heat sink and a connector portion electrically connected to the circuit substrate as a whole. Such a light source unit is preferably used as a replaceable (substitute) light source such as a taillight of a vehicle that emits red light.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-085300 Summary of the invention

[0007] However, in the above-mentioned light source unit, since the LED or the electronic components constituting the driving circuit are mounted on the same surface of the circuit substrate, it is necessary to efficiently dissipate the heat generated by the LED or the electronic components to the outside through the heat sink. In particular, when the light source unit is applied to high-brightness lamps such as brake lamps, high heat dissipation performance is required while maintaining the luminous brightness of the LED.

[0008] Furthermore, in the light source unit, it is necessary not only to efficiently dissipate heat generated by the LED or electronic components to the outside through the heat sink, but also to prevent the temperature of the LED from rising due to residual heat from the electronic components mounted on the same surface of the circuit board.

[0009] The present invention has been made in view of the above-mentioned conventional situation, and an object of the present invention is to provide a vehicle lamp light source unit capable of improving heat dissipation performance, and a vehicle lamp having the vehicle lamp light source unit.

[0010] In order to achieve the above-mentioned object, the present invention provides the following means.

[0011] (1) A light source unit for a vehicle lamp, characterized in that the light source unit for a vehicle lamp comprises:

[0012] a circuit substrate provided with a light emitting element and a driving circuit for driving the light emitting element; and

[0013] a heat sink that dissipates heat generated by the light emitting element to the outside via a substrate mounting portion on which the circuit substrate is mounted,

[0014] At least a portion of the circuit substrate facing the light emitting element is formed of an insulating heat transfer member.

[0015] (2) The light source unit for a vehicle lamp according to (1) above is characterized in that:

[0016] The heat transfer member is made of a material having a higher thermal conductivity than that of the insulating resin substrate constituting the circuit substrate.

[0017] (3) The light source unit for a vehicle lamp according to (2) above is characterized in that:

[0018] The heat transfer component is made of aluminum nitride.

[0019] (4) The vehicle lamp light source unit according to (2) or (3) above, characterized in that:

[0020] The heat transfer member is disposed at a position where a portion of the insulating resin substrate is removed.

[0021] (5) The light source unit for a vehicle lamp according to (4) above is characterized in that:

[0022] The heat transfer member is arranged inside an opening that opens a portion of the insulating resin substrate, and an insulating adhesive layer is provided between the heat transfer member and the opening.

[0023] (6) The vehicle lamp light source unit according to any one of (2) to (5), wherein:

[0024] The circuit substrate has a first wiring pattern arranged on one surface of the insulating resin substrate.

[0025] At least a portion of the first wiring pattern is located inside a region overlapping the heat transfer member in a plan view, and is electrically connected to the light emitting element.

[0026] (7) The vehicle lighting light source unit according to (6) above is characterized in that:

[0027] The circuit substrate has a second wiring pattern and a connection pattern, wherein the second wiring pattern is arranged on one surface of the insulating resin substrate and is electrically connected to the electronic component constituting the drive circuit, and the connection pattern connects the first wiring pattern and the second wiring pattern.

[0028] The connection pattern is formed to have a narrower width than the first wiring pattern and the second wiring pattern.

[0029] (8) The light source unit for a vehicle lamp according to (7) above is characterized in that:

[0030] The circuit substrate has:

[0031] a plurality of through holes which are arranged to penetrate the insulating resin substrate and are thermally connected to the second wiring pattern; and

[0032] The heat transfer pattern is disposed on the other surface of the insulating resin substrate and is thermally connected to the plurality of through holes.

[0033] (9) The light source unit for a vehicle lamp according to (8) above is characterized in that:

[0034] The plurality of through holes are arranged relatively more on a side separated from a side where the light emitting element is located across a position where electronic components constituting the drive circuit are arranged.

[0035] (10) The vehicle lighting light source unit according to any one of (1) to (9), wherein:

[0036] The light emitting element is arranged inside a region overlapping with the heat transfer member when viewed from above.

[0037] The electronic components constituting the driving circuit are arranged outside a region overlapping the heat transfer member in a plan view.

[0038] (11) The vehicle lamp light source unit according to any one of (1) to (10), wherein:

[0039] The circuit substrate is mounted on the substrate mounting portion via a thermally conductive adhesive.

[0040] (12) The vehicle lighting light source unit according to any one of (1) to (11), wherein:

[0041] The heat sink has a plurality of fins protruding from a side opposite to the substrate mounting portion.

[0042] (13) The vehicle lighting light source unit according to any one of (1) to (12), wherein:

[0043] The vehicle lamp light source unit includes a socket body provided with the heat sink and a connector portion, and the connector portion is electrically connected to the circuit board via a lead terminal.

[0044] (14) A vehicle lamp, comprising the vehicle lamp light source unit according to any one of (1) to (13).

[0045] (15) The vehicle lamp according to (14) above, characterized in that:

[0046] The vehicle lamp light source unit is detachably mounted on a lamp body.

[0047] Effects of the Invention

[0048] As described above, according to the present invention, it is possible to provide a vehicle lamp light source unit capable of improving heat dissipation performance, and a vehicle lamp having such a vehicle lamp light source unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a cross-sectional view showing the structure of a vehicle lamp including a vehicle lamp light source unit according to an embodiment of the present invention.

[0050] Figure 2 It is a perspective view showing the structure of a light source unit for a vehicle lamp.

[0051] Figure 3 It is an exploded perspective view showing the structure of a light source unit for a vehicle lamp.

[0052] Figure 4 It is a front view showing the structure of the light source unit for a vehicle lamp.

[0053] Figure 5 It is along Figure 4 A cross-sectional view of a light source unit for a vehicle lamp taken along line segment AA shown in FIG.

[0054] Figure 6 It will be Figure 5 Schematic cross-sectional view of an enlarged portion of a heat sink on which a circuit substrate is mounted via a substrate mounting portion.

[0055] Figure 7 It is a plan view showing the structure of a circuit board.

[0056] Description of symbols

[0057] 1: light source unit (light source unit for vehicle lamp); 2: light emitting element; 3: circuit substrate; 4: substrate mounting portion; 5: heat sink; 6: lead terminal; 7: connector portion; 8: lamp holder body; 9: electronic component; 10: frame; 11: sealing resin; 12: wiring pattern; 12a: first wiring pattern; 12b: second wiring pattern; 12c: connection pattern; 12d: heat transfer pattern; 13: protective layer; 14: bonding wire; 15: hole portion; 16: sealing component; 17: thermally conductive adhesive; 20: heat transfer component; 30: insulating resin substrate; 31: adhesive layer; 32: through hole; 100: vehicle lamp; 101: housing; 102: lens cover; 103: lamp body; 104: gasket. DETAILED DESCRIPTION

[0058] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0059] In the drawings used in the following description, in order to make each component easier to see, the dimensions may be shown at different scales depending on the component, and the dimensional ratios of each component are not necessarily the same as the actual ones.

[0060] As one embodiment of the present invention, for example Figure 1 A vehicle lamp 100 including a vehicle lamp light source unit (hereinafter referred to as a “light source unit”) 1 will be described.

[0061] in addition, Figure 1 1 is a cross-sectional view showing the structure of a vehicle lamp 100 including the light source unit 1 .

[0062] In addition, in the drawings shown below, an XYZ orthogonal coordinate system is set, the X-axis direction is represented as the front-to-back direction (length direction) of the light source unit 1 (vehicle lamp 100), the Y-axis direction is represented as the left-right direction (width direction) of the light source unit 1 (vehicle lamp 100), and the Z-axis direction is represented as the up-down direction (height direction) of the light source unit 1 (vehicle lamp 100).

[0063] The vehicle lamp 100 of this embodiment applies the present invention to, for example, taillights and brake lights that emit red light at two corners of the rear end of a vehicle (not shown). The light source unit 1 of this embodiment is a lamp holder with a coupler that carries a replaceable (replaceable) LED lamp.

[0064] In the following description, unless otherwise specified, the words "front", "rear", "left", "right", "up", and "down" refer to directions when the vehicle lamp 100 (light source unit 1) is viewed from the front (rear of the vehicle). Therefore, directions when the vehicle is viewed from the front (front of the vehicle) are directions in which the front, rear, left, and right directions are opposite.

[0065] Specifically, if Figure 1 As shown, the vehicle lamp 100 has a structure in which the light source unit 1 of the present embodiment is housed inside a lamp body 103 . The lamp body 103 is composed of a housing 101 with an opening on the front side and a transparent lens cover 102 covering the opening of the housing 101 .

[0066] The light source unit 1 can be detachably mounted around the mounting hole 101a via an annular gasket (O-ring) 104 while its front surface is inserted into the inner side of the lamp body 103 from the mounting hole 101a provided on the back (rear) side of the housing 101 (lamp body 103).

[0067] Below, refer to Figure 2 to Figure 7 The specific structure of the light source unit 1 according to the present embodiment will be described.

[0068] in addition, Figure 2 It is a perspective view showing the structure of the light source unit 1 . Figure 3 It is an exploded perspective view showing the structure of the light source unit 1 . Figure 4 It is a front view showing the structure of the light source unit 1 . Figure 5 It is along Figure 4 sectional view of the light source unit 1 along the line segment AA shown in FIG. Figure 6 It will be Figure 5 , a cross-sectional view showing an enlarged portion of a heat sink 5 on which a circuit substrate 3 is mounted via a substrate mounting portion 4 is shown. Figure 7 It is a plan view showing the structure of the circuit board 3 .

[0069] like Figure 2 to Figure 5 As shown, the light source unit 1 of the present embodiment roughly comprises: a circuit substrate 3, which is provided with a plurality of light-emitting elements 2; and a lamp holder main body 8, which is provided with a substrate mounting portion 4 on which the circuit substrate 3 is mounted, a heat sink 5 for dissipating heat generated by the light-emitting elements 2 to the outside, and a connector portion 7 electrically connected to the circuit substrate 3 via a plurality of lead terminals 6.

[0070] The circuit board 3 is formed of a rectangular flat plate-shaped printed wiring board (PWB) with rounded corners. For example, FR-4 or the like can be used for the PWB.

[0071] A plurality of light emitting elements 2 and a plurality of electronic components 9 constituting a drive circuit for driving the plurality of light emitting elements 2 are provided on one surface (front surface) of the circuit board 3 .

[0072] The plurality of light emitting elements 2 are composed of LEDs that emit red light (hereinafter referred to as light). In addition, the LED uses a high-output type LED for vehicle lighting. In addition, in the present embodiment, four light emitting elements 2 are used. These four light emitting elements 2 are located in the approximate center of the front surface side of the circuit substrate 3, and are arranged (installed) at equal intervals at positions radially separated upward, downward, leftward, and rightward from the positions that become the center of each other (the approximate center of the circuit substrate 3).

[0073] In addition, regarding the light emitting elements 2 , in addition to the above-mentioned structure in which four light emitting elements 2 are arranged, a structure in which five light emitting elements 2 are arranged by adding one light emitting element 2 at a position that is centered between them can be adopted.

[0074] A frame 10 is provided on the front side of the circuit board 3 to reflect light emitted by the plurality of light emitting elements 2 toward the front. The frame 10 is made of a cylindrical white member and is provided on the front side of the circuit board 3 to surround the plurality of light emitting elements 2.

[0075] A transparent sealing resin 11 is provided inside the frame 10 to seal the inside of the frame 10. The upper surface of the sealing resin 11 is formed into a convex shape so as to protrude outside the frame 10. The upper surface of the sealing resin 11 is not limited to a convex shape, but may be a flat surface.

[0076] The plurality of electronic components 9 are located outside the frame 10 surrounding the plurality of light emitting elements 2, and are arranged (mounted) on the front surface side of the circuit board 3. The driving circuit may be a resistance circuit using a resistor as the electronic component 9, or a linear circuit using an IC as the electronic component 9.

[0077] A plurality of wiring patterns 12 and a protective layer 13 covering the wiring patterns 12 are provided on the front surface of the circuit substrate 3. The plurality of wiring patterns 12 form wiring for connecting a plurality of light emitting elements 2 in series or in parallel (in series in this embodiment), wiring for electrically connecting the light emitting elements 2 to the electronic component 9, and wiring for electrically connecting the electronic component 9 to a plurality of lead terminals 6. The wiring patterns 12 are made of, for example, metal foil such as copper (Cu) or gold (Au) (copper foil in this embodiment). The protective layer 13 is made of an insulating resin material such as a resist.

[0078] A plurality of bonding wires 14 for electrically connecting the light emitting element 2 and the wiring pattern 12 are provided on the front surface side of the circuit board 3. The bonding wires 14 are made of, for example, gold wires.

[0079] A plurality of holes 15 penetrating the circuit substrate 3 in the thickness direction are provided in the circuit substrate 3. In the present embodiment, three holes 15 are arranged in the width direction at positions corresponding to the three lead terminals 6 arranged parallel to the width direction. In addition, a pad portion (not shown) formed by a part of the wiring pattern 12 is provided around the hole 15.

[0080] The light source unit 1 has a structure in which the heat sink 5 and the socket body 8 are integrated by insert molding. Alternatively, the light source unit 1 may have a structure in which the heat sink 5 and the socket body 8, which are separately formed, are integrated by screwing or the like.

[0081] The heat sink 5 is made of a metal material with high electrical and thermal conductivity, such as aluminum (Al), iron (Fe), or copper (Cu). The lamp holder body 8 is made of an insulating resin material, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polyamide (PA). In addition, the lamp holder body 8 may be made of a material obtained by adding a filler with high thermal conductivity, such as carbon, ceramic, or metal, to a resin.

[0082] In the present embodiment, the heat sink 5 is made of Al with a black anodized aluminum treatment applied to the surface. The heat sink 5 has a substantially circular plate-shaped base 5a, a protrusion 5b protruding from a substantially central portion of the front surface side of the base 5a in a substantially square cross-sectional shape, and a plurality of heat sinks 5c protruding from the rear surface side of the base 5a in a longitudinal plate-shaped state arranged in the width direction.

[0083] On the other hand, the lamp holder body 8 has a roughly circular plate-shaped base 8a, a cylindrical wall portion 8b with a roughly circular cross-section protruding forward from the roughly central portion of the front surface side of the base 8a, and a through hole 8c with a roughly square cross-section that penetrates the inner side of the cylindrical wall portion 8b and the base 8a in the front-to-back direction.

[0084] In addition, a plurality of claws 8d are arranged in the circumferential direction on the outer peripheral surface of the cylinder wall portion 8b as a stopper to prevent rotation relative to the above-mentioned mounting hole 101a and as an anti-dropping member to prevent falling out of the above-mentioned mounting hole 101a. The gasket 104 is installed in a state of penetrating the cylinder wall portion 8b and in a state of contacting the base portion 8a.

[0085] The lamp holder body 8 has a through hole 8e which is located below the through hole 8c and penetrates the inner side of the cylindrical wall portion 8b and the base portion 8a in the front-rear direction, and a substantially rectangular cylindrical lamp holder portion 8f which protrudes rearward from around the through hole 8e on the back side of the base portion 8a.

[0086] The connector portion 7 has a plurality of lead terminals 6. Each lead terminal 6 is integrally mounted on the connector portion 7 in a state of penetrating a main body portion 7a of the connector portion 7 in the front-rear direction. The main body portion 7a is fitted inside the through hole 8e so that the lead terminal 6 is located inside the socket portion 8f, thereby constituting the connector portion 7.

[0087] The substrate mounting portion 4 is provided on the front surface of the inner side of the barrel wall portion 8b. The heat sink 5 and the lamp holder body 8 are integrated in a state where the protrusion 5b is fitted into the through hole 8c and the bases 5a and 8a are in contact with each other. In addition, a sealing member 16 is arranged between the end of the protrusion 5b and the through hole 8c to hermetically seal the end of the protrusion 5b and the through hole 8c. Thus, in the substrate mounting portion 4, the end of the protrusion 5b exposed from the through hole 8c and the front surface of the inner side of the barrel wall portion 8b form a continuous flat surface.

[0088] The circuit board 3 is mounted on the front surface of the board mounting portion 4 via the thermally conductive adhesive 17. Thus, the circuit board 3 is thermally connected to the heat sink 5 via the thermally conductive adhesive 17 and the board mounting portion 4. Meanwhile, the circuit board 3 is electrically insulated from the heat sink 5 in this state.

[0089] The plurality of lead terminals 6 are fixed to the land portions located around the respective holes 15 by soldering while penetrating the respective holes 15. Thus, the plurality of lead terminals 6 are electrically connected to the wiring pattern 12 of the circuit board 3.

[0090] In addition, in the present embodiment, the circuit substrate 3 is mounted on the front surface of the substrate mounting portion 4 via the above-mentioned thermally conductive adhesive 17, but it can also be configured such that the circuit substrate 3 is arranged on the front surface of the substrate mounting portion 4 via thermally conductive grease, and an additional fixing portion is provided between these circuit substrates 3 and the substrate mounting portion 4.

[0091] However, in the light source unit 1 of the present embodiment, Figure 6 and Figure 7 As shown, at least a portion of the circuit board 3 facing the light emitting element 2 is formed of an insulating heat transfer member 20 .

[0092] The heat transfer member 20 is made of, for example, aluminum nitride (AlN), silicon nitride (SiN), aluminum oxide (Al 2 O 3 ) and the like having a higher thermal conductivity than the insulating resin substrate (FR-4 in this embodiment) constituting the circuit board 3.

[0093] Among them, it is preferable that the heat transfer member 20 is made of AlN (about 200 W / m·K) having a higher thermal conductivity than the heat sink 5 made of Al (236 W / m·K). In addition, the thermal conductivity of FR-4 constituting the circuit board 3 is about 0.5 W / m·K. In addition, there is also AlN with a thermal conductivity of about 170 W / m·K.

[0094] The heat transfer member 20 is arranged at a position where a part of the insulating resin substrate 30 is removed. Specifically, the heat transfer member 20 is formed in a rectangular flat plate shape with the same thickness as the insulating resin substrate 30. On the other hand, an opening 30a having a shape corresponding to the heat transfer member 20 is provided in the insulating resin substrate 30. The heat transfer member 20 is arranged inside the opening 30a.

[0095] Furthermore, an insulating adhesive layer 31 is provided between the heat transfer member 20 and the opening 30a so as to be embedded therebetween. The adhesive layer 31 can be made of, for example, silicone resin or epoxy resin.

[0096] Thus, in the circuit board 3 , the heat transfer member 20 and the insulating resin substrate 30 are integrated. In addition, the heat transfer member 20 is formed flush with the insulating resin substrate 30 .

[0097] In addition, the heat transfer member 20 is not limited to the above-mentioned structure in which it is arranged inside the opening 30a that opens a part of the insulating resin substrate 30, and may be configured, for example, to be arranged inside a recessed portion that recesses a part of the insulating resin substrate 30. In addition, the heat transfer member 20 is not limited to the above-mentioned structure in which it is fixed to the insulating resin substrate 30 via the adhesive layer 31, and may be configured to be embedded inside the opening 30a or the recessed portion.

[0098] On the front surface of the circuit board 3 , the plurality of light emitting elements 2 are arranged inside a region overlapping with the heat transfer member 20 in a plan view. That is, the plurality of light emitting elements 2 are arranged to face the heat transfer member 20 .

[0099] On the other hand, on the front surface of the circuit board 3, a plurality of electronic components 9 are arranged outside the region overlapping with the heat transfer member 20 when viewed from above, and inside the region overlapping with the insulating resin substrate 30 when viewed from above. That is, the plurality of electronic components 9 are arranged opposite to the insulating resin substrate 30.

[0100] In the present embodiment, the positions of the centers of the plurality of light emitting elements 2 coincide with the center position of the heat transfer member 20 in a plan view. In addition, the central axis of the heat sink 5 coincides with the central axis of the heat transfer member 20.

[0101] Thus, in the light source unit 1 of the present embodiment, the heat W1 generated by the light emitting element 2 can be efficiently transferred (dissipated) to the heat sink 5 side via the heat transfer member 20 .

[0102] In the light source unit 1 of the present embodiment, the light emitting element 2 is arranged on the heat transfer member 20 having high thermal conductivity, and the electronic component 9 is arranged on the insulating resin substrate 30 having low thermal conductivity, thereby suppressing the residual heat transferred from the electronic component 9 side to the light emitting element 2 side.

[0103] Furthermore, in the light source unit 1 of the present embodiment, it is possible to make it difficult for the heat W2 generated by the electronic component 9 to be transferred to the heat transfer member 20 side through the adhesive layer 31 .

[0104] Therefore, in the light source unit 1 of the present embodiment, it is possible to suppress the excess heat transferred from the electronic component 9 side to the light emitting element 2 side and prevent the temperature of the light emitting element 2 from rising.

[0105] In addition, the circuit board 3 has a first wiring pattern 12a, which is electrically connected to the light emitting element 2, among the plurality of wiring patterns 12 described above. At least a portion of the first wiring pattern 12a is located inside the region E overlapping with the heat transfer member 20 when viewed from above. That is, the first wiring pattern 12a is arranged so as to span between the heat transfer member 20 and the insulating resin substrate 30 when viewed from above.

[0106] Thus, in the light source unit 1 of the present embodiment, the heat W1 generated by the light emitting element 2 can be efficiently transferred (dissipated) from the first wiring pattern 12a to the heat sink 5 via the heat transfer member 20. In addition, the fixing strength between the heat transfer member 20 and the insulating resin substrate 30 can be increased by the first wiring pattern 12a.

[0107] Furthermore, the circuit board 3 includes, among the plurality of wiring patterns 12 , a second wiring pattern 12 b electrically connected to the electronic component 9 , and a connection pattern 12 c connecting the first wiring pattern 12 a and the second wiring pattern 12 b .

[0108] The second wiring pattern 12b is arranged outside the first wiring pattern 12a. The connection pattern 12c is formed between the first wiring pattern 12a and the second wiring pattern 12b to have a narrower width than the first wiring pattern 12a and the second wiring pattern 12b.

[0109] Thus, in the light source unit 1 of the present embodiment, it is possible to make it difficult for the heat W2 generated by the electronic component 9 to be transferred from the second wiring pattern 12b side to the first wiring pattern 12a side through the connection pattern 12c. Therefore, in the light source unit 1 of the present embodiment, it is possible to suppress the excess heat transferred from the electronic component 9 side to the light emitting element 2 side, and prevent the temperature of the light emitting element 2 from rising.

[0110] Furthermore, the circuit substrate 3 has a plurality of through holes 32 penetrating the insulating resin substrate 30 in the thickness direction, and a heat transfer pattern 12 d arranged on the other surface (rear surface) of the insulating resin substrate 30 .

[0111] The inner side of the hole portion penetrating the insulating resin substrate 30 in the thickness direction is plated with, for example, copper (Cu) or gold (Au), thereby forming a plurality of through holes 32. The plurality of through holes 32 are located inside the region overlapping with the second wiring pattern 12b when viewed from above, and are thus thermally connected to the second wiring pattern 12b.

[0112] The heat transfer pattern 12d is a full-surface wiring pattern (copper foil pattern in this embodiment) and is provided over the entire surface of the rear surface of the insulating resin substrate 30 (circuit substrate 3) except for the area where the wiring pattern for electrical connection is arranged. The heat transfer pattern 12d is thermally connected to the plurality of through holes 32.

[0113] In addition, since the heat transfer pattern 12d does not constitute a wiring pattern for electrical connection, it may be arranged on the surface of the heat transfer member 20. Thus, the heat transfer pattern 12d and the heat transfer member 20 can be thermally connected.

[0114] A protective layer 13 covering the heat transfer pattern 12d is provided on the rear surface of the insulating resin substrate 30 (circuit substrate 3). The protective layer 13 is provided in a region other than a region E overlapping with the heat transfer member 20 in a plan view.

[0115] Thus, in the light source unit 1 of the present embodiment, the heat W2 generated by the electronic component 9 can be transferred (dissipated) from the second wiring pattern 12b to the heat transfer pattern 12d via the plurality of through holes 32 and efficiently transferred (dissipated) to the heat sink 5 side.

[0116] In addition, in the light source unit 1 of the present embodiment, the thermal conductivity between the heat transfer member 20 and the heat transfer pattern 12d can be improved, and the heat W1 generated by the light emitting element 2 can be efficiently transferred (dissipated) to the heat sink 5 via the heat transfer member 20 and the heat transfer pattern 12d. Furthermore, the fixing strength between the heat transfer member 20 and the insulating resin substrate 30 can be improved by the heat transfer pattern 12d.

[0117] In addition, a relatively large number of through holes 32 are arranged on the side away from the light emitting element 2 on both sides of the position where the electronic component 9 is arranged. That is, a plurality of through holes 32 are arranged asymmetrically between the second wiring pattern 12b on the side where the light emitting element 2 is arranged and the second wiring pattern 12b on the opposite side across the electronic component 9, and the number of through holes 32 on the side where the light emitting element 2 is arranged is reduced.

[0118] Thus, in the light source unit 1 of the present embodiment, it is possible to make it difficult for the heat W2 generated by the electronic component 9 to be transferred to the side where the light emitting element 2 is located. Therefore, in the light source unit 1 of the present embodiment, it is possible to suppress the excess heat transferred from the electronic component 9 side to the light emitting element 2 side, and prevent the temperature of the light emitting element 2 from rising.

[0119] In addition, the electronic component 9 can also be configured to be arranged on the rear surface of the insulating resin substrate 30 (circuit substrate 3). In this case, the above-mentioned through hole 32 for heat transfer and heat transfer pattern 12d are omitted, and the second wiring pattern 12b is arranged on the rear surface of the insulating resin substrate 30 (circuit substrate 3), and the first wiring pattern 12a and the second wiring pattern 12b are electrically connected via the through hole 32.

[0120] As described above, in the light source unit 1 of the present embodiment, the heat W1 and W2 generated by the light emitting element 2 and the electronic component 9 can be efficiently dissipated to the outside via the heat sink 5 , thereby improving the heat dissipation performance.

[0121] Therefore, in the vehicle lamp 100 including the light source unit 1 of the present embodiment, even when applied to a high-intensity lamp such as the above-mentioned tail light and brake light, the light emission brightness of the light emitting element 2 can be maintained by high heat dissipation performance.

[0122] Furthermore, in the light source unit 1 of the present embodiment, at least a portion of the circuit substrate 3 relative to the light-emitting element 2 is formed by an insulating heat transfer component 20, thereby enabling the manufacturing cost to be kept low compared to a structure in which the entire circuit substrate 3 (insulating resin substrate 30) is formed of a heat transfer component 20 such as AlN.

[0123] In addition, the present invention is not necessarily limited to the contents of the above-mentioned embodiment, and various modifications can be added within the scope not departing from the gist of the present invention.

[0124] For example, in the above-mentioned embodiment, the case where the present invention is applied to the above-mentioned tail light and brake light is illustrated, but in the case of constituting a tail light and brake light, in addition to the above-mentioned light source unit 1, it can also be combined with other components such as an inner lens or an outer lens, a reflector, an extension, etc.

[0125] In addition, the vehicle lighting fixtures to which the present invention is applied are not limited to the above-mentioned taillights and brake lights. For example, the present invention can be widely applied to vehicle headlights (headlights), vehicle width lights (position lights), auxiliary headlights (sub-headlights), front (rear) fog lights (fog lamps), daytime running lights (DRL) lights, hood lights, taillights, brake lights (parking lights), reversing lights, direction indicators (turn signals) and other vehicle lighting fixtures.

[0126] In addition, in addition to the above-mentioned LED, light-emitting elements such as laser diodes (LD) can also be used for the light source unit to which the present invention is applied. In addition, the color of the light emitted by the light-emitting element is not limited to the above-mentioned red light, but can also be white light or orange light, etc., and can be appropriately changed according to the purpose of the light source unit. Furthermore, the number of light-emitting elements is not limited to multiple, but can also be 1. In addition, the configuration of the light-emitting element can also be appropriately changed.

Claims

1. A light source unit for a vehicle lamp, characterized in that: The vehicle lamp light source unit comprises: a circuit substrate provided with a light emitting element and a driving circuit for driving the light emitting element; and a heat sink that dissipates heat generated by the light emitting element to the outside via a substrate mounting portion on which the circuit substrate is mounted, At least a portion of the circuit substrate facing the light emitting element is formed of an insulating heat transfer member. The heat transfer member is made of a material having a higher thermal conductivity than the insulating resin substrate constituting the circuit substrate. The circuit substrate has a first wiring pattern arranged on one surface of the insulating resin substrate. At least a portion of the first wiring pattern is located inside a region overlapping the heat transfer component when viewed from above, the first wiring pattern is arranged so as to span between the heat transfer component and the insulating resin substrate when viewed from above, and is electrically connected to the light emitting element. The heat transfer member is arranged at a position where a portion of the insulating resin substrate is removed. The vehicle lamp light source unit includes a heat transfer pattern disposed on the other surface of the circuit substrate. The heat transfer pattern is provided over the entire surface of the other surface of the insulating resin substrate except for a region where a wiring pattern for electrical connection is provided, and is also provided on the surface of the heat transfer member. The circuit substrate has a second wiring pattern, the second wiring pattern being arranged on one surface of the insulating resin substrate and being electrically connected to an electronic component constituting the drive circuit. The circuit substrate has a plurality of through holes which are arranged to penetrate the insulating resin substrate and are thermally connected to the second wiring pattern. The heat transfer pattern is thermally connected to the plurality of through holes.

2. The vehicle lamp light source unit according to claim 1, wherein: The heat transfer component is made of aluminum nitride.

3. The vehicle lamp light source unit according to claim 1, wherein: The heat transfer member is arranged inside an opening that opens a portion of the insulating resin substrate. An insulating adhesive layer is provided between the heat transfer member and the opening.

4. The vehicle lamp light source unit according to claim 1, wherein: A protective layer covering the heat transfer pattern is provided on the other side of the circuit substrate. The protective layer is provided in a region other than a region overlapping with the heat transfer member in a plan view.

5. The vehicle lamp light source unit according to claim 1, wherein: The circuit substrate has a connection pattern, and the connection pattern connects the first wiring pattern and the second wiring pattern. The connection pattern is formed to have a narrower width than the first wiring pattern and the second wiring pattern.

6. The vehicle lamp light source unit according to claim 1, wherein: Between the side where the light emitting element is located and the side away from the light emitting element across the electronic components constituting the drive circuit, the plurality of through holes are relatively more arranged on the side away from the light emitting element.

7. The vehicle lamp light source unit according to claim 1, wherein: The light emitting element is arranged inside a region overlapping with the heat transfer member when viewed from above. The electronic components constituting the driving circuit are arranged outside a region overlapping the heat transfer member in a plan view.

8. The vehicle lamp light source unit according to claim 1, wherein: The circuit substrate is mounted on the substrate mounting portion via a thermally conductive adhesive.

9. The vehicle lamp light source unit according to claim 1, wherein: The heat sink has a plurality of fins protruding from a side opposite to the substrate mounting portion.

10. The vehicle lamp light source unit according to claim 1, wherein: The vehicle lamp light source unit includes a socket body provided with the heat sink and a connector portion, and the connector portion is electrically connected to the circuit board via a lead terminal.

11. A vehicle lamp, characterized in that: The vehicle lamp includes the vehicle lamp light source unit according to any one of claims 1 to 10.

12. The vehicle lamp according to claim 11, characterized in that: The vehicle lamp light source unit is detachably mounted on a lamp body.

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