阅读说明：本技术 光源单元以及车辆用灯具 (Light source unit and vehicle lamp ) 是由 铃木哲也 中川智之 于 2020-09-21 设计创作，主要内容包括：本发明涉及一种光源单元以及车辆用灯具,在不造成制造成本的高涨的情况下,降低在发光元件中产生的热对电子部件的影响,并且确保热从发光元件向散热板传递的高传递效率。该光源单元具备发光元件(29)、配置有发光元件的绝缘基板(28)、对发光元件进行供电的电路基板(27)以及设置有具有基板安装部(21)的散热板(13)的插座壳体(9),电路基板具有形成有电路图案(33)的树脂基座(30)和插通于树脂基座的金属块(31),在基板安装部上安装有电路基板,在金属块上安装有绝缘基板。(The invention relates to a light source unit and a vehicle lamp, which can reduce the influence of heat generated in a light-emitting element on electronic components and ensure high heat transfer efficiency from the light-emitting element to a heat dissipation plate without causing high manufacturing cost. The light source unit comprises a light emitting element (29), an insulating substrate (28) on which the light emitting element is arranged, a circuit substrate (27) for supplying power to the light emitting element, and a socket housing (9) provided with a heat sink (13) having a substrate mounting portion (21), wherein the circuit substrate comprises a resin base (30) on which a circuit pattern (33) is formed and a metal block (31) inserted into the resin base, the circuit substrate is mounted on the substrate mounting portion, and the insulating substrate is mounted on the metal block.)

1. A light source unit comprising a light emitting element, an insulating substrate on which the light emitting element is disposed, a circuit board for supplying power to the light emitting element, and a socket housing provided with a heat sink having a substrate mounting portion,

the circuit board has a resin base formed with a circuit pattern and a metal block inserted through the resin base,

the circuit board is mounted on the board mounting portion,

the insulating substrate is mounted on the metal block.

2. The light source unit according to claim 1,

an electrode portion is formed on the insulating substrate,

the electrode portion is connected to the circuit pattern through a metal wire.

3. The light source unit according to claim 1 or 2,

the shape of the insulating substrate is smaller than that of the metal block.

4. The light source unit according to claim 1 or 2,

the insulating substrate is bonded to the metal block by a thermally conductive adhesive.

5. A vehicle lamp having a light source unit, characterized in that,

the light source unit includes:

a socket housing provided with a heat dissipation plate having a substrate mounting portion and having heat dissipation fins;

a circuit board having a resin base formed with a through-hole and a metal block disposed in the hole, the resin base having a circuit pattern formed thereon and being mounted on the board mounting portion;

an insulating substrate on which an electrode portion connected to the circuit pattern is formed and which is mounted on the metal block; and

and a light-emitting element mounted on the insulating substrate.

Technical Field

The present invention relates to a light source unit and a vehicle lamp having a socket housing for mounting a circuit board and emitting light from a light emitting element.

Background

In a vehicle lamp, for example, a light source unit is provided that is detachable from a lamp housing including a lamp housing and a cover, and a light emitting element such as a light emitting diode is used as a light source of the light source unit.

In such a light source unit, a heat sink plate formed of a metal material and having a board mounting portion is provided in a socket housing, and a circuit board is mounted on the board mounting portion (see, for example, patent document 1).

The circuit board is provided with a light emitting element, and heat generated when the light emitting element emits light is transferred to the heat sink, so that temperature rise of the light emitting element is suppressed, and a good light emitting state of the light emitting element can be ensured.

As described above, in the light source unit, it is necessary to secure a good light emission state of the light emitting element by suppressing the temperature rise of the light emitting element, and therefore it is preferable to secure high transfer efficiency of heat from the light emitting element to the heat sink.

In order to ensure high heat transfer efficiency from the light emitting element to the heat sink, the light source unit includes a circuit board made of, for example, a ceramic substrate. Since the ceramic substrate has high thermal conductivity relative to the resin substrate, high heat transfer efficiency can be ensured in which heat is transferred from the light-emitting element to the heat sink via the circuit substrate.

However, when a ceramic substrate is used as a circuit board, since the circuit board has high thermal conductivity, heat generated in the light-emitting element is also easily transmitted to an electronic component mounted on the circuit board, and there is a possibility that the bonding state of the electronic component to the circuit board is affected or the characteristics of the electronic component are affected.

Therefore, there are cases in the light source unit: for example, a resin substrate is used as the circuit substrate, and a heat conduction through hole (through hole) is formed in a portion of the resin substrate where the light emitting element is mounted. By using the resin substrate as the circuit substrate, heat generated in the light emitting element is hardly transferred to the electronic component, and on the other hand, heat generated in the light emitting element is transferred to the heat sink via the heat conductive through hole, so that high transfer efficiency of heat transfer from the light emitting element to the heat sink can be ensured while reducing an influence on the electronic component opposing the circuit substrate.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-113234

Disclosure of Invention

Problems to be solved by the invention

However, in the light source unit in which the heat conductive through holes are formed in the portion of the resin substrate on which the light emitting element is mounted, a plurality of heat conductive through holes need to be formed to secure necessary heat dissipation performance, a large heat conductive through hole formation area is required, and the circuit substrate may be increased in size. In this case, such a configuration can be adopted if there is no limitation in the size of the circuit board, but if there is a limitation in the size of the circuit board, it may be difficult to mount necessary electronic components on the circuit board.

In addition, each time the heat conductive through hole is formed, a corresponding processing work and processing time are required, which causes a problem of high manufacturing cost.

Therefore, an object of the light source unit and the vehicle lamp according to the present invention is to reduce the influence of heat generated in the light emitting element on the electronic component and to ensure high heat transfer efficiency from the light emitting element to the heat sink without causing an increase in manufacturing cost.

Means for solving the problems

A light source unit according to a first aspect of the present invention is a light source unit including a light emitting element, an insulating substrate on which the light emitting element is disposed, a circuit board for supplying power to the light emitting element, and a socket case provided with a heat sink having a board mounting portion, wherein the circuit board includes a resin base on which a circuit pattern is formed and a metal block inserted into the resin base, the circuit board is mounted on the board mounting portion, and the insulating substrate is mounted on the metal block.

Thus, a circuit board is mounted on the board mounting portion of the heat sink, and an insulating board on which a light-emitting element is mounted on the metal block of the circuit board.

Second, in the light source unit according to the present invention, it is preferable that an electrode portion is formed on the insulating substrate, and the electrode portion is connected to the circuit pattern by a metal wire.

Thus, the electrode portion is connected to the circuit pattern via the metal wire in a state where the insulating substrate is mounted on the metal block.

Third, in the light source unit according to the present invention, it is preferable that the insulating substrate has an outer shape smaller than an outer shape of the metal block.

In this way, the entire insulating substrate can be mounted on the metal block, and therefore, heat generated in the light-emitting element is efficiently transferred to the metal block and further transferred from the metal block to the heat sink.

Fourth, in the light source unit according to the present invention, it is preferable that the insulating substrate is bonded to the metal block with a thermally conductive adhesive.

Thus, the insulating substrate is bonded to the metal block with a material having high thermal conductivity.

A fifth aspect of the present invention is a vehicle lamp including a light source unit, the light source unit including a light emitting element, an insulating substrate on which the light emitting element is disposed, a circuit board for supplying power to the light emitting element, and a socket housing provided with a heat dissipating plate having a substrate mounting portion, the circuit board including a resin base on which a circuit pattern is formed and a metal block inserted into the resin base, the circuit board being mounted on the substrate mounting portion, and the insulating substrate being mounted on the metal block.

In this way, in the light source unit, the circuit board is mounted on the board mounting portion of the heat sink, and the insulating board on which the light emitting element is mounted on the metal block of the circuit board.

Effects of the invention

According to the present invention, since the circuit board is mounted on the board mounting portion of the heat sink and the insulating board on which the light-emitting element is mounted on the metal block of the circuit board, it is possible to reduce the influence of heat generated in the light-emitting element on the electronic component without causing an increase in manufacturing cost and to ensure high heat transfer efficiency in transferring heat from the light-emitting element to the heat sink.

Drawings

Fig. 1 is a view showing an embodiment of the present invention together with fig. 2 to 9, and this view is a sectional view of a vehicle lamp.

Fig. 2 is a perspective view of the light source unit.

Fig. 3 is a sectional view of the light source unit.

Fig. 4 is a rear view of the light source unit.

Fig. 5 is a perspective view showing a state where an insulating substrate is mounted on a circuit board.

Fig. 6 is a cross-sectional view showing a state where an insulating substrate is mounted on a circuit board.

Fig. 7 is a cross-sectional view showing an example in which the front surface of the insulating substrate is positioned on the front side of the front surface of the circuit substrate.

Fig. 8 is a cross-sectional view showing an example in which the front surface of the insulating substrate is located on the rear side of the front surface of the circuit substrate.

Fig. 9 is a perspective view showing an example in which the electrode portion is connected to the connection terminal portion without using a metal wire.

Description of the reference numerals

1: a vehicular lamp; 8: a light source unit; 9: a socket housing; 13: a heat dissipation plate; 16: a first heat sink; 17: a second heat sink; 21: a substrate mounting portion; 27: a circuit substrate; 28: an insulating substrate; 29: a light emitting element; 30: a resin base; 31: a metal block; 32: a placement hole; 33: a circuit pattern; 35 a: an electrode section; 36: a metal wire.

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the following description, the front-back, up-down, left-right directions are indicated with the optical axis direction of light emitted from the light source unit being the front-back direction and the light emission direction being the front. The front, rear, upper, lower, left, and right directions shown below are for convenience of description, and the practice of the present invention is not limited to these directions.

The vehicle lamp 1 includes a lamp housing 2 having a recess opened at the front, and a cover 3 (see fig. 1) closing an opening 2a at the front of the lamp housing 2. The lamp housing 2 and the cover 3 constitute a lamp housing 4, and an internal space of the lamp housing 4 forms a lamp chamber 5.

The rear end portion of the lamp housing 2 is provided as a substantially cylindrical unit mounting portion 6 penetrating in the front-rear direction, and a space inside the unit mounting portion 6 is formed as a mounting hole 6 a. Engaging projections 7, … … projecting inward are provided on the inner peripheral surface of the unit mounting portion 6 so as to be separated in the circumferential direction.

A light source unit 8 is detachably mounted on the unit mounting portion 6 of the lamp housing 2. The light source unit 8 has a socket housing 9, a power supply body 10, and a light emitting module 11 (see fig. 2 to 4).

The socket housing 9 is integrally formed with a resin molding portion 12 and a heat dissipation plate 13 by insert molding or the like.

The resin molded portion 12 is formed by containing a conductive material such as carbon in a resin material, and has high thermal conductivity. The resin molding part 12 has a substantially disk-shaped base surface part 14 facing the front-rear direction, a projecting part 15 projecting forward from the central part of the base surface part 14, first fins 16, … … projecting rearward from the base surface part 14, second fins 17, 17 projecting rearward from the base surface part 14, and a connector coupling part 18 projecting rearward from the base surface part 14.

The projecting portion 15 has a substrate arrangement portion 19 whose outer shape is formed in a circular shape, and engagement portions 20, 20 projecting outward from a distal end portion of the substrate arrangement portion 19.

The substrate arrangement portion 19 is formed with an arrangement recess 19a opened at the front. The arrangement recess 19a is formed in a substantially rectangular shape and is larger than the outer shape of the light emitting module 11. The engaging portions 20, 20 are provided separately in the circumferential direction.

The first fins 16, … … are arranged at equal intervals in the left-right direction, for example.

The second fins 17, 17 are located on both sides of the first fins 16, … …, and protrude from the base face 14 in the same orientation as the first fins 16, … ….

The connector coupling portion 18 is formed in a tubular shape having an axial direction in the front-rear direction, and is provided at a position surrounded by the first fins 16, … … and the second fins 17, 17. A connector not shown is connected to the connector coupling portion 18.

The heat sink 13 is formed in a predetermined shape from a metal material having high thermal conductivity. The heat sink 13 includes a substrate mounting portion 21, first connecting portions 22 and 22, second connecting portions 23 and 23, and heat dissipating portions 24 and 24.

The board mounting portion 21 and the second connecting portions 23 and 23 are formed in a plate shape facing in the front-rear direction, and the first connecting portions 22 and the heat dissipating portions 24 and 24 are formed in a plate shape facing in the left-right direction. The front surface of the board mounting portion 21 is formed as a mounting surface 21 a.

The front end portions of the first coupling portions 22, 22 are continuous with both left and right end portions of the substrate mounting portion 21, the inner end portions of the second coupling portions 23, 23 in the left-right direction are continuous with the rear end portions of the first coupling portions 22, respectively, and the front end portions of the heat dissipation portions 24, 24 are continuous with the outer end portions of the second coupling portions 23, 23 in the left-right direction.

The heat sink 13 is in a state where the mounting surface 21a of the board mounting portion 21 is exposed forward in the arrangement recess 19a of the board arrangement portion 19. The first connecting portions 22, 22 of the heat sink 13 are positioned inside the substrate arrangement portion 19, the second connecting portions 23, 23 are positioned inside the base surface portion 14, and the heat dissipation portions 24, 24 are positioned inside the second heat dissipation fins 17, respectively.

An insertion hole, not shown, is formed in the resin molding portion 12 at a position from the substrate arrangement portion 19 to the base surface portion 14, and the insertion hole communicates with the arrangement recess 19a and the inside of the connector coupling portion 18.

The power feeding unit 10 includes a terminal holding portion 25 made of an insulating resin material, and connection terminals 26, and 26 held by the terminal holding portion 25 and connected to a power supply circuit (external power) not shown.

The terminal holding portion 25 is formed in a flat shape extending in the front-rear direction. The connection terminals 26, 26 are made of a metal material, and in a state of being arranged in the left-right direction, both front and rear end portions protrude forward and backward from the terminal holding portion 25, respectively, and portions other than the front and rear end portions are located inside the terminal holding portion 25.

The terminal holding portion 25 and the connection terminals 26, 26 of the power feeding body 10 are integrally formed by, for example, insert molding. The power feeding body 10 is inserted into the insertion hole formed in the resin molding portion 12 except for the front and rear end portions of the connection terminals 26, 26.

The light-emitting module 11 includes a circuit board 27 formed in a substantially rectangular shape facing the front-rear direction, an insulating board 28 mounted on the circuit board 27, and light-emitting elements 29, and … … (see fig. 2 and 5) mounted on the insulating board 28.

The circuit board 27 is formed in a substantially rectangular shape, and includes a resin base 30 and a metal block 31.

The resin base 30 is formed in a substantially rectangular shape and made of a resin material such as a glass epoxy material. A circular through-hole 32 is formed in the center of the resin base 30. A circuit pattern 33 is formed on the front surface of the resin base 30, and predetermined electronic components (control elements) 34, … … are joined to and mounted on the circuit pattern 33. A part of the circuit pattern 33 is formed as connection terminal portions 33a, 33 a.

As the metal block 31, for example, copper is used, and the metal block 31 is disposed in a state of being fitted into the disposition hole 32 and inserted through the resin base 30. The metal block 31 is formed in a disc shape, and a front surface 31a is located on the same plane as the front surface 30a of the resin base 30, for example, and a rear surface 31b is located on the same plane as the rear surface 30b of the resin base 30, for example (see fig. 6).

The circuit board 27 is mounted on the mounting surface 21a of the board mounting portion 21 of the heat sink 13 by, for example, a thermally conductive and electrically nonconductive adhesive or adhesive sheet (see fig. 2 and 3). In a state where the circuit board 27 is mounted on the board mounting portion 21, the metal block 31 is in surface contact with the mounting surface 21a via an adhesive or an adhesive sheet, and the tip portions of the connection terminals 26, 26 are inserted through the resin base 30 and connected to the circuit pattern 33 by solder or the like.

The connection terminals 26, and 26 may have distal end portions located on the outer peripheral side of the circuit board 27 and connected to the circuit pattern 33 by conductive leads or the like.

The insulating substrate 28 is formed in a rectangular shape, for example, and the outer shape is smaller than the outer shape of the metal block 31. The insulating substrate 28 is made of aluminum nitride (aln) or aluminum oxide (alumina). Aluminum nitride and aluminum oxide are non-conductive, but have high thermal conductivity. A connection pattern 35 is formed on the front surface of the insulating substrate 28, and a part of the connection pattern 35 is formed as electrode portions 35a, 35 a.

As the Light Emitting elements 29, and … …, for example, LEDs (Light Emitting diodes) are used. The light emitting elements 29, … … are bonded to the connection pattern 35, for example, connected in series.

The light emitting elements 29, and … … may be connected in series by the connection pattern 35, or the connection patterns 35 and 35 may be formed in units of the light emitting elements 29, and … … … …, and the light emitting elements 29, and … … may be connected in series by a wire or the like in a state where the light emitting elements 29, and … … are bonded to the connection patterns 35, and … …, respectively.

The insulating substrate 28 on which the light-emitting elements 29, and … … are mounted is mounted on the metal block 31 of the circuit board 27. The insulating substrate 28 is attached to the metal block 31, for example, at a position inside the outer periphery of the metal block 31 by being bonded with a thermally conductive adhesive containing a filler having high thermal conductivity, such as a metal filler or an inorganic filler, in an adhesive (base agent).

In a state where the insulating substrate 28 is mounted on the metal block 31, the electrode portions 35a, 35a of the connection pattern 35 are connected to the connection terminal portions 33a, 33a of the circuit pattern 33 via metal lines 36, 36 made of, for example, aluminum, gold, or the like, respectively. By connecting the electrode portions 35a, 35a to the connection terminal portions 33a, the light-emitting elements 29, … … are connected to the connection terminals 26, … … via the connection pattern 35, the metal wires 36, and the circuit pattern 33 (see fig. 5), and thus power from the power supply circuit can be supplied to the light-emitting elements 29, … …. In general, the connection by the metal wires 36 and 36 is performed first as a first bonding side to connect the electrode portions 35a and 35a of the insulating substrate 28, and then as a second bonding side to connect the connection terminal portions 33a and 33a of the circuit substrate 27. However, in this case, since there is a possibility that the wires 36 and 36 shield part of the light emitted from the light emitting elements 29, and … …, the bonding procedure may be performed in the reverse order to the above procedure. In addition, in order to protect the metal wires 36, the metal wires 36, 36 may be protected by a protective resin.

A frame 37 (see fig. 2 and 3) is mounted on the circuit board 27 between the light emitting elements 29 and the electronic components 34 and 34. The frame 37 is formed in a substantially annular shape and is disposed at a position surrounding the light emitting elements 29, 29.

The inside of the frame 37 is filled with a phosphor not shown, and the light emitting elements 29 and 29 are sealed with the phosphor.

The lens portion 38 is disposed on the phosphor. The lens portion 38 is formed of a transparent resin material in a hemispherical shape protruding forward. In addition, although the light emitting elements 29, and … … are sealed by the lens portion 38 in the present embodiment, the light emitting elements may have other configurations depending on optical characteristics required for use, for example, the frame 37 and the lens portion 38 may not be provided. Further, if there is a light emitting element that emits light of a desired emission color, the inside of the housing 37 may not be filled with a phosphor.

In the light source unit 8 configured as described above, an annular gasket 39 (see fig. 1) is fitted to the outside of the projecting portion 15. The gasket 39 is formed of a resin material or a rubber material.

In a state where the washer 39 is attached to the light source unit 8, the projecting portion 15 is inserted into the unit mounting portion 6 of the lamp housing 2 from the rear side, and rotates in the circumferential direction, and the engaging portions 20, 20 engage with the engaging projections 7, … … from the rear side, respectively. At this time, the engaging projections 7, … … are sandwiched by the engaging portions 20, 20 and the washer 39, and the light source unit 8 is attached to the lamp housing 2. In a state where the light source unit 8 is attached to the lamp housing 2, the unit attachment portion 6 is closed by the gasket 39, and foreign matter such as moisture from the outside is prevented from entering the lamp chamber 5 through the unit attachment portion 6.

Conversely, when the light source unit 8 is rotated in the circumferential direction in the direction opposite to the above, the engagement of the engaging portions 20, 20 with the engaging protrusions 7, … … is released, and the protruding portion 15 is pulled out from the unit mounting portion 6, whereby the light source unit 8 can be detached from the lamp housing 2.

When power is supplied from the power supply circuit to the light emitting elements 29, and … … through the connection terminals 26, and 26 in a state where the light source unit 8 is mounted on the lamp housing 2, light is emitted from the light emitting elements 29, and … …. The light emitted from the light emitting elements 29, and … … passes through the fluorescent material and the lens portion 38, and is radiated to the outside through the cover 3. At this time, the lens unit 38 controls the irradiation direction of light so that the light is irradiated to the outside in a predetermined direction.

When the light emitting elements 29, and … … emit light, heat is generated in the light emitting elements 29, and … …, and the generated heat is transmitted from the insulating substrate 28 to the metal block 31 of the circuit board 27, and is transmitted from the metal block 31 to the heat sink 13. The heat generated in the light emitting elements 29, and … … transferred to the heat sink 13 is mainly transferred from the heat dissipation portions 24 and 24 of the heat sink 13 to the resin molded portion 12 containing a material having thermal conductivity such as carbon, and is released from the first heat radiation fins 16, and … … and the second heat radiation fins 17 and 17.

Therefore, temperature rise of the light-emitting elements 29, and … … can be suppressed, and favorable light-emitting states of the light-emitting elements 29, and … … can be ensured.

As described above, in the vehicle lamp 1 and the light source unit 8, the circuit board 27 includes the resin base 30 on which the circuit pattern 33 is formed and the metal block 31 inserted into the resin base 30, the circuit board 27 is mounted on the board mounting portion 21, and the insulating board 28 is mounted on the metal block 31.

Therefore, since the circuit board 27 is mounted on the board mounting portion 21 of the heat sink 13 and the insulating board 28 on which the light emitting elements 29, and … … are mounted is mounted on the metal block 31 of the circuit board 27, it is not necessary to form a plurality of heat conducting through holes in the circuit board 27, and heat generated in the light emitting elements 29, and … … is less likely to be transmitted to the electronic components 34, and … … mounted on the resin base 30. Accordingly, without causing an increase in manufacturing cost, it is possible to reduce the influence of heat generated in the light emitting elements 29, and … … on the electronic component 34, and to ensure high heat transfer efficiency from the light emitting elements 29, and … … to the heat sink 13.

Further, although copper is used as the metal block 31, for example, copper has a thermal conductivity about 20 times that of ceramic, and therefore, by using copper as the metal block 31, it is possible to ensure extremely high transfer efficiency of heat from the light emitting elements 29, … … to the heat sink 13.

Further, since the electrode portions 35a and 35a are connected to the circuit pattern 33 via the metal lines 36 and 36, the electrode portions 35a and 35a are connected to the circuit pattern 33 via the metal lines 36 and 36 in a state where the insulating substrate 28 is mounted on the metal block 31, and thus the electrode portions 35a and 35a can be reliably connected to the circuit pattern 33 with a simple configuration, and the reliability of the operation of the light emitting elements 29, and … … can be improved.

Further, in the light source unit 8, the outer shape of the insulating substrate 28 is smaller than the outer shape of the metal block 31.

Therefore, since the entire insulating substrate 28 can be mounted on the metal block 31, the heat generated in the light emitting elements 29, and … … is efficiently transferred to the metal block 31 and from the metal block 31 to the heat sink 13, and therefore, the temperature rise of the light emitting elements 29, and … … is effectively suppressed, and a stable lighting state of the light emitting elements 29, and … … can be ensured.

Further, since the insulating substrate 28 is bonded to the metal block 31 by the heat conductive adhesive and the insulating substrate 28 is bonded to the metal block 31 by the material having high heat conductivity, the efficiency of transferring heat generated in the light emitting elements 29, and … … to the metal block 31 is increased, and a more stable lighting state of the light emitting elements 29, and … … can be ensured.

In the above, the example is shown in which the front surface 31a of the metal block 31 is located on the same plane as the front surface 30a of the resin base 30, but the front surface 31a of the metal block 31 may be located on the front side of the front surface 30a of the resin base 30 (see fig. 7).

Since the front surface 31a of the metal block 31 is positioned on the front side of the front surface 30a of the resin base 30 in this manner, the light emitting elements 29, and … … are easily positioned forward relative to the electronic component 34, and therefore, the light emitted from the light emitting elements 29, and … … is not shielded by the electronic component 34, and the utilization efficiency of the light emitted from the light emitting elements 29, and … … can be improved.

However, even when the front surface 31a of the metal block 31 is positioned on the same plane as the front surface 30a of the resin base 30, the front surface of the insulating substrate 28, which is the mounting surface of the light-emitting elements 29, and … …, is positioned closer to the thickness of the insulating substrate 28 than the front surface 30a of the resin base 30, which is the mounting surface of the electronic component 34 (see fig. 6). Therefore, in this case, since the light emitting elements 29, and … … are easily positioned forward relative to the electronic component 34, the light emitted from the light emitting elements 29, and … … is less likely to be shielded by the electronic component 34, and the utilization efficiency of the light emitted from the light emitting elements 29, and … … can be improved.

On the other hand, the front surface 31a of the metal block 31 may be located behind the front surface 30a of the resin base 30 (see fig. 8).

In the light source unit 8, the control member 40 such as a condenser lens for controlling the light emitted from the light emitting elements 29, and … … or a reflector for reflecting the light may be disposed in front of the light emitting elements 29, and … …, but in such a case, the control member 40 can be brought closer to the circuit board 27 by positioning the front surface 31a of the metal block 31 rearward of the front surface 30a of the resin base 30.

Therefore, by adopting the structure in which the front surface 31a of the metal block 31 is positioned on the rear side of the front surface 30a of the resin base 30, the light source unit 8 can be downsized in the structure in which the control member 40 is disposed.

In the above, the examples were described in which the electrode portions 35a, 35a of the connection pattern 35 were connected to the connection terminal portions 33a, 33a of the circuit pattern 33 by the metal wires 36, respectively, but the electrode portions 35a, 35a may be connected to the connection terminal portions 33a, 33a without using the metal wires 36, 36 (see fig. 9). In fig. 9, three light-emitting elements 29, and 29 are provided for easy understanding.

In this case, for example, the electrode portions 35a and 35a of the connection pattern 35 are formed to extend from the side surface to the rear surface of the insulating substrate 28, the insulating substrate 28 is formed to have a size such that a part thereof is positioned on the outer peripheral side of the metal block 31, and the electrode portions 35a and 35a are positioned on the outer peripheral side of the metal block 31. The electrode portions 35a, 35a are connected by portions formed on the rear surface and the side surfaces of the insulating substrate 28 coming into contact with the connection terminal portions 33a, 33a formed on the resin base 30 of the circuit board 27.

In this way, by adopting the structure in which the electrode portions 35a, 35a are formed to extend from the side surfaces to the rear surface of the insulating substrate 28 and to be in contact with the connection terminal portions 33a, the electrode portions 35a, 35a are connected to the connection terminal portions 33a, 33a without using the metal wires 36, and therefore, the number of components can be reduced and workability in the connection work can be improved.

In this case, the electrode portions 35a and 35a may be joined to the connection terminal portions 33a and 33a using solder or a conductive adhesive.