Vehicle lighting fixtures

Abstract

To provide a vehicular lamp fitting which can prevent a bonding wire from shielding emitted light from a light emitting surface while improving heat radiation performance from a light emitting part.SOLUTION: A vehicular lamp fitting 1 includes: a light emitting part 31 having light emitting elements; a circuit board 32; and a heat sink 4. In the vehicular lamp fitting, a front area of the heat sink 4 is divided into a first area 41 and a second area 42. The light emitting part 31 is fixed to the first area 41 and the circuit board 32 is fixed to the second area 42. Each light emitting part side terminal 31b provided at the light emitting part 31 and each substrate side terminal 32d provided at the circuit board 32 are electrically connected by a bonding wire 33. The light emitting part side terminal 31b is located between a light emitting surface 31e which covers the light emitting elements in a front view and the substrate side terminal 32d.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a vehicle lamp. [Background technology]

[0002] Conventionally, a semiconductor optical module is known in which a semiconductor light source is mounted on a disk-shaped module having a conductive surface, the module having good thermal conductivity, and a control electronic device is integrated therein, the control electronic device being arranged around the semiconductor light source and consisting of a circuit board having at least two conductor track surfaces, a first conductor track surface facing outward in the radiation direction of light in an assembled state, and a second conductor track surface being surrounded by a closed cavity provided in the module (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2010-524210 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional semiconductor optical modules, the semiconductor light source and the circuit board are electrically connected, but the specific method of connection is not disclosed. Therefore, when the semiconductor light source and the circuit board are electrically connected by a bonding wire, there is a risk that the bonding wire, which is set by joining to two separate terminals, may block the light emitted from the light emitting surface of the light source.

[0005] The present disclosure has been made in light of the above-mentioned problems, and has an object to provide a vehicle lamp that can prevent a bonding wire from blocking light emitted from a light-emitting surface. [Means for solving the problem]

[0006] In order to achieve the above object, the vehicle lamp of the present disclosure includes a light-emitting section having a light-emitting element, a circuit board, and a heat sink. In this vehicle lamp, the front area of ​​the heat sink is divided into a first area and a second area, the light-emitting section is fixed to the first area, and the circuit board is fixed to the second area. A light-emitting section side terminal provided on the light-emitting section and a board side terminal provided on the circuit board are electrically connected by a pair of bonding wires. The light-emitting section side terminal is disposed between the light-emitting surface covering the light-emitting element and the board side terminal when viewed from the front. The circuit board has a peripheral unit component arranged at an inner position where the pair of bonding wires are close to each other, and a peripheral unit component arranged at an outer position where the pair of bonding wires are separated from each other. The bonding range is the allowable angle range when viewed from the front for setting the bonding wire, and is defined by the minimum angle line and maximum angle line passing through the joint center position of the light-emitting side terminal. The minimum angle line of the bonding range is defined by a first parallel line that is parallel to the vertical line passing through the center position of the light-emitting surface. The maximum angle line of the bonding range is set by a second parallel line parallel to the horizontal line passing through the center position of the light emitting surface. The angle of the bonding wire as viewed from the front is set to an angle included in the bonding range and in an intermediate angle range between the minimum angle line and the maximum angle line. Effect of the Invention

[0007] Therefore, it is possible to prevent the bonding wires from blocking the light emitted from the light emitting surface while improving the heat dissipation performance from the light emitting portion. In addition to being able to reliably prevent interference between the pair of bonding wires and the peripheral unit components, the joining operation by the wire bonding technique can be carried out smoothly without any hindrance. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram illustrating a vehicle lamp according to the present disclosure. [Diagram 2] FIG. 2 is a front perspective view showing a light source unit according to the present disclosure. [Diagram 3] FIG. 2 is an exploded front perspective view showing a light source unit according to the present disclosure. [Figure 4] 1 is an exploded rear perspective view showing a heat sink / light source side connector of a light source unit of the present disclosure. [Diagram 5] 1 is a front view showing a light emitting portion, a circuit board, and a heat sink included in a light source unit of the present disclosure. [Figure 6] 6 is a cross-sectional view taken along line II in FIG. 5, showing the light-emitting section, the circuit board, and the heat sink included in the light source unit of the present disclosure. [Figure 7] 1 is a front view of a light-emitting portion illustrating a bonding range, which is an allowable angle range when viewed from the front, for setting a bonding wire according to the present disclosure. [Figure 8] 7 is an enlarged cross-sectional view of part B in FIG. 6 for explaining the height relationship in side view between the light-emitting unit side terminal, the board side terminal, and the light-emitting surface according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vehicle lamp according to an embodiment of the present disclosure will be described with reference to a first embodiment shown in the drawings. EXAMPLES

[0010] The vehicle lamp 1 in the first embodiment is used as a lamp for a vehicle such as an automobile, and is applied to, for example, a head lamp, a fog lamp, a daytime running lamp, a clearance lamp, a rear lamp, and the like. In the following description, in the vehicle lamp 1, the direction in which light is emitted in the traveling direction (front-rear direction) when the vehicle is traveling straight is the optical axis direction (referred to as "Z" in the drawings, and the side to be emitted is the front side), the vertical direction in a state in which the vehicle lamp is mounted on the vehicle is the up-down direction (referred to as "Y" in the drawings), and the direction perpendicular to the optical axis direction and the up-down direction (left-right direction) is the width direction (referred to as "X" in the drawings). Hereinafter, the configuration of the first embodiment will be described by dividing it into "overall configuration", "light source unit configuration", and "main part configuration".

[0011] The overall configuration will be described with reference to Fig. 1. The vehicle lamp 1 includes a lamp housing 11, a lamp lens 12, a reflector 13, and a light source unit 2, as shown in Fig. 1.

[0012] The lamp housing 11 is made of a light-impermeable material such as a colored or painted resin material, and has a hollow shape with an open front and closed rear. The lamp housing 11 is provided with a mounting hole 11a that penetrates the closed rear end. A plurality of notches and stoppers are provided at approximately equal intervals on the edge of the mounting hole 11a.

[0013] The lamp lens 12 is made of a light-transmitting material such as a transparent resin material or a glass material, and is formed into a shape capable of covering the open front end of the lamp housing 11. The lamp lens 12 is fixed in a sealed state to the opening of the lamp housing 11, ensuring watertightness. A lamp chamber 14 is formed by being partitioned into the lamp housing 11 and the lamp lens 12.

[0014] The reflector 13 is a light distribution control unit that controls the distribution of light emitted from the light source unit 2, and is fixed to the lamp housing 11 or the like. The reflector 13 is disposed in the lamp chamber 14. The reflector 13 is formed in a curved shape having a focal point near the light emitting portion 31 (described later) of the light source unit 2. The reflector 13 has a reflective surface 13a on its inner surface that reflects light, and a mounting hole 13b is provided at its bottom. The mounting hole 13b is in a positional relationship that communicates with the mounting hole 11a of the lamp housing 11 when the reflector 13 is disposed in the lamp chamber 14. Note that the reflector 13 is formed as a separate member from the lamp housing 11, but may be an integral configuration, i.e., the inner surface of the lamp housing 11 may be the reflective surface, or may have another configuration. Also, instead of the reflector 13 (reflective surface 13a), a light guide member may be provided on the front side in the optical axis direction of the light source unit 2 to emit light at a position or in a region of a different size from that of the light emitting portion 31, and is not limited to the configuration of Example 1. Even when a light guide member is provided in this way, the vehicle lamp 1 can be used as, for example, a headlamp, a fog lamp, a daytime running lamp, or a clearance lamp.

[0015] The light source unit 2 is disposed in the lamp chamber 14, passing through a mounting hole 11a of the lamp housing 11 and a mounting hole 13b of the reflector 13. The light source unit 2 is detachably attached to the mounting hole 11a of the lamp housing 11 with a sealing member 15 (O-ring, rubber packing) interposed between the light source unit 2 and the lamp housing 11. The light source unit 2 may be provided in the lamp chamber 14 via an optical axis adjustment mechanism for the up-down direction or an optical axis adjustment mechanism for the left-right direction.

[0016] The socket 7 of the light source unit 2 is provided with a power supply connector 6 to which a harness 16 is connected. The socket body 71 of the socket 7 has a peripheral wall 71a, a flange wall 71b, and an attachment protrusion 71d.

[0017] Next, the configuration of the light source unit 2 will be described with reference to Fig. 2 to Fig. 4. The light source unit 2 is a socket-type module in which a light source 3, a heat sink 4, a light source side connector 5, a power supply side connector 6, and a socket 7 are compactly integrated together (see Figs. 1 and 3).

[0018] As shown in FIGS. 2 and 3, the light source 3 includes a light emitting portion 31, a circuit board 32, and a pair of bonding wires 33.

[0019] The light emitting unit 31 emits light by applying a drive voltage from the circuit board 32 to the light emitting element, and is directly fixed to the center of the front area of ​​the heat sink 4 when the front surface of the heat sink 4 is viewed from the optical axis direction. The light emitting unit 31 includes a submount substrate 31a, a pair of light emitting unit side terminals 31b, a light emitting chip 31c, a heat conductive adhesive layer 31d, and a light emitting surface 31e. The detailed configuration of the light emitting unit 31 will be described later.

[0020] The circuit board 32 generates a drive voltage to be applied to the light emitting unit 31 based on a control command from a lamp control circuit (not shown) mounted on the vehicle, and is directly fixed to a front area of ​​the heat sink 4 in the optical axis direction, excluding the fixing area of ​​the light emitting unit 31. The circuit board 32 is provided with a semiconductor element drive circuit having a capacitor 32f and the like. In addition, the circuit board 32 is provided with a pair of crimping holes 32a, a pair of curved holes 32b, a pair of terminal connection holes 32c, a pair of board side terminals 32d, and an adhesive sheet 32e. The detailed configuration of the circuit board 32 will be described later.

[0021] The bonding wire 33 is a conductive wire made of an electrically conducting metal, and both ends of the wire are bonded to the light-emitting unit side terminal 31b and the board side terminal 32d by a wire bonding method using ultrasonic vibration. The detailed configuration of the bonding wire 33 will be described later.

[0022] The heat sink 4 is a heat dissipation member that transfers heat generated by the light emitting unit 31 to the socket 7, and is made of aluminum die casting with high thermal conductivity. As shown in Figures 3 and 4, the heat sink 4 integrally includes a first region 41, a second region 42, a fin portion 43, and a pair of positioning protrusions 46. The heat sink 4 may be made of another metal material with high thermal conductivity, or a resin material with high thermal conductivity.

[0023] The first region 41 is a surface to which the light emitting unit 31 is directly fixed, and is formed in an upper region of the front region when the front region of the heat sink 4 is divided into two regions as shown in Fig. 3. The first region 41 is a flat surface that is higher and protrudes in the optical axis direction than the second region 42. The detailed configuration of the first region 41 will be described later.

[0024] The second region 42 is a surface to which the circuit board 32 is directly fixed, and is formed in a lower region of the front region when the front region of the heat sink 4 is divided into two regions as shown in FIG. 3. The second region 42 is a flat surface having a lower height in the optical axis direction than the first region 41. A pair of terminal insertion holes 42a are provided penetrating the second region 42 in the optical axis direction. Furthermore, as shown in FIG. 4, a pair of first protrusions 42b and a pair of second protrusions 42c are provided on the rear side as viewed from the opposite side in the optical axis direction when the second region 42 is the front. The first protrusions 42b are arranged at left and right positions sandwiching the pair of terminal insertion holes 42a in the width direction. The second protrusions 42c are arranged at left and right positions sandwiching the pair of first protrusions 42b in the width direction. The detailed configuration of the second region 42 will be described later.

[0025] The fin section 43 creates a heat dissipation path for transmitting heat transferred from the light emitting section 31 to the socket 7, and is provided so as to protrude backward in the optical axis direction from the rear side of the first region 41 to which the light emitting section 31 is fixed, as shown in FIG. 4. The fin section 43 has a plurality of parallel fins 43a in the horizontal direction and a plurality of connecting fins 43b in the vertical direction. The parallel fins 43a are provided in parallel at a predetermined interval in the vertical direction, and the connecting fins 43b are provided to bridge the parallel fins 43a in the vertical direction. For this reason, the fin section 43 is configured such that four parallel fins 43a and two connecting fins 43b are combined in a lattice pattern, and the parallel fins 43a and the connecting fins 43b are connected at their intersections.

[0026] 2 and 3, a pair of positioning protrusions 46 are provided to crimp and fix the circuit board 32 to the heat sink 4, and protrude from left and right positions in the width direction of the second region 42, sandwiching the first region 41 therebetween. The pair of cylindrical positioning protrusions 46 are inserted into a pair of crimping holes 32a of the circuit board 32, and crush and deform the tip portions protruding from the circuit board 32.

[0027] The light source side connector 5 generates a light source side power supply path to the circuit board 32, and is fixed in an embedded state at the bottom of the socket 7 as shown in Figs. 3 and 4. The light source side connector 5 has a pair of power supply side terminal rods 51a, a pair of power supply side terminal rods 51b, and a power supply insulator 52. The pair of power supply side terminal rods 51a protrude from one end surface 52a of the power supply insulator 52, and are inserted into the pair of terminal connection holes 32c through the pair of terminal insertion holes 42a. The tip of the power supply side terminal rod 51a is fixed to the terminal connection hole 32c by soldering. The pair of power supply side terminal rods 51b protrude from the other end surface 52b of the power supply insulator 52, and are electrically connected to the power supply side connector 6.

[0028] The power supply side connector 6 generates a power supply side power supply path to the circuit board 32, and is fixed to the socket 7 by fitting into the socket 7 behind and below a socket heat dissipation section 72 (described later) (see FIG. 1). One end of the power supply side connector 6 is connected to the light source side connector 5, and the other end is connected to the harness 16. In other words, the light source side connector 5, the power supply side connector 6, and the harness 16 form a power supply path from the power source to the circuit board 32.

[0029] The socket 7 incorporates the heat sink 4 and has a heat dissipation function of dissipating heat conducted from the heat sink 4 to the outside. As shown in Figures 2 and 3, the heat sink 4 having the light source 3 on the front side in the optical axis direction is incorporated by fitting. The socket 7 is formed of a resin material with high thermal conductivity, and integrally comprises a socket main body 71 provided on the front side in the optical axis direction and a socket heat dissipation part 72 provided on the rear side in the optical axis direction.

[0030] The socket body 71 is a portion in which the heat sink 4 is assembled. The socket body 71 has a peripheral wall 71a, a flange wall 71b, a mounting protrusion 71d, a groove 71e, and a pair of positioning holes 71g. The peripheral wall 71a is formed in a cylindrical shape extending in the optical axis direction. The flange wall 71b is formed by a stepped surface extending in the outer diameter direction from the rear side of the peripheral wall 71a. The mounting protrusions 71d are formed in a convex shape protruding in the outer diameter direction from four points of the peripheral wall 71a. The groove 71e is formed on the inside of the cylindrical peripheral wall 71a, and is a portion into which the fin portion 43 of the heat sink 4 is fitted, and is formed in a shape that is an inversion of the shape of the fin portion 43. The thermally conductive grease 100 is applied to the groove 71e. The positioning hole 71g is formed in a shape that allows the second protrusion 42c to be inserted.

[0031] The socket heat dissipation section 72 is a section that performs heat dissipation to the outside, and has socket fins 72a consisting of multiple vertical plates that protrude from the rear side in the optical axis direction. The multiple vertical plates that make up the socket fins 72a are arranged in parallel at predetermined intervals in the width direction, ensuring a wide heat exchange area with the outside.

[0032] Next, the configuration of the main parts of the light emitting section 31, the circuit board 32, the bonding wires 33, and the heat sink 4 will be described with reference to FIGS.

[0033] As shown in FIGS. 5 and 6, the light emitting section 31 includes a submount substrate 31a, a pair of light emitting section side terminals 31b, a light emitting chip 31c, a heat conductive adhesive layer 31d, and a light emitting surface 31e.

[0034] The submount substrate 31a is formed in a substantially rectangular shape when viewed from the front side in the optical axis direction, and a pair of light-emitting unit side terminals 31b and a light-emitting chip 31c are fixed to the front surface of the substrate in the optical axis direction. The submount substrate 31a is provided with an electric circuit that electrically connects the light-emitting unit side terminals 31b and the semiconductor element that emits light.

[0035] The pair of light-emitting portion side terminals 31b are square-shaped LED electrode terminals to which one ends of the bonding wires 33 are joined, and are disposed and fixed at the left and right positions on the lower front side of the submount substrate 31a.

[0036] The light emitting chip 31c has an LED (Light Emitting Diode) built-in, emits light from a rectangular light emitting surface 31e with the long side in the width direction when viewed from the front, and is fixed at a position on the front and upper side of the submount substrate 31a. When applied to a vehicle lamp using the above-mentioned light guide member, the light emitting surface 31e of the light emitting chip 31c is disposed at a position close to the incident surface of the light guide member. Here, the light emitting element built into the light emitting chip 31c is not limited to an LED, and may be other self-emitting semiconductor elements such as an LD chip (laser diode chip) and an EL (organic EL). In the first embodiment, as shown in FIG. 5, four light emitting chips 31c are mounted in a horizontal arrangement, and the four light emitting chips 31c are entirely covered by the rectangular light emitting surface 31e. However, the number of light emitting chips 31c is not limited to four as long as one or more light emitting chips are used. Furthermore, when a plurality of light emitting chips 31c are used, the arrangement is not limited to a horizontal arrangement, but may be a vertical arrangement or a combination of a horizontal arrangement and a vertical arrangement.

[0037] The thermally conductive adhesive layer 31d is an adhesive layer formed of a thermally conductive adhesive that bonds and fixes the submount substrate 31a to the front surface of the heat sink 4. Here, the thermally conductive adhesive refers to an adhesive compound obtained by adding a metal or ceramic with high thermal conductivity as a filler to a resin adhesive such as an epoxy, silicon, or acrylic adhesive.

[0038] As shown in Figures 5 and 6, the circuit board 32 has a pair of crimping holes 32a, a pair of curved holes 32b, a pair of terminal connection holes 32c, a pair of board side terminals 32d, and an adhesive sheet 32e.

[0039] The pair of crimping holes 32a are provided on the left and right sides of the board cutout 32g. The positioning protrusions 46 of the heat sink 4 are inserted into the respective crimping holes 32a, and the tips of the positioning protrusions 46 are crushed and deformed, thereby crimping and fixing the circuit board 32 to the heat sink 4.

[0040] The pair of curved holes 32b are provided at positions between the pair of crimping holes 32a and the board cutout portion 32g, respectively, and are formed in a curved shape within a predetermined angle range.

[0041] The pair of terminal connection holes 32c are provided on the left and right sides below the board cutout 32g. Each of the terminal connection holes 32c is provided at a corresponding position that overlaps with each of the left and right terminal insertion holes 42a in the optical axis direction when the circuit board 32 is attached to the front side of the heat sink 4. The power supply side terminal rods 51a are inserted into the terminal connection holes 32c. The terminal connection holes 32c and the power supply side terminal rods 51a are electrically connected to each other on the front side of the terminal connection holes 32c via soldering (not shown).

[0042] The pair of board-side terminals 32d are provided on the left and right sides between the board cutout portion 32g and the terminal connection hole portion 32c in the vertical direction, and are rectangular board pad terminals to which the other ends of the bonding wires 33 are joined. When the light-emitting portion 31 and the circuit board 32 are attached to the heat sink 4, the pair of board-side terminals 32d are located outside the pair of light-emitting portion side terminals 31b in the width direction.

[0043] The adhesive sheet 32e is a sheet that fixes the circuit board 32 to the front surface of the heat sink 4, and is a tape-shaped sheet made of a material such as an epoxy resin adhesive, a silicon resin adhesive, or an acrylic resin adhesive (see FIG. 3). The adhesive sheet 32e has cutouts at portions corresponding to the crimping hole 32a, the curved hole 32b, and the terminal connection hole 32c of the circuit board 32. Note that the adhesive sheet 32e may be in a liquid or fluid form instead of a tape form.

[0044] The pair of bonding wires 33 are bonded at both ends to the light-emitting unit side terminal 31b and the board side terminal 32d by a wire bonding method using ultrasonic vibration, and a strip-shaped metal material (e.g., strip-shaped aluminum material, etc.) is used. By bonding the bonding wires 33, two sets of terminals consisting of the light-emitting unit side terminal 31b and the board side terminal 32d are electrically connected to each other via the pair of bonding wires 33. Here, the "wire bonding method" refers to a method in which a processing environment is prepared using a jig and ultrasonic vibration is applied from a bonding capillary to perform solid-state bonding, and has the advantage of being able to bond at low temperatures and causing little denaturation of the material.

[0045] The heat sink 4 divides its circular front area into a first area 41 to which the light emitting section 31 is directly fixed, and a second area 42 to which the circuit board 32 is directly fixed.

[0046] As shown in FIG. 5, the first region 41 is divided into a T-shaped region that is a combination of a first arcuate region located at the upper part of the front circular region of the heat sink 4 when viewed from the front, and a first rectangular region that extends downward from the center of the first arcuate region.

[0047] As shown in FIG. 5, the second region 42 is divided into a U-shaped region that is a combination of a second arcuate region located below the front circular region of the heat sink 4 when viewed from the front, and a pair of second rectangular regions extending upward from the left and right sides of the second arcuate region.

[0048] When the light emitting unit 31 is fixed to the first region 41 and the circuit board 32 is fixed to the second region 42, the light emitting unit 31 is directly fixed to a position on the lower side of a first rectangular region in the T-shaped first region 41, which is the center of the front circular region of the heat sink 4. The circuit board 32 is directly fixed to almost the entire region of the U-shaped second region 42. Note that, in the first region 41 of the heat sink 4, the region consisting of the first arched region above the front circular region and the upper side of the first rectangular region is the region where the front of the heat sink 4 is exposed.

[0049] Next, the positioning of the light-emitting part side terminals 31b provided on the light-emitting part 31 in a front view will be described with reference to Fig. 5. The light-emitting part side terminals 31b are disposed between the light-emitting surface 31e covering the light-emitting chip 31c and the substrate side terminals 32d in a front view. That is, the light-emitting part side terminals 31b on the right side in a front view are disposed within an area F surrounded by four points, namely, a point P1 in the left-right center of the light-emitting surface 31e, an end point P2 of the right lower side of the light-emitting surface 31e, and both end points P3 and P4 of the upper side of the substrate side terminals 32d, and within the submount substrate 31a. The light-emitting part side terminals 31b on the left side in a front view are disposed in the same manner. In other words, when the set positions of the light-emitting surface 31e and the board-side terminal 32d are predetermined, the light-emitting portion side terminal 31b is configured so that when both ends of the bonding wire 33 are joined and fixed to the light-emitting portion side terminal 31b and the board-side terminal 32d, respectively, the bonding wire 33 does not cross over the light-emitting surface 31e or pass over the light-emitting surface 31e.

[0050] Next, the angle range in front view for setting the bonding wire 33 will be described with reference to Fig. 7. First, the allowable angle range in front view for setting the bonding wire 33, which is set by the minimum angle line Lmin and the maximum angle line Lmax passing through the bonding center position of the light-emitting unit side terminal 31b, is defined as the bonding range A (see Fig. 7). At this time, the minimum angle line Lmin (line with angle = 0°) of the bonding range A is set by a first parallel line parallel to the vertical line YL passing through the center position O of the light-emitting surface 31e. Then, the maximum angle line Lmax (line with angle = 90°) of the bonding range A is set by a second parallel line parallel to the horizontal line XL passing through the center position O of the light-emitting surface 31e.

[0051] The angle of the bonding wire 33 in front view is an angle included in the bonding range A, and is set to an angle in the intermediate angle range between the minimum angle line Lmin and the maximum angle line Lmax (for example, an angle of about 45°±10°). That is, when both ends of the bonding wire 33 are bonded to the light-emitting unit side terminal 31b and the board side terminal 32d, respectively, the set angle of the bonding wire 33 is set so as to be disposed furthest from the bonding prohibited range C on the minimum angle line Lmin side and the bonding prohibited range D on the maximum angle line Lmax side. Here, the "bonding prohibited range C" is preferably a range extending about 45° from the minimum angle line Lmin to the negative side. The "bonding prohibited range D" is preferably a range extending about 45° from the maximum angle line Lmax to the positive side.

[0052] Next, the height relationship between the light-emitting unit side terminal 31b, the board side terminal 32d, and the light-emitting surface 31e in a side view in the direction perpendicular to the optical axis will be described with reference to FIG. 8. The height h2 of the light-emitting unit side terminal 31b in a side view is set to a position lower than the height h1 of the light-emitting surface 31e in a side view. The height h2 of the light-emitting unit side terminal 31b in a side view is set to the same position as the height h3 of the board side terminal 32d in a side view, or to a position higher than the height h3 of the board side terminal 32d in a side view (h1>h2≧h3). That is, the relationship between the height h2 of the light-emitting unit side terminal 31b and the height h3 of the board side terminal 32d in a side view is set in consideration of preventing interference between the bonding wire 33 and peripheral members (light-guiding members, etc.) arranged close to the front side of the light-emitting surface 31e in the optical axis direction, and it is sufficient that the height difference (h2-h3) is 0 (zero) or more.

[0053] 8, in Example 1, in order to reduce the height of the bonding wire 33 protruding in the optical axis direction, the height h2 of the light-emitting unit side terminal 31b is set to a position lower than the height h1 of the light-emitting surface 31e and higher than the height h3 of the board-side terminal 32d (h1>h2>h3). Here, when a reference plane (h=0) is set at a predetermined position on the rear side in the optical axis direction from the front surface of the heat sink 4, in the case of the height h1 of the light-emitting surface 31e, the "height h" refers to the height from the reference plane to the light-emitting surface 31e, and in the case of the heights h2 and h3 of the light-emitting unit side terminal 31b and the board-side terminal 32d, the "height h" refers to the height from the reference plane to the surface of each terminal 31b and 32d.

[0054] The first region 41 and the second region 42 of the heat sink 4 are connected by an inclined surface 44, forming a stepped surface with different heights of the regions. The stepped surface is set so that the height H1 of the first region 41 to which the light emitting unit 31 is fixed in a side view is higher than the height H2 of the second region 42 to which the circuit board 32 is fixed in a side view (H1>H2).

[0055] By setting the height H1 of the first region 41 to which the light emitting unit 31 is fixed in a side view as a step surface higher than the height H2 of the second region 42 in a side view, the thickness of the heat sink 4 in the optical axis direction in the first region 41 becomes thicker than the thickness of the heat sink 4 in the optical axis direction in the second region 42 (see FIG. 6). Here, "height H" refers to the height from a reference plane (H=0) set at a predetermined position from the front of the heat sink 4 toward the rear side in the optical axis direction, in the case of height H1 of the first region 41 in a side view, to the surface of the first region 41. Also, in the case of height H2 of the second region 42 in a side view, it refers to the height from the reference plane to the surface of the second region 42.

[0056] Next, the operation of the first embodiment will be described by dividing it into "assembly operation of the light source unit", "heat dissipation operation of the light source unit", and "characteristic operation of the light source unit".

[0057] A description will now be given of the assembly operation of the light source unit 2. First, as shown in Fig. 3, the light source side connector 5 is inserted and fixed into the socket 7 by fitting.

[0058] Next, the light emitting unit 31 is attached to the heat sink 4. At this time, the light emitting unit 31 is directly fixed to the first region 41 of the heat sink 4 by a thermally conductive adhesive. Next, the circuit board 32 is directly fixed to the second region 42 of the heat sink 4 by an adhesive sheet 32e. Next, the positioning protrusions 46 of the heat sink 4 are inserted into the crimping holes 32a of the circuit board 32, and the tip ends of the positioning protrusions 46 are crushed and crimped. As a result, the circuit board 32 is crimped and fixed to the heat sink 4. Next, both ends of the bonding wire 33 are joined to the left and right light emitting unit side terminals 31b and the left and right board side terminals 32d by a wire bonding method using ultrasonic vibration.

[0059] Next, the heat sink 4 to which the light emitting unit 31, the circuit board 32, and the bonding wires 33 are attached is fixed to the socket 7 for assembly. At this time, thermally conductive grease 100 is applied to the groove 71e of the socket 7. Next, the second protrusions 42c of the heat sink 4 are inserted into the positioning holes 71g of the socket 7. Next, the heat sink 4 and the socket 7 are fixed with an adhesive. During this fixing operation, the fins 43 of the heat sink 4 are fitted into the grooves 71e of the socket 7 by the positioning action of the second protrusions 42c of the heat sink 4 and the positioning holes 71g of the socket 7.

[0060] Next, the power supply side terminal bar 51a of the light source side connector 5 and the terminal connection hole portion 32c of the circuit board 32 are soldered to be electrically connected to the front side of the circuit board 32. Through the above-mentioned assembly procedure, the light source unit 2 is assembled.

[0061] In recent years, LEDs have been increasingly used in vehicle lighting, and new designs have made it possible to reduce the size and number of parts required, which has resulted in demands for higher output and brightness from a single LED. However, the tradeoff with higher output from LEDs is that they generate more heat, and there is a demand for more efficient heat dissipation.

[0062] The light emitting portion 31 of the light source unit 2 is directly fixed to the first region 41 of the heat sink 4 by a thermally conductive adhesive. In other words, a heat sink mounting structure is adopted in which the LED is directly mounted on the heat sink 4. Therefore, the heat generated from the light emitting portion 31 is directly conducted to the heat sink 4. Next, the heat conducted to the heat sink 4 is conducted from the fin portion 43 of the heat sink 4 to the socket 7. At this time, the fin portion 43 of the heat sink 4 and the groove portion 71e of the socket 7 are in close proximity to each other via the thermally conductive grease 100, so that the heat from the heat sink 4 is efficiently conducted to the socket 7. Then, the heat conducted to the socket 7 is dissipated to the outside from the socket heat dissipation portion 72 of the socket 7.

[0063] In this way, the light source unit 2 employs a heat sink mounting structure for the light emitting section 31, and therefore has improved heat dissipation performance compared to a substrate mounting structure for the light emitting section. Here, the substrate mounting structure for the light emitting section refers to a structure in which an LED light emitting chip, which is the light emitting section, is provided on the upper surface of a circuit board, as described in, for example, JP 2013-247062 A.

[0064] In Example 1, the first region 41 and the second region 42 are configured such that the first region 41 is a stepped surface with a higher height, and the heat sink thickness in the optical axis direction of the first region 41, to which the light emitting unit 31 is directly fixed, is set to be thicker than the heat sink thickness of the second region 42, to which the circuit board 32 is directly fixed.

[0065] Therefore, the heat capacity of the first region 41 of the heat sink 4, to which the light-emitting unit 31 is directly fixed, is greater than the heat capacity of the second region 42. For this reason, when heat generation from the light-emitting unit 31 continues and the temperature of the light-emitting unit 31 attempts to rise due to a heat balance in which the amount of heat generated is greater than the amount of heat dissipated, the amount of heat dissipated by the heat sink 4 is greater than when the heat sink thickness is the same. As a result, the difference between the amount of heat generated by the light-emitting unit 31 and the amount of heat dissipated by the heat sink 4 is kept small, and the temperature rise of the light-emitting unit 31 can be effectively suppressed.

[0066] In the first embodiment, the light-emitting unit side terminal 31b provided on the light-emitting unit 31 and the board-side terminal 32d provided on the circuit board 32 are electrically connected by a bonding wire 33. At this time, the light-emitting unit side terminal 31b is disposed at a position between the light-emitting surface 31e covering the light-emitting chip 31c and the board-side terminal 32d when viewed from the front.

[0067] That is, the position of the light-emitting unit side terminal 31b is determined based on the set position of the light-emitting surface 31e and the set position of the board-side terminal 32d. Therefore, when both ends of the bonding wire 33 are bonded and fixed to the light-emitting unit side terminal 31b and the board-side terminal 32d, respectively, the bonding wire 33 is disposed at a position that does not interfere with the light-emitting surface 31e and is separated from the light-emitting surface 31e. Therefore, the bonding wire 33 does not cross the light-emitting surface 31e or interfere with a part of the light-emitting surface 31e. As a result, it is possible to prevent the bonding wire 33 from blocking the light emitted from the light-emitting surface 31e.

[0068] In the first embodiment, the allowable angle range in the front view for setting the bonding wire 33, which is set by the minimum angle line Lmin and the maximum angle line Lmax passing through the bonding center position of the light-emitting unit side terminal 31b, is called the bonding range A. In this case, the minimum angle line Lmin of the bonding range A is set by a first parallel line parallel to the vertical line YL passing through the center position O of the light-emitting surface 31e.

[0069] That is, in the first embodiment, the minimum angle line Lmin of the bonding range A is set by a first parallel line parallel to the vertical line YL passing through the center position O of the light emitting surface 31e, so that the pair of bonding wires 33 are set at an angle that is greater than the vertical parallel arrangement in the front view. This makes it possible to prevent the pair of bonding wires 33 from crossing each other. In addition, it is possible to prevent the pair of bonding wires 33 from interfering with peripheral unit components (e.g., capacitor 32f, etc.) that are arranged in inner positions close to each other (see FIG. 7).

[0070] In the first embodiment, the maximum angle line Lmax of the bonding range A is set by a second parallel line that is parallel to the horizontal line XL passing through the center position O of the light emitting surface 31e.

[0071] That is, in the first embodiment, the maximum angle line Lmax of the bonding range A is set by a second parallel line parallel to the horizontal line XL passing through the center position O of the light emitting surface 31e, so that the pair of bonding wires 33 are set at an angle that is smaller than a straight line arrangement that spreads horizontally in a front view. This makes it possible to prevent interference between the pair of bonding wires 33 and peripheral unit components (such as positioning protrusions 46 for fixing the circuit board 32 to the heat sink 4) that are arranged at outer positions away from each other (see FIG. 7).

[0072] In the first embodiment, the angle of the bonding wire 33 in a front view is set to an angle included in the bonding range A and in the intermediate angle range between the minimum angle line Lmin and the maximum angle line Lmax.

[0073] That is, in the first embodiment, the bonding wires 33 are set at an angle in the intermediate angle range between the minimum angle line Lmin and the maximum angle line Lmax, so that the pair of bonding wires 33 are set at an angle of about 45° on both sides when viewed from the front (=V-shaped arrangement) as shown in FIG. 5. Therefore, the pair of bonding wires 33 are placed at a position farthest from the capacitor 32f and the positioning protrusion 46, which are peripheral unit components. Therefore, a setting area for the jig used in the wire bonding method is secured, and a sufficient distance is secured between the bonding capillary and the peripheral unit components. As a result, interference between the pair of bonding wires 33 and the peripheral unit components can be reliably prevented, and the bonding operation by the wire bonding method can be performed smoothly without any hindrance.

[0074] In the first embodiment, the height h2 of the light-emitting unit side terminal 31b in a side view is set to a position lower than the height h1 of the light-emitting surface 31e in a side view. The height h2 of the light-emitting unit side terminal 31b in a side view is set to a position higher than the height h3 of the board-side terminal 32d in a side view.

[0075] That is, in the first embodiment, the light-emitting unit side terminal 31b and the board side terminal 32d are disposed at a position farther away from the peripheral members than the light-emitting surface 31e. Therefore, the bonding wire 33 connecting the light-emitting unit side terminal 31b and the board side terminal 32d is disposed so that the distance from the peripheral members (such as the light-guiding member E) is secured even if the bonding wire 33 is curved so as to protrude in the optical axis direction as shown in FIG. 8. As a result, when the peripheral members such as the light-guiding member E and the inner lens are disposed close to the front side of the light-emitting surface 31e in the optical axis direction, the bonding wire 33 can be prevented from interfering with the peripheral members such as the light-guiding member E and the inner lens. In particular, when the light source unit 2 is attached while being rotated in application to the vehicle lamp 1, interference with the peripheral members can be prevented even when the light source unit 2 is attached.

[0076] In Example 1, the first region 41 and the second region 42 of the heat sink 4 are formed as stepped surfaces, and the stepped surface is set so that the height H1, as viewed from the side, of the first region 41 to which the light-emitting unit 31 is fixed is set at a position higher than the height H2, as viewed from the side, of the second region 42 to which the circuit board 32 is fixed.

[0077] That is, in the first embodiment, the first region 41 and the second region 42 of the heat sink 4 are formed on a stepped surface, and the height H1 of the first region 41 is set to be higher than the height H2 of the second region 42. Therefore, when the light emitting portion 31 is fixed to the surface of the first region 41 and the circuit board 32 is fixed to the surface of the second region 42, the relationship of heights h1, h2, and h3 (h1>h2≧h3) is established between the light emitting surface 31e, the light emitting portion side terminal 31b, and the board side terminal 32d in a side view. Therefore, without the need for ingenuity in setting the light emitting portion or the thickness setting of the board, the relationship of heights h1, h2, and h3 in a side view can be easily obtained to prevent interference between the pair of bonding wires 33 and the peripheral members arranged close to the front side in the optical axis direction of the light emitting surface 31e. In addition, by setting the height H1 of the first region 41 in a side view to be higher than the height H2 of the second region 42 in a side view, it is possible to make the thickness of the heat sink 4 in the first region 41 to which the light-emitting section 31 is fixed thicker than the thickness of the second region 42, thereby achieving even greater heat dissipation efficiency.

[0078] As described above, the vehicle lamp 1 of the first embodiment provides the following effects.

[0079] (1) In a vehicle lamp 1 including a light-emitting section 31 having a light-emitting element, a circuit board 32, and a heat sink 4, a front area of ​​the heat sink 4 is divided into a first area 41 and a second area 42, the light-emitting section 31 is fixed to the first area 41, the circuit board 32 is fixed to the second area 42, the light-emitting section side terminal 31b provided on the light-emitting section 31 and the board side terminal 32d provided on the circuit board 32 are electrically connected by a bonding wire 33, and the light-emitting section side terminal 31b is disposed at a position between the light-emitting surface 31e covering the light-emitting element and the board side terminal 32d in a front view. This improves the heat dissipation performance from the light-emitting section 31 while preventing the bonding wire 33 from blocking the light emitted from the light-emitting surface 31e.

[0080] (2) The bonding range A is an allowable angle range in front view for setting the bonding wires 33, which is set by a minimum angle line Lmin and a maximum angle line Lmax passing through the bonding center position of the light-emitting unit side terminal 31b. The minimum angle line Lmin of the bonding range A is set by a first parallel line parallel to a vertical line YL passing through the center position O of the light-emitting surface 31e. This makes it possible to prevent the pair of bonding wires 33 from crossing each other, and also to prevent interference with peripheral unit components arranged in inner positions where the pair of bonding wires 33 approach each other.

[0081] (3) The maximum angle line Lmax of the bonding range A is set by a second parallel line parallel to the horizontal line XL passing through the center position O of the light emitting surface 31e. This makes it possible to prevent interference between the pair of bonding wires 33 and peripheral unit components that are arranged at outer positions away from each other.

[0082] (4) The angle of the bonding wires 33 in a front view is set to an angle included in the bonding range A and in the intermediate angle range between the minimum angle line Lmin and the maximum angle line Lmax. This not only reliably prevents interference between the pair of bonding wires 33 and the peripheral unit components, but also enables smooth and unhindered bonding operations using the wire bonding method.

[0083] (5) The height h2 of the light-emitting unit side terminal 31b in a side view is set to a position lower than the height h1 of the light-emitting surface 31e in a side view. The height h2 of the light-emitting unit side terminal 31b in a side view is set to the same height position as the height h3 of the board-side terminal 32d in a side view, or to a position higher than the board-side terminal 32d. Therefore, when a peripheral component is disposed close to the front side in the optical axis direction of the light-emitting surface 31e, it is possible to prevent the bonding wire 33 from interfering with the peripheral component.

[0084] (6) The first region 41 and the second region 42 of the heat sink 4 are formed into a stepped surface, and the stepped surface is set so that the height H1 of the first region 41 to which the light emitting unit 31 is fixed in a side view is set at a position higher than the height H2 of the second region 42 to which the circuit board 32 is fixed in a side view. Therefore, as the height relationship between the light emitting unit side terminals 31b, the board side terminals 32d, and the light emitting surface 31e in a side view, it is possible to easily set a height relationship that can prevent interference between the bonding wires 33 and peripheral members arranged close to the front side of the light emitting surface 31e in the optical axis direction.

[0085] The vehicle lamp 1 of the present disclosure has been described above based on Example 1, but the specific configuration is not limited to Example 1, and design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim in the scope of the claims.

[0086] In the first embodiment, an example was shown in which the light-emitting unit 31 and the circuit board 32 are arranged in a divided arrangement in which the light-emitting unit 31 is arranged in the center of the front area of ​​the heat sink 4, and the circuit board 32 is arranged in an area surrounding the lower part and both sides of the light-emitting unit 31. However, the divided arrangement of the light-emitting unit and the circuit board is not limited to the divided arrangement in the first embodiment, and includes submount types with various divided arrangements. For example, the light-emitting unit may be arranged in the center of the front area of ​​the heat sink, and the circuit board may be arranged in an area surrounding the upper part and both sides of the light-emitting unit. In addition, the light-emitting unit may be arranged in the center of the front area of ​​the heat sink, and the circuit board may be arranged to surround the entire circumference of the light-emitting unit. Furthermore, an example may be such that a plurality of light-emitting unit setting holes are provided in the circuit board, and a plurality of light-emitting units are scattered in the circuit board.

[0087] In the first embodiment, the heat sink 4 is exemplified by forming the first region 41 and the second region 42, which divide the front region, on a stepped surface. However, the heat sink may be exemplified by forming the front region on the same plane, and determining a boundary line dividing the first region and the second region within the same plane.

[0088] In the first embodiment, an example was shown in which the angle of the bonding wire 33 in a front view is set to an angle included in the bonding range A and in an intermediate angle range between the minimum angle line Lmin and the maximum angle line Lmax. However, the angle setting of the bonding wire is not limited to the angle setting of the first embodiment. In short, the settable bonding range and the optimal setting angle of the bonding wire may differ depending on the type of submount used. Therefore, even an angle outside the bonding range A shown in the first embodiment may be acceptable as the setting angle of the bonding wire.

[0089] In the first embodiment, an example is shown in which the present invention is applied to a vehicle lamp 1 including a socket-type modular light source unit 2 that integrates a light source 3, a heat sink 4, a light source side connector 5, a power supply side connector 6, and a socket 7. However, the vehicle lamp to which the present invention is applied is not limited to a vehicle lamp including a socket-type modular light source unit, and can be applied to any vehicle lamp that includes at least a light emitting portion, a circuit board, and a heat sink.

[0090] In the first embodiment, an example has been shown in which the vehicle lamp 1 of the present disclosure is applied to a reflective type lamp that uses a reflective surface 13a (reflector 13) of a vehicle such as an automobile. However, the present disclosure is not limited to this, and the vehicle lamp 1 of the present disclosure may be applied to a lamp that uses a projection lens, or may be applied to a light guide type lamp in which a light guide member is disposed in front of a light source (light emitting portion). [Explanation of symbols]

[0091] 1 Vehicle lighting fixtures 2 Light source unit 3 light source 31 Light emitting part 31b Light emitting part side terminal 31e Light-emitting surface 32 Circuit Board 32d Board side terminal 33 Bonding Wire 4 Heat sink 41 First area 42 Second area A Bonding Range Lmin minimum angle line Lmax maximum angle line YL vertical line XL horizontal line h1 Height of the light emitting surface 31e as viewed from the side h2 Height of the light-emitting unit side terminal 31b in a side view h3 Height of board side terminal 32d as viewed from the side H1 Height of the first region 41 in a side view H2 Height of the second region 42 in a side view X Width direction (horizontal direction) Y Up / down direction (vertical direction) Z Optical axis direction (back and forth direction)

Claims

1. A vehicle lamp including a light emitting unit having a light emitting element, a circuit board, and a heat sink, Dividing a front area of ​​the heat sink into a first area and a second area, fixing the light emitting unit to the first area, and fixing the circuit board to the second area; a light-emitting portion side terminal provided on the light-emitting portion and a board side terminal provided on the circuit board are electrically connected by a pair of bonding wires; the light-emitting unit side terminal is disposed at a position between a light-emitting surface covering the light-emitting element and the board side terminal in a front view; the circuit board has a peripheral unit component disposed at an inner position where the pair of bonding wires are close to each other, and a peripheral unit component disposed at an outer position where the pair of bonding wires are separated from each other, The bonding range is defined as an allowable angle range in a front view for setting the bonding wire, which is defined by a minimum angle line and a maximum angle line passing through the bonding center position of the light-emitting unit side terminal. A minimum angle line of the bonding range is set by a first parallel line parallel to a vertical line passing through a center position of the light emitting surface; The maximum angle line of the bonding range is set by a second parallel line that is parallel to a horizontal line passing through a center position of the light emitting surface; The angle of the bonding wire as viewed from the front is set to an angle included in the bonding range and in a middle angle range between the minimum angle line and the maximum angle line. A vehicle lamp characterized by the above.

2. In the vehicle lamp described in claim 1, a height of the light-emitting unit side terminal in a side view is set to a position lower than a height of the light-emitting surface in a side view; The height of the light-emitting unit side terminal in a side view is set to the same height as the height of the board side terminal in a side view, or to a higher height than the board side terminal. A vehicle lamp characterized by the above.

3. In the vehicle lamp described in claim 2, The first region and the second region of the heat sink are formed on a stepped surface, The step surface is configured so that the height of the first region to which the light emitting unit is fixed, as viewed from the side, is set to a position higher than the height of the second region to which the circuit board is fixed, as viewed from the side. A vehicle lamp characterized by the above.

Images