JP2015179641A - Vehicular lighting fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat radiation properties by suppressing increase in cost by using a flat plate-like metal circuit board.SOLUTION: A vehicular lighting fixture includes: a light source arranged on a circuit board; and a reflector having a reflection surface for reflecting light from the light source into a predetermined direction. The circuit board has: a flat plate-like metal substrate; a circuit pattern formed on the metal substrate via an insulating layer; and an insulation protection layer for covering the circuit pattern. The reflector has: a reflection surface formation part including a reflection surface; and a base part for supporting the reflection surface formation part. The base part has a contact surface for coming into contact with the metal substrate, and includes a metal deposition film in a region including the contact surface. That is, in the circuit board, the metal substrate comes into contact with the contact surface via the metal deposition film.

Description

  The present invention relates to a vehicular lamp including a reflector, and more particularly to a vehicular lamp using a circuit board on which a light source is arranged.

  Patent Document 1 discloses a vehicular lamp that includes a light source mounted on a heat dissipation member.

JP 2012-216348 A

  The vehicular lamp as disclosed in Patent Document 1 radiates heat generated in the light source to the outside through the heat dissipation member by disposing the light source on the heat dissipation member including the fins.

  However, the use of a heat dissipating member provided with fins has a problem that the vehicular lamp is increased in size and weight.

  In addition, it is also considered to use a flat metal circuit board as the circuit board on which the light source is arranged. However, in order to improve heat dissipation, the thickness and size of the circuit board are increased, which increases the cost. There was a problem of increasing.

  Therefore, there has been a problem of using a flat metal circuit board to obtain high heat dissipation while suppressing an increase in thickness and size.

  Then, this invention solves the said subject and aims at providing the vehicle lamp with high heat dissipation using the flat metal circuit board.

The vehicular lamp according to the present invention includes a light source disposed on a circuit board and a reflector having a reflection surface that reflects light from the light source in a predetermined direction. The circuit board includes a flat metal substrate, a circuit pattern formed on the metal substrate via an insulating layer, and an insulating protective layer that covers the circuit pattern.
The reflector has a reflecting surface forming part having a reflecting surface and a base part that supports the reflecting surface forming part, and the base part has an abutting surface that comes into contact with the metal substrate, and deposits metal in a region including the corresponding contacting surface. With a membrane. The circuit board is attached to the reflector so that the surface of the metal substrate exposed on the side opposite to the light source mounting side is in contact with the contact surface through the metal vapor deposition film.

  According to the vehicular lamp of the present invention, it is possible to improve heat dissipation by suppressing an increase in cost by using a flat metal circuit board.

1 is a schematic plan view of a vehicular lamp according to an embodiment of the present invention. It is a schematic sectional drawing in alignment with the AA of FIG. (A) It is a schematic perspective view of the vehicle lamp of the Example of this invention. (B) It is a schematic sectional drawing of the white light source vicinity in the vehicle lamp of the Example of this invention. (A) It is a schematic top view of the vehicle lamp of the Example of this invention. (B) It is a schematic bottom view of the vehicle lamp of the Example of this invention. It is a schematic sectional drawing explaining the vehicle lamp of the other Example of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. As long as there is no description, it is not restricted to these embodiments.

  Below, the vehicle lamp which concerns on the Example of this invention is demonstrated, referring FIGS. 1-4. In the following description, the terms “front” and “rear” mean the direction viewed from the vehicle lamp unless otherwise specified.

FIG. 1 is a plan view of a vehicular lamp 10 according to an embodiment of the present invention as seen from the irradiation direction. FIG. 2 is a schematic cross-sectional view taken along line AA in FIG. FIG. 3A is a schematic perspective view of the vehicular lamp 10 according to the embodiment of the present invention. (B) It is a schematic sectional drawing of the white light source vicinity in the vehicle lamp of the Example of this invention. Fig.4 (a) is a schematic top view of the vehicle lamp of the Example of this invention. FIG. 4B is a schematic bottom view of the vehicular lamp according to the embodiment of the present invention. In FIG. 4A, for easy description, a formation area of a contact surface 3221a (not described) that does not appear on the upper surface is shown by a dotted line.
This vehicular lamp 10 includes a plurality of light sources 1, a circuit board 2 on which the light sources 1 are mounted, and an optical system including a reflector 3, and is used as a headlamp.

As the light source 1, a light source mounted with a light emitting element 11 such as a semiconductor light emitting element can be used.
The light source 1 is mounted on the circuit board 2 and is electrically connected to the circuit pattern 23 formed on the circuit board 2 by a conductive bonding material (solder, Ag paste, etc.), a conductive wire or the like.

In this embodiment, four white light sources each including the semiconductor light emitting element 11 and the wavelength conversion layer 12 including a phosphor are used as the light source 1.
In this embodiment, the white light source 1 includes a wavelength conversion layer 12 including a blue-emitting InGaN LED chip 11 and a yellow-emitting YAG phosphor. The white light source 1 is configured so that light emitted from the LED chip 11 passes through a wavelength conversion layer 12 including a phosphor, and the blue light from the LED chip and a part of the light emitted from the LED chip are formed by the phosphor. White light is obtained by the mixed light with the converted yellow light.
In the present embodiment, the four light sources are mounted on the respective circuit boards 2, and are fixed to accommodating portions each having an opening 33 formed in the reflector 3.

The circuit board 2 includes a flat metal substrate 21, a circuit pattern 23 formed on the metal substrate 21 via an insulating layer, and an insulating protective layer 24 covering the circuit pattern 23.
The metal substrate 21 can be made of a metal having high thermal conductivity such as Al (aluminum) or Cu (copper).
The circuit pattern 23 is formed on one main surface of the metal substrate 21 by being appropriately insulated from the metal substrate 21.
The insulating protective layer 24 is formed on the circuit pattern 23 and the metal substrate 21. The insulating protective layer 24 is not formed in a region where the light source 1 is mounted or a region for electrical connection with the light source 1.
The back surface of the metal substrate 21 (the surface opposite to the side on which the light source is mounted) is not formed with the insulating protective layer 24 and is exposed.
In this embodiment, an Al substrate having an insulating layer 22 made of alumite formed on one surface is used as the metal substrate 21, a circuit pattern 23 made of metal is formed on the insulating layer 22, and a resist layer made of resin is used as an insulating protective layer. What was formed as 24 was used as the circuit board 2. The back surface of the circuit board 2 is constituted by the back surface of the metal substrate 21, that is, Al is exposed on the back surface.

  The circuit board 2 is formed with insertion holes 25 and 26 and screw insertion holes 27 corresponding to the heat caulking pins and positioning pins formed on the reflector side in order to join the reflector 3.

  The reflector 3 includes a curved reflecting surface forming portion 31 and a substantially flat base portion 32 that supports the reflecting surface forming portion 31. The reflecting surface forming part 31 and the base part 32 are formed integrally.

As shown in FIG. 2, the reflector 2 has metal vapor deposition films 31 </ b> A, 31 </ b> B, 321 </ b> A, and 322 </ b> A formed on the molded resin substrate 5. The metal vapor deposition films 31A, 31B, 321A, and 322A are made of a metal having a high reflectance such as Al or Ag.
In the present embodiment, metal deposited films 31A, 31B, 321A and 322A made of Al were formed.
In the present embodiment, the metal vapor deposition films 31A, 31B, 321A, and 322A are formed in a range indicated by an arrow in FIG. That is, it is formed on the reflecting surface 31a in the reflecting surface forming portion 31, the surface on the side opposite to the reflecting surface, and the surface on the reflecting surface forming portion side in the base portion. That is, the metal vapor deposition film includes a metal vapor deposition film 31A formed on the reflection surface 31a in the reflection surface formation portion 31, a metal vapor deposition film 31B formed on the surface opposite to the reflection surface, and a reflection surface formation portion in the base 32. It consists of metal vapor deposition films 321A and 322A formed on the side surface.

  In the reflective surface forming part 31, a metal vapor deposition film 31A formed in a region irradiated with light from the light source 1 forms a reflective surface 31a. The reflection surface 31a forms a paraboloid and forms an optical system. The focal line of the reflecting surface 31a is arranged so as to substantially coincide with the line shape in which a plurality of white light sources are arranged. That is, the reflector 3 irradiates the front side of the vehicle with the light emitted from the white light source on the reflective surface 31 a of the reflective surface forming unit 31.

The base 32 is configured integrally with the reflective surface forming portion 31 and supports the reflective surface forming portion 31.
A circuit board 2 on which a light source is mounted is attached to the base 32.
An opening 33 for inserting and arranging the circuit board 2 on which the light source is mounted is formed in the base 32. The opening 33 is configured such that the end of the reflection surface forming portion 31 is exposed.
The base 32 has a front base 321 on the front side of the opening 33 and a rear base 322 on the rear side of the opening 33, and the front side of the circuit board 2 is attached to the front base 321, and the rear side of the circuit board 2 is attached to the rear base 322. It is done.

A positioning pin 3211 and a heat caulking pin 3212 are formed on the front base portion 321. The circuit board 2 and the reflector 3 are positioned by inserting the positioning pin 3211 through the insertion hole 25 formed on the front side of the circuit board 2. The heat caulking pin 3212 is inserted into the insertion hole 26 formed on the front side of the circuit board 2 and the head of the pin is thermally deformed, whereby the circuit board 2 is heat caulked, and the circuit board 2, the reflector 3, Is fixed in a positioned state.
A screw hole 3222 is formed in the rear base 322. The circuit board 2 and the reflector 3 are fixed by inserting the screw 4 together with the screw insertion hole 27 formed on the rear side of the circuit board 2.

The front base 321 and the rear base 322 are not on the same plane as each other, but are formed such that the front base 321 is closer to the reflective surface side than the rear base 322. Therefore, the front base 321 is fixed to the light source mounting side of the circuit board, and the rear base 322 is fixed to the side opposite to the light source mounting side of the circuit board 2.
By fixing the front base 321 to the light source mounting side of the circuit board 2, it is possible to facilitate the work of applying heat deformation such as a heat chip to the heat caulking pin 3212 formed on the front base 321.
By fixing the rear base 322 to the side opposite to the light source mounting side of the circuit board 2, the surface of the metal substrate 21 in the circuit board 2 and the metal vapor deposition film 322 </ b> A formed on the rear base 322 can be brought into contact with each other. .

Also in the base portion 32, metal vapor deposition films 321A and 322A are formed on the surface on the reflective surface forming portion 31 side.
The metal vapor deposition film 321A formed on the front base 321 mainly forms an appearance that is integral with the reflecting surface 31a when the vehicular lamp is viewed from the outside.
The metal vapor deposition film 322A formed on the rear base 322 forms a contact surface 3221a with the back surface of the circuit board (surface opposite to the light source mounting side). At the contact surface 3221a, the metal vapor deposition film 322A and the back surface of the circuit board are in contact with each other. By forming a contact surface 3221a on the back surface of the circuit board with the metal vapor deposition film 322A formed on the rear base 322, the heat generated from the light source 1 is transferred to the metal vapor deposition film 322A from the metal substrate 21 on the contact surface 3221a. Heat can be efficiently transferred as heat transfer between them and diffused to the metal vapor deposition film 322 </ b> A formed on the rear base 322. Therefore, the heat dissipation can be improved by the metal vapor deposition film 322A formed on the rear base 322.
In particular, the metal vapor deposition film 322A formed on the rear base 322 is formed not only in the contact area with the circuit board 2 but also in a wider range than the contact area including the contact area. Therefore, heat is diffused to the metal vapor deposition film 322A formed continuously in the contact area, and heat is radiated from the metal vapor deposition film 322A other than the contact area to the outside.

As in this embodiment, the rear base 322 is preferably formed with a convex contact portion 3221 for forming a contact surface 3221a of the circuit board 2 with the metal substrate 21 (see FIG. 2). ). By forming the upper surface of the convex abutting portion 3221 as the abutting surface 3221a, the abutting surface 3221a having a predetermined area can be reliably formed, so that stable heat dissipation characteristics can be obtained.
In the present embodiment, the convex contact portion 3221 has a rectangular top surface and is formed at four locations. Therefore, a rectangular contact surface 3221a is formed as indicated by a dotted line in FIG.

In the vehicle lamp of the present invention, the metal substrate 21 of the circuit board 2 and the metal vapor deposition film (especially 322A) of the reflector 3 are in contact with each other at the contact surface 3221a. Therefore, heat generated from the light source can be transferred to the metal vapor deposition film (especially 322A) via the contact surface 3221a, and the metal vapor deposition film (particularly 322A) formed on the reflector 3 can be used for heat dissipation to the outside. .
Further, the metal vapor deposition film (especially 322A) of the reflector is formed not only on the contact surface 3221a but also on the peripheral region of the contact surface, and heat generated from the light source is applied to the metal vapor deposition film on the peripheral region of the contact surface. Can also be thermally diffused to efficiently dissipate heat.
Further, by forming a convex contact portion 3221 on the reflector and making the convex surface of the contact portion 3221 a contact surface 3221a, stable heat dissipation characteristics can be obtained.
Therefore, according to the vehicular lamp of the present invention, not only the heat generated in the light source is radiated through the metal substrate, but also the heat is transferred and diffused to the metal vapor deposition film formed on the reflector through the contact surface. Therefore, heat dissipation can be improved.
In addition, the heat dissipation can be improved by suppressing the increase in cost as compared with the case of increasing the size and thickness of the metal substrate or using a heat sink having fins.

  Note that the vehicular lamp of the present invention is not limited to the above-described embodiment, and it is needless to say that various changes are made without departing from the gist of the present invention.

  For example, in the above embodiment, the contact surface is formed by the partially convex contact portion in consideration of the actual situation of the surface accuracy of the reflector, but the entire region overlapping the metal substrate is the contact surface. Can be formed.

  For example, in the above-described embodiment, the contact portion is formed in a rectangular shape at four locations as shown by dotted lines in FIG. 4, but can be formed in an arbitrary shape and area, and formed in series. You can also.

  For example, in the above-described embodiment, the contact portion is formed at one place with respect to one circuit board as shown in FIG. Alternatively, it may be formed near the light source.

  For example, in the above embodiment, the headlamp is described as the vehicle lamp, but the present invention can be applied to all vehicle lamps such as a fog lamp, a daytime running lamp, and a rear combination lamp.

  For example, in the above-described embodiments, the optical system including the reflector is described as the optical system. However, the present invention can also be applied to a projector-type optical system that includes a reflector and a projection lens.

  For example, in the above embodiment, an LED chip is used as the semiconductor light emitting element, but an LD (laser diode) chip can be used instead of the LED chip.

  For example, in the above embodiment, the reflector has been described as having a structure in which a metal vapor deposition film is laminated on the molded resin substrate 5, but an appropriate layer may be laminated to add a function, for example, an undercoat layer, a topcoat layer, etc. Etc. may be provided. However, even in this case, at least the contact surface is made of a metal material, and no layer other than the metal material is formed on the metal vapor deposition film 322A at the contact portion. And it is preferable not to form layers other than a metal material on the metal vapor deposition film 322A formed on the rear base 322.

  For example, in the above embodiment, a white light source in which a wavelength conversion layer having a substantially uniform thickness is disposed on a semiconductor light emitting element is used. However, the shape and position of the phosphor layer can be appropriately changed. For example, a white light source in which a dome-shaped wavelength conversion layer is disposed on a semiconductor light emitting element may be used.

  For example, in the above embodiment, a blue light emitting LED chip is used as the semiconductor light emitting element and a yellow light emitting phosphor is used as the phosphor, but an ultraviolet light emitting LED chip is used as the semiconductor light emitting element, and a blue light emitting phosphor and a yellow light emitting phosphor are used as the phosphor. It is good also as a structure to use.

For example, in the above embodiment, the light source is a white light source, but a light source of another emission color may be used.

1: Light source 11: Light emitting element 12: Wavelength conversion layer 2: Circuit board 21: Metal substrate 22: Insulating layer 23: Circuit pattern 24: Insulating protective layer 25: Positioning pin insertion hole 26: Thermal caulking pin insertion hole 27: Screw insertion Hole 3: Reflector 31: Reflecting surface forming portion 31a: Reflecting surface 32: Base portion 321: Front base portion 3211: Positioning pin 3212: Heat caulking pin 322: Back base portion 3221: Contact portion 3221a: Contact surface 3222: Screw hole 33: Openings 3A, 31A, 31B, 321A, 322A: Metal deposition film 4: Screw 5: Molded resin base 10: Vehicle lamp

Claims (3)

A light source disposed on a circuit board;
A reflector having a reflecting surface for reflecting light from the light source in a predetermined direction,
The circuit board has a flat metal substrate, a circuit pattern formed on the metal substrate via an insulating layer, and an insulating protective layer covering the circuit pattern,
The reflector has a reflecting surface forming portion including the reflecting surface, and a base that supports the reflecting surface forming portion,
The base has a contact surface that contacts the metal substrate, and includes a metal vapor deposition film in a region including the contact surface.
The vehicle lamp according to claim 1, wherein the circuit board is attached to the reflector so that a surface of the metal substrate is in contact with the contact surface. The vehicular lamp according to claim 1, wherein the metal deposition film is formed in a range wider than the contact surface at the base. The vehicular lamp according to claim 1, wherein the abutting surface is configured as a surface of a convex abutting portion formed on the base portion.

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