Laser diode mounting substrate for automotive lamp module

Provided is a laser diode mounting substrate for an automotive lamp module using a laser diode. The substrate includes: a substrate body with a power supply circuit pattern, which electrically connects a connector with a contact point of the laser diode, on the top; a first heat conduction layer disposed at the area except for the power supply circuit pattern, on the top of the substrate body; and a second heat conduction layer disposed on the bottom of the substrate body, in which at least one heat transfer hole is disposed through the first heat conduction layer, the substrate body, and the second heat conduction layer. Therefore, the present invention provides an effect that heat generated by the laser diode can be effectively dissipated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of Korean Patent Application No. 10-2013-0032502 filed in the Korean Intellectual Property Office on Mar. 27, 2013, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a laser diode mounting substrate, and more particularly, to a laser diode mounting substrate for an automotive lamp module using a laser diode.

BACKGROUND ART

LEDs (Light Emitting Diode) or light bulbs are generally used as the light sources of automotive lamps. Recently, there has been an effort to use laser diodes for the automotive light sources, but an efficient technology has not been proposed up to now.

Presently, laser diodes are generally used in the medical and industrial fields. The laser diode (LD), a general term of lightwave oscillators and amplifiers using stimulated emission of photons by optical transition of electrons in semiconductors, has two electrodes. The laser diodes have the advantages that they are small in size and light in various lasers and can be manufactured in large quantities at low costs through semiconductor processes.

However, the laser diodes that are under development now for automotive lamp modules have a problem in that they are difficult to use for vehicles, because the structures are complicated and the heat sinks for heat dissipation are large in size. In particular, the existing substrates mounted with laser diodes have configurations having difficulty in effective heat dissipation, because the other regions except for the circuit patterns are in insulation.

SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide a laser diode mounting substrate that uses a laser diode, has a simple structure and a compact size, and can be used for an automotive lamp module.

The present invention provides a laser diode mounting substrate that can effectively dissipate heat generated by a laser diode.

An embodiment of the present invention provides a laser diode mounting substrate for an automotive lamp module using a laser diode, including: a substrate body with a power supply circuit pattern, which electrically connects a connector with a contact point of the laser diode, on the top; a first heat conduction layer disposed at the area except for the power supply circuit pattern, on the top of the substrate body; and a second heat conduction layer disposed on the bottom of the substrate body, in which at least one heat transfer hole is disposed through the first heat conduction layer, the substrate body, and the second heat conduction layer.

The contact point of the laser diode may be disposed at the center of the substrate body and the connector may be positioned at the center portion of any one of the longitudinal and transverse sides of the substrate body.

The heat transfer holes may be arranged at predetermined gaps in any one of the longitudinal and transverse directions.

The first heat conduction layer and the second heat conduction layer may be formed by plating the substrate with copper.

At least one fastening hole through which fastening members are inserted to fasten other parts may be disposed through the first heat conduction layer, the substrate body, and the second heat conduction layer.

According to embodiments of the present invention, it is possible to effectively dissipate heat generated by the laser diode by fastening the upper heat sink and the lower heat sink to the top and the bottom of the substrate. In particular, since the top and the bottom of the laser diode mounting substrate are plated with copper and the heat transfer holes are disposed through them, it is possible to more effectively dissipate heat by connecting the upper heat sink and the lower heat sink so that they can transmit heat, in addition to fixing the laser diode and supplying power.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in the specification, in giving reference numerals to components throughout the drawings, it should be noted that like reference numerals designate like components even though the components are illustrated in different drawings. Although exemplary embodiments of the present invention will be described hereafter, the spirit of the present invention is not limited thereto and may be modified and implemented in various ways by those skilled in the art.

FIG. 1is a view illustrating an automotive lamp module that is equipped with a laser diode mounting substrate according to an embodiment of the present invention andFIG. 2is an exploded view of the automotive lamp module ofFIG. 1.

FIGS. 1 and 2illustrates only main characteristic parts for conceptually clear understanding of the present invention, so various modifications are expected in the figures and the scope of the present invention is not limited to the specific shapes illustrated in the figures.

Referring toFIGS. 1 and 2, an automotive lamp module100that is equipped with a laser diode mounting substrate120according to an embodiment of the present invention may include a laser diode110, a lower heat sink130, an upper heat sink140, a phosphor150, a collimator160, and a phosphor holder170.

The laser diode110is mounted on the top of the laser diode mounting substrate120. The lower heat sink130is coupled to the bottom of the laser diode mounting substrate120and the upper heat sink140is coupled to the top of the laser diode mounting substrate120. The collimator160, phosphor150, and phosphor holder170may be disposed on the upper heat sink140.

The laser diode mounting substrate120supplies power to the laser diode110, and allows the upper heat sink140and the lower heat sink130to transmit heat.

FIG. 3is a view illustrating the top of a laser diode mounting substrate according to an embodiment of the present invention,FIG. 4is a view illustrating the bottom of the laser diode mounting substrate ofFIG. 3, andFIG. 5is an enlarged view illustrating a cross-section of the laser diode mounting substrate ofFIG. 3.

Referring toFIGS. 3 to 5, the laser diode mounting substrate120may include a substrate body122, a first heat conduction layer123disposed on the top of the substrate body122, and a second heat conduction layer124disposed on the bottom of the substrate body122. A seat126where the laser diode110is mounted may be disposed at the center of the laser diode mounting substrate120.

A power supply circuit pattern122ais disposed on the bottom of the substrate body122. The power supply circuit pattern122aelectrically connects a connector121with the contact point of the laser diode110on the seat126. The connector121may be positioned at the center portion of any one of the longitudinal and transverse sides of the substrate body122. Accordingly, the power supply circuit pattern122amay be elongated from the center of the substrate body122to the center portion of any one of the longitudinal and transverse sides of the substrate body122.

The first heat conduction layer123may be formed by plating the entire top of the substrate body122with copper. The second heat conduction layer124may be formed by plating the other region except for the power supply circuit pattern122aof the bottom of the substrate body122with copper. The first heat conduction layer123and the second heat conduction layer124effectively transmit heat generated by the laser diode110to the upper heat sink140or the lower heat sink130in order to dissipate the heat.

In particular, heat transfer holes125may be disposed through the laser diode mounting substrate120, the first heat conduction layer123, and the second heat conduction layer124and increases the effect of heat dissipation by allowing heat to transfer from the upper heat sink140to the lower heat sink130or from the lower heat sink130to the upper heat sink140.

A plurality of heat transfer holes125may be arranged longitudinally and transversely.

The laser diode mounting substrate120, unlike the existing substrates for the laser diode110, connects the upper heat sink140with the lower heat sink130so that they can transmit heat, in addition to fixing the laser diode110and supplying power.

On the other hand, fastening holes127for coupling the upper heat sink140and the lower heat sink130may be disposed at the corners of the laser diode mounting substrate120. It is possible to fasten the laser diode mounting substrate120, the lower heat sink130, and the upper heat sink140by inserting fasteners such as bolts into the fastening holes127.

The lower heat sink130is fastened to the bottom of the laser diode mounting substrate120and dissipates heat generated by the laser diode110to the outside.

Referring toFIGS. 2 and 6, the upper heat sink140is fastened to the top of the laser diode mounting substrate120and dissipates heat generated by the laser diode110to the outside. A light channel141in which the laser diode110is inserted is disposed through the upper heat sink140. The light channel141, which is disposed through the center of the bottom and the center of the top of the upper heat sink140, fixes the laser diode110and provides a space allowing the light emitted from the laser diode110to travel out of the upper heat sink140.

The lower portion of the light channel141may function as a holder that fixes the laser diode110. Accordingly, the lower portion of the light channel141may be appropriately disposed to fit to the size of the laser diode110and a specific structure for coupling may be disposed.

A connector seat142, a recess where the connector121is inserted and received, may be disposed on the bottom of the upper heat sink140which is brought in contact with the laser diode mounting substrate120.

The phosphor150is positioned ahead of the laser diode110in the light channel141. The phosphor140can convert the light emitted from the laser diode110into white light.

Meanwhile, the collimator160may be positioned between the laser diode110and the phosphor150in the light channel141.

The phosphor holder170can fix the phosphor150to the top of the upper heat sink140. In an embodiment, the phosphor holder170, as illustrated inFIG. 2, may have a slit portion171covering the light channel141and coupling portions172extended from the slit portion171. A slit is cut in the slit portion171. The slit of the slit portion171may be designed in the size making the optical efficiency the highest when white light is made by reaction of the light from the laser diode110with the phosphor150. The slit of the slit portion171may be formed in a rectangular shape for easy optical design, similar to the existing automotive light sources such as LEDs and bulbs.

As indicated by the arrows inFIG. 6, the heat generated by the laser diode110is dissipated to the outside through the upper heat sink140and the lower heat sink130. In particular, heat can easily transfer between the heat sinks through the laser diode mounting substrate120with the first heat conduction layer123and the second heat conduction layer124, and more heat can transfer between the upper heat sink140and the lower heat sink130through the heat transfer holes125.