KR-20260067160-A - METAL CORE PRINTED CIRCUIT BOARD

Abstract

The present invention relates to a metal printed circuit board. The metal printed circuit board according to the present invention is a metal printed circuit board on which an LED package is mounted on a surface, comprising: a base layer made of a metal material; an insulating layer formed on one surface of the base layer; a circuit pattern portion formed on the insulating layer; and a solder layer soldered to a mounting area in which the LED package is mounted on the metal printed circuit board. The base layer comprises a first metal layer comprising a metal of a first material; and a second metal layer formed on the surface of the first metal layer facing the insulating layer, comprising a metal of a second material having a coefficient of thermal expansion different from that of the first metal material.

Inventors

• 채기훈

Assignees

• 현대모비스 주식회사

Dates

Publication Date

20260512

Application Date

20241105

Claims (6)

1. In a metal printed circuit board on which an LED package is mounted on the surface, Metal base layer; An insulating layer formed on one surface of the above base layer; A circuit pattern portion formed on the insulating layer above; and The above LED package includes a solder layer soldered to a mounting area, which is a region on the metal printed circuit board where the above LED package is mounted. The above base layer is, A first metal layer comprising a metal of a first material; and A metal printed circuit board comprising a second metal layer formed on the surface of the first metal layer facing the insulating layer, and comprising a second metal layer having a coefficient of thermal expansion different from that of the first metal material.
2. In paragraph 1, The above base layer is, A metal printed circuit board comprising a bimetal in which a first metal layer and a second metal layer, which are different types of metals having different coefficients of thermal expansion, are bonded.
3. In paragraph 1, The metal of the second material above is a metal printed circuit board having a smaller coefficient of thermal expansion compared to the metal of the first material above.
4. In paragraph 1, A metal printed circuit board in which the thickness of the first metal layer is greater than the thickness of the second metal layer.
5. In paragraph 1, A metal printed circuit board in which the first metal is made of aluminum and the second metal is made of copper.
6. In paragraph 1, The above circuit pattern portion is applied to the upper surface and further comprises a coating layer containing a photosensitive dye material, and The above coating layer is a metal printed circuit board formed in an area other than the mounting area.

Description

Metal printed circuit board The present invention relates to a metal printed circuit board. Light-Emitting Diodes (LEDs) are used as light sources for automotive lamps due to their high light conversion efficiency, relatively low power consumption, and excellent stability. Since LEDs emit high temperatures, metal core printed circuit boards (PCBs) are used to dissipate the high heat generated, particularly in high-output LED lamps such as main light source lamps, ADB matrix lamps, and multi-source signal lamps, as well as in lamps utilizing multiple LEDs as light sources. A metal core PCB, generally referred to as a heat-dissipating metal substrate, means a PCB made with a metal base material. A metal core PCB consists of a structure comprising a copper or aluminum-based base plate, an insulating layer, and a circuit pattern. An MCPCB assembly is completed by mounting LED packages onto the mounting pads of the metal core PCB through a soldering process. Since the base plate of a metal-cored PCB is metal, it offers good thermal conductivity in the heatsink portion; however, it tends to have a higher coefficient of thermal expansion (CTE) compared to standard FR-4 PCBs. Because MCPCB assemblies consist of numerous components and circuit patterns, there is a high probability of damage, such as cracks, caused by thermal shock in environments fluctuating between high and low temperatures due to differences in material properties, particularly differences in the coefficient of thermal expansion. In particular, the solder joints are problematic because cracks frequently occur due to the difference in thermal expansion between the metal base plate, which has a high coefficient of thermal expansion, and the main material of the LED package, which has a low coefficient of thermal expansion. To address these issues, methods to change the material of LED package components or solder are currently under development; however, they are insufficient to satisfy both the trends of high output, miniaturization, and high-density integration of electronic components, as well as cost considerations. FIG. 1 is a cross-sectional view illustrating a metal printed circuit board according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a base layer applied to a metal printed circuit board according to an embodiment of the present invention, and is a cross-sectional view illustrating the deformation of the base layer according to temperature change. Figure 3 is a cross-sectional view illustrating a metal printed circuit board according to a comparative example. Figure 4 is a diagram schematically comparing the amount of length deformation according to the difference in the coefficient of thermal expansion at different temperatures of the base layer, the support substrate, and the solder layer joint of the LED package according to the comparative example. Hereinafter, embodiments of the present invention will be described in detail according to the attached drawings. First, the embodiments described below are suitable for illustrating the technical features of the metal printed circuit board of the present invention. However, the present invention is not limited to the embodiments described below, nor are the technical features of the present invention limited by the described embodiments; various modifications are possible within the technical scope of the present invention. FIG. 1 is a cross-sectional view illustrating a metal printed circuit board according to an embodiment of the present invention, FIG. 2 is a schematic diagram illustrating a base layer applied to a metal printed circuit board according to an embodiment of the present invention, illustrating the deformation of the base layer according to a temperature change, FIG. 3 is a cross-sectional view illustrating a metal printed circuit board according to a comparative example, and FIG. 4 is a diagram schematically comparing the amount of length deformation according to the difference in the coefficient of thermal expansion of the base layer according to the comparative example, the support substrate of the LED package, and the solder layer joint according to the temperature. Referring to FIGS. 1 and 2, an embodiment of the present invention relates to a metal printed circuit board (10) on which an LED package (70) is mounted on the surface. The LED package (70) includes an LED chip (74), which is a semiconductor device that emits light, a support substrate (73) on which the LED chip (74) is mounted, and a lead frame (not shown), which is a metal plate for electrical connection. The support substrate (73), which is the main material, may be made of a ceramic material with a low coefficient of thermal expansion. The unexplained reference numeral 72 is an LED pad. An LED package (70) configured as described above can be attached to the surface of a metal printed circuit board (10) according to the present invention in a surface mounting m