WO2012133990A1 - Method for manufacturing high heat-dissipation circuit board appropriate for mounting light emitting diode - Google Patents

Abstract

A method for manufacturing a high heat-dissipation circuit board, according to the present invention, comprises the following steps: forming a nonconductive circuit base layer (230) on a base substrate (210) so as to expose a predetermined portion of the base substrate (210); filling a conductive pad base layer (240) on the base substrate (210) which is exposed by means of the circuit base layer (230); forming a plated layer (260) in which a chemical plated layer (250) and an electric plated layer (255) are consecutively stacked, by forming the chemical plated layer on the circuit base layer (230) and the pad base layer(240) and then forming the electric plated layer on the chemical plated layer; forming a conductive bonding pad layer (270) on the plated layer (260); and forming a structure in which a plated layer pattern (261) and a bonding pad (271) are consecutively stacked on a predetermined portion, which includes the upper portion of the pad base layer (240), by patterning the plated layer (260) and the bonding pad layer (270) so that the circuit base layer (230) is exposed. The present invention does not use a heat bonding, thereby eliminating the concern of bending of the substrate due to heat expansion or heat shrinkage and thus can yield a thinner high heat dissipation circuit board (200). Furthermore, the present invention can use thick and durable base substrates having a variety of forms, thereby enabling various and creative LED lighting, and heat dissipating and light distributing qualities can be maximized even further compared to existing means. In addition, manufacturing cost can be reduced.

Description

Manufacturing method of high heat dissipation circuit board suitable for light emitting diode mounting

The present invention relates to a method for manufacturing a high heat dissipation circuit board suitable for LED mounting, in particular, by configuring a circuit in various types of base boards from thin and flexible to thick and rigid, not only improves heat dissipation efficiency, but also reduces manufacturing cost, resulting in high output. It is to provide a high heat dissipation circuit board manufacturing method more suitable for the mounting of the LED.

Since LED devices have been used mainly for displays until recently, high heat dissipation was not required, resin-based substrates have been used as circuit boards on which LEDs are mounted. However, in recent years, as the application in the lighting field is prominent, heat dissipation measures for products equipped with high-power LEDs have been highlighted, and deterioration of LED light efficiency and lifetime due to heat has emerged as a big problem. In particular, since LED modules are becoming smaller and have a higher output, heat generation is inevitably generated. Therefore, such heat dissipation measures are urgently required.

1 is a view for explaining a circuit board for the LED. As shown in FIG. 1, heat generated in the LED chip 20 is radiated to the air through the LED package 30 and the circuit board 10. In the past, since the LED output was small, a resin substrate such as a glass epoxy substrate (FR-4) or the like was used as the circuit board 10 having the LED element. However, high output LEDs used for lighting use have a low luminous efficiency of 20-30% and a small chip size, so that the amount of heat generated per unit area is very high despite the low overall power consumption.

Therefore, high heat dissipation of the high output LED circuit board is inevitable, and a metal base substrate and a ceramic substrate are used instead of the resin substrate. Since the heat dissipation of the circuit board has a great influence on the performance and life of the LED, the circuit board is an important factor in designing a high output LED product.

2 is a view illustrating a conventional heat dissipation circuit board 100 for a medium output LED. Referring to FIG. 2, the conventional heat dissipation circuit board 100 includes an insulating layer 120 made of a mixture of epoxy and ceramic and a metal wiring layer 131 made of copper or the like on a metal substrate 110 made of copper or aluminum. It has a structure laminated sequentially. A general LED package 30 or a COB type LED package 31 is mounted on the heat dissipation circuit board 100, and the LED 20 therein is electrically connected to the metal wiring layer 131.

3 is a view for explaining a process of manufacturing the heat radiation circuit board 100 of FIG. As shown in FIG. 3, the conventional heat dissipation circuit board 100 sequentially laminates the insulating layer 120 and the metal layer 130 on the metal substrate 110, and then hot-bonds the metal layer 110. It is obtained by patterning 130.

 However, since the above-described conventional heat dissipation circuit board 100 is manufactured through a thermal bonding process, the metal substrate 110 may be bent due to thermal expansion and thermal contraction, and thus the metal substrate 110 may not be thinned. In addition to providing flexibility to 100, the insulating layer 120 is made of a mixture of epoxy and ceramic, and thus has a heat dissipation limit in the application of a high power LED product. Therefore, it is difficult to implement a variety of creative LED lighting.

Therefore, the problem to be solved by the present invention, by using a method other than the thermal bonding method by configuring a circuit in various types of base boards from thin and flexible to thick and rigid, not only improves the heat dissipation efficiency but also the manufacturing cost is low compared to the conventional The present invention provides a method of manufacturing a high heat dissipation circuit board that is more suitable for mounting high power LEDs.

The high heat dissipation circuit board manufacturing method according to the present invention for achieving the above object,

Forming a non-conductive circuit base layer on the base substrate to expose a predetermined region of the base substrate;

Filling a conductive pad base layer on the base substrate exposed by the circuit base layer;

After forming a chemical plating layer on the circuit base layer and the pad base layer, forming an electroplating layer on the chemical plating layer to form a plating layer in which the chemical plating layer and the electroplating layer are sequentially stacked;

Forming a conductive bonding pad layer on the plating layer; And

Patterning the plating layer and the bonding pad layer to expose the circuit base layer to form a structure in which a plating layer pattern and a bonding pad are sequentially stacked on a predetermined region including an upper portion of the pad base layer; Characterized in that comprises a.

The base substrate may be a metal substrate having an insulating layer formed thereon, an aluminum substrate having an aluminum oxide layer formed thereon, or an insulating heat-dissipating plastic substrate containing a thermally conductive ceramic.

In the case where the metal substrate is used as the base substrate, the insulating layer is formed to expose a predetermined region of the metal substrate, and the circuit base layer is formed on the insulating layer to expose the metal substrate. The pad base layer may be formed to be filled on the metal substrate exposed by the insulating layer and the circuit base layer. In this case, the pad base layer may be formed by electroplating a metal including Au, Ag, Al, Cu, Sn, or Ni.

The insulating layer is a liquid coating of a polymer resin containing silicon, epoxy, phenol, acrylic, or polyester, or a liquid coating mixed with a ceramic containing Al 2 O 3, AlN, BN, Si, or SiO 2 is printed thereon. It can be formed by coating and curing on the metal substrate in a manner.

The circuit base layer may include a liquid non-conductive material in which a metal including Au, Ag, Al, Cu, Sn, or Ni is mixed with a polymer resin including silicon, epoxy, phenol, acrylic, or polyester. It may be formed by coating and curing the printing method on the base substrate.

The pad base layer may include a liquid conductive material in which a metal including Au, Ag, Al, Cu, Sn, or Ni and a polymer resin including silicon, epoxy, phenol, acrylic, or polyester is mixed with the base substrate. It may be formed by coating and curing on a printing method.

 The plating layer is preferably thicker than the chemical plating layer of the electroplating layer. The bonding pad layer may include Ni / Au in which Ni and Au are sequentially stacked from the bottom up, or Ni / Ag in which Ni and Ag are sequentially stacked from the bottom up.

Since the present invention does not use the thermal bonding method, there is no need to consider the warpage of the substrate due to thermal expansion and thermal contraction, and thus, the high heat dissipation circuit board 200 can be made thin, and various types of base substrates that are thick and rigid can be used. In addition, various and creative LED lightings can be implemented, and heat dissipation and light distribution can be maximized more than before. And manufacturing costs can be reduced.

1 is a view for explaining a circuit board for the LED;

2 is a view for explaining a conventional heat dissipation circuit board 100 for mid-power LED;

3 is a view for explaining a process of manufacturing the heat radiation circuit board 100 of FIG.

4 is a view for explaining a method of manufacturing a high heat dissipation circuit board 200 according to a first embodiment of the present invention;

5 is a view for explaining a manufacturing method of a high heat radiation circuit board 200 according to a second embodiment of the present invention;

6 is a view for explaining a manufacturing method of a high heat radiation circuit board 200 according to a third embodiment of the present invention;

7 is a view for explaining a manufacturing method of a high heat radiation circuit board 200 according to a fourth embodiment of the present invention;

8 is a view for explaining the advantages of the present invention.

[Description of Major Symbols in Drawing]

200: high heat radiation circuit board

210, 310, 410: base substrate

211: metal substrate

212: insulation layer

230: circuit base layer

240: pad base layer

250: chemical plating layer

255: electroplating layer

260: plating layer

261: plating layer pattern

270: bonding pad layer

271: bonding pads

280: photoresist pattern

311: aluminum substrate

312: aluminum oxide layer

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. The following examples are only presented to understand the content of the present invention, and those skilled in the art will be capable of many modifications within the technical spirit of the present invention. Therefore, the scope of the present invention should not be construed as limited to these embodiments.

[First Embodiment]

4 is a view for explaining a method of manufacturing a high heat radiation circuit board 200 according to a first embodiment of the present invention. Specifically, as shown in Figure 4a, on the metal substrate 211, such as Al, Cu, Mg, Fe having a thickness of 10um ~ 10mm excellent silicon, epoxy, phenol, acrylic, polyester, etc. 100 ~ 200 ℃ by coating 30 ~ 300um thick liquid coating material of polymer resin or liquid coating material mixed with ceramic having high thermal conductivity such as Al ₂ O ₃ , AlN, BN, Si, SiO ₂ By curing at, an insulating layer 212 is formed to prepare a base substrate 210.

Next, as shown in Figure 4b, a liquid mixture of a metal such as Au, Ag, Al, Cu, Sn, Ni and a polymer resin such as silicon, epoxy, phenol, acrylic, polyester excellent in heat resistance and insulation The non-conductive material is coated on the insulating layer 212 with a thickness of 5 to 30 μm by a printing method and cured at 100 to 200 ° C. to form the circuit base layer 230. The circuit base layer 230 is formed on the base substrate 210 so that the base substrate 210 in the area where the pad portion of the LED chip or the package is placed is exposed. The circuit base layer 230 may be non-conductive if there are more polymer resins, although metals are included.

Subsequently, as shown in FIG. 4C, metals such as Au, Ag, Al, Cu, Sn, and Ni, silicon, epoxy, phenol, and the like, which are excellent in heat resistance, are exposed on the base substrate 210 exposed by the circuit base layer 230. The pad base layer 240 is formed by mixing a polymer resin such as acrylic or polyester, filling a liquid conductive material having high thermal conductivity by printing, and curing at 100 to 200 ° C. If the amount of the metal is increased and the amount of the polymer resin is reduced, the pad base layer 240 may have conductivity as described above, unlike the circuit base layer 230.

In addition, the chemical plating layer 250 is formed by plating 0.1 to 6 μm of Cu, Ni, and Sn on the circuit base layer 230 and the pad base layer 240 by a chemical plating method. As shown in FIG. 4D, the electroplating layer 250 and the electroplating layer are formed by plating 5 to 100 μm of Cu, Ni, Sn, or the like on the chemical plating layer 250 by electroplating. A plating layer 260 formed by sequentially stacking 255 is formed. Since the circuit base layer 230 is non-conductive, the chemical plating is performed first, and the electroplating is performed later because the electroplating is more advantageous to form thicker than the chemical plating.

Next, as illustrated in FIG. 4E, Ni / Au or Ni / Ag is electroplated on the plating layer 260 to form a bonding pad layer 270 for wire bonding. The bonding pad layer 270 enhances the adhesive strength during wire bonding during the packaging process of packaging the LED chip, but also improves the reflectance of the LED light. Here, Ni / Au refers to the Ni layer is formed first, the Au layer is formed thereon, Ni is 1 ~ 10um, Au is 0.1 ~ 5um, Ni / Ag is Ni layer is formed first, Ag layer formed thereon That is, Ni preferably has a thickness of 1 ~ 10um, Ag 1 ~ 10um.

Subsequently, after the photoresist pattern 280 is formed on the bonding pad layer 270 as shown in FIG. 4F, as shown in FIG. 4G, the bonding pad is exposed until the circuit base layer 230 is exposed using the etching mask as an etching mask. After etching the layer 270 and the plating layer 260 sequentially, the photoresist layer pattern 280 is removed to form the plating layer pattern 261 and the bonding pads 271 to form a high heat-dissipating circuit board according to the first embodiment of the present invention. Complete 200.

The photoresist pattern 280 should be present at a position to be wire bonded together with the pad base layer 240. This is because the plating layer pattern 261 and the bonding pads 271 may be sequentially stacked on the pad base layer 240 and other positions to be wire bonded.

On the other hand, as shown in Figure 4h from the beginning by using the metal substrate 211 is formed in the concave-convex portion (A) on the back can further improve the heat dissipation efficiency. In this case, the thickness of the base substrate 410 may be increased to some extent.

According to the first embodiment of the present invention, since the thickness of the base substrate 210 can be made very thin by using the plating and printing method instead of the thermal bonding method, flexibility can be given to the substrate. Of course, various types of base substrate 210 may be used that are thick and rigid as in the prior art. Therefore, it is possible to realize a variety of creative LED lighting, it is advantageous in terms of manufacturing cost, and also improve the heat dissipation efficiency.

Second Embodiment

5 is a view for explaining a method of manufacturing a high heat radiation circuit board 200 according to a second embodiment of the present invention. In FIG. 4, the pad base layer 240 is formed on the insulating layer 212. However, in FIG. 5, the pad base layer 240 is directly formed on the metal substrate 211.

Specifically, as shown in FIG. 5A, the base substrate 210 is prepared by forming an insulating layer 212 on the metal substrate 211. At this time, the insulating layer 212 is formed by a printing method so that the metal substrate 211 in the region where the pad portion of the LED chip or the package is placed is exposed. As shown in FIG. 5B, the circuit base layer 230 is formed only on the insulating layer 212 using the same printing method as the insulating layer 212.

Subsequently, as shown in FIG. 5C, polymers such as Au, Ag, Al, Cu, Sn, and Ni and polymers having excellent heat resistance on the exposed metal substrate 211 and polymer resins such as silicone, epoxy, phenol, acryl, and polyester By mixing the liquid conductive material having a high thermal conductivity by printing method to harden at 100 ~ 200 ℃ to form a pad base layer 240, or electroplating Au, Ag, Al, Cu, Sn, Ni, etc. The pad base layer 240 is formed by filling the exposed metal substrate 211 in a manner. Since the exposed metal substrate 211 is electrically conductive, but the uppermost circuit base layer 230 is non-conductive, the pad base layer 240 is formed and filled only on the exposed metal substrate 211 when electroplating.

Subsequently, the chemical plating layer 250 is formed on the circuit base layer 230 and the pad base layer 240 as shown in FIG. 5D, and the electroplating layer 255 is sequentially formed as shown in FIG. 5E. The chemical plating layer 250 and the electroplating layer 255 are sequentially stacked to form a plating layer 260. Next, the bonding pad layer 270 is formed as shown in FIG. 5F, and the patterning process is performed as shown in FIGS. 5G and 5H to complete the high heat dissipation circuit board 200 according to the second embodiment. This patterning process proceeds in the same manner as in the first embodiment.

Third Embodiment

FIG. 6 is a view for explaining a method of manufacturing a high heat dissipation circuit board 200 according to a third embodiment of the present invention. Unlike the first embodiment, the surface of the aluminum substrate 311 is formed as the base substrate 310. Anodizing (anodizing) is characterized by using a 30 ~ 200um surrounded by an aluminum oxide layer 312. The aluminum oxide layer 312 corresponds to the insulating layer 212 of FIG. 4, and the subsequent process is the same as that of the first embodiment (FIG. 4). The aluminum oxide layer 312 does not need to be removed because the thermal conductivity is not bad as about 60 W / mk.

Fourth Embodiment

FIG. 7 is a view for explaining a method of manufacturing a high heat dissipation circuit board 200 according to a fourth embodiment of the present invention. Unlike the first embodiment, a heat dissipation plastic substrate is used as the base substrate 410. to be. Heat dissipation plastic refers to a material having high heat conductivity ceramic mixed with plastic to have heat dissipation and insulation. Heat dissipation plastics are particularly advantageous in terms of cost because they are light and inexpensive, and more advantageous in terms of flexibility.

8 is a view for explaining the advantages of the present invention.

Since the present invention does not use the thermal bonding method, there is no need to consider the warpage of the substrate due to thermal expansion and thermal contraction, and thus, the high heat dissipation circuit board 200 can be made thin, and various types of base substrates that are thick and rigid can be used. In addition, various and creative LED lightings can be implemented, and heat dissipation and light distribution can be maximized more than before. And manufacturing costs can be reduced.

Claims (11)

1. Forming a non-conductive circuit base layer on the base substrate to expose a predetermined region of the base substrate;

   Filling a conductive pad base layer on the base substrate exposed by the circuit base layer;

   After forming a chemical plating layer on the circuit base layer and the pad base layer, forming an electroplating layer on the chemical plating layer to form a plating layer in which the chemical plating layer and the electroplating layer are sequentially stacked;

   Forming a conductive bonding pad layer on the plating layer; And

   Patterning the plating layer and the bonding pad layer to expose the circuit base layer to form a structure in which a plating layer pattern and a bonding pad are sequentially stacked on a predetermined region including an upper portion of the pad base layer; A high heat dissipation circuit board manufacturing method comprising a.
2. The method of claim 1, wherein the base substrate is a metal substrate having an insulating layer formed on an upper surface thereof.
3. The method of claim 1, wherein the base substrate is an aluminum substrate having an aluminum oxide layer formed on a surface thereof.
4. The method of claim 1, wherein the base substrate is an insulating heat-dissipating plastic substrate containing a thermally conductive ceramic.
5. The method of claim 2, wherein the insulating layer is formed to expose a predetermined region of the metal substrate, the circuit base layer is formed on the insulating layer so that the metal substrate is exposed, the pad base layer is the insulating layer And filling the metal substrate exposed by the circuit base layer.
6. 3. The method of claim 2, wherein the insulating layer is a liquid coating of a polymer resin comprising silicon, epoxy, phenol, acryl, or polyester, or a ceramic comprising Al2O3, AlN, BN, Si, or SiO2. The method of manufacturing a high heat dissipation circuit board, characterized in that formed by coating the cured liquid coating on the metal substrate by a printing method.
7. The liquid phase of claim 1, wherein the circuit base layer comprises a metal comprising Au, Ag, Al, Cu, Sn, or Ni and a polymer resin comprising silicon, epoxy, phenol, acryl, or polyester. The non-conductive material of the method of manufacturing a high heat dissipation circuit board, characterized in that formed by coating on the base substrate by curing.
8. The method of claim 1, wherein the pad base layer is a liquid mixture of a metal resin containing Au, Ag, Al, Cu, Sn or Ni and a polymer resin comprising silicon, epoxy, phenol, acrylic or polyester. A method of manufacturing a high heat dissipation circuit board, wherein the conductive material is formed by coating and curing the conductive material on the base substrate.
9. The method of claim 5, wherein the pad base layer is formed by electroplating a metal including Au, Ag, Al, Cu, Sn, or Ni.
10. The method of claim 1, wherein the plating layer is thicker in thickness than the chemical plating layer in the electroplating layer.
11. The method of claim 1, wherein the bonding pad layer is formed of Ni / Au in which Ni and Au are sequentially stacked from the bottom up, or Ni / Ag in which Ni and Ag are sequentially stacked from the bottom up. .

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