High heat-radiant optical device substrate

Abstract

An optical device substrate includes metal plates and insulating layers formed between the metal plates. Each insulating layer includes a cured insulating layer formed by curing insulating material and an anodized layer merged with each metal plate, the anodized layer formed by anodizing a first metal and a second metal of each metal plate. The first metal and the second metal include a first anodized layer and a second anodized layer, respectively, and are electrically insulated by interfaces including a first interface formed between the first metal and the first anodized layer, a second interface formed between the first anodized layer and the cured insulating layer, a third interface formed between the cured insulating layer and the second metal and a fourth interface formed between the second anodized layer and the second metal.

Claims

1. An optical device substrate comprising metal plates and insulating layers formed between the metal plates, wherein each insulating layer includes a cured insulating layer formed by curing insulating material and an anodized layer merged with each metal plate, the anodized layer formed by anodizing a first metal and a second metal of each metal plate, the first metal and the second metal include a first anodized layer and a second anodized layer, respectively, and are electrically insulated by interfaces including a first interface formed between the first metal and the first anodized layer, a second interface formed between the first anodized layer and the cured insulating layer, a third interface formed between the cured insulating layer and the second anodized layer and a fourth interface formed between the second anodized layer and the second metal.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is of views illustrating individual steps of a process of manufacturing an optical device substrate according to a conventional technique;

(2) FIG. 2 is a flowchart illustrating a process of manufacturing an optical device substrate according to the present invention;

(3) FIG. 3 is a flowchart illustrating individual steps of a process of packaging an optical device on the optical device substrate according to the present invention;

(4) FIGS. 4 to 7 are views illustrating individual steps of the process of manufacturing an optical device substrate according to the present invention; and

(5) FIGS. 8 and 9 are views illustrating an LED packaged on the optical device substrate according to the present invention.

MODE FOR INVENTION

(6) Hereinafter, a detailed description will be given of the present invention with reference to the appended drawings.

(7) FIG. 2 is a flowchart illustrating a process of manufacturing an optical device substrate according to an embodiment of the present invention, and FIG. 3 is a flowchart illustrating individual steps of a process of packaging an optical device on the optical device substrate according to the present invention.

(8) As illustrated in FIG. 2, the method of manufacturing the optical device substrate according to the present invention includes providing metal plates 100 (S1), anodizing the metal plates 100 (S2), applying a liquid binder 101 on the anodized surfaces of the metal plates 100 (S3), alternately stacking the metal plates 100 coated with the liquid binder 101 and binder films 102 (S4), curing a laminate including the metal plates 100 and the binder films 102 using hot pressing (S5), cutting the laminate including the metal plates 100 and the binder films 102 in the same direction as the stacking direction (S6), and processing the cut surface of the resulting substrate to form a reflector cup having a bottom surface 501 and an inclined surface 502 extending therefrom (S7).

(9) As illustrated in FIG. 3, packaging an optical device 400 on the optical device substrate 300 according to the present invention includes bonding an optical device 400 to the optical device substrate 300 (S8), wire-bonding the optical device 400 to an electrode 100 (S9), and forming a protective layer 407 to enclose the optical device 400 and the conductive wire 405.

(10) Below is a detailed description of the method of manufacturing the optical device substrate 300 as illustrated in FIG. 2 and the packaging of the optical device 400 as illustrated in FIG. 3, with reference to FIGS. 4 to 9.

(11) Upon providing the metal plates 100 (S1), as illustrated in FIG. 4, a plurality of metal plates 100 is provided, and preferably, the metal plates 100 have a rectangular shape and are made of aluminum, an aluminum alloy, magnesium or a magnesium alloy. The other shapes or materials may be adopted, as necessary.

(12) Subsequently, upon anodizing (S2), the metal plates 100 have porous oxide films formed on the surfaces thereof by means of an anodizing process. Because the formed oxide films have a large surface area, a bonding force between the metal plates 100 and the liquid binder 101 which will be subsequently applied thereon may be enhanced, and also insulating properties between the metal plates 100, namely, voltage resistance, may be improved. As such, the anodizing process is typical and a description thereof is thus omitted.

(13) Subsequently, upon applying the liquid binder 101 (S3), as illustrated in FIG. 5, the anodized surfaces of the metal plates 100 are coated with an insulative liquid binder 101.

(14) As such, the liquid binder 101 has a viscosity adapted to infiltrate pores of the oxide films formed on the metal plates 100, so that the liquid binder 101 finely infiltrates the oxide films. Thereby, the bonding area between the liquid binder 101 and the oxide films may be enlarged, thus enhancing the bonding force between the liquid binder 101 and the metal plates 100.

(15) In order to allow the liquid binder 101 to finely infiltrate the oxide films, the viscosity of the liquid binder 101 at room temperature ranging from 5 C. to 40 C. is preferably set to 0.11 Pa.Math.s.

(16) Selectively, in order to enable the liquid binder 101 to finely infiltrate the oxide films, the viscosity of the liquid binder 101 is preferably set to 0.010.03 Pa.Math.s in the thermal treatment temperature range of 80100 C. in the course of heating in the subsequent curing step. In this case, the liquid binder 101 may finely infiltrate the oxide films in the thermal treatment temperature range of 80100 C., and the viscosity thereof is drastically increased while gradually increasing the thermal treatment temperature from 100 C. to 200 C., so that this binder is cured in a state of finely infiltrating the oxide films.

(17) The liquid binder 101 may be made of a polymer- or epoxy-based resin, and a thermosetting resin may be used so as to prevent changes in phase under external conditions after curing.

(18) Subsequently, upon stacking the metal plates 100 and the insulative binder films 102 (S4), as illustrated in FIG. 6, before the liquid binder 101 applied on the metal plates 100 is cured, the metal plates 100 coated with the liquid binder 101 and a plurality of insulative resin binder films 102 are alternately stacked to form a laminate. The resin binder films 102 may be formed of a polymer- or epoxy-based resin, and a thermosetting resin may be used so as to prevent changes in phase under external conditions after curing.

(19) In the case where an optical device substrate 300 is manufactured by stacking the metal plates 100 coated with only the insulative liquid binder 101, the liquid binder 100 may bubble upon thermal curing, and thus the insulating layers 303 of the optical device substrate 300 are remarkably decreased in mechanical strength, undesirably making it easy to break the optical device substrate 300. However, in the present invention, when an optical device substrate 300 is manufactured by stacking the metal plates 100 coated with the insulative liquid binder 101 and the insulative resin binder films 102, bubbling of the liquid binder 101 may be suppressed during thermal curing, and thereby mechanical strength of the optical device substrate 300 may be enhanced and fragility of the liquid binder after curing may be decreased.

(20) Also, in the case where an optical device substrate 300 is manufactured by stacking the metal plates 100 coated with only the insulative liquid binder 101, the liquid resin may flow down and thus the thickness of the insulating layers 303 of the optical device substrate 300 may become very non-uniform, and also it is very difficult to manufacture the optical device substrate 300 having the insulating layers 303 at a predetermined thickness or more. However, in the present invention, as an optical device substrate 300 is manufactured by stacking the metal plates 100 coated with the insulative liquid binder 101 and the insulative resin binder films 102, the thickness of the insulating layers 303 of the optical device substrate 300 is made uniform, and may also be precisely controlled.

(21) Subsequently, upon curing (S5), the laminate including the metal plates 100 and the binder films 102 is hot pressed, so that the applied liquid binder 101 and the binder films 102 are cured. As such, when the pressure applied to both ends of the laminate is 210 kg/cm.sup.2, the liquid binder may finely infiltrate the oxide films of the metal plates and also excessive mechanical impact may be prevented from being applied to the binder films.

(22) Subsequently, upon cutting the laminate 200 (S6), the cured laminate 200 including the metal plates 100 and the binder films 102 is cut in the same direction as the stacking direction. For example, when the laminate 200 is cut in the same direction as the stacking direction of the laminate 200 based on the cut lines 202 as illustrated in FIG. 6, rectangular optical device substrates 300 may be manufactured, with a predetermined thickness and including the metal layers 100 and the insulating layers 303 which are repeated, as illustrated in FIG. 7.

(23) Thereafter, forming the reflector cup (S7) may be further performed. As illustrated in FIG. 8, the cut surface of the optical device substrate 300 is processed using a cutting tool, thus forming a reflector cup having a bottom surface 501 and an inclined surface 502 extending therefrom. Such a reflector cup is effective at emitting light forward from the optical device 400.

(24) Before or after forming the reflector cup (S7), forming a plating layer 601 on the optical device substrate 300 may be implemented. The plating layer 601 functions to increase reflectivity of light generated from the optical device 400 to thus increase light efficiency, and also to improve welding properties of a conductive wire 405 to the optical device substrate 300 in the subsequent wire-bonding procedure, thus enhancing bondability.

(25) As such, the plating layer 601 may be formed of any one or more selected from among silver (Ag), gold (Au), nickel (Ni), copper (Cu), and palladium (Pd), and the plating layer may be formed using electric plating or electroless plating.

(26) Selectively, the upper surface of the optical device substrate 300 on which an optical device 400 is mounted is plated with Ag having high reflectivity to increase light reflectivity, and the lower surface of the optical device substrate 300 is plated with Ag, Au or Cu having good bondability to solder balls, thus enhancing soldering properties upon mounting the optical device substrate 300 on a printed circuit board (PCB).

(27) Subsequently, as illustrated in FIG. 7, upon bonding the optical device (S8), a plurality of LED devices 400 is bonded at a predetermined interval to the metal layer 100 of the optical device substrate 300. Then, upon wire-bonding (S9), the LED devices 400 each are wire-bonded to the edge of one side of the metal layer 100 facing thereto with the insulating layer 303 being interposed therebetween. Then, upon forming the protective layer 407 (S10), the protective layer 407 is formed on the LED devices 400. Herein, bonding the LED devices 400 to the metal layer 100, wire-bonding the LED devices 400, and forming the protective layer 407 on the LED devices 400 are typical and thus a detailed description thereof is omitted.

(28) Thereafter, when the packaged optical device substrate 300 is cut in a transverse direction and a longitudinal direction along the cut lines 305, 307 of FIG. 7, as illustrated in FIGS. 8 and 9, each LED device 400 may constitute a single optical device packaging module. Alternatively, when the packaged substrate is cut only in a longitudinal direction along the cut lines 307 of FIG. 7, a plurality of LED devices 400 may constitute a single optical device packaging module.

(29) The packaged optical device substrate 300 is configured as illustrated in FIGS. 8 and 9, wherein the metal electrodes 100 are derived from the metal plate 100, and the insulating layers 101, 102, 103 are respectively derived from the insulative liquid binder 101, the insulative binder film 102, and the oxide film of the metal plate 100. Two metal electrodes 100 are spaced apart from each other by the insulating layers 101, 102, 103, and the optical device 400 is bonded to one metal electrode 100 of the two metal electrodes 100 and wire-bonded to the other metal electrode 100, and is also sealed by the protective layer 407. Therefore, because the optical device is bonded onto the metal electrodes, heat dissipation becomes very effective.

(30) Although the embodiments of the present invention regarding the high heat-radiant optical device substrate and the method of manufacturing the same have been disclosed for illustrative purposes, those skilled in the art will appreciate that a variety of different variations and modifications are possible, without departing from the spirit and scope of the invention. Thus, the above embodiments should be understood not to be limited but to be illustrated.

(31) The scope of the present invention should be determined by the claims which will be described later, and should be understood to incorporate all variations, equivalents and modifications within the spirit and scope of the present invention defined by the claims.

DESCRIPTION OF THE REFERENCE NUMERALS IN THE DRAWINGS

(32) TABLE-US-00001 100: metal plate 101: liquid binder 102: binder film 200: laminate 300: optical device substrate 303: insulating layer 202, 305, 307: cut line 400: optical device, LED 405: conductive wire 407: protective layer 501: bottom surface 502: inclined surface 601: plating layer 100: metal layer, metal electrode 101, 102, 103: insulating layer