The present invention relates to a substrate for an optical device, and, more particularly to a substrate for an optical device, which is configured to connect an optical element substrate and an electrode substrate in a fitting manner, and simultaneously, to form one or more bridge pads, which are insulated from the optical element substrate by a horizontal insulating layer, on the optical element substrate.
Generally, a light emitting diode (LED), which is semiconductor light-emitting device, has attracted considerable attention as an environment-friendly light source not causing environmental pollution in various fields. Recently, as the usage of LEDs was spread into various fields, such as interior and exterior illuminations, vehicle headlights, back-light units (BLUs) for displays, etc., LEDs having high efficiency and excellent heat dissipation characteristics have been required. In order to obtain a high-efficiency LED, the raw material or structure of an LED must be improved, and the structure of a LED package and the raw material used in the same are also required to be improved.
Since a high-efficiency LED generates high heat, when high heat is not effectively dissipated, the temperature of LED becomes high, so the characteristics of LED are deteriorated, thereby decreasing the lifespan of the LED. Therefore, efforts have been made to effectively dissipate the heat generated from such LEDs.
Hereinafter, various light-emitting elements, such as LEDs and the like, are referred to as “optical elements”, and various products, each including one or more optical elements, are referred to as “optical devices”.
Subsequently, as shown in
Subsequently, as shown in
Meanwhile, the rows of the plate-shaped LED array are electrically connected in parallel to each other, and the lines thereof are electrically connected in series to each other. This plate-shaped LED array may be directly made into a product or may be made into a product by dividing the rows and lines into suitable row and line units or a single row and line unit. Moreover, when the plate-shaped LED array is directly used, it is mounted on a metal PCB or is provided at the lower portion thereof with a heat dissipation plate.
However, the above-mentioned conventional substrate for an optical device is problematic in that its conductive strips and insulating strips are attached by an adhesive or thermal pressing, and thus the connections between the conductive strips and the insulation strips are easily damaged by slight impact, bending or warping attributable to carelessness in treatment.
Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a substrate for an optical device, which is not damaged by impact, bending or warping attributable to carelessness in treatment because it is configured to connect an optical element substrate and an electrode substrate in a fitting manner, and simultaneously, not to form a horizontal insulating layer for insulating the optical element substrate into a plurality of regions.
Another object of the present invention is to provide a substrate for an optical device, which is not damaged by impact, bending or warping attributable to carelessness in treatment because it is configured to connect an optical element substrate and an electrode substrate in a fitting manner, and simultaneously, to form one or more bridge pads, which are insulated from the optical element substrate by a horizontal insulating layer, on the optical element substrate.
In order to accomplish the above objects, a first aspect of the present invention provides a substrate for an optical device, including: an optical element substrate which is made of a metal plate and is provided therein with a plurality of optical elements; a pair of electrode substrates which are made of an insulating material to form a conductive layer on at least a portion of the upper surface thereof, are connected to both side surfaces of the optical element substrate, respectively, and are wire-bonded to electrodes of the optical elements; and a fitting means which is formed on the side surfaces of the electrode substrate and the optical element substrate to fit the optical element substrate and the electrode substrate.
In the substrate for an optical device according to the first aspect of the present invention, the optical element substrate may be provided with a cavity including a rectangular groove mounted therein with a plurality of optical elements. Further, the optical element substrate may be provided with a plurality of cavities each including a groove mounted therein with an optical element.
A second aspect of the present invention provides a substrate for an optical device, including: an optical element substrate which is made of a metal plate and is provided therein with a plurality of optical elements; a pair of electrode substrates which are made of a metal material, are connected to both side surfaces of the optical element substrate, respectively, and are wire-bonded to electrodes of the optical elements; a fitting means which is formed on the side surfaces of the electrode substrate and the optical element substrate to fit the optical element substrate and the electrode substrate; and a fitting-type vertical insulating layer which is interposed between the optical element substrate and the electrode substrate so as to be connected to the fitting means.
In the substrate for an optical device according to the second aspect of the present invention, the fitting-type vertical insulating layer may be formed by anodizing the side surface of the optical element substrate and the electrode substrate including the fitting means.
Further, the optical element substrate may be provided with a cavity including a rectangular groove mounted therein with a plurality of optical elements. Further, the optical element substrate may be provided with a plurality of cavities each including a groove mounted therein with an optical element.
In the substrate for an optical device according to first or second aspect of the present invention, the optical element substrate may include a plated layer formed on an upper surface thereof. The substrate for an optical device first or second aspect of the present invention may further include: a horizontal insulating layer formed on at least one plated layer-removed region of the optical element substrate to be electrically connected with the plated layer; and a bridge pad disposed on the horizontal insulating layer to allow electrodes of the optical elements to be electrically connected by wires. In this case, the horizontal insulating layer may be formed in a groove formed in the plated layer-removed region of the optical element substrate.
The substrate for an optical device according to the present invention is advantageous in that it is not damaged by impact, bending or warping attributable to carelessness in treatment because it is configured to connect an optical element substrate and an electrode substrate in a fitting manner, and simultaneously, to form one or more bridge pads, which are insulated from the optical element substrate by a horizontal insulating layer, on the optical element substrate.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.
As described above, the optical element substrate 110-1 may be formed of a metal plate which is made of a metal having high thermal conductivity, for example, aluminum (Al), magnesium (Mg), copper (Cu) or iron (Fe), or an alloy thereof in order to rapidly dissipate the heat generated from the optical elements 160. Further, each of the electrode substrates 120-1 may have a body which is made of a synthetic resin having good treatability and processibility, for example, a polymer, a plastic or a composite thereof because it does not need excellent heat dissipation characteristics compared to the optical element substrate 110-1. Therefore,
Meanwhile, in the present invention, in order to enhance the attachment between the optical element substrate 110-1 and the electrode substrate 120-1, both sides of the optical element substrate 110-1 are provided with protrusions 112, and one side of each of the electrode substrates 120-1 is provided with a groove 122 (refer to the structure in the dotted circle “A”), and thus the optical element substrate 110-1 is attached to each of the electrode substrates 120-1 by fitting the protrusion 112 in the groove 122. In this case, the protrusion 112 and the groove 122 may be formed crosswise over the entire or partial sides of the optical element substrate 110-1 and the electrode substrate 120-1, respectively.
Meanwhile, as shown in the dotted circle “B” of
Meanwhile, as shown in
In the present invention, in order to prevent the optical element substrate 110-1 from being provided with a vertical insulating layer, the optical element substrate 110-1 is provided thereon with at least one horizontal insulating layer 140 electrically insulated from this optical element substrate 110-1, and the horizontal insulating layer 140 is provided thereon with a bridge pad 150 for electrically connecting two adjacent optical elements 160.
Here, the horizontal insulating layer 140 may be formed by attaching a synthetic resin sheet onto the optical element substrate 110-1 using an adhesive or thermal pressing, by curing a liquid epoxy or silicon adhesive or by directly thermal-spray ceramic onto the optical element substrate 110-1. In this case, in order to increase the adhesion between the horizontal insulating layer 140 and the optical element substrate 110-1, the horizontal insulating layer 140 may be formed after making the surface of the optical element substrate 110-1 rough as pretreatment. Meanwhile, in order to prevent the horizontal insulating layer 140 from deteriorating the optical reflection efficiency of the optical element substrate 110-1, the size of the horizontal insulating layer 140 may be reduced, if possible.
The bridge pad 150 may be formed of a metal or alloy sheet having excellent electroconductivity, light reflectance and adhesivity with wire, selected from among gold (Au), silver (Ag), copper (Cu), aluminum (Al), nickel (Ni) and alloys thereof. Preferably, the bridge pad 150 may be formed by attaching a silver (Ag) sheet onto the horizontal insulating layer 140 using an adhesive. The bridge pad 150 may have various shapes, such as a circle, a quadrangle and the like.
Further, the bridge pad 150 may be formed by treating a silicon wafer with the metal material using sputtering, electroplating or electroless plating or treating a plastic or FR4 plate with the metal material using electroplating or electroless plating to form a plated layer, suitably cutting the plated layer and then attaching the cut plated layer onto the horizontal insulating layer 140 using an adhesive. Furthermore, the bridge pad 150 may be formed by directly printing silver (Ag) paste onto the horizontal insulating layer 140 using screen printing. Meanwhile, in order to increase the reliability of wire bonding, an electroless nickel (Ni) plated layer may be additionally formed on the surface of the bridge pad 150. It is preferred that the size of the bridge pad 150 be smaller than that of the horizontal insulating layer 140 such that the electrical insulation between adjacent plated layers 132 of the optical element substrate 110-1 is sufficiently conducted.
Meanwhile, after the optical element substrate 110-1 is attached to the electrode substrates 120, a single plated layer 130 is formed thereon. This single plated layer 130 is separated into a conductive layer 134 and a plated layer 132 by a mechanical process (for example, a cutting process) or a chemical process (for example, an etching process) together with a region in which a horizontal insulating layer 140 is to be occupied, and then subsequent processes may be performed.
Through the above-mentioned processes, a substrate for an optical device is completed. Thereafter, optical elements 160 are mounted on the plated layers 132 provided therebetween with the bridge pad 150 by an adhesive or the like, and then the optical elements 160 are electrically connected to each other by wire bonding through the intermediation of the bridge pad 150. In this case, the respective electrodes of the leftmost and rightmost optical elements 160 are electrically connected to the respective electrode substrates 120-1 through wires 165. In
Meanwhile, in this configuration, it preferred that a sealant 190 be charged in the cavity to a level of the upper surface thereof. In this case, steps may be provided over parts of the optical element substrate 110-3 and the electrode substrate 120-3 including the fitting-type vertical insulating layer 124 therebetween such that the wire 165 connected to the electrode substrate 120-3 is embedded in the sealant 190. The cavity may be formed by a pressing, cutting or etching process in a state in which the optical element substrate 110-3 and the electrode substrate 120-3 are attached by fitting. Unlike this, the cavity and the steps are formed in a state in which the optical element substrate 110-3 and the electrode substrate 120-3 are detached from each other, and then the optical element substrate 110-3 and the electrode substrate 120-3 are attached by fitting.
In
The substrate for an optical device according to the present invention may be variously modified within the scope of the technical idea of the present invention without being limited to the above-mentioned embodiments. The substrate for an optical device according to the present invention may also be applied to a light source for backlight unit in which a plurality of optical elements are serially aligned in a series connection.
100-1˜100-7: optical device
110-1˜110-4: optical element substrate
112: protrusion
120-1˜120-4: electrode substrate
122: groove
124: fitting-type vertical insulating layer
130: plated layer
132: plated layer
134: conductive layer
140: horizontal insulating layer
150: bridge pad
160: optical element
165: wire
180: sealant dam
190: sealant
195: lens
Number | Date | Country | Kind |
---|---|---|---|
10-2011-0070095 | Jul 2011 | KR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/KR2012/005479 | 7/11/2012 | WO | 00 | 1/13/2014 |