KR101109516B1 - Optical module and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an optical module and a method of manufacturing the same. In the related art, an LED module structure has a difficulty in miniaturizing and slimming an optical module because the LED bonded substrate must be bonded to the plastic body and the plastic body must be bonded again to the printed circuit board. There was a problem. In view of the above problems, the present invention is to pattern electrode wirings corresponding to the p- and n-electrodes of a light emitting device on an insulating substrate capable of semiconductor processing, to form an insulating layer for electrically insulating the electrode wirings and other portions, and to obtain wire bonding and Forming the contact of the lead electrode and forming the metal structure by the plating frame to form a reflective film and the lead electrode is formed to apply the metal plating process to the silicon substrate or the insulating substrate to reduce the size and slimming of the optical module have.

Description

Optical module and its manufacturing method {OPTICAL MODULE AND MANUFACTURING METHOD THEREOF}

1 is a perspective view showing a module structure of a conventional side-type light emitting diode.

2 is a cross-sectional view showing in detail the module structure of FIG.

Figure 3 is a cross-sectional / plan view showing a structure of an optical module according to an embodiment of the present invention.

FIG. 4 is a cross-sectional / plan view showing a flip chip bonding structure of the light emitting device of FIG. 3.

5 is a cross-sectional view showing a structure in which a Zener diode is connected in parallel to the optical module of FIG. 3 by a semiconductor process.

FIG. 6 is a cross-sectional / plan view showing a flip chip bonding structure of the light emitting device of FIG. 5; FIG.

DESCRIPTION OF REFERENCE NUMERALS

100 light emitting element 210 electrode wiring

220: insulating layer 230: reflecting film

240: conductive wire 250: reflection film inside

260 conductive metal 270 lead electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical module and a method of manufacturing the same, and more particularly, to an optical module and a method of manufacturing the same, which enable the formation of a metal structure having a high reflectance and a lead electrode for connecting an external power source using a plating mold.

In general, the light emitting device has been used as a display device using simple light emission, but recently, the possibility of a light source having various wavelengths and energy has been studied. A light emitting device such as a light emitting diode or a laser diode uses a group 3-5 or 2-6 compound semiconductor, which is a direct transition compound semiconductor, and has a higher energy efficiency than the conventional light source and can be used for tens of thousands of hours.

The light emitting device outputs light of various wavelengths such as red, green, blue, and ultraviolet rays by the development of thin film growth technology and device materials. That is, the light emitting device outputs efficient white light by using a fluorescent material for ultraviolet light or a blue light emitting diode or by combining red, green, and blue.

In particular, light emitting diodes (LEDs) are being applied to a variety of applications such as not only general display devices but also backlight devices, signal lamps, advertisements, and automobiles for lighting devices and LCD displays. Recently, as the luminance problem, which was the limitation of LED, has been greatly improved, the advantages of long life and low power usage are highlighted, making it the next generation light source in the optical semiconductor era led by compound semiconductors of the 21st century.

When the voltage is applied between the p-electrode and the n-electrode of the light emitting device in the external circuit, holes and electrons are injected into the p-electrode and the n-electrode. Is converted to output. The light output direction varies depending on the structure in which the light emitting device is bonded to the substrate. For example, when a reflective material is formed on the light output p-electrode and the light emitting element is flip chip bonded to the substrate, light is emitted to the outside through the transparent substrate, the transparent electrode is formed on the p-electrode, and the light emitting element is formed on the substrate. When normal bonded, light is emitted to the outside through the p-electrode.

The light emitting element is bonded to the substrate and the p-electrode and n-electrode of the LED are connected to an external lead electrode formed in a package or a sub-mount with a metal wire, and when a white light source is produced, the phosphor is sealed in a sealing material such as plastic, glass, or epoxy resin. By mixing and fixing the LED is completed.

LEDs can be applied to all fields requiring light, and are particularly active in backlight devices of mobile communication devices because they generate light with high efficiency at low voltage. Since mobile communication devices must be easy to carry while on the move, they need to be miniaturized and made thinner and thinner.

Therefore, the LED module used as a backlight light source should be thin in the width direction to satisfy the miniaturization and slimming conditions of the device. LED modules are becoming smaller and smaller according to the trend of miniaturization and slimming of devices, and LEDs are also manufactured in a surface mount device (SMD) type to be directly mounted on a printed circuit board (PCB). SMD type LED modules are manufactured in top view and side view types according to their purpose of use, and the side type LED modules will be described.

1 is a perspective view showing the structure of a conventional side-type LED module, the plastic body 101, the lead electrodes (120a, 102b) for applying an external power source, the LED 103 for outputting light when power is applied, and static electricity Or a zener diode 104 to protect the LED 103 from reverse voltage, and conductive wires 105a and 105b to electrically connect the LED 103 and the zener diode 104 to the respective lead electrodes 120a and 102b. 105c).

FIG. 2 is a cross-sectional view illustrating the module structure of FIG. 1 in detail. The plastic body may have a separate reflective film or may manufacture the plastic body itself in white to efficiently reflect the light of the LED 203 formed therein. . In addition, when the reverse current is applied by the static electricity and the reverse voltage in addition to the LED 203, the zener diode 204 may be disposed together to bypass the reverse current to prevent damage to the LED 203. At this time, the zener diode 204 is connected in parallel to the same electrode as the LED 203, the wire bonding technique using a conductive wire is generally used.

The side type LED module bonds the plastic body 201 and the printed circuit board (not shown) with an adhesive, and electrically connects the electrode wiring of the printed circuit board and the lead electrodes 202a and 202b of the plastic body to communicate with each other. Used as a backlight element of the device.

In this LED module structure, one electrode of the LED 203 is electrically and physically bonded to the electrode of the substrate, and the other electrode is connected to an external electrode by bonding the wire 205 to the substrate to which the LED 203 is bonded. Bonding to the plastic body 201, the resulting combination must be bonded back to the printed circuit board to be applied to the actual LED module, so the number of parts and the work process is increased to increase the manufacturing cost. In addition, the plastic body 201 is formed by a plastic injection process, plastic injection has a limitation in slimming, which causes a problem that the size of the LED module increases.

In addition, when the wire 205 is bonded to connect the LED 203 and the zener diode 204 located inside the plastic body 201 to the external electrodes, the plastic body may be formed due to its structural position and the narrow plastic body. There is a problem in that the LED 203 is placed inside the 201 and the wire 205 cannot be bonded, but the wire 205 is bonded to the outside and then bonded to the plastic body 201.

Accordingly, the present invention has been made in view of the above problems, by using a metal plating process on the insulating substrate to form a high reflective structure and bonding the light emitting device on the insulating substrate to slim the module, simplifying assembly It is an object of the present invention to provide an optical module and a method of manufacturing the same.

The present invention for achieving the above object, the substrate formed with a plurality of external extension electrodes; A light emitting device electrically connected to the electrodes; And a metal structure formed to surround the light emitting device and formed above the height of the light emitting device.

In addition, the present invention comprises the steps of forming a plurality of electrodes on the substrate; Forming an insulating layer on the entire surface of the substrate and patterning the exposed portion of the plurality of electrodes; Forming a metal structure based on a plating method on the insulating layer to surround the exposed plurality of electrodes; And electrically bonding a light emitting device to the exposed plurality of electrodes.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

According to an embodiment of the present invention, the electrode wiring is formed on the insulating substrate and the metal structure is formed high so that the metal structure can be used as the reflective film and the lead electrode, the light emitting device is physically bonded on the substrate, and the p- The structure of the optical module which wire-bonded the electrode and n-electrode to the electrode wiring is demonstrated.

3A is a cross-sectional view illustrating a structure of an optical module according to an exemplary embodiment of the present invention. As shown in FIG. 3A, a p-electrode and an n-electrode of the light emitting device 100 may be formed on an insulating substrate 200 capable of semiconductor processing. An electrode wiring 210 is formed, and an insulating layer 220 is formed thereon to electrically insulate other portions from the electrode wiring 210, which is a contact between the wire 240 bonding and the lead electrode 270. It is patterned to expose. The metal structure formed by the plating frame forms the reflective film 230 and the lead electrode 270. The reflective film 230 is incident on the light guide plate without emitting the light of the side light emitting device 100 to the outside, and the light emitting device 100 is bonded to the insulating layer 220 in the reflective film 230 to form the insulating substrate 200. The wire 240 is bonded to the electrode wiring 210 of the wire electrode 270, and the lead electrode 270 is connected to an external power source.

That is, as can be seen through the above structure, the present invention is formed on the insulating substrate 200 capable of a semiconductor process by using a metal plating process to form a metal plating layer on the outside of the mounting portion of the light emitting device 100, the light of the light emitting device 100 Incident to the light guide plate is a first feature.

In addition, the second feature is to form a lead electrode 270 for supplying external power to the light emitting device 100 by patterning a metal plating layer on a side of the reflective film 230 of the light emitting device 100. In this case, the electrode wiring 210 of the insulating substrate 200 may be extended to form the lead electrode without forming the lead electrode 270. In addition, a zener diode is connected to the lead electrode to bypass the static electricity and the reverse voltage to protect the light emitting device 100.

3B is a cross-sectional view illustrating a structure of an optical module according to an exemplary embodiment of the present invention. As shown therein, the light emitting device 100 is bonded to the inside of the frame of the reflective film 230 and p− of the light emitting device 100 is bonded. A wire 240 is bonded to the electrode wire 210 of the insulating substrate 200 and the lead electrode 270 is formed on the electrode wire 210 positioned on the side of the reflective film 230.

An optical module according to an embodiment shown in FIG. 3 will now be described in detail according to a semiconductor process procedure. Here, the manufacturing process of the optical module using the side type LED as a light emitting device is shown.

First, the electrode wirings 210 of the anode and the cathode corresponding to the p-electrode and the n-electrode of the LED 100 are patterned on the insulating substrate 200 capable of semiconductor processing.

Since the other portion of the electrode wiring 210 should be electrically insulated, one end surface of the electrode wiring 210 for depositing the insulating layer 220, bonding the electrode of the LED 100 to the conductive wire 240, and the optical module The insulating layer 220 of the bias applying region electrically connecting the external circuit is patterned to be removed.

The next step of patterning the insulating layer 220 is to perform a plating process for configuring the reflective film structure 230 and the lead electrode 270 for extending the electrode of the light emitting device to an external circuit. In the plating process, the seed metal is formed and the plating mold is formed, followed by plating or plating using an electroless plating method. The plating process forms a metal structure higher than the height of the LED 100 to reflect the side light of the LED 100 and to protect the LED 100.

After the plating process is performed to form the reflective film 230 and the lead electrode 270, the LED 100 is bonded to the insulating layer 220 inside the reflective film 230. As a method of bonding the LED 100 to the insulating layer 220, a paste is applied between the substrate portion of the LED 100 and the insulating layer 220 to be die-bonded.

The two electrodes of the LED 100 and the electrode wiring 210 inside the reflective film 230 are bonded to each other using the conductive wire 240. In another embodiment, two electrodes of the LED 100 and the electrode wiring 210 are aligned to face each other, and two electrodes or the electrode wiring 210 of the LED 100 having the flip chip bonding junction are formed on one of the solders 260. Use pressure and heat to join.

4 is a cross-sectional / plan view showing a flip chip bonding structure of the light emitting device of FIG. 3, and as shown therein, the electrode wiring 210 inside the reflective film 230 extends to the lower end of the LED 100 to display the LED 100. The bottom of) and the top of the electrode wiring 210 is shown bonded by the conductive bonding metal 260. The flip chip bonding method bonds heat and pressure or only pressure by using the conductive bonding metal 260. Here, a conductive metal is used as solder metal, solder, or gold (Au) stud bump or plated bump.

When the light emitting device 100 is bonded and a device such as a zener diode or a thin film resistor is bonded to the optical module to generate a white light source, the inside of the reflective film in which the light emitting device is bonded by mixing phosphors in a sealing material such as plastic, glass, or epoxy resin ( The optical module is completed by fixing to 250). In addition, the lens sheet for controlling the distribution of light emitted from the light emitting device is integrated in the inside of the reflective film 250 to complete the optical module.

The manufacturing process of the optical module as described above is a method of manufacturing an LED module using an insulating substrate, so that a zener diode cannot be integrated into the insulating substrate, the zener diode for complementing the withstand voltage characteristics of the LED must be bonded with an off chip.

In the manufacturing process of the optical module, a structure in which a Zener diode is integrated in a silicon substrate and connected in parallel to the LED using a silicon substrate without using an insulating substrate is described.

FIG. 5 is a cross-sectional / plan view showing a structure in which a zener diode is connected in parallel to the optical module of FIG. 3 in a semiconductor process, and as shown in FIG. 3, a predetermined zener diode as a constant voltage device is formed on the silicon substrate 300. Selective diffusion 310 is performed in the region to form a constant voltage device, and the insulating layer 320 is deposited and patterned to etch the insulating layer 320 of a portion of the diffusion layer 310 of the constant voltage device to form a contact hole. And the electrode wirings are formed by a lift-off or metal etching process. Formation of the electrode wiring The following process is the same as the optical module manufacturing process of FIG. 3, and the optical module in which the constant voltage element is integrated is completed by forming the reflective film 350 and the lead electrode 390 by performing the plating process and the LED bonding.

In this case, the method of manufacturing a constant voltage device uses a general method of manufacturing a zener diode. The Zener diode fabrication method forms an impurity diffusion mask material such as a silicon oxide film on the entire surface of the substrate, and patterns the mask and diffuses the impurities at a high concentration to selectively diffuse the p-type or n-type impurities into the substrate. In order to form impurities other than the previously formed impurities, the diffusion mask is formed again and the impurities are diffused to form a p-n diode.

The optical module integrating the constant voltage device has a structure in which two electrodes of the LED 100 and the electrode wiring 330 inside the reflective film 350 are bonded using the conductive wire 360. In another embodiment, the two electrodes of the LED 100 and the electrode wiring 330 may be aligned to face each other, and may be bonded by applying pressure and heat using solder formed on the LED 100 or the electrode wiring 330.

FIG. 6 is a cross-sectional / plan view showing a flip chip bonding structure of the light emitting device of FIG. 5. As shown in FIG. 6, an electrode wiring 330 is formed on a silicon substrate 300 in which a constant voltage device is integrated, and a reflective film 350 is formed. The inner electrode wiring 330 extends to the lower end of the LED 100 so that the lower end of the LED 100 and the upper end of the electrode wiring 330 are joined by the conductive bonding metal 380. Here, the conductive bonding metal 380 uses a solder metal, solder, or gold (Au) stud bump or plated bump.

When the light emitting device 100 is bonded in the optical module in which the constant voltage device is integrated, and a device such as a zener diode or a thin film resistor is bonded to the optical module to generate a white light source, phosphors are applied to a sealing material such as plastic, glass, and epoxy resin. The optical module is completed by mixing and fixing the light emitting device 100 to the inside of the reflective film 370 bonded to each other.

The manufacturing process of the optical module as described above is a method of manufacturing an LED module using a silicon substrate to increase the breakdown voltage characteristics of the LED by integrating a zener diode on the silicon substrate.

As described in detail above, the present invention has an effect of miniaturizing and slimming a backlight element used in a mobile communication terminal, a display device, etc. by applying a metal plating process to a silicon substrate or an insulating substrate, thereby miniaturizing and slimming an optical module. .

In addition, when a silicon substrate is used, semiconductor electronic devices such as a constant voltage device or a thin film resistor may be integrated to improve the breakdown voltage characteristics of the light emitting device bonded to the optical module.

In addition, there is an effect of reducing the number of components constituting the optical module by simplifying the manufacturing process by flip chip bonding and bonding the light emitting device to the electrode wiring of the substrate to reduce the manufacturing cost.

Claims (11)

A substrate on which a plurality of external extension electrodes are formed; A light emitting device electrically connected to the electrodes; And And a metal structure formed to surround the light emitting device and formed above the height of the light emitting device. The method of claim 1, wherein the metal structure, The optical module is configured to be electrically connected to the electrode wiring at an end of the electrode wiring, and to be electrically connected to an external circuit. The method of claim 1, wherein the light emitting device, The optical module is connected via the electrode wiring and the conductive wire bonding. The method of claim 1, wherein the light emitting device, Connected via electrode wiring and conductive bonding metal, The connection of the light emitting element and the electrode wiring through the conductive bonding metal is made by applying only heat and pressure or pressure. The method of claim 1, And a constant voltage device integrated in the substrate and connected in parallel to an electrode connected to the light emitting device. Forming a plurality of electrodes on the substrate; Forming an insulating layer on the entire surface of the substrate and patterning the exposed portion of the plurality of electrodes; Forming a metal structure based on a plating method on the insulating layer to surround the exposed plurality of electrodes; And And electrically bonding a light emitting device to the exposed plurality of electrodes. The method of claim 6, Before forming the plurality of electrodes on the substrate, further comprising forming a constant voltage device by implanting impurities into the substrate; And said constant voltage device is connected to said plurality of electrodes. The method of claim 6, wherein the forming of the metal structure, Forming a metal mold, and forming the metal structure on the plated metal mold based on a metal plating process or plating the metal mold based on an electroless plating method. The method of claim 6, wherein the bonding step of the light emitting device And bonding two electrodes of the light emitting device to exposed electrodes on the substrate, respectively, by wire bonding or flip chip bonding. The method of claim 6, wherein the bonding step of the light emitting device The method of manufacturing an optical module, characterized in that it further comprises the step of filling the phosphor or silicon gel or epoxy around the light emitting device. The method of claim 10, wherein the bonding step of the light emitting device And forming a lens sheet on the light emitting element.

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