KR101366268B1 - Light emitting device package and submount and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a light emitting device package, a submount, and a manufacturing method thereof, and more particularly, to a light emitting device package and a submount thereof capable of improving reliability. The present invention provides a light emitting device package comprising: a substrate having a light emitting device mounting portion; At least a pair of electrodes formed by connecting a mounting portion of the substrate and a lower portion of the substrate; It is preferably configured to include a shot preventing groove formed in at least a portion of the lower end of the edge portion of the substrate.

Light emitting device, package, short, LED, through hole.

Description

Light emitting device package and submount and manufacturing method thereof {Package and sub-mount for light emitting device and method for making the same}

The present invention relates to a light emitting device package, a submount, and a method for manufacturing the same, and more particularly, to a light emitting device package, a submount, and a method for manufacturing the same, which can improve reliability.

Light emitting diodes (LEDs) are well-known semiconductor light emitting devices that convert current into light. In 1962, red LEDs using GaAsP compound semiconductors were commercialized. GaP: N series green LEDs and information communication devices As a light source for a display image of an electronic device.

The wavelength of the light emitted by these LEDs depends on the semiconductor material used to fabricate the LED. This is because the wavelength of the emitted light depends on the band gap of the semiconductor material, which represents the energy difference between the valence band electrons and the conduction band electrons.

Gallium nitride compound semiconductors (Gallium Nitride: GaN) have attracted much attention in the field of high power electronics development due to high thermal stability and wide bandgap (0.8 to 6.2 eV). One reason for this is that GaN can be combined with other elements (indium (In), aluminum (Al), etc.) to produce semiconductor layers that emit green, blue and white light.

Recently, as the luminance problem, which is a limitation of LEDs, has been greatly improved, application fields such as backlights, camera flashes, automobiles, electronic signs, traffic signals, lighting LEDs, etc. have been greatly expanded throughout the industry.

In particular, LEDs for LCD backlight units, which have small size and high brightness, are expected to increase in use as they replace CCFL lamps, which have been used as light sources of conventional backlight units.

An example of such a package of LEDs is an LED 20 connected to a sub-mount 10 in which a mounting groove 11 is formed, as shown in FIG. 1, and the submount 10 is connected to the sub-mount 10. The metal wiring is coupled to the formed PCB substrate 30.

2 is a cross-sectional view taken along line AA ′ of FIG. 1, and as shown, the submount 10 includes a mounting groove 12 and a through hole through which the LED 20 is to be mounted on the substrate 11. holes 13 are formed, and the electrode wirings 14a and 14b are formed on the substrate 11 of the submount 10 to be connected to the front and rear surfaces of the substrate 10 through the through holes 13. An insulation layer 15 for electrical insulation is formed between the 11 and the electrode wirings 14a and 14b.

The above-described submount 10 is manufactured at a wafer level using a semiconductor process, separated into individual submounts 10 in a package unit by a dicing process, and then formed on the rear side of the electrode wiring 14b. ) And the metal wiring 21 of the PCB substrate 20 are bonded using a cream solder or a conductive epoxy 22. In this bonding process, the solder or epoxy 22 is exposed to the submount by a dicing process. The substrate 11 may be in contact with the surface a of the substrate 11 to be electrically connected to the metal wires 14a and 14b to cause a defect.

In order to solve this problem, the distance w between the electrode wiring 14b formed on the rear surface of the submount 10 and the surface a of the substrate 11 exposed by the dicing process is sufficiently longer than the solder spreading area. Although the above-mentioned problem may be solved, in this case, the size of the individual submount 10 is increased, so it is not suitable for manufacturing a small package, and the manufacturing cost due to the decrease in the amount of production of the individual submounts per wafer may be greatly increased.

SUMMARY OF THE INVENTION The present invention provides a light emitting device package, a submount, and a method of manufacturing the same, which may improve a defect caused by solder or epoxy contacting exposed surfaces of a package and a submount during a bonding process of the light emitting device. There is.

As a first aspect of the present invention, there is provided a light emitting device package comprising: a substrate having a light emitting device mounting portion; At least a pair of electrodes formed by connecting a mounting portion of the substrate and a lower portion of the substrate; It is preferably configured to include a shot preventing groove formed in at least a portion of the lower end of the edge portion of the substrate.

The short prevention groove may be located at least at a portion where the electrode is formed, and may be formed along an edge of the substrate.

At this time, the height or depth of the shot preventing groove is preferably 50 to 500㎛.

An insulating layer may be formed on at least a portion between the substrate and the electrode.

The shape of the short prevention groove may be formed by projecting an area narrower than the entire area of the substrate from the lower side of the substrate.

As a second aspect for achieving the above technical problem, the present invention provides a light emitting device submount, comprising: a substrate provided with a light emitting element mounting portion; At least a pair of electrodes formed by connecting a mounting portion of the substrate and a lower portion of the substrate; It is preferably configured to include a shot preventing groove formed in at least a portion of the lower end of the edge portion of the substrate.

As a third aspect for achieving the above technical problem, the present invention provides a method of manufacturing a light emitting device package, the first step of forming a light emitting device mounting portion on the first surface of the substrate; A second step of forming a through hole penetrating the first and second surfaces of the substrate; A third step of forming a short prevention groove along an edge of the second surface of the substrate; It is preferably configured to include a fourth step of forming at least a pair of electrodes on the substrate.

In this case, at least two or more steps of the first, second, and third steps may be simultaneously performed, and at least one of the first, second, and third steps may be wet etching or dry etching. The laser drilling may be performed by any one method.

The present invention provides a submount and a package having a short prevention groove surrounding a rear electrode, thereby providing a submount surface in which a solder or epoxy is exposed by a dicing process in a bonding process between an individual submount in a package unit and a PCB substrate. It is effective in maximizing the production efficiency by greatly improving the defect caused by the electrical contact with the metal wiring of the PCB by contact.

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

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. Rather, the intention is not to limit the invention to the particular forms disclosed, but rather, the invention includes all modifications, equivalents and substitutions that are consistent with the spirit of the invention as defined by the claims.

Like reference numerals designate like elements throughout the description of the drawings. The dimensions of the layers and regions in the figures are exaggerated for clarity. In addition, each embodiment described herein includes an embodiment of a complementary conductivity type.

It will be appreciated that when an element such as a layer, region or substrate is referred to as being present on another element "on," it may be directly on the other element or there may be an intermediate element in between . If a part of a component, such as a surface, is expressed as 'inner', it will be understood that this means that it is farther from the outside of the device than other parts of the element.

Further, relative terms such as " beneath " or " overlies " are used herein to refer to a layer or region relative to a substrate or reference layer, Can be used to illustrate.

It will be understood that these terms are intended to include other directions of the device in addition to the direction depicted in the figures. Finally, the term 'directly' means that there are no intervening elements in the middle. As used herein, the term 'and / or' includes any and all combinations of one or more of the recorded related items.

Although the terms first, second, etc. may be used to describe various elements, components, regions, layers, and / or regions, such elements, components, regions, layers, and / or regions It will be understood that it should not be limited by these terms.

These terms are only used to distinguish one element, component, region, layer or region from another region, layer or region. Thus, the first region, layer or region discussed below may be referred to as a second region, layer or region.

As shown in FIG. 3 and FIG. 4, the submount 100 is formed of a substrate 110 having a light emitting device mounting portion 120, and the mounting portion 120 and the substrate 110 of the substrate 110 are provided. At least one pair of electrodes 130 and 131 formed by connecting the lower part is formed.

The electrodes 130 and 131 may include a front electrode 130 formed on the front surface of the substrate 110 and a rear electrode 131 formed on the rear surface of the substrate 110. The electrodes 131 are connected to each other through the through holes 150 formed on the substrate 110.

The submount 100 has a short prevention groove 140 formed in at least a portion of the lower end of the edge of the substrate 110, so that the solder used when the above-mentioned back electrode 131 is connected to the PCB is a substrate. It is possible to prevent the phenomenon that the short is in contact with the exposed side of the (110).

The short prevention groove 140 may be formed along the lower surface of the substrate 110 of the submount 100, as shown in FIGS. 3 and 4. That is, as shown in FIG. 3, a narrow portion may be formed inward along the lower side of the substrate 110.

In addition, as shown in FIG. 4, the short prevention groove 140 may be formed to protrude from the lower surface of the substrate 110 to a smaller area than the entire area of the substrate 110.

The short prevention groove 140 may be formed to be inclined with respect to the surface of the substrate 110, and the height and width of the short prevention groove 140 may have a height and a width such that it does not come into contact with the solder during soldering.

≪ Embodiment 1 >

Hereinafter, the manufacturing process of this first embodiment will be described with reference to FIG. 5.

First, the silicon substrate 110 is formed by bulk etching a bath 120 and a through hole 150 on which the light emitting device 200 is to be mounted.

The through hole 150 includes a front side electrode 130 formed on the front surface of the substrate 110 and a back side electrode 131 formed on the back surface of the substrate 110. Can be connected to each other.

Subsequently, in the subsequent process, the solder or epoxy is smeared and exposed by cutting when bonding to a PCB substrate or stem using a cream solder or conductive epoxy by cutting in units of individual submounts 100. The short prevention groove 140 having a predetermined distance w and a height h is formed from the rear electrode 131 so as not to contact the surface.

The short prevention groove 140 is suitable to surround the rear electrode 131 as shown in Figure 4 above, the predetermined distance (w) and height (h) from the rear electrode 131 is 50 About 500 micrometers is suitable.

In addition, the short prevention groove 140 may be formed in the same manner as the through hole 150 forming process or the mounting portion 120 forming process, thereby preventing a separate process or additional cost.

As a bulk etching method for forming the mounting portion 120, the through hole 150, and the shot preventing groove 140 for mounting the light emitting device 200, a wet etching method and a dry etching method may be used. Methods, laser drilling methods, and the like, and may also be formed using two or more of these methods together.

A typical method of the above-described dry etching method is a deep reactive ion etching method.

In the present embodiment shown in FIG. 5, the mounting portion 120 and the through hole 150 are formed using a KOH solution or an anisotropic wet etching solution such as TMAH or EDP using the [100] orientation single crystal silicon substrate 110. And a short prevention groove 140.

In this way, when the wet etching is performed, the mounting part 120 having the inclined surface of 54.74 degrees is formed. The width and depth of the mounting part 120 for mounting the light emitting device 200 may vary depending on the size or thickness of the light emitting device 200. The light emitted from the side of the light emitting device 200 may be used as efficiently as possible.

A wet etching method for forming the mounting part 120, the through hole 150, and the short prevention groove 140 for mounting the light emitting device 200 is as follows.

First, as described above, after mask-patterning the mounting portion 120 for mounting the light emitting device 200 and the region where the through hole 150 and the short prevention groove 140 are to be formed, the mounting of the light emitting device 200 may be performed at the same time. The mounting part 120, the through hole 150, and the shot preventing groove 140 are wet etched.

Second, after mask patterning only one of the mounting portion 120 for mounting the light emitting device 200, the through-hole 150 and the short prevention groove 140, the first etching proceeds to the remaining portion By patterning and etching secondarily, there is a method of controlling the depth ratio of the mounting portion 120 for mounting the light emitting device 200 and the depth ratio of the through hole 150 and the short prevention groove 140.

In addition, the formation of the through-hole 150 and the shot preventing groove 140 is uniform by etching simultaneously or separately with the mounting area of the light emitting device 200 on the front surface after patterning the mask using an exposure apparatus capable of simultaneously aligning the front and rear surfaces. Allow each other to penetrate at depth.

In addition, when the short prevention groove 140 is formed by a wet etching method, the silicon substrate 110 is excessively etched at a portion where the groove in the x-axis direction and the groove in the y-axis direction cross each other. It is more preferable to apply a compensation pattern for the control (not shown).

Next, an insulation layer 130 for electrical insulation of the substrate 110 is formed on the entire surface of the substrate 110 including the mounting portion 120 and the through hole 150 formed in the substrate 110.

In order to form the insulating layer 130, a silicon oxide film having excellent insulating properties is formed on the entire surface of the substrate 110 by a method such as thermal oxidation.

As an insulating layer forming method other than the above method, a silicon nitride film may be deposited by the LPCVD method, the PECVD method, or the like to be used as the insulating layer 130.

The insulating layer 130 may be omitted when an insulator such as aluminum nitride (AlN) or aluminum oxide (AlO _x ) is used as the substrate 110.

As such, in the state where the insulating layer 130 is formed on the substrate 110 on which the mounting unit 120 and the through hole 150 are formed, the electrode including the front electrode 130 and the rear electrode 131 is patterned. To form.

The front electrode 130 and the rear electrode 131 are connected to each other through the through hole 150.

The following three methods may be used to form the electrodes 130 and 131.

First is the method by electroplating.

First, as described above, after the mounting portion 120 and the through hole 150 of the light emitting device 200 are formed, the bonded metal is formed on both sides of the back and front surfaces of the substrate 110 of the three-dimensional structure in which the insulating layer 130 is formed. E).

Electrodes including the front electrode 130 and the rear electrode 131 are formed on the bonding metal by electroplating or electroless plating.

Thereafter, a photoresist is coated, exposed, and developed to etch the electrodes 130 and 131 to be separated from each other by a positive electrode and a negative electrode. Form an electrode as shown in 5.

In addition, after the photoresist is patterned before forming the electrodes 130 and 131, and after forming the electrodes 130 and 131 by the plating method, the photoresist is removed and the bonding metal (not shown) is etched to form both electrodes and The electrodes may be formed by separating the negative electrodes from each other.

Second, it is a method by lift-off.

First, photoresist is applied to both surfaces of the front and rear surfaces of the substrate 110, and exposed and developed to separate the positive electrode and the negative electrode from each other.

Subsequently, the metals 130 and 131 are deposited on the front, rear, and through holes by a sputtering method or an e-beam evaporation method, and then lifted off the applied photoresist. It will be in the same state as in FIG. 5.

In addition to such a structure, in order to increase the thickness of the electrodes 130 and 131, a metal layer may be formed by electroplating or electroless plating to supplement the layers of the electrodes 130 and 131.

Third, lift-off and electroplating mixing methods.

First, the front electrode 130 or the rear electrode 131 is formed on the front or rear surface of the substrate 110 by the above lift-off method.

The electrode is formed on the opposite surface of the electrode formed by the lift-off method by electroplating or electroless plating, and the front electrode 130 and the rear electrode 131 thus formed are electrically connected through the through-holes. It is.

The metals for forming the electrodes 130 and 131 should not only have excellent electrical properties but also excellent adhesion to the insulating layer, and generally have excellent adhesion to silicon oxide film and titanium (Ti) and chromium ( Cr), tantalum (Ta), or the like may be used as the adhesion layer.

In addition, gold (Au), copper (Cu), and aluminum (Al), which are representative materials as electrodes that are excellent in electrical characteristics and can be easily deposited in a semiconductor process, may be used.

At this time, the metal for forming the electrode is exposed to high temperatures when joining the components of the module during the post-process, since the adhesion layer (Tihe or Cr) is diffused into Au (diffusion) to reduce the electrical properties of Au, To prevent this, a diffusion barrier layer such as platinum (Pt) or nickel (Ni) may be used between the adhesive layer of Ti and Cr and Au.

Accordingly, the structures of the electrodes 130 and 131 may form Ti / Pt / Au or Cr / Ni / Au and Cr / Cu / Ni / Au structures.

In order to form the electrodes 130 and 131 by the electroplating method, a coupling metal (not shown) may be required, and the coupling metal should have excellent electrical characteristics such as the metal for the electrodes 130 and 131. In addition, the insulating layer 130 and the adhesion should be excellent.

Therefore, titanium (Ti), chromium (Cr), tantalum (Ta), etc. are used as an adhesion layer, and gold (Au), copper (Cu), and aluminum (Al) are used as bonding metals to form Cr / Au. B, Cr / Cu, Ti / Au, Ta / Cu, Ta / Ti / Cu can be formed.

In this case, the electrodes 130 and 131 may be formed to have a structure including Cr / Cu / Cu / Ni / Au or Cr / Au / Au, Cr / Au / Cu / Ni / Au, and the like, including the bonding metal.

Next, in order to improve the efficiency of light emitted from the light emitting device 200, a reflective layer (not shown) may be formed on the bottom surface and the inclined surface of the mounting portion 120 of the light emitting device.

As the reflective film material, aluminum (Al) or silver (Ag) having excellent reflectivity may be used. In addition, the reflective film is formed by coating a photoresist on the entire surface, and exposing and developing the pattern to expose the bottom surface or the inclined surface on which the light emitting device is mounted, and depositing a metal layer for the reflective film by a sputtering method or an E-beam deposition method. It can be formed by lifting off.

In addition, a reflective film may be formed by depositing a reflective film layer on the entire surface and etching unnecessary portions after patterning.

At this time, the metal constituting the reflective film is formed so as not to be connected to or overlapped with the positive electrode and the negative electrode of the electrodes 130 and 131 at the same time so as not to be electrically shorted, and to be bonded to the electrode metal of the light emitting device. More preferably, the reflective film metal is not formed in the region where the solder or the Au stud 210 is formed.

Next, the light emitting device 200 is electrically connected to the front electrode 130 by a method such as bonding using a conductive solder or Au stud 210, and then phosphor or silicon A filler (not shown) for filling the mounting unit 120 on which the light emitting device 200 is mounted may be formed of a material such as a gel or a light transmitting epoxy.

The process may fill the filler of the light emitting device 200 after cutting the substrate 110 in a package unit or a submount 100 unit, or bonding the light emitting device 200 to the substrate 110. After filling the filler, the substrate 110 may be cut and packaged in a package unit.

As the solder material for bonding the light emitting device 200, gold tin (AuSn), red tin (PbSn), indium (In), or the like may be formed by an E-beam deposition method.

Subsequently, a submount 100 substrate having a lens sheet (not shown) having a designed shape in order to control the distribution of light emitted from the light emitting device 200 and bonded to the light emitting device 200 as necessary. It can also be bonded to (110) and cut into unit packaging units for use.

Next, the cream solder or conductive epoxy 320 is formed on the PCB substrate 300 on which the electrode mount 310 for supplying power to the light emitting device 200 is formed on the submount 100 cut in the above-described packaging unit as shown in FIG. 6. By bonding using a light emitting device 200 for various purposes it can be manufactured.

≪ Embodiment 2 >

Hereinafter, a second embodiment will be described with reference to FIG. 7. Portions not described below may be the same as the first embodiment.

As illustrated in FIG. 7, a mounting portion 120 on which the light emitting device 200 is mounted on the silicon substrate 110 is formed by wet etching a predetermined depth on the entire surface of the substrate 110.

In addition, a through hole for connecting the front side electrode 130 formed on the front surface of the substrate 110 and the back side electrode 131 formed on the rear surface of the substrate 110; 151 is formed by a dry etching method.

Meanwhile, when bonding to a PCB substrate or stem using a cream solder or conductive epoxy by cutting into individual submount units, such solder or epoxy is smeared to contact the exposed surface of the substrate 110 by cutting. The short prevention groove 141 having a predetermined depth and height from the rear electrode 131 is formed using a dry etching method.

The formation of the through hole 151 and the formation of the short prevention groove 141 may be performed at the same time. In this case, the dry etching method may use a deep reactive ion etching method.

In addition, the formation of the mounting portion 120, the through hole 151, and the shot preventing groove 141 may be made by a laser drilling method in addition to the wet etching method and the dry etching method.

The process of forming the front electrode 130 and the rear electrode 131 may be the same as in the first embodiment.

Third Embodiment

Hereinafter, a third embodiment will be described with reference to FIG. 8. Portions not described below may be the same as in the previous embodiment.

After forming the mounting portion 120 and the through-hole 152 by wet etching for mounting the light emitting device 200, the short prevention groove 142 is formed on the back of the substrate 110 by a laser drilling method or a dry etching method. You may.

However, in this case, since a separate process is required, the manufacturing cost of the light emitting device package may increase.

Therefore, in forming the through hole 152, the through hole for the positive electrode and the through hole for the negative electrode may be separated.

In addition, an etching process for forming the mounting portion 120, the through hole 152, and the shot preventing groove 142 may include forming a mask layer (not shown) to distinguish between portions to be etched and portions to be protected from etching. In this case, the mask layer to be used should be a material that can be used as a mask for a long time when etching, and generally a silicon nitride film or a silicon oxide film may be used.

As described above, the present invention provides a submount and a package having a short prevention groove surrounding a rear electrode, whereby solder or epoxy is exposed by a dicing process in a bonding process between an individual submount of a package unit and a PCB substrate. By contacting the surface of the submount and electrically connected to the metallization of the PCB substrate greatly improves the defect caused by maximizing production efficiency.

The above embodiment is an example for explaining the technical idea of the present invention in detail, and the present invention is not limited to the above embodiment, various modifications are possible, and various embodiments of the technical idea are all protected by the present invention. It belongs to the scope.

1 is a cross-sectional view showing an example of a general light emitting device package.

FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG. 1.

3 is a perspective view of the present invention.

4 is a rear view of the present invention.

5 and 6 are cross-sectional views showing a first embodiment of the present invention.

7 is a cross-sectional view showing a second embodiment of the present invention.

8 is a sectional view showing a third embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

100: submount 110: substrate

120: mounting portion 130: front electrode

131: rear electrode 140: short prevention groove

150 through hole 200 light emitting element

300: PCB Board

Claims (10)

In the light emitting device package, A substrate having a light emitting element mounting portion; At least a pair of electrodes formed by connecting a mounting portion of the substrate and a lower portion of the substrate; And a short prevention groove formed in at least a portion of the portion proximate to the electrode at the lower end of the edge of the substrate. The light emitting device package according to claim 1, wherein the short prevention groove is located at least in a portion where the electrode is formed. The light emitting device package according to claim 1, wherein the short prevention groove is formed along an edge of a lower end of the substrate. The light emitting device package according to claim 1, wherein the height or depth of the short prevention groove is 50 to 500 µm. The light emitting device package of claim 1, wherein an insulating layer is formed on at least a portion between the substrate and the electrode. The light emitting device package according to claim 1, wherein the short prevention groove is formed by protruding an area smaller than the entire area of the substrate from the lower side of the substrate. In the submount for a light emitting element, A substrate having a light emitting element mounting portion; At least a pair of electrodes formed by connecting a mounting portion of the substrate and a lower portion of the substrate; And a short prevention groove formed in at least a portion of the portion adjacent to the electrode at the lower end of the edge of the substrate. In the manufacturing method of the light emitting device package, Forming a light emitting element mounting portion on the first surface of the substrate; A second step of forming a through hole penetrating the first and second surfaces of the substrate; A third step of forming a short prevention groove in at least a portion of the portion close to the portion where the electrode at the lower end of the edge of the second surface of the substrate is to be formed; And a fourth step of forming at least one pair of electrodes on the substrate. The method of claim 8, wherein at least two or more of the first, second, and third steps are performed at the same time. The method of claim 9, wherein at least one of the first, second, and third steps is performed by any one of wet etching, dry etching, and laser drilling. .

Images