KR102022460B1 - Semiconductor light emitting device and method of manufacturing the same - Google Patents

Abstract

Disclosed is a semiconductor light emitting device comprising: a semiconductor light emitting device chip including a plurality of semiconductor layers including an active layer for generating light by recombination of electrons and holes, and electrodes electrically connected to the plurality of semiconductor layers; An encapsulant formed to enclose a semiconductor light emitting device chip; A lens encapsulant made of a transparent thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm; And an external substrate including a conductive layer electrically connected to an electrode of the semiconductor light emitting device chip, wherein the encapsulant is for a semiconductor light emitting device in which a front surface of the semiconductor light emitting device is exposed to the outside except for a lower surface contacting the external substrate.

Description

Semiconductor Light-Emitting Device and Manufacturing Method Thereof {SEMICONDUCTOR LIGHT EMITTING DEVICE AND METHOD OF MANUFACTURING THE SAME}

The present disclosure relates generally to a semiconductor light emitting device and a method of manufacturing the same, and more particularly, to a semiconductor light emitting device and a method of manufacturing the same having improved light extraction efficiency.

This section provides background information related to the present disclosure which is not necessarily prior art. In addition, in the present specification, direction indications such as up / down, up / down, etc. are based on the drawings.

1 is a view showing an example of a conventional semiconductor light emitting device chip.

The semiconductor light emitting device chip may include a growth substrate 300 (eg, a sapphire substrate), a growth layer 300, a buffer layer 310, a first semiconductor layer 320 having a first conductivity (eg, an n-type GaN layer), and electrons. The active layer 330 (eg, INGaN / (In) GaN MQWs) that generates light through recombination of holes, and the second semiconductor layer 340 (eg, p-type GaN layer) having a second conductivity different from the first conductivity are sequentially And a transmissive conductive film 350 for spreading current and an electrode 360 serving as a bonding pad, and serving as a bonding pad on the etched and exposed first semiconductor layer 320. An electrode 370 (for example, a Cr / Ni / Au laminated metal pad) is formed. The semiconductor light emitting device of the form as shown in FIG. 1 is particularly called a lateral chip. Here, the growth substrate 300 is the mounting surface when the side is electrically connected to the outside. In the present specification, an externally connected semiconductor light emitting device chip or semiconductor light emitting device means a printed circuit board (PCB), a submount, a thin film transistor (TFT), or the like.

2 is a view showing another example of the semiconductor light emitting device chip disclosed in US Patent No. 7,262,436. For convenience of description, reference numerals have been changed.

The semiconductor light emitting device chip includes a growth substrate 300 and a growth substrate 300, a first semiconductor layer 320 having a first conductivity, an active layer 330 that generates light through recombination of electrons and holes, and a first conductivity. The second semiconductor layer 340 having a second conductivity different from that of the second semiconductor layer 340 is sequentially deposited, and three electrode layers 380, 381, and 382 are formed to reflect light toward the growth substrate 300. have. The first electrode film 380 may be an Ag reflecting film, the second electrode film 381 may be a Ni diffusion barrier layer, and the third electrode film 382 may be an Au bonding layer. An electrode 370 that functions as a bonding pad is formed on the etched and exposed first semiconductor layer 320. Here, when the electrode film 382 side is electrically connected to the outside, it becomes a mounting surface. A semiconductor light emitting device chip of the same type as that of FIG. 2 is particularly referred to as a flip chip. In the flip chip illustrated in FIG. 2, the electrode 370 formed on the first semiconductor layer 320 is at a lower level than the electrode films 380, 381, and 382 formed on the second semiconductor layer, but may be formed at the same height. You can also do that. The height reference may be the height from the growth substrate 300.

3 is a view showing an example of a conventional semiconductor light emitting device.

The semiconductor light emitting device 400 includes a vertical type light emitting chip 450 in the lead frames 410 and 420, the mold 430, and the cavity 440, and the cavity 440. Is filled with an encapsulant 470 containing a wavelength converting material 460. The lower surface of the vertical semiconductor light emitting device chip 450 is electrically connected directly to the lead frame 410, and the upper surface is electrically connected to the lead frame 420 by a wire 480. A portion of the light emitted from the vertical semiconductor light emitting device chip 450 may excite the wavelength converter 460 to produce light of different colors, and two different lights may be mixed to form white light. For example, the semiconductor light emitting device chip 450 may generate blue light, and light generated by being excited by the wavelength converting material 460 may be yellow light, and blue light and yellow light may be mixed to produce white light. 3 illustrates a semiconductor light emitting device using the vertical semiconductor light emitting device chip 450, but a semiconductor light emitting device having a shape similar to that of FIG. 3 may be manufactured using the semiconductor light emitting device chips illustrated in FIGS. 1 and 2. have.

A semiconductor light emitting device of the type described in FIG. 3 is generally called a semiconductor light emitting device of a package type, and a semiconductor light emitting device having a semiconductor light emitting device chip size is called a semiconductor light emitting device of a chip scale package (CSP) type. Related to the CSP type semiconductor light emitting device is disclosed in Korean Patent Laid-Open No. 2014-0127457. Recently, as the size of semiconductor light emitting devices is reduced, development of CSP type semiconductor light emitting devices has been actively performed.

This will be described later in the section titled 'Details of the Invention.'

This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all, provided that this is a summary of the disclosure. of its features).

According to one aspect of the present disclosure, in a semiconductor light emitting device, a plurality of semiconductor layers including an active layer that generates light by recombination of electrons and holes, and a plurality of semiconductor layers A semiconductor light emitting device chip having an electrode electrically connected to the semiconductor light emitting device chip; An encapsulant formed to enclose a semiconductor light emitting device chip; A lens encapsulant made of a transparent thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm; And an external substrate including a conductive layer electrically connected to an electrode of the semiconductor light emitting device chip, wherein the encapsulant is provided with a semiconductor light emitting device having a front surface exposed to the outside except a bottom surface in contact with the external substrate.

This is described later in the section titled 'Details of the Invention.'

1 is a view showing an example of a conventional semiconductor light emitting device chip;
2 is a view showing another example of the semiconductor light emitting device chip shown in US Patent No. 7,262,436;
3 is a view showing an example of a conventional semiconductor light emitting device;
4 illustrates an example of a semiconductor light emitting device according to the present disclosure;
5 is a view showing a general semiconductor light emitting device to explain the advantages of the semiconductor light emitting device according to the present disclosure;
6 is a view showing an example of a method of manufacturing a semiconductor light emitting device according to the present disclosure;
7 is a view showing an example of a preliminary encapsulant made of a light-transmitting thermoplastic resin according to the present disclosure;
8 is a view showing an example of a method of manufacturing a preliminary encapsulant made of a light-transmitting thermoplastic resin according to the present disclosure;
9 is a view showing an example of a method of manufacturing a preliminary encapsulant made of a translucent thermoplastic resin according to the present disclosure;
10 is a view showing a problem in the case of forming an encapsulant using a conventional transparent liquid transparent thermoplastic resin,
11 is a view showing another example of a method of manufacturing a semiconductor light emitting device according to the present disclosure.

The present disclosure will now be described in detail with reference to the accompanying drawing (s).

4 is a diagram illustrating an example of a semiconductor light emitting device according to the present disclosure. FIG. 4A is a cross-sectional view taken along line AA ′, and FIG. 4B is a top view thereof.

The semiconductor light emitting device 1 includes a semiconductor light emitting device chip 10, an encapsulant 12, and an external substrate 14.

The semiconductor light emitting device chip 10 includes a plurality of semiconductor layers including an active layer 101 that generates light by recombination of electrons and holes, and an electrode 102 electrically connected to the plurality of semiconductor layers. The semiconductor light emitting device chip 10 is preferably a flip chip, and the electrode 102 is exposed from the encapsulant 12. Although the semiconductor light emitting device chip 10 is limited to a flip chip in the present disclosure, the lateral chip or the vertical chip is not excluded. The active layer 101 is exaggerated for clarity, and the active layer 101 is actually thin in a few um.

The encapsulant 12 is formed on the outer substrate 14 to surround the semiconductor light emitting device chip 10. The material of the sealing material 12 consists of a translucent thermoplastic resin. The encapsulant 12 may be formed to have a diameter of up to 2 mm. The translucent thermoplastic resin is preferably a translucent thermoplastic resin having a transmittance of 80% or more for light having a wavelength band of 100 nm to 400 nm. Further preferably, the translucent thermoplastic resin is preferably a translucent thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm.

In the present disclosure, the semiconductor light emitting device chip 10 may emit light having a wavelength band of 100 nm to 400 nm. In addition, the semiconductor light emitting device chip 10 may emit light having a peak wavelength of 300 nm or less. Accordingly, light distribution is smoothly performed by the encapsulant 12 made of a transparent thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm. Extraction efficiency can be improved.

The light-transmissive thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm is preferably a thermoplastic resin having low damage by light having a wavelength band of 100 nm to 400 nm.

The external substrate 14 is not limited as long as it provides a region on which the semiconductor light emitting device chip 10 is mounted. The external substrate 14 may be a substrate for forming a semiconductor light emitting device, and may include, for example, a substrate including lead electrodes, a printed circuit board, a metal plate substrate, and the like.

The external substrate 14 includes a base 141, a conductive layer 142, a prevention layer 143, and a reflective layer 144.

The base 141 may include an insulating material and may also include a material having high thermal conductivity. For example, it may comprise a high thermal conductivity polymer material and / or a ceramic material. In particular, the base 141 may comprise AlN ceramic. Therefore, when the light emitting device is driven, heat generated from the semiconductor light emitting device chip 10 may be effectively discharged to the outside through the base 141.

The conductive layers 142 and 145 are formed on the upper and lower surfaces of the base 141, and the conductive layers 142 formed on the upper surface are electrically connected to the electrodes 102 of the semiconductor light emitting device chip 10. The conductive layer 142 formed on the upper surface and the conductive layer 145 formed on the lower surface are electrically connected, and the semiconductor light emitting device 1 is electrically connected to the outside through the conductive layer 145 formed on the lower surface. For example, as illustrated, the conductive layer 142 formed on the upper surface of the base 141 and the conductive layer 145 formed on the lower surface of the base 141 may be electrically connected to each other through the base 141. The conductive layers 142 and 145 may include an electrically conductive material, and may include, for example, metals such as Ni, Pt, Pd, Rh, W, Ti, Al, Ag, Au, Cu, and the like. Here, the electrode 102 of the semiconductor light emitting device chip 10 may be disposed to face the outer substrate 14 in order to be electrically connected to the conductive layer 142 of the outer substrate 14.

The prevention layer 143 is disposed on the upper surface of the base 141 at a predetermined distance from the conductive layer 142. For example, it may be formed of a metal such as Ni, Pt, Pd, Rh, W, Ti, Al, Ag, Au, Cu, or the like. When the barrier layer 143 is formed of a metal, the barrier layer 143 may be separated from the conductive layer 142 to prevent contact with the conductive layer 142, thereby reducing a short risk.

The prevention layer 143 may be used as a boundary jaw, that is, a dam, to prevent the encapsulant 12 from being formed beyond the prevention layer 143 when the encapsulant 12 is formed, and the prevention layer 143 is omitted. Can be. The prevention layer 143 is preferably a hard material to some extent so as to maintain the shape of the encapsulant 12 protecting the semiconductor light emitting device chip 10, and is preferably selected as an effective material for preventing cracks and cracks.

In contrast, the prevention layer 143 may be formed of a colored reflective material capable of reflecting light emitted from the semiconductor light emitting device chip 10 to the encapsulant 12, but is not limited thereto.

In addition, since the prevention layer 143 is made of a metal material instead of a silicon material, adhesion to the external substrate 14 and the encapsulant 12 may be increased, thereby improving reliability. In addition, since the conductive layer 142 can be formed at the same time, it is possible to shorten the manufacturing process and reduce the manufacturing process time and manufacturing cost.

The prevention layer 143 serves as a dam, but does not prevent the translucent thermoplastic resin forming the encapsulant 12 from flowing out like a wall, but between the upper surface of the barrier layer 143 and the encapsulant 12 when the encapsulant 12 is formed. Since the encapsulant 12 is not formed beyond the barrier layer 143 by the surface tension generated in the encapsulant 12, the encapsulant 12 may be formed so as to cover the entirety or a part of the upper surface of the barrier layer 143. Preferably, the encapsulant 12 is formed at an edge portion where the top surface 1431 and the side surface of the prevention layer 143 meet the side of the prevention layer 143 in the direction of the reflective layer 144 and the top surface 1431 of the prevention layer 143. ) And the encapsulant 12 may cover the entire upper surface 1431 of the protection layer 143 because the surface tension effect generated between the upper surface 1432 and the protection layer 143 is maximized. In particular, the surface tension effect generated between the encapsulant 12 and the upper surface 1431 of the prevention layer 143 is maximized when the angle 1433 formed between the upper surface 1431 and the side surface 1432 of the prevention layer 143 is vertical. . In addition, in order to prevent the encapsulant 12 from flowing out of the prevention layer 143, the prevention layer 143 preferably forms a closed circuit without a gap. The top surface 1431 and the side surface 1432 of the prevention layer 143 are enlarged and illustrated in a circle for better understanding. However, at this time, the inner surface 1434 of the prevention layer 143 is covered by the encapsulant 12, and the outer surface 1432 of the prevention layer 143 is not covered by the encapsulant 12.

The height H1 of the prevention layer 143 is preferably lower than the height of the semiconductor light emitting device chip 10 and is formed to be the same as the height H2 of the conductive layer 142, but is not limited thereto. For example, the height H1 of the prevention layer 143 may be smaller or larger than the height H2 of the conductive layer 142. When the height of the prevention layer 143 is less than or equal to the height of the conductive layer 142 When the directing angle of the light emitted from the semiconductor light emitting device 1 is greater than the height of the conductive layer 142 It can be wider.

The width D1 of the prevention layer 143 is preferably smaller than the width D2 of the conductive layer 142 and smaller than the width D3 of the prevention layer 143 and the conductive layer 142. The width D1 of the prevention layer 143 may be greater than or equal to the width D3 in which the prevention layer 143 and the conductive layer 142 are separated from each other.

The reflective layer 144 is formed on the upper surface of the base 141 and may be formed of a reflective material. For example, it may be made of a metal material such as Al, Ag, Au, and the like. Preferably Au is good. In particular, when the conductive layer 142, the prevention layer 143, and the reflective layer 144 are all formed of Au, three layers may be formed at a time, thereby simplifying the manufacturing process. As a method of forming a metal layer on the base 141, a method such as vapor deposition or plating may be used. However, it is preferable to form Al partially in the conductive layer 142. Here, the reflective layer 144 is a semiconductor in order to overcome the thermal expansion coefficient difference between the reflective layer 144 and the encapsulant 12 or to prevent a short problem between the semiconductor light emitting device chip 10 and the reflective layer 144. The light emitting device chip 10 and the prevention layer 143 are spaced apart from each other.

The reflective layer 144 may improve light extraction efficiency by reflecting light from the semiconductor light emitting device chip 10 toward the external substrate 14 to be directed toward the upper side of the external substrate 14. In particular, when the wavelength band of the light emitted from the semiconductor light emitting device chip 10 is 100nm to 400nm, it is preferable to form the reflective layer 144 with Al having high reflection efficiency.

Meanwhile, the external substrate 14 may further include a heat radiation pad (not shown) disposed on the bottom surface of the base 141. The heat dissipation pad serves to more easily dissipate heat from the outer substrate 14 to the outside.

5 is a view showing a general semiconductor light emitting device to explain the advantages of the semiconductor light emitting device according to the present disclosure.

Referring to FIG. 5A, in the semiconductor light emitting device, a preformed lens L may be attached onto the semiconductor light emitting device chip 10a.

However, the present invention by implementing the lens shape using the encapsulant 12 made of a transparent thermoplastic resin, it is possible to further miniaturize the semiconductor light emitting device without having a separate lens. Particularly, in the case of a transparent thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm among the transparent thermoplastic resins, the solvent is mostly volatilized and the volume is reduced by 90% or more when cured and solidified in a liquid phase. It was difficult to implement a lens-shaped encapsulant 12 using a liquid transparent thermoplastic resin having a transmittance of 90% or more to light. In the present disclosure, a lens-shaped encapsulant 12 formed of a light-transmitting thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm has been solved. Furthermore, by implementing a lens-shaped encapsulant 12 using a light-transmitting thermoplastic resin having a transmittance of 90% or more for light having a wavelength range of 100 nm to 400 nm, the semiconductor light emitting device chip 10 is wrapped around the external substrate 14 while being in contact with the external substrate 14. Except for the lower portion of the encapsulant 12, the encapsulant 12 having the front surface exposed to the outside becomes possible, so that the light exiting the semiconductor semiconductor light emitting device chip 10 and passing through the encapsulant 12 passes through the outer substrate 14. Except for), it was possible to go out in all directions. In addition, the lens may be formed using a light-transmitting thermoplastic resin (eg, polymethyl methacrylate (PMMA), poly cabonate (PCMA), etc.) capable of forming a lens due to a small volume change when cured in a conventional liquid phase. When the wavelength band of the light emitted from 10) is 100nm to 400nm, the light transmittance of the light emitted from the semiconductor light emitting device chip 10 is 100nm to 400nm because the light transmittance is low and deteriorated so that it cannot be used. Lens is formed of a material such as glass, sapphire or quartz, but in order to solve this problem, in the present disclosure, a transparent thermoplastic resin having a transmittance of 90% or more for light having a wavelength range of 100 nm to 400 nm and poor deterioration is used. To form a lens-like encapsulant 12.

In addition, since the light extraction efficiency is different according to the refractive index of the lens, the difference between the refractive index of the outermost medium in contact with the air and the air and the refractive index should be minimized. For example, referring to FIG. 5B, a sapphire or 1.54 having a refractive index of 1.8 is an empty space A between the lens L and the semiconductor light emitting device chip 10b, and the lens L has a refractive index of 1.8. In the case of quartz having a refractive index, the refractive index change from the semiconductor light emitting device chip 10b to air changes in the order of 1 (A)-1.54 (L) or 1.8 (L)-1 (air). Changes are not made sequentially and light loss may occur.

However, in the present invention, when the encapsulant 12 is wrapped in contact with the semiconductor light emitting device chip 10 without empty space, and the refractive index of the transparent thermoplastic resin is 1.3, the refractive index from the semiconductor light emitting device chip 10 to air is increased. The change is 1.3 (12)-1 (air), so that no light loss occurs because the refractive index changes sequentially. Accordingly, the light extraction efficiency may be further improved by effectively preventing total reflection occurring at the interface when light enters the medium having a high refractive index from the medium having a small refractive index.

A method of forming the encapsulant 12 made of a translucent thermoplastic resin having a light transmittance of 90% or more for light having a wavelength range of 100 nm to 400 nm and having a large volume change when cured in a liquid phase will be described later with reference to FIGS. 6 to 9. do. At this time, the shape of the encapsulant 12 may have a hemispherical convex lens shape, but is not limited thereto. For example, the encapsulant 12 may be formed in a concave lens shape, a flat lens shape, a concave-convex lens shape, a conical lens shape or a geometrical lens shape. It can be modified to meet the requirements of efficiency and light distribution characteristics.

6 is a view illustrating an example of a method of manufacturing a semiconductor light emitting device according to the present disclosure.

In the method of manufacturing a semiconductor light emitting device, as illustrated in FIG. 6A, first, an external substrate is prepared, and then a plurality of electrodes of the conductive layer 242 of the external substrate 24 and the semiconductor light emitting device chip 20 ( The semiconductor light emitting device chip 20 is placed on the outer substrate 24 so that the 202 may face each other. Accordingly, the conductive layer 242 of the external substrate 24 and the plurality of electrodes 202 of the semiconductor light emitting device chip 20 are electrically connected to each other. Preparing an external substrate means forming a conductive layer, a barrier layer and a reflective layer on the base.

Here, the element transfer device 21 for recognizing the shape, pattern, or boundary of the conductive layer 242, the prevention layer 243, and the reflective layer 244 formed on the outer substrate 24 to correct the position and angle at which the element is placed. Using, the semiconductor light emitting device chip 20 is placed on the outer substrate 24.

Next, as shown in FIG. 6 (b), the solid preliminary encapsulant 4 made of a translucent thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm to surround the semiconductor light emitting device chip 20. Place it. In this case, the preliminary encapsulant 4 is disposed on the external substrate 24 and the semiconductor light emitting device chip 20 using the element transfer device 21. Here, the preliminary encapsulant 4 is disposed to be spaced apart from the semiconductor light emitting device chip 20 at predetermined intervals.

The preliminary encapsulant 4 is formed by solidifying a liquid-transmissive thermoplastic resin having a transmittance of 90% or more with respect to light having a wavelength band of 100 nm to 400 nm. For example, the liquid transparent thermoplastic resin is cured to form a solid preliminary encapsulant 4 having a volume reduced by about 90% or more. Specifically, referring to FIG. 7, the preliminary encapsulant 4 includes a main body portion 41 having a groove 43 and a support portion 42 connected to one side surface of the main body portion 41.

Since the preliminary encapsulant 4 is disposed to surround the semiconductor light emitting device chip 20, the width of the groove 43 of the main body part 41 is greater than the width of the semiconductor light emitting device chip 20, and the support part 42 is provided. ) Is preferably greater than the height of the semiconductor light emitting device chip 20. The method of manufacturing the preliminary encapsulant 4 will be described with reference to FIGS. 8 to 9.

Next, as shown in FIG. 6 (c), the preliminary encapsulant 4 is thermoset to form a hemispherical encapsulant 22 surrounding the semiconductor light emitting device chip 20. In this case, the shape of the encapsulant 22 may have a hemispherical convex lens shape, but is not limited thereto.

In the case where the preliminary encapsulant 4 is thermoset to form the encapsulant 22, the volume does not change significantly when the preliminary encapsulant 4 becomes the encapsulant 22. As shown in FIGS. 8 and 9, the preliminary encapsulant 4 is formed by reducing the volume of the liquid-transmissive thermoplastic resin 50 having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm. When the preliminary encapsulant 4 becomes the encapsulant 22, the volume change rate is 2% or less. When the preliminary encapsulant 4 is thermoset to form the encapsulant 22, the volume change rate is 2% or less, so that the lens shape of the encapsulant 22 may be implemented in various lens shapes in addition to the hemispherical convex lens shape. . That is, even if the preliminary encapsulant 4 is melted into a liquid phase and then made into a desired lens shape (for example, a convex lens shape, a concave lens shape and a conical lens shape), the desired lens shape can be easily produced because the volume change is small. have.

When the preliminary encapsulant 4 is thermally cured, the encapsulant 22 is not formed beyond the encapsulation layer 243 by the surface tension with the preventive layer 143 of the outer substrate 24. In this case, the prevention layer 243 may be formed at the same time when the conductive layer 242 of the external substrate 24 is formed, but may be formed through a separate process without being limited thereto. When the prevention layer 243 and the conductive layer 242 are formed at the same time, the manufacturing process can be shortened to reduce the manufacturing process time and manufacturing cost.

The heat treatment and / or drying for thermosetting the preliminary encapsulant 4 is preferably cured at high temperature. For example, it may be performed for about 4 hours to 6 hours at a temperature of 200 ℃ to 300 ℃. The above-described heat treatment and / or drying temperature and time is limited so that the solid resin layer 4 is cured to have a uniform top surface, and stable bonding with the semiconductor light emitting device chip 20 and the external substrate 24 may be achieved. It is not limited to this. Bubbles may occur when curing at high temperatures, but bubble generation may be removed using a vacuum oven.

Next, as shown in FIG. 6 (d), the individual semiconductor light emitting devices 2 are formed by cutting along the cutting lines 26.

8 to 9 are diagrams showing an example of a method of manufacturing a preliminary encapsulant made of a translucent thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm according to the present disclosure.

The preliminary encapsulant 4 is formed by a shrinkage and thermal compression method with reference to FIGS. 8 and 9.

Specifically, as shown in FIG. 8A, a photoresist layer 31 is formed on the first base layer 30. The photoresist layer 31 may be formed using a screen printing method or the like with a photoresist paste.

Next, as shown in FIG. 8 (b), after the mask 32 having a predetermined pattern is disposed on the photoresist layer 31, an exposure process is performed by irradiating light having a wavelength band of 100 nm to 400 nm. Do this. The mask 32 has a pattern in which the first region 33 is exposed.

When the light having a wavelength band of 100 nm to 400 nm is irradiated to the photoresist layer 31, the photoresist layer 31 of the first region 33 exposed to the light having a wavelength band of 100 nm to 400 nm by the mask 32 is harder. The photoresist layer 31 of the second region 34 that is overcured and is not exposed to light having a wavelength band of 100 nm to 400 nm by the mask 32 is not overcured.

Next, as shown in FIG. 8C, the photoresist layer 31 formed in the second region 34 except for the photoresist layer 31 photocured in the first region 33 through development. Etch process to remove). For example, the etching process may be performed by wet etching. For example, when the specimen is immersed in an inorganic acid-based developing solution containing at least one of hydrofluoric acid, nitric acid, acetic acid, sulfuric acid, and hydrochloric acid, the unetched portion may be The photoresist layer 31 is removed from the second region 34 so that the second region 34 exposes the first base layer 30 and the first region 33 except for the second region 34. The photoresist layer 31 remains.

Next, as shown in FIG. 8 (d), the metal layer 35 is formed in the second region 34 where the first base layer is exposed by the etching process. The metal layer 35 is not formed in the first region 33.

The metal layer 35 may be formed higher than the height of the photoresist layer 31. Alternatively, the metal layer 35 may be formed smaller or the same height. The metal layer 35 may be made of a metal material such as Au, Al, Ag, and the like, and may be formed through a deposition process such as physical vapor deposition (PECVD) or chemical vapor deposition (CVD), such as electron beam deposition, but is not limited thereto. It doesn't work.

Next, as shown in FIG. 8E, the photoresist layer 31 positioned in the first region 33 is removed by performing a lift off process to remove the photoresist layer 31 on the first base layer 30. Only the metal layer 35 formed only in the second region 34 is positioned.

Through the lift off process, an acid solution such as dilute hydrofluoric acid (DHF, Dilute HF) or HNO ₃ may be used to remove the photoresist layer 31 positioned in the first region 33.

Next, as shown in FIG. 8F, a dummy semiconductor light emitting device chip 36 is disposed on the metal layer 35. The metal layer 35 and the dummy semiconductor light emitting device chip 36 may be pressed by an external force to adhere to each other, or may be bonded to each other using an adhesive material (A). For example, the adhesive material (A) can be variously selected from conductive pastes, insulating pastes, polymer adhesives, AuSn solders, and the like, and is not particularly limited.

In the present disclosure, the size of the dummy semiconductor light emitting device chip 36 is larger than that of the semiconductor light emitting device chip 10 illustrated in FIG. 4, but may be the same or smaller.

Next, as illustrated in FIG. 8G, the dummy semiconductor light emitting device chip 36 and the metal layer 35, which are integrally formed on the first base layer 30, are disposed on the second base layer 37. It arrange | positioned so that it may correspond with the board | substrate 40 for sealing materials. The top surface of the dummy semiconductor light emitting device chip 36 faces the top surface of the substrate 40 for preliminary encapsulant.

At this time, the second base layer 37 is preferably a hot plate (hot plate) is maintained at a high temperature of about 200 ℃. As a result, the preliminary encapsulant substrate 40 disposed on the second base layer 37 is in a flexible state.

The substrate 40 for the preliminary encapsulant is formed in the shape of a flat top and bottom surfaces, and is made of a transparent thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm.

Specifically, referring to 9 (a), the liquid-transmissive thermoplastic resin 50 having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm is injected into the fixing frame 52 by using the first transfer part 51.

The fixing frame 52 may be a rigid metal plate or a non-metal plate, and may have a rigid material to some extent so as to maintain the shape of the liquid transparent thermoplastic resin 50 having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm. desirable. For example, Al, Cu, Ag, Cu-Al alloys, Cu-Ag alloys, Cu-Au alloys, SUS (stainless steel) and the like can be used, and plated plates can of course also be used.

Next, referring to FIG. 9 (b), the substrate 40 for preliminary encapsulant made of a solid is formed by thermosetting. The substrate 40 for the preliminary encapsulant is preferably formed by reducing the volume of the liquid transparent thermoplastic resin 50 having a transmittance of 90% or more to light having a wavelength band of 100 nm to 400 nm by 90% or more. That is, the volume of the solvent contained in the liquid transparent thermoplastic resin 50 is greatly reduced as the heat curing process proceeds to the thermosetting process of volatilizing and solidifying the solvent in the liquid transparent thermoplastic resin 50.

At this time, the thermosetting process for curing the liquid transparent thermoplastic resin 50 may be performed for about 15 to 20 hours at a temperature of 200 ℃ to 300 ℃, for example. Preferably, the thermal curing is carried out for 18 hours at a temperature of 250 ℃. The temperature and time according to the above-mentioned thermosetting process are limited so that the liquid-transmissive thermoplastic resin 50 may be cured at the same time to have a uniform and flat top surface, and to be stably coupled with the semiconductor light emitting device chip 20. It is not.

Next, referring to FIG. 9 (c), the substrate 40 for the preliminary encapsulant is separated from the fixing frame 52 and cut along the cutting line 53 such that the upper and lower surfaces of the substrate for the preliminary encapsulant 40 have a flat shape. Thus, the substrate 40 for the individual preliminary encapsulant is formed.

Next, as shown in FIG. 8H, the preliminary encapsulant substrate 40 is compressed by the dummy semiconductor light emitting device chip 36 by performing a thermal compression process. As described above, since the preliminary encapsulant substrate 40 is flexible by the second base layer 37 which maintains a high temperature, the preliminary encapsulant substrate 40 is compressed by the dummy semiconductor light emitting device chip 36 when the thermal compression process is performed. .

Next, as shown in FIG. 8I, a solid preliminary encapsulant 4 having a plurality of grooves 38 in accordance with the shape of the dummy semiconductor light emitting device chip 36 is formed. The depths of the plurality of grooves 38 are preferably formed to be the same as the height of the dummy semiconductor light emitting device chip 36, but may be formed larger or smaller than the height of the dummy semiconductor light emitting device chip 36.

Next, as shown in FIG. 8 (j), the preliminary encapsulant 4 is cut along the cutting line 39 so as to have each groove 38.

FIG. 10 is a diagram illustrating a problem of forming an encapsulant by directly using a liquid transparent thermoplastic resin having a transmittance of 90% or more for light having a wavelength range of 100 nm to 400 nm.

When the encapsulant is directly formed by using a liquid transparent thermoplastic resin having a transmittance of 90% or more for light having a wavelength range of 100 nm to 400 nm, the liquid transparent thermoplastic resin applied when thermal curing to cure the liquid transparent thermoplastic resin Since the volume of is reduced by about 90% or more, to form an encapsulant having a desired shape, it is necessary to repeatedly apply a liquid-transmissive thermoplastic resin and a thermosetting process.

The manufacturing process time and manufacturing cost can be increased by the application and thermosetting process of the repetitive liquid translucent thermoplastic resin.

For example, referring to FIG. 10 (a), the encapsulant 222a may be formed beyond the barrier layer 243a by a repetitive coating and thermosetting process of a liquid transparent light-transmitting thermoplastic resin. Accordingly, since the encapsulant 222a is not formed in a hemispherical convex lens shape, light distribution is not smoothly performed, light extraction efficiency is reduced, and reliability may be reduced. In addition, when the encapsulant 222a is formed beyond the prevention layer 243a, the encapsulant 222a may be formed to cover the reflective layer 244a, so that the reflection efficiency of the reflective layer 244a may be reduced to reduce light extraction efficiency. have.

In addition, referring to FIG. 10 (b), bubbles (B, Bubble) may be generated in the encapsulant 22b by repeatedly applying the liquid-transmissive thermoplastic resin and thermosetting processes.

The coating and thermosetting processes are repeated to form the encapsulant 22b into a hemispherical convex lens shape, and the cured encapsulant 22b is repeatedly cured, thereby applying the liquid-translucent thermoplastic resin and the cured encapsulant ( Bubbles B may occur at the surface of 22b) or inside the cured encapsulant 22b. Since the bubble B is generated inside the encapsulation material 22b, the encapsulation material 22b may not be uniformly formed, and light generated from the semiconductor light emitting device chip 20b may not be diffused smoothly, thereby reducing reliability.

11 illustrates another example of a method of manufacturing a semiconductor light emitting device according to the present disclosure.

Before the process of FIG. 6B, that is, before placing the preliminary encapsulant 4 to surround the semiconductor light emitting device chip 20, referring to FIG. 11A, the transmittance for light having a wavelength band of 100 nm to 400 nm is determined. 90% or more of the liquid transparent thermoplastic resin is applied to form the liquid resin layer 60. At this time, the liquid-transmissive thermoplastic resin having a transmittance of 90% or more for light having a wavelength range of 100 nm to 400 nm is through the second transfer part 61 which performs the same function as the first transfer part 51 shown in FIG. The semiconductor light emitting device chip 62 is coated to surround it.

Next, referring to FIG. 11 (b), the encapsulant layer 63 is formed by thermosetting the liquid resin layer 60. The encapsulant layer 63 is preferably formed by volatilizing the solvent by a thermosetting process to reduce the volume by 90% or more than the volume of the liquid resin layer 60. In the present disclosure, the encapsulant layer 63 is preferably formed to a thickness of about 10um.

Next, referring to FIG. 11 (c), the encapsulant 22 is formed by placing the preliminary encapsulant 64 on the encapsulant layer 63. At this time, the encapsulant layer 63 and the preliminary encapsulant 64 are made of the same material, so that the encapsulant layer 63 is formed on the preliminary encapsulant 64 when the thermosetting process is performed to form the encapsulant 22. Melts. Using the preliminary encapsulant 64 after forming the encapsulant layer 63 may form the lens faster even with less curing time than using the preliminary encapsulant 64 without using the encapsulant layer 63. In addition, as the encapsulant layer 63 is well filled between the electrodes of the semiconductor light emitting device chip, it helps to improve the adhesion between the external substrate and the semiconductor light emitting device chip.

The method of forming the encapsulant 22 using the preliminary encapsulant 64 is substantially the same as the method of manufacturing the semiconductor light emitting device shown in FIG.

Dupont's Teflon Af family includes a translucent thermoplastic resin having a transmittance of 90% or more for light having a wavelength range of 100 nm to 400 nm and deterioration due to light having a wavelength range of 100 nm to 400 nm.

The order of the manufacturing method of the semiconductor light emitting device according to the present disclosure may be included in the scope of the present disclosure in a range that can be easily changed by those skilled in the art.

Hereinafter, various embodiments of the present disclosure will be described.

(1) A semiconductor light emitting device comprising: a semiconductor light emitting device chip comprising a plurality of semiconductor layers including an active layer for generating light by recombination of electrons and holes, and electrodes electrically connected to the plurality of semiconductor layers; An encapsulant formed to enclose a semiconductor light emitting device chip; A lens encapsulant made of a transparent thermoplastic resin having a transmittance of 90% or more for light having a wavelength band of 100 nm to 400 nm; And an external substrate including a conductive layer electrically connected to an electrode of the semiconductor light emitting device chip, wherein the encapsulant has a front surface exposed to the outside except a bottom surface in contact with the external substrate.

(2) an outer substrate comprising a blocking layer located farther from the semiconductor light emitting device chip than the conductive layer, wherein the encapsulant covers at least a portion of the upper surface of the blocking layer.

(3) A semiconductor light emitting element in which an encapsulant covers the entire upper surface of the prevention layer.

(4) A semiconductor light emitting element in which the height of the prevention layer is less than or equal to the height of the conductive layer.

(5) The outer substrate is a semiconductor light emitting device comprising a; reflective layer located on the upper surface of the outer substrate spaced apart from the prevention layer.

(6) The semiconductor light emitting element which is not covered by an encapsulant among the side surfaces of the prevention layer located between the prevention layer and the reflective layer.

(7) The semiconductor light emitting element, wherein the prevention layer is made of one metal material of Au and Al.

(8) A semiconductor light emitting element, wherein the prevention layer forms a closed circuit with no gaps.

(9) A semiconductor light emitting element chip is a semiconductor light emitting element that emits light having a wavelength band of 100 nm to 400 nm.

(10) The lens shape of the encapsulant is at least one of a convex lens shape, a concave lens shape, a flat lens shape, a concave-convex lens shape, a conical lens shape or a geometric lens shape.

According to the present disclosure, a semiconductor light emitting device capable of reducing a bubble phenomenon caused by thermal expansion or contraction generated during curing by curing the sealing material in an open state of at least one of the upper and lower surfaces of the sealing material is provided. .

According to the present disclosure, when forming an encapsulant, light having a wavelength band of 100 nm to 400 nm generated in a semiconductor light emitting device chip is smoothly encapsulated by using a transparent thermoplastic resin having a transmittance of 90% for light having a wavelength band of 100 nm to 400 nm. The light distribution efficiency can be smoothly transmitted to improve light extraction efficiency.

The encapsulant is a solid, transparent thermoplastic resin having a transmittance of 90% for light having a wavelength range of 100 nm to 400 nm and a volume of 90% or less of a liquid transparent thermoplastic resin having a transmittance of 90% for light having a wavelength range of 100 nm to 400 nm. Is done.

According to the present disclosure, there is provided a semiconductor light emitting device which prevents the encapsulant from being formed over the protective layer by the protective layer when the encapsulant is cured.

Semiconductor light emitting device: 1, 2, 400
Semiconductor light emitting chip: 10, 20, 36, 450
Outer substrate: 14, 24 layer: 143, 243
Spare Encapsulant: 4

Claims (10)

In a semiconductor light emitting device,
A semiconductor light emitting device chip comprising a plurality of semiconductor layers including an active layer for generating light by recombination of electrons and holes, and electrodes electrically connected to the plurality of semiconductor layers;
An encapsulant formed to surround the semiconductor light emitting device chip; a encapsulant formed of a transparent thermoplastic resin having a transmittance of 80% or more for light having a wavelength band of 100 nm to 400 nm; And
And an external substrate including a conductive layer electrically connected to the electrodes of the semiconductor light emitting device chip.
The encapsulant is exposed to the outside except for the lower surface in contact with the outer substrate.
The encapsulant is formed in one layer,
The encapsulant is formed in contact with the semiconductor light emitting device chip,
The outer substrate includes a barrier layer located farther from the semiconductor light emitting device chip than the conductive layer.
The encapsulant covers at least a portion of the top surface of the barrier layer,
The outer substrate is a reflective layer positioned on the upper surface of the outer substrate at a predetermined distance from the prevention layer; a semiconductor light emitting element comprising a reflection layer surrounding the prevention layer to form a closed circuit. delete The method according to claim 1,
A semiconductor light emitting device in which an encapsulant covers the entire upper surface of the prevention layer. The method according to claim 1,
A semiconductor light emitting element, wherein the height of the prevention layer is less than or equal to the height of the conductive layer. delete The method according to claim 1,
The side surface between the prevention layer and the reflective layer among the side surfaces of the prevention layer is not covered with an encapsulant. The method according to claim 1,
The prevention layer is a semiconductor light emitting device consisting of a metal material of Au and Al. The method according to claim 1,
The prevention layer is a semiconductor light emitting device forming a closed circuit without a gap. The method according to claim 1,
The semiconductor light emitting device chip is a semiconductor light emitting device for emitting light having a wavelength band of 100nm to 400nm. The method according to claim 1,
The lens shape of the encapsulant is at least one of a convex lens shape, a concave lens shape, a lens shape of the upper surface is flat, a lens shape of irregularities, a lens shape of a cone or a lens shape of a geometric structure.

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