KR20190126547A - Semiconductor light emitting device - Google Patents

Abstract

The present invention relates to a semiconductor light emitting element which comprises: a semiconductor light emitting element chip having a plurality of semiconductor layers including an active layer generating UV rays by recombination of an electron and a positive pole and an electrode electrically connected to the plurality of semiconductor layers; an encapsulment formed to cover the semiconductor light emitting element chip; and an external substrate having a base and a conductive layer electrically connected with the electrode of the semiconductor light emitting chip. A planar surface of the external substrate in contact with a lower surface of the encapsulment is smaller than a planar surface of the external substrate not in contact with the lower surface of the encapsulment.

Description

Semiconductor Light Emitting Device {SEMICONDUCTOR LIGHT EMITTING DEVICE}

The present disclosure relates to a semiconductor light emitting device as a whole, and more particularly to a semiconductor having improved light extraction efficiency.

This section provides background information related to the present disclosure which is not necessarily prior art.

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 610 (eg, a sapphire substrate), a growth layer 610, a buffer layer 620, a first semiconductor layer 630 having a first conductivity (eg, an n-type GaN layer), and electrons. An active layer 640 (eg, INGaN / (In) GaN MQWs) that generates light through recombination of holes, and a second semiconductor layer 650 (eg, p-type GaN layer) having a second conductivity different from the first conductivity are sequentially And a translucent conductive film 660 for spreading current and an electrode 670 serving as a bonding pad, and serving as a bonding pad on the etched and exposed first semiconductor layer 630. An electrode 680, 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, when the growth substrate 610 side is electrically connected to the outside becomes a mounting surface. 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 610 and a growth substrate 610, a first semiconductor layer 630 having a first conductivity, an active layer 640 that generates light through recombination of electrons and holes, and a first conductivity. A second semiconductor layer 650 having a second conductivity different from that of the second semiconductor layer 650 is sequentially deposited, and three electrode layers 690, 691, and 692 are formed thereon to reflect light toward the growth substrate 610. have. The first electrode film 690 may be an Ag reflecting film, the second electrode film 691 may be a Ni diffusion barrier film, and the third electrode film 692 may be an Au bonding layer. An electrode 680, which functions as a bonding pad, is formed on the etched and exposed first semiconductor layer 630. Here, when the electrode film 692 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 680 formed on the first semiconductor layer 630 is lower than the electrode films 690, 691, and 692 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 610.

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

The semiconductor light emitting device 700 includes a vertical semiconductor light emitting chip 750 in the lead frames 710 and 720, the mold 730, and the cavity 740, and the cavity 740. Is filled with an encapsulant 770 containing the wavelength converting member 160. A lower surface of the vertical semiconductor light emitting device chip 750 is electrically connected directly to the lead frame 710, and an upper surface thereof is electrically connected to the lead frame 720 by a wire 780. A portion of the light emitted from the vertical semiconductor light emitting device chip 750 may excite the wavelength converting material 760 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 750 may generate blue light, and light generated by being excited by the wavelength converting material 760 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 750, 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 ultraviolet 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 surround the semiconductor light emitting device chip; And an outer substrate having a base and a conductive layer electrically connected to the electrodes of the semiconductor light emitting device chip, wherein the plane of the outer substrate in contact with the lower surface of the encapsulant is smaller than the plane of the outer substrate not in contact with the lower surface of the encapsulant. A semiconductor light emitting device is provided.

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 to 10 is a view showing a feature related to the diameter size of the encapsulant in the semiconductor light emitting device according to the present disclosure,
11 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;
12 illustrates an example of a method of manufacturing a semiconductor light emitting device according to the present disclosure;
13 is a view showing an example of a preliminary encapsulant according to the present disclosure;
14 to 15 are views showing an example of a method of manufacturing a pre-sealing material made of a transparent thermoplastic resin having a transmittance of 80% or more with respect to ultraviolet rays according to the present disclosure,
16 is a view showing a problem in the case of forming an encapsulant using a liquid transparent light-transmitting thermoplastic resin having a transmittance of 80% or more to the conventional ultraviolet ray,
17 is a view showing another example of a method of manufacturing a semiconductor light emitting device according to the present disclosure;
18 illustrates another example of a method of manufacturing a semiconductor light emitting device according to the present disclosure;
19 illustrates another example of a semiconductor light emitting device according to the present disclosure;
20 is a view showing another example of 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). In addition, in the present specification, direction indications such as up / down, up / down, etc. are based on the drawings.

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 plan 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 illustrated as a flip chip in this embodiment, the lateral chip and the vertical chip are not excluded. The active layer 101 is exaggerated for clarity.

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 the lower surface of 4 mm at most. The translucent thermoplastic resin is preferably a translucent thermoplastic resin having a transmittance of 80% or more with respect to ultraviolet rays (for example, light having a wavelength band of 100 nm to 400 nm). Further preferably, the transparent thermoplastic resin is preferably a transparent thermoplastic resin having a transmittance of 90% or more against ultraviolet rays.

In this embodiment, the semiconductor light emitting device chip 10 may emit ultraviolet light. Preferably it emits ultraviolet light in the range of 200nm to 280nm UV-C wavelength band. Therefore, the encapsulant 12 made of a light-transmitting thermoplastic resin having a light transmittance of 80% or more with respect to ultraviolet rays acts as a lens to smoothly distribute light (light distribution). extraction efficiency can be improved.

In addition, the translucent thermoplastic resin having a transmittance of 80% or more to ultraviolet rays is preferably a thermoplastic resin having low damage even after long exposure to ultraviolet rays.

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 may include a base 141, conductive layers 142 and 145, a protective 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 be made of 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. In addition, the conductive layers 142 and 145 may be formed as a single layer or may be formed as a plurality of layers. 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, the protection layer 143 may be made of a material different from the silicon material (eg, a metal material). In particular, when the prevention layer 143 is made of a metal material, the adhesion between the external substrate 14 and the encapsulant 12 may be increased, thereby improving reliability. In addition, since the conductive layer 142, which is a metal material, may be formed at the same time, the manufacturing process may be shortened to reduce manufacturing process time and manufacturing cost.

The prevention layer 143 serves as a dam, but does not prevent the translucent thermoplastic resin forming the encapsulation material 12 from flowing out like a wall, but instead forms an upper surface of the prevention layer 143 and the lower surface of the encapsulation material 12 when the encapsulant 12 is formed. Since the encapsulant 12 is not formed beyond the protective layer 143 by the surface tension generated therebetween, the encapsulant 12 may be formed so as to cover the whole or part of the upper surface of the protective layer 143. Preferably, an encapsulant is formed at an edge portion where the top surface 1431 and the side surface of the prevention layer 143 meet the outer surface 1432 of the prevention layer 143 in the direction of the reflective layer 144 and the top surface 1431 of the prevention layer 143. It is preferable that the encapsulant 12 covers the entire upper surface 1431 of the prevention layer 143 because the surface tension effect generated between the 12 and the upper surface 1432 of the prevention layer 143 is maximized. In particular, when the angle 1433 formed between the upper surface 1431 and the outer surface 1432 of the prevention layer 143 is vertical, the surface tension effect generated between the encapsulant 12 and the upper surface 1431 of the prevention layer 143 is maximized. do. In addition, in order to prevent the encapsulant 12 from flowing out, the prevention layer 143 is preferably formed in a closed loop without a gap. In addition, when the barrier layer 143 is formed of a metal material, the surface tension generated between the encapsulant 12 formed of the thermoplastic resin is maximized, so that the encapsulant 12 may be better formed in a lens shape. However, when the prevention layer 143 is formed of a metal material and simultaneously forms a closed circuit shape, the base 141 is preferably formed of an insulating material to prevent a short. For better understanding, the upper surface 1431 and the outer surface 1432 of the prevention layer 143 are enlarged and illustrated in a circle. However, at this time, the inner surface 1434 of the prevention layer 143 may be covered by the encapsulant 12, and the outer surface 1432 of the prevention layer 143 may not be covered by the encapsulant 12. In the present disclosure, the diameter size of the lower surface of the encapsulant 12 is important and the reason will be described in FIG. 5. Therefore, the prevention layer 143 which controls the diameter size of the lower surface of the encapsulant 12 is an important component. In addition, the present disclosure does not exclude the blocking layer 143 from blocking like a wall.

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. When the conductive layer 142, the barrier layer 143, and the reflective layer 144 are all formed of the same material (eg, Au), three layers may be formed at a time, thereby simplifying the manufacturing process. As a method of forming a layer of a metal material on the base 141, a method such as 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 light emitted from the semiconductor light emitting device chip 10 is ultraviolet light, it is preferable to form the reflective layer 144 with Al having high reflection efficiency.

Also, the reflective layer 144 is formed between the conductive layer 142 and the prevention layer 143 (see FIG. 18), is formed only between the conductive layer 142 and the prevention layer 143 (see FIG. 19), or the reflective layer 144. May not be formed (see FIG. 20).

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 to 10 is a view showing the characteristics related to the size of the lower surface of the encapsulant in the semiconductor light emitting device according to the present disclosure.

The planar size of the encapsulant 12 in the semiconductor light emitting device 1 may be equal to or smaller than the planar size of a portion surrounded by the closed layer prevention layer 143. As shown in FIG. 4, when the surface tension between the encapsulant 12 and the barrier layer 143 is greatest, the lower surface of the encapsulant 12 covers the entire upper surface of the barrier layer 143. The planar size of is preferably equal to the planar size of the portion surrounded by the barrier layer 143. For example, when the plane of the encapsulant 12 and the plane surrounded by the barrier layer 143 are circular as shown in FIG. 4, the diameter 1431 of the lower surface of the encapsulant 12 and the diameter 1431 of the barrier layer 143 are shown. Have the same size. FIG. 5 shows that the applicant found through the experiment that the lower surface diameter of the encapsulant 12 surrounding the semiconductor light emitting device chip emitting ultraviolet light increases as the value of ΔPo increases. This means that as the diameter of the lower surface of the encapsulant 12 decreases, the amount of light lost by reflection in the encapsulant 12 decreases, so that the value of ΔPo increases. The semiconductor light emitting device chip 10, the conductive layer 143, and the prevention layer 143 are located inside the encapsulant 12 and reflect light emitted from the semiconductor light emitting device chip 10. That is, the surface from which the light emitted from the semiconductor light emitting device chip 10 is reflected inside the encapsulant 12 may be formed on the top and side surfaces of the semiconductor light emitting device chip 10, and the top and conductive surfaces of the conductive layer 142 and the prevention layer 143. It may be an upper surface of the base 141 exposed between the layer 143 and the prevention layer 143, and light is lost inside the encapsulant 12 by reflection with these various surfaces. In the case of emitting light other than the conventional ultraviolet light (for example, blue light), the loss of light generated inside the encapsulant is not a big problem. This is because a reflective surface can be formed by using a reflective material having a high reflection efficiency with respect to light other than ultraviolet rays inside the encapsulant. However, in the case of ultraviolet light having a short wavelength, a reflective material having high reflection efficiency does not vary, and furthermore, in the case of the conductive layer 143, a material having low reflection efficiency with respect to ultraviolet light (eg, Au) may be used. In the light emitting device, light loss due to reflection inside the encapsulant is a big problem. In particular, in the semiconductor light emitting device that emits ultraviolet rays having the wavelength of the UV-C band having the shortest wavelength among the ultraviolet rays, the light loss due to reflection in the encapsulant becomes a greater problem. Applicant compared with the case where the reflecting surface is formed of a material having a high reflectance when the diameter of the lower surface of the encapsulation material 12 becomes smaller than a predetermined size even when the reflecting surface formed inside the encapsulating material is made of a material having a low reflectance against ultraviolet rays. When the difference was found, the difference in ΔPo value was found to be small. In particular, it was found that even if the lower surface diameter of the encapsulant 12 is small, the difference in the value of ΔPo does not change significantly around 5%. This will be described in detail with reference to FIGS. 5 to 10.

ΔPo (light growth rate) is Po1 when the light amount of the semiconductor light emitting element when the lens-shaped encapsulant 12 is not formed and Po2 when the light amount of the semiconductor light emitting element on which the lens-shaped encapsulant 12 is formed is Po2. The value of / Po1. For example, when ΔPo is 150%, it means that the amount of light has increased by 50% compared with the case where no lens-shaped encapsulant is used. That is, when the lens-shaped encapsulant 12 is formed, the amount of light of the semiconductor light emitting device is increased. In particular, when the lens shape is hemispherical, the amount of light can be greatly increased. The first graph 15 is a case in which the reflective layer 144, the conductive layer 142, and the barrier layer 143 are formed of a material (eg, Al) having a 90% or more reflectance to ultraviolet rays, and the second graph 16 is a reflective layer. The conductive layer 142 and the barrier layer 143 are formed of a material (eg, Au) having a reflectance of 40% or less against ultraviolet rays. In the first graph 15 and the second graph 16, the UV loss due to reflection occurring inside the lens-shaped encapsulant 12 decreases as the diameter of the lower surface of the encapsulant 12 decreases, so that the ΔPo value. This shows a gradual increase. In particular, when the first graph 15 using a material having a reflectance of ultraviolet rays of 90% or more has the lower surface diameter of the same encapsulant 12, the second graph 16 using a material having a reflectance of ultraviolet light of 40% or less is used. Show larger ΔPo values. However, as the diameter of the lower surface of the encapsulant 12 decreases, the difference between the first graph 15 and the second graph 16 decreases. For example, when the lower surface diameter of the encapsulant is 3.4 mm (151, 161), the difference between the first graph 15 and the second graph 16 was 13%, but the lower surface diameter of the encapsulant was 2.1 mm (152, 162), the difference between the first graph 15 and the second graph 16 became 5%. That is, as the diameter of the encapsulant decreases, the reflectance of the material forming the protective layer 143 and the conductive layer 142 formed in the encapsulant 12 to the ultraviolet rays is gradually increased due to the light loss due to the reflection generated inside the encapsulant. When the encapsulant has a smaller effect and the diameter becomes smaller than a certain size, even if the reflecting surface formed inside the encapsulating material has a low reflectance against ultraviolet rays, it is almost no difference from the case where the reflecting surface is formed of a material having a high reflectance. The inventors found that However, the smaller the diameter, the smaller the difference in ΔPo value is, and the difference in ΔPo value remains almost constant as the dotted line (153, 163) from 5% or less. Showed.

In general, since it is desirable to have a high light growth rate in a semiconductor light emitting device, a material having a high reflectance against ultraviolet rays (for example, Al having 90% or more) is used for an ultraviolet reflecting surface (for example, a conductive layer or a protective layer) formed inside the encapsulant. It is expected. However, when the conductive layer 142 and the prevention layer 143 are formed of a material having a reflectance of about 90% or more with UV, for example, Al, a portion made of Al is conductive when the conductive layer 142 is formed of a plurality of layers. The upper portion of the layer 142 reflects ultraviolet rays well, but when the electrodes 102 of the semiconductor light emitting chip 10 are electrically connected by bonding to the electrodes of the semiconductor light emitting chip 10 by a method such as soldering or eutectic bonding, the electrodes 102 of the semiconductor light emitting chip 10 A problem arises in that the conductive layer 142 was hardly bonded to a portion made of Al. Accordingly, in the present exemplary embodiment, the conductive layer 142 is formed using gold (Au), which is a material to which the electrode 102 of the semiconductor light emitting device chip 10 may be well bonded to the conductive layer 142. However, gold (Au) has a problem that the ΔPo value is low because the material has a reflectance of 40% or less.

Applicant, based on what is found in the present disclosure, reflectance of ultraviolet light is less than 90%, but the conductive layer 142 is formed of a material that is well bonded with the electrode of the semiconductor light emitting device chip 10, The size of the lower surface diameter of the encapsulant 12 was limited to have a ΔPo value similar to that of the case in which the conductive layer 142 was formed of 90% or more of the material. Preferably, the diameter of the lower surface of the encapsulant 12 is within a size such that a difference between the values of ΔPo in the case of using a material having a reflectance to ultraviolet rays of 90% or more and a material having a reflectance to ultraviolet rays of 40% or less is within 5%. The size of was to be formed. For example, referring to FIGS. 6 and 7 illustrating the size of the semiconductor light emitting device used to obtain the graph of FIG. 5, when the encapsulant has a diameter of 2.1 mm, the difference ΔPo is within 5%. The size of the semiconductor light emitting device chip used in FIGS. 6 and 7 is 1.125mm * 1.125mm * 0.15mm, and FIG. 6 is a case where Au is used for the conductive layer 142, the reflective layer 144, and the prevention layer 143. 7 illustrates the case where Al is used for the conductive layer 142, the reflective layer 144, and the prevention layer 143. The width of the prevention layer 143 is 0.1 mm. In addition, the planar size of the semiconductor light emitting device is a planar size of the external substrate 14, which requires a certain size depending on the application of the semiconductor light emitting device. For example, in the semiconductor light emitting device of FIGS. 6 and 7, the planar size of the outer substrate 14 is kept constant at 6 mm * 6 mm, but according to the present disclosure, since the size of the bottom surface of the encapsulant 12 is smaller, ΔPo When the difference is less than 5%, the planar area of the outer substrate in contact with the lower surface of the encapsulant may be smaller than the planar area of the outer substrate not in contact with the lower surface of the encapsulant. That is, in comparison with FIGS. 8A and 8B, the semiconductor light emitting device illustrated in FIG. 8A is a semiconductor light emitting device that emits ultraviolet rays having a plane size of 3.5 mm * 3.5 mm. The conventional semiconductor light emitting device shows that the planar area of the outer substrate 14 in contact with the bottom surface of the encapsulant 12 is larger than the planar area of the outer substrate 14 not in contact with the lower surface of the encapsulant 12. It is because the quantity of light became known conventionally that the larger the lens-shaped sealing material is. However, FIG. 8B illustrates a semiconductor light emitting device according to the present disclosure, in which the plane of the outer substrate 14 in contact with the bottom surface of the encapsulant 12 is greater than the plane of the outer substrate 14 not in contact with the bottom surface of the encapsulant 12. Show small things According to the findings of the applicant in the present disclosure, when the semiconductor light emitting device emits ultraviolet rays, the smaller the diameter of the lower surface of the lens-shaped encapsulant is, the larger the amount of light is. In particular, the semiconductor light emitting device according to the present disclosure compares FIG. 9 (a) having a planar area of 3.5 mm * 3.5 mm with an external substrate 14 and FIG. 9 (b) having a plane area of 6 mm * 6 mm of the outer substrate 14. When the planar area of the substrate 14 is large, it can be seen that the planar difference between the planar surface of the outer substrate 14 in contact with the lower surface of the encapsulant 12 and the outer substrate not in contact with the lower surface of the encapsulant 12 is greater.

In addition, the portion of the encapsulant having the greatest influence on light loss due to reflection is the conductive layer 142. The prevention layer 143 has a width less than 0.1 mm, and a portion exposed to ultraviolet light is not large, and the semiconductor light emitting device chip 10 may be formed in a structure having high reflection efficiency against ultraviolet light, including a reflective layer reflecting ultraviolet light with a flip chip structure. Because there is. However, a part of the conductive layer 142 is covered with the semiconductor light emitting device chip 10, and thus there is a part not exposed to ultraviolet rays. Therefore, the exposed portion of the conductive layer 142 that is not covered with the semiconductor light emitting device chip 10 greatly affects the light loss due to reflection in the encapsulant 12. The planar size of the semiconductor light emitting device chip 10 may vary according to the type of the semiconductor light emitting device chip 10. In general, a large area chip and a small area chip are classified according to the planar size of the semiconductor light emitting device chip 10. Large-area chips when the planar size of the semiconductor light-emitting element chip 10 in plan size refers to or less than 0.8mm ² 1.5mm ² small area chip is a semiconductor light emitting device chip 10 is 0.06mm or less of at least 0.3mm ^{2 2} Say. 10 is a value of ΔPo in the case of using a material having a reflectance with respect to ultraviolet rays of 90% or more and a material having a reflectance with ultraviolet rays of 40% or less for the conductive layer 142 according to various types of semiconductor light emitting device chips 10. The total area of the conductive layer 142 and the size of the exposed conductive layer 142 are shown to be within 5%. For example, when the area of the semiconductor light emitting device chip 10, which is one of the large area chips, is 1.1532 mm ² , the total area of the conductive layer 142 is 2.0998 mm ² and the area of the exposed conductive layer 142 is 0.9466 mm ² or less. The difference between the ΔPo values between the conductive layer 142 and the ultraviolet ray having a reflectance of more than 90% and the ultraviolet ray having a reflectance of 40% or less is within 5%. In addition, when the area of the semiconductor light emitting device chip 10, which is one of the small area chips, is 0.105 mm ² , the conductive area 142 has a total area of 0.7054 mm ² and the exposed conductive layer 142 has an area of 0.6004 mm ² or less. It is shown that the difference between the ΔPo values within the layer 142 using a material having a reflectance of UV of 90% or more and a material having a reflectance of UV of 40% or less is within 5%. In addition, referring to FIG. 10, when a large area chip is used, when a total area of the conductive layer 142 and an area ratio of the exposed conductive layer 142 are 35% or more and 45% or less, a material having a 90% or more reflectance to ultraviolet rays is used. It is shown that the difference of ΔPo value within 5% when using a material having a reflectance of 40% or less to ultraviolet rays is used. On the other hand, when a small area chip is used, when the total area of the conductive layer 142 and the area ratio of the exposed conductive layer 142 are greater than or equal to 70% and less than or equal to 85%, a material having a reflectance of greater than or equal to 90% is used. It is shown that the difference in ΔPo value within 5% when using a material having a reflectance of 40% or less. Using the experimental results first discovered in the present disclosure, considering the planar size of the semiconductor light emitting device chip, the total area of the conductive layer 142 and the area ratio of the exposed conductive layer 142, a material having a reflectance to ultraviolet rays of 90% or more is used. The total area of the conductive layer can be specified so that the difference in ΔPo value within 5% or less in the case of using a material having a reflectance of 40% or less to ultraviolet rays can be specified. The diameter of can also be specified. However, looking at the results of the two-dimensional size of the conductive layer 142 is exposed, regardless of the types of large-area chips and small area chip is preferably at least 0.45mm ² 1.0mm ² or less.

When a semiconductor light emitting device chip having a planar size other than that specified in the present disclosure is used, a material having a reflectance of about 90% or more according to the planar size of the semiconductor light emitting device chip and having a reflectance of about 40% or less When the material is used, the total area of the conductive layer 142 and the area ratio of the exposed conductive layer 142 or the planar size of the exposed conductive layer 142 are satisfied. Although it may be beyond the size defined in the disclosure, the difference between the ΔPo values within the conductive layer 142 using a material having a reflectance of UV of 90% or more and a material having a reflectance of UV of 40% or less is within 5%. If it corresponds to the range to be included in the scope of the present disclosure.

The experimental method obtained the experimental results described in FIGS. 5 to 10 bonds a semiconductor light emitting device chip of similar or equivalent performance to each semiconductor light emitting device, wherein the bonding is either soldering or Jewish bonding. After that, the first optical measurement is performed to obtain a value of Po1. In the case of optical measurement, the measurement was carried out using Spectrometer CAS-140CT and integrating sphere ISP-250 of Instrument Systems. Since the encapsulation material is implemented to form a lens. The secondary light measurement is then performed to obtain the value of Po2. The conditions are the same as those for the primary light measurement. After that, the primary and secondary optical characteristics were compared.

In addition, although forming the encapsulant 12 on the conductive layer 142 can minimize the diameter of the lower surface of the encapsulant 12, the conductive layer 142 is a conductive layer 142 in order to prevent a short There is an open portion 1421. Insulating material may be filled in the open portion 1421, but even when the insulating material is filled, the encapsulant 12 may be disposed between the lower surface of the encapsulant 12 and the upper surface of the conductive layer 142 because of the open portion 1421. The encapsulant 12 is not formed only on the upper surface of the conductive layer 142 but is formed out of the conductive layer 142 only by the surface tension generated in the upper surface. Thus, the encapsulant 12 having a lens shape is formed only on the upper surface of the conductive layer 142. Not desirable to Accordingly, the prevention layer 143 in the form of a closed loop was formed to protrude from the upper surface of the base 141 without an open section within a gap within 200 μm from the conductive layer 142. In particular, since there is no reflective layer between the conductive layer 142 and the prevention layer 143, the groove 1422 is formed so that the prevention layer 143 may function as a dam when the encapsulant 12 is formed, but this embodiment In this case, the height of the barrier layer 143 is the same as or smaller than the height of the conductive layer 142, so that the height of the barrier layer 143 is low to function as a dam. However, as shown in FIG. 4, the dam role which prevents the encapsulant 12 from being formed beyond the barrier layer 143 by using the surface tension generated between the upper surface of the barrier layer 143 and the lower surface of the barrier material 12 should be sufficient. Can be. In FIG. 4, the closed circuit of the protection layer 143 has a circular shape, but may be modified as necessary. In addition, in the present embodiment, Au is used as a material for forming the conductive layer and the prevention layer in contact with the lower surface of the encapsulant. However, in addition to Au, the material has a low reflectance against ultraviolet rays and can be bonded by a method such as soldering or eutectic bonding with a semiconductor light emitting device chip. Metallic materials (eg Ag) with good bonding strength can also be used. In addition, in the present embodiment, a material having a low reflectance of 40% to UV is a preferable example of the present disclosure, and a material having a high UV reflectance such that a semiconductor light emitting device may have a high ΔPo value even when emitting a UV light (eg, ultraviolet light). Materials other than Al, such as Al having a reflectance of 90% or more, (eg, UV reflectance of less than 90%) may be included in the scope of the present disclosure.

11 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. 11A, in the semiconductor light emitting device, a preformed lens L may be attached onto the semiconductor light emitting device chip 10a.

However, the present disclosure implements a lens shape by using the encapsulant 12 made of a light-transmitting thermoplastic resin, and thus may not further include a separate lens, thereby further miniaturizing the semiconductor light emitting device. Furthermore, the size of the encapsulant 12 can be efficiently controlled using the prevention layer 143. However, in the case of the translucent thermoplastic resin having a transmittance of 80% or more of the translucent thermoplastic resin, most of the solvent is volatilized and the volume is reduced by 90% or more when cured and solidified in the liquid phase. It was difficult to implement a lens-shaped encapsulant 12 using a resin. In the present disclosure, the lens-shaped encapsulant 12 formed of a light-transmitting thermoplastic resin having a transmittance of 80% or more with respect to ultraviolet rays is solved. Furthermore, when the encapsulant 12 encapsulating the semiconductor light emitting device chip 10 while being in contact with the external substrate 14 by implementing the lens-shaped encapsulant 12 using a transparent thermoplastic resin having a transmittance of 80% or more against ultraviolet rays, Except for the portion, the encapsulant 12 having the front surface exposed to the outside becomes possible, and thus, the ultraviolet light emitted from the semiconductor semiconductor light emitting device chip 10 and passing through the encapsulant 12 is removed except for the direction of the external substrate 14. It was possible to go directly in the direction. 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. 10) When the light emitted from the ultraviolet light is low transmittance and could not be used because it is deteriorated well when the light emitted from the semiconductor light emitting device chip (10) is conventionally a material such as glass, sapphire or quartz, not a transparent thermoplastic resin In order to solve this problem, in the present disclosure, a lens-shaped encapsulant 12 is formed by using a transparent thermoplastic resin having a transmittance of 80% or more and not deteriorating well.

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. 11B, 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 disclosure, when the encapsulant 12 is wrapped in contact with the semiconductor light emitting device chip 10 without a space and the refractive index of the transparent thermoplastic resin is 1.3, the refractive index change from the semiconductor light emitting device chip 10 to air is changed. 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.

Such a method of forming the encapsulant 12 made of a translucent thermoplastic resin having a transmittance to ultraviolet rays of 80% or more and a large volume change when cured in a liquid phase will be described later with reference to FIGS. 12 to 15. 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.

12 is a diagram 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 shown in FIG. 12A, first, an external substrate 24 is prepared, and then a plurality of conductive layers 242 and semiconductor light emitting device chips 20 of the external substrate 24 are prepared. The semiconductor light emitting device chip 20 is placed on the outer substrate 24 so that the electrodes 202 of the electrodes 202 correspond to 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. 12B, a solid preliminary encapsulant 4 made of a translucent thermoplastic resin having a transmittance of 80% or more with respect to ultraviolet rays is disposed to surround the semiconductor light emitting device chip 20. 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 may be disposed to be spaced apart from the semiconductor light emitting device chip 20 at predetermined intervals.

The preliminary encapsulant 4 may be formed into a solid by curing a liquid-transmissive thermoplastic resin having a transmittance of 80% or more to ultraviolet rays. For example, the liquid transparent thermoplastic resin may be cured to form a solid preliminary encapsulant 4 having a volume reduced by about 90% or more. Specifically, the preliminary encapsulant 4 is shown in FIG.

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 sealing material 4 is demonstrated in FIGS. 14-15.

Next, as shown in FIG. 12 (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. 14 and 15, the preliminary encapsulant 4 is formed by reducing the volume of the liquid translucent thermoplastic resin 50 having a transmittance of 80% or more to ultraviolet rays by 90% or more. ) Is the encapsulant 22 may have a volume change rate of 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 243 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. 12 (d), the individual semiconductor light emitting devices 2 are formed by cutting along the cutting lines 26.

13 is a view showing an example of a preliminary encapsulant according to the present disclosure.

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.

14 to 15 are views showing an example of a method of manufacturing a preliminary encapsulant made of a transparent thermoplastic resin having a transmittance of 80% or more with respect to ultraviolet rays according to the present disclosure.

The preliminary encapsulant 4 is formed by a shrinkage and thermal compression method with reference to FIGS. 14 and 15.

Specifically, as shown in FIG. 14A, 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. 14B, a mask 32 having a predetermined pattern is disposed on the photoresist layer 31 and then exposed to ultraviolet rays to perform an exposure process. The mask 32 has a pattern in which the first region 33 is exposed.

When the ultraviolet rays are irradiated onto the photoresist layer 31, they are hardened more hardly than the photoresist layer 31 of the first region 33 exposed to the ultraviolet rays by the mask 32, and are exposed to the ultraviolet rays by the mask 32. The photoresist layer 31 of the second region 34 that is not exposed is not hardened.

Next, as shown in FIG. 14C, 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 illustrated in FIG. 14D, 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. 14E, the photoresist layer 31 positioned in the first region 33 is removed by performing a lift off process to remove the photoresist layer 31 located on the first base layer 30. Only the metal layer 35 formed only in the second region 34 is positioned. The metal layer 35 is for improving the adhesive force when soldering and bonding the dummy semiconductor light emitting device chip 36 as shown in FIG. 14 (f).

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. 14F, 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.

Although the size of the dummy semiconductor light emitting device chip 36 is larger than that of the semiconductor light emitting device chip 10 shown in FIG. 4, the dummy semiconductor light emitting device chip 36 may be the same or smaller.

Next, as shown in FIG. 14G, 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 light-transmitting thermoplastic resin having a transmittance of 80% or more against ultraviolet rays. Specifically, referring to 15 (a), the liquid-transmissive thermoplastic resin 50 having a transmittance of 80% or more to ultraviolet rays 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 a material that is hard to some extent is preferable so as to maintain the shape of the liquid transparent thermoplastic resin 50 having a transmittance of 80% or more. 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. 15 (b), the substrate 40 for preliminary encapsulant formed of a solid by heat curing is formed. The substrate 40 for the preliminary encapsulant may be formed by reducing the volume of the liquid transparent thermoplastic resin 50 having a transmittance of 80% or more to ultraviolet rays by 50% or more and preferably 90% or more by a thermosetting process. That is, the solvent is volatilized in the liquid light-transmitting thermoplastic resin 50 to solidify the solvent is volatilized because the volume is greatly reduced.

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. 15 (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. 14H, 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. 14I, 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. 14 (j), the preliminary encapsulant 4 is cut along the cutting line 39 so as to have each groove 38.

16 is a view showing a problem in the case of forming an encapsulant using a liquid transparent light-transmitting thermoplastic resin having a transmittance of 80% or more of the conventional ultraviolet.

When the encapsulant is directly formed using a liquid translucent thermoplastic resin having a transmittance of 80% or more to ultraviolet rays, the volume of the liquid translucent thermoplastic resin applied when thermosetting to cure the liquid translucent thermoplastic resin is about 90%. Since the abnormality is reduced, in order 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. 16 (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, and light extraction efficiency may be reduced, thereby reducing reliability. 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, thereby reducing light extraction efficiency. have.

In addition, referring to FIG. 16B, bubbles B and bubbles may be generated in the encapsulant 22b by repeatedly applying the liquid-transmissive thermoplastic resin and thermosetting. That is, the coating and thermosetting processes are repeated to form the encapsulant 22b into a hemispherical convex lens shape, and the cured encapsulant 22b is cured repeatedly, thereby applying a liquid-transparent thermoplastic resin and a 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.

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

Before the process of FIG. 12 (b), that is, before placing the preliminary encapsulant 4 to surround the semiconductor light emitting device chip 20, referring to FIG. 17 (a), a liquid-transmissive light having a transmittance of 80% or more against ultraviolet rays The thermoplastic resin is applied to form a liquid resin layer 60. At this time, the liquid-transmissive thermoplastic resin having a transmittance of 80% or more to ultraviolet rays is the semiconductor light emitting device chip 62 through the second transfer part 61 performing the same function as the first transfer part 51 shown in FIG. ) To cover.

Next, referring to FIG. 17B, the encapsulant layer 63 is formed by thermosetting the liquid resin layer 60. The encapsulant layer 63 may be formed by volatilizing a solvent by a thermosetting process to reduce the volume by 50% or more, preferably 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. 17 (c), the preliminary encapsulant 64 is placed on the encapsulant layer 63 to form the encapsulant 22. 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 is a translucent thermoplastic that has a transmittance of 80% or more and is less susceptible to UV degradation.

 18 is a view illustrating still another 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 shown in FIG. 18A, first, an external substrate 74 having a portion of an upper surface exposed is prepared. The outer substrate 74 includes a base 741, a conductive layer 742, an insulating layer 743, and a protective layer 745. In this case, the prevention layer 745 and the conductive layer 742 may be formed at the same time, but may be formed through a separate process. In this case, the insulating layer 743 may be omitted. In the case of the prevention layer 745, a groove penetrating the base 741 is processed with a laser, and then a seed metal is deposited using a sputter. Thereafter, the conductive layer 742 is formed by plating after forming a pattern using a dry photoreist film. When forming the conductive layer 742 through plating, the prevention layer 745 may be simultaneously formed.

The outer substrate 74 has an insulating layer 743 formed between the plurality of conductive layers 742 and the plurality of conductive layers 742 on the base 741, and the upper surface of the base 741 around the prevention layer 745. Is exposed. At this time, the base 741 of the portion corresponding to the region where the reflective layer 744 is to be formed is exposed.

Next, as shown in FIG. 18B, the reflective layer 744 is formed on the exposed base 741 using a reflective material. The reflective layer 744 is spaced apart from each other by the first reflective layer 7440 and the prevention layer 745 formed corresponding to the lower surface of the encapsulant 72 and is not covered by the encapsulant 72. 7441).

The first reflective layer 7440 and the second reflective layer 7501 may be simultaneously formed of the same material, but are not limited thereto.

For example, when the semiconductor light emitting device chip 70 emits ultraviolet rays (UV), the first reflective layer 7440 positioned on the side surface of the semiconductor light emitting device chip 70 may be discolored by ultraviolet rays. It is made of white silicon that maintains reflectivity and is insulative, and is located at a predetermined distance from the first reflective layer 7440 and the semiconductor light emitting device chip 70, thereby less affecting ultraviolet rays than the first reflective layer 7440. The second reflective layer 7501 may be made of silver (Ag) or a metal material of aluminum.

Next, as shown in FIG. 18C, the electrode 702 of the semiconductor light emitting device chip 70 is mounted on the outer substrate 74 so as to be electrically connected to the conductive layer 742 of the outer substrate 74. do. In this example, a flip chip is suitable as the semiconductor light emitting device chip 70, but it does not exclude a lateral chip or a vertical chip.

Next, as shown in FIG. 18D, an encapsulant 72 is formed to surround the semiconductor light emitting device chip 70. In this case, the shape of the encapsulant 72 may have a hemispherical convex lens shape, but is not limited thereto.

When the encapsulant 72 is formed, the encapsulant 72 is not formed beyond the encapsulation layer 745 due to the surface tension between the encapsulant 72 and the barrier layer 745.

The encapsulant 72 is cured so that the semiconductor light emitting device chip 70 and the external substrate 74 are integrally coupled by the encapsulant 72. Heat treatment and / or drying to cure the encapsulant 72 may be performed at a temperature of 102 ° C. to 170 ° C. for about 1 hour to 5 hours. The above-described heat treatment and / or drying temperature and time prevents the encapsulant 72 from having a uniform surface and thickness, and prevents bubbles from forming in the encapsulant 72, and the semiconductor light emitting device chip 70 and the external substrate 74. It is limited to be able to be formed with a stable bond or limited, but is not limited thereto. In addition, when the encapsulant 72 is formed of a material having a large volume change during the curing process, the encapsulant 72 may be formed using the preliminary encapsulant illustrated in FIG. 12. 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 the range that can be easily changed by those skilled in the art.

19 is a view illustrating another example of a semiconductor light emitting device according to the present disclosure.

The semiconductor light emitting device 8 is substantially the same as the semiconductor light emitting device 1 described in FIG. 4 except that the reflective layer 844 has only the first reflective layer 844 without the second reflective layer.

20 illustrates another example of a semiconductor light emitting device according to the present disclosure.

The semiconductor light emitting element 9 is substantially the same as the semiconductor light emitting element 1 described in FIG. 4 except that there is no reflective layer.

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 ultraviolet rays 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; And an outer substrate having a base and a conductive layer electrically connected to the electrodes of the semiconductor light emitting device chip, wherein the plane of the outer substrate in contact with the lower surface of the encapsulant is smaller than the plane of the outer substrate not in contact with the lower surface of the encapsulant. Semiconductor light emitting device.

(2) A semiconductor light emitting device, wherein the surface of the conductive layer that is located inside the bag and reflects ultraviolet rays is formed of a material having an ultraviolet reflectance of less than 90%.

(3) A semiconductor light emitting device, wherein the surface of the conductive layer that is located inside the bag and reflects ultraviolet rays is formed of a material having an ultraviolet reflectance of 40% or less.

(4) A semiconductor light emitting element, which is formed inside Au and has one surface of a conductive layer that reflects ultraviolet rays.

(5) The external substrate includes a prevention layer formed in a closed circuit form at a predetermined distance away from the conductive layer, and the lower surface of the encapsulant contacts the upper surface of the prevention layer.

(6) A semiconductor light emitting element, which is located inside the bag and is formed of a material having one surface of an anti-reflective layer that reflects ultraviolet rays with an ultraviolet reflectance of 40% or less.

(7) A semiconductor light emitting device, which is formed inside a bag and is formed of the same metal material on one surface of the conductive layer and the prevention layer that reflects ultraviolet rays.

(8) The encapsulant is a semiconductor light emitting element formed of a thermoplastic resin having a transmittance of 80% or more against ultraviolet rays.

(9) A semiconductor light emitting device in which a thermoplastic resin has a volume of 90% or more in a thermosetting step of solidifying in a liquid phase.

(10) The encapsulant is a semiconductor light emitting element having a semicircular lens shape.

(11) The semiconductor light emitting device chip is a flip chip, the flip chip emits UV-C, the encapsulant has a lens shape formed of a thermoplastic resin having an ultraviolet transmittance of 80% or more, and the upper part of the conductive layer has a reflectance to UV-C. The semiconductor light emitting device is formed of less than 90% of the material, the electrode of the semiconductor light emitting chip is electrically coupled with the upper portion of the conductive layer.

According to the present disclosure, a semiconductor light emitting device having a high ultraviolet extraction efficiency and a high bonding force between the semiconductor light emitting device chip and the conductive layer can be obtained.

According to the present disclosure, in the reflective layer formed on the upper surface of the external substrate on which the semiconductor light emitting device chip is mounted, the reflective layer is formed of aluminum (Al) or white silicon, so that semiconductor light emission is more than that of silver (Ag). Since discoloration is prevented by ultraviolet rays emitted from the device chip 10 and high reflectivity is maintained, a semiconductor light emitting device having improved reliability can be obtained.

According to the present disclosure, it is possible to obtain a semiconductor light emitting device which prevents the encapsulant from being formed over the antiblocking layer by the prevention layer on the external substrate during encapsulation curing.

According to the present disclosure, the diameter of the encapsulant is controlled even when the reflective surface of the external substrate (eg, the upper surface of the conductive layer and the prevention layer) which is located inside the encapsulant and is formed of a material having a reflectance of 90% or less against ultraviolet rays. Thus, a semiconductor light emitting device having a ΔPo value of 50% or more can be obtained. Furthermore, even when the reflective surface of the external substrate (eg, the upper surface of the conductive layer and the prevention layer) that is located inside the encapsulant and is formed of a material having a reflectivity of UV of 90% or less, the material having a reflectance of UV of 90% or more When compared with the case of using the semiconductor light emitting device having a difference of ΔPo value within 5% can be obtained.

 In the present disclosure, in a semiconductor light emitting device that emits ultraviolet light having a short wavelength, it is preferable to use a material (eg, Al) having a high reflectance with respect to the ultraviolet ray in terms of reflection on the reflection surface positioned inside the encapsulant and reflecting the ultraviolet ray. Among the materials having high reflectance to ultraviolet rays, there is a problem that the bonding strength is poor when bonding the electrode of the semiconductor light emitting device chip by a method such as soldering or eutectic bonding. On the contrary, when the electrode is bonded to the semiconductor light emitting device chip by a method such as soldering or eutectic bonding, there is a problem in that a material having a good bonding strength has a low reflectance against ultraviolet rays. Applicants have similar light output efficiencies to those using high-reflective materials, even though materials with good bonding strength are used when bonding the electrodes of semiconductor light-emitting chips with soldering or eutectic bonding, in spite of their low reflectance to UV light. It was found that the diameter size of the lower surface of the encapsulant was reduced in such a way that it could be obtained. Furthermore, a barrier layer structure was added to adjust the diameter of the bottom surface of the encapsulant. Furthermore, when the thermoplastic resin is used to obtain a lens having a desired shape by adjusting the diameter of the lower surface of the encapsulant, the thermoplastic resin, which does not easily deteriorate to ultraviolet rays, of the thermoplastic resin is not preferable due to the large volume change in forming the encapsulant. The encapsulant was used to allow the use of a thermoplastic resin having a large volume change but little degradation to ultraviolet rays.

Semiconductor light emitting device: 1, 8, 9, 700
Semiconductor light emitting chip: 10, 10a, 20, 62, 70, 750
Encapsulant: 12, 22, 72, 770
Outer substrate: 14, 24, 74
Protective layer: 145, 243, 745
Reflective layer: 144, 244, 744, 844

Claims (11)

In a semiconductor light emitting device,
A semiconductor light emitting device chip comprising a plurality of semiconductor layers including an active layer for generating ultraviolet rays 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; And,
And an outer substrate including a base and a conductive layer electrically connected to electrodes of the semiconductor light emitting device chip.
A semiconductor light emitting element in which the plane of the outer substrate in contact with the lower surface of the encapsulation material is smaller than the plane of the outer substrate not in contact with the lower surface of the encapsulant. The method of claim 1,
A semiconductor light emitting device, which is formed inside a bag and has one surface of a conductive layer that reflects ultraviolet rays, is formed of a material having an ultraviolet reflectance of less than 90%. The method of claim 2,
A semiconductor light emitting device, wherein the light emitting device is formed of a material having an ultraviolet reflectance of 40% or less on one surface of a conductive layer that reflects ultraviolet rays. The method of claim 3,
A semiconductor light emitting device, which is formed inside an encapsulation layer and has one surface of a conductive layer that reflects ultraviolet rays. The method of claim 1,
The outer substrate includes a prevention layer formed in a closed circuit at a predetermined distance away from the conductive layer,
A semiconductor light emitting element in which the lower surface of the encapsulant contacts the upper surface of the prevention layer. The method of claim 5,
A semiconductor light emitting device, which is disposed inside a bag and is formed of a material having an ultraviolet reflectance of 40% or less on one surface of the anti-reflective layer. The method of claim 6,
A semiconductor light emitting device, which is disposed inside the encapsulation and has one surface of a conductive layer that reflects ultraviolet rays and one surface of a prevention layer formed of the same metal material. The method of claim 1,
The encapsulant is a semiconductor light emitting device formed of a thermoplastic resin having a transmittance of 80% or more against ultraviolet rays. The method of claim 8,
Thermoplastic resin is a semiconductor light emitting device that the volume is reduced by more than 90% in the thermosetting process is solidified in the liquid phase. The method of claim 1,
The encapsulant has a semicircular lens shape. The method of claim 1,
The semiconductor light emitting device chip is a flip chip,
Flip chips emit UV-C,
The encapsulant has a lens shape formed of a thermoplastic resin having an ultraviolet transmittance of 80% or more.
The top of the conductive layer is formed of a material having a reflectance of less than 90% for UV-C,
The electrode of the semiconductor light emitting device chip is a semiconductor light emitting device electrically coupled with the upper portion of the conductive layer.

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