JP2019212871A - Ultraviolet light-emitting element, ultraviolet light-emitting device, and method for joining semiconductor chip and lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the adhesive performance between a lens and a semiconductor chip of an ultraviolet light emitting element in which a light extraction surface of the semiconductor chip is bonded to an incident surface of the lens with an amorphous fluororesin. An ultraviolet light emitting element 1 includes a semiconductor chip 110 that emits ultraviolet light, an ultraviolet transparent lens 120, and a bonding layer 131 that bonds an incident surface 121 and a light extraction surface 110a. The bonding layer 131 is an amorphous fluororesin layer. The adhesive strength between the light extraction surface 110a and the incident surface 121 by the bonding layer 131 is 6 N / mm2 or more and 40 N / mm2 or less in shear strength measured according to EIAJ-ED-4703. [Selection diagram] Figure 1

Description

  The present invention relates to an ultraviolet light emitting element and a method for joining a semiconductor chip and a lens.

For the purpose of improving the light extraction efficiency of the chip-like ultraviolet light-emitting element, it has been proposed to bond a lens to the light extraction surface (the back surface of the substrate on which the element is formed) (for example, Non-Patent Document 1). , See Patent Documents 1 and 2).
Non-Patent Document 1 describes a deep ultraviolet LED using an AlGaN-based nitride semiconductor and also describes that a sapphire polished surface of an LED chip and a lens are directly bonded at room temperature.
Patent Document 1 describes a method of directly attaching a hemispherical lens to an LED die using, for example, a thin layer of a sealant made of silicone oil and / or silicone resin. In the ultraviolet light-emitting element described in Patent Document 1, the plane of the hemispherical lens is larger than the light extraction surface of the LED die, and the thin layer of the sealing agent covers only the light extraction surface of the LED die.

Patent Document 2 describes that an amorphous fluororesin is used to bond a lens to a chip that is an ultraviolet light emitting element. Specifically, it is described that bonding is performed so that the shear strength between the bottom surface of the lens and the light extraction surface of the chip is 1.0 to 5.0 N / mm ² .

JP-T-2017-521872 JP 2016-1111085 A

The 62nd JSAP Spring Meeting, 2015 17-255 2015 (Lecture No. 14p-B1-5)

The joining method of Non-Patent Document 1 has a problem of low mass productivity. In the methods described in Patent Documents 1 and 2, the problem is that the adhesiveness is insufficient.
An object of the present invention is to improve the bonding performance between a lens and a semiconductor chip of an ultraviolet light emitting element in which a light extraction surface of a semiconductor chip is bonded to an incident surface of a lens with an amorphous fluororesin.

In order to solve the above-described problem, the ultraviolet light-emitting device according to the first aspect of the present invention joins a semiconductor chip that emits ultraviolet light, an ultraviolet-transmissive lens, a light extraction surface of the semiconductor chip, and an incident surface of the lens. And an ultraviolet transmissive bonding layer. The bonding layer is an amorphous fluororesin layer, and the adhesive strength between the light extraction surface and the incident surface by the bonding layer is 6 N / mm ² or more and 40 N / mm in terms of shear strength measured according to EIAJ-ED-4703. ² or less.

The second aspect of the present invention is a method for joining a semiconductor chip and a lens, and includes the following first step, second step, third step, fourth step, and fifth step.
The first step is a step of forming a liquid layer of a sealing material including a thermoplastic amorphous fluororesin and a solvent on a light extraction surface of a semiconductor chip that emits ultraviolet rays.
The second step is a step in which the liquid layer after the first step is heated to uniformly evaporate the solvent from the surface of the liquid layer, so that the liquid layer is formed into a resin layer swelled by surface tension.
The third step is a step of heating the resin layer after the second step to make the resin layer a fluid resin layer having a shape raised by surface tension.
The fourth step is a step of pressing the flat surface of the lens on the fluid resin layer after the third step while heating the semiconductor chip.
In the fifth step, after the fourth step, the heating of the semiconductor chip is stopped and cooled, so that the amorphous fluororesin contained in the sealing material joins between the plane of the lens and the light extraction surface of the semiconductor chip. It is a process of forming a layer.

The ultraviolet light emitting element of the first aspect has high adhesion performance between the lens and the semiconductor chip.
According to the bonding method of the semiconductor chip and the lens of the second aspect, the adhesion property is suppressed by preventing bubbles and wrinkles from entering the bonding layer made of the amorphous fluororesin formed between the lens and the semiconductor chip. Since the bonding strength due to the intermolecular force increases and the adhesion strength between the lens and the semiconductor chip by the amorphous fluororesin layer can be expected to improve.

It is sectional drawing which shows the ultraviolet-ray light-emitting device provided with the ultraviolet light-emitting element of 1st embodiment. It is sectional drawing which shows the semiconductor chip which comprises the ultraviolet light emitting element of 1st embodiment. FIG. 3 is a partially cutaway sectional view showing a state where the semiconductor chip of FIG. 2 is mounted on a package substrate. It is a manufacturing method of the ultraviolet-light-emitting device of FIG. 1, Comprising: It is a figure explaining an example of the joining method of a semiconductor chip and a lens. It is a figure explaining the detail of the method shown in FIG. It is sectional drawing which shows the ultraviolet light emitting element of 2nd embodiment. FIG. 7 is a diagram for explaining an example of a method of manufacturing the ultraviolet light emitting device of FIG. 6 and a method of bonding a semiconductor chip and a lens. FIG. 7 is a diagram for explaining an example of a method of manufacturing the ultraviolet light emitting device of FIG. 6 and a method of bonding a semiconductor chip and a lens. It is sectional drawing which shows the ultraviolet light emitting element of 3rd embodiment. It is sectional drawing which shows the ultraviolet light emitting element of 4th embodiment. It is sectional drawing which shows the ultraviolet light emitting element of 5th embodiment. It is sectional drawing which shows the ultraviolet-ray light-emitting device provided with the ultraviolet light-emitting element of 6th embodiment. It is a manufacturing method of the ultraviolet light-emitting device of FIG. 12, Comprising: It is a figure explaining the method of forming a lens coating layer. It is sectional drawing which shows the ultraviolet light emitting element of 7th embodiment. It is sectional drawing which shows the ultraviolet light emitting element of 8th embodiment.

  Hereinafter, although embodiment of this invention is described, this invention is not limited to embodiment shown below. In the embodiment described below, a technically preferable limitation is made for carrying out the present invention, but this limitation is not an essential requirement of the present invention.

[First embodiment]
〔Constitution〕
An ultraviolet light emitting device 10 shown in FIG. 1 includes an ultraviolet light emitting element 1 and a package substrate (base body) 2, and a first connecting body 3 and a second connecting body 4 that electrically connect the ultraviolet light emitting element 1 and the package substrate 2. Have.
The ultraviolet light emitting element 1 includes a semiconductor chip 110 that emits ultraviolet light, a hemispherical lens 120 made of quartz or sapphire, and a bonding layer 131. The plane (incident surface) 121 of the hemispherical lens 120 is larger than the light extraction surface 110 a of the semiconductor chip 110.
The bonding layer 131 is a layer that bonds the flat surface (incident surface) 121 of the hemispherical lens 120 and the light extraction surface 110 a of the semiconductor chip 100. The bonding layer 131 is an amorphous fluororesin layer, and the shear adhesive strength between the light extraction surface 110a by the bonding layer 131 and the flat surface (incident surface) 121 of the hemispherical lens 120 is 6 N / mm ² or more and 40 N / mm ² or less. .

As shown in FIG. 2, the semiconductor chip 110 includes a substrate 111, a semiconductor layer 112, a first electrode 113, and a second electrode 114. The semiconductor chip 110 can emit UVC having a wavelength of 280 nm or less, for example.
The substrate 111 is, for example, an AlN substrate. The semiconductor layer 112 includes an n-type nitride semiconductor layer (first conductivity type nitride semiconductor layer), a nitride semiconductor light emitting layer, and a p-type nitride semiconductor layer (second conductivity type nitride semiconductor layer). Is the body. The n-type nitride semiconductor layer is, for example, an n-AlGaN layer. The nitride semiconductor light emitting layer is, for example, a layer having a multiple quantum well structure (MQW) including a quantum well layer made of AlGaN and an electron barrier layer made of AlN. The p-type nitride semiconductor layer is, for example, a p-GaN layer. The first electrode 113 is formed on the n-type nitride semiconductor layer, and the second electrode 114 is formed on the p-type nitride semiconductor layer.
The light extraction surface 110a of the semiconductor chip 110 is the back surface of the substrate 111 (the surface opposite to the surface 111a on which the semiconductor layer 112 is formed).

〔Production method〕
The ultraviolet light emitting device 10 shown in FIG. 1 can be manufactured by the following method.
First, the package substrate 2 in which the third electrode 21 and the fourth electrode 22 are formed on the surface 20 facing the semiconductor chip 110 is prepared. Next, the third electrode 21 of the package substrate 2 and the first electrode 113 of the semiconductor chip 110 are connected by the first connection body 3, and the fourth electrode 22 of the package substrate 2 and the second electrode 114 of the semiconductor chip 110 are connected by the second connection. Each of the connectors 4 is electrically connected.
That is, the semiconductor chip 110 is flip-chip mounted on the package substrate 2 to obtain the state shown in FIG. As a connection method, for example, an ultrasonic bonding method using metal bumps as the first connection body 3 and the second connection body 4 is employed.

Next, the hemispherical lens 120 is bonded to the light extraction surface 110 a of the semiconductor chip 110. This joining method will be described with reference to FIGS.
First, as shown in FIG. 4A, the package substrate 2 on which the semiconductor chip 110 is mounted is placed on the hot plate 5. At this stage, the hot plate 5 is not switched on.
Next, as illustrated in FIG. 4B, a liquid layer 6 of a sealing material including a thermoplastic amorphous fluororesin and a solvent is formed on the entire light extraction surface 110 a of the semiconductor chip 110. This corresponds to the first step.

Next, the hot plate 5 is turned on to heat the package substrate 2, and the liquid layer 6 formed in the first step is heated, thereby evaporating the solvent contained in the liquid layer 6 and rising by the surface tension. The resin layer 61 having a different shape is formed. This corresponds to the second step. FIG. 4C shows this state. In this 2nd process, the content rate of the solvent contained in the resin layer 61 shall be 1 mass% or less by leaving it to stand at 120-200 degreeC for 0.5 to 2 hours, for example.
Next, the set temperature of the hot plate 5 is raised, the temperature of the resin layer 61 after the second step is raised to about 260 to 270 ° C., and held for a predetermined time. This corresponds to the third step. As a result, the fluidity of the resin layer 61 is increased, and the fluidity resin layer 62 having a shape raised by the surface tension is formed on the entire surface of the light extraction surface 110a. FIG. 4D shows this state.
Next, the flat surface 121 of the hemispherical lens 120 is pressed onto the fluid resin layer 62 while keeping the semiconductor chip 110 heated without changing the set temperature of the hot plate 5. This corresponds to the fourth step. FIG. 4E shows this state.

Next, the hot plate 5 is turned off to stop the heating of the semiconductor chip 110 and leave it to cool. This step corresponds to the fifth step. As a result, a bonding layer 131 as shown in FIG. 1 is formed.
During the heating in the second step, the solvent is uniformly evaporated from the surface of the liquid layer 6 as indicated by an arrow in FIG. Thereby, after a 3rd process, as shown in FIG.5 (b), it is suppressed that a bubble and a wrinkle are made in the fluid resin layer 62. FIG.
In the fourth step, the raised fluid resin layer 62 is crushed by the flat surface 121 of the hemispherical lens 120 as shown in FIG. Therefore, bubbles and wrinkles are prevented from entering the fluid resin layer 62 in the fourth step.

As a result, after cooling in the fifth step, the hemispherical lens 120 is bonded to the light extraction surface 110a of the semiconductor chip 110 by the bonding layer 131 that is an amorphous fluororesin layer.
The thickness of the bonding layer 131 is 0.1 μm or more and 1.0 mm or less.
As a sealing material containing a thermoplastic amorphous fluororesin and a solvent, “Cytop (registered trademark)” manufactured by Asahi Glass can be used. For example, the resin contained in Cytop (registered trademark) CTX-809SP2 is an amorphous fluororesin having a perfluoroalkyl group. This resin has a thickness of 50 μm, a transmittance of 98% at a wavelength of 265 nm, and a transmittance of 90% or more in the entire range from 210 nm to less than 300 nm.

(Action, effect)
Since the ultraviolet light emitting device 10 of the first embodiment is manufactured by the above-described method, it is possible to prevent bubbles and wrinkles from entering the bonding layer 131. Therefore, the bonding layer 131 that is an amorphous fluororesin layer is used. The bonding strength between the light extraction surface 110a of the semiconductor chip 110 and the flat surface (incident surface) 121 of the hemispherical lens 120 is increased. That is, the shear bond strength can be made 6 N / mm ² or more and 40 N / mm ² or less.

[Second Embodiment]
The ultraviolet light emitting device 10A of the second embodiment shown in FIG. 6 is the same as the ultraviolet light emitting device 10 of the first embodiment except for the following points.
The ultraviolet light emitting element 1 </ b> A includes a semiconductor chip 110 that emits ultraviolet light, a hemispherical lens 120 made of quartz or sapphire, and an amorphous fluororesin layer 130.
The amorphous fluororesin layer 130 is formed by continuously forming a bonding layer 131, an incident surface coating layer 132, and a chip side surface coating layer 133. The incident surface coating layer 132 is a layer that covers all of the outer edge portion (portion not facing the light extraction surface 110a) 121a of the flat surface (incident surface) 121 of the hemispherical lens 120. The chip side surface coating layer 133 is a layer that covers the side surface 110 b of the semiconductor chip 110. That is, the incident surface coating layer 132 is an amorphous fluororesin layer formed so as to be connected to the bonding layer 131, and the chip side surface coating layer 133 is formed continuously from the bonding layer 131 and the incident surface coating layer 132. An amorphous fluororesin layer.

The ultraviolet light emitting device 10A shown in FIG. 6 can be manufactured by the method shown in FIG. 7 or the method shown in FIG.
In the method shown in FIG. 7, first, as shown in FIG. 7 (a), the hemispherical lens 120 is placed on the plane 121 with the plane 121 facing upward, and the plane 121 is held horizontally. The liquid layer 6 of the sealing material containing the amorphous fluororesin and the solvent is formed. Next, as shown in FIG. 7B, the hemispherical lens 120 is heated to uniformly evaporate the solvent of the liquid layer 6 from the surface of the liquid layer 6, and the liquid layer 6 is raised by the surface tension. The resin layer 61 is made. In this step, for example, the content of the solvent contained in the resin layer 61 is set to 1% by mass or less by leaving it at 120 to 200 ° C. for 0.5 to 2 hours.

Next, the heating temperature of the hemispherical lens 120 is raised, the temperature of the resin layer 61 is raised to about 260 to 270 ° C., and is held for a predetermined time. Thereby, the fluid resin layer 62 having a shape raised by the surface tension is formed on the entire surface of the plane 121. FIG. 7C shows this state.
Next, as shown in FIG. 7D, the package substrate 2 on which the semiconductor chip 110 is mounted is placed on the hot plate 5 in advance, and the temperature of the semiconductor chip 110 is set to about 260 to 270 ° C. on the hot plate 5. Keep it raised. In this state, the hemispherical lens 120 is placed on the light extraction surface 110a of the semiconductor chip 110 so that the fluid resin layer 62 is in contact therewith. Next, the hemispherical lens 120 is pressed so that a part of the fluid resin layer 62 reaches the side surface 110 b of the semiconductor chip 110. FIG. 7E shows this state.
Next, the hot plate 5 is turned off to stop the heating of the semiconductor chip 110 and leave it to cool. As a result, an amorphous fluororesin layer 130 as shown in FIG. 6 is formed.

  The method shown in FIG. 8 is substantially the same as the manufacturing method of the ultraviolet light emitting device 10 of the first embodiment shown in FIG. 4, but in the step of FIG. 8B corresponding to FIG. Is formed more than the method of FIG. 8E corresponding to FIG. 4E, the flat surface 121 of the hemispherical lens 120 is pressed onto the fluid resin layer 62 so that a part of the fluid resin layer 62 is formed on the semiconductor chip 110. It protrudes from the light extraction surface 110 a and reaches the peripheral edge 121 a of the flat surface 121 and the side surface 110 b of the semiconductor chip 110. As a result, the incident surface coating layer 132 and the chip side surface coating layer 133 are continuously formed on the bonding layer 131.

[Third embodiment]
The ultraviolet light emitting element 1B of the third embodiment shown in FIG. 9 is the same as the ultraviolet light emitting element 1A of the second embodiment except for the following points.
The chip side surface coating layer 133 is not provided, but the rising surface coating layer 134 that covers the rising surface 123 from the incident surface 121 of the hemispherical lens 120 is provided. The rising surface coating layer 134 is continuous with the incident surface coating layer 132 through the coupling layer 135.
That is, the amorphous fluororesin layer 130A included in the ultraviolet light emitting element 1B includes a bonding layer 131, an incident surface coating layer 132 that is continuous with the bonding layer 131, a coupling layer 135 that is continuous with the incident surface coating layer 132, and a coupling layer. 135, and a rising surface coating layer 134 that is continuous with 135.

The ultraviolet light emitting element 1 </ b> B of the third embodiment has the rising surface coating layer 134 formed continuously with the incident surface coating layer 132, so that the amorphous fluororesin layer is compared with the case where it does not have this. The bonding strength between the light extraction surface 110a of the semiconductor chip 110 and the hemispherical lens 120 by 130A is increased.
When the liquid layer 6 is formed on the flat surface 121 by the method shown in FIG. 7 of the ultraviolet light emitting element 1A of the second embodiment, the rising surface coating layer 134 is formed so that a part of the liquid layer 6 rises from the flat surface 121. It can be formed by forming the resin layer 61 after maintaining this state, and then forming the fluid resin layer 62.

[Fourth embodiment]
The ultraviolet light emitting element 1C of the fourth embodiment shown in FIG. 10 is the same as the ultraviolet light emitting element 1A of the second embodiment except for the following points.
A part of the side surface 111b of the substrate 111 of the semiconductor chip 110 is a rough surface 111c. The portion which is the rough surface 111c is a portion close to the light extraction surface 110a. Only the portion that is the rough surface 111c is covered with the chip side surface coating layer 133A. The arithmetic average roughness Ra of the rough surface 111c is not less than 100 nm and not more than 10 μm.

Examples of the method of forming the rough surface 111c include a method of directly using irregularities formed by laser scribing, dicing, or breaking when the semiconductor chip 110 is cut out from a wafer, and a method of performing a blast process.
In the ultraviolet light emitting element 1C of the fourth embodiment, since the portion that is the rough surface 111c of the semiconductor chip 110 is covered with the chip side surface coating layer 133A, the chip side surface coating layer is provided without providing the rough surface 111c. Compared to the case, the bonding strength of the chip side surface covering layer 133A to the semiconductor chip 110 is increased. Accordingly, the bonding strength between the light extraction surface 110a of the semiconductor chip 110 and the hemispherical lens 120 by the amorphous fluororesin layer 130B is increased.

[Fifth embodiment]
The ultraviolet light emitting element 1D of the fifth embodiment shown in FIG. 11 is the same as the ultraviolet light emitting element 1A of the second embodiment except for the following points.
A part of the peripheral portion 121a of the flat surface 121 of the hemispherical lens 120 is a rough surface 121b. The portion which is the rough surface 121b of the peripheral edge portion 121a is a portion close to the surface facing the light extraction surface 110a. The rising surface 123 covered with the rising surface coating layer 134 is also a rough surface 123a. The arithmetic average roughness Ra of these rough surfaces 121b and 123a is not less than 100 nm and not more than 10 μm.

Examples of the method of forming the rough surfaces 121b and 123a include a method in which a part of the peripheral edge 121a of the flat surface 121 of the hemispherical lens 120 and the rising surface 123 are subjected to blasting.
In the ultraviolet light emitting element 1D of the fifth embodiment, the rough surfaces 121b and 123a are provided, so that the bonding strength between the peripheral portion 121a of the plane 121 and the incident surface coating layer 132, and the rising surface 123 and the rising surface coating layer 134 are Is higher than the ultraviolet light emitting element 1A of the second embodiment. That is, the end of the amorphous fluororesin layer 130 </ b> C is difficult to peel off from the hemispherical lens 120.

[Sixth embodiment]
〔Constitution〕
The ultraviolet light emitting device 10B of the sixth embodiment shown in FIG. 12 is the same as the ultraviolet light emitting device 10A of the second embodiment except for the following points.
The ultraviolet light emitting element 1 </ b> E constituting the ultraviolet light emitting device 10 </ b> B has a lens coating layer 136 that covers the hemispherical surface (entire surface other than the incident surface) 125 of the hemispherical lens 120. The lens coating layer 136 is continuous with the incident surface coating layer 132 through the coupling layer 135.
That is, the amorphous fluororesin layer 130D included in the ultraviolet light emitting element 1E includes a bonding layer 131, an incident surface coating layer 132 continuous with the bonding layer 131, and a chip side surface coating continuous with the bonding layer 131 and the incident surface coating layer 132. The layer 133 includes a coupling layer 135 that is continuous with the incident surface coating layer 132, and a lens coating layer 136 that is continuous with the coupling layer 135. Further, the entire surface of the hemispherical lens 120 is covered with an amorphous fluororesin layer (a continuously formed bonding layer 131, incident surface coating layer 132, coupling layer 135, and lens coating layer 136).

〔Production method〕
The ultraviolet light emitting device 10B of FIG. 12 can be manufactured by the following method.
First, the hemispherical lens 120 is joined to the light extraction surface 110a of the semiconductor chip 110 in the state shown in FIG. 3 by the method shown in FIG. 7 or 8 described in the method for manufacturing the ultraviolet light emitting device 10A of the second embodiment. Thereby, the amorphous fluororesin layer 130 is formed.
Next, as shown in FIG. 13A, the same liquid layer 6 as that used when forming the amorphous fluororesin layer 130 is applied to the highest portion of the hemispherical surface 125 of the hemispherical lens 120. If left as it is, the liquid layer 6 gradually descends and the area covering the hemispherical surface 125 of the hemispherical lens 120 increases as shown in FIG. As shown in FIG. 13C, when the entire hemispherical surface 125 and the outer peripheral surface 130a of the amorphous fluororesin layer 130 are covered with the liquid layer 6, the solvent in the liquid layer 6 is evaporated. Let

As a result, the lens coating layer 136 is formed on the hemispherical surface 125, and the lens coating layer 136 is coupled to the amorphous fluororesin layer 130 by the coupling layer 135. As a result, as shown in FIG. 12, an amorphous fluororesin layer 130D in which the bonding layer 131, the incident surface coating layer 132, and the lens coating layer 136 are continuous is formed. That is, the entire surface of the hemispherical lens 120 is covered with the amorphous fluororesin layer 130D.
The ultraviolet light emitting device 10B according to the sixth embodiment includes the lens coating layer 136 formed continuously with the incident surface coating layer 132, and thus compared with the ultraviolet light emitting device 10A according to the second embodiment that does not include the lens coating layer 136. The bonding strength between the light extraction surface 110a of the semiconductor chip 110 and the hemispherical lens 120 by the amorphous fluororesin layer 130D is increased.

[Seventh embodiment]
The ultraviolet light emitting element 1F of the seventh embodiment shown in FIG. 14 is the same as the ultraviolet light emitting element 1E of the sixth embodiment except for the following points.
The coverage of the side surface of the semiconductor chip 110 by the chip side surface coating layer 133B is smaller than the chip side surface coating layer 133 of the ultraviolet light emitting element 1E of the sixth embodiment. The chip side surface coating layer 133 </ b> B is formed over the entire surface of the incident surface coating layer 132 and the entire surface of the coupling layer 135.

[Eighth embodiment]
The ultraviolet light emitting device 10C of the eighth embodiment shown in FIG. 15 is the same as the ultraviolet light emitting device 10B of the sixth embodiment except for the following points.
The chip side surface coating layer 133 </ b> C is formed over the entire surface of the incident surface coating layer 132 and the entire surface of the coupling layer 135. The chip side surface covering layer 133 </ b> C has an outer layer 137 that reaches the package substrate 2 continuously. An inner layer 138 exists in a space formed by the surface 110 d opposite to the light extraction surface 110 a of the semiconductor chip 110, the package substrate 2, the first connection body 3, and the second connection body 4.

That is, in the ultraviolet light emitting device 10C, the bonding layer 131, the incident surface coating layer 132, the coupling layer 135, and the lens coating layer 136 are continuously formed as an amorphous fluororesin layer 130F that covers the entire surface of the hemispherical lens 120. Have Further, the chip side surface coating layer 133C is continuous with the incident surface coating layer 132 and the coupling layer 135 of the amorphous fluororesin layer 130F.
In the ultraviolet light emitting device 10C, all of the surfaces constituting the space formed by the semiconductor chip 110, the hemispherical lens 120, the package substrate 2, the first connection body 3, and the second connection body 4 are amorphous fluororesins. Layers (incident surface coating layer 132, chip side surface coating layer 133C, and outer layer 137 formed in succession) are covered. Further, all the surfaces constituting the space formed by the semiconductor chip 110, the package substrate 2, the first connection body 3 and the second connection body 4 are covered with an amorphous fluororesin layer (inner layer 138). Yes.

The ultraviolet light emitting device 10C can be manufactured by the following method. First, similarly to the ultraviolet light emitting device 10B of the sixth embodiment, the hemispherical lens 120 is bonded to the light extraction surface 110a of the semiconductor chip 110 by the method shown in FIG. 7 or FIG. Next, a sealing material including a thermoplastic amorphous fluororesin and a solvent outside the semiconductor chip 110, the first connection body 3, and the second connection body 4 between the hemispherical lens 120 and the package substrate 2. In addition, the same liquid layer is filled between the semiconductor chip 110 and the package substrate 2, and then the solvent of these liquid layers is evaporated.
The ultraviolet light emitting device 10C of the eighth embodiment has a higher bonding strength between the light extraction surface 110a of the semiconductor chip 110 and the hemispherical lens 120 by the amorphous fluororesin layer than the ultraviolet light emitting device 10B of the sixth embodiment. Become.

[Remarks]
In the above embodiment, after mounting the semiconductor chip 110 on the package substrate 2, the ultraviolet light emitting device is manufactured by bonding the hemispherical lens 120 to the light extraction surface 110 a of the semiconductor chip 110. However, after the hemispherical lens 120 is bonded to the light extraction surface 110a of the semiconductor chip 110 before being mounted on the package substrate 2 by the method shown in FIG. 4, FIG. 7, or FIG. 8, the semiconductor chip 110 is mounted on the package substrate 2. You can also This mounting can be performed in the same manner as the semiconductor chip 110 to which the hemispherical lens 120 is not bonded.
As the amorphous fluororesin that joins the lens and the substrate, one having a non-reactive terminal functional group that does not exhibit a binding property to the metal constituting the first electrode 13 and the second electrode 14 of the semiconductor light emitting device is used. It is more preferable.

[Example 1]
In Example 1, the semiconductor light emitting device 10 having the structure shown in FIG. 1 was produced.
The substrate 111 of the semiconductor chip 110 is an AlN substrate, and the hemispherical lens 120 is bonded to the light extraction surface 110a of the semiconductor chip 110 which is the back surface of the substrate 111 by the method shown in FIG. The light extraction surface 110a is a square having a side of 0.9 mm, and the diameter of the flat surface 121 of the hemispherical lens 120 is a circle of 2 mm.
First, the semiconductor chip 110 was flip-chip mounted on the package substrate 2 and placed on the hot plate 5 to obtain the state shown in FIG. Next, a liquid layer 6 is formed on the entire light extraction surface 110a of the semiconductor chip 110 by applying a liquid obtained by diluting CYTOP (registered trademark) CTX-809SP2 with a dedicated diluent solvent, thereby forming the liquid layer 6 shown in FIG. ).

In this state, the hot plate 5 was turned on to set the set temperature to 200 ° C., and the package substrate 2 was heated at 200 ° C. for 0.5 hour. As a result, the liquid layer 6 is heated, and the solvent is uniformly evaporated from the surface of the liquid layer 6 to form a resin layer 61 having a raised shape due to surface tension, as shown in FIG. The rate became 1% by mass or less.
Next, the set temperature of the hot plate 5 was raised to raise the temperature of the resin layer 61 to about 260 ° C. and held for 0.5 hours. As a result, the resin layer 61 was heated to increase the fluidity, and a fluid resin layer 62 having a shape raised by the surface tension was obtained. Air bubbles and wrinkles did not occur in the fluid resin layer 62.

Next, the flat surface 121 of the hemispherical lens 120 was pressed onto the fluid resin layer 62 while maintaining the heated state of the semiconductor chip 110 without changing the set temperature of the hot plate 5.
Next, the hot plate 5 was turned off to stop the heating of the semiconductor chip 110 and let it stand for cooling. As a result, the bonding layer 131 which is an amorphous fluororesin layer free from bubbles and wrinkles was formed. That is, the hemispherical lens 120 and the semiconductor chip 110 were joined with an amorphous fluororesin layer having no bubbles or wrinkles.
The adhesive strength between the hemispherical lens 120 of the obtained semiconductor light emitting device 10 and the semiconductor chip 110 was measured by a method defined in EIAJ-ED-4703. Specifically, five or more samples of the semiconductor light emitting device 10 are produced by the above-described method, and the shear strength is measured for each sample by moving the hemispherical lens 120 laterally from the semiconductor chip 110 with a tool with a sensor. The highest measured value was taken as the adhesive strength. As a result, the adhesive strength of Example 1 was 13.6 N / mm ² .

[Example 2]
In Example 2, the semiconductor light emitting device 10B having the structure shown in FIG. 12 was produced.
As the first step, the same hemispherical lens 120 as in Example 1 and the package substrate 2 on which the semiconductor chip 110 was mounted were used, and the hemispherical lens 120 was bonded to the light extraction surface 110a of the semiconductor chip 110 by the method shown in FIG.
In this step, first, the hemispherical lens 120 is placed with the plane 121 facing upward, and the plane 121 is held horizontally, and Cytop (registered trademark) CTX-809SP2 is placed on the plane 121 with a dedicated diluent solvent. By applying the diluted liquid, the state shown in FIG. That is, the liquid layer 6 was formed on the flat surface 121.

Next, the hemispherical lens 120 was heated at 200 ° C. for 0.5 hour. As a result, the liquid layer 6 is heated, and the solvent is uniformly evaporated from the surface of the liquid layer 6, resulting in a resin layer 61 having a shape raised by surface tension, as shown in FIG. 7B. The rate became 1% by mass or less.
Next, the heating temperature of the hemispherical lens 120 was raised to raise the temperature of the resin layer 61 to about 260 ° C. and held for 0.5 hour. Thereby, the resin layer 61 was heated and fluidity | liquidity became high, and as shown in FIG.7 (c), it became the fluidity | liquidity resin layer 62 of the shape raised by surface tension. Air bubbles and wrinkles did not occur in the fluid resin layer 62.

Before forming the liquid layer 6 on the hemispherical lens 120, the package substrate 2 on which the semiconductor chip 110 is flip-chip mounted is placed on the hot plate 5, and the temperature of the semiconductor chip 110 is maintained at 260 ° C. with the hot plate 5. I kept it.
Next, the hemispherical lens 120 having the fluid resin layer 62 formed on the flat surface 121 is brought into contact with the fluid resin layer 62 on the light extraction surface 110a of the semiconductor chip 110 thus heated. The state shown in FIG. Next, the hemispherical lens 120 was pressed so that a part of the fluid resin layer 62 reached the side surface of the semiconductor chip 110 to obtain the state shown in FIG.

Next, the hot plate 5 was turned off to stop the heating of the semiconductor chip 110 and let it stand for cooling. As a result, the amorphous fluororesin layer 130 in which the bonding layer 131, the incident surface coating layer 132, and the chip side surface coating layer 133 are continuous was formed, and no bubbles or wrinkles were generated in the amorphous fluororesin layer 130. That is, the hemispherical lens 120 and the semiconductor chip 110 were joined with an amorphous fluororesin layer having no bubbles or wrinkles.
As the next step, the lens coating layer 136 was formed by the method shown in FIG.
In this step, first, as shown in FIG. 13A, the same liquid layer 6 as that used for forming the amorphous fluororesin layer 130 is formed on the highest portion of the hemispherical surface 125 of the hemispherical lens 120. Applied. As shown in FIG. 13C, when the entire hemispherical surface 125 and the outer peripheral surface 130a of the amorphous fluororesin layer 130 are covered with the liquid layer 6, as shown in FIG. 6 was heated at 200 ° C. for 0.5 hour to evaporate the solvent of the liquid layer 6.

As a result, the lens coating layer 136 is formed on the hemispherical surface 125, and the lens coating layer 136 is bonded to the amorphous fluororesin layer 130 by the coupling layer 135. As a result, as shown in FIG. 12, an amorphous fluororesin layer 130D in which the bonding layer 131, the incident surface coating layer 132, and the lens coating layer 136 are continuous was formed. That is, the entire surface of the hemispherical lens 120 was covered with the amorphous fluororesin layer 130D.
The adhesive strength between the hemispherical lens 120 of the obtained semiconductor light emitting device 10B and the semiconductor chip 110 was measured by the same method as in Example 1. As a result, it was 24.1 N / mm ² .

[Comparative Example 1]
In Comparative Example 1, a semiconductor light emitting device having the same structure as that of the semiconductor light emitting device 10 shown in FIG.
Using the same hemispherical lens 120 as in Example 1 and the package substrate 2 on which the semiconductor chip 110 was mounted, the hemispherical lens 120 was bonded to the light extraction surface 110a of the semiconductor chip 110 by the following method.
First, the liquid layer 6 was formed by the same method as Example 1, and it was set as the state shown in FIG.4 (b). In this state, the flat surface 121 of the hemispherical lens 120 was pressed onto the liquid layer 6 and left at 200 ° C. for 0.5 hours by the hot plate 5 to evaporate the solvent in the liquid layer 6. Thereby, the bonding layer 131 which is an amorphous fluororesin layer was formed, and the hemispherical lens 120 and the semiconductor chip 110 were bonded by the amorphous fluororesin layer. Bubbles and wrinkles were present in the bonding layer 131.
The adhesive strength between the hemispherical lens 120 of the obtained semiconductor light emitting device and the semiconductor chip 110 was measured by the same method as in Example 1, and found to be 5.1 N / mm ² .

DESCRIPTION OF SYMBOLS 1 Ultraviolet light emitting element 10 Ultraviolet light emitting device 110 Semiconductor chip 110a Semiconductor chip light extraction surface 110b Semiconductor chip side surface 110d Semiconductor chip light extraction surface opposite surface 111 Substrate 112 Semiconductor layer 113 First electrode 114 Second electrode 120 Hemispherical lens 121 Plane (incident surface)
121a Peripheral edge of plane (portion not facing light extraction surface of incident surface)
130 Amorphous fluororesin layer 131 Bonding layer 132 Incident surface covering layer 133 Chip side surface covering layer 134 Rising surface covering layer 135 Connecting layer 136 Lens covering layer 137 External layer 138 Internal layer 2 Package substrate 21 Third electrode 22 Fourth electrode 3 1st connection body 4 2nd connection body 5 Hot plate 6 Liquid layer 61 Resin layer 62 Flowable resin layer

Claims (15)

A semiconductor chip that emits ultraviolet rays;
A UV transmissive lens,
An ultraviolet transmissive bonding layer that bonds the light extraction surface of the semiconductor chip and the incident surface of the lens;
Have
The bonding layer is an amorphous fluororesin layer;
The adhesive strength between the light extraction surface and the incident surface by bonding layer, EIAJ-ED-4703 to a shear strength measured in conformity 6N / mm ² or more 40N / mm ² or less is ultraviolet light emitting element. The incident surface is larger than the light extraction surface;
An incident surface covering layer that covers all of the portion of the incident surface that does not face the light extraction surface;
The ultraviolet light emitting element according to claim 1, wherein the incident surface coating layer is an amorphous fluororesin layer formed continuously with the bonding layer.   3. The ultraviolet light emitting element according to claim 1, wherein a portion of the incident surface that does not oppose the light extraction surface has a rough surface, and the arithmetic average roughness Ra of the rough surface is 100 nm or more and 10 μm or less. A rising surface covering layer covering a rising surface from the incident surface of the lens;
The ultraviolet light emitting element according to any one of claims 1 to 3, wherein the rising surface coating layer is an amorphous fluororesin layer formed continuously with the incident surface coating layer.   The ultraviolet light emitting element according to claim 4, wherein the rising surface covered with the rising surface coating layer has a rough surface, and the arithmetic average roughness Ra of the rough surface is 100 nm or more and 10 μm or less. A chip side surface covering layer covering the side surface of the semiconductor chip;
The ultraviolet light emitting element according to any one of claims 1 to 5, wherein the chip side surface coating layer is an amorphous fluororesin layer formed continuously with the bonding layer and the incident surface coating layer.   The ultraviolet light-emitting element according to claim 6, wherein a side surface of the semiconductor chip covered with the chip side surface coating layer has a rough surface, and an arithmetic average roughness Ra of the rough surface is 100 nm or more and 10 μm or less. A lens coating layer covering the entire surface of the lens other than the incident surface;
The ultraviolet light-emitting element according to claim 1, wherein the lens coating layer is an amorphous fluororesin layer formed continuously with the incident surface coating layer.   The ultraviolet light-emitting element according to claim 1, wherein the lens is a hemispherical lens, and the incident surface is a flat surface.   The ultraviolet light-emitting element according to claim 1, wherein the lens is made of quartz or sapphire.   The light emitting wavelength is 280 nm or less, The ultraviolet light emitting element as described in any one of Claims 1-10.   The ultraviolet light emitting element according to claim 1, wherein the bonding layer has a thickness of 0.1 μm or more and 1.0 mm or less. The ultraviolet light-emitting device according to any one of claims 1 to 12,
A base on which a third electrode and a fourth electrode are formed on a surface facing the surface on which the first electrode and the second electrode of the ultraviolet light emitting element are formed;
A first connection body for electrically connecting the first electrode of the ultraviolet light-emitting element and the third electrode of the base;
An ultraviolet light emitting device comprising: a second connection body that electrically connects the second electrode of the ultraviolet light emitting element and the fourth electrode of the base. All of the surfaces constituting the space formed by the semiconductor chip, the lens, the base, the first connection body, and the second connection body are covered with a continuous amorphous fluororesin layer,
The entire surface constituting the space formed by the semiconductor chip, the base, the first connection body, and the second connection body is covered with a continuous amorphous fluororesin layer. UV light emitting device. A first step of forming a liquid layer of a sealing material including a thermoplastic amorphous fluororesin and a solvent on the entire light extraction surface of a semiconductor chip that emits ultraviolet rays;
A second step in which the liquid layer after the first step is heated to uniformly evaporate the solvent from the surface of the liquid layer, and the liquid layer is formed into a resin layer raised in surface tension;
By heating the resin layer after the second step, the third step to make the resin layer a fluid resin layer in a shape raised by surface tension;
A fourth step of pressing the plane of the lens on the flowable resin layer after the third step while heating the semiconductor chip;
After the fourth step, the fifth step of forming a bonding layer between the plane and the light extraction surface by the amorphous fluororesin by stopping and cooling the semiconductor chip,
A method of bonding a semiconductor chip having a lens and a lens.

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