JP6891450B2 - Manufacturing method of light emitting device - Google Patents

Description

The present disclosure relates to a method for manufacturing a light emitting device.

A method for manufacturing a light emitting device including a step of supplying an uncured resin to the upper surface of a semiconductor light emitting element (hereinafter referred to as a light emitting element) and placing a translucent plate-like member on the uncured resin is known (for example, a patent). Document 1). The uncured resin is formed so as to cover a part of the side surface of the light emitting element by applying its own weight or a load of the translucent plate-shaped member.

Japanese Unexamined Patent Publication No. 2013-197450

There is a need for a method of forming an appropriate amount of uncured resin on the side surface of the light emitting element.

The disclosure includes the following configurations:
A step of preparing a light emitting element, a step of preparing a stamp pin having a recess at the tip having an opening having a width wider than the width of the light emitting element, a bottom surface, and a wall portion, and an inner surface surface of the wall portion. The step of adhering the translucent resin, the opening of the recess of the stamp pin is arranged above the upper surface of the light emitting element, and the inner side surface of the wall portion is arranged outside the side surface of the light emitting element. A method of manufacturing a light emitting device, which comprises a step of moving a part of the light emitting element to a position below the upper surface of the light emitting element and transferring the translucent resin adhering to the inner surface of the wall portion to the side surface of the light emitting element.

As described above, an appropriate amount of uncured resin can be formed on the side surface of the light emitting element.

FIG. 1A is a schematic top view showing a light emitting element according to the embodiment. FIG. 1B is a schematic cross-sectional view showing a light emitting element according to the embodiment. FIG. 1C is a schematic view showing a step of preparing a light emitting element according to an embodiment. FIG. 2A is a schematic side view showing the stamp pin according to the embodiment. FIG. 2B is a schematic perspective view showing a tip portion of the stamp pin shown in FIG. 2A. FIG. 2C is a schematic view of the stamp pin shown in FIG. 2A as viewed from the tip end side. FIG. 2D is a schematic cross-sectional view taken along the line 2D-2D of FIG. 2B. FIG. 3A is a schematic perspective view showing a modified example of the stamp pin. FIG. 3B is a schematic perspective view showing a modified example of the stamp pin. FIG. 4A is a schematic view showing a method of manufacturing a light emitting device according to an embodiment. FIG. 4B is a schematic view showing a method of manufacturing the light emitting device according to the embodiment. FIG. 5A is a schematic view showing a method of manufacturing a light emitting device according to an embodiment. FIG. 5B is a schematic view showing a method of manufacturing the light emitting device according to the embodiment. FIG. 6 is a schematic view showing a method of manufacturing a light emitting device according to an embodiment. FIG. 7A is a schematic view showing a method of manufacturing the light emitting device according to the embodiment. FIG. 7B is a schematic view showing a method of manufacturing the light emitting device according to the embodiment.

A mode for carrying out the present invention will be described below with reference to the drawings. However, the forms shown below exemplify a method for manufacturing a light emitting device for embodying the technical idea of the present invention, and are not limited to the following. Further, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments are not intended to limit the scope of the present invention to that alone unless otherwise specified. The size and positional relationship of the members shown in each drawing may be exaggerated to clarify the explanation. In addition, terms indicating a specific direction or position (for example, "top", "bottom", "right", "left", and other terms including those terms) are used as necessary. The use of these terms is for facilitating the understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the invention. Further, the translucent resin uses the same name both before and after curing.

The method for manufacturing the light emitting device according to the embodiment includes the following steps.
1) Step of preparing the light emitting element 2) Step of preparing the stamp pin 3) Step of adhering the translucent resin to the stamp pin 4) Step of transferring the translucent resin from the stamp pin to the light emitting element I will explain in detail. The steps 1) and 2) are not limited to this order, and the step 1) may be performed after the step 2), or the steps 1) and 2) may be performed in parallel. Good.

1) Step of preparing a light emitting element An example of the light emitting element 10 is shown in FIGS. 1A and 1B. As the light emitting element, for example, a semiconductor light emitting element such as a light emitting diode can be used, and a light emitting element capable of emitting visible light such as blue, green, or red, and further ultraviolet light can be used. The light emitting element 10 is a square having the same width Wc and length Lc. The light emitting element 10 is not limited to a square shape, but may be a rectangular shape. In the case of a rectangle, either the long side or the short side is defined as the width Wc or the length Lc. The light emitting element 10 may be a polygon such as a hexagon or a triangle. The width and length in the case of a hexagon can be the distance between two opposing sides. As for the width and length in the case of a triangle, any one side can be the width, and the distance to the apex facing the one side can be the length.

The light emitting element 10 includes a laminated structure 11 including a light emitting layer and an electrode 12. The laminated structure 11 includes a lower surface (electrode forming surface) 10d on which the electrode 12 is formed, an upper surface (light extraction surface) 10a on the opposite side thereof, and a side surface 10b between the upper surface 10a and the lower surface 10d. .. The upper surface 10a of the laminated structure 11 is also the upper surface of the light emitting element 10. The side surface 10b of the laminated structure 11 is also a side surface of the light emitting element 10. The lower surface of the electrode 12 is the lower surface 10c of the light emitting element 10. The height Hc of the light emitting element 10 is the total height of the height of the laminated structure 11 and the height of the electrodes 12.

The laminated structure includes a semiconductor layer including a light emitting layer. Further, a translucent substrate such as sapphire may be provided. As an example of the semiconductor laminate, a semiconductor layer of a first conductive type semiconductor layer (for example, an n-type semiconductor layer), a light emitting layer (active layer), and a second conductive type semiconductor layer (for example, a p-type semiconductor layer) can be included. .. The semiconductor layer capable of emitting visible light from ultraviolet light or blue light to green light can be formed from a semiconductor material such as a group III-V compound semiconductor. Specifically, _{a nitride-based semiconductor material such as In X} Al _Y Ga _1-XY N (0 ≦ X, 0 ≦ Y, X + Y ≦ 1) can be used. As the semiconductor laminate capable of emitting red light, GaAs, GaAlAs, GaP, InGaAs, InGaAsP and the like can be used.

The light emitting element includes a pair of electrodes, and is arranged on the same surface side (electrode forming surface) on the lower surface of the laminated structure. These pair of electrodes may have a single-layer structure or a laminated structure as long as they are ohmic-connected to the laminated structure so that the current-voltage characteristics are straight or substantially straight. Such electrodes can be formed of any thickness using materials and configurations known in the art. For example, the thickness of the electrode is preferably a dozen μm to 300 μm. Further, as the electrode, a good electric conductor can be used, and for example, a metal such as Cu is suitable. As the electrode shape, various shapes can be selected according to the purpose, application, and the like. The pair of electrodes of the light emitting element may have the same shape or different shapes.

The step of preparing the light emitting element can be prepared through a step of purchasing the light emitting element as described above, a step of forming a part or all of the constituent members, a step of processing, a step of dividing, and the like.

Further, it is preferable that the prepared light emitting element is placed on the adhesive sheet S1 as shown in FIG. 1C, for example. At that time, it is preferable to place the electrode 12 of the light emitting element 10 so as to be in contact with the upper surface of the sheet S1. A plurality of light emitting elements 10 can be arranged on one sheet S1. Such a sheet S1 may be a member used only in the manufacturing process of the light emitting device. That is, it can be used as a member that is not a constituent member of the finally obtained light emitting device. Further, the sheet S1 may be a member that is a constituent member of the finally obtained light emitting device. For example, a flexible substrate or the like in which wiring is provided on a resin sheet such as polyimide may be used. Alternatively, a rigid substrate such as a ceramic substrate or a glass epoxy substrate may be used. When such a substrate to be a constituent member of the finally obtained light emitting device is used, it is preferable that the substrate and the electrode of the light emitting element are connected by a conductive bonding member such as solder.

2) Step of preparing the stamp pin An example of the stamp pin 20 is shown in FIGS. 2A to 2D. The stamp pin 20 is a component used in a die bonder (die bond device), and is used by being attached to an arm that can move in the vertical direction, the horizontal direction, the front-rear direction, and the like. The stamp pin 20 is a member having an appearance as shown in FIG. 2A, and is a long member having a main body portion 21 and a tip portion 22 provided on the tip end side thereof and having a tapered outer diameter. ..

The main body 21 of the stamp pin 20 is cylindrical, and the tip 22 is composed of a truncated cone-shaped portion and a square columnar portion. The main body portion 21 may be a prism, and the tip portion 22 may be a pyramid base portion and a square pillar portion. The tip portion does not have to have a frustum portion.

The tip portion 22 of the stamp pin 20 has a recess 23 composed of an opening 233 that opens to the end face, a bottom surface 231 and a wall portion 232, which are the most advanced ends. The bottom surface 231 of the recess 23 is square, and the wall portion 232 is formed in a frame shape along four sides so as to surround the bottom surface 231. The opening 233 of the recess is also square. The wall portion 232 has an inner side surface 232a constituting the inner side surface of the recess 23 and an outer surface 232c on the opposite side of the inner side surface 232a. Further, a lower surface 232b between the inner surface 232a and the outer surface 232c is provided. Further, as shown in FIG. 3A, the tip portion 22A may be provided with one wall portion on each of the two opposing sides. Alternatively, as shown in FIG. 3B, the tip portion 22B may be provided with four wall portions separated from each other on the four sides.

The height Hr of the wall portion 232 of the stamp pin 20 is equal to or less than the height of the laminated structure 11. The inner side surface 232a of the wall portion 232 may be a surface substantially parallel to the side surface 10b of the light emitting element 10 or a surface inclined with respect to the side surface 10b of the light emitting element 10. Further, the outer surface 232c of the wall portion 232 may be a surface parallel to the inner side surface 232a or a surface inclined with the inner side surface 232a. The width of the lower surface 232b of the wall portion 232 (the shortest distance between the lower end of the inner side surface and the lower end of the outer surface) can be, for example, a width of about 10% to 50% of the width or length of the light emitting element. Further, the inner side surface 232a and the outer side surface 232c may be in contact with each other at the lower ends thereof. That is, it is not necessary to have a lower surface between the inner surface 232a and the outer surface 232c.

The width Wr of the opening 233 of the recess is wider than the width Wc of the light emitting element. For example, the width Wr of the opening 233 can be set to be about 60 to 120 μm larger than the width Wc of the light emitting element. For example, when the width Wc of the light emitting element is about 200 μm, the width Wr of the opening 233 of the recess can be about 300 μm. Further, the length Lr of the opening 233 is longer than the length Lc of the light emitting element. For example, the length Lr of the opening 233 can be a width that is about 60 to 120 μm larger than the length Lc of the light emitting element. For example, when the length Lc of the light emitting element is about 1100 μm, the opening 233 length Lr can be about 1200 μm.
When the inner side surface 232a of the recess is inclined so as to be wider toward the opening side, the width of the opening may be wider than the width Wc of the light emitting element.

When the light emitting element is a polygon other than a quadrangle, the shape of the opening of the recess is preferably a shape corresponding to the number of sides of the light emitting element. For example, in the case of a hexagonal light emitting element, it is preferable that the shape of the opening of the recess is also hexagonal. When the opening of the recess is a polygon other than a quadrangle, the width or length of the recess can also be defined as the width or length of one side of the opening of the recess.

The stamp pin 20 is made of a hard material. For example, ceramics, cemented carbide, hard resin and the like can be mentioned. The size of the stamp pin can be appropriately changed according to the size of the light emitting element and the like.

3) Step of attaching the translucent resin to the stamp pin Next, as shown in FIG. 4A, the translucent resin is attached to the stamp pin 20. A fluid, uncured translucent resin 40a is held in the resin dish 200 provided in the die bonder. The stamp pin 20 is placed on the resin plate 200 and lowered. A part of the tip portion 22 of the stamp pin 20 is lowered to a position where it is immersed in the translucent resin 40a. Specifically, it is lowered to a position where the bottom surface 231 of the recess 23 of the tip portion 22 is immersed. Further, the translucent resin 40a may be thick enough to immerse the bottom surface 231 and the stamp pin may be lowered until it comes into contact with the resin dish 200.

Next, the stamp pin 20 is raised. As shown in FIG. 4B, a part of the translucent resin 40a in the resin dish 200 is attached to the tip portion 22 of the stamp pin 20. Specifically, the translucent resin 40a is attached to the inner side surface 232a of the wall portion 232 of the recess 23. The translucent resin 40a also adheres to the lower surface 232b and the outer surface 232c of the wall portion 232, and further adheres to the bottom surface 231 of the recess 23.

The translucent resin 40a may be attached to at least the inner surface of the wall portion. Therefore, for example, as shown in FIG. 7A, the stamp pin may be lowered so that the bottom surface of the recess of the tip portion 22c does not come into contact with the translucent resin 40a. In such a case, as shown in FIG. 7B, the amount of the translucent resin 40a adhering to the tip portion 22c of the stamp pin can be reduced.

4) Step of transferring the translucent resin from the stamp pin to the light emitting element The stamp pin 20 to which the translucent resin 40a is attached is arranged above the upper surface of the light emitting element 10. Specifically, the stamp pin 20 is arranged so that the center of the recess 23 and the center of the light emitting element 10 substantially coincide with each other. Further, the wall portion 232 is arranged so as to be located outside the side surface 10b of the light emitting element 10. Then, as shown in FIG. 5A, the stamp pin 20 is moved until a part of the wall portion 232 is located below the upper surface 10a of the light emitting element 10. After that, by raising the stamp pin 20, as shown in FIG. 5B, the translucent resin 40a adhering to the inner side surface 232a of the wall portion 232 can be transferred to the side surface 10b of the light emitting element 10. Further, the translucent resin 40a is also transferred to the upper surface of the light emitting element 10. As shown in FIG. 7B, when the translucent resin 40a is not attached to the bottom surface of the recess of the stamp pin, the translucent resin 40a is transferred only to the side surface of the light emitting element 10.

After forming the translucent resin 40 on the upper surface and the side surface of the light emitting element as described above, the light emitting device 100 can be obtained through the following steps. FIG. 6 shows an example of a process of obtaining a light emitting device.

FIG. 6A is a diagram showing a state in which the light emitting element 10 having the translucent resin 40 formed on the upper surface and the side surface is arranged on the sheet S1. Here, a state in which two light emitting elements 10 are arranged side by side is shown. A plurality of three or more light emitting elements 10 can be arranged. Further, it is preferable that the light emitting elements 10 are arranged at equal intervals.

FIG. 6B is a diagram showing a state in which the translucent plate-shaped member 50 is placed on the translucent resin 40. The translucent plate-shaped member 50 is a member placed on the upper surface 10a of the light emitting element 10, and the light from the light emitting element 10 is transmitted to the outside through the translucent plate-shaped member. The translucent resin 40 can function as an adhesive between the light emitting element 10 and the translucent plate-shaped member. By forming the translucent resin on the upper surface of the light emitting element, the adhesive strength between the translucent plate-shaped member and the light emitting element can be improved.

When the translucent resin is not attached to the bottom surface of the recess at the tip of the stamp pin as shown in FIG. 7B, the translucent resin is not transferred to the upper surface of the light emitting element. Therefore, the translucent plate-shaped member is arranged on the upper surface of the light emitting element without using a translucent resin. The amount of the translucent resin can be appropriately selected according to the purpose and application.

The translucent plate-shaped member 50 is referred to as a "plate-shaped" for convenience, but refers to a member including various shapes such as a sheet-shaped, a film-shaped, and a block-shaped member, and uses a translucent resin as an adhesive. Refers to a member attached to the upper surface of a light emitting element. In other words, the translucent plate-shaped member 50 is a member formed in a state where it can be conveyed as an individual.

The translucent resin 40 is uncured before the translucent plate-shaped member 50 is placed. Therefore, when the translucent plate-shaped member 50 is placed, the translucent resin 40 can be pressed and deformed. As a result, as shown in FIG. 6B, the outer surface of the translucent resin 40 becomes an inclined surface.

As the translucent plate-shaped member, a translucent resin, glass, or the like can be used. In particular, a translucent resin is preferable, and a thermosetting resin such as a silicone resin, a silicone-modified resin, an epoxy resin, and a phenol resin, and a thermoplastic resin such as a polycarbonate resin, an acrylic resin, a methylpentene resin, and a polynorbornene resin can be used. it can. In particular, a silicone resin having excellent light resistance and heat resistance is preferable.

The translucent plate-shaped member may include a phosphor as a wavelength conversion member in addition to the translucent material described above. As the phosphor, a phosphor that can be excited by light emission from the light emitting element is used. For example, as a phosphor that can be excited by a blue light emitting element or an ultraviolet light emitting element, an yttrium aluminum garnet fluorescent substance (YAG: Ce) activated by cerium; a lutetium aluminum garnet fluorescent substance activated by cerium is used. (LAG: Ce); nitrogen-containing calcium aluminosilicate-based phosphor activated with europium and / or chromium (CaO-Al ₂ O _3- SiO ₂ ); silicate-based phosphor activated with europium ((Sr, Ba)) ₂ SiO _{4); β-sialon} phosphor, CASN phosphor, nitride-based phosphor such as SCASN phosphor; KSF phosphor _{(K 2 SiF 6: Mn)} ; sulphide phosphor, a quantum dot phosphor And so on. By combining these phosphors with a blue light emitting element or an ultraviolet light emitting element, a light emitting device of various colors (for example, a white light emitting device) can be manufactured.
Further, the translucent plate-shaped member may contain various fillers and the like for the purpose of adjusting the viscosity and the like.

The translucent plate-shaped member can have, for example, a thickness of 50 μm to 500 μm. Further, the size in the top view can be a size substantially equal to or an approximate size to the area of the upper surface of the light emitting element.

Next, the light-shielding member 60 is formed. FIG. 6C is a diagram showing a state in which a light-shielding member 60 is formed around the light emitting element. The light-shielding member 60 is formed so as to fill the space between adjacent light emitting elements. It is preferable to form the light-shielding member 60 also under the light emitting element. Further, it is preferable to form the light-shielding member 60 so as not to cover the upper surface of the translucent plate-shaped member 50. Further, the light-shielding member 60 is preferably formed so as to cover all of the translucent resin 40 formed on the side surface of the light emitting element.

The light-shielding member 60 is preferably a light-reflecting resin member. The light reflectance means that the reflectance with respect to the light from the light emitting element is 70% or more. For example, as the light-shielding member 60, a white resin or the like is preferable. The light that has reached the light-shielding member is reflected and directed toward the light-emitting surface of the light-emitting device, so that the light extraction efficiency of the light-emitting device can be improved.

The light-shielding member 60 is preferably a resin member whose main component is a thermosetting resin such as a silicone resin, a silicone-modified resin, an epoxy resin, or a phenol resin. Then, those in which a light-reflecting substance is dispersed in these translucent resins can be used. As the light-reflecting substance, for example, titanium oxide, silicon oxide, zirconium oxide, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, mullite and the like are suitable. As the light-reflecting substance, granular, fibrous, thin plate pieces and the like can be used, but the fibrous material is particularly preferable because it can be expected to have an effect of reducing the coefficient of thermal expansion of the light-shielding member.

By curing the light-shielding member 60 and then cutting the light-shielding member 60 between the light-emitting elements, it is possible to obtain an individualized light-emitting device 100 as shown in FIG. 6 (d). When cutting, a part or all of the sheet S1 may be cut.

The method for manufacturing a light emitting device according to the present invention can be applied to a method for manufacturing a light emitting device including a step of forming an uncured resin on a light emitting element.

10 ... Light emitting element 11 ... Laminated structure 12 ... Electrode 10a ... Upper surface of light emitting element (light extraction surface)
10b ... Side surface of light emitting element 10c ... Lower surface of light emitting element (lower surface of electrode)
10d ... Lower surface of the laminated structure (electrode forming surface)
Wc ... Width of light emitting element Lc ... Length of light emitting element Hc ... Height of light emitting element 20 ... Stamp pin 21 ... Main body 22, 22A, 22B, 22C ... Tip 23 ... Recess 231 ... Bottom of recess 232 ... Recess Wall part 233 ... Recessed opening 232a ... Inner surface of wall 232b ... Lower surface of wall 232c ... Outer surface of wall Wp ... End face width Lp ... End face length Wr ... Recessed opening width Lr ... Recessed Length of opening Hr ... Height of wall of recess 100 ... Light emitting device 40, 40a ... Translucent resin 50 ... Translucent plate-like member 60 ... Light-shielding member 200 ... Resin plate S1 ... Sheet

Claims (3)

The process of preparing the light emitting element and
A step of preparing a stamp pin having a recess at the tip having an opening having a width wider than the width of the light emitting element, a bottom surface, and a wall portion.
A step of adhering a fluid uncured translucent resin to the inner surface of the wall portion, and
The opening of the recess of the stamp pin is arranged above the upper surface of the light emitting element, and the inner surface of the wall portion is arranged outside the side surface of the light emitting element, and a part of the wall portion is described. A step of moving the light emitting element to a position below the upper surface of the light emitting element and transferring the fluid uncured translucent resin adhering to the inner surface of the wall portion to the side surface of the light emitting element.
A method of manufacturing a light emitting device comprising. The method for manufacturing a light emitting device according to claim 1, wherein the translucent resin is attached to the bottom surface of the recess. The light emitting device according to claim 1 or 2, further comprising a step of arranging a translucent plate-shaped member on the upper surface of the light emitting element and then forming a light-shielding member covering the translucent resin. Production method.

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