JP2015002298A - Light-emitting device, sealing film laminate for manufacturing of the same, and method for manufacturing light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device which is easy to manufacture and where light extraction efficiency is improved, a method of manufacturing the same, and a sealing film laminate used for the manufacturing of the light-emitting device.SOLUTION: In a light-emitting device, an optical film 11 having a fine uneven shape on a surface is disposed on a light extraction direction side of a semiconductor light-emitting element 20a through a sealing adhesive layer 12.

Description

  The present invention relates to a light emitting device such as an LED that is simple to manufacture and excellent in light extraction efficiency, and a sealing film laminate used in the manufacture thereof.

  Conventionally, in the mounting and sealing structure of a semiconductor light emitting device (hereinafter sometimes abbreviated as an LED device), the device is bonded to a base material having high thermal conductivity by Au bumps or resin, and a reflector is provided around the device. A structure that is provided and filled so as to cover the entire element using a sealing material mainly composed of silicone has been widely adopted. This structure reduces the internal reflection caused by the difference in the refractive index at the interface between the outermost surface layer of the LED element and the air by filling the resin, and tries to suppress the decrease in light extraction efficiency caused by the internal reflection. It is configured for the purpose of protecting the LED element against the influence from the external environment.

  This sealing structure is produced by a dispensing method or a molding method in which silicone or epoxy and a composite resin material mainly composed of silicone or epoxy are made liquid or semi-liquid.

  For example, in the dispensing method, there is a problem that the time required for the process to seal each minute package becomes long. The mold method has a problem that a large apparatus is required and the working time of each mold is long. Furthermore, it was necessary to design a dedicated tool for each different package design.

  In these conventional sealing structures, although the refractive index difference between the LED element and the atmosphere is reduced, the refractive index difference between the sealing material and the LED element and the refraction between the sealing material and the atmosphere. The difference in rate is still large, and the problem that the light extraction efficiency is lowered due to the difference in refractive index has not been sufficiently solved.

  In recent years, many high-power compatible LEDs have been commercialized to increase the brightness of LEDs by applying a large voltage in automobile applications. However, in the conventional sealing structure, internal reflection occurs at the interface of each layer due to the difference in refractive index, and some light is converted to heat by repeating re-reflection inside without being emitted outside, As a result, heat is retained and lost. That is, there is a problem that the extraction efficiency of light that can be used as illumination is significantly reduced.

  In order to solve this, various methods have been tried. For example, it has been reported that the refractive index is controlled by a fine uneven structure on the substrate surface. For example, Non-Patent Document 1 (Japan Science and Technology Agency Bulletin 788, published by the Japan Science and Technology Agency (JST) on March 1, 2011, URL: http://www.jst.go.jp/pr/info/ info788 /) and Patent Document 1 (WO2009 / 070809) disclose that the light extraction efficiency is improved by creating a fine uneven shape on the substrate surface that becomes the light extraction surface from the LED element. Yes. Non-Patent Document 1 reports an improvement in light extraction efficiency of about 3.5 times.

  However, in order to form a fine concavo-convex shape on the surface of the substrate, an additional process or apparatus for etching or the like is required, and the manufacturing cost increases, so that the feasibility is poor.

WO2009 / 070809

Japan Science and Technology Agency Bulletin 788, issued on March 1, 2011 Issuing Agency: Japan Science and Technology Agency (JST), URL: http://www.jst.go.jp/pr/info/info788/

  An object of the present invention is to provide a light-emitting device that is simple to produce and has improved light extraction efficiency, a method for producing the light-emitting device, and a sealing film laminate used for the production.

  The present invention relates to the following matters.

  1. A light-emitting device, wherein an optical film having a fine uneven shape on a surface is provided on a light extraction direction side of a semiconductor light-emitting element through a sealing adhesive layer.

  2. 2. The light emitting device according to 1 above, wherein the sealing adhesive layer is provided in direct contact with a light extraction surface of the semiconductor light emitting element.

  3. 3. The above 1 or 2 characterized in that the fine convex-concave convex portion of the optical film has a height of 0.07-1 μm, and the pitch between adjacent convex portions is 0.07-1 μm. Light-emitting device.

  4). 4. The optical film according to any one of the above items 1 to 3, wherein the optical film functions so that a difference in refractive index from the air layer is less than 0.1 on a side having a fine uneven shape. Light emitting device.

  5. Curing of resin including at least one selected from the group consisting of silicone resin, epoxy resin, oxetane resin, acrylate resin, acrylic resin, polycarbonate, cyclic polyolefin, polyimide, polyolefin, phenol resin, and urethane resin. 5. The light-emitting device according to any one of 1 to 4, wherein the light-emitting device is formed of an object.

  6). 6. The light emitting device according to any one of the above 1 to 5, wherein a thickness of the sealing adhesive layer between the optical film and the semiconductor light emitting element is in a range of 100 to 800 [mu] m.

  7). 7. The light emitting device according to any one of 1 to 6, wherein the sealing adhesive layer has a refractive index in a range of 1.4 to 2.5.

  8). 8. The light emitting device according to any one of 1 to 7, wherein the sealing adhesive layer contains a phosphor.

  9. 9. The light-emitting device according to 8 above, wherein the phosphor includes at least one selected from the group consisting of oxide phosphors, nitride phosphors, oxynitride phosphors, and sulfide phosphors.

  10. A sealing film laminate comprising: an optical film having a fine uneven shape on a surface; and an adhesive sheet bonded to a smooth surface of the optical film.

  11. 11. The sealing according to 10 above, wherein the height of the fine irregularities of the optical film is 0.07 to 1 μm, and the pitch between adjacent convexities is 0.07 to 1 μm. Stop film laminate.

  12 The adhesive sheet is obtained from silicone resin, epoxy resin, oxetane resin, acrylate resin, acrylic resin, polycarbonate, cyclic polyolefin, polyimide, polyolefin, phenol resin, urethane resin, and a mixture containing at least one of these resins. 12. The sealing film laminate according to 10 or 11 above, wherein

  13. The thickness of the said adhesive agent sheet is the range of 100-800 micrometers, The sealing film laminated body of any one of said 10-12 characterized by the above-mentioned.

  14 The sealing film laminate according to any one of the above 10 to 13, wherein the adhesive sheet contains a phosphor.

  15. 15. The sealing film laminate according to any one of 10 to 14, wherein a dicing tape is further laminated on the surface of the optical film having a fine uneven shape.

16. The adhesive sheet surface of the sealing film laminate according to any one of 10 to 15 above, a wafer on which a plurality of semiconductor light emitting elements are formed, and a light extraction side surface in contact with the adhesive sheet surface The process of pasting together,
A method of manufacturing a light emitting device, comprising: dicing the wafer bonded to the sealing film laminate together with the optical film and the adhesive sheet into chips.

  17. 17. The method for producing a light emitting device according to 16 above, further comprising a step of heating and curing the adhesive sheet after forming the chip.

  18. A light emitting device comprising: a light emitting device including a semiconductor light emitting element; an optical film having a fine uneven shape on a surface thereof, and an optical refractive index on the light emitting device side of the interface being controlled. .

  19. 19. The light emission according to 18 above, wherein the height of the fine uneven-shaped convex portions of the optical film is 0.07 to 1 μm, and the pitch between the adjacent convex portions is 0.07 to 1 μm. apparatus.

  According to the present invention, it is possible to provide a light emitting device that is simple to manufacture and has improved light extraction efficiency, a method for manufacturing the light emitting device, and a sealing film laminate used for the manufacturing.

It is a schematic diagram showing a typical example of a light emitting device to which a flip chip type semiconductor light emitting element is applied. It is a schematic diagram showing a typical example of a light emitting device to which a face-up type semiconductor light emitting element is applied. It is a figure which shows typically the cross section of the optical film which has a fine unevenness | corrugation. It is sectional drawing which shows one example of the sealing film laminated body containing an optical film and an adhesive agent sheet. It is a top view of the sealing film laminated body of FIG. It is a figure which shows the roll form of the sealing film laminated body of FIG. It is sectional drawing which shows one example of the sealing film laminated body containing an optical film and an adhesive agent sheet. It is a figure which shows the roll winding form of the sealing film laminated body of FIG. It is a figure which shows one example (embodiment A-1) of the manufacturing method of a light-emitting device. FIG. 10 is a diagram illustrating an example (Embodiment A-1) of a method for manufacturing a light-emitting device, following FIG. 9. It is a figure which shows one example (embodiment A-2) of the manufacturing method of a light-emitting device. It is a figure which shows one example (embodiment B-1) of the manufacturing method of a light-emitting device. FIG. 13 is a diagram illustrating an example (Embodiment B-1) of a method for manufacturing a light-emitting device, following FIG. 12. It is a figure which shows one example (embodiment B-2) of the manufacturing method of a light-emitting device.

<< Structure of Light Emitting Device >>
As described above, the light-emitting device of the present invention includes (i) a semiconductor light-emitting element, (ii) an optical film having a fine uneven shape on the surface, and (iii) a light extraction direction of the semiconductor light-emitting element. A sealing adhesive layer for adhering the film to the semiconductor light emitting device;

  In the present application, the “semiconductor light emitting device” means a structure of a minimum unit capable of emitting light alone by inputting current, and is formed on a growth substrate (which may be finally removed). A structure including a semiconductor layer structure including a semiconductor layer (including a photoactive layer, a p-type cladding layer, an n-type cladding layer, etc.) and an electrode layer formed in contact with the semiconductor layer, including a sealing resin and a phosphor First, it means both before and after connecting bumps and bonding wires. Further, in the present application, the “semiconductor die” means one that is separated as a unit of one light emitting element after the semiconductor multilayer structure is formed.

  The semiconductor light emitting element is preferably an LED (light emitting diode), and the wavelength of light emitted from the element is not particularly limited.

  Schematic diagrams of typical examples of the light emitting device of the present invention are shown in FIGS. FIG. 1 shows an example in which the present invention is applied to a semiconductor light emitting device (LED) called a flip chip type. In the flip chip type, the growth direction of the semiconductor layer (photoactive layer, p-type cladding layer, n-type cladding layer, etc.) included in the semiconductor light emitting element 20a is downward in this drawing, and the n electrode and p electrode are downward. become. The semiconductor light emitting element is connected to a wiring 22 formed on the surface of the support 23 by a bump 21 or the like for current injection. In this semiconductor light emitting device, the light extraction direction is upward in the drawing, and the upper layer on the light extraction side in the semiconductor light emitting device 20a is a substrate (sapphire substrate, GaN substrate, etc.) used for the growth of the semiconductor layer. Alternatively, the growth substrate may be removed.

  In this embodiment, an optical film 11 (hereinafter sometimes simply referred to as an optical film) having a fine irregular shape on the surface is provided via a sealing adhesive layer 12 in the light extraction direction of the semiconductor light emitting element 20a. .

  FIG. 2 shows an example in which the present invention is applied to a semiconductor light emitting device (LED) called a face-up type. In the face-up type, in general, the growth direction of a semiconductor layer (photoactive layer, p-type cladding layer, n-type cladding layer, etc.) is upward in the drawing, and the n electrode and the p electrode are located above the semiconductor light emitting element 20b. It is provided upward and connected to the wiring 22 formed on the surface of the support 23 by wire bonding 24. Also in this semiconductor light emitting device, the light extraction direction is the upward direction of the drawing.

  Also in this embodiment, the optical film 11 having a fine uneven shape on the surface is provided via the sealing adhesive layer 12 in the light extraction direction of the semiconductor light emitting element 20b.

  In the present invention, as shown in FIGS. 1 and 2, an optical film having fine irregularities on the surface is attached by a sealing adhesive layer 12 in the light extraction direction of the semiconductor light emitting devices (20 a, 20 b). Therefore, the light extraction efficiency is improved. This is because the effective refractive index at the interface with the external air layer is modulated stepwise due to the fine unevenness, and internal reflection is reduced.

  The sealing adhesive layer only needs to have a function of adhering at least the optical film to the semiconductor light-emitting element, but also has a function of protecting the semiconductor light-emitting element from the external environment. Further, as will be described later, a wavelength conversion function can be provided by including a phosphor in the sealing adhesive layer.

  In this invention, an optical film can be manufactured separately from manufacture of a semiconductor light-emitting device, and a light-emitting device can be manufactured by adhere | attaching it. For this reason, the manufacturing process is greatly simplified, and the light emitting device can be manufactured at low cost. An example of the manufacturing process will be described later.

  In a different aspect of the light emitting device of the present invention, an optical film having fine irregularities on the surface is provided at the interface with the air of the light emitting device including a semiconductor light emitting element, and the optical refractive index on the light emitting device side of the interface is controlled. It is characterized by being. When the optical film is present at the interface with the external air layer, the refractive index is appropriately controlled, and preferably the refractive index difference with air is less than 0.1. The height of the fine irregularities of the optical film is 0.07 to 1 μm, the pitch between adjacent convexes is 0.07 to 1 μm, and the height and pitch of the convexes are in these ranges. By adjusting in the range, the refractive index preferable for the light emitting device can be obtained.

<< Materials constituting light-emitting device >>
First, main members constituting the light emitting device will be described.

<Optical film with fine irregularities>
The optical film used in the present invention is formed of a substantially transparent material in the wavelength region to be used, and has irregularities on the light extraction side as schematically shown in FIG. 3 (cross-sectional view). Concavities and convexities are formed periodically, and the pitch between adjacent convex portions 111 and convex portions 111 is 0.07 μm to 1 μm, preferably 0.3 to 0.7 μm.

  The convex portion is not particularly limited as long as it has a shape that gradually decreases as it proceeds in the light extraction direction (upward in FIG. 3), that is, a shape in which the cross-sectional area of the convex portion decreases toward the upper side. For example, as shown in FIG. 3, a semi-elliptical rotator shape (preferably the major axis is in the vertical direction), a bell shape, a cone shape, a hexagonal pyramid shape, and the like can be given.

  The height t1 of the convex portion is preferably 0.07 μm to 1 μm, and the aspect ratio (height / pitch) is preferably 0.5 or more, more preferably 1 or more, and usually 5 or less.

  Examples of the material constituting the optical film include silicone resin, polyethylene terephthalate (PET), polyethersulfone (PES), thermosetting resin elastomers such as silicone rubber and fluoro rubber, PMMA, polycarbonate, cyclic polyolefin, polyimide, polyolefin, Examples thereof include a cycloolefin polymer, a phenol resin, and a resin mainly containing at least one selected from these. Of these, silicone resin, polycarbonate, PMMA, cycloolefin polymer and the like are preferable, and silicone resin is particularly preferable.

  Moreover, the lamination | stacking of 2 or more types of resin may be sufficient. For example, the surface unevenness or the surface unevenness and the thin layer that supports the surface unevenness may be formed of a material different from the base material film that constitutes most of the optical film. Most of the optical film is preferably formed of a resin having excellent transparency and durability, such as silicone resin, polycarbonate, PMMA, cycloolefin polymer, and the like, and particularly preferably silicone resin. The surface unevenness or the surface unevenness and the thin layer that supports the surface unevenness are preferably a cured product of a resin composition containing a (meth) acrylate resin (a resin containing a (meth) acryloyl group).

  The optical film may contain a fine inorganic filler in addition to the resin, whereby the refractive index of the optical film can be adjusted.

  The refractive index of the material constituting the optical film is preferably between 1.3 and 1.7. A necessary refractive index can be achieved by selecting a resin as a base material and adjusting the kind and amount of the inorganic filler added as necessary.

  In this optical film, the difference in effective refractive index from the air layer at the interface 13 with the air layer shown in FIG. 3 is preferably less than 0.1. As shown in FIG. 3, when the thickness up to the tip of the convex portion 111 of the optical film is t, the effective refractive index difference with the air layer is 0.1, and no irregularities are formed on the surface. This means that the difference in refractive index at the interface between the film having a smooth thickness t and the air is equivalent to 0.1. That is, it means that light emitted from the optical film is hardly internally reflected on the surface provided with fine irregularities. Although the thickness t of an optical film is not specifically limited, For example, it can select suitably in the range of 10 micrometers-5 mm, more typically 20 micrometers-1 mm.

  Next, an example of the manufacturing method of an optical film is demonstrated easily. First, a cylindrical mold having a fine concave mold is manufactured and placed between a long film unwinding chamber and a winding chamber. Before the base film coming out of the unwind chamber passes through the mold, a liquid UV curable resin is injected into the mold, and the liquid resin in the mold is irradiated with UV when the film passes through the mold. An optical film having irregularities on the surface can be formed by winding while adhering to the film while curing. Since this method can be manufactured by a roll-to-roll method, it can be mass-produced at a low cost.

  The concave shape of the mold is set so that fine irregularities on the surface of the optical film have a predetermined shape that matches the optical characteristics of the semiconductor light emitting element and the sealing adhesive layer, but the height is 0.07 to 1 μm. In such a range, it is preferable that the convex part on the surface of the optical film has the above-mentioned shape in the range of 0.07 to 1 μm in pitch.

  Similarly, the optical film can also be manufactured by utilizing a technique such as nanoimprint in which a fine pattern is transferred onto a resin surface or the like using a printing technique by a roll-to-roll method.

  The base film can be selected from the aforementioned “materials constituting the optical film”. The liquid UV curable resin may be a UV curable resin, and examples thereof include a resin composition containing a (meth) acrylate resin (a resin containing a (meth) acryloyl group).

<Sealing adhesive layer>
In the present invention, the sealing adhesive layer adheres the optical film to the semiconductor light emitting element, and the refractive index is a value between the refractive index of the material on the light extraction side surface of the semiconductor light emitting element and the refractive index of air. Preferably, it has a value between the refractive index of the material on the light extraction side surface of the semiconductor light emitting element and the refractive index of the material on the adhesive surface side of the optical film.

  Specifically, the refractive index of the sealing adhesive layer is preferably in the range of 1.4 to 2.5, and the refractive index of the material on the light extraction side surface of the semiconductor light emitting element and the material on the adhesive surface side of the optical film It is preferable to set appropriately in consideration.

  The resin constituting the sealing adhesive layer may be a thermosetting resin, a thermoplastic resin or the like as long as it has predetermined physical properties (hardness, heat resistance, durability, transparency, refractive index, etc.) in the final product. Any of composite resins may be used. When a curable resin is used in the manufacturing process as the resin constituting the sealing adhesive layer, the sealing adhesive layer in the final product means a resin layer that has been finally cured.

  For example, at least selected from the group consisting of silicone resin, epoxy resin, oxetane resin, modified silicone resin, modified epoxy resin, modified oxetane resin, acrylate resin, acrylic resin, polycarbonate, cyclic polyolefin, polyimide, polyolefin, phenol resin, urethane resin Those containing one kind are preferred. In the final product, the sealing adhesive layer is in a state where these resins are finally cured. Among these, silicone resins, epoxy resins, oxetane resins, modified silicone resins, modified epoxy resins, modified oxetane resins, and mixtures containing the same are more preferable. A silicone resin is particularly preferable from the viewpoint of transparency and durability. The sealing adhesive forming the sealing adhesive layer will be described in the item of the manufacturing method described later.

  The thickness of the sealing adhesive layer, that is, the distance between the light extraction side surface of the semiconductor light emitting element and the optical film can be changed according to the purpose, but can be set in the range of 100 to 800 μm, for example.

  The sealing adhesive layer may cover the side surface of the semiconductor light emitting element (semiconductor die). For example, in the face-up type, the semiconductor light emitting element may be covered including wire bonding.

  In one preferred embodiment of the present invention, the sealing adhesive layer can include a phosphor. The phosphor that can be used is not particularly limited, and phosphors used in known semiconductor light emitting devices can be used.

For example, an oxide phosphor such as YAG (Y ₃ Al ₅ O ₁₂ : Ce), TAG (Tb ₃ Al ₅ O ₁₂ : Ce), and silicate (Ca ₃ MgSi ₄ O ₁₆ Cl ₂ : Eu) is referred to as 258Nitride. Nitride phosphors such as Ca ₂ Si ₅ N ₈ , oxynitriding typified by SiAlON of α-type (M _x (SiAl) ₁₂ (ON) ₁₆ ) and β-type ((SiAl) ₆ (ON) ₃ : Eu) Type phosphors and sulfide phosphors. These may be used alone or in combination of two or more. In addition, phosphors not exemplified here can be used alone or mixed with the phosphors exemplified above.

  A light-emitting device that emits white light or a desired color can be obtained by combining the emission wavelength of the semiconductor light-emitting element and the phosphor.

  When the phosphor is contained in the sealing adhesive layer, the content of the phosphor is usually 0.1 to 120 parts by weight, preferably 1 to 100 parts by weight with respect to 100 parts by weight of the sealing adhesive layer (at the time of curing). Part.

  Further, the sealing adhesive layer may have a multilayer structure, for example, a layer containing a phosphor and a layer containing no phosphor or a smaller amount. Moreover, the fluorescent substance from which luminescent color differs can also be contained in a respectively different layer.

<< Method for Manufacturing Light-Emitting Device and Materials Used for Manufacturing >>
Next, an embodiment of a method for manufacturing a light emitting device will be described. First, the sealing film laminate suitably used in the manufacturing method described here will be described, and then the manufacturing process will be described.

<Sealing film laminate>
The sealing film laminate of the present invention has a structure in which the optical film described above and an adhesive sheet for forming the sealing adhesive layer described above are stacked. The adhesive sheet is subjected to a curing treatment as necessary to become the above-described sealing adhesive layer. Here, the term “adhesive sheet” includes not only a self-supporting form but also a form that is not self-supporting and exists in the form of a layer attached on a substrate. The term “sheet” is used for those that are present before being cured.

  One example of the sealing film laminate of the present invention is shown in FIG. 4 (transverse sectional view). The sealing film laminate of the present invention has a structure in which an adhesive sheet 32 is laminated on a smooth surface (a surface on which fine irregularities are not formed) of the optical film 11. It is preferable that a sealing film laminated body is hold | maintained on the peeling base material sheet 33 like PET. Furthermore, the optical film 11 and the adhesive sheet 32 may be covered with the dicing tape 34. When the sealing film laminate of this form is seen from a plane so that it can be immediately bonded to a wafer or a substrate, as shown in FIG. 5, the optical film 11 and the adhesive sheet 32 have, for example, a circular shape. The dicing tape 34 is formed in a shape larger than the outer shape of the optical film 11 and the adhesive sheet 32, that is, a larger circle in this example.

  The cut shapes of the optical film 11, the adhesive sheet 32, and the dicing tape 34 can be appropriately adjusted to the shape of the wafer to which the sealing film laminate is bonded. In addition to the circular shape shown in the figure, any shape such as an oval shape, a square shape, a rectangular shape may be used, and can be set as appropriate according to the purpose of use.

  As a form (product form) at the time of manufacture of the sealing film laminate of this form, one unit of the laminated structure of the optical film 11 / adhesive sheet 32 / dicing tape 34 is on one release substrate sheet 33. Even in the formed form, a plurality of units of the laminated structure of the optical film 11 / adhesive sheet 32 / dicing tape 34 may be formed on one release substrate sheet 33. For example, as shown in FIG. 6, the laminated structure of the optical film 11 / adhesive sheet 32 / dicing tape 34 is formed on the long release substrate sheet 33 at intervals, and is in a state of roll winding. Can also be provided.

  In FIG. 7, sectional drawing of the different form of the sealing film laminated body of this invention is shown. In this example, there is no dicing tape, and the adhesive sheet 32 is laminated on the smooth surface of the optical film 11 and is held on the release substrate sheet 33. The sealing film laminated body of this form can also be provided as a cut sheet or in a rolled state as shown in FIG.

  In the sealing film laminate, the adhesive sheet 32 is in a semi-cured state (B-stage state, that is, solid or semi-solid). By curing under the final curing conditions, a final cured product, that is, a sealing adhesive layer in the light emitting device is obtained.

  The material constituting the adhesive sheet is silicone resin, epoxy resin, oxetane resin, modified silicone resin, modified epoxy resin, modified oxetane resin, acrylate resin, acrylic resin, polycarbonate, cyclic polyolefin, polyimide, polyolefin, phenol resin, urethane Examples thereof include a resin and a mixture containing at least one of these resins.

  Among these, a resin that can be finally cured by heating is preferable, and a silicone resin, an epoxy resin, an oxetane resin, a modified silicone resin, a modified epoxy resin, a modified oxetane resin, and a copolymer or a mixture containing the same are preferable. A silicone resin is particularly preferable from the viewpoint of transparency and durability.

  Examples of the silicone resin include polysiloxanes containing organopolysiloxanes having hydrosilyl groups, curing catalysts such as platinum catalysts, and addition curable silicone resin compositions containing a curing retarder as necessary. After applying a liquid resin to a suitable release substrate, proceed with partial curing, or after dissolving / dispersing a polysiloxane having a predetermined molecular weight in a solvent together with other additives and applying it to a suitable substrate By removing the solvent by drying, a semi-cured (solid, semi-solid) sheet can be formed. A sealing film laminated body is obtained by bonding the obtained sheet | seat with an optical film.

  Even when epoxy resin, oxetane resin, acrylate resin, etc. are used, a composition containing an appropriate curing agent is prepared together with the resin, and a semi-cured (solid, semi-solid) sheet is formed in the same manner. Can do. By sticking the obtained sheet | seat on an optical film, a sealing film laminated body is obtained.

  Since the volume of the adhesive sheet does not change greatly even after final curing, it can be set to the same level as that of the sealing adhesive layer in the light emitting device, for example, in the range of 100 to 800 μm. The temperature for heat curing is, for example, 80 ° C to 300 ° C.

  When the phosphor is contained in the sealing adhesive layer of the completed light-emitting device, the phosphor may be contained in the production of the adhesive sheet. For example, in the stage where the resin is liquid and / or in the solution It is preferable to mix a phosphor.

  Further, when the sealing adhesive layer has a multilayer structure, the adhesive sheet may be formed as a multilayer structure.

<Method for manufacturing light emitting device>
The manufacturing method of the light emitting device includes the adhesive sheet surface of the sealing film laminate, the wafer on which the plurality of semiconductor light emitting elements are formed, and the light extraction side surface of the semiconductor light emitting element in contact with the adhesive sheet surface. Thus, there are a step of bonding, and a step of dicing the wafer bonded to the sealing film laminate together with the optical film and the adhesive sheet to form a chip.

  The adhesive sheet can be finally cured by heating after chip formation. A typical embodiment of the manufacturing method will now be described.

<Embodiment A-1 of Manufacturing Method>
The manufacturing method of the light-emitting device using the sealing film laminated body with a dicing tape is demonstrated.

  As shown in FIG. 9A, a protective tape 41 is attached to the surface (element formation surface) of a wafer 42 on which a semiconductor light emitting element structure with solder bumps is formed.

  4 is prepared (a laminated structure of the dicing tape 34, the optical film 11, the adhesive sheet 32, and the peeling base sheet 33), and the peeling base sheet 33 is peeled off to expose the adhesive sheet. 32 is affixed to the wafer 42 to obtain the structure shown in FIG. Next, as shown in FIG. 9C, the protective tape 41 is peeled off.

  As shown in FIG. 10 (d), the wafer is diced by a laser or a dicing blade into individual pieces. As shown in FIG. 10E, after the dicing tape is appropriately stretched, the separated semiconductor light emitting element 20a is picked up. At this time, the sealing film laminate (the optical film 11 and the adhesive sheet 32) is also singulated together with the semiconductor light emitting element 20a.

  Next, as shown in FIG. 10 (f), the semiconductor die (semiconductor light emitting element) with the sealing film laminate is mounted on the mounting substrate 23 by the flip chip mounting. After that, the adhesive sheet 32 is finally cured by heating at a predetermined temperature for a predetermined time, thereby forming the sealing adhesive layer 12 to complete the light emitting device.

<Embodiment A-2 of Manufacturing Method>
The manufacturing method of the light-emitting device using the sealing film laminated body without a dicing tape is demonstrated.

  As shown in FIG. 11A, similarly to Embodiment A-1, a protective tape 41 is attached to the surface (element formation surface) of a wafer 42 on which a semiconductor light emitting element structure with solder bumps is formed.

  The sealing film laminate (laminated structure of the optical film 11, the adhesive sheet 32, and the release base sheet 33) shown in FIG. 7 is prepared, the release base sheet 33 is peeled off, and the exposed adhesive sheet 32 is removed from the wafer 42. To obtain the structure shown in FIG.

  The optical film 11 and the adhesive sheet 32 are cut with a size equal to or larger than the wafer 42 (for example, a size about 5 mm larger). Thereafter, the dicing tape 34 is attached, and the dicing tape is cut into a size larger than the wafer to obtain the structure shown in FIG. This structure is substantially the same as the structure of FIG. 9B described in the embodiment A-1. Therefore, the subsequent steps can complete the light-emitting device according to the steps described in Embodiment A-1.

<Embodiment B-1 of Manufacturing Method>
The example of the manufacturing method of the light-emitting device using the sealing film laminated body with a dicing tape is demonstrated. In this manufacturing method, a semiconductor light-emitting element mounted on a support is used.

  As shown in FIG. 12A, an intermediate array structure in which a plurality of (many) semiconductor light emitting elements are mounted on a support 23 is prepared. The support is different from the substrate used for semiconductor growth, and a ceramic substrate such as AlN can be used. The semiconductor light emitting device is not particularly limited, such as a flip chip type and a face up type. That is, a large number of semiconductor light emitting elements (such as flip chip type 20a or face up type 20b) are mounted on the support 23, and are connected to predetermined wirings or electrodes on the support by bumps or wire bonding. Yes.

  4 is prepared (a laminated structure of the dicing tape 34, the optical film 11, the adhesive sheet 32, and the peeling base sheet 33), and the peeling base sheet 33 is peeled off to expose the adhesive sheet. 32 is affixed on the semiconductor light emitting element mounting surface of the support body 23, and the structure shown in FIG.12 (b) is obtained. If there is a protective tape on the back side of the support 23, it is also removed.

  As shown in FIG. 12 (c), the wafer is diced by a laser or a dicing blade into individual pieces. As shown in FIG. 13D, after the dicing tape is appropriately stretched, the support 23 that has been separated into individual pieces is picked up. At this time, the sealing film laminate (the optical film 11 and the adhesive sheet 32) is also separated into pieces together with the support 23.

  As shown in FIG. 13 (e), the singulated support body 23 with the sealing film laminate with the semiconductor light emitting element mounted thereon is mounted on a mounting substrate as necessary. Thereafter, the adhesive sheet 32 is finally cured by heating at a predetermined temperature for a predetermined time, and becomes the sealing adhesive layer 12, thereby completing the light emitting device.

  Although FIG. 13E shows a flip chip type, the present invention can also be applied to a face-up type or other forms of semiconductor light emitting elements.

<Embodiment B-2 of Manufacturing Method>
The manufacturing method of the light-emitting device using the sealing film laminated body without a dicing tape is demonstrated.

  As shown in FIG. 14A, an intermediate array structure in which a plurality of (many) semiconductor light emitting elements are mounted on a support 23 is prepared in the same manner as in Embodiment B-1. A large number of semiconductor light emitting elements (such as a flip chip type 20a or a face-up type 20b) are mounted on the support 23, and are connected to predetermined wirings or electrodes on the support by bumps or wire bonding.

  The sealing film laminated body (laminated structure of the optical film 11, the adhesive sheet 32, and the peeling base material sheet 33) shown in FIG. 7 is prepared, the peeling base material sheet 33 is peeled off, and the exposed adhesive sheet 32 is supported. The structure shown in FIG. 14B is obtained by pasting on the semiconductor light emitting element mounting surface 23.

  The optical film 11 and the adhesive sheet 32 are cut with the same size as or larger than the support 23 (for example, about 5 mm larger). Thereafter, the dicing tape 34 is attached, and the dicing tape is cut into a size larger than the wafer to obtain the structure shown in FIG. If there is a protective tape on the back side of the support 23, it is also removed. This structure is substantially the same as the structure of FIG. 12B described in the embodiment B-1. Therefore, the subsequent steps can complete the light-emitting device according to the steps described in Embodiment B-1. In this example, a flip chip type is shown, but the present invention can also be applied to a face-up type or other forms of semiconductor light emitting elements.

  In the description of the above embodiment, when a phosphor is contained in the sealing adhesive layer, a sealing film laminate containing the phosphor in the adhesive sheet may be used. Moreover, after apply | coating fluorescent substance to the surface of a semiconductor light-emitting device, you may bond together with the adhesive agent sheet of a sealing film laminated body.

  The light emitting device of the present invention can be applied to various uses. For example, in consumer and industrial lighting, automobile headlights, and rear lights at the rear of the vehicle body, the light-emitting device of the present invention can be further re-mounted to provide a lens. Alternatively, the present invention can be applied to a use in place of a lens.

<Example of optical film production>
A silicone resin is used as the base film, and a mold as described in the above section <Optical film with fine irregularities> is used to form a fine irregular shape with a UV curable resin. An optical film was obtained. The shape of the irregularities is a bell-shaped cone having a height of 0.5 μm and a pitch (diameter) of 0.3 μm. The obtained optical film has a thickness of 50 μm and a refractive index of 1.4 (material refractive index).

<Manufacture example 1 of a sealing film laminated body>
Manufacturing method of sealing film laminate for LED chip with dicing tape YAG phosphor was added to an uncured silicone resin solution and stirred to prepare a silicone resin solution containing the phosphor.

  Next, the silicone resin solution obtained above was coated on a 38 μm thick polyester film (PET film), dried at 80 ° C. for 5 minutes, and semi-cured to obtain an adhesive sheet having a thickness of 500 μm.

  Next, the optical film which has the fine unevenness | corrugation manufactured by said "manufacturing example of an optical film" was affixed on the surface (opposite side to PET film) of an adhesive sheet at 80 degreeC.

  Using a die cut roll knife, the optical film and the adhesive sheet were cut into a circular shape so that the PET film was cut by 5 to 20 μm (half cut). The size of the circle may be the same as the size of the substrate to be attached, or may be about 20 to 30 mm larger. After removing the circular outer optical film and the adhesive sheet portion, a pressure-sensitive dicing tape having a thickness of 85 μm was attached. Using a die-cut roll knife, the dicing tape was cut into a circular shape by cutting 5 to 20 μm into the PET film (half cut). The size of the circle may be the same as the size of the wafer ring to be attached or about 10 to 20 mm smaller. The cut circular outer dicing tape was removed to complete the sealing film laminate. In addition, this sealing film laminated body respond | corresponds to the form shown in FIG.

<Manufacture example 2 of a sealing film laminated body>
Manufacturing method of sealing film laminate for LED chip without dicing tape A TAG phosphor was added to an uncured silicone resin solution and stirred to prepare a silicone resin solution containing the phosphor.

  Next, the silicone resin solution obtained above was coated on a 38 μm thick polyester film (PET film), dried at 80 ° C. for 5 minutes, and semi-cured to obtain an adhesive sheet having a thickness of 500 μm.

  Next, on the surface of the adhesive sheet (on the side opposite to the PET film), the optical film having fine irregularities manufactured in the above-mentioned “optical film manufacturing example” is attached at 80 ° C., and the sealing film laminate Was completed. In addition, this sealing film laminated body respond | corresponds to the form shown in FIG.

<Production Example 1 of Light-Emitting Device>
Example of Production Method Embodiment A-1 An LED wafer was prepared in which a large number of LED elements with solder bumps were formed on a 4-inch circular wafer (150 μm thick). A protective tape (a back grind tape having a thickness of 300 μm) was attached to the surface of the element formation surface of this LED wafer at room temperature to eliminate the irregularities on the surface of the protective tape.

  The film produced in Production Example 1 of the sealing film laminate was peeled off from the PET film on the backside of the wafer and then attached at 80 ° C. After peeling off the protective tape on the surface, the LED chip was separated into pieces by a blade dicing method. After separating into chips, the chip was peeled off from the dicing tape and mounted on a mounting board with a lip chip. The mounted device was placed in an oven at 150 ° C. for 2 hours to cure the silicone adhesive layer (adhesive sheet), thereby completing the light emitting device.

<Production Example 2 of Light Emitting Device>
Example of Production Method Embodiment A-2 An LED wafer was prepared in which a large number of LED elements with solder bumps were formed on a 4-inch circular wafer (150 μm thick). A protective tape (a back grind tape having a thickness of 300 μm) was attached to the surface of the element formation surface of this LED wafer at room temperature to eliminate the irregularities on the surface of the protective tape.

  The film produced in Production Example 2 of the sealing film laminate was peeled off from the PET film on the back surface of the wafer and then attached at 80 ° C. The optical film and the adhesive sheet portion were cut to a size about 5 mm larger than the wafer. Thereafter, a pressure-sensitive dicing tape having a thickness of 85 μm was attached to the optical film at room temperature.

  The dicing tape was cut into the size of a wafer ring, and then the surface protective tape was peeled off, and then the LED chip was separated into pieces by a blade dicing method. After separation into individual pieces, the chip was peeled off from the dicing tape and mounted on a mounting board with a lip chip. The mounted device was placed in an oven at 150 ° C. for 2 hours to cure the silicone adhesive layer, thereby completing a light emitting device.

<Production Example 3 of Light-Emitting Device>
Example of Production Method Embodiment B-1 A wafer in which a large number of LED chips (150 μm thick, 0.2 × 0.5 mm size) were flip-chip bonded onto an 8-inch circular 150 μm thick ceramic (AlN) substrate was prepared. A protective tape was attached to the back surface of the wafer at room temperature.

  The film produced in Production Example 1 of the sealing film laminate was peeled off from the PET film and pasted at 80 ° C. on the element forming surface of the substrate. After peeling off the protective tape, the LED chip was separated into pieces by a blade dicing method. After separating into pieces, the LED elements were peeled off from the dicing tape and mounted on a mounting board. The mounted device was placed in an oven at 150 ° C. for 2 hours to cure the silicone adhesive layer (adhesive sheet), thereby completing the light emitting device.

<Example 4 of light-emitting device production>
Example of Production Method Embodiment B-2 A wafer was prepared by flip-chip bonding a number of LED chips (150 μm thickness, 0.2 × 0.5 mm size) on an 8-inch circular 150 μm thick ceramic (AlN) substrate. A protective tape was attached to the back surface of the wafer at room temperature.

  The film produced in Production Example 2 of the sealing film laminate was peeled off from the PET film and pasted at 80 ° C. on the element forming surface of the substrate. The optical film and the adhesive sheet portion were cut to a size about 5 mm larger than the wafer. Thereafter, a pressure-sensitive dicing tape having a thickness of 85 μm was attached to the optical film at room temperature.

  The dicing tape was cut into the size of a wafer ring, and then the protective tape was peeled off, and then the LED chip was separated into pieces by a blade dicing method. After separating into pieces, the LED elements were peeled off from the dicing tape and mounted on a mounting board. The mounted device was placed in an oven at 150 ° C. for 2 hours to cure the silicone adhesive layer (adhesive sheet), thereby completing the light emitting device.

<Example 5 of light-emitting device production>
Example of Manufacturing Method Embodiment B-1 (Face-up LED)
A number of LED chips (150 μm thick, 0.2 × 0.5 mm size) were die-bonded on an 8-inch circular 150 μm thick ceramic (AlN) substrate using a die attach paste adhesive. After the paste adhesive was cured, it was wire-bonded with a 25 μm diameter gold wire and electrically connected to the wiring (electrode) on the ceramic substrate. The wafer thus manufactured was used, and thereafter, a light emitting device (face-up type LED) was completed in the same manner as in “Light Emitting Device Production Example 3”.

<Production Example 6 of Light-Emitting Device>
Example of Manufacturing Method Embodiment B-2 (Face-up LED)
A number of LED chips (150 μm thick, 0.2 × 0.5 mm size) were die-bonded on an 8-inch circular 150 μm thick ceramic (AlN) substrate using a die attach paste adhesive. After the paste adhesive was cured, it was wire-bonded with a 25 μm diameter gold wire and electrically connected to the wiring (electrode) on the ceramic substrate. The wafer thus manufactured was used, and thereafter, a light emitting device (face-up type LED) was completed in the same manner as in “Light Emitting Device Production Example 4”.

  As described above, the LED devices manufactured in the light emitting device manufacturing examples 1 to 6 have a difference in refractive index of about 0.4 to 0.5 between the silicone resin serving as the sealing material and the external air layer in the conventional structure. On the other hand, since the fine unevenness gradually modulates the refractive index at the interface with the external air layer, it was possible to control the refractive index difference as small as about 0.01. Compared to an LED manufactured without using an optical film, it was possible to confirm the effect of obtaining a light output of at least 1.2 times or more.

  The present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the spirit of the present invention.

  The light-emitting device of the present invention can be applied to various uses such as consumer and industrial lighting and indicators, automobile headlights, and rear lights at the rear of a vehicle body.

DESCRIPTION OF SYMBOLS 11 Optical film 12 Sealing adhesive layer 20a Semiconductor light emitting element Flip chip type | mold 20b Semiconductor light emitting element Face up type | mold 21 Bump 22 Wiring 23 Support body 24 Bonding wire 32 Adhesive sheet 33 Peeling base sheet 34 Dicing tape 41 Protection tape 42 Wafer 111 Convex

Claims (19)

  A light-emitting device, wherein an optical film having a fine uneven shape on a surface is provided on a light extraction direction side of a semiconductor light-emitting element through a sealing adhesive layer.   The light emitting device according to claim 1, wherein the sealing adhesive layer is provided in direct contact with a light extraction surface of the semiconductor light emitting element.   The height of the fine uneven | corrugated shaped convex part of the said optical film is 0.07-1 micrometer, and the pitch between adjacent convex parts is 0.07-1 micrometer, The Claim 1 or 2 characterized by the above-mentioned. The light-emitting device of description.   The said optical film functions on the side which has a fine uneven | corrugated shape so that the difference in refractive index with an air layer may be less than 0.1. Light-emitting device.   Curing of resin including at least one selected from the group consisting of silicone resin, epoxy resin, oxetane resin, acrylate resin, acrylic resin, polycarbonate, cyclic polyolefin, polyimide, polyolefin, phenol resin, and urethane resin. The light-emitting device according to claim 1, wherein the light-emitting device is formed of an object.   6. The light emitting device according to claim 1, wherein a thickness of the sealing adhesive layer between the optical film and the semiconductor light emitting element is in a range of 100 to 800 μm.   The light emitting device according to claim 1, wherein a refractive index of the sealing adhesive layer is in a range of 1.4 to 2.5.   The light emitting device according to any one of claims 1 to 7, wherein the sealing adhesive layer contains a phosphor.   9. The light emitting device according to claim 8, wherein the phosphor includes at least one selected from the group consisting of oxide phosphors, nitride phosphors, oxynitride phosphors, and sulfide phosphors.   A sealing film laminate comprising: an optical film having a fine uneven shape on a surface; and an adhesive sheet bonded to a smooth surface of the optical film.   The height of the fine uneven | corrugated shaped convex part of the said optical film is 0.07-1 micrometer, The pitch between adjacent convex parts is 0.07-1 micrometer, It is characterized by the above-mentioned. Sealing film laminate.   The adhesive sheet is obtained from silicone resin, epoxy resin, oxetane resin, acrylate resin, acrylic resin, polycarbonate, cyclic polyolefin, polyimide, polyolefin, phenol resin, urethane resin, and a mixture containing at least one of these resins. The sealing film laminated body of Claim 10 or 11 characterized by the above-mentioned.   The thickness of the said adhesive agent sheet is the range of 100-800 micrometers, The sealing film laminated body of any one of Claims 10-12 characterized by the above-mentioned.   The sealing film laminate according to claim 10, wherein the adhesive sheet contains a phosphor.   The sealing film laminated body of any one of Claims 10-14 with which the dicing tape is further laminated | stacked on the surface of the side which has the fine uneven | corrugated shape of the said optical film. The adhesive sheet surface of the sealing film laminate according to any one of claims 10 to 15, a wafer on which a plurality of semiconductor light emitting elements are formed, and a light extraction side surface of the adhesive sheet surface A process of bonding so as to contact each other;
A method of manufacturing a light emitting device, comprising: dicing the wafer bonded to the sealing film laminate together with the optical film and the adhesive sheet into chips.   The method for manufacturing a light-emitting device according to claim 16, further comprising a step of heating and curing the adhesive sheet after forming the chip.   A light emitting device comprising: a light emitting device including a semiconductor light emitting element; an optical film having a fine uneven shape on a surface thereof, and an optical refractive index on the light emitting device side of the interface being controlled. .   The height of the fine uneven-shaped convex part of the said optical film is 0.07-1 micrometer, The pitch between adjacent convex parts is 0.07-1 micrometer, It is characterized by the above-mentioned. Light emitting device.

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