JP2016162811A - Light-emitting device and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device capable of solving the problem of light absorption by a protective element or disconnection of a wire connection part.SOLUTION: The light-emitting device includes: a substrate 10; a light-emitting element 20, disposed on the substrate 10; a protective element 50 or a wire 60, electrically connected to the light-emitting device 20; and a light reflection part 70, formed by three-dimensional molding. The light reflection part 70 is so formed as to cover at least part of the protective element 50 or at least part of the wire 60.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to a light emitting device and a method for manufacturing the light emitting device.

Conventionally, a reflective filler material is disposed between the semiconductor chip in the cavity and the side wall of the cavity, and at least one surface toward the front surface of the base casing is curved in a concave mirror shape or concave shape when viewed from the semiconductor chip. A light-emitting device that forms a reflector surface for a part of radiation has been known (Patent Document 1). By covering the connecting portion of the wire with a reflective filling material, disconnection of the wire can be suppressed.
On the other hand, a method of forming a reflector portion on a lead frame of a light emitting device by three-dimensional modeling by laser sintering is known (Patent Document 2).
In addition, as a countermeasure against disconnection due to environmental changes such as ambient temperature and humidity of the metal wire used in the light emitting device, the metal wire is pushed along the surface of each of the light emitting element and the substrate on which the light emitting element is arranged. A light-emitting device that is deformed and wired is known (Patent Document 3).

JP 2004-40099 A JP 2012-162025 A JP 2013-149927 A

In patent document 1, since the recessed part which accommodates a light emitting element was formed and the light reflection resin was filled using the recessed part, the connection part of a wire was coat | covered, and the level | step difference was required. As a result, the light emitting device size is larger than when there is no recess, and the height of the light emitting device itself is also increased.
In Patent Document 2, a reflector is formed on a substrate by three-dimensional modeling using slice data. As a result, a great deal of time was required to complete the reflector portion.
In Patent Document 3, the metal wire is wired by being deformed by a pressing die so as to follow the surface of each of the light emitting element and the substrate on which the light emitting element is arranged. As a result, the loop portion of the metal wire contacts between the metal wire and the light emitting element, and the substrate on which the light emitting element is disposed, thereby causing non-lighting due to the short mode and conduction resistance due to partial metal wire contact. There is concern about the rise.

  Accordingly, a method for manufacturing a light-emitting device with reduced production time is provided. It is another object of the present invention to provide a light emitting device capable of solving light absorption by a protective element or wire connection disconnection.

An embodiment according to the present invention includes a first step of placing a semiconductor element on a substrate, and a second step of forming a light reflecting portion on the substrate by three-dimensional modeling after the first step. It is a manufacturing method.
Further, another embodiment according to the present invention includes a substrate, a light emitting element disposed on the substrate, a protective element or a wire electrically connected to the light emitting element, and a light reflecting portion formed by three-dimensional modeling. And the light reflecting portion is formed so as to cover at least part of the protective element or at least part of the wire.

According to the embodiment of the present invention, a method for manufacturing a light emitting device with reduced creation time is provided. In addition, it is possible to provide a light emitting device that can solve the problem of disconnection of the wire connection portion.

It is a schematic top view which shows the wiring board which concerns on 1st Embodiment. It is a schematic sectional drawing in the AA of FIG. 1A. It is a schematic top view which shows the wiring board which concerns on one Embodiment. It is a schematic sectional drawing in the BB line of FIG. 1C. It is a schematic top view which shows the wiring board which concerns on 2nd Embodiment. It is a schematic sectional drawing in the CC line of FIG. 2A. It is a schematic sectional drawing which concerns on the modification of FIG. 2A. It is a schematic top view which shows the wiring board which concerns on one Embodiment. It is a schematic sectional drawing in the DD line of FIG. 2D. It is a schematic top view which shows the wiring board which concerns on 3rd Embodiment. It is a schematic sectional drawing in the EE line of FIG. 3A. It is a schematic sectional drawing which concerns on the modification of FIG. 3A. It is a schematic sectional drawing which concerns on the modification of FIG. 3A.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated, referring attached drawing. However, the embodiments shown below exemplify a light emitting device and a method for manufacturing the light emitting device for embodying the technical idea of the present invention, and the present invention describes the method for manufacturing the light emitting device and the light emitting device as follows. It is not limited.

Further, the present specification by no means specifies the member shown in the claims as the member of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention only to the extent that there is no specific description. It is just an example. It should be noted that the size and positional relationship of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate.

<First Embodiment>
FIG. 1A is a top view of the light emitting device 100 according to the first embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view taken along line AA of FIG. 1A. 1C is a modified example in which the position and shape of the light reflecting portion 70 in FIG. 1A are changed, and FIG. 1D is a schematic cross-sectional view taken along the line BB in FIG. 1C.

  The light emitting device 100 according to this embodiment includes a substrate 10, a light emitting element 20 disposed on the substrate 10, a protection element 50 disposed on the substrate 10, a substrate 10, the light emitting element 20, and a substrate 10 and a protection element. 50 and the wire 60 which electrically connects each.

The substrate 10 is a member on which the light emitting element 20 is placed, and includes a molding member 80 and a lead frame 90. The lead frame 90 is provided in at least a pair so that it can function as a terminal of the light emitting device, and is electrically connected to the electrode of the light emitting element 20. The substrate 10 has a recess for mounting the light emitting element 20, and a pair of lead frames 90 are exposed on the bottom surface of the recess.
The light emitting element 20 is placed on the surface of the lead frame 90 exposed on the bottom surface of the concave portion of the substrate 10 via a bonding member, and the positive and negative electrodes of the light emitting element 20 and the upper surface of the lead frame 90 are It is electrically connected via a wire 60.

  Here, in the first embodiment, the lead frame 90 is disposed on the upper surface of the substrate 10 (the upper surface of the lead frame 90) at a position where the wire 60 is bonded (that is, a bonding position between the substrate 10 and the wire 60). The light reflecting portion 70 is formed by three-dimensional modeling so as to cover the joint portion between the wire 60 and the wire 60. A part of the wire 60 is embedded in the light reflecting portion 70.

  In this way, the light reflecting portion 70 is three-dimensionally shaped so as to cover the upper surface of the substrate 10 and the portion where the wire 60 is bonded, thereby reinforcing the bonding portion of the wire, and the ambient temperature and humidity applied to the light emitting device 100. The disconnection of the wire 60 caused by the stress generated by the expansion and contraction of the sealing member 30 due to the environmental change can be suppressed.

(Method for manufacturing light emitting device 100)
The manufacturing method of the light emitting device according to the present embodiment includes a first step of placing the light emitting element 20 and / or the protective element 50 as a semiconductor element on the substrate 10, and a three-dimensional pattern on the substrate 10 after the first step. A second step of forming the light reflecting portion 70 by modeling.
Thus, since the light reflecting part 70 is formed by three-dimensional modeling after the light emitting element 20 is placed, the light emitting element 20 and the light reflecting part 70 can be disposed close to each other. In addition, the light reflecting portion 70 is preferably formed so as to cover the protection element 50. Thereby, light absorption by the protection element 50 can be suppressed.

Moreover, it has the 3rd process of connecting the wiring of the semiconductor element mounted in the 1st process, and a board | substrate with the wire 60 between a 1st process and a 2nd process, and the light reflection part 70 is in a 2nd process. You may form so that the junction location of a board | substrate and the wire 60 may be covered. If at least the bonding portion is covered, the bonding portion of the wire is reinforced, and the stress generated by the expansion and contraction of the sealing member 30 due to the environmental change such as ambient temperature and humidity applied to the light emitting device 100 is caused. Disconnection of the wire 60 can be suppressed.
In addition, after the light emitting element 20 and the wire 60 are electrically connected, only the joint portion between the wire 60 and the lead frame 90 can be covered with the light reflecting portion 70.

Hereinafter, the constituent members of the light emitting device 100 will be described in detail.
(Substrate 10)
As shown in FIG. 1A, the substrate 10 has a portion on which the light emitting element 20 is placed and a portion electrically connected to the wire 60 on the surface thereof. A lead frame 90 serving as a conductive member.

  The board | substrate 10 is good also as a recessed part shape as shown to FIG. 1A and FIG. 1C as a whole, or good also as a shape which has flat form. When the light emitting element 20 is placed inside the recess, the recess is preferably a recess having an opening substantially at the center of the substrate 10, and is provided in a size that allows the light emitting element 20 to be placed on the bottom surface of the recess. preferable.

  The light emitting element 20 can be fixed by a fixing member such as a resin such as epoxy or silicone, a conductive paste such as silver, gold or palladium, or a brazing material such as a metal having a low melting point.

  The light emitting element 20 is electrically connected to the substrate 10. One of the preferable connection forms is to connect the upper surface of the lead frame 90 which is a conductive member and the electrode of the light emitting element 20 with a wire 60 as shown in the figure. The wire 60 may be made of various materials such as a metal having electrical conductivity. Preferably, it consists of gold, copper, aluminum, a gold alloy, a silver alloy, or the like.

  The lead frame 90 is formed using a good electrical conductor such as iron, phosphor bronze, copper alloy, or a clad material. Further, if necessary, for example, silver, aluminum, copper and gold can be plated with a metal for the purpose of improving the reflectance.

  A plating layer consists of metal plating selected from silver, gold | metal | money, nickel, palladium, copper, tin etc., or alloy plating which combined these, for example. Preferably, silver having high reflectivity or gold having good adhesion to the wire is selected. The plating layer can be formed by forming the substrate 10 and then forming it by electrolytic plating.

(Light emitting element 20)
As the light emitting element 20, an element called a so-called light emitting diode is preferably used. For example, a stacked structure including a light emitting layer is formed on a substrate by various semiconductors such as nitride semiconductors such as InN, AlN, GaN, InGaN, AlGaN, and InGaAlN, III-V compound semiconductors, II-VI compound semiconductors, and the like. What was formed is mentioned.
The light-emitting element 20 can be a face-up structure in which the positive and negative electrodes are placed on the substrate 10 so that the positive and negative electrodes are positioned on the upper side, and the positive and negative electrodes are placed on the substrate 10 side. A face-down structure can also be used. Moreover, the thing of the vertical structure which can take conduction | electrical_connection from an up-down direction can also be used. The size of the light emitting element 20 is not particularly limited. Further, the number of the light emitting elements 20 may be one or a plurality may be used. When using a plurality, they may all be of the same type or different types.

(Protective element 50)
The protection element 50 may be any known element mounted on the light emitting device. For example, an element capable of short-circuiting a reverse voltage applied to the light-emitting element or short-circuiting a forward voltage higher than a predetermined voltage higher than the operating voltage of the light-emitting element, that is, overheating, overvoltage, overcurrent Examples thereof include an element having a function of protecting from damage caused by the above, an electrostatic protection element, and the like. Specifically, a Zener diode, a transistor diode, or the like can be used.

(Light reflection part 70)
As illustrated in FIG. 1A, the light reflecting portion 70 is formed so that a wire 60 that electrically connects the substrate 10 and the light emitting element 20 is embedded or partially covered by a three-dimensional modeling method. Further, disconnection of the wire 60 due to stress generated by expansion and contraction of the sealing member 30 due to environmental changes such as ambient temperature and humidity can be suppressed.

The molding method of the light reflecting portion 70 by three-dimensional modeling is selected from, for example, a case where a resin material using an ink jet method or a heat melting method such as a 3D printer is used, and a case where a metal material using a powder sintering method is used. It is preferably formed of at least one kind.
As a material for the light reflecting portion 70, for example, it is preferable to use a material in which various fillers are added to a transparent thermosetting resin or thermoplastic resin and the physical properties and colors are adjusted according to the use.

As described above, the material of the light reflecting portion 70 made of a resin material using an inkjet method or a thermal melting method includes a resin composition of a resin and a filler. Examples of the resin include thermosetting resins, thermoplastic resins, modified resins thereof, or hybrid resins containing one or more of these resins. Specifically, epoxy resin, modified epoxy resin (silicone modified epoxy resin, etc.), silicone resin, modified silicone resin (epoxy modified silicone resin, etc.), hybrid silicone resin, polyimide (PI), modified polyimide resin, polyamide (PA) , Polyethylene terephthalate resin, polycyclohexane terephthalate resin, acrylic resin, polypropylene (PP), polyphthalamide (PPA), polycarbonate (PC), polyphenylene sulfide (PPS), polysulfone (PSF), polyethersulfone (PES), modified Polyphenylene ether (m-PPE), polyetheretherketone (PEEK), polyetherimide (PEI), liquid crystal polymer (LCP), ABS resin, phenol resin, acrylic resin , PBT resin, urea resin, BT resin, polyurethane resin, polyacetal (POM), ultrahigh molecular weight polyethylene (UHPE), fluorocarbon resins.
Among these, a thermoplastic polycarbonate (PC) resin and a nylon resin containing polyphthalamide (PPA) as a component are preferable in terms of transparency, heat resistance, and light resistance. Examples of the resin curing system include photocuring, heat curing, melting and curing.

Inorganic materials used as fillers can be used as reflectors, diffusers or light scattering materials, such as barium sulfate, titanium dioxide, aluminum oxide, silicon oxide, etc., glass cloth, glass fiber, wollastonite etc. for obtaining strength The fibrous filler, carbon for imparting conductivity, silicon oxide, aluminum nitride for imparting heat dissipation, zirconium oxide, zirconium nitride, titanium nitride, or a mixture thereof.
Resin and filler are blended and used according to the purpose.

  The material of the light reflecting portion 70 made of a metal material using a metal sintering method is formed of at least one selected from the group consisting of stainless steel, tool steel, superalloy, nonmagnetic alloy, noble metal and alumina. Is preferred.

  By forming the light reflecting portion 70 by three-dimensional modeling, it is possible to realize a shape that is difficult to form by a general resin material application method such as potting or dispensing. In addition, the time required for the resin to cure can be shortened compared to potting or dispensing. In the present embodiment, the joint portion between the lead frame 90 and the wire 60 is formed in a substantially hemispherical shape with the center as the center, but may be formed so as to form a flat reflecting surface, for example.

The light emitting element 20 and the lead frame 90 are electrically joined by a wire 60. At this time, as shown in FIG. 1A, it is preferable that the wire 60 and the lead frame 90 are joined a plurality of times while being shifted in position.
For example, in the light emitting device 100 of FIG. 1A, the wire 60 that connects the electrode of the light emitting element 20 and the lead frame 90 is bonded at two positions so as to shift the bonding position with the lead frame 90. Is covered with the light reflecting portion 70. A part of the wire 60 between the joint portions is exposed from the light reflecting portion 70.

(Sealing member 30)
The recess inside the substrate 10 is preferably filled with a sealing member 30 as shown in FIG. 1B. For ease of explanation, the sealing member is omitted in FIG. 1A.

  The material of the sealing member 30 is, for example, a thermoplastic resin or a thermosetting resin. Among thermosetting resins, it is preferably formed of at least one selected from the group consisting of epoxy resins, modified epoxy resins, silicone resins, modified silicone resins, acrylate resins, and urethane resins, particularly epoxy resins and modified epoxy resins. Silicone resins and modified silicone resins are preferred.

  The sealing member 30 can be mixed with at least one selected from the group consisting of a filler, a diffusing material, a pigment, a fluorescent material, and a reflective material in order to have a predetermined function. The sealing member 30 may contain a diffusing material. As a specific diffusion material, barium titanate, titanium oxide, aluminum oxide, silicon oxide, or the like can be suitably used. Further, for the purpose of cutting an undesired wavelength, the sealing member 30 can contain an organic or inorganic coloring dye or coloring pigment. Furthermore, the sealing member 30 can also contain a fluorescent material that absorbs light from the light emitting element 20 and converts the wavelength.

  FIG. 1C is a modification of the light emitting device 100 of the present embodiment, and FIG. 1D is a schematic cross-sectional view taken along the line BB1000 of FIG. 1C. The light emitting device 200 shown in FIG. 1C is bonded at two positions by shifting the position similarly to the light emitting device 100, and the two bonding regions are covered with one light reflecting portion 70 as shown in FIG. 1A. This is different from the light emitting device 100 shown in FIG. Other portions can be configured substantially in the same manner as the light emitting device 100, and the same effects can be obtained.

Second Embodiment
2A is a top view of the light emitting device 300 according to the second embodiment, and FIG. 2B is a schematic cross-sectional view taken along the line CC of FIG. 2A. In the present embodiment, as shown in FIG. 2A, the light reflecting portion 70 covers the protection element 50 disposed on the upper surface of the substrate 10 and the wire 60 that electrically connects the substrate 10 and the protection element 50. Has been. The light reflecting portion 70 is formed by three-dimensional modeling. Since the protection element 50 and the wire 60 connecting the protection element are completely covered by the light reflecting portion 70, light absorption by the protection element and the wire can be suppressed.
The light reflecting portion 70 may be provided in contact with the protective element and the wire as shown in FIG. 2B, or may be hollow so that the inside becomes a hollow as shown in FIG. 2C. And may be formed so as to be separated from the protective element and the wire.

  Thus, by forming the light reflecting portion 70 three-dimensionally so as to cover the protection element 50 disposed on the upper surface of the substrate 10 and the wire 60 that electrically connects the substrate 10 and the protection element 50, The disconnection of the wire 60 due to the stress generated by the expansion and contraction of the sealing member 30 due to environmental changes such as ambient temperature and humidity applied to the light emitting device 100 can be suppressed.

  Moreover, since the sealing member 30 does not come into direct contact with the wire 60 by making the inside hollow as shown in FIG. 2C, the disconnection of the wire 60 due to stress can be eliminated.

FIG. 2D is a modification of the light emitting device 300 according to the second embodiment, and FIG. 2E is a cross-sectional view taken along the line DD of FIG. 2D. The light emitting device 400 shown in FIG. 2D is the same as the light emitting device 300 in FIG. 2A in that the protective element 50 and the wire 60 connecting the protective elements are completely covered by the light reflecting portion 70. Has the same effect.
The light emitting device 400 shown in FIG. 2D is different from the light emitting device 300 shown in FIG. 2A in that the light reflecting portion 70 is formed in an island shape apart from the forming member 80 of the substrate 10.
As described above, the stress caused by the thermal contraction of the sealing member 30 can be reduced by covering the protective element 50 and the wire 60 connecting the protective element 50 and separating the protective element 50 from the side wall of the concave portion of the cavity.

<Third Embodiment>
FIG. 3A shows a light emitting device 500 formed according to the third embodiment. In this embodiment, as shown in FIG. 3A and FIG. 3B, which is a cross-sectional view thereof, the protection element 50 disposed on the upper surface of the substrate 10 and the wire 60 that electrically connects the substrate 10 and the protection element 50. The light reflecting portion 70 is formed by three-dimensional modeling so as to surround the periphery of the. The manufacturing method of the light emitting device 500 includes a first step of placing a semiconductor element (the light emitting element 20 and / or the protective element 50) on the substrate 10, and a three-dimensional modeling on the substrate 10 after the first step. A second step of forming the reflection portion 70.
Thus, the light reflecting portion 70 can be formed in the vicinity of the place where the semiconductor element is placed while securing a region necessary for placing the semiconductor element. For example, the distance between the light emitting element 20 and the light reflecting portion 70 can be about 10 to 200 μm.

As shown in FIG. 3A, the light reflecting portion 70 is formed in a wall shape so as to divide the mounting region of the light emitting element and the mounting region of the protection element. It is preferable to change the height of the light reflecting portion 70 in accordance with the thickness of the light emitting element 20 mounted at about 50 to 400 μm.
From another point of view, the height of the light reflecting portion 70 is preferably about 0.1 to 1.5 times the height from the lower surface to the upper surface of the cavity of the substrate 10, thereby controlling the light distribution. It can be expected to suppress yellow ring and reduce emission color unevenness.

  By forming the light reflecting portion 70, the light reflected from the light emitting element is reflected by the light reflecting portion 70 before the light from the light emitting element 20 reaches the protective element 50 and the wire 60 connecting the protective elements, and the protective element 50. And the light absorption by the wire 60 which connects a protection element can be suppressed. The light reflecting portion 70 may be formed so that the mounting surface of the light emitting element and the surface (reflecting surface) extending in the height direction of the light reflecting portion 70 are substantially perpendicular as shown in FIG. 3B. As shown in 3C, the surface (reflecting surface) extending in the height direction of the light reflecting portion 70 may be inclined with respect to the mounting surface of the light emitting element.

  As described above, the light reflecting portion 70 is formed so as to cover the upper surface of the substrate 10, the protective element 50 disposed on the upper surface of the substrate 10, and the wire 60 that electrically connects the substrate 10 and the protective element 50. Dimensional modeling. Thereby, the light reflection part 70 functions as an anchor, the expansion and contraction of the sealing member 30 due to environmental changes such as ambient temperature and humidity applied to the light emitting device 100 are suppressed, and the disconnection of the wire 60 can be suppressed. .

  Further, as shown in FIG. 3C, it is also possible to form a reflector at the same time as the stress relieving to the disconnection of the wire 60 by the light reflecting portion 70.

Further, as shown in FIG. 3D, the light reflecting portion 70 may not be connected to the inner wall surface of the cavity of the substrate 10, or a plurality of light reflecting portions 70 (70A, 70B) may be formed.
Also in the light emitting device 600, disconnection of the wire 60 caused by stress generated by expansion and contraction of the sealing member 30 due to environmental changes such as ambient temperature and humidity can be suppressed.

  In the above-described embodiment, the lead frame is used, but a substrate using ceramic or glass epoxy may be used. In the above-described embodiments, the semiconductor element is a light emitting element or a protective element, but other semiconductor elements such as a capacitor may be used.

  The light-emitting device of the present embodiment includes a liquid crystal display backlight source, various lighting fixtures, a large display, various displays such as advertisements, destination guides, and an image reading device in a digital video camera, facsimile, copier, scanner, etc. It can be used for projector devices.

100, 200, 300, 400, 500, 600 Light emitting device 10 Substrate 20 Light emitting element 30 Sealing member 50 Protection element 60 Wire 70, 70A, 70B Light reflecting portion

Claims (12)

A first step of placing a semiconductor element on a substrate;
After the first step, a second step of forming a light reflecting portion on the substrate by three-dimensional modeling, a method for manufacturing a light emitting device. The method for manufacturing a light emitting device according to claim 1, wherein the semiconductor element is a light emitting element. The method for manufacturing a light emitting device according to claim 1, wherein the semiconductor element is a protective element. The method of manufacturing a light emitting device according to claim 1, wherein the semiconductor element is a light emitting element and a protective element. The method for manufacturing a light emitting device according to claim 3, wherein the light reflecting portion is formed so as to cover the protection element. A third step of connecting the semiconductor element and the wiring of the substrate with a wire between the first step and the second step;
6. The method for manufacturing a light emitting device according to claim 1, wherein in the second step, the light reflecting portion is formed so as to cover a joint portion between the substrate and the wire. A substrate,
A light emitting device disposed on the substrate;
A protective element or wire electrically connected to the light emitting element;
A light reflecting portion formed by three-dimensional modeling,
The light reflecting unit is a light emitting device formed to cover at least a part of the protective element or at least a part of the wire. The light emitting device according to claim 7, wherein the light reflecting portion is made of a resin material. The light emitting device according to claim 7, wherein the light reflecting portion is made of a metal material. The light emitting device according to claim 7, wherein the protective element is embedded by the light reflecting portion. The light emitting device according to claim 7, wherein the light reflecting portion has a hollow area. The light-emitting device according to claim 7, wherein the light reflecting portion covers a joint portion between the substrate and the wire.

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