JP6139427B2 - Light emitting device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a light emitting device mounted on an ultraviolet light irradiation device or the like and a manufacturing method thereof, and more particularly to a light emitting device using a light emitting element such as an LED (Light Emitting Diode) and a manufacturing method thereof.

  2. Description of the Related Art Conventionally, an ultraviolet light irradiation device is used to cure an ultraviolet curable resin used as an adhesive around an FPD (Flat Panel Display) and an ultraviolet curable ink used as an ink for offset sheet-fed printing.

  As an ultraviolet light irradiation device, a lamp type irradiation device using a high-pressure mercury lamp, a mercury xenon lamp, or the like as a light source has been known in the past. However, in recent years, there has been a demand for reduction in power consumption, longer life, and downsizing of the device size. Therefore, in place of the conventional discharge lamp, an ultraviolet light irradiation device using an LED (Light Emitting Diode) as a light source has been developed (for example, Patent Document 1).

  The ultraviolet light irradiation device described in Patent Document 1 includes a plurality of LED modules arranged in a line. Each LED module includes an LED chip having a peak wavelength in the ultraviolet region (generally referred to as “die” or “LED”), a submount substrate, a frame, and the like. It is bonded and fixed on the submount substrate with a die bond agent.

  The die bond agent is a bonding material used for fixing the LED chip to a substrate or the like, and generally, a silicone-based die bond agent, an epoxy-based die bond agent, a metal adhesive, a silver (Ag) paste, or the like is used. However, for example, it is inexpensive, has high heat resistance and moisture resistance, and has a lower elastic modulus than solder, so that an Ag epoxy type or Ag polyimide type so-called Ag paste is used. There are many. However, it has been pointed out that when an optical semiconductor element such as an LED chip is fixed with Ag paste, the reliability is lowered by so-called Ag ion migration (for example, Non-Patent Document 1).

  As described in Non-Patent Document 1, Ag ion migration is a kind of electrochemical migration phenomenon of metal, and is a phenomenon in which Ag migrates and grows in the form of spots or dendrites due to electrolysis. When Ag is ionized and grows in this way, it finally comes into contact with the LED chip electrodes and bonding wires, and in the worst case, the LED chip electrodes (that is, between the anode and cathode) are short-circuited. It becomes. When the electrodes of the LED chips are short-circuited, the LED chips are not turned on or destroyed.

  As described above, Ag ion migration is caused by the ionization of Ag. In particular, in an optical semiconductor element such as an LED chip that emits light, there is a concern that Ag may be ionized by surface plasmons (for example, Patent Document 3). ). As described in Patent Document 3, when the metal particles are irradiated with light, surface plasmons are generated, the electric field strength of the portion is locally increased, and the metal particles are ionized. That is, in a configuration in which an optical semiconductor element such as an LED chip is fixed with Ag paste, surface plasmon is generated when light from the LED chip enters the Ag paste, and Ag contained in the Ag paste is ionized. Then, when Ag grows in a spot shape or a dendritic shape due to ionization of Ag, there is a problem that eventually the electrodes of the LED chip are short-circuited and the LED chip is not lit or destroyed.

JP 2011-146646 A JP 2013-243316 A JP 2008-070187 A

"Reliability Handbook", Renesas Technology Corp., Rev. 1.01, November 28, 2008, p. (4-25)-(4-27)

  In order to solve such a problem of Ag ion migration, it is effective to set a long distance of movement of Ag when Ag is generated by Ag ion migration in advance or to reduce the electric field strength between patterns. In general, measures are taken such as securing a sufficient insulation distance between the Ag paste and each electrode or bonding wire of the LED chip adjacent thereto. However, in the case of a configuration in which LED chips are arranged at high density (that is, an LED module) as in the configuration described in Patent Document 1, it is difficult to ensure a sufficient insulation distance due to restrictions on arrangement. .

  In addition, Ag ion migration is induced when the Ag contained in the Ag paste is ionized by the light from the LED chip, so that the light from the LED chip does not enter the Ag paste (that is, the generation of surface plasmons). In order to suppress this, it may be possible to apply a coating or the like on the Ag paste that blocks light from the LED chip, but it is extremely difficult to apply the coating or the like after the LED chip is bonded and fixed on the substrate.

  The present invention has been made in view of such circumstances. The object of the present invention is to suppress Ag ion migration with a simple configuration without applying coating or the like on Ag paste, and at a high density. A light-emitting device that can be mounted and a method for manufacturing the same.

In order to achieve the above object, a light emitting device of the present invention includes a substrate, a conductive pattern portion formed on the surface of the substrate, and placed on the surface of the pattern portion to emit light from the light emitting layer from the emission surface. A first recessed portion having a first opening that is slightly larger than the emitting surface of the LED chip is formed on the surface of the pattern portion. It is accommodated in the recess and bonded to the bottom surface of the first recess via a die bond agent containing at least a silver component, and the transmittance is at least in the wavelength region of light in the gap between the first recess and the LED chip. A low shading means is provided .

  According to such a configuration, even if part of the ultraviolet light emitted from the LED chip returns as return light, the periphery of the LED chip and the periphery of the die bond agent are provided with a slight gap therebetween. Since it is surrounded by the wall surface of the concave portion 1, there is almost no return light reaching the die bond agent, and the occurrence of Ag ion migration is suppressed. Therefore, in order to solve the problem of Ag ion migration, it is not necessary to take measures such as securing a sufficient insulation distance between the die bond agent and each electrode or bonding wire of the LED chip adjacent to the die bond agent. High density mounting is possible.

From another point of view, the light-emitting device of the present invention is a substrate, a conductive pattern portion formed on the surface of the substrate, and a light-emitting surface that is placed on the surface of the pattern portion and emits light from the light-emitting layer. A first concave portion having a first opening that is slightly larger than the emission surface of the LED chip is formed on the surface of the pattern portion. And is bonded to the bottom surface of the first recess via a die bond agent containing at least a silver component, and is formed so as to protrude from the edge of the first opening toward the LED chip. Further, it is characterized by further comprising a light shielding member that shields light at least in the wavelength region of light. In this case, the light shielding member can be configured to be formed integrally with the pattern portion.

Moreover, it is desirable that the emission surface and the first opening of the LED chip have a rectangular shape, and each side of the first opening is configured to be 5 to 20% larger than each side of the emission surface of the LED chip.
Further, when the depth of the first recess is d, the distance from the light emitting layer to the bottom surface of the first recess is t1, and the film thickness of the die bond agent is t2,
t2 <d <t1
It is desirable to satisfy the relationship.

  In addition, a second recess having a second opening slightly larger than the first opening is formed on the surface of the substrate, and the first recess is formed inside the second recess. Can be configured.

  In addition, a third recess having a third opening smaller than the emission surface of the LED chip is formed on the bottom surface of the first recess, and the die bonding agent is accommodated in the third recess. can do. According to such a configuration, it is possible to reliably prevent the return light from reaching the die bond agent, and thus it is possible to reliably suppress the occurrence of Ag ion migration.

  Further, the LED chip has a cathode terminal and an anode terminal on the emission surface side, the substrate is a conductive metal substrate, and the pattern portion can be formed integrally with the metal substrate. it can.

  Further, the LED chip can be configured to have a cathode terminal and an anode terminal on the emission surface side, and the substrate to have an insulating property.

  Further, the LED chip has either a cathode terminal or an anode terminal on the emission surface side, and has either the other on the bottom surface side of the first recess, and the substrate is configured to have insulating properties. Can do.

  Further, the LED chip has either one of a cathode terminal or an anode terminal on the emission surface side, and has either the other on the bottom surface side of the first recess, and the substrate is a metal substrate having conductivity, The metal substrate can be configured to include an insulating layer that electrically insulates the pattern portion.

  Moreover, it is desirable that the light emitted from the LED chip includes light in the ultraviolet wavelength region.

From another point of view, a method for manufacturing a light emitting device according to the present invention includes a substrate and an LED chip that is mounted on the substrate and emits light from the light emitting layer from an emission surface. A method for producing a conductive pattern portion on a substrate, a step of forming a recess having an opening slightly larger than an emission surface of the LED chip on the surface of the pattern portion, and a bottom surface of the recess In addition, a step of applying a die bond agent containing at least a silver component, a step of housing the LED chip in the recess, bonding the LED chip and the bottom surface of the recess with the die bond agent, and a gap between the recess and the LED chip, Filling with a light shielding material having a low transmittance at least in the wavelength region of light .
From another point of view, a method for manufacturing a light emitting device according to the present invention includes a substrate and an LED chip that is mounted on the substrate and emits light from the light emitting layer from an emission surface. A method for producing a conductive pattern portion on a substrate, a step of forming a recess having an opening slightly larger than an emission surface of the LED chip on the surface of the pattern portion, and a bottom surface of the recess The step of applying a die bond agent containing at least a silver component, the step of housing the LED chip in the recess, and bonding the LED chip and the bottom surface of the recess with the die bond agent, and the edge of the opening to the LED chip And a step of arranging a light shielding member that shields light at least in the wavelength region of light so as to protrude toward the surface.
The LED chip may further include a step of providing at least one electrode on the light exit surface side and bonding a wire to the electrode.

  As described above, according to the present invention, a light emitting device that can suppress Ag ion migration with a simple configuration and can be mounted at a high density without applying a coating or the like on an Ag paste and a manufacturing method thereof are realized. .

1 is a plan view of a light emitting device according to a first embodiment of the present invention. It is an expanded sectional view of the A section of FIG. It is a figure explaining the relationship between the LED chip and recessed part of the light-emitting device which concerns on the 1st Embodiment of this invention. It is a flowchart explaining the manufacturing process of the light-emitting device which concerns on the 1st Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 3rd Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 4th Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 5th Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 6th Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 7th Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 8th Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 9th Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 10th Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 11th Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 12th Embodiment of this invention. It is sectional drawing of the light-emitting device which concerns on the 13th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent part in a figure, and the description is not repeated.

(First embodiment)
FIG. 1 is a plan view of a light emitting device 100 according to the first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a part A in FIG. The light emitting device 100 of this embodiment is a device that is mounted on an ultraviolet light irradiation device and emits ultraviolet light. As shown in FIG. 1, a plurality of (10 in FIG. 1) LED chips 110 and the like on a substrate 101. It has.

  The substrate 101 is a so-called wiring substrate made of an insulating base material (for example, ceramic (aluminum nitride, alumina, silicon nitride, silicon carbide, etc.)). As shown in FIG. 1, on the surface of the substrate 101, ten rectangular pattern portions 112 made of a conductive metal material (for example, copper, aluminum), one positive terminal 102, and one Negative electrode terminal 103 is formed. In addition, as shown in FIG. 2, a rectangular opening 112a (first opening) slightly larger than the emission surface 110a of the LED chip 110 is provided at the center of the surface of the pattern portion 112 of the present embodiment. A concave portion 112b (first concave portion) is formed, and a flat portion 112c for hitting the bonding wire 114 is formed around the concave portion 112b (that is, on the outer peripheral edge side of the surface of the pattern portion 112).

  The LED chip 110 has a quadrangular prism shape, and includes a cathode terminal 110b on an upper surface (that is, an emission surface 110a) and an anode terminal 110c on a lower surface. When a current is applied between the anode terminal 110c and the cathode terminal 110b, ultraviolet light (for example, light having a wavelength of 385 nm) is generated in the light emitting layer 110d and emitted from the emission surface 110a. In the present embodiment, the LED chip 110 is accommodated in the recess 112b, and the bottom surface of the recess 112b and the lower surface of the LED chip 110 (that is, the anode terminal 110c) are bonded via the die bond agent 116.

  The die bond agent 116 is a member for mechanically and electrically joining the LED chip 110 and the pattern part 112, and in this embodiment, a conductive silver (Ag) paste is used.

  The cathode terminal 110b of each LED chip 110 is connected via a bonding wire 114 to the flat portion 112c of the pattern portion 112 to which the LED chip 110 adjacent to one side (right side in FIGS. 1 and 2) of the LED chip 110 is bonded. The adjacent LED chips 110 are connected in series. Further, in FIG. 1, the pattern portion 112 to which the leftmost LED chip 110 is bonded is connected to the positive electrode terminal 102 formed on the substrate 101 via the bonding wire 114, and the rightmost LED is located. The cathode terminal 110 b of the chip 110 is connected to the negative terminal 103 formed on the substrate 101 via a bonding wire 114. The positive electrode terminal 102 and the negative electrode terminal 103 are connected to a power supply device (not shown). By applying a current between the positive electrode terminal 102 and the negative electrode terminal 103 by the power supply device, the positive electrode terminal 102 and the negative electrode terminal 103 are connected to each other. A current flows through the plurality of LED chips 110 connected in series therebetween, and ultraviolet light is emitted from each LED chip 110. And the ultraviolet light radiate | emitted from each LED chip 110 passes along the cover glass not shown arrange | positioned above LED chip 110 (namely, in an optical path), and is irradiated toward an irradiation target object (not shown). .

  As described above, the ultraviolet light emitted from each LED chip 110 of the present embodiment passes through the cover glass and reaches the irradiation target, but when the ultraviolet light passes through the cover glass, a part of the ultraviolet light passes through the cover glass. There is a problem that the light is reflected by the incident surface and the light exit surface and returns to the LED chip 110 side. Further, there is a problem that the ultraviolet light emitted from each LED chip 110 is reflected by the irradiation object and returns to the LED chip 110 side. Thus, when the ultraviolet light emitted from each LED chip 110 returns to the LED chip 110 side (hereinafter, the light returning to the LED chip 110 side is referred to as “return light”), the return light is returned. Incident to the die bond agent 116, Ag contained in the die bond agent 116 is ionized, and Ag ion migration is induced. Therefore, in this embodiment, in order to suppress the return light from entering the die bonding agent 116, the recess 112b is formed so as to surround the LED chip 110.

  FIG. 3 is a partially enlarged view of FIG. 2 and is a diagram for explaining the relationship between the LED chip 110 and the recess 112b. As shown in FIG. 3, the upper surface and the lower surface of the LED chip 110 of the present embodiment have a square shape with a side length of a1 (for example, about 1,000 μm), and the opening 112b of the recess 112b is The shape of the square of one side is a2. The length a2 of one side of the opening 112b is slightly larger than the length a1 of one side of the LED chip 110. In this embodiment, the one side of the LED chip 110 is considered in consideration of the size tolerance of the LED chip 110. Is set to be 5 to 20% larger than the length a1. Note that the return light that passes through the gap between the LED chip 110 and the recess 112b and travels toward the die bond agent 116 decreases as the gap between the LED chip 110 and the recess 112b decreases, and thus the length of one side of the opening 112b. It is more preferable that a2 is set to be 5 to 10% larger than the length a1 of one side of the LED chip 110.

Further, in the present embodiment, when the ultraviolet light from the light emitting layer 110d is emitted from the side surface of the LED chip 110 (when there is so-called “side light emission”), the ultraviolet light is converted into the LED chip 110 and the recess 112b. The flat portion 112c is configured to be positioned higher than the die bond agent 116 and lower than the light emitting layer 110d in order to prevent the light from entering the die bond agent 116. That is, when the depth of the recess 112b is d, the distance from the light emitting layer 110d of the LED chip 110 to the bottom surface of the recess 112b is t1, and the thickness of the die bond agent 116 is t2, the following conditional expression (1) is satisfied. It is configured to meet.
t2 <d <t1 (1)

  As described above, when the conditional expression (1) is satisfied, the light emitting layer 110d is disposed outside the concave portion 112b (that is, above the flat portion 112c). Therefore, almost all of the ultraviolet light emitted from the light emitting layer 110d is The light is emitted toward an irradiation object (not shown) arranged above the LED chip 110. As described above, a part of the ultraviolet light emitted from the LED chip 110 is reflected and returned by the irradiation object or the like, but there is a slight gap between the periphery of the LED chip 110 and the periphery of the die bond agent 116. Is surrounded by the wall surface of the recess 112b provided with a gap between the LED chip 110 and the recess 112b so that there is almost no return light toward the die bond agent 116, and the occurrence of Ag ion migration is suppressed. It has become. Thus, the recess 112b of this embodiment functions as a kind of light shielding member that shields the return light toward the die bond agent 116, thereby suppressing the occurrence of Ag ion migration. Therefore, according to the configuration of the present embodiment, in order to solve the problem of Ag ion migration as in the past, the die bond agent 116 and each electrode of the LED chip adjacent thereto (that is, the cathode terminal 110b and the anode terminal 110c). ) And the bonding wire 114 need not be taken, and the LED chip 110 can be mounted on the substrate 101 at a high density.

(Method for manufacturing light emitting device 100)
Next, a method for manufacturing the light emitting device 100 of this embodiment will be described. FIG. 4 is a flowchart for explaining a manufacturing process of the light emitting device 100 of the present embodiment.

(Pattern formation process)
First, a substrate 101 cut to a predetermined size is prepared, and a pattern portion 112 is formed on the surface by a known plating method, thick film method, thin film method, DBC (Direct Bonded Copper), AMC (Active Metal Brazed Copper). To do. A pattern portion 112 is formed.

(Recess formation process)
Next, the central portion of the surface of the pattern portion 112 is shaved by well-known etching, sand blasting, machining, or the like to form the concave portion 112b. In another embodiment, the periphery (that is, the flat portion 112c) of the pattern portion 112 is grown by well-known mask plating, vapor deposition, sputtering, screen printing, or the like, and the recess 112b is formed at the center of the pattern portion 112. Can also be formed.

(Die bond agent coating process)
Next, a predetermined amount of die bond agent 116 is applied to a substantially central portion of the bottom surface of the recess 112b using a dispenser or a transfer pin.

(Joining process)
Next, using a die bonder, a mounter, or the like, the LED chip 110 is mounted at a substantially central portion of the recess 112b, and the lower surface of the LED chip 110 and the bottom surface of the recess 112b are joined by the die bond agent 116.

(Wire bonding process)
Finally, using a wire bonder or the like, the cathode terminal 110b of each LED chip 110 and the flat portion 112c of the pattern portion 112 to which the adjacent LED chip 110 is bonded are connected by the bonding wire 114, and FIG. Among them, the pattern portion 112 to which the LED chip 110 located on the leftmost side is bonded and the positive electrode terminal 102 formed on the substrate 101 are connected by a bonding wire 114, and the cathode terminal 110b of the LED chip 110 located on the rightmost side The negative electrode terminal 103 formed on the substrate 101 is connected by the bonding wire 114, and the light emitting device 100 of this embodiment is completed.

  The above is the description of the embodiment of the present invention. However, the present invention is not limited to the configuration of the above-described embodiment, and various modifications are possible within the scope of the technical idea.

  For example, in the present embodiment, the upper surface and the lower surface of the LED chip 110 are square, and the opening 112b of the recess 112b is also square. However, the shape of the opening 112b of the recess 112b is the LED chip 110. Any shape may be used as long as it is similar to the upper and lower surfaces of the LED chip. In this case, the opening 112b of the recess 112b is 5 to 20% with respect to the upper and lower surfaces (that is, the outer shape) of the LED chip 110, Preferably, it is set to be 5 to 10% larger.

  In the present embodiment, the LED chip 110 has been described as emitting light having a wavelength of 385 nm. However, the LED chip 110 may emit light having a wavelength in the other ultraviolet region, and may have a wavelength in the visible region or infrared region. It may emit light.

(Second Embodiment)
FIG. 5 is a cross-sectional view of a light emitting device 200 according to the second embodiment of the present invention. In the light emitting device 200 of the present embodiment, the substrate 201 is formed of a conductive base material (for example, a metal substrate such as copper or aluminum), and is formed on the surface of the substrate 201 (that is, the substrate 201 and the pattern unit 112). (1) is different from the light emitting device 100 of the first embodiment in that an insulating layer 201a having an insulating property is formed.

As the substrate 201 of the present embodiment is applicable to metal substrates such as, for example, copper or aluminum, as the insulating layer 201a, for _{example, SiO 2, Al 2 O 3} , TiO 2, ZrO 2, ZnO 2, Nb 2 _{O 5, MgO, TaO 2,} HfO, or Y 2 _{O 3} oxide such, SiN, AlN, nitride such as AlON, thin and composed mainly of fluoride MgF ₂ or the like, ceramics, glass epoxy, polyimide Resins such as PEEK (polyetheretherketone) and unilate are applicable. The insulating layer 201a of this embodiment is formed (formed) by a sputtering method, a vapor deposition method, or the like prior to the pattern portion forming step.

  In this manner, when the insulating layer 201a having an insulating property is formed between the substrate 201 and the pattern portion 112, the conductive substrate 201 can be applied to the present invention. In addition, from the viewpoint of efficiently conducting the heat generated in the LED chip 110 to the substrate 201, the insulating layer 201a is made of a material having high thermal conductivity or is made thin, so that the thermal resistance of the insulating layer 201 is lowered. It is preferable to do.

(Third embodiment)
FIG. 6 is a cross-sectional view of a light emitting device 300 according to the third embodiment of the present invention. The light emitting device 300 of this embodiment is different from the light emitting device 200 of the second embodiment in that the insulating layer 201a is partially formed on the surface of the substrate 201 (that is, only directly below the pattern portion 112). .

  As described above, even when the insulating layer 201a is formed only directly below the pattern portion 112, the conductive substrate 201 can be applied to the present invention as in the second embodiment.

(Fourth embodiment)
FIG. 7 is a cross-sectional view of a light emitting device 400 according to the fourth embodiment of the present invention. The light emitting device 400 of the present embodiment has a rectangular recess 401b (second recess) formed on the surface of the substrate 401, and the pattern portion 412 is formed so as to cover the recess 401b. Different from the light emitting device 100 of the embodiment.

  As shown in FIG. 7, the pattern portion 412 of this embodiment is formed of a thin film such that the thickness in the recess 412 b (first recess) and the thickness in the flat portion 412 c are substantially the same. 401b has an opening 401a (second opening) that is slightly larger than the opening 412a (first opening) of the recess 412b formed in the pattern portion 412, and the recess 412b corresponds to the recess 401b. It is formed inside. In addition, the recessed part 401b of this embodiment is formed by sandblasting, laser processing, etc. prior to a pattern part formation process. As another embodiment, as in the second and third embodiments, the substrate 401 is formed of a conductive base material (for example, a metal substrate such as copper or aluminum), and the substrate 401 and the pattern portion 412 are formed. An insulating layer may be formed between the two.

  Thus, even when the surface of the substrate 401 and the surface of the pattern portion 412 are both recessed, as long as the conditional expression (1) is satisfied, the occurrence of Ag ion migration is suppressed as in the first embodiment.

(Fifth embodiment)
FIG. 8 is a cross-sectional view of a light emitting device 500 according to the fifth embodiment of the present invention. The light emitting device 500 of the present embodiment is the light emitting device 100 of the first embodiment in that the gap between the LED chip 110 and the recess 112b is filled with a light shielding material 513 (light shielding means) having a low ultraviolet light transmittance. And different.

  As the light shielding material 513, a material having fluidity is suitable, and for example, a fluorine resin, a silicone resin, a UV curable resin, solder, aluminum, or the like can be used. Moreover, what contained the additive which absorbs ultraviolet light in a fluororesin, a silicone resin, UV curable resin, etc., and the thing containing the additive which reflects an ultraviolet light are also applicable. In addition, the light shielding material 513 of this embodiment is filled in the clearance gap between the LED chip 110 and the recessed part 112b after a joining process.

  As described above, when the light shielding material 513 is filled in the gap between the LED chip 110 and the recess 112b, the return light is absorbed by the light shielding material 513, so that almost no return light reaches the die bonding agent 116 and Ag ion migration occurs. Is further suppressed.

(Sixth embodiment)
FIG. 9 is a cross-sectional view of a light emitting device 600 according to the sixth embodiment of the present invention. The light emitting device 600 of this embodiment is different from the light emitting device 400 of the fourth embodiment in that a light shielding material 613 (light shielding means) having a low transmittance of ultraviolet light is filled in the gap between the LED chip 110 and the recess 412b. Different.
As described above, in the light emitting device 400 of the fourth embodiment as well, similarly to the fifth embodiment, the gap between the LED chip 110 and the recess 412b is filled with the light shielding material 613, thereby further generating Ag ion migration. Can be suppressed.

(Seventh embodiment)
FIG. 10 is a cross-sectional view of a light emitting device 700 according to the seventh embodiment of the present invention. The light emitting device 700 of the present embodiment is provided with a plate-shaped light shielding member 715 (light shielding means) extending from the flat portion 112c of the pattern portion 112 toward the LED chip 110, and the light emitting device 100 of the first embodiment. And different.

  As the light shielding member 715, a material having UV resistance is suitable, for example, colored glass such as Teflon (registered trademark) resin, polyimide, PEEK, ultraviolet cut glass, ND filter, plate-like metal (for example, aluminum, Copper, stainless steel) or the like can be used. In addition, the light shielding member 715 of this embodiment is arrange | positioned so that the clearance gap between the LED chip 110 and the recessed part 112b (namely, opening part 112a) may be filled after a joining process, and the flat part 112c by soldering or a heat resistant adhesive agent Secured on top.

  As described above, when the light shielding member 715 is disposed so as to fill the gap between the LED chip 110 and the recess 112b, the return light is shielded by the light shielding member 715 as in the fifth and sixth embodiments. The return light that reaches the point almost disappears, and the occurrence of Ag ion migration is further suppressed.

(Eighth embodiment)
FIG. 11 is a cross-sectional view of a light emitting device 800 according to the eighth embodiment of the present invention. The light emitting device 800 of the present embodiment is the first in that the concave portion 112bM is formed so that the flat portion 112cM of the pattern portion 112 protrudes toward the LED chip 110 (that is, the opening portion 112aM is narrowed). This is different from the light emitting device 100 of the embodiment.

  As described above, when the flat portion 112cM of the pattern portion 112 is configured to protrude toward the LED chip 110 (that is, the opening portion 112aM is narrowed), the flat portion 112cM functions as a kind of light shielding member. As in the seventh embodiment, almost no return light reaches the die bond agent 116, and the occurrence of Ag ion migration is further suppressed.

(Ninth embodiment)
FIG. 12 is a cross-sectional view of a light emitting device 900 according to the ninth embodiment of the present invention. In the light emitting device 900 of this embodiment, the substrate 901 is made of a conductive base material (for example, a metal substrate such as copper or aluminum), and the conductive pattern portion 112 is formed integrally with the substrate 901. This is different from the light emitting device 100 of the first embodiment. The LED chip 910 is different from the light emitting device 100 of the first embodiment in that the LED chip 910 includes a cathode terminal 910b and an anode terminal 910c on the upper surface (that is, the emission surface 910a).

  The LED chip 910 of this embodiment is an LED chip formed by crystal growth of an epitaxial layer such as GaN on the surface of an insulating substrate (for example, a sapphire substrate) that transmits ultraviolet light. A cathode terminal 910b and an anode terminal 910c are formed. Further, the lower surface of the LED chip 910 is an insulating sapphire substrate. The cathode terminal 910b of each LED chip 910 is connected to the anode terminal 910c of the LED chip 910 adjacent to one side (right side in FIG. 12) of the LED chip 910 via the bonding wire 114, and the adjacent LED chip 910 is Are connected in series.

  As described above, the LED chip 910 using the conductive substrate 901 and having the cathode terminal 910b and the anode terminal 910c on the upper surface (that is, the emission surface 910a) can also be applied to the present invention. In this embodiment, since the bonding wire 114 is not connected to the pattern portion 112, the pattern portion 112 is electrically floating, but the pattern portion 112 is formed integrally with the substrate 901, and the LED chip 910 is formed. It functions as a heat conducting member that efficiently conducts the heat generated in step 1 to the substrate 901.

(Tenth embodiment)
FIG. 13 is a cross-sectional view of a light emitting device 1000 according to the tenth embodiment of the present invention. The light emitting device 1000 of the present embodiment is configured such that the substrate 1001 is made of a conductive base material (for example, a metal substrate such as copper or aluminum), and the substrate 1001 also serves as the pattern portion 412 (that is, the substrate 1001). Is integrally formed with the pattern portion 412), and is different from the light emitting device 400 of the fourth embodiment. Similarly to the ninth embodiment, the LED chip 910 is different from the light emitting device 400 of the fourth embodiment in that a cathode terminal 910b and an anode terminal 910c are provided on the upper surface (that is, the emission surface 910a).

  As described above, the LED chip 910 having the cathode terminal 910b and the anode terminal 910c on the upper surface (that is, the emission surface 910a) is also applied to the present invention by using the substrate 1001 configured to also serve as the pattern portion 412. be able to. Also in this embodiment, as in the ninth embodiment, since the bonding wire 114 is not connected to the pattern portion 412 (that is, the substrate 1001), the pattern portion 412 is electrically floating, but the pattern portion 412 is Since it is formed integrally with the substrate 1001, heat generated in the LED chip 910 can be efficiently conducted to the substrate 901.

(Eleventh embodiment)
FIG. 14 is a cross-sectional view of a light emitting device 1100 according to the eleventh embodiment of the present invention. The light emitting device 1100 of the present embodiment has a rectangular opening 1112c (third opening) that is smaller than the emission surface 110a of the LED chip 110 on the bottom surface of the recess 1112b (first recess) of the pattern part 1112. A recess 1112d (third recess) is formed, and the die bond agent 116 is accommodated in the recess 1112d, which is different from the light emitting device 100 of the first embodiment.

  According to such a configuration, even if the return light passes through the gap between the LED chip 110 and the recess 112b, it does not reach the die bond agent 116, and the generation of Ag ion migration can be reliably suppressed. Note that the recess 1112d can be formed by performing well-known etching, sand blasting, machining, or the like prior to the die bonding agent application step.

(Twelfth embodiment)
FIG. 15 is a sectional view of a light emitting device 1200 according to the twelfth embodiment of the present invention. The light emitting device 1200 of the present embodiment is the light emitting device of the first embodiment in that the rectangular opening 1212a (first opening) of the pattern portion 1212 is formed smaller than the emission surface 110a of the LED chip 110. Different from the device 100.

  As shown in FIG. 15, in the present embodiment, the rectangular opening 1212a (first opening) of the pattern portion 1212 is smaller than the emission surface 110a of the LED chip 110, and the recess 1212b (first recess). Contains only the die bond agent 116 and is fixed in a state where the lower surface of the LED chip 110 is in contact with the flat portion 1212c.

  According to such a configuration, similarly to the eleventh embodiment, it is possible to reliably prevent the return light from entering the die bond agent 116, and thus it is possible to reliably suppress the occurrence of Ag ion migration.

(13th Embodiment)
FIG. 16 is a sectional view of a light emitting device 1300 according to the thirteenth embodiment of the present invention. In the light emitting device 1300 of the present embodiment, a recess 1301b having a rectangular opening 1301a slightly larger than the LED chip 110 is formed on the surface of the substrate 1301, and the pattern portion 1312 is formed only on the bottom surface of the recess 1301b. It differs from the light-emitting device 100 of 1st Embodiment by the point. The substrate 1301 is different from the light emitting device 100 of the first embodiment in that a conductor portion 1305 extending in an L shape from the surface of the substrate 1301 to the pattern portion 1312 is formed in the substrate 1301.

  As in the first embodiment, the substrate 1301 of this embodiment is an insulating wiring substrate, and the conductor portion 1305 has a hole extending in an L shape from the surface of the substrate 1301 to the wall surface of the recess 1301b. The hole is formed by pouring a conductive material such as solder into the hole. And the pattern part 1312 is formed in the bottom face of the recessed part 1301b by mask plating etc. so that it may electrically connect with the conductor part 1305. FIG. In another embodiment, the conductor portion 1305 may be formed by inserting a via into the substrate 1301. Further, when the substrate 1301 is formed of a multilayer laminated substrate, the conductor portion 1305 can be formed by a combination of a wiring pattern and vias of the multilayer laminated substrate.

  In the present embodiment, the LED chip 110 is accommodated in the recess 1301 b, and the pattern portion 1312 and the lower surface of the LED chip 110 (that is, the anode terminal 110 c) are bonded via the die bond agent 116. The cathode terminal 110b of each LED chip 110 is connected via a bonding wire 114 to a conductor portion 1305 to which the LED chip 110 adjacent to one side (right side in FIG. 16) of the LED chip 110 is electrically connected. As in the first embodiment, adjacent LED chips 110 are connected in series.

  As described above, the periphery of the LED chip 110 and the periphery of the die bond agent 116 of the present embodiment are surrounded by the wall surface of the recess 1301 b provided in the substrate 1301. For this reason, as in the first embodiment, there is almost no return light passing through the gap between the LED chip 110 and the recess 1301b and going to the die bond agent 116, and the occurrence of Ag ion migration is suppressed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300 Light emitting device 101, 201, 401, 901, 1001 Substrate 102 Positive electrode terminal 103 Negative electrode terminal 110, 910 LED chip 110a, 910a Emitting surface 110b, 910b Cathode terminal 110c, 910c Anode terminal 110d Light emitting layer 112, 412, 1112, 1212, 1312 Pattern part 112a, 412a, 112aM, 1112a, 1212a, 1301a Opening part (first opening part)
112b, 412b, 112bM, 1112b, 1212b, 1301b Recessed portion (first recessed portion)
112c, 412c, 112cM, 1212c Flat part 114 Bonding wire 116 Die bond agent 201a Insulating layer 401a Opening (second opening)
401b Concave portion (second concave portion)
513,613 Light-shielding material 715 Light-shielding member 1112c Opening (third opening)
1112d recess (third recess)
1305 Conductor part

Claims (15)

A substrate,
A conductive pattern portion formed on the surface of the substrate;
An LED (Light Emitting Diode) chip mounted on the surface of the pattern portion and emitting light from the light emitting layer from the emission surface;
With
A first recess having a first opening slightly larger than the emission surface of the LED chip is formed on the surface of the pattern portion,
The LED chip is housed in the first recess and bonded to the bottom surface of the first recess via a die bond agent containing at least a silver component ;
A light-emitting device, characterized in that light-shielding means having a low transmittance at least in the wavelength region of the light is provided in a gap between the first recess and the LED chip . A substrate,
A conductive pattern portion formed on the surface of the substrate;
An LED chip mounted on the surface of the pattern portion and emitting light from the light emitting layer from an emission surface;
With
A first recess having a first opening slightly larger than the emission surface of the LED chip is formed on the surface of the pattern portion,
The LED chip is housed in the first recess and bonded to the bottom surface of the first recess via a die bond agent containing at least a silver component;
A light shielding member that is formed so as to protrude from the edge of the first opening toward the LED chip and shields light at least in the wavelength region of the light;
A light emitting device characterized by that. The light-emitting device according to claim 2, wherein the light shielding member is formed integrally with the pattern portion. The emission surface of the LED chip and the first opening are rectangular.
4. The light emitting device according to claim 1 , wherein each side of the first opening is 5 to 20% larger than each side of the emission surface of the LED chip. 5. When the depth of the first recess is d, the distance from the light emitting layer to the bottom surface of the first recess is t1, and the film thickness of the die bond agent is t2,
t2 <d <t1
The light emitting device according to any one that satisfies the relationship claim 1, wherein according to claim 4. A second recess having a second opening slightly larger than the first opening is formed on the surface of the substrate,
The first recess, the light emitting device according to any one of claims 5 that claim 1, characterized in that formed inside the second recess. A third recess having a third opening smaller than the emission surface of the LED chip is formed on the bottom surface of the first recess,
The light emitting device according to any one of claims 1 to 6 , wherein the die bond agent is accommodated in the third recess. The LED chip has a cathode terminal and an anode terminal on the emission surface side,
The substrate is a metal substrate having conductivity,
The light emitting device according to any one of claims 1 to 7 , wherein the pattern portion is formed integrally with the metal substrate. The LED chip has a cathode terminal and an anode terminal on the emission surface side,
The substrate-emitting device according to any one of claims 1 to 7, characterized in that it comprises an insulating property. The LED chip has either a cathode terminal or an anode terminal on the emission surface side, and has either the other on the bottom surface side of the first recess,
The substrate-emitting device according to any one of claims 1 to 7, characterized in that it comprises an insulating property. The LED chip has either a cathode terminal or an anode terminal on the emission surface side, and has either the other on the bottom surface side of the first recess,
The substrate is a metal substrate having conductivity,
The metal substrate, the light emitting device according to any one of claims 1 to 7, characterized in that it comprises an insulating layer electrically insulating the said pattern portion. The light emitting device according to any one of claims 1 to 11 , wherein light emitted from the LED chip includes light in an ultraviolet wavelength region. A method of manufacturing a light emitting device including a substrate and an LED (Light Emitting Diode) chip mounted on the substrate and emitting light from the light emitting layer from an emission surface,
Producing a conductive pattern on the substrate;
Forming a recess having an opening slightly larger than the emitting surface of the LED chip on the surface of the pattern portion; and
Applying a die bond agent containing at least a silver component to the bottom surface of the recess;
Storing the LED chip in the recess, and bonding the LED chip and the bottom surface of the recess with the die bonding agent;
Filling a gap between the recess and the LED chip with a light shielding material having a low transmittance at least in the wavelength region of the light;
A method for manufacturing a light-emitting device including: A method of manufacturing a light emitting device including a substrate and an LED (Light Emitting Diode) chip mounted on the substrate and emitting light from the light emitting layer from an emission surface,
Producing a conductive pattern on the substrate;
Forming a recess having an opening slightly larger than the emitting surface of the LED chip on the surface of the pattern portion; and
Applying a die bond agent containing at least a silver component to the bottom surface of the recess;
Storing the LED chip in the recess, and bonding the LED chip and the bottom surface of the recess with the die bonding agent;
Arranging a light shielding member that shields light at least in the wavelength region of the light so as to protrude from the edge of the opening toward the LED chip;
A method for manufacturing a light-emitting device including: The LED chip includes at least one electrode on the emission surface side,
The method for manufacturing a light emitting device according to claim 13 , wherein the method for manufacturing the light emitting device includes a step of bonding a wire to the electrode.

Images