JP2007227738A - WIRING BOARD FOR LIGHT EMITTING ELEMENT AND LIGHT EMITTING DEVICE - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting element wiring board and a light emitting device excellent in heat dissipation and mounting reliability.
SOLUTION: An insulating base 1 and a protruding portion 8a penetrating through the insulating base 1 and having an end protruding from one main surface of the insulating base 1, and a protruding portion 8b on the side of the protruding portion 8a. And a mounting surface for mounting the light emitting element 21 disposed on one main surface 1a of the insulating base 1 or an end surface of the metal body 8 on the one main surface 1a side of the insulating base 1. 9, and the mounting surface 9 and the protruding portion 8 a are covered and sealed with a sealing resin 31.
[Selection] Figure 1

Description

  The present invention relates to a light emitting element wiring board and a light emitting device for mounting a light emitting element such as a light emitting diode.

  Conventionally, light emitting devices using LEDs have been used for various applications because of their extremely high luminous efficiency and the small amount of heat generated with light emission compared to incandescent bulbs. However, since the amount of emitted light is small compared to incandescent bulbs, fluorescent lamps, etc., it is used not for illumination but as a display light source, and the energization amount is very small at about 30 mA. (For example, refer to Patent Document 1).

  In recent years, with the increase in brightness and whiteness of light-emitting devices using light-emitting elements, light-emitting devices have been frequently used for backlights of mobile phones, large liquid crystal TVs, and the like. However, as the brightness of light emitting elements increases, the heat generated from the light emitting device also increases, and in order to eliminate the decrease in the brightness of the light emitting elements, such heat dissipation that dissipates such heat more quickly than the elements is high. The wiring board for light emitting elements having the above is required (see, for example, Patent Documents 2 and 3).

Due to this expanded use, it is required to increase the brightness of the light-emitting element. Along with this, the heat generated from the light-emitting device is also increasing, and there is a problem that the filler is peeled off from the filling portion due to thermal stress. On the other hand, a structure is employed in which the light emitting element is mounted on the bottom surface of the concave storage portion and the opening end of the storage portion filled with the filler is exposed like an eave to prevent the filler from peeling and dropping ( For example, see Patent Document 4.)
JP 2002-124790 A Japanese Patent Laid-Open No. 11-112025 JP 2003-347600 A JP 2004-111937 A

  However, the method described in Patent Document 4 has a problem in that light is blocked by the eaves provided at the opening end and the light use efficiency is lowered.

  Therefore, the present invention improves the heat dissipating property of the light emitting element wiring substrate, suppresses the decrease in light utilization efficiency, and suppresses the drop of the sealing resin from the light emitting element wiring substrate. An object is to provide an element wiring board and a light emitting device using the light emitting element wiring board.

  The light-emitting element wiring board of the present invention includes an insulating base and a protruding portion that penetrates the insulating base and has an end protruding from one main surface of the insulating base, and a protruding portion on a side of the protruding portion. And a mounting surface for mounting the light-emitting element, disposed on one main surface of the insulating base or an end surface of the one of the main surfaces of the insulating base. The surface and the projection are covered with a sealing resin and sealed.

  In the light-emitting element wiring board according to the present invention, the insulating base is preferably made of ceramics.

  In the light emitting element wiring board of the present invention, the mounting surface is disposed on the end surface of the metal body, and the metal body has a cross-sectional area in a direction parallel to the mounting surface of the light emitting element. The mounting area of the light emitting element mounted on the mounting surface is preferably larger.

  In the light-emitting element wiring board of the present invention, a frame body for accommodating the light-emitting element is formed on one main surface of the insulating base so as to surround the mounting surface, and the height of the frame body Is preferably higher than the height of the protrusion.

  In the light emitting device of the present invention, a light emitting element is mounted on the mounting surface of the light emitting element wiring board described above, and a sealing resin covers the light emitting element, the mounting surface, and the protrusion, and It is characterized by surrounding the overhanging portion.

  The wiring board for a light emitting element of the present invention can improve the thermal conductivity of the wiring board for a light emitting element by providing a metal body so as to penetrate the insulating base, and more quickly generate heat generated from the light emitting element. Since the light can be diffused out of the wiring substrate for the light emitting element, it is possible to prevent the light emitting element from being heated excessively, to prevent a decrease in luminance, or to further increase the luminance. And by providing the protruding part on the side of the protruding part of the metal body, the sealing resin can be physically locked to the wiring board for the light emitting element, so that the sealing resin is prevented from falling off. Can do.

In addition, this metal body is made of a metal plate or metal foil, has substantially no voids, and does not contain ceramic powder or glass components other than metal inside, and is used for a normal wiring board. It cannot be obtained by a method of sintering a paste-like metal conductor. That is, the present invention uses, for example, a dense metal body that is obtained by processing a metal foil or a metal plate and does not substantially contain components other than metal.

  Further, by using a ceramic having a higher thermal conductivity than the resin as the insulating base, it is possible to further increase the luminance of the light emitting element wiring board.

  In addition, by disposing the mounting surface on the metal body and making the cross-sectional area of the metal body larger than the mounting area of the mounted light emitting element, the heat dissipation path becomes larger, so heat generated from the light emitting element can be dissipated more quickly. can do.

  In addition, when a frame body that is higher than the protruding portion is formed on the wiring board for the light emitting element, it is possible to suppress the sealing resin from flowing out when the protruding portion is covered with the sealing resin. Becomes easy. In addition, since the protrusion can be protected by the frame body, the handleability is improved.

  According to the light emitting device of the present invention in which the light emitting element is mounted on the wiring substrate for the light emitting element of the present invention described above, the heat generation from the light emitting element can be quickly discharged outside the device, so that the luminance reduction due to the heat generation is suppressed. In addition, the sealing resin can be firmly locked to the light emitting element wiring substrate.

  The light emitting element wiring board of the present invention has, for example, a flat insulating base 1 and a through hole formed so as to penetrate the front and back surfaces of the insulating base 1 as shown in FIGS. 1 (a) and 1 (b). A connection terminal 3 between the hole 2 and the light emitting element formed on the main surface 1 a of the insulating base 1, an external electrode terminal 5 formed on the other main surface 1 b of the insulating base 1, a connection terminal 3 and an external electrode terminal 5 The insulating base 1 is inserted into the through-hole 7 provided through the insulating base 1 so as to be electrically connected to the through-hole 2 provided through the insulating base 1 and joined to the insulating base 1. It is comprised from the metal body 8 with higher heat conductivity.

  And in order to join the insulation base | substrate 1 and the metal body 8, the joining layer 18 containing at least 1 sort (s) chosen from the group of a metal, resin, and ceramics is formed between both.

  A mounting surface 9 for mounting a light emitting element is formed between one connection terminal 3a and the other connection terminal 3b. The mounting surface 9 is preferably formed on the end surface of the metal body 8 from the viewpoint of improving heat dissipation. In such a form, the light from the light emitting element is not blocked. Since the cross-sectional area of the metal body 8 in the direction parallel to the mounting surface 9 is larger than the mounting area of the light-emitting element mounted on the mounting surface 9, it becomes easier to mount the light-emitting element and the heat dissipation path is also widened. The heat dissipation of the wiring board 11 for light emitting elements is also improved.

  According to the light emitting element wiring substrate 11 of the present invention, one end of the metal body 8 protrudes from the main surface 1a of the insulating base 1 to form the protrusion 8a, and the side of the protrusion 8a. It is important that the overhang 8b is formed. With such a configuration, when the light emitting element is mounted on the light emitting element wiring substrate 11 of the present invention and the light emitting element is sealed with the sealing resin, the sealing resin and the light emitting element wiring substrate 11 In addition, the protruding area 8b of the protrusion 8a can function as a hook, and the sealing resin can be physically and securely locked to the light emitting element wiring substrate 11. The omission of the sealing resin can be suppressed.

  In addition, when the metal body 8 is inserted into the through-hole 2, the overhanging portion 8 b can prevent the metal body 8 from falling off in one direction, and the metal body 8 can be easily positioned. There is also an advantage that the assemblability is remarkably improved.

  Further, as shown in FIG. 1A, when the cross-sectional shape of the protruding portion 8a is an inversely tapered shape, the sealing resin can be locked in a wider portion of the protruding portion 8b. Concentration of excessive stress on the protruding portion 8b or a part of the sealing resin can be suppressed.

  Further, for example, in the wiring board 11 for light emitting element of the present invention, as shown in FIGS. 1A and 1B, a frame 13 for accommodating the light emitting element to be mounted is provided on the mounting surface 9 side. It is desirable to be formed and configured, and it is desirable that the height of the frame 13 is higher than the height of the protrusion of the metal body 8. Thereby, the light from the light emitting element can be guided in a predetermined direction, and the metal body 8 having the protrusions 8a can be protected, and the light emitting element wiring substrate 11 having excellent handleability is obtained.

  According to such a light emitting element wiring substrate 11 of the present invention, the metal body 8 having a thermal conductivity higher than that of the insulating base 1 is disposed through the through hole 2 formed in the insulating base 1. This is very important.

  That is, by providing the metal body 8 having a higher thermal conductivity than the insulating base 1, heat generated from the light emitting element mounted on the light emitting element wiring board of the present invention can be quickly dissipated. It is possible to prevent a decrease in luminance.

  It is important that the metal body 8 is substantially free of voids.

  In other words, by using this metal body 8, in other words, by using the metal body 8 formed of a solid metal, compared to the case of using a composite containing bubbles, ceramic powder, glass or the like inside. As a result, the thermal conductivity of the metal body 8 can be remarkably increased, and the light emitting element wiring substrate 11 is further excellent in heat dissipation.

  Such a metal body 8 can be easily obtained by, for example, punching a metal plate made of Cu having a high thermal conductivity, a low resistance, and a relatively low cost, or a metal foil into a desired shape by a press machine. Can be produced.

  The metal body 8 having a complicated shape can be formed by a technique such as pressing, casting, polishing, powder metallurgy, or the like. Needless to say, the metal body 8 may be manufactured by using other conventionally known processing methods.

  Further, as the material of the metal plate 8, in addition to Cu, a composite material such as Al or Cu-W can be used. In the case of using a composite material such as Cu-W containing two or more kinds of metals, the metal body 8 having desired characteristics can be produced by controlling the metal used and its ratio. Of course, the metal body 8 may be made of an alloy. Moreover, the metal body 8 may be configured by combining a plurality of members.

  Such a metal body 8 can be easily obtained at low cost and can be easily attached to various forms of the insulating base 1, so that various forms of the insulating base can be used according to the performance of the mounted light emitting element. 1 can be used to achieve an optimal combination based on performance and cost.

Next, the insulating base 1 will be described. As the insulating substrate 1 used for the light emitting element wiring substrate 11, for example, a ceramic substrate such as MgO or Al ₂ O ₃ or an organic resin substrate can be preferably used. In particular, when a ceramic substrate is used, the heat conductivity of the insulating substrate is increased, so that the heat dissipation of the light emitting element wiring substrate 11 can be further improved.

  Further, when a ceramic substrate is used as the insulating substrate 1, it has high performance because it is highly rigid, does not change in quality due to light or heat emitted from the light emitting element, and has a relatively large number of materials having high thermal conductivity. The light-emitting element wiring substrate 11 has a long life.

In addition, when a low-temperature fired substrate, so-called glass ceramics, is used as the insulating substrate 1, the thermal conductivity, strength, and rigidity are not limited to ceramics fired in a temperature range of 1050 ° C. or higher such as Al ₂ O _3. Although it is inferior, since the thermal expansion coefficient can be easily controlled, it is possible to easily match the thermal expansion coefficient with the metal body 8. Further, since low resistance Cu, Ag, or the like can be simultaneously fired as the wiring layer, electrical loss and heat generation in portions other than the light emitting element can be suppressed.

  Moreover, when resin is used as the insulating substrate 1, an inexpensive light emitting element wiring substrate 11 is obtained. In order to improve the rigidity, strength, hygroscopicity, and heat resistance of the insulating substrate 1, it is desirable to use a ceramic substrate or a resin substrate containing glass cloth.

  The materials used as these insulating bases 1 will be described in detail below.

For example, the insulating substrate 1 having MgO as the main crystal is, for example, an MgO powder having an average particle diameter of 0.1 to 8 μm and a purity of 99% or more, Y ₂ O ₃ or Yb ₂ O having an average particle diameter of 0.1 to 8 μm. rare earth oxides such as _{3, Al 2 O 3, SiO} 2, CaO, SrO, BaO, and _B 2 O 3, the molded body obtained by adding at least one sintering aid selected from the group consisting of ZrO ₂ 1300 to It is obtained by firing in a temperature range of 1700 ° C.

Alternatively, MgAl ₂ O ₄ containing MgO or MgO · SiO ₂ based composite oxide may be added. The amount of the composition other than MgO, such as a sintering aid, is desirably 30% by mass or less, and more desirably 20% by mass or less in order to obtain a dense body having MgO as the main crystal. Is desirable. In particular, when the addition amount of a composition other than MgO, such as a sintering aid, is 10% by mass or less, most of the obtained insulating substrate 1 can be formed of MgO crystals. These sintering aids are desirably added in an amount of 3% by mass or more, and more preferably 5% by mass or more in order to lower the firing temperature.

  The MgO-based sintered body having MgO as the main crystal phase is such that, for example, the peak of MgO is detected as the main peak by X-ray diffraction, and the volume ratio of MgO crystals is 50% by volume. It is desirable to contain above.

Further, when an Al ₂ O ₃ sintered body having Al ₂ O ₃ as a main crystal phase is used as the insulating base 1, an inexpensive raw material can be used, and an inexpensive light-emitting element wiring substrate 11 is obtained. be able to.

Note that the _Al 2 _{O 3} and _Al 2 _{O 3} quality sintered body composed mainly crystalline phase, for example, by X-ray diffraction, is like the peak of _Al 2 _{O 3} is detected as the main peak, Al ₂ It is desirable to contain 50% or more by volume of O ₃ crystals.

Such an Al ₂ O ₃ sintered body has, for example, an average particle size of 0.1 to 8 μm, preferably 1.0 to 2.0 μm and an Al ₂ O ₃ powder with a purity of 99% or more and an average particle size of 1 Firing a molded body to which at least one kind of sintering aid selected from the group of Mn ₂ O ₃ , SiO ₂ , MgO, SrO, and CaO of 0 to 2.0 μm is added in a temperature range of 1300 to 1500 ° C. Is obtained.

And, for the addition amount of Al ₂ O ₃ other than the compositions, such as sintering aids, in order to obtain a dense body of the Al ₂ O ₃ as a main crystal, preferably 15 wt% or less, more desirably, 10 It is desirable to set it as mass% or less. In particular, when the amount of a composition other than Al ₂ O ₃ such as a sintering aid is set to 15% by mass or less, most of the obtained insulating substrate 1 can be formed of Al ₂ O ₃ crystals. . These sintering aids are desirably added in an amount of 5% by mass or more, and more preferably 7% by mass or more in order to lower the firing temperature. In addition, as the ceramic used for the insulating substrate 1, a sintered body having AlN, Si ₃ N ₄ or the like as a main crystal may be used.

To such a composition containing MgO or Al ₂ O ₃ as a main component, a binder and a solvent are further added to prepare a slurry. For example, a sheet-like molded body is prepared by a doctor blade method, Then, after printing and filling a conductive paste containing at least a metal powder on the surface or through holes provided in the sheet-like molded body, the sheet is laminated and then laminated in an oxidizing atmosphere, a reducing atmosphere, or an inert atmosphere. By firing, the insulating base body 1 in which wiring layers such as the connection terminals 3, the external electrode terminals 5, and the through conductors 7 are formed on the surface or inside can be manufactured. Needless to say, the wiring layer can be formed on the surface of the insulating substrate 1 by a thin film method or by transferring a metal foil onto the surface of the molded body.

  Needless to say, it is necessary to previously form a hole to be the through hole 2 for inserting the metal body 8 in the sheet-like molded body before the firing step.

  Further, even when a low-temperature fired substrate is used as the insulating substrate 1, the insulating substrate 1 provided with the through-holes 2 and the wiring layer is basically manufactured in the same manner, although the materials and the firing temperature are different. Can do.

  Further, when a resin is used as the insulating substrate 1, it is desirable to use a glass-epoxy substrate used for a conventionally known printed wiring board or the like. On the glass-epoxy substrate, the connection terminal 3, the external electrode terminal 5, and the through conductor 7 are formed by a normal method for manufacturing a printed wiring board, and further, a through hole for forming the metal body 8 is drilled, laser Etc.

  Next, the metal body 8 is prepared for the various insulating bases 1 provided with the through holes 2 described above, the metal body 8 is inserted into the through holes 2, and the insulating base 1 and the metal body are bonded by the bonding layer. 8 can be joined to obtain the wiring substrate 11 for a light emitting element.

  As the bonding layer 18 used here, an adhesive made of metal, ceramics, resin, or a composite is suitably used.

  When a metal is used for the bonding layer 18, the process can be simplified by using a low melting point metal such as solder. Examples of the solder used include conventionally known tin 60 to 10% -lead 40 to 90% and lead-free solder containing no lead.

  When solder is used, the insulating substrate 1 and the metal body 8 can be joined by processing in a reflow furnace in a nitrogen atmosphere under conditions of 230 ° C. × 10 seconds.

  In addition to solder, an active metal can be used to join the insulating substrate 1 and the metal body 8 by a so-called active metal method.

  When a metal is used as the bonding layer 18, it is necessary to form a metal layer on the inner wall of the through hole 2 in order to improve wettability with the bonding layer 18.

  Further, when a resin is used as the bonding layer 18, it is desirable to use a generally used epoxy resin-based bonding agent.

  And according to the curing temperature of each bonding agent, for example, the bonding agent is cured under conditions of 80 to 150 ° C. and 20 to 40 minutes, and the insulating base 1 and the metal body 8 are bonded via the bonding layer 18. be able to.

  Bonding using this resin is excellent in that it is inexpensive and easy. In particular, when combined with the insulating base 1 made of resin, the bonding strength becomes high and processing at a relatively low temperature is possible, so there is almost no damage to the insulating base 1 and there is no crack at the interface. A highly reliable wiring board 11 for a light emitting element can be manufactured.

  Moreover, as a case where ceramics are used as the bonding layer 18, for example, a glass having a low melting point can be exemplified. By using such a low-melting glass, bonding at a relatively low temperature (600 ° C. or less) is possible, and the stress generated by the bonding can be reduced.

  Needless to say, the bonding layer 18 may be a composite of metal, ceramics, and resin. For example, the thermal expansion coefficient of the bonding layer can be controlled by mixing metal powder, ceramic powder, and resin, and bonding according to the characteristics of the insulating substrate 1 can be performed.

  By forming the conductor and metal body 8 used in the wiring circuit formed on the light emitting element wiring substrate 11 as a main component of at least one of W, Mo, Cu, Ag, and Al, the electrical characteristics, An inexpensive light-emitting element wiring substrate 11 having excellent heat dissipation can be obtained.

  Further, by applying Al plating or Ag plating to the surfaces of the connection terminal 3 and the metal body 8, the resistance to corrosion is improved, the reliability of the wiring board 11 for the light emitting element is improved, and the connection terminal 3 and the metal body are improved. The reflectance of 8 can be improved.

  It is desirable to provide the frame 13 on the main surface on the mounting surface 9 side of the light emitting element wiring substrate 11. For example, when using the insulating base 1 made of ceramics, the frame 13 is made of ceramics. By forming, the insulating base 1 and the frame 13 can be fired at the same time, and the process is simplified. Therefore, the inexpensive light-emitting element wiring substrate 11 can be easily manufactured.

  Further, since ceramics are excellent in heat resistance and moisture resistance, a wiring board for a light emitting device having excellent durability even when used for a long period of time or under adverse conditions by using a ceramic frame 13. 11

  In addition, by forming the frame body 13 from a metal that is inexpensive and excellent in workability, even the frame body 13 having a complicated shape can be easily manufactured at low cost, and an inexpensive wiring board for a light-emitting element. 11 can be supplied. This metal frame 13 can be suitably formed by Al, Fe-Ni-Co alloy, etc., for example. Further, a plating layer (not shown) made of Ni, Au, Ag, Al or the like may be formed on the inner wall surface 13a of the frame 13 in order to improve the reflectance.

  When the frame body 13 is formed of a metal in this way, a metal layer 17 is previously formed on the main surface 1a of the insulating base 1, and the metal layer 17 and the frame body 13 are, for example, eutectic Ag. -Brazing via a brazing material (not shown) made of Cu brazing material or the like, or joining by soldering can be performed.

  Needless to say, a resin-based adhesive may be used, and the same material as the resin-based bonding layer 18 can be used.

  Then, for example, as shown in FIGS. 2 (a) and 2 (b), an LED chip 21 or the like is mounted as the light emitting element 21 on the wiring board 11 for the light emitting element of the present invention described above, and the bonding wire 23 By electrically connecting the light-emitting element 21 and the connection terminal 3 and supplying power to the light-emitting element 21, the light-emitting element 21 can function, and heat generated from the light-emitting element 21 can be quickly emitted from the metal body 8. Therefore, a heat radiating member such as a heat sink is not necessary, and it is possible to contribute to downsizing of an electric device to be mounted, and at low cost, the light emitting device 25 excellent in reliability in which a sealing resin is firmly fixed can be obtained. In addition, by providing a heat sink, it is needless to say that heat dissipation is further improved, and for example, provision of a cooling device such as a heat sink is not excluded.

  Further, an LED chip 21 or the like is mounted on the mounting surface 9 formed on the light emitting element wiring substrate 11 as, for example, the light emitting element 21, and the LED chip 21 and the connection terminal 3 are electrically connected by a bonding wire 23. By supplying power, the light emitted from the light emitting element 21 can be reflected by the insulating base 1 and the frame 13 and guided in a predetermined direction, so that the highly efficient light emitting device 25 is obtained. In addition, since the metal body 8 has a high thermal conductivity, heat generated from the light emitting element 21 can be quickly released, and a reduction in luminance due to heat generation can be suppressed.

  In the light emitting device 25 using the light emitting element wiring substrate 11 of the present invention, the sealing resin 31 is formed so as to cover the light emitting element 21, the mounting surface 9, and the protruding portion 8 a and surround the protruding portion 8 b. Thus, they can be sealed and the sealing resin 31 can be firmly fixed to the wiring board 11 for light emitting elements. In particular, when the mounting surface 9 is formed on the end surface of the protruding portion 8a, the light from the light emitting element 21 is not hindered by the protruding portion 8a, so that the light extraction efficiency is improved.

  2A and 2B, in the light emitting device 25 in which the frame 13 is mounted on the main surface 1a of the light emitting element wiring substrate 11 on the side where the light emitting element 21 is mounted, the frame 13 By storing the light emitting element 21 inside the light emitting element 21, the light emitting element 21 can be easily protected.

  Moreover, although the light emitting element 21 is covered with the sealing resin 31, the sealing resin 31 and the lid may be used in combination. In addition, as a cover body, it is desirable to use translucent materials, such as glass.

  In addition, when mounting the light emitting element 21, you may add the fluorescent substance (not shown) for wavelength-converting the light which the light emitting element 21 radiates | emits to this sealing resin 31 as needed.

  Further, the sealing portion 33 in the present invention means a region covered with the sealing resin 31, and for example, the inner region of the frame 13 corresponds to the sealing portion 33 in FIGS.

  In the example described above, the example in which the through conductor 7 is provided has been described. However, the through conductor 7 may not be provided, and the insulating base 1 may be laminated in multiple layers. Of course it is good.

  Moreover, in the example demonstrated above, although the form which provided the frame 13 was demonstrated, it cannot be overemphasized that the form which does not comprise the frame 13 may be sufficient.

Using MgO powder with a purity of 99% or more and an average particle diameter of 1 μm, and Y ₂ O ₃ powder with a purity of 99% or more and an average particle diameter of 1 μm as a raw material powder for an insulating substrate of a wiring board for a light emitting device, 95% by mass of MgO powder The raw material powder was mixed at a ratio of 5% by mass of Y ₂ O ₃ , an acrylic binder as a molding organic resin (binder), and toluene as a solvent were mixed to prepare a slurry.

  Thereafter, a ceramic green sheet was prepared by a doctor blade method.

Further, using W and Cu powder having an average particle diameter of ₂ μm and Al ₂ O ₃ having an average particle diameter of 1.0 μm, the metal powder and the acrylic system at a ratio of W 50 mass%, Cu 50 mass%, and Al ₂ O ₃ 5 mass% A binder and acetone were mixed as a solvent to prepare a conductor paste.

  The ceramic green sheet is punched to form a via hole having a diameter of 100 μm for forming a through conductor, and the via hole is filled with a conductive paste by a screen printing method, and a wiring pattern is formed. Was printed and applied. In addition, a through hole for inserting a metal body was formed together with a via hole during punching.

  The green sheets thus produced were combined, aligned, laminated and pressure-bonded, and a laminate having dimensions after firing of 10 mm × 10 mm × 0.6 mm in thickness was produced.

  In addition, this laminated body produced three types, the thing which does not provide a frame, the thing which provides a ceramic frame, and the thing which provides a metal frame.

  For the ceramic frame body, the mounting surface side on which the light emitting element of the multilayer body is mounted has an outer dimension of 10 mm × 10 mm × 2 mm, the inner diameter on the side in contact with the multilayer body is 4 mm, and reversely A frame made of the same material as that of the insulating substrate having a tapered through hole with an inner diameter of 8 mm on the side was formed. In addition, the molded object used as this frame was formed as an integral body by thermocompression bonding with the laminate.

  Moreover, about what provides a metal frame, the metal paste was screen-printed in the part which contact | connects the frame of the mounting surface side of a laminated body, and the metal layer was formed.

  And after degreasing the laminated body integrated with the molded body to be a frame body at 900 ° C. in a nitrogen-hydrogen mixed atmosphere having a dew point of + 25 ° C., subsequently, a maximum temperature of 1400 ° C. in a nitrogen-hydrogen mixed atmosphere having a dew point of + 25 ° C. And baked for 2 hours.

Thereafter, Ni and Au plating were sequentially applied to the surfaces of the connection terminal and the external electrode terminal. Since the chemical resistance of MgO is lower than that of Al ₂ O ₃ or the like, the concentration of the plating treatment solution is reduced and the plating treatment temperature is lowered so that the surface state of the wiring board for light emitting elements does not deteriorate. Then, the plating treatment of the wiring board for light emitting device of the present invention was performed.

Next, for a sample provided with a metal frame, an Al metal frame having a thermal expansion coefficient of 23 × 10 ⁻⁶ / ° C. and a thermal conductivity of 238 W / m · K is used to form a frame using solder. Was bonded to an insulating substrate.

  In addition, the metal body is provided with a protruding portion at the center of the side surface as shown in FIG. Cutting was performed to obtain a new shape. Note that the dimensions of the two types of metal bodies are as shown in FIG. 3, and both of the metal bodies were substantially cylindrical.

  The through hole was formed so that a gap of 50 μm was formed between the metal body and the through hole when the metal body was inserted into the inner wall of the through hole. In addition, although the composition of the metal body is shown in Table 1, a solid metal body having a purity of 99% or more is used for those using a single metal element. Moreover, about the metal body described as Cu-W, the composition of Cu 20 mass% and W mass 80% was used.

  Next, an epoxy resin adhesive was applied to the surface of the metal body with a dispenser, and the metal body coated with the epoxy resin adhesive was inserted into the through hole of the insulating substrate. Thereafter, the adhesive was cured at 120 ° C. for 30 minutes to bond the metal body and the insulating substrate to obtain a wiring board for a light emitting element.

Further, an epoxy resin adhesive is applied to the mounting surface of the wiring board for these light emitting elements using a dispenser, and the light emitting element with an output of 1.5 W whose outer dimensions are 0.6 mm × 0.6 mm × 0.1 mm. The LED chip is mounted, the LED chip and the connection terminal are connected with a bonding wire, and the LED chip and the connection terminal are covered with a sealing resin made of an epoxy resin having a thermal expansion coefficient of 40 × 10 ⁻⁶ / ° C. A light emitting device was obtained.

  Using the obtained light emitting device, a temperature cycle test of −55 ° C. to 125 ° C. was performed 1000 cycles, and after the test, the peeling state of the bonding interface between the sealing resin and the insulating substrate was confirmed.

  Further, a current of 0.4 A was passed through the light emitting device, and the total radiant flux was measured after 1 hour.

In addition, as a comparative example, in place of the step of inserting and joining the metal body into the through-hole, the through-hole for inserting the metal body contains W50, Cu, and Al ₂ O ₃ previously produced. The step of filling the conductor paste and the step of simultaneously firing the laminate and the conductor paste filled in the through holes were performed, and the same test as in the example was performed. This conductor paste contains voids after simultaneous firing, and contains ceramic powder and glass components other than metal inside. That is, it is not dense obtained by a method outside the scope of the present invention, but substantially contains components other than metals.

  In addition, the sample produced as a comparative example is not provided with a protrusion or an overhang.

Al ₂ O ₃ powder having a purity of 99% or more and an average particle size of 1.0 μm as a raw material powder, Mn ₂ O ₃ powder having a purity of 99% or more and an average particle size of 1.3 μm, a purity of 99% or more, an average particle size of 1. using SiO ₂ powder 0 .mu.m, _Al 2 _{O 3} powder 90 wt%, _Mn 2 _{O 3} powder 5% by weight, mixing the raw material powder at a ratio of SiO ₂ powder 5% by weight, as molding organic resin (binder) An acrylic binder and toluene were mixed as a solvent to prepare a slurry. Thereafter, a ceramic green sheet was prepared by a doctor blade method.

  The conductor paste was prepared by using the same raw material as that used when MgO was the main component and adjusting the same process at the same rate.

  The ceramic green sheet is punched to form a via hole having a diameter of 100 μm for forming a through conductor, and the via hole is filled with a conductive paste by a screen printing method, and a wiring pattern is formed. Was printed and applied. In addition, a through hole for inserting a metal body was formed together with a via hole during punching.

  The green sheets thus produced were combined, aligned, laminated and pressure-bonded, and a laminate having dimensions after firing of 10 mm × 10 mm × 0.6 mm in thickness was produced.

  And after performing degreasing | defatting at 900 degreeC in nitrogen-hydrogen mixed atmosphere with dew point +25 degreeC, it continued and baked by hold | maintaining at the highest temperature of 1300 degreeC for 2 hours in nitrogen-hydrogen mixed atmosphere with dew point +25 degreeC.

  Thereafter, Ni and Au plating were sequentially applied to the surfaces of the connection terminal and the external electrode terminal.

In Example 2, a metal frame was used. As the material of the frame used, an Al metal frame having a thermal expansion coefficient of 23 × 10 ⁻⁶ / ° C. and a thermal conductivity of 238 W / m · K was used. In addition, for the metal frame, a solder paste is used after forming a metal layer on the portion where the frame on the mounting surface side of the insulating substrate is mounted using a conductive paste that forms connection terminals and external electrode terminals. The frame body was bonded to an insulating substrate.

Further, the metal body having the form shown in FIG. 3 was used as in the case of using MgO as a main component. Then, in the same process as in Example 1, the insulating substrate and the metal body were joined with an epoxy resin adhesive to obtain a wiring board for a light emitting element. The thermal expansion coefficient of the insulating substrate was 7.5 × 10 ⁻⁶ .

An epoxy resin as a bonding agent is applied to these light emitting element wiring boards using a dispenser, and an LED chip which is a light emitting element with an outer dimension of 0.6 mm × 0.6 mm × 0.1 mm and an output of 1.5 W is mounted on the surface. The LED chip and the connection terminal are connected with a bonding wire, and the LED chip and the connection terminal are covered with a sealing resin made of an epoxy resin having a thermal expansion coefficient of 40 × 10 ⁻⁶ / ° C. Got.

  The obtained light emitting device was subjected to a temperature cycle test of −55 ° C. to 125 ° C. for 1000 cycles, and after the test, the peeling state of the bonding interface between the sealing resin and the insulating substrate was confirmed.

  Further, a current of 0.4 A was passed through the light emitting device, and the total radiant flux was measured after 1 hour.

Table 1 shows the characteristics and test results of the wiring board for a light-emitting element manufactured through the above steps.

  As shown in Table 1, Sample No. which is not dense and uses a metal body substantially containing a component other than metal and has no protrusions and is outside the scope of the present invention. 1, sample No. 1 of the present invention using a dense metal body substantially free of components other than metal. It can be seen that the heat dissipation and light characteristics of the light emitting device are inferior to those of 2. Moreover, peeling of the sealing resin was also confirmed.

  On the other hand, Sample No. which is a wiring board for a light emitting element of the present invention. Nos. 2 to 26 are affected by the thermal conductivity of the insulating substrate, but by using a dense metal body that eliminates the factors that hinder thermal conduction such as voids and ceramic powder, excellent heat dissipation and optical characteristics can be obtained. The light-emitting device had, and peeling of the sealing resin was not confirmed.

FIG. 1 is a cross-sectional view of a light-emitting element wiring board according to the present invention. FIG. 2 is a cross-sectional view of the light emitting device of the present invention. FIG. 3 is a schematic diagram showing the outer dimensions of the through metal body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Insulation base | substrate 2 ... Through-hole 3 ... Connection terminal 5 ... External electrode terminal 7 ... Through-conductor 8 ... Metal body 9 ... Mounting surface 11 ... Wiring for light emitting elements Substrate 13 ··· Frame 13a ··· Inner wall surface 17 of frame ··· Metal layer 18 ··· Bonding layer 21 ··· Light emitting element 23 ··· Wire bond 25 · · · Light emitting device 29 · · · Bonding agent 31 ... Sealing resin 33 ... Sealing part

Claims (5)

An insulating base, a metal body penetrating through the insulating base and having an end projecting from one main surface of the insulating base, and a projecting portion on a side of the projecting base, and the insulating base And a mounting surface on which the light emitting element is mounted, which is disposed on one main surface of the insulating body of the metal body, and the mounting surface and the protruding portion are encapsulating resin. A wiring board for a light emitting element, wherein the wiring board is covered with and sealed. The light-emitting element wiring board according to claim 1, wherein the insulating base is made of ceramics. The mounting surface is disposed on the end surface of the metal body, and a cross-sectional area of the metal body in a direction parallel to the mounting surface of the light emitting element is mounted on the mounting surface of the light emitting element. The wiring board for a light emitting element according to claim 1, wherein the wiring board is larger than an area. A frame for accommodating the light emitting element is formed on one main surface of the insulating base so as to surround the mounting surface, and the height of the frame is higher than the height of the protrusion. The wiring board for light emitting elements according to any one of claims 1 to 3. A light emitting element is mounted on the mounting surface of the wiring board for a light emitting element according to claim 1, and a sealing resin covers the light emitting element, the mounting surface, and the protrusion, and the A light emitting device characterized by surrounding an overhanging portion.

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