JP2828142B2 - LED lamp and method of forming the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED lamp using a light emitting element, and more particularly, to an LED lamp having a cup on which a light emitting element is mounted on a lead terminal and having high directional characteristics and high reliability.
It relates to an ED lamp.

[0002]

2. Description of the Related Art LED lamps are small, efficient and emit bright colors. In addition, since the semiconductor element is used, the ball is not broken due to strong ON / OFF repetition. Further, due to their excellent initial drive characteristics, they have begun to be used in various fields such as optical sensors, write / read light sources, backlight light sources, and various display devices.

A specific example of such an LED lamp will be described. The LED lamp is mounted on the mounting lead 6 as shown in FIG.
The light-emitting element 601 is arranged on a cup formed at the tip of 04. One electrode of the light emitting element is electrically connected to the mount lead. The other electrode of the light emitting element has an inner lead 60 using a conductive wire 603 or the like.
5 is electrically connected. Further, a mold member 602 having a lens function to protect the light emitting element from external force from an external environment, moisture, dust, or the like, or to obtain desired directional characteristics may be provided. The cup in which the light emitting element is provided can have a function as a reflector. Such a cup can be easily formed by pressing the tip of the lead terminal.

[0004]

As an LED lamp having a mold member, there is an LED lamp having an elliptical shape in plan view from the light emission observation surface side. In such an LED lamp, the directivity can be changed as desired by, for example, expanding only one of the directional characteristics by a mold member, but the central luminous intensity is reduced due to a lens effect. Therefore, it is conceivable to increase the shape of the cup to increase the central luminous intensity. Similarly, a light emitting element (hereinafter, L
Also called an ED chip. In some cases, the cup may be enlarged even in a mount lead in which a plurality of) are arranged. Specifically, in some cases, it is necessary to uniformly form a large cup having a lead terminal having a thickness of about 0.5 mm and a bottom surface having an elliptical shape or the like and having a thickness of about 2 mm ² .
Since the cup is formed using the lead terminal, the thickness of the lead terminal is increased to increase the size. Alternatively, it is necessary to increase the depth during press working.

[0005] However, the thickness of the lead terminals cannot be made too large due to the mounting space of the LED lamps and the reduction in the yield during punching scrap. In addition, there is a limit in increasing the depth at the time of press working in consideration of the connectivity and directional characteristics of the wire connecting the light emitting element and the inner lead. In any case, it is not easy to form a large-sized cup into a uniform shape. When a cup having a uniform shape is not formed, an LED lamp having a distorted directional characteristic may be obtained depending on the shape of the cup.

Accordingly, an object of the present invention is to provide an LED lamp in which the shape of a cup in which an LED chip is arranged can be formed into a desired shape that can be enlarged, and a desired directional characteristic can be obtained with a high yield. .

[0007]

SUMMARY OF THE INVENTION The present invention provides an LED having a light emitting element disposed on a cup of a mounting lead, and an inner lead electrically connected to the light emitting element.
A lamp, as viewed from the emission observation side,
The above problem can be solved by using an LED lamp having a recess at the tip of the lead between the cup and the tip. Thus, by providing a concave portion at the tip of the mount lead, it is possible to prevent distortion of the cup shape and increase the thickness of the cup shape. In addition, since the tip of the mount lead can be smoothed, a large-sized cup can be formed uniformly.

According to a second aspect of the present invention, a conductive wire connected to a light emitting element is wire-bonded to a tip portion of a mount lead. This makes it possible to provide an LED lamp that can obtain desired light emission characteristics with high reliability.

An LED lamp according to a third aspect of the present invention is an LED lamp having a mold member covering at least a light emitting element. Thus, desired light emitting characteristics can be obtained while protecting the light emitting element.

In the LED lamp according to a fourth aspect of the present invention, the mold member has an elliptical shape in plan view and has an ellipsoidal surface, and a direction parallel to a major axis of the ellipse shape in plan view is larger than a direction parallel to the vertical direction. It has a long cup. This makes it possible to form an LED lamp having a wide directivity angle in the major axis direction and a narrow directivity angle in the short axis direction in a plan view elliptical shape with high yield.

A method according to a fifth aspect of the present invention relates to a method for forming an LED lamp having a cup in which a light emitting element is disposed at the tip of a mount lead. In particular, an LED having a step of pressing a tip of a metal piece serving as a mount lead to form a recess having a buffer function and a step of pressing a tip of one metal piece through the recess to form a cup This is a method for forming a lamp. This makes it possible to form a highly reliable LED lamp having a desired large-size cup with good mass productivity.

According to a sixth aspect of the present invention, after the step of forming a recess having a buffer function, the tip of the other metal piece is pressed through the recess to form a tip portion for wire bonding. It has a process. As a result, even when wire bonding is performed to the mount lead, a highly reliable LED lamp having desired directional characteristics and high reliability can be formed with a high yield.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The inventor of the present invention
In an LED lamp using a large-sized cup or a flattened tip portion of a mount lead, it was found that the uniformity of the directional characteristics greatly changed depending on the specific shape of the mount lead, and based on this, the present invention was accomplished. Was.

That is, the shape of the cup in which the light emitting elements are arranged has a great influence on the directional characteristics of the LED lamp. In particular, if a relatively large cup is formed in accordance with the case where a plurality of light emitting elements are arranged or the shape of the mold member, the directional characteristics are likely to be uneven. Such variation in the directivity tends to increase as the cup size increases. The thickness of the cup becomes thinner as the size of the cup is increased due to compression or the like utilizing the metal of the lead terminal. Also, the extra metal part pressed to form the cup has to move somewhere. Extra metal is not always used in larger cups. Therefore, it is considered that distortion is easily generated on the side surface of the cup, which affects the directivity. Also, depending on the LED lamp, a conductive wire may be electrically connected using the tip of the mount lead. It is desirable that such a connection end face be pressed to improve the adhesion of the conductive wire. However, if the connection portion of the conductive wire is pressed and simply flattened, the cup may be distorted as described above. Therefore, the directional characteristics may be adversely affected as described above.

The present invention can absorb the distortion of the cup during the formation of the mount lead. In addition, it is possible to earn metal parts used for forming the cup. As a result, it is possible to form an LED lamp having desired directional characteristics with good yield by uniformly forming a cup with a small distortion as the size increases.

FIG. 1 is a schematic sectional view of an LED lamp according to the present invention. FIG. 2 is a schematic plan view of the LED lamp of the present invention viewed from the light emission observation surface side. The lead terminals are
It uses iron and is silver-plated after the cup is formed.
One of the lead terminals is a mount lead 104 provided with a cup, and a recess 101 having a buffer function for increasing the thickness of the cup and preventing distortion generated during press working is provided near the cup 201. Is provided. The shape of the cup 201 viewed from the emission observation surface side is
It has a large elliptical shape or track shape that is long in the direction perpendicular to the direction between the lead terminals 104 and 105. LED chip 20 using nitride compound semiconductor for light emitting layer on cup
2 is die-bonded with an epoxy resin. The electrodes of the LED chip are wire-bonded to the inner leads 105 and the tip portions 203 on the mount leads 104 having high smoothness using gold wires. An elliptical mold member 102 is formed as a translucent epoxy resin having a lens effect so as to seal the tip of the lead terminal. The formed LED lamp has a cup shape in which the direction parallel to the major axis direction of the ellipse of the mold member is longer than the vertical direction when viewed from the light emission observation surface side. By energizing the LED lamp having such a configuration, an LED lamp with stable directional characteristics and high yield can be obtained. Less than,
The configuration of the present invention will be described in detail.

(Lead Terminals 104 and 105) The lead terminal of the present invention is an inner lead electrically connected to the mount lead 104 on which the light emitting element 202 is mounted and the light emitting element via an electrical connecting member such as a conductive wire.・ Lead 10
5. A plurality of inner leads 105 can be provided as desired in accordance with the number of light emitting elements 202 and the number of electrodes. A cup 201 on which a light emitting element 202 is mounted on a mount lead 104 and which has a smooth surface with high reflectivity so as to obtain desired light emitting characteristics.
Is preferably provided.

The lead terminals can be formed by pressing a metal plate into a desired shape. The punched lead terminal has a shape in which a plurality of lead terminals are connected by a tie bar 302 as shown in FIG. The concave portion (concave portion) 301 can be formed by partially applying pressure as shown by the arrow in FIG. Due to the formation of the concave portion, an extra metal portion constituting the mount lead is partially moved. Some of the mounting leads are partially thickened due to the moved metal parts. In the present invention, the cup can be formed larger and more uniformly by using the thickened portion.

Further, a conductive wire for electrically connecting to the light emitting element 202 may be connected to the tip portion 203 of the mount lead opposite to the cup 201 via the recess 101 as viewed from the light emission observation surface side. it can. That is, for a nitride-based compound semiconductor formed on an insulating substrate such as sapphire, positive and negative electrodes are taken out from one surface side (semiconductor side). Therefore, not only the electrical connection with the inner lead 105 but also the mounting lead 104 and the L
The electrical connection with the ED chip 202 is also made by the conductive wire 10.
3 may be used.

In order to connect the conductive wire 103 on the surface inside the cup, it is difficult to obtain a uniform reflection due to a ball or the conductive wire itself generated at the time of connection. Therefore, by using the distal end portion 203 of the mount lead as an electrical connection portion, it is possible to relatively easily adhere to each other without distorting the directional characteristics. The surface of the tip of such a mounting lead needs to be flattened for connection of a conductive wire. Flattening can be performed relatively easily by pressing the tip portion 403 of the mount lead as shown in FIG. In the present invention, the concave portion does not adversely affect the cup formation even in the press working of such a tip portion. That is, by pressing and flattening the tip portion of the mount lead, even if an extra metal portion moves, the concave portion has a buffer function, so that the shape of the cup is not adversely affected. Similarly, if the tip portion of the smooth mount lead is formed first, the recess has a buffer function even if an extra metal portion is moved by forming a large cup, so that the recess portion has a buffer function. Does not adversely affect smoothness.

Further, by pressing the tip portion of the mount lead, the surface area of the tip portion to be wire-bonded with the extra moved metal portion can be increased, and the reliability in wire bonding can be improved.
In addition, by making the tip portion the highest on the mount lead, the reliability of wire bonding can be improved. Such a concave portion can have various shapes and depths such as a V-shape, a U-shape, and a semicircle as long as the shape of the cup and the tip of the mount lead are not adversely affected.

In the present invention, the tip portion of the mount lead is a part constituting the outermost surface of the mount lead when viewed from the light emission observation surface side. In the case where a conductive wire is connected to the tip portion, There is a desired area. The specific electric resistance of the lead terminal is 300 μΩ.
Cm or less, more preferably 3 μΩcm
It is as follows. Furthermore, when a plurality of light emitting elements are stacked on the cup of the mount lead, good heat conductivity is required because the amount of heat generated from the light emitting elements increases. Specifically, 0.01 cal / (s) (cm ² ) (° C./c
m) or more, more preferably 0.5 cal /
(S) (cm ² ) (° C./cm) or more. Specific materials for such lead terminals include iron, copper, iron-containing copper,
Preferred is tin-containing copper. In addition, Ag, Au, Al, Cu
May be formed by plating or the like.

The size of the cup is large enough to mount each LED chip with a device such as die bonding, and various types are used in accordance with the light condensing rate of the mold member. In the present invention, since a large and uniform cup can be easily obtained, various cup shapes such as a perfect circle, a track, an ellipse, a triangle, and a rectangle can be obtained when viewed from the light emission observation surface side. In particular, when a plurality of light emitting elements are arranged, a track shape, an elliptical shape, a rectangular shape, or the like is preferable. The edges of the cup need not necessarily be formed on the same plane. Further, the side wall inside the cup does not need to be formed at the same angle with respect to the bottom surface on which the light emitting elements are arranged. That is, when the shape of the mold member is an ellipse or the like, the edge of the cup in the direction parallel to the major axis of the ellipse in the direction in which the directional characteristics spread (narrowed) due to the mold shape are further expanded (narrowed) is set lower than the others. Alternatively, by reducing the angle of the side wall that is parallel to the major axis of the ellipse, the directional characteristics can be broadened.

The connection between the light emitting element and the cup can be made by a thermosetting resin or a photocurable resin. Specifically, a resin that is die-bonded with an epoxy resin, a silicone resin, or the like can be given. In addition, a conductive paste or a metal bump containing a conductive member such as Ag, carbon, ITO, or SnO ₂ can be used for bonding the light emitting element to the cup and electrically connecting the cup.

(Light-emitting elements 106 and 202) Light-emitting element 10
6, 202, GaN on the substrate by liquid phase epitaxy, metalorganic vapor phase epitaxy (MOCVD), halide vapor phase epitaxy (HDVPE), molecular beam vapor phase epitaxy (MBE), etc.
InN, AlN, ZnS, ZnSe, SiC, GaP,
GaAlAs, InGaN, GaAlN, AlInGa
A light-emitting element in which a semiconductor such as P or AlInGaN is formed as a light-emitting layer is preferably used.

The semiconductor structure includes MIS junction, PI
Examples include a homostructure having an N junction or a pn junction, a heterostructure, or a double heterostructure. The emission wavelength can be variously selected from ultraviolet to infrared depending on the material of the light emitting layer and the degree of mixed crystal thereof. Further, in order to have a quantum effect, a single quantum well structure or a well layer and a barrier layer having a larger band gap than the well layer are formed by a well + barrier + ... + barrier +
A multiple quantum well structure formed as a well or vice versa may be used. Thereby, the light emitting element 202 having a high light emission output
It can also be. Such a light emitting element 202 can be variously selected depending on the use or the like. A light-emitting element that emits light with high luminance is more preferable because the effects of the present invention are remarkably exhibited. As a semiconductor material capable of emitting light of high luminance, a nitride-based compound semiconductor (In
_x Ga _y Al _{1-x over} y N, 0 ≦ x, 0 ≦ y, 0 ≦ x + y ≦
It is preferable to use 1). In the case of a red-based semiconductor, a gallium-aluminum-arsenic-based semiconductor or an aluminum-indium-gallium-phosphorus-based semiconductor is preferably used. A specific example of a nitride-based compound semiconductor will be described as such a light-emitting element 202.

Sapphire, spinel, SiC, Si, ZnO
And a material such as gallium nitride single crystal can be suitably used. A sapphire substrate is preferably used to form a gallium nitride-based semiconductor with good crystallinity, and a buffer layer is preferably formed to correct lattice mismatch with the sapphire substrate. For the buffer layer, aluminum nitride, gallium nitride, or the like formed at a low temperature is preferably used.

As an example of a light emitting device having a pn junction using a nitride-based compound semiconductor, a first contact layer formed of n-type gallium nitride on a sapphire substrate with a buffer layer interposed therebetween has a quantum effect. A structure in which an active layer of indium gallium nitride formed of a thin film, a cladding layer formed of p-type aluminum gallium nitride, and a second contact layer formed of p-type gallium nitride may be sequentially stacked.

It should be noted that the nitride-based compound semiconductor shows n-type conductivity without being doped with impurities. When a desired n-type gallium nitride semiconductor is formed, for example, to improve luminous efficiency, Si, Ge, Se, T
It is preferable to appropriately introduce e, C, and the like. On the other hand, in the case of forming a p-type gallium nitride semiconductor, doping is performed with a p-type dopant such as Zn, Mg, Be, Ca, Sr, and Ba. It is difficult to reduce the resistance of the gallium nitride-based compound semiconductor simply by doping it with a p-type dopant. Therefore, it is preferable to reduce the resistance by introducing a p-type dopant and then annealing by heating in a furnace or irradiating plasma.

In the case of the light emitting element 202 using an insulating substrate, a p-type semiconductor and an n-type are used to remove a part of the insulating substrate or to obtain p-type and n-type electrode surfaces from the semiconductor surface side. Each of them can be formed by etching the exposed surface of the semiconductor. Each electrode having a desired shape is formed on each semiconductor layer by using a sputtering method, a vacuum evaporation method, or the like.

The semiconductor wafer or the like on which the electrodes are formed is directly full-cut by a dicing saw in which a blade having a diamond cutting edge is rotated, or is cut into a groove having a width wider than the cutting edge width (half cut). Cracks the semiconductor wafer. Alternatively, a very thin scribe line (meridian) is drawn on the semiconductor wafer, for example, in a checkerboard pattern by a scriber in which a diamond needle at the tip reciprocates linearly, and then the wafer is cut by an external force and cut into chips from the semiconductor wafer. Thus, an LED chip which is a semiconductor light emitting element can be formed.

The light emitting element 202 has RG on one cup.
B uses one light emitting element capable of emitting light, and
A D lamp may be configured, or a plurality of D lamps may be used to obtain a desired wavelength. For example, one blue, two green, and one red can be provided on one cup. Further, the emission wavelength is not necessarily limited to the blue, green, and red colors, but may be one in which the band gap of the semiconductor is adjusted so that yellow or the like can be emitted as desired. As a specific example, a light-emitting diode that emits white light using blue and yellow light-emitting elements can be used. For use as a full-color LED lamp, it is preferable that the emission wavelength of red is 600 nm to 700 nm, the emission of green is 495 nm to 565 nm, and the emission wavelength of blue is 430 nm to 490 nm.

(Conductive Wire 103) As the conductive wire 103 serving as an electrical connection member, one having good ohmic properties, mechanical connectivity, electrical conductivity, and thermal conductivity between the electrode of the light emitting element and the lead terminal. Desired. The thermal conductivity is preferably 0.01 cal / (s) (cm ² ) (° C./cm) or more, more preferably 0.5 cal / (s) (c
m ² ) (° C./cm) or more. Specifically, gold, copper,
Preferable examples include a conductive wire using platinum, aluminum, or the like, and an alloy thereof. An aluminum wire or a gold wire is more preferable in consideration of workability.

(Mold member 102) Mold member 10
2 is preferably provided to protect the light emitting element 106, the conductive wire 103, and the like from the outside. Further, the shape of the mold member 102 can be variously selected as desired. The present invention has an effect that the size of the cup can be easily selected to suit the shape of the mold member 102 because a large-sized cup can be easily formed. The shape of the mold member 102 can be variously selected from the light emission observation surface side, such as a circle, an ellipse, or a triangular shape with or without edges.
More specifically, the shape may be a track shape or an elliptical shape in which long sides and long axes are arranged in a direction perpendicular to the inter-lead direction as viewed from the light emission observation surface side.

In particular, in an LED lamp in which the mold member 102 has an elliptical shape as viewed from the light emission observation surface side, the shape of the cup tends to appear longer in the minor axis direction of the ellipse than the actual light due to the condensing of the mold member 102. is there. Similarly,
It tends to be shorter than it actually is in the long axis direction. In particular, the stronger the elliptical shape, the stronger the tendency, and the lower the central luminous intensity of the LED lamp. In such an LED lamp, the directional angle can be reduced without lowering the central luminous intensity by forming a cup having a long track shape, an elliptical shape or the like parallel to the long axis of the mold member. Therefore, the effect of the present invention increases as the size of the cup, such as a track or an ellipse, increases.

The mold member and the light emitting element may be formed in close contact with each other, or may not be in close contact with the light emitting element for heat dissipation and stress relaxation. As a specific material of the mold member, various resins such as an epoxy resin, a urea resin, a silicone resin, a fluororesin, a resin having excellent weather resistance such as a polycarbonate resin and a polyimide resin, and a low-melting glass are preferably used. In such a mold member 102,
An organic or inorganic colorant may be contained for the purpose of reducing light emission from the light emitting element 202. Further, a diffusing agent may be contained for the purpose of increasing the viewing angle. As the specific diffusing agent, various types of inorganic barium titanate, titanium oxide, aluminum oxide, silicon oxide, and the like, and organic guanamine resin are suitably used. Further, a fluorescent substance can be contained to emit white light or the like. Specific examples of the fluorescent substance include yttrium activated by cerium.
Various materials such as aluminum-garnet-based fluorescent substances and perylene-based derivatives are suitably used.

When the device is used outdoors for a long time or when the wavelength of light emitted from the light emitting element is short, a light stabilizer may be contained in the resin mold member. Preferable examples of the light stabilizer include benzotriazole, benzophenone, salicylate, cyanoacrylate, and hindered amine. Hereinafter, examples of the present invention will be described, but it goes without saying that the present invention is not limited to only specific examples.

[0038]

【Example】

(Example 1) A main light emission peak of a light emitting element is 660 nm.
GaAlAs semiconductor was used.

Specifically, a semiconductor wafer for an LED chip emitting red light is continuously p-typed by a temperature difference liquid phase growth method.
P-type GaAlAs on a gallium arsenide substrate
An n-type GaAlAs is grown thereon, and a p-type GaAlAs, which is a light emitting region, is formed.

The LED chip was formed by vacuum evaporation as an electrode provided on the light emission observing side, a circular platinum metal film having a diameter of 0.15 mm at the light emission center as an electrode layer. Also,
Gold was formed as an electrode layer by vacuum evaporation on a p-type GaAlAs substrate on the non-emission observation side. After a scribe line was drawn on the semiconductor wafer, the wafer was divided by external force to form LED chips of 350 nm square.

On the other hand, the thickness is about 0.5 mm, the length is 35 mm,
A 150 mm wide iron-containing copper plate was punched out. A plurality of lead terminals connected by tie bars are formed by punching. The leading end of the lead terminal to be a mount lead thus formed was pressed as shown in FIG. 3 to form a recess having a width of 0.1 mm and a depth of 0.3 mm. In this state, the tip of the mount lead was further pressed to form a track-like cup when viewed from the light emission observation surface side.
The size of the cup was about 2 mm ² . The LED chip is die-bonded on the cup thus formed with an epoxy resin containing Ag powder. The surface electrodes of the LED chips and the tips of the inner leads are connected to each other by Au wires having a diameter of 0.03 mm using a wire-holding device to establish electrical continuity.

The tip of the lead terminal electrically connected to the LED chip was placed in a mold and filled with epoxy resin. 1
The epoxy resin was cured at 50 ° C. for 5 hours. By cutting the tie bar, 250 LED lamps having an elliptical mold portion were formed. The directional characteristics of the average of 250 LED lamps thus formed were examined. Less than 2% of the LED lamps had a distorted directivity.

(Comparative Example 1) An LED lamp was formed in the same manner as in Example 1 except that no concave portion was formed when the LED lamp was formed. The directional characteristics of an average of 250 LED lamps were examined. About 23% of the LED lamps had directional distortion characteristics. When the mold member of the LED lamp, which had been uneven, was removed and examined, it was confirmed that the directional characteristics were changed because the end face of the cup was not formed uniformly.

Example 2 As a light emitting element, an In _0.05 Ga _0.95 N semiconductor having a main emission peak of 470 nm was used. L
The ED chip is made of NH ₃ , TMI gas (trimethylindium), TM
G gas (trimethyl gallium) and a dopant gas were flowed together with a carrier gas, and a nitride-based compound semiconductor was formed by MOCVD. By switching between SiH ₄ and Cp ₂ Mg as the dopant gas, a nitride-based compound semiconductor having n-type conductivity and a nitride-based compound semiconductor having p-type conductivity are formed.

As the layer structure of the LED chip, gallium nitride formed at a low temperature on a buffer layer on a sapphire substrate was used. On the buffer layer, n-type gallium nitride as a first contact layer, indium gallium nitride as an active layer which is a light emitting layer, p-type aluminum gallium nitride as a first cladding layer, and p-type as a second contact layer
Gallium nitride was used. (Note that the semiconductor having p-type conductivity is annealed at 400 ° C. or higher after film formation. The active layer is formed as a thin film having a thickness of about 30 nm so as to generate a quantum effect.) The surface of each pn semiconductor was exposed by etching the wafer. Electrodes were formed on each semiconductor surface by a sputtering method. After a scribe line was drawn on the semiconductor wafer, the wafer was divided by external force to form LED chips of 350 nm square.

On the other hand, the thickness is about 0.5 mm, the length is 35 mm,
A 150 mm wide iron-containing copper plate was punched out. A plurality of lead terminals connected by tie bars are formed by punching. The leading ends of the lead terminals to be the mount leads thus formed were pressed as shown in FIG. 4 to form a recess having a width of 0.1 mm and a depth of 0.3 mm. In this state, the tip of a lead terminal serving as a mount lead was pressed to form a track-shaped cup. The size of the cup was about 2 mm ² . Next, the end portion of the lead terminal serving as a mount lead was pressed to form a connection surface of a conductive wire having a smooth flat surface. As shown by the LED lamp in FIG. 5, the concave portion 501 itself was distorted, but the cup 502 was not distorted. Although the tip portion 503 is spread and lowered by press working, it is higher than the end surface of the cup 502 forming one of the two on the lead terminal 504 via a concave portion.

An LED chip is die-bonded on the formed cup with an epoxy resin. When viewed from the light emission observation surface side, one electrode of the LED chip and the tip of the inner lead are wire-bonded with a 30 μφ gold wire, which is a first conductive wire, to establish electrical continuity. Similarly, the tip of the mount lead, which is on the opposite side of the cup via the recess, and the other electrode of the LED chip are wire-bonded with a second conductive wire, a 30 μφ gold wire. The directional characteristics of the 250 LED lamps thus formed and the pull test of the second conductive wire before forming the mold member were performed. In the pull test, the wire was hooked to a substantially central portion of the second conductive wire, pulled up at a pulling rate of 0.5 mm / S, and the average value of the tensile strength when the conductive wire was cut was measured. The conductive wire at the time of the pull test was cut at the pulled position.

(Comparative Example 2) An LED lamp was formed in the same manner as in Example 2 except that no concave portion was formed.
Further, a directional characteristic and a pull test were performed in the same manner as in Example 2. The conductive wire at the time of the pull test was cut at the pulled position.

Example 3 An LED lamp was formed in the same manner as in Example 2 except that the tip of the mount lead was not pressed. Further, a directional characteristic and a pull test were performed in the same manner as in Example 2. The conductive wire at the time of the pull test was cut at the pulled position.

Comparative Example 3 Example 2 was repeated except that the formation of the concave portion and the flattening of the tip of the mount lead were not performed.
An LED lamp was formed in the same manner as described above. Further, a directional characteristic and a pull test were performed in the same manner as in Example 2. The conductive wire in the pull test was cut at the root of the capillary root.

The results are shown in Table 1 together with the results of Example 2, Example 3, Comparative Example 2 and Comparative Example 3. From the result,
Examples 2 and 3 in which a mold member is formed are also LEs having a mold member using Comparative Examples 2 and 3.
It can be seen that the directional characteristics are more stable than the D lamp, and that the LED lamp can be made strong at the time of thermal shock during mounting or long-time use.

[0052]

As described above, by adopting the structure of the first aspect of the present invention, it is possible to form an LED lamp with a very small deviation in directional characteristics with a high yield even if the cup is enlarged.

According to the configuration of the second aspect of the present invention, a more reliable LED lamp can be obtained.

According to the third aspect of the present invention, an LED lamp having more stable light emission characteristics can be obtained.

According to the configuration of the fourth aspect of the present invention, it is possible to provide an LED lamp having a narrower directivity and a higher central emission luminance.

By adopting the method according to the fifth aspect of the present invention, a highly reliable LED lamp having a desired large-sized cup can be formed with high productivity.

By adopting the method according to the sixth aspect of the present invention, a highly reliable LED lamp having desired directional characteristics and high reliability can be formed even in the case of wire bonding to a mount lead.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an LED lamp of the present invention.

FIG. 2 is a schematic plan view showing an LED lamp of the present invention.

FIG. 3 is a schematic view showing a step of forming a concave portion according to the present invention.

FIG. 4 is another schematic view showing a step of forming an upper end portion of the present invention.

FIG. 5 is a schematic enlarged view showing a tip of the LED lamp of the present invention.

FIG. 6 is a schematic sectional view of an LED lamp shown for comparison with the present invention.

[Explanation of symbols]

101, 301, 401: concave portion 102: molded member 103: conductive wire 104: mount lead 105: inner lead 106: light emitting element 201: cup 202 Light-emitting elements 203, 403: Tip of mount lead 302, 402: Tie bar 501: Concave part having buffer function 502: Cup for disposing light-emitting element 503: Mount with wire bonding・ Lead tip 504 ・ ・ ・ Mount lead 505 ・ ・ ・ Inner lead 506 ・ ・ ・ Light emitting element 507 ・ ・ ・ Mold member 601 ・ ・ ・ Light emitting element 602 ・ ・ ・ Mold member 603 ・ ・ ・ Conductive wire 604: Mount lead 605: Inner lead

[Table 1]

Claims (6)

(57) [Claims] An LED lamp having a light emitting element (202) disposed on a cup (201) of a mounting lead (104) and an inner lead (105) electrically connected to the light emitting element. At the tip of the mount lead as viewed from the light emission observation surface side, the cup (201) and the tip of the mount lead (20
LED having a concave portion (101) between the LED and the LED.
lamp. 2. The LED lamp according to claim 1, wherein a conductive wire connected to the light emitting element (202) is wire-bonded to a tip portion (203) of the mount lead. 3. An LED lamp comprising at least a light emitting element (2)
The LED lamp according to claim 1, further comprising a mold member (102) covering the second member (02). 4. The cup (201) has an elliptical shape in plan view and has an ellipsoidal surface, and a direction parallel to a major axis of the ellipse in plan view is longer than a direction perpendicular thereto.
The LED lamp according to claim 3, comprising: 5. A method for forming an LED lamp having a cup in which a light emitting element is disposed at a tip of a mount lead, wherein a recess having a buffer function is formed by pressing a tip of a metal piece serving as the mount lead. A method for forming an LED lamp, comprising: a forming step; and a step of pressing the tip of one metal piece through a recess to form the cup. 6. The method according to claim 5, further comprising, after the step of forming the recess having the buffer function, forming a tip portion for wire bonding by pressing the tip of the other metal piece through the recess. LED lamp forming method.