JP2009080978A - Illuminating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination apparatus which can optimally arrange LEDs (semiconductor light emitting elements) which are provided alternately with electric conductors and has an excellent connecting workability of a bonding wire with the electric conductor and can improve an extraction efficiency of light emitted from the LEDs. <P>SOLUTION: A plurality of LEDs are arranged in a row with spaces on one surface of a mounting board 2. A plurality of electric conductors 6 arranged alternately with each of the LEDs are provided with a metal base 7 which has a trapezoidal cross-section having an inclined side 7c connecting a base side 7a and an upper side 7b parallel with the base side 7a and having a square shape in a plane view, and a metal plated layer 8 bonded on the base 7 except for the base side 7a. The base side 7 is bonded with one surface of the mounting base 1 so that a part of the plated layer bonded on the inclined side 6d of the conductor 6 can face a side surface of the LED. The electric conductor 6 neighboring in an extension direction of the row of the LEDs and the LEDs 11 are electrically connected in series by a bonding wire. The LEDs, the electric conductors and the bonding wire are buried and sealed by a translucent sealing member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lighting device having a semiconductor light emitting element such as a plurality of chip-shaped LEDs (light emitting diodes) and used for, for example, a lighting fixture or a display.

  Conventionally, a plurality of wiring patterns, one end of which is positioned in the recesses, are arranged in a row and in a row on an insulating member formed with a plurality of recesses, and positioned between these wiring patterns. LED chips are arranged in each recess, the LED chip and the wiring pattern adjacent to the LED chip are electrically connected in series by bonding wires, and the LED chip is bonded to the LED chip with a translucent resin injected into each recess. A light source device in which a wire is sealed is known (for example, see Patent Document 1).

In this light source device, the LED chip has a square shape when viewed from the front, and the side surface of the LED chip is formed at a right angle to the upper surface of the chip. At the same time, the wiring pattern is formed by plating a metal film on a copper thin film, and the upper surface of the LED chip is positioned above or below the portion to which the bonding wire of the wiring pattern is connected.
JP 2002-94122 A (paragraphs 0044-0148, FIGS. 1 to 24)

  In a light source device in which LED chips and wiring patterns alternately arranged as in Patent Document 1 are electrically connected in series with bonding wires, each LED chip is placed on a row formed by a plurality of wiring patterns, etc. It is desirable to arrange them properly at intervals so that the directions are not uneven. However, Patent Document 1 neither describes nor suggests technical matters for dealing with such demands. If each LED chip is not properly disposed, variation in the density of the LED chips may affect the heat radiation from each LED chip. As a result, the light emission characteristics of the LED chips may vary, possibly causing uneven brightness.

  In general, when wire bonding is performed, the bonding location needs to be a predetermined temperature or higher. However, Patent Document 1 does not mention a technique for promptly performing this connection when the bonding wire is melted and connected to the portion of the wiring pattern located in the recess. Therefore, in the light source device of Patent Document 1, the waiting time required for the wiring pattern to reach a predetermined temperature is long to start wire bonding, and it is preferable to improve this to improve productivity.

  When the LED chip emits light, light is also emitted from the side surface of the LED chip. However, in the light-emitting device of Patent Document 1, the tip of the part of the wiring pattern located in the recess is located above the upper surface of the LED chip, or the tip of the part of the wiring pattern located in the recess is Since the LED chip is covered with the die-bonded convex base portion, it is not possible to take out light using the tip of the part of the wiring pattern located in the recess.

  An object of the present invention is to appropriately arrange semiconductor light emitting elements provided alternately with electric conductors, to improve the workability of connecting bonding wires to electric conductors, and to take out the light emitted from the semiconductor light emitting elements. The object is to provide a lighting device that can be improved.

  The invention according to claim 1 is an apparatus substrate; a plurality of semiconductor light emitting elements having a first element electrode and a second element electrode and arranged on one surface of the apparatus substrate at intervals and in rows. And: a metal base having a trapezoidal cross section in which the sides extending parallel to each other and the upper side are inclined, and having a square shape when viewed from the front, and the base is attached to the base except for the base A bottom surface of the device substrate so that a part of the plated layer deposited on the slanted side faces a side surface of the semiconductor light emitting device. A plurality of electrical conductors that are alternately disposed with the respective semiconductor light emitting elements, and the electrical conductors that are connected to the electrical conductors and the element electrodes and that are adjacent to each other in a direction in which a row of the semiconductor light emitting elements extends. A bonder in which the semiconductor light emitting element is electrically connected in series. Nguwaiya and; is characterized by comprising a; the semiconductor light emitting device, electrical conductors, and a light transmissive sealing member is embedded a bonding wire.

  In the first aspect of the invention, the device substrate can be an insulating substrate made entirely of an insulating material such as glass epoxy resin, ceramics, glass or the like, and a metal-based substrate can be used to increase heat dissipation of the semiconductor light emitting device. It can be used suitably. In the case of a metal-based substrate, for example, Al (aluminum), Cu (copper), Ni (nickel), etc. can be used for the metal base, and for example, glass epoxy is used for the insulating layer laminated on the metal base to form one surface of the device substrate. Insulating materials such as resin and ceramics can be used. One surface of the device substrate is preferably formed of a white insulating material having a light reflectance of 90% or more in order to improve light extraction efficiency.

  In the invention of claim 1, for example, a chip-like LED (light emitting diode) can be suitably used as the semiconductor light emitting element, and an organic EL element or the like can also be used.

  In the first aspect of the invention, the bottom side of the trapezoidal cross section of the electric conductor refers to the side defined by the bottom surface bonded to the device substrate, and the top side of the trapezoidal cross section of the electric conductor is the device substrate. Indicates the side defined by the top surface parallel to the bottom surface bonded to the surface. For example, Cu can be preferably used for the metal forming the base of the electric conductor, and Au (gold), Ni, Ag (silver), or the like can be preferably used for the metal forming the plating layer of the electric conductor. .

  In the first aspect of the invention, the lengths of the oblique sides of the electrical conductor may or may not be equal. In the invention of claim 1, the field shape of the electric conductor as viewed from the front is a square shape, and refers to a shape in which two opposite sides are parallel to each other, and in this shape, two adjacent sides are In addition to forming a rounded corner, it may be bent and continuous, or may be bent at a right angle without being rounded.

  In the invention of claim 1, for the bonding wire, for example, a fine metal wire such as Au can be used, and the wire diameter is preferably 20 μm to 30 μm.

  In the invention of claim 1, a transparent resin such as a transparent silicone resin can be suitably used for the translucent sealing member, but a transparent epoxy resin or the like can also be used in addition to the transparent resin. Instead of this, translucent low-melting glass or the like can be used. In the invention of claim 1, the phosphor for defining the color of the light transmitted through the sealing member may or may not be mixed in the sealing member.

  In the first aspect of the invention, the column of semiconductor light emitting elements refers to an array of a plurality of semiconductor light emitting elements electrically connected in series. It is sufficient that at least one semiconductor light emitting element column is provided. When a plurality of semiconductor light emitting element columns are provided, a larger amount of light required for illumination can be secured.

  In manufacturing the lighting device of the present invention, in general, the mounting position of the semiconductor light emitting element with respect to the device substrate on which the electrical conductor is disposed is determined by imaging data obtained by imaging the electrical conductor from above with a visual sensor, and semiconductor light emission. Indexing is performed by image recognition that compares and collates with master data stored in advance in a mounting machine (die bonding apparatus) for mounting elements. Thereby, the mounting accuracy of the semiconductor light emitting element is improved by adjusting the feeding of the device substrate in the mounting machine.

  According to the first aspect of the present invention, when an electric conductor having a trapezoidal cross section is imaged from above with a visual sensor, the reflection of the reflection according to the direction of reflection on the upper surface of the electric conductor having a square shape and the inclination on the side of the electric conductor Because the directions are different, it is possible to clearly acquire imaging data of four sides that make a boundary between the upper surface and the side surface of the electric conductor. In addition, since the planar shape of the electrical conductor is a square shape, there are more straight portions in image recognition of this electrical conductor than when the planar shape of the electrical conductor is substantially oval or round. Data and master data can be compared and verified accurately. Therefore, the mounting accuracy of the semiconductor light emitting element on the apparatus substrate is improved using the electric conductor as a reference for positioning, and the semiconductor light emitting element provided alternately with the electric conductor can be properly disposed.

  Furthermore, the electrical connection between the semiconductor light-emitting element and the electrical conductor adjacent to the semiconductor light-emitting element in manufacturing the lighting device of the present invention is performed using a wire bonder, and at that time, the device substrate on which the semiconductor light-emitting element is mounted is mounted. It heats from the other surface side parallel to the said one surface, and wire-bonds in the state which raised the temperature of the electrical conductor etc. to predetermined temperature. In this connection, according to the first aspect of the present invention, the cross section of the electric conductor is trapezoidal, and the widest bottom surface is bonded to one surface of the apparatus substrate, so that the heat of the apparatus substrate is easily supplied to the electric conductor. For this reason, as the time for the electric conductor to reach a predetermined temperature, in other words, the time until the wire bonding starts, the workability of wire bonding for connecting the bonding wire to the electric conductor is improved and the productivity is improved. It can be improved.

In addition, the electric conductor and the semiconductor light emitting element are arranged on one surface of the apparatus substrate so that the oblique side surface of the electric conductor having a trapezoidal cross section faces the side surface of the semiconductor light emitting element. For this reason, light that is emitted from the side surface of the semiconductor light emitting element during lighting, passes through the sealing member, and is incident on the oblique side surface of the electrical conductor is matched with the inclination of the oblique side surface by the oblique side surface of the electrical conductor. Reflected in the take-out direction. Therefore, it is possible to improve the light extraction efficiency of the light emitted from the semiconductor light emitting element. The invention according to claim 2 is the invention according to claim 1, wherein each of the semiconductor light emitting elements has a long square shape when viewed from the front. A conductor row provided with the first element electrode at one end portion in the longitudinal direction of the element and the second element electrode at the other end portion in the longitudinal direction of the semiconductor light-emitting element; The semiconductor light emitting elements are arranged so that the long sides of the semiconductor light emitting elements are parallel to each other.

  In the invention of claim 2, compared with the case where the semiconductor light emitting element is disposed so that the longitudinal direction of the semiconductor light emitting element is orthogonal to the arrangement direction of the electric conductors under the condition that the distance between the electric conductors is the same. As the distance between the electrodes of the semiconductor light emitting elements adjacent to each other and the electric conductor becomes shorter, the attenuation of light entering the oblique side surfaces of the electric conductor from the side face of the semiconductor light emitting element is suppressed, Extraction efficiency can be improved.

  According to a third aspect of the present invention, in the second aspect of the present invention, the respective semiconductors with respect to the wire rows of the respective bonding wires arranged so as to extend linearly in the same direction as the arrangement direction of the respective semiconductor light emitting elements and the respective electric conductors. The tilt angle of the light emitting element is set within ± 10 °.

  In the invention of claim 3, the function and effect of the invention of claim 2 can be further enhanced.

  According to the lighting device of the first aspect of the present invention, the semiconductor light emitting element provided alternately with the electric conductor can be properly disposed, the bonding work of the bonding wire to the electric conductor is good, and the semiconductor light emitting element is generated. It is possible to improve the light extraction efficiency.

  According to the illuminating device of the second and third aspects of the invention, it is possible to further improve the extraction efficiency of light emitted from the semiconductor light emitting element.

  An embodiment of the present invention will be described with reference to FIGS.

  Reference numeral 1 in FIGS. 1 and 2 denotes a COB (chip on board) type lighting device that forms an LED package. The lighting device 1 includes a device substrate 2, a plurality of electric conductors 6, a plurality of semiconductor light emitting elements such as chip-shaped LEDs 11, bonding wires 15, a frame member such as a frame-shaped reflector 21, a sealing member 25, and the like. It is formed with.

  As shown in FIG. 2, the device substrate 2 is made by laminating an insulating layer 4 on the surface of a metal plate 3 made of, for example, an Al plate. The device substrate 2 has a predetermined shape having a size for obtaining a light emitting area required for the lighting device 1, and is a quadrangle, for example, a rectangle as shown in FIG. The insulating layer 4 that forms one surface that is the surface of the device substrate 2 is made of, for example, a synthetic resin plate that is a white insulating material, specifically, a white glass epoxy resin having a light reflectance of 90% or more.

  The plurality of electrical conductors 6 each functioning as an electrode pad are bonded to the insulating layer 4 that forms the surface of the device substrate 2 at the bottom (not shown), so that the longer side 6 a becomes the longer side of the device substrate 2. Are arranged in a row at intervals on the surface of the device substrate 2 so as to be parallel to each other. In the present embodiment, the electrical conductors 6 are arranged at regular intervals, for example, 3 mm to 4 mm in the lateral direction of the device substrate 2 at regular intervals, for example, 3 mm to 4 mm, and 1 mm to the longitudinal direction of the device substrate 2. They are arranged at regular intervals in the range of 4 mm, for example, 3 mm to 4 mm and at equal intervals. Therefore, the electric conductors 6 are arranged in alignment in the vertical and horizontal directions of the device substrate 2.

  Here, the vertical direction of the device substrate 2 refers to the vertical direction perpendicular to the longitudinal direction of the device substrate 2 in FIG. 1, and the lateral direction of the device substrate 2 refers to the lateral direction along the longitudinal direction of the device substrate 2 in FIG. pointing. A row formed by a plurality of electrical conductors 6 arranged so as to extend straight in the lateral direction of the device substrate 2 is referred to as a conductor row. There are a plurality of conductor rows, and they are provided at equal intervals in the vertical direction of the device substrate 2.

  As representatively shown in FIG. 4B, each electric conductor 6 includes a base 7 made of metal, for example, Cu, and a plating layer 8 made of metal, for example, Au. The base 7 has a trapezoidal cross section in which a side 7c extending between the bottom side 7a and the upper side 7b parallel to each other has an oblique shape. The side 7 c is defined by the oblique side surface of the base 7. The base 7 etches a specific portion of the copper thin film formed on the surface of the insulating layer 4 by etching so that a process for forming the oblique side surface on the base 7 is not required. Is provided. The plated layer 8 is attached to the base 7 except for the bottom surface (not shown) that defines the bottom side 7a.

  The planar shape (in other words, the shape seen from the front) of the electric conductor 6 having a shape similar to the shape of the upper surface of the base 7 is an oblong shape, specifically, as representatively shown in FIG. A pair of sides 6a composed of straight lines parallel to each other, another set of sides 6b composed of mutually parallel straight lines extending in a direction perpendicular to these sides 6a, and a corner side 6c across adjacent sides 6a, 6b. The shape is surrounded by.

  As a preferred example, the side 6a is longer than the side 6b adjacent thereto. Therefore, the side 6 a is the long side of the long rectangular electric conductor 6, and the side 6 b is the short side of the long square electric conductor 6. Each corner side 6c has an arc shape. Therefore, the shape of the electric conductor 6 viewed from the front is a rectangle with rounded corners. The electric conductor 6 having rounded four corners does not form a 90 ° sharp corner by etching as compared to the case where a 90 ° sharp corner is formed between the side 6a and the side 6b. Therefore, it is preferable in that the base 7 can be easily formed.

  As shown in FIG. 4 (A), the length L1 of the side 6a and the length L2 of the side 6b forming the straight line portion between the four corners of each electric conductor 6 are both 200 μm to 440 μm and the length of the corner side 6c. Or it is 3 times or more of the length L3 along a horizontal direction. Specifically, the length L3 along the lateral direction of the corner side 6c is 30 μm, and the length L1 of the longer side 6a is 440 μm. Similarly, the length L3 along the vertical direction of the corner side 6c is 30 μm, and the length L2 of the shorter side 6b is less than 440 μm and satisfies the relational expression L2 ≧ L3. Further, as shown in FIG. 4B, the length L4 of the upper side and the length L5 of the lower side of each electric conductor 6 satisfy the relational expression L5 ≧ L4 ≧ 0.9L5. The length L4 of the upper side of the conductor 6 is 500 μm, and the length L5 of the lower side of the electric conductor 6 is 530 μm.

  As shown in FIGS. 1 and 2, a plurality of power supply patterns 9 are provided at both ends in the longitudinal direction of the surface of the device substrate 2 so as to sandwich the conductor row in the direction in which the row extends. In other words, the conductor rows are positioned between the power feeding patterns 9 corresponding to the longitudinal direction of the device substrate 2. These power supply patterns 9 have a copper base provided by etching by etching and an Au plating layer deposited on this surface, and are formed on the device substrate 2 together with the formation of the electric conductor 6. . An external electric wire (not shown) is connected to the power supply pattern 9 by soldering or the like, and the electric supply pattern 9 is electrically connected to an external power source (not shown) via the external electric wire.

  Each LED 11 is formed by laminating a semiconductor light emitting layer on one surface of a light-transmitting element substrate made of, for example, a nitride semiconductor, specifically sapphire. The semiconductor light emitting layer emits, for example, blue light when energized.

  As representatively shown in FIG. 3, the planar shape of each LED 11 is an oblong shape, and when the length of the long side is a and the length of the short side is b, these ratios are 3.0. It is made into the magnitude | size which becomes> = b / a> = 1.2.

The LED 11 has a first element electrode 12 at one end side in the longitudinal direction, and a second element electrode 13 at the other end side in the longitudinal direction. The thickness of each LED 11 is thicker than the thickness of the electric conductor 6 and the power feeding pattern 9 as shown in FIG.

  The plurality of LEDs 11 are mounted on the surface of the device substrate 2 so as to be alternately arranged with the electric conductors 6 forming the conductor rows in the respective conductor rows. Accordingly, the LEDs 11 are also provided at regular intervals and arranged in a straight line. Moreover, each LED 11 is provided so that the first element electrode 12 and the second element electrode 13 are aligned as shown in FIG. 3, and the long sides 11a parallel to each other are parallel to the conductor row. Yes. Here, the long side 11a of each LED 11 is parallel to the conductor row. That is, the long side 11a of the LED 11 is in relation to the center line A of the conductor row indicated by the one-dot chain line in FIG. Even if the LED 11 is not exactly parallel and the LED 11 is slightly inclined and the extended line of the long side 11a intersects, it indicates that the intersection angle (referred to as the LED inclination angle) is within ± 10 °. .

  Such an arrangement of the LEDs 11 is performed using a die bonder (not shown). The die bonder takes an image of the electrical conductor 6 from above with a visual sensor, determines the mounting position of the LED 11 by image recognition for comparing and comparing this imaged data and pre-stored master data, and controls the board feed of the apparatus board 2 The LED 11 is then die-bonded on the device substrate 2. This die bonding is performed by bonding the other surface of the element substrate on which the semiconductor light emitting layer is not laminated to the surface of the device substrate 2 with a die bond material made of a light-transmitting thermosetting resin (not shown). After die bonding, the die bonding material is cured by heating at a temperature higher than its curing temperature.

  As shown in FIG. 1, the LED 11 mounted on the device substrate 2 is adjacent to the LED 11 in the longitudinal direction of the device substrate 2 (in other words, adjacent to the extending direction of the row of the LEDs 11). ) The electrical conductor 6 is connected to each other by a bonding wire 15, and the LED 11 disposed at both ends of the row formed by the LED 11 and the electrical conductor 6 and the feeding pattern 9 approaching the LED 11 are also bonded to the electrical conductor 6. 15 is connected. Each bonding wire 15 is made of a fine metal wire, for example, an Au wire having a wire diameter of 20 μm to 30 μm.

  As shown in FIG. 1, the bonding wires 15 form a wire row arranged so as to extend linearly in the same direction as the arrangement direction of the LEDs 11 and the electric conductors 6 arranged alternately. When the illumination device 1 is viewed from the front, the wire row is provided so as to coincide with the center line A of the conductor row. Each bonding wire 15 electrically connects a plurality of LEDs 11 that are mounted at intervals in the longitudinal direction of the device substrate 2 in series. Therefore, each LED 11 is supplied with power through a pair of power supply patterns 9.

  The bonding wire 15 is attached using an ultrasonic combined thermocompression wire bonder (not shown). The first bond (first bonding) in the wire bonding by the wire bonder is performed on the first element electrode 12 or the second element electrode 13 of the LED 11, and the second bond (second bonding) performed thereafter is This is performed on the electric conductor 6 or the feeding pattern 9. In this case, the device substrate 2 is heated from the back surface so that the device electrodes 12 and 13, the electric conductor 6, and the power supply pattern 9 reach a predetermined temperature.

  The reflector 21 is not provided for each LED 11 or each of the plurality of LEDs 11, but is a single one that surrounds all the LEDs 11 on the device substrate 2, and has a rectangular frame shape as shown in FIG. 1, for example. ing. The reflector 21 is formed of a synthetic resin mixed with a white filler made of magnesium oxide or the like in order to obtain reflection performance on the inner surface. As shown in FIG. 1, the reflector 21 crosses the power supply patterns 9 provided at both ends in the longitudinal direction of the device substrate 2 when viewed from above.

  The sealing member 25 is filled in the reflector 21, and is inserted into the reflectors 21 of all the electrical conductors 6, all the LEDs 11, all the bonding wires 15, and the feeding pattern 9 accommodated in the reflector 21. These end portions are buried to seal them. The sealing member 25 is made of a translucent resin such as a thermosetting silicone resin. The sealing member 25 is cured by being heated in a heating furnace or the like after being filled in the reflector 21 in an uncured state.

  The sealing member 25 is mixed with a phosphor (not shown), preferably in a uniformly dispersed state. The phosphor is excited by a part of the light emitted from each LED 11 and emits light having a color different from that of the light emitted from the LED 11, thereby defining the color of the illumination light emitted from the illumination device 1. To do. In the present embodiment, in order to change the illumination light of the illumination device 1 to white light, a phosphor that mainly emits yellow light that is complementary to the blue light emitted by each LED 11 is used.

  In the manufacture of the lighting device 1 having the above-described configuration, the LEDs 11 are alternately arranged with respect to the electric conductors 6 on the surface of the device substrate 2 on which the electric conductors 6 and the power feeding patterns 9 are already mounted using a die bonder. Implemented.

  In the mounting of the LED 11, the electrical conductor 6 adjacent to the left and right direction of the planned mounting position (in other words, the direction in which the conductor row extends with respect to the planned mounting position) and / or the vertical direction (in other words, the planned mounting position). The electrical conductor 6 adjacent in the direction in which the conductor rows are arranged in parallel with respect to the position is imaged from above with a visual sensor of the die bonder, and the shape and position of the electrical conductor 6 are determined by the data processing unit of the die bonder. Recognize images. The die bonder then compares the recognized image data with the master data stored in the data processing unit, and determines the position of the LED 11 on which the electrical conductor 6 is mounted based on the comparison and verification. Further, the die bonder feeds the device substrate 2 according to the determined position data, and then mounts the LED 11 by die bonding at the position determined via the die bonding material.

  In the imaging by the visual sensor in such mounting of the LED 11, the cross-sectional shape of the electric conductor 6 is trapezoidal. Therefore, the direction of reflection on the upper surface of the electric conductor 6 whose front shape is a square shape and the oblique angle of the electric conductor 6. The direction of reflection differs according to the inclination on the side surface. Thereby, the imaging data of the four sides forming the boundary between the upper surface and the side surface of the electric conductor 6 can be clearly obtained. In addition, since the planar shape of the electric conductor 6 is a square shape, the image data of the electric conductor 6 can be recognized when the electric conductor 6 is recognized as compared with the case where the planar shape of the electric conductor 6 is substantially oval or round. And master data can be compared and verified accurately.

  As described above, the mounting position of the LED 11 is determined using the electric conductor 6 having a square shape when viewed from the front as a positioning reference and the LED 11 is mounted on the apparatus substrate 2. Although the mounting accuracy is ± 40 μm to 100 μm, the mounting accuracy of the mounted LED 11 is improved, and the mounting accuracy can be within ± 40 μm. As a result, the electric conductors 6 arranged at equal intervals and the LEDs 11 provided alternately are die-bonded at appropriate positions, so that the inclination angle of each LED 11 with respect to the center line A can be arranged within ± 10 °.

  Further, in the manufacture of the lighting device 1 having the above-described configuration, each LED 11 to be electrically connected in series and the electric conductor 6 or the power feeding pattern 9 adjacent thereto are connected via bonding wires 15 wired over them. Electrically connected, this connection is made using a wire bonder.

  In the wire bonding using the wire bonder, the device substrate 2 on which the LED 11 is mounted is heated from the back side by the wire bonder heating device, and the temperature of the electric conductor 6 and the like is raised to a predetermined temperature, and the first LED 11 of the LED 11 is mounted. After the bonding wire 15 is first bonded to the element electrode 12 or the second element electrode 13, the electric conductor 6 or the power supply pattern 9 in a state where the bonding wire 15 is heated by moving the wire bonder with an XY table or a capillary. The second bond is performed by the pressing load and ultrasonic vibration. The pressing load by the capillary is larger in the case of the second bond than in the case of the first bond, but the LED 11 having a low strength due to the chip shape is not applied with the pressing load in the case of the second bond. There is no fear that the LED 11 is damaged along with the second bond.

  In the wire bonding described above, the cross section of the electric conductor 6 has a trapezoidal shape as described above, and the widest bottom surface is bonded to the apparatus substrate 2, so that the heat of the apparatus substrate 2 is easily supplied to the electric conductor 6. . For this reason, the time for the electric conductor 6 to reach a predetermined temperature, in other words, the waiting time until the start of wire bonding is shortened, and accordingly, the workability of wire bonding for bonding the bonding wire 15 to the electric conductor 6 is improved. Productivity.

  Furthermore, the electric conductors 6 and the LEDs 11 are both rectangular, specifically, long rectangular, and are arranged alternately on the surface of the device substrate 2 with the longitudinal direction aligned. Thereby, compared with the case where wire bonding is performed in a state where each LED 11 is arranged so as to be orthogonal to the center line A of the conductor row formed by the plurality of electric conductors 6, the adjacent electric conductor 6 and the LED 11 The distance between the ends is brought closer.

  For this reason, the length of the bonding wire 15 over the adjacent electrical conductor 6 and the LED 11 can be shortened. At the same time, the bonding wires 15 can be wired so as to be positioned on the center line A when viewed from above.

  In addition, since the electric conductor 6 has a long square shape and the bonding wire 15 is second bonded to both ends in the longitudinal direction, the distance between the bonding points where the bonding wire 15 is second bonded to the electric conductor 6 is small. become longer. Therefore, the capillary (bonding tool) for routing the bonding wire 15 to be connected later to the electric conductor 6 is prevented from interfering with the bonding wire 15 previously connected to the electric conductor 6 and is connected first. It is possible to prevent the bonding wire 15 from being damaged by the capillary. This is possible even when the electric conductor 6 is formed in a quadrangular shape having four sides having the same length as the long side. However, in this case, since the area of the electric conductor 6 is increased, the number of conductor rows mounted on the surface of the device substrate 2 having a predetermined size may be reduced and the insulating layer 4 of the device substrate 2 may be reduced. This is not preferable because the light reflection area may decrease, and the light extraction efficiency decreases accordingly.

  As described above, since the distance between the adjacent electrical conductors 6 and the ends of the LEDs 11 is reduced, when the lighting device 1 is turned on, the distance from the side surface 11b positioned in the direction in which the conductor row of the LEDs 11 extends is increased. Attenuation of light entering the oblique side surface 6d of the electric conductor 6 positioned so as to face the light is suppressed. Therefore, the light extraction efficiency of the lighting device 1 can be improved by the reflection of light at the oblique side surface 6d of the electric conductor 6.

  In this case, as described above, by improving the mounting accuracy of the LED, the inclination angle of the LED 11 with respect to the wire row of the bonding wires 15 arranged to extend linearly in the same direction as the arrangement direction of the LED 11 and the electric conductor 6 is increased. Since the angle is within ± 10 °, the light enters the oblique side surface 6d of the electric conductor 6 from the LED 11 due to a right angle of the LED 11 (from here, the light emission is less than that of the side surface of the LED 11). It is suppressed that the light to do decreases. Thereby, the light extraction efficiency of the lighting device 1 can be further improved.

  In addition, as described above, the inclination angle of each LED 11 being within ± 10 ° means that the LEDs 11 are properly arranged so as to be equally spaced and not unevenly oriented. . Therefore, variation in heat dissipation from each LED 11 caused by variation in the arrangement density of each LED 11 and the like is suppressed, and variation in light emission characteristics of each LED 11 based on the variation is suppressed, so that uneven brightness can be prevented. .

The front view shown in the state which partly cut away the illuminating device which concerns on one Embodiment of this invention. Sectional drawing of the illuminating device shown along F2-F2 line | wire in FIG. The front view which expands a part of illuminating device of FIG. 1, and shows the relationship between LED, an electrical conductor, and a bonding wire. FIG. 5A is an enlarged front view showing an electrical conductor included in the lighting device of FIG. 1, and FIG. 5B is a cross-sectional view taken along line F4B-F4B in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Illuminating device, 2 ... Device substrate, 4 ... Insulating layer which formed one side of device substrate, 6 ... Electrical conductor, 6a ... Long side of electrical conductor, 6b ... Short side of electrical conductor, 6c ... Electricity Corner side of conductor, 6d: oblique side surface of electric conductor, 7 ... base, 7a ... bottom side of base, 7b ... upper side of base, 7c ... other side of base, 8 ... plated layer, 9 ... feeding pattern, 11 ... LED (semiconductor light-emitting element), 11a ... long side of LED, 11b ... side face of LED, 12 ... first element electrode, 13 ... second element electrode, 15 ... bonding wire, 25 ... sealing member

Claims (3)

A device substrate;
A plurality of semiconductor light emitting elements each having a first element electrode and a second element electrode and arranged in a row and in a row on one surface of the device substrate;
A metal base having a trapezoidal cross-section in which the sides extending parallel to each other and the upper side are slanted, and the shape seen from the plane is formed in a square shape, and is applied to the base except the base The base is bonded to one surface of the device substrate so that a part of the plating layer deposited on the oblique side is opposed to the side surface of the semiconductor light emitting element. A plurality of electrical conductors arranged alternately with each of the semiconductor light emitting elements;
A bonding wire electrically connected in series to the electrical conductor and the semiconductor light emitting element adjacent to each other in the direction in which the row of the semiconductor light emitting elements extends and connected to the electrical conductor and the element electrode;
A translucent sealing member in which the semiconductor light emitting element, the electrical conductor, and the bonding wire are embedded;
An illumination device comprising:   Each of the semiconductor light emitting elements has a long square shape when viewed from the front, and the first element electrode is provided at one end side in the longitudinal direction of these semiconductor light emitting elements and at the other end side in the longitudinal direction of the semiconductor light emitting element. The semiconductor light emitting element is provided so that the second element electrode is provided and a conductor row formed by the electric conductors and a long side of each semiconductor light emitting element are parallel to each other. Item 2. The lighting device according to Item 1.   The inclination angle of each semiconductor light emitting element with respect to the wire array of each bonding wire arranged so as to extend linearly in the same direction as the arrangement direction of each semiconductor light emitting element and each electric conductor is within ± 10 °. The lighting device according to claim 2.

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