JP2013171912A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device which permits a circuit board and itself to be easily and firmly joined together via small solder lands and also can reduce poor bonding.SOLUTION: The light-emitting device includes a substrate 11 having an almost rectangular mounting portion, including a notched portion, at opposite ends thereof, a light-emitting element 13 mounted on the substrate, and electrode layers formed on bonding surfaces which are side faces of the substrate perpendicular to the light-emitting element mounted face and exposed to the notched portions. The mounting portions 15A and 15B each include an electrode non-formed portion 19 in which no electrode layer is formed over a side constituted by the end face and the bonding face of the mounting portion.

Description

  The present invention relates to a light emitting device equipped with a light emitting element such as a light emitting diode (LED) element.

  A light-emitting device in which a light-emitting element such as an LED element is mounted on an element substrate has been conventionally used in lighting, backlights, industrial equipment, and the like. One type of such a light emitting device is a side view type light emitting device that is mounted on a circuit board and emits light in a direction parallel to the circuit board.

  As a side view type light emitting device, there is one disclosed in Patent Document 1.

Japanese Patent Laid-Open No. 8-242019

  In the light emitting device as described above, there are few metal surfaces exposed on the mounting surface facing the circuit board. Therefore, in order to solder the light emitting device and the circuit board, a fillet is formed even on the surface of the element substrate perpendicular to the light emitting device mounting surface of the circuit board, where a metal surface with high solder wettability exists. It must be mounted with solder attached. Therefore, in order to ensure the bonding strength between the light emitting device and the circuit board, it is necessary to form a large solder land on the circuit board and use a large amount of solder.

  The present invention has been made in view of the above-described points, and is capable of easily and firmly joining a circuit board and a light-emitting device through a small solder land and capable of reducing joint failure. An object is to provide an apparatus.

  The light emitting device of the present invention includes a substrate having a mounting portion including a substantially rectangular cutout at both ends, a light emitting element mounted on the substrate, and a side surface exposed to the cutout portion perpendicular to the light emitting element mounting surface of the substrate. And an electrode layer formed on the bonding surface, and the mounting portion includes an electrode non-forming portion in which no electrode layer is formed across a side formed by the end surface of the mounting portion and the bonding surface. It is characterized by having.

  In addition, the method for manufacturing a light emitting device of the present invention includes a step of forming a plurality of substantially rectangular through holes on a substrate so as to be arranged in the major axis direction and the minor axis direction of the through holes, and the plurality of through holes. The electrode layer and the electrode non-formation part where the substrate is exposed extend in the minor axis direction of the electrode non-formation part where the substrate is exposed on the side surface along the major axis direction of the substrate side surface exposed inside A step of cutting the substrate in a longitudinal direction so as to cross a plurality of through holes in the step of cutting the substrate, and a step of cutting the substrate in a long axis direction. Cutting the substrate in the minor axis direction so as to cross the through hole and the electrode non-forming portion.

  The light emitting device of the present invention has a metal electrode portion having high solder wettability on the joint surface between the element substrate and the circuit substrate. Accordingly, a large solderable region can be obtained on the surface of the light emitting device facing the circuit board, and a small solder land can be used for strong bonding between the light emitting device and the circuit board. Moreover, the light emitting device of the present invention has no electrode portion at the end of the joint surface with the circuit board, which becomes a cut surface when the element substrate and the circuit board are manufactured. Thereby, it is possible to avoid the formation of burrs generated on the bonding surface of the element substrate to the circuit board at the time of cutting in manufacturing, and to make the bonding between the element substrate and the circuit board easy and strong.

It is a top view of the light-emitting device which concerns on Example 1 of this invention. It is a bottom view of the light-emitting device concerning Example 1 of the present invention. It is a side view of the light-emitting device which concerns on Example 1 of this invention. It is a side view of the end surface vicinity of the light-emitting device which concerns on Example 1 of this invention. It is a side view of the end surface vicinity of the light-emitting device which concerns on Example 1 of this invention. It is a top view of the light-emitting device concerning Example 1 before individualization of the present invention. It is a top view of the modification of the light-emitting device of this invention. It is sectional drawing of the modification of the light-emitting device of this invention. It is a side view of the modification of the light-emitting device of this invention. It is a top view of the modification of the light-emitting device of this invention. It is a bottom view of the modification of the light-emitting device of this invention. It is a side view of the modification of the light-emitting device of this invention. It is a side view of the modification of the light-emitting device of this invention.

  Below, the light-emitting device 1 which concerns on Example 1 of this invention is demonstrated, referring FIG. FIG. 1 a is a top view of the light emitting device 1 mounted on the circuit board 2 as seen from the light emitting surface side. 1b is a bottom view of the light emitting device 1, FIG. 1c is a side view of the light emitting device 1 as viewed from the mounting surface side, and FIGS. 1d and 1e are views of the circuit board of the light emitting device 1. FIG. It is a side view seen from the surface perpendicular | vertical to a mounting surface, and only the area | region Z1 of the end surface vicinity enclosed with the dashed-dotted line of FIG. 1b is shown. In addition, in FIG. 1b, c, d, the circuit board 2 is omitted.

  The light emitting device 1 is a side view type light emitting device mounted on a circuit board 2 as shown in FIG. The light emitting device 1 is joined via solder lands 9 and solder 10 on the light emitting device mounting surface of the circuit board 2.

  The element substrate 11 is an insulating substrate having a substantially rectangular planar shape made of resin, ceramic, or the like, and has a light emitting element mounting surface on which the light emitting element 13 is mounted. The element substrate 11 has a substantially rectangular notch at each of the four corners when viewed from the direction perpendicular to the element mounting surface. The element substrate 11 is provided with mounting portions 15A and 15B including these notches as regions for mounting the light emitting device 1 on the circuit board and supplying power to the light emitting device 1 at both ends. . One side surface perpendicular to the element mounting surface of each of the mounting portions 15A and 15B forms a bonding region 16 (a portion surrounded by a broken line portion in FIG. 1c) to be bonded to the solder land 9 of the circuit board 2. That is, the one side surface is bonded to the solder land 9 of the circuit board 2 as a bonding surface of the light emitting device 1. Further, the notch has a long side and a short side, and the side surface of the substrate on the long side exposed at the notch is included in the bonding surface of the light emitting device 1.

  The strip electrodes 17A and 17B are electrode layers formed of a conductor such as Cu plating, and are formed in a strip shape from the upper surface of the element substrate 11 through the side surface to the lower surface so as to be wound around the mounting portions 15A and 15B. Has been. The strip electrodes 17A and 17B are not formed on the tip surfaces of the mounting portions 15A and 15B and the strip-shaped electrode non-forming portion 19 in the vicinity of the tip surfaces. That is, in the mounting parts 15A and 15B, an electrode non-formation part is formed over the side (the side indicated by reference numeral 19A in FIG. 1c) formed by the end surface of the mounting part and the joint surface. In the electrode non-formation part 19, the element substrate 11 is exposed. Then, on the side surface of the substrate on the long side exposed at the notch, an electrode non-formation region (a part of the electrode non-formation portion 19, a symbol in FIG. 1C) from the substrate end side (the cut surface side of the substrate). A region indicated by 19B) is formed. The belt-like electrodes 17A and 17B are joined to the solder lands 9 of the circuit board 2 in the joining region 16, so that the circuit board 2 and the light emitting device 1 are fixed and power is supplied from the circuit board 2 to the light emitting device 1. Is called.

  In the light emitting device 1, since the strip electrodes 17A and 17B having high solder wettability are formed in the joint region 16 facing the solder land 9 of the circuit board 2, the circuit through the solder 10 only in the joint region 16 is provided. Electrical connection between the substrate 2 and the light emitting device 1 is possible, and a large area for soldering can be secured. Therefore, unlike the conventional light emitting device, it is not necessary to provide a solder land having a large area on the circuit board 2 and to attach and fix the solder so as to form a fillet with respect to the front and back surfaces of the board 11. The light-emitting device 1 and the circuit board 2 can be firmly joined by a small solder land and a small amount of solder.

  Further, as described above, the light emitting device 1 has the electrode non-formation portion 19 on which the metal serving as the electrode does not exist on the side surface in the vicinity of the front end surfaces of the mounting portions 15A and 15B that are cut in the individualization at the time of manufacture. doing. Therefore, it is possible to prevent the occurrence of metal cutting burrs in the bonding region 16 when cutting the light emitting device 1 into individual pieces, and when mounting the circuit board 2 on the circuit board 2, bonding defects such as the light emitting device 1 being inclined due to the protruding cutting burrs are prevented. It can be resolved.

  The light emitting element 13 is an LED element and is mounted on the strip electrode 17B. The light emitting element 13 has electrodes on the upper surface and the lower surface of the element, the electrode on the lower surface of the element is electrically connected to the belt-like electrode 17B, and the electrode on the upper surface of the device is electrically connected to the belt-like electrode 17A and the bonding wire 21. .

  The light emitting element 13 and the bonding wire 21 may be sealed with a sealing resin (not shown) for protection against impact from external environment or moisture.

  In FIG. 1a, in order to briefly describe the mounting state of the light-emitting device 1 of Example 1, the solder 10 is not shown in an expanded state (including a creeping up state). As shown in FIG. 1E, fillets are formed on the upper surface side and the bottom surface side of the light emitting device.

  The light emitting device 1 having the above configuration is formed by cutting the light emitting device assembly 3 as shown in FIG. For simplification of the drawing, FIG. 2 shows a part of the light emitting device assembly 3.

  The light emitting device assembly 3 is formed as follows.

  First, a drill having a substantially rectangular (for example, square, rectangular, or land track shape) through-hole 27 lined up in a substantially rectangular major axis direction and a minor axis direction on a substrate having copper plates on its upper and lower surfaces. Or by punching. The region between the through holes 27 arranged in the minor axis direction becomes the mounting portions 15A and 15B having the bonding region 16 after the individualization process described later.

  Next, copper plating is performed on the entire substrate to form a copper layer inside the through hole 27 and on the side surface of the substrate outer periphery. That is, a copper layer is formed so that the entire surface of the substrate is covered with copper, and an electrical connection is formed between the upper surface and the lower surface of the substrate.

  Next, the copper layer is removed by, for example, a photolithography method or an EB method using an electron beam, and the electrode non-formation portion 19 and the strip electrodes 17A and 17B are formed. Here, the electrode non-forming portion 19 removes the copper layer along a straight line that passes through the center of the long side of the through hole 27 and extends in the direction along the short side of the through hole on the top and bottom surfaces of the substrate. It is formed by. In the individual through hole 27, the electrode non-forming portion 19 removes the copper layer along a straight line that is perpendicular to the upper surface of the substrate and passes through the center of the long side on the side surface having the long side in the through hole 27. It is formed by doing. Thereafter, the light emitting element 13 is mounted on the surface of the portion that becomes the strip electrode 17B of the light emitting device 1 after separation, and each of the upper surface of the light emitting element 13 and the surface of the portion that becomes the strip electrode 17A after separation. Are connected by a bonding wire 21.

  Thereafter, if necessary, the light emitting element 13 and the bonding wire 21 are sealed with a sealing resin (not shown).

  The light-emitting device assembly 3 thus completed is cut along a plurality of cutting lines A and B indicated by broken lines in the drawing in a mode in which the through hole 27 is divided into four in the major axis direction and the minor axis direction. To separate the light emitting device 1. At this time, the short-axis direction cutting line A exists in a linear region formed by the electrode non-forming region.

  The light-emitting device 1 formed in this way has one of the strip electrodes 17A and B made of conductive metal or the like that can be solder-bonded in the bonding region 16 facing the solder land 9 of the circuit board 2 to be mounted. The part is formed. Since the joining region 16 corresponds to the long side portion of the substantially rectangular cutout, the formed strip-like electrodes 17A and 17B have a sufficient area for joining while having an electrode non-forming region at the end. . Therefore, a large solderable region can be obtained on the surface of the element substrate 11 facing the solder land 9, and the light emitting device 1 and the circuit board 2 can be easily and firmly joined with a small solder land and a small amount of solder. It is possible.

  Further, in cutting along the broken line A when the light emitting device 1 is singulated, the strip electrodes 17A and 17B, which are conductors such as metal, are not cut because the electrode non-forming portion 19 is formed. Therefore, in the light emitting device 1, burrs caused by cutting the electrode portion together with the element substrate 11 do not occur on the bonding region 16 that becomes the mounting surface with the solder land 9. Therefore, it is possible to eliminate a bonding failure between the light emitting device 1 and the circuit board 2 such as an inclination caused by the presence of protruding cutting burrs.

  In the above embodiment, the light-emitting device 1 having a pair of electrodes and mounting one light-emitting element has been described, but has three or more electrodes that are electrically separated to mount two or more light-emitting elements. A light emitting device can also be provided. For example, the light emitting device 4 shown in FIG. 3a, FIG. 3b, which is a cross-sectional view taken along line 3b-3b in FIG. 3a, and FIG. 3c, which is a side view seen from the mounting surface side with the circuit board, are electrically connected to each other. The four strip electrodes 29A, 29B, 29C and 29D are separated. The strip electrodes 29A and 29D extend through the inside of the element substrate 11 as shown in the sectional view 3b. By forming the electrodes in this way, it is possible to configure a light emitting device capable of lighting a plurality of light emitting elements separately.

  Also in the light emitting device 4, electrodes 29 </ b> A, 29 </ b> B, 29 </ b> C, and 29 </ b> D having high solder wettability are formed in the bonding region 16 facing the solder lands 9 of the circuit board 2. Therefore, it is possible to electrically connect the circuit board 2 and the light emitting device 4 via the solder only in the bonding region 16, and it is possible to sufficiently achieve the solder fixing to the circuit board 2 only in the bonding region 16. Therefore, unlike the conventional light emitting device, it is not necessary to fix and connect the solder widely to the upper surface and the lower surface of the substrate 11, and the light emitting device 4 and the circuit board 2 can be firmly joined with a small amount of solder. is there.

  Further, similarly to the light emitting device 1, since the electrode non-forming portion 19 is formed in the vicinity of the front end surfaces of the mounting portions 15A and 15B, burrs are generated on the bonding region 16 by cutting the electrodes 29A and 29D. do not do. Accordingly, it is possible to eliminate a bonding failure such as the light emitting device 4 being inclined due to the protruding cutting burr when mounted on the circuit board 2. The light emitting device 4 as shown in FIG. 3 is formed by further forming two electrode non-formation portions in FIG. 2 so as to be parallel to the cutting line A and across the through hole, the substrate top surface, and the substrate bottom surface. can get.

  In the above embodiment, the electrode non-forming portion 19 is wound around the mounting portions 15A and 15B in a strip shape, but the electrode non-forming portion 19 may exist only in the bonding region 16. Such a light emitting device 5 will be described with reference to FIGS.

  FIG. 4A is a top view of the light emitting device 5 as seen from the light emitting surface side. 4b is a bottom view of the light emitting device 1, FIG. 4c is a side view of the light emitting device 1 as viewed from the mounting surface side with the circuit board, and FIG. 4d is a mounting surface of the light emitting device 4 with the circuit board. FIG. 4B is a side view seen from the vertical surface side, and shows only a region Z2 in the vicinity of the end surface surrounded by a one-dot chain line in FIG. 4B.

  As shown in FIGS. 4a to 4d, electrodes are also formed on the element mounting surface, the bottom surface, and the end of the side surface opposite to the bonding surface, which is the electrode non-forming portion 19 in the light emitting device 1. The electrode non-forming part 19 exists only in the bonding region 16.

  In this way, by not forming an electrode layer in at least the region extending along the cutting portion at the end of the bonding region 16, at least the bonding region 16 does not generate cutting burrs, and bonding by protruding cutting tension is performed. It is possible to improve defects. Even in this case, since the electrode layers 17A and 17B are formed in the bonding region 16, the light emitting device 5 and the circuit board 2 can be firmly bonded with a small amount of solder.

  The light emitting device 5 as shown in FIGS. 4a to 4d can be obtained by forming the electrode non-formed portion only in the through hole in FIG. 2 and cutting it without forming it on the top and bottom surfaces of the substrate.

  In each of the above embodiments, notches are provided at the four corners of the substrate 11, but notches may be provided only at two locations corresponding to the bonding surface.

  Various numerical values, dimensions, materials, and the like in the above-described embodiments are merely examples, and can be appropriately selected according to the application and the light-emitting element used.

1, 4, 5 Light-emitting device 2 Circuit board 3 Light-emitting device assembly 9 Solder land 10 Solder 11 Element substrate 13 Light-emitting element 15A Mounting portion 15B Mounting portion 16 Bonding region 17A Strip electrode 17B Strip electrode 19 Electrode non-forming portion 21 Bonding wire 27 Through hole 29A Strip electrode 29B Strip electrode 29C Strip electrode 29D Strip electrode cutting line A, B

Claims (7)

A substrate having a mounting portion including a substantially rectangular cutout at both ends;
A light emitting device mounted on the substrate;
A side surface exposed to the cutout portion perpendicular to the light emitting element mounting surface of the substrate as a bonding surface, and an electrode layer formed on the bonding surface,
The light emitting device, wherein the mounting portion includes an electrode non-forming portion in which an electrode layer is not formed across a side formed by an end surface of the mounting portion and the joint surface.   The light emitting device according to claim 1, wherein the electrode non-forming portion is formed in an end region including the side on the bonding surface.   The light emitting device according to claim 1, wherein the electrode layer is formed on the mounting portion so as to wind the mounting portion. The notch has a shape having a longitudinal direction and a short direction,
4. The light emitting device according to claim 1, wherein the electrode non-forming portion is formed in the longitudinal direction region on the side surface of the substrate exposed to the notch. 5. A plurality of the light emitting elements are mounted on the substrate,
The electrode layer includes a plurality of electrode portions that are formed so as to wind the mounting portion in one mounting portion and are electrically separated from each other and electrically joined to the light emitting elements. The light emitting device according to claim 1, wherein the light emitting device is a light emitting device. Forming a plurality of substantially rectangular through holes on the substrate so as to be arranged in a plurality of major and minor axis directions of the through holes;
An electrode layer and an electrode non-formation part where the substrate is exposed are formed on a side surface along the major axis direction of the substrate side surface exposed in the plurality of through holes. Forming the forming parts so as to be connected by a straight line extending in the minor axis direction;
Cutting the substrate,
In the step of cutting the substrate,
Cutting the substrate in the major axis direction across the plurality of through holes;
And a step of cutting the substrate in the minor axis direction so as to cross the plurality of through holes and the electrode non-formation portion. In the step of forming the electrode layer and the electrode non-forming portion,
The electrode layer is formed so as to continuously go around a surface of the substrate on which the light emitting element is mounted, and the electrode non-forming portion is on a straight line connecting the electrode non-forming portions of the plurality of through holes. The method of manufacturing a light emitting device according to claim 6, wherein the light emitting device is formed.

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