JP3312121B2 - Manufacturing method of light emitting diode of chip component type - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a method for manufacturing <br/> extremely small and thin chip-type light-emitting diodes can be mounted directly without going through the bonding wire on the surface of the wiring board.

[0002]

2. Description of the Related Art Light emitting diodes are used as backlights of display panels and liquid crystal display devices, indicators of portable equipment, illumination switches, light sources of OA equipment, and the like. I have.

In this light-emitting diode, an electrode 22 on the lower surface of a light-emitting diode 21 is bonded to the tip of one of a pair of lead terminals 26 facing each other with a gap with a conductive paste 24, and the electrode 23 on the upper surface is bonded to a bonding wire. 6A is connected to the tip of the other lead terminal 27 by a gold wire 25, and the same one is arranged in the longitudinal direction as shown in FIG. 6A, and these are molded in a transparent resin 28. . In this example, the left lead terminal 27 in the figure is a cathode, and the right lead terminal 26 is an anode.
The width W and height H are L = 2.9 mm, W = 1.5 mm, H = 1.1 mm, respectively.
And the distance between the light emitting diodes is 0.8 mm. Then, the light emitting diodes made by molding are connected to respective lead terminals 26 and 27 on a wiring pattern on a wiring board (not shown).
Are mounted, and both are soldered and mounted.

[0004]

However, the above-mentioned conventional light emitting diode has one of two lead terminals projecting upward.
6, the lower electrode 22 of the light emitting diode chip 21 is adhered to the tip of the light emitting diode chip 21.
7 and molded in the resin 28 to protect the gold wire 25 and the like from external force, the height of the chip itself is only 0.2 to 0.3 mm, but the height of the entire product However, as described above, it is about three times as large as 1.1 mm, and a considerable space is required on the wiring board. Further, since there are many constituent members, there is a problem that the material cost and the processing cost are increased and the cost of the product is increased.

Therefore, an object of the present invention is to improve the structure of the light emitting diode chip itself so that it can be directly mounted on the surface of the wiring board without using bonding wires.
An object of the present invention is to provide a manufacturing method capable of manufacturing an extremely small and thin light emitting diode of a chip component type at a low cost, which can reduce the cost and does not require the supply of a brazing material at the time of mounting.

[0006]

In order to achieve the above object, a method of manufacturing a chip-part type light emitting diode according to the present invention is provided.
Are provided on the front and back of the light emitting diode in the wafer state.
The positive and negative electrodes are coated with brazing
After forming the coating layer, at least one brazing
Attaching the coating layer to the sheet and dicing the wafer
Side of each chip separated by this dicing
At least the side of the surface that will be the mounting surface facing the wiring board
The surface is coated with an insulating material . In addition, to coat with insulating material,
Mask the surface opposite to the surface pasted on the sheet of each chip.
King can be coated with insulating material
preferable.

[0007] emitting diode produced by the method of the present invention, positive provided on both end surfaces of the chip, the surface of the negative electrode portion is coated with a filter cormorants material, a counterflow mounting surface wiring board The side surface of the chip is coated with an insulating material. Therefore, the size of the light emitting diode can be reduced to a size substantially equal to the size of the chip itself, and the thickness can be reduced. Also, the side surface coated with the insulating material of the light emitting diode is opposed to the wiring board surface, and the positive and negative electrode portions are
When they are placed on one and the other wiring patterns on the wiring substrate and heated in a furnace or the like to a temperature equal to or higher than the melting point of the brazing material, the brazing materials of both electrode portions are melted and brazed to the wiring pattern. At this time, the external force applied to the chip at the time of mounting is reduced by the coating layer of the insulating material on the side surface, so that the reliability of the mounted light emitting diode is improved and the coating layer of the insulating material at the time of soldering such as reflow is used. A short circuit between the two electrodes due to a brazing material such as solder can also be prevented.

[0008]

[0009]

[0010]

Further, according to such a light emitting diode , the work of connecting to the pattern of the wiring board can be performed easily, quickly and with high precision without the supply of solder or the like, and the number of parts reduces the material cost and processing cost. Together with this, the cost of the mounting operation can be reduced. The light emitting diode of the present invention
According to the manufacturing method, such a light emitting diode is manufactured.
However, brazing material coating and insulation material
Can be performed collectively in the state of the wafer,
Extremely small and thin light emitting diodes with chip components
It can be manufactured at low cost.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a perspective view showing a chip component type light emitting diode according to one embodiment of the present invention. This light emitting diode is composed of P
A mold layer 1 and an N-type layer 2, and a P-type, provided on the end faces of the P-type and N-type
N-type electrode portions 3 and 4, solder coating layers 5 and 6 as brazing materials provided on the surfaces of the electrode portions 3 and 4,
Insulating resin coating layer 7 as an insulating material provided on the surface of four side surfaces other than coating layers 5 and 6
(See FIGS. 2 (C) and 2 (D)) and presents a rectangular chip.

The light emitting diode having the above configuration is mounted on a wiring board as follows. That is, as shown in FIG. 1A, the light emitting diode chip is turned sideways, and the solder coated electrode portions 3 and 4 at both ends are connected to the wiring board 8.
It is placed vertically on the upper and lower wiring patterns 9a and 9b, and the center of the bottom coated with the insulating resin is temporarily fixed to the wiring substrate 8 with an adhesive 10. Next, when the wiring board 8 is put into a reflow furnace heated to a temperature equal to or higher than the melting point of the solder, FIG.
As shown in (B), the solders 5, 6 of the electrode portions 3, 4 at both ends are melted, and the soldering of the electrode portions 3, 4 and the wiring patterns 9a, 9b is performed respectively. The light emitting diode is shown in FIG.
Lead terminals 26, 27, bonding wires 25, molding resin 2 protruding from the wiring board as in the conventional example described in
Since there is no 8, the size can be reduced to substantially the size of the element chip itself to achieve a reduction in size and thickness, the bonding wire does not break due to external force or thermal stress, and the external force applied to the chip during mounting is This is alleviated by the insulating resin coating layer 7, so that the reliability of the mounted light emitting diode is improved. Furthermore, the connection to the wiring pattern can be performed easily, quickly and with high precision, and there is no need to supply solder by screen printing of cream solder, etc., which reduces material and processing costs due to a reduction in the number of parts. Thus, the cost of the mounting operation can be reduced.

FIG. 2 shows a method for manufacturing the light emitting diode. In the light emitting diode, the P-type and N-type electrode portions 3 and 4 formed on the front and back surfaces of the light emitting diode in the state of the wafer 11 are covered with solder to form a solder coating layer 5,
After the formation of the solder coating layer 6, the N-side solder coating layer 6 is placed on the sheet 12 and attached, as shown in FIG. Next, as shown in FIG. 2 (B), the wafer 11 is diced vertically and horizontally to separate each chip. Further, as shown in FIG. 2 (C), the upper surface of each chip is masked with a sheet 13 and the side of each chip is cut. An insulating resin for protection is injected from the direction and cured to form the coating layer 7 on the side surface. Finally, as shown in FIG. 2 (D), if the sheet on the upper surface is removed, each chip is completed.

In the above-described manufacturing method, the coating of the P-type and N-type electrode portions 3 and 4 with the solder and the coating of the side surfaces with the insulating resin can be collectively performed in the state of the wafer 11, and the conventional wire bonding is performed. Since no resin mold is required, an extremely small and thin light emitting diode of a chip component type can be manufactured at low cost. In the above-described embodiment, the brazing material for coating the electrode portions 3 and 4 is solder. However, the brazing material may be another brazing material having a relatively low melting point. Further, the coating layer 7 on the side surface of the chip is not limited to the insulating resin of the present embodiment.
As long as it is an insulating material, it may be ceramic, glass, or the like, and may be provided only on one side facing the wiring substrate 8 instead of all four sides as in the present embodiment. Further, the masking sheet 13 on the upper surface of FIG. 2C may be a resist film that does not react with the insulating material of the coating layer 7. Alternatively, the masking sheet 13 may be omitted, and the insulating resin may be formed in the groove formed by dicing. To form the coating layer 7 on the side surface of the chip.

FIG. 3A is a perspective view showing a chip-part type light emitting diode according to an embodiment of the present invention. In this light emitting diode, the same two chips as described with reference to FIG. 1A are joined together by a solder coating layer 6 provided on the surface of the N-type electrode portion 4, and extend in a direction orthogonal to the PN junction surface. It is a long chip. Therefore, the same members as those described with reference to FIG.

In the light emitting diode, as shown in FIG. 3B, the chip is turned sideways, and the solder-coated electrode portions 5, 5 at both ends are connected to one and the other wiring patterns 9a, 9a on the wiring board 8. 9b, the central solder-coated electrode portions 4, 4 are placed vertically on the intermediate wiring pattern 9c, respectively, and both sides of the bottom portion coated with the insulating resin are temporarily fixed to the wiring board 8 with adhesives 10, 10. . Next, when the wiring board 8 is put into a reflow furnace heated to a temperature not lower than the melting point of the solder, as shown in FIG. The solder 6 between the electrodes 4 and 4 is melted, and these electrode portions and the wiring pattern 9 are melted.
a, 9b, 9c are soldered. Since the light emitting diode does not have the bonding wire 25 (see FIG. 6) and the mold resin 28 as in the conventional example similarly to the embodiment described with reference to FIG. 1, its size is reduced to substantially the size of the element chip itself. Reduces the size and thickness of the device, enables easy, quick, and accurate connection to the wiring pattern, and reduces the cost of mounting work by reducing material and processing costs due to the reduction in the number of parts. Can be.

FIG. 4 shows a method of manufacturing the light emitting diode described with reference to FIG. In the light-emitting diode, first, P and N-type electrode portions 3 and 4 on the front and back surfaces of the wafer are respectively coated with solder to provide solder coating layers 5 and 6.
After the wafers 11, 11 are manufactured, the two wafers are overlaid on each other with the solder coating layers 6, 6 and joined together in a reflow furnace or the like to form an integrated wafer 14, as shown in FIG. Apply the solder coating layer 5 on the side of sheet 1
Put on 2 and paste. Next, as shown in FIG. 3B, the wafer 14 is diced vertically and horizontally to separate each chip, and as shown in FIG. 3C, a resist layer 15 is formed on the upper surface of each chip by coating. Insulating resin for protection is injected from the side of the chip and hardened to form a coating layer 7 on the side. Finally, as shown in FIG. 3D, each chip is completed by removing the resist layer 15 on the upper surface. The circuit diagram of this light-emitting diode is as shown in FIG. 5A. For example, if one is red and the other is green, a two-color display light-emitting diode can be formed.

In the above manufacturing method, the coating of the electrode portions on the front and back surfaces of the two light emitting diode wafers with the solder, the overlapping joining of the two wafers, and the coating of the side surfaces of each chip separated by dicing with the insulating resin are performed. It can be performed in a batch in the state of a wafer, and furthermore, the conventional wire bonding and resin molding become unnecessary, and no solder is supplied to the joining of the electrode parts including the central electrode parts 4 and 4, so that it is extremely small and thin. Chip-part series-connected light-emitting diodes can be manufactured at low cost. If the above-described two-color display light-emitting diode is taken as an example, its length L, width W,
The height H is L = 0.5mm, W = 0.3mm, H = 0.3mm,
In comparison with the L, W, and H of the conventional example shown in FIG.
/ 3. In the above embodiment, the intermediate electrode portions 4 and 4 were joined by solder as a brazing material. However, when it is not necessary to connect the electrode portions 4 and 4 to the wiring pattern 9c, a conductive material is connected between the electrode portions. You may join with a material. As described in the embodiment of FIG. 2, the brazing material for coating the electrode portions at both ends is a low melting point brazing material other than the solder, and the coating layer on the side surface of the chip is an insulating material such as ceramic or glass. Coating may be applied to only one side. Also, the resist layer 15 on the upper surface
May be replaced with a masking sheet, these may be omitted, and an insulating material may be dropped on the dicing grooves to coat the chip side surfaces.

FIGS. 5B to 5E are circuit diagrams showing various modifications of the series-connected light emitting diodes produced by the manufacturing method described with reference to FIG. In these figures, of the connection points of the respective light emitting diode elements, those with the terminal indication are joined by a brazing material such as solder, but the other points need only be joined by a conductive material.

[0021]

As is apparent from the above description, the present invention
Chip-type light emitting diode manufactured by the manufacturing method, without the traditional bonding wires and a molding resin, compact and substantially reduce the size to a size of the element chip itself, Hakare is thinner, disconnection of bonding wires The reliability can be improved without the risk of soldering, and the connection work to the pattern on the wiring board can be performed easily, quickly and with high accuracy without the supply of solder, etc., coupled with the reduction in material and processing costs due to the reduction in the number of parts. What
The cost of the mounting operation can be reduced. further,
The external force applied to the chip during mounting is reduced by the coating layer of the insulating material on the side surface, so the reliability of the mounted light emitting diode is further improved, and the coating layer of the insulating material is used for soldering during soldering such as reflow. A short circuit between the two electrodes due to the brazing material can be prevented. Light emission of the present invention
According to the diode manufacturing method, such a light emitting diode
Coating with brazing material and insulation for manufacturing
Batch coating with material
Ultra-small and thin chip part type light emission
Diodes can be manufactured at low cost.

[0022]

[0023]

[0024]

[0025]

[Brief description of the drawings]

FIG. 1 is a perspective view showing a chip component type light emitting diode and a mounting structure thereof according to an embodiment of the present invention.

FIG. 2 is a view illustrating a method of manufacturing the light emitting diode of FIG. 1;

FIG. 3 is a perspective view showing a chip component type light emitting diode and a mounting structure thereof according to an embodiment of the present invention.

FIG. 4 is a view illustrating a method of manufacturing the light emitting diode of FIG. 3;

FIG. 5 is a circuit diagram showing various modifications of the light emitting diode of FIG. 3;

FIG. 6 is a plan view and a front view showing a conventional light emitting diode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 P-type layer 2 N-type layer 3 P-type electrode part 4 N-type electrode part 5, 6 Solder coating layer 7 Insulating resin coating layer 8 Wiring board 9a, 9b, 9c Wiring pattern 10 Adhesive 11, 14 Wafer 12, 13 sheet 15 resist layer

Continuation of the front page (56) References JP-A-57-49284 (JP, A) JP-A-52-52567 (JP, A) JP-A-60-46035 (JP, A) JP-A-5-338262 (JP) JP-A-6-177435 (JP, A) JP-A-49-108380 (JP, U) JP-A-54-86966 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB Name) H01L 33/00

Claims (2)

(57) [Claims] 1. A chip component type light emitting diode which can be directly mounted on a surface of a wiring board without using a bonding wire.
The method of manufacturing , the front and back of the light emitting diode in the wafer state,
Coating the negative electrode with brazing material
After forming the brazing layer, at least one brazing
The wafer is diced and separated.
And separate the sides of each chip separated by this dicing.
In other words, at least the side that is the mounting surface
A method for manufacturing a chip-part-type light-emitting diode , characterized by coating with an edge material . 2. Coating with said insulating material.
However, the surface opposite to the surface pasted on the sheet of each chip
The light emitting diode according to claim 1, wherein the light emitting diode is masked and coated with an insulating material .
Construction method .