JP2000049383A - Optoelectric conversion element and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optoelectric conversion element that has high utilization rate of materials and moreover can emit light of multiple colors. SOLUTION: A dimple formed on the surface of a substrate 21 for manufacturing is coated with electrodes 1 and 2, an optical element is mounted to the electrode 1, and the optical element and the other electrode 2 are bonded by a wire 4 before being sealed by a resin layer 24. The resin layer 24 and the substrate 21 for manufacturing are subjected to dicing for forming a piece including at least one set of optical element and wire, and only the substrate 21 for manufacturing is eliminated from the piece, thus exposing a package 5 due to the resin layer 24 and the electrodes 1 and 2 integrated in one piece with it on the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoelectric conversion element such as a semiconductor light emitting diode and a photodiode, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Light-emitting diodes (hereinafter referred to as "light-emitting diodes") are provided in image display sections of small electronic devices such as cellular phones and pagers.
Among them, a small-sized and thin surface-mounted chip-type LED is mainly used. Chip L
The ED is provided with a pair of electrodes that are electrically connected to each other on both the front and back surfaces of an insulating substrate. Bonding to the electrode is the basic configuration.

FIG. 7 is a schematic view showing an example of a conventional surface mount type chip LED. This chip LED includes a pair of electrodes 51 and 52 developed on both sides of an insulating substrate 50 on both front and back surfaces, and a compound semiconductor such as GaP or GaAlAs is mounted on a stage 51 a formed in connection with one electrode 51. The light emitting element 53 used is conductively mounted. Then, a bonding area 52a is formed on the other electrode 52, a wire 54 is bonded between the electrode 52 and the surface electrode of the light emitting element 53, and the light emitting element 53 and the wire 54 are sealed by a resin package 55. Have been.

In manufacturing such a chip LED, slits are cut in the substrate 50 in a wafer state at a pitch substantially equal to the interval between the electrodes 51 and 52, and these electrodes 51 and 52 are formed on both front and back surfaces of the substrate 50 by plating. Starting from the step of forming. After the mounting of the light emitting element 53 and the bonding of the wire 54, the package 55 is manufactured using a mold, and after dicing in the final step, a product having the illustrated shape is obtained.

However, the molding method of the package 55 is as follows.
Substrate 5 in wafer state on which electrodes 51 and 52 are formed
Since the mold is mounted on the surface of the mold 0 and the molten resin is injected, the substrate 50 needs a margin for mounting the mold. That is, as shown in the drawing, the portion where the package 55 is not formed is a hook for the mold, and almost the entirety of the electrodes 51 and 52 functions as a fixing jig for molding.

As described above, since the electrodes 51 and 52 disposed at both ends of the substrate 50 protrude from the package 55, the volume occupied by the entire plane area increases. Further, since the printed circuit board is mounted on the surface of the printed board including the board 50 itself, the thickness of the board 50 is increased by the thickness of the board 50.

[0007] On the other hand, a manufacturing method for making the package substantially the size of the chip LED has already been developed.
FIG. 8 shows a schematic vertical cross section of the chip LED obtained by this.
Shown in

In the figure, electrodes 57 and 58 are formed at two places on the bottom of a package 56 by plating, and a light emitting element 59 is mounted on one electrode 57 inside the package 56 in a conductive manner. Then, the light emitting element 59 and the other electrode 58 are bonded by a wire 60, and the electrodes 57, 58 are mounted on the printed wiring, so that the light emitting element 59 can be made conductive.

As described above, the electrode 5 is provided on the bottom of the package 56.
If the layers 7, 58 are formed directly, the bulk of the plane is reduced and the substrate itself is eliminated, so that a product with a small height can be obtained.

[0010]

The chip L shown in FIG.
In the method of manufacturing the ED, the package 56 is formed by die manufacturing as in the example of FIG. That is,
A copper alloy thin plate is used as a forming substrate, and electrodes 57,
58 is formed by plating, and after mounting the light emitting element 59 and bonding the wires 60, the package 56 is formed by die manufacturing, and the final step of removing the substrate by etching is performed.

However, in order to form the package 56 by molding, there is no other choice but to use a method in which each package 56 is separated into a mold shape along the outer periphery of the package 56. As a result, the mold occupies a space necessary for separating the package 56, and this space is widened with respect to the substrate. As a result, the product collection rate when the substrate is made into one unit decreases, and the productivity and product yield are affected. Exert.

In the case where the package 56 is formed by die manufacturing, only one type of chip LED can be obtained if the die is a type corresponding to only one including one light emitting element 59 as shown in FIG. . When a product is obtained by combining a plurality of light-emitting elements of a plurality of emission colors, another dedicated mold is required, which is not suitable for actual operation.

Further, the electrodes 57 and 58 are mounted on a printed circuit board and are conductively fixed by soldering. However, since these electrodes 57 and 58 do not extend to the side surfaces of the package 56, the fillet for soldering is confirmed. There is also a problem that it is difficult to remove.

The problem to be solved in the present invention is to provide a photoelectric conversion element which can be manufactured more economically by increasing the usage rate of materials and which can cope with multicolor light emission, and a method for manufacturing the same.

[0015]

According to the present invention, there is provided a method for manufacturing a photoelectric conversion element, comprising the steps of: forming a pattern of concave dimples for mounting an element and wire bonding on a surface of a manufacturing substrate; A step of coating an electrode on the periphery, a step of mounting an optical element on the dimple for mounting the optical element, and bonding a wire between the optical element and the dimple for wire bonding, and a step of bonding the surface of the manufacturing substrate. Encapsulating with a resin layer including the optical element and the wire, dicing the resin layer and a manufacturing substrate into a piece including at least one set of the optical element and the wire, and manufacturing from the piece. Exposing only the substrate for use to expose the surface of the package made of the resin layer and the electrodes integrated therewith. It is characterized in.

In this manufacturing method, since the resin layer in which the optical element and the wires are sealed is diced together with the manufacturing substrate, the degree of freedom in processing is improved as compared with the step of forming a mold when the package is formed by the resin layer. Also, the material usage rate is improved.

[0017]

DETAILED DESCRIPTION OF THE INVENTION The invention according to claim 1 is a step of patterning concave dimples for element mounting and wire bonding on the surface of a manufacturing substrate, and forming electrodes on the inner periphery of each of the dimples. A step of coating, a step of mounting an optical element on the dimple for mounting the optical element, and bonding a wire between the optical element and the dimple for wire bonding with a wire; And a step of sealing with a resin layer containing wires, a step of dicing the resin layer and the manufacturing substrate into a piece including at least one set of the optical element and the wire, and only the manufacturing substrate from the piece. Removing the package by the resin layer and exposing the electrode integrated with the package to the surface. A method for producing a photoelectric conversion element,
Dicing the resin layer encapsulating the optical element and the wire together with the manufacturing substrate enables the device to be integrated into a device that includes multiple optical elements, and also improves the material usage rate compared to package die manufacturing. It has the effect that it can be achieved.

According to a second aspect of the present invention, in the step of patterning concave dimples for element mounting and wire bonding on the surface of the manufacturing substrate, substantially one end of the piece is connected to the end of the piece following the dimple. 2. The method according to claim 1, further comprising the step of forming edge dimples of various depths.
This is a method for manufacturing a photoelectric conversion element as described above, and has an effect that an electrode can be formed up to a position facing a side surface of a package by forming an electrode even when the electrode is crossed over an edge dimple.

According to a third aspect of the present invention, the optical element is a light emitting diode, and the dimple for mounting the optical element is formed to a depth including a light emitting layer of the light emitting diode to be mounted. This is a method for manufacturing a photoelectric conversion element, and has an effect that light from a light emitting layer of a light emitting diode can be efficiently extracted using an electrode formed in a dimple as a reflection surface.

According to a fourth aspect of the present invention, there is provided a resin package, a pair of electrodes formed on a lower surface of the package, and an optical element sealed inside the package and electrically mounted on one of the electrodes. A wire bonded between the optical element and the other electrode and sealed inside the package, wherein the electrode has an edge extended to almost the same surface as the peripheral surface of the package on the outer surface. This is a photoelectric conversion element formed so as to face, and has an effect that it is easy to automatically recognize a soldering fillet at the time of mounting on a printed circuit board or the like by making the electrodes face the peripheral surface of the package.

According to a fifth aspect of the present invention, there is provided a resin package, a plurality of sets of electrodes formed on a lower surface of the package, and a package sealed inside the package and electrically connected to one electrode of each set of electrodes. An optical element to be mounted, and a wire bonded between the optical element and the other electrode and sealed inside the package, wherein the plurality of sets of electrodes are substantially the same as a peripheral surface of the package. A photoelectric conversion element that is formed with the edge extended to the surface facing the outer surface.One package has multiple optical elements and can respond to color light emission, and the electrode faces the peripheral surface of the package. This has an effect that the soldering fillet can be easily recognized automatically at the time of mounting on a printed circuit board or the like.

According to a sixth aspect of the invention, there is provided a resin package, a plurality of electrodes for mounting a device and a plurality of electrodes for bonding formed on a lower surface of the package, and the device which is sealed inside the package. A plurality of optical elements conductively mounted on the mounting electrodes, and a wire bonded between each of these optical elements and each electrode for bonding and sealed inside the package,
The element mounting and bonding electrodes are photoelectric conversion elements formed by facing the outer surface with an edge developed to almost the same surface as the peripheral surface of the package, and a plurality of optical elements are provided on the element mounting electrodes. By mounting the device, it is possible to cope with full-color light emission and the like with a small size, and it is possible to easily recognize the soldering fillet at the time of mounting on a printed board or the like by making the electrodes face the peripheral surface of the package.

According to a seventh aspect of the present invention, in the package, a spherical lens for condensing light is formed at a position corresponding to the optical element at a height below the surface of the package. 7. The photoelectric conversion element according to any one of items 1 to 6, which has an effect of improving the optical function by the light-collecting property of the lens and improving the degree of freedom of handling when mounting on a printed circuit board or the like.

According to an eighth aspect of the present invention, the optical element is a light emitting diode, and one electrode on the side on which the light emitting diode is conductively mounted has a concave cross section and the light emitting layer of the light emitting diode is buried. The photoelectric conversion element according to any one of claims 4 to 7, wherein the photoelectric conversion element is formed at a depth including the electrode, and has a function of efficiently extracting light from the light emitting layer of the light emitting diode using the electrode as a reflecting surface.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, taking a surface mount type LED as an example.

FIG. 1 is a schematic view showing the steps of the manufacturing method of the present invention, from the formation of an electrode on a substrate to the mounting of a light-emitting element, which will be described with reference to FIGS.

FIG. 1A: Dimples 21a and 21b are formed in a predetermined pattern by stamping or etching on the surface of a manufacturing substrate 21 which is formed, for example, by feeding a thin roll of copper alloy into a strip. One dimple 21
a is a portion where a light emitting element is mounted in a later step, and the other dimple 21b is a portion which becomes a wire bonding area, and each has the same depth.

FIG. 2B: A resist film 22 is applied on the surface of the manufacturing substrate 21. In this step, for example, an ultraviolet-curing resin (UV resin) is used as a resist material, and the resist film 22 is formed by dimples 21a and 21a by a roller transfer method.
It is formed uniformly on the surface except for 1b.

FIG. 5C: A mask 23 is formed on the back surface of the manufacturing substrate 21 by masking. In this step, the manufacturing substrate 21 is formed using a tape or an ultraviolet curable resin as a material.
Is entirely masked with a mask 23.

FIG. 4D: Electrodes 1 and 2 are formed on the dimples 21a and 21b by plating. The electrodes 1 and 2 are preferably formed as a three-layer plating of Au / Ni / Au, and the metallic luster is used as a light reflecting surface.

FIG. 5E: Resist film 22 and mask 23
Is removed by etching. Thereby, it is collected as the manufacturing substrate 21 in which the electrodes 1 and 2 are formed on the dimples 21a and 21b, respectively.

FIG. 5F: The light emitting element 3 is mounted on the electrode 1 of the dimple 21a, and the surface electrode 3a of the light emitting element 3 is mounted.
And the electrode 2 of the other dimple 21b is bonded by the wire 4.

By the steps described above, the electrodes 1 and 2 having a concave cross section are formed on the roll-shaped manufacturing substrate 21 by patterning.
A light emitting element 3 is mounted on each electrode 1. And
Through the process shown in FIG. 2, processing from resin sealing to dicing is performed. Each step will be described in order with reference to FIG.

FIG. 3A: A resin layer 24 such as an epoxy resin is molded over the entire surface of the manufacturing substrate 21. The resin layer 24 has a uniform thickness on the surface of the manufacturing substrate 21 and seals and packages all the light emitting elements 3 and the wires 4.

FIG. 4B: Before transferring the manufacturing substrate 21 on which the resin layer 24 is laminated to the dicing table,
The sheet 25 is adhered to the back surface of the substrate, and thereafter, dicing is performed by a dicer using the area including the electrodes 1 and 2 as one unit. In this dicing, only the resin layer 24 and the manufacturing substrate 21 are cut while leaving the sheet 25 as it is.

FIG. 3C: In the dicing step using a dicer, a pattern including one light-emitting element 3 as shown by a dashed line in the figure, and two adjacent ones as shown by a portion surrounded by a thick line. Dicing may be performed as a pattern including the light emitting element 3 described above. This gives 1
A product in which two light emitting elements 3 are provided in each chip LED can be obtained. By making the light emitting elements 3 emit different colors, a multicolor light emitting LED chip can be obtained.

FIG. 5D: The sheet 25 and the manufacturing substrate 21 laminated thereon are melted and removed by wet etching or the like to obtain an LED chip as a final product.

FIG. 3 is an enlarged vertical sectional view of the surface mount type LED chip obtained by the above steps.

The resin layer 24 diced together with the manufacturing substrate 21 is formed as a package 5 in which the light emitting element 3 and the wire 4 are sealed. Then, the electrodes 1 and 2 are conductively mounted according to the electrode pattern of the printed wiring board, so that the light emitting element 3 can be energized to emit light.

In the present invention, the resin layer 24 is
And then dicing is performed to obtain a surface-mounted LED including at least one light emitting element 3. Therefore, only the material corresponding to the cut width at the time of dicing is lost, and the loss ratio of the material can be reduced as compared with the conventional manufacturing method. In addition, since the package 5 includes the electrodes 1 and 2, the plane area can be reduced, and the height dimension can be shortened because there is no equivalent to a substrate, so that the thickness can be reduced.

FIG. 4 is a schematic perspective view showing a specific example of a configuration in which the plurality of light emitting elements 3 described in FIG.

In these examples, unlike the patterns of the dimples 21a and 21b provided on the manufacturing substrate 21 described above, the dimples corresponding to the mounting portions of the light emitting elements are arranged at the center, and the region sandwiching the dimples is provided. A dimple for wire bonding is formed as one pattern.

In the example of FIG. 4A, an element electrode 6a and bonding electrodes 6b and 6c are formed on the lower surface of the package 6 by plating, and two light emitting elements 7 and 8 are formed on the element electrode 6a. Conductive mounting. The wires 7b and 8b are bonded between the surface electrodes 7a and 8a of the light emitting elements 7 and 8 and the bonding electrodes 6b and 6c, respectively.

The example shown in FIG. 4B is substantially the same, and is an assembly in which the light emitting elements 7 and 8 are arranged in a line along with the bonding electrodes 6b and 6c. The same members as those in the example are indicated by common reference numerals.

FIG. 5 shows an example in which, instead of the structure shown in FIG. 3, the edges 1a and 2a are formed so that each of the electrodes 1 and 2 extends to a portion corresponding to the side surface of the package 5.

The manufacturing substrate 2 shown by a dashed line in FIG.
1 is a dimple 2 for mounting the element and bonding.
In addition to 1a and 21b, edge dimples 21c and 21d connected thereto are etched. Therefore, when the electrodes 1 and 2 are formed by the plating method, the edges 1a and 2a connected to the electrodes 1 and 2 are also integrally formed.

Since the edges 1a and 2a reach the surface of the package 5, when they are mounted and fixed on the printed circuit board by soldering, the optical automatic recognition of the edges 1a and 2a facing the surface is more reliably performed. . Therefore,
In addition to stabilizing the mounting of the LED, the solder fillet is formed between the edges 1a and 2a and the printed circuit board, so that a more robust assembly can be achieved.

FIG. 6 shows the example of FIG. 5 in which a lens 5a is formed on a portion of the package 5 corresponding to the light emitting element 3. The lens 5a is formed in a hemispherical shape, and its axis is aligned with the optical axis of the light emitting element 3. The upper end of the lens 5a does not protrude from the upper surface of the package 5.

When such a lens 5a is provided, light from the light emitting element 3 is condensed, so that light emission luminance is improved.
In addition, when mounting on a printed circuit board, handling is performed in which the upper surface of the package 5 is sucked by the vacuum nozzle, but since the lens 5a does not protrude from the upper surface, it does not interfere with the nozzle, which hinders mounting. Nor.

In each of the examples shown in FIGS. 3 to 6, the light emitting element 3 using the light emitting diode has its pn
The height relationship is such that the light emitting layer in the junction region is included in the concave electrode 1. As a result, the electrode 1 has a high light reflectance A
If u or the like is set, light from the light emitting layer can be effectively reflected in the light emitting direction, so that the light emission luminance can be improved.

In the above example, the surface mount type LED chip has been described, but an IC such as a photodiode may be used.

[0052]

According to the present invention, a chip is obtained by cutting a resin layer and a manufacturing substrate by dicing instead of manufacturing a package by a mold device. Effective utilization of the material is also improved.

By changing the dicing pattern, it is possible to obtain a photoelectric conversion element in which a combination of a plurality of optical elements is housed in one package. Particularly, when a light emitting diode is used, it greatly contributes to full color light emission display. it can.

Further, in the case of forming an edge on an electrode,
Since the soldering fillet is automatically recognized by the optical system at the time of mounting on a printed circuit board or the like, the mountability is greatly improved and the product yield is also improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing steps from electrode formation to light emitting element mounting in a manufacturing method of the present invention.

FIG. 2 is a schematic diagram showing a process up to the completion of a product following the process of FIG. 1;

FIG. 3 is an enlarged sectional view of a chip LED obtained in a final step of FIG. 2;

FIG. 4 is a perspective view showing an example of a chip LED incorporating two light emitting elements.

FIG. 5 is a schematic longitudinal sectional view showing a chip LED provided with edges on electrodes together with a substrate for manufacturing the chip LED.

FIG. 6 is a schematic longitudinal sectional view showing an example of a chip LED in which a lens is provided in a package.

FIG. 7 is a schematic perspective view of a conventional surface mount type chip LED.

FIG. 8 is a longitudinal sectional view showing a conventional example in which electrodes are formed on the lower surface of a package.

[Explanation of symbols]

 Reference Signs List 1 electrode 1a edge 2 electrode 2a edge 3 light emitting element 3a surface electrode 4 wire 5 package 6 package 6a element electrode 6b, 6c bonding electrode 7,8 light emitting element 7a, 8a surface electrode 7b, 8b wire 21 manufacturing substrate 21a, 21b dimple 22 resist film 23 mask 24 resin layer 25 sheet

Claims (8)

[Claims] 1. A step of patterning concave dimples for mounting elements and wire bonding on a surface of a manufacturing substrate, a step of coating an electrode on an inner periphery of each of the dimples, A step of mounting an optical element on the dimple and bonding the optical element and the dimple for wire bonding with a wire; and sealing a surface of the manufacturing substrate with a resin layer including the optical element and the wire. Dicing the resin layer and the manufacturing substrate into a piece including at least one set of the optical element and the wire; and removing only the manufacturing substrate from the piece to form a package using the resin layer. Exposing the integrated electrode to the surface. 2. In the step of patterning concave dimples for mounting elements and wire bonding on the surface of the substrate for manufacturing, an edge having a substantially uniform depth extending to an end of the piece following the dimples. The method for manufacturing a photoelectric conversion element according to claim 1, further comprising a step of forming a dimple. 3. The method according to claim 1, wherein the optical element is a light emitting diode, and the dimple for mounting the optical element is formed to a depth including a light emitting layer of the light emitting diode to be mounted. 4. A resin package, a pair of electrodes formed on a lower surface of the package, and an optical element sealed inside the package and conductively mounted on one of the electrodes.
A wire bonded between the optical element and the other electrode and sealed inside the package,
A photoelectric conversion element, wherein the electrode is formed with an edge developed to substantially the same surface as a peripheral surface of the package facing an outer surface. 5. A resin package, a plurality of sets of electrodes formed on the lower surface of the package, and an optical element sealed inside the package and electrically mounted on one of the electrodes of each set of electrodes. A wire bonded between the optical element and the other electrode and sealed inside the package, wherein the plurality of sets of electrodes have edges developed to approximately the same surface as the peripheral surface of the package. A photoelectric conversion element formed facing the outer surface. 6. A resin package, an element mounting electrode and a plurality of bonding electrodes formed on the lower surface of the package, and electrically mounted on the element mounting electrode sealed inside the package. A plurality of optical elements, and a wire bonded between each of these optical elements and each of the bonding electrodes and sealed inside the package. Is a photoelectric conversion element formed such that an edge developed to almost the same surface as the peripheral surface of the package faces the outer surface. 7. The package according to claim 4, wherein a spherical lens for light collection is formed at a position corresponding to the optical element so as to have a height equal to or lower than the surface of the package. Photoelectric conversion element. 8. The optical element is a light emitting diode, and one electrode on the side on which the light emitting diode is conductively mounted is formed to have a concave cross section and a depth including a light emitting layer of the light emitting diode in a buried state. The photoelectric conversion element according to claim 4.