JPH1051034A - Surface-mount electronic component, its manufacture, method for mounting the component on circuit board, and circuit board mounting the component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable surface mount on a circuit board, without deteriorating performance of an electronic component by solder reflow, by covering at least the side surface or the bottom surface of a transparent resin package with resin whose thermal conductivity is lower than that of the transparent resin package. SOLUTION: In an LED device 1, the bottom surface of a transparent resin package 10 is covered with resin whose thermal conductivity is lower than that of the package. Thereby the bottom surface of the transparent resin package 10 is thermally protected. When the LED device 1 is heated in a reflow furnace for surface mount on a circuit board 6, the amount of heat applied from the bottom surface of the transparent resin package 10 can be reduced as compared with the conventional case. Thereby thermal shrinkage of the transparent resin package 10 can be reduced, so that surface mount on the circuit board is enabled without deteriorating performance of an electronic component by solder reflow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-mounted electronic component of an optical system mounted on a circuit board, a method of manufacturing the same, a method of mounting the same on a circuit board, and a circuit board on which the same is mounted.

[0002]

2. Description of the Related Art For example, as a surface mount type electronic component of an optical system, there is an LED light emitting device 1 as shown in FIG. This LED light-emitting device 1 includes a transparent resin package 10
The internal leads 30 and 40 sealed in the inside, and connected to the internal leads 30 and 40,
And first and second leads 3 and 4 having external leads 31 and 41 extending from the side surfaces of the first and second leads. Horizontal portions 31a, 41a are formed at the tips of the external leads 31, 41, respectively. The LED chip 5 is bonded to the tip of the internal lead 40 of the second lead 4, and the LED chip 5 is connected to the tip of the internal lead 30 of the first lead 3 using the wire 6. Have been. Such an LED light emitting device 1 is used by being mounted on a circuit board on which a wiring pattern is formed.

In general, electronic components are mounted on a circuit board by soldering. In particular, the above LED
A solder reflow method is used for soldering in a so-called surface-mount type electronic component in which horizontal portions 31a and 41a are formed at the tips of the external leads 31 and 41, respectively, like the light emitting device 1. For mounting electronic components by the solder reflow method, cream solder is printed in advance on a circuit board, and horizontal portions 31a and 41a of external leads of the electronic components are placed so as to correspond to the printed portion. This is performed by connecting the leads 3 and 4 and the wiring pattern of the circuit board in a conductive state with the solder melted by the heat of the heating furnace (reflow furnace).

[0004]

Usually, the temperature of a furnace used in the above solder reflow method is as high as about 260 ° C., so that the resin package formed of epoxy resin or the like or the inside of the resin package is formed. A considerable amount of heat will be applied to the conducting leads.
Therefore, the resin package and the lead undergo thermal contraction, and the thermal contraction causes the contact surface between the resin package and the lead or the light emitting element chip or the light receiving element chip bonded to the resin package and the lead. In some cases, the contact surface with the chip may peel off.

Further, there is a problem that a chip such as a light emitting element chip or a light receiving element chip bonded to the lead is subjected to stress due to the heat shrinkage of the resin package and the output of the chip is reduced. May also occur. Therefore, for example, in an electronic component such as an LED light emitting device in which a light emitting element chip such as an LED chip is encapsulated, the LED light emitting device emits light with a desired luminance when a voltage is applied to the LED light emitting device. There may be situations where they do not.

In view of this, a method has been conceived in which a filler is inserted into a transparent epoxy resin or the like to reduce the thermal conductivity of the resin, thereby suppressing thermal shrinkage and packaging the light emitting element chip or the light receiving chip in a resin. However, the insertion of the filler changes the refractive index of the resin with respect to the light. Therefore, in an electronic component of an optical system, for example, an electronic component in which a light emitting element chip and a light receiving element chip are sealed, the appropriate means is used. Hard to say.

That is, in the prior art, an optical electronic component, such as a light emitting element chip or a light receiving element chip, which can maintain the product performance even at a high temperature in a reflow furnace and can be surface-mounted, is sealed therein. It was difficult to provide such electronic components.

The present invention was conceived in view of the above circumstances, and when electronic components are mounted on a circuit board by a solder reflow technique, the performance of the electronic components may deteriorate. It is an object of the present invention to provide a surface-mounted electronic component of an optical system that can be surface-mounted on a circuit board without any problem, a method of manufacturing the same, a method of mounting the same on a circuit board, and a circuit board on which the same is mounted. .

[0009]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

That is, according to the first aspect of the present invention, a light emitting element chip or a light receiving element chip is sealed in a transparent resin package, and is electrically connected to the light emitting element chip or the light receiving element chip inside the transparent resin package. A surface-mounted electronic component in which the lead is extended outside so as to have a horizontal portion, wherein at least a side surface or a bottom surface of the transparent resin package has a lower thermal conductivity than the transparent resin package. Provided is a surface mount electronic component, which is characterized by being coated with a resin.

In a preferred embodiment, the resin that covers at least the side surface or the bottom surface of the transparent resin package is an epoxy resin containing filler or polyphenylene sulfide.

In such a surface-mounted electronic component, at least a side surface or a bottom surface of the transparent resin package is coated with a resin having a lower thermal conductivity than the transparent resin package, for example, a filler-containing epoxy resin or polyphenylene sulfide, A coating layer is formed on the surface of the transparent resin package. That is, the leads can be extended to the outside of the surface mount electronic component via the coating layer having a lower thermal conductivity than the transparent resin package.

Therefore, when the above surface mount type electronic component is mounted on a circuit board by a solder reflow technique,
Even if the part of the lead that extends to the outside of the surface-mounted electronic component is heated by the heat of the reflow furnace, the thermal conductivity of the coating layer formed to cover the surface of the surface-mounted electronic component is reduced. The amount of heat transmitted through the leads to a portion of the lead sealed in the transparent resin package and a chip such as a light emitting element chip or a light receiving element chip bonded to this portion because the lead is lower than the transparent resin package. Can be reduced. further,
The portion of the transparent resin package where the coating layer is formed is
Heat is not directly applied to the transparent resin package, and furthermore, heat is applied via a resin having a lower thermal conductivity than the transparent resin package. Can be reduced.

As described above, the surface-mounted electronic component according to the present invention can reduce the heat applied to the transparent resin package and the portions of the leads sealed in the transparent resin package. Thermal shrinkage of the resin package and the leads can be suppressed as compared with the related art. Therefore, a contact surface between the transparent resin package and the lead or a contact surface between the transparent resin package and a chip such as a light emitting element chip and a light receiving element chip are peeled off due to thermal shrinkage of the transparent resin package and the lead. Can be avoided.

[0015] Further, by forming a coating layer with a resin having a lower thermal conductivity than the transparent resin package on all surface portions of the transparent resin package that are not directly involved in light emission or light reception, heat is prevented from being applied in a reflow furnace. The transparent resin package can be protected. Thus, the heat applied to the transparent resin package can be reduced as compared with the related art, so that the heat shrinkage of the transparent resin package can be reduced. Therefore, it is possible to avoid such a problem that a stress is applied to a chip such as a light emitting element bonded to the lead due to the heat shrinkage of the transparent resin package and the output of the chip is reduced. That is, in a surface-mounted electronic component in which a light emitting element chip or a light receiving element chip is sealed, when the voltage is applied to the electronic component, the electronic component can emit light with desired luminance.

As a result, the surface-mounted electronic component according to the present invention can maintain product performance even at a high temperature in a reflow furnace, and can be surface-mounted on a circuit board.

According to the second aspect of the present invention, a light emitting element chip or a light receiving element chip is sealed in a transparent resin package, and is electrically connected to the light emitting element chip or the light receiving element chip inside the transparent resin package. A method for manufacturing a surface-mounted electronic component in which a lead is extended to the outside so as to have a horizontal portion, using a manufacturing required frame formed to include the lead, A chip bonding step of bonding an element chip or a light receiving element chip to a lead formed on the frame requiring manufacturing; and a step of bonding the light emitting element chip or the light receiving element chip to a lead other than the lead to which the light emitting element chip or the light receiving element chip is bonded. Connecting the light emitting element chip or the light receiving element chip in a transparent resin. A sealing step, a coating step of coating at least a side surface or a bottom surface of the transparent resin package with a resin having a lower thermal conductivity than the transparent resin package, and a forming step of forming a horizontal portion at an end of the lead. And a method for manufacturing a surface-mounted electronic component.

Needless to say, the surface-mounted electronic component manufactured by such a manufacturing method can enjoy the effects of the surface-mounted electronic component described above.

According to a third aspect of the present invention, a light emitting element chip or a light receiving element chip is sealed in a transparent resin package, and is electrically connected to the light emitting element chip or the light receiving element chip inside the transparent resin package. The surface mounting wherein the leads are extended outside so as to have a horizontal portion, and at least a side surface or a bottom surface of the transparent resin package is coated with a resin having a lower thermal conductivity than the transparent resin package. A method for mounting a die-type electronic component on a circuit board, the step of applying cream solder on the circuit board, and the step of placing the horizontal portion in an area of the circuit board on which cream solder is applied. And a step of heating and dissolving the cream solder while the resin package is placed on the circuit board. Characterized Rukoto, mounting method of the surface mount electronic device is provided.

According to a fourth aspect of the present invention, a light emitting element chip or a light receiving element chip is sealed in a transparent resin package, and is electrically connected to the light emitting element chip or the light receiving element chip inside the transparent resin package. The surface mounting wherein the leads are extended outside so as to have a horizontal portion, and at least a side surface or a bottom surface of the transparent resin package is coated with a resin having a lower thermal conductivity than the transparent resin package. Provided is a circuit board on which a surface-mounted electronic component is mounted, wherein the circuit board has a mounted electronic component.

[0021] Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a perspective view of an LED light emitting device 1 as a surface mount type electronic component according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG. It is.
The LED light emitting device 1 has internal leads 30 and 40 sealed in a transparent resin package 10 molded of epoxy resin or the like, and is connected to the internal leads 30 and 40 and extends from a side surface of the transparent resin package 10. And first and second leads 3 and 4 provided with external leads 31 and 41, respectively. Horizontal portions 31a, 4 for surface-mounting the LED light emitting device 1 on a wiring pattern formed on the circuit board 6 are provided at the tips of the external leads 31, 41.
1a are formed, and the inner leads 4 of the second leads 4 are formed.
The tip of the LED chip 5 is wider than the other parts,
Is formed in a chip bonding portion 42 to be bonded.

The chip bonding section 42 has an LE
The D chip 5 is bonded, and the upper electrode 50 formed on the upper surface of the LED chip 5 is connected to the first lead 3.
Are connected to the tip of the internal lead 30 using the wire 6. Thus, the LED chip 5 is configured to be electrically connected to the outside of the LED chip 5. A convex spherical lens portion 11 is formed on the upper surface of the transparent resin package 10 so that a voltage is applied to the LED chip 5 and the LED chip 5 emits light when the LED chip 5 emits light. ing.

Further, the bottom surface of the transparent resin package 10 is covered with a resin having a lower thermal conductivity than the transparent resin package 10, for example, a resin such as a filler-containing epoxy resin or polyphenylene sulfide (PPS). Are formed.

Next, a method for manufacturing the LED light-emitting device 1 having the above-described structure will be described with reference to FIG.

FIG. 3 shows a manufacturing frame 7 for manufacturing the LED light emitting device 1 described above. The first lead 3 has a first lead terminal 3a integrally extending downward and connected to one side frame portion 7a, and a support frame 3b integrally extending upward and extending to the other side. It is connected to the frame part 7b. A second lead terminal 4a extends downward and integrally with the second lead 4 substantially parallel to the first lead 3, and is connected to one side frame portion 7a. And is connected to the other side frame portion 7b. The units shown in FIG. 3 are continuous in the left-right direction. The manufacturing frame 7 can be obtained by punching a conductive metal plate.

First, the LED chip 5 is bonded to the chip bonding portion 42 on which the second lead 4 is formed. Then, the upper surface electrode 50 formed on the upper surface of the LED chip 5 and the tip of the first lead are connected by a conductive wire 6.

Subsequently, the transparent resin package 1 is wrapped around an area surrounded by a virtual line shown in FIG.
0 is formed using a mold forming apparatus. Specifically, the above-described manufacturing frame 7 is installed at a predetermined position of a lower mold formed in a predetermined mold, the upper mold is fixed to the lower mold, the mold is clamped, and a resin injection operation is performed to perform transparent operation. The resin package 10 is formed. As a material of the transparent resin package 10, an epoxy resin or the like is employed.

Next, the bottom surface of the transparent resin package 10 is coated with a resin having a lower thermal conductivity than the resin used for the transparent resin package 10 to form a coating layer 2. This step is also performed by using a mold molding apparatus in the same manner as in the molding of the transparent resin package 10.

The support frames 3b, 4b
Is cut along the outer surface of the transparent resin package 10, and the terminal leads 3a, 3b are cut along the line indicated by the symbol A in FIG. Further, external leads 3 extending outside from the side surfaces of the transparent resin package 10 are provided.
The LED light emitting device 1 as shown in FIG. 1 is formed by performing forming processing so as to form the horizontal portions 31a and 41a at the tip portions of the first and the first portions 41.

The LED light emitting device 1 thus formed is surface-mounted on the circuit board 6 by a solder reflow method. Specifically, cream solder is printed on the circuit board 6 in advance, and the LE
The horizontal portions 31a and 41a of the external leads of the D light emitting device 1 are placed, and the first and second leads 3 and 4 and the wiring pattern of the circuit board 6 are soldered by solder melted by the heat of a heating furnace (reflow furnace). Are connected in a conductive state.

The LED light emitting device 1 according to the present embodiment has a transparent resin package 10
Because it is covered with a resin with lower thermal conductivity than
The bottom surface of the transparent resin package 10 is thermally protected, and when the LED light emitting device 1 is heated in the reflow furnace for surface mounting on the circuit board 6, the bottom surface of the transparent resin package 10 is The amount of heat added from the heat can be reduced as compared with the related art. Therefore, thermal shrinkage of the transparent resin package 10 due to heating can be reduced. As a result, stress is applied to the LED chip 5 bonded to the first and second leads 3 and 4 due to the heat shrinkage of the transparent resin package 10, and the output of the LED chip 5 is reduced. Can be avoided. That is, when a voltage is applied to the LED light emitting device 1 configured as described above, the LED light emitting device 1 can emit light with a desired luminance.

FIG. 4 is a perspective view of an LED light-emitting device 1 as a surface-mounted electronic component according to a second embodiment of the present invention, and FIG. 5 is a sectional view taken along line VV of FIG. It is.
In this embodiment, the basic configuration is the same as that of the above-described first embodiment.
Not only the bottom but also the side of the transparent resin package 10
It differs from the first embodiment in that it is covered with a resin having a lower thermal conductivity. Such an LED light emitting device 1
It can be manufactured through substantially the same steps as the manufacturing method of the first embodiment described above.

The LED light emitting device 1 in this embodiment is
Since the bottom surface of the transparent resin package 10 is covered with a resin having a lower thermal conductivity than the transparent resin package 10, the same effects as those of the first embodiment can be obtained. Furthermore, in this embodiment, since the side surface of the resin package 10 is also covered with a resin having a lower thermal conductivity than the transparent resin package 10, the portion of the transparent resin package 10 where the coating layer 2 is formed is Since heat is not directly applied to the transparent resin package 10 and heat is applied via a resin having a lower thermal conductivity than that of the transparent resin package 10, the transparent resin package 10 The amount of heat applied to the can be reduced. Further, in the LED light emitting device 1 in which the external leads 31 and 41 extend from the side surface of the LED light emitting device 1 as in the present embodiment, it is assumed that the external leads 31 and 41 are heated by the heat of the reflow furnace. Also, since the thermal conductivity of the coating layer 2 is lower than that of the transparent resin package 10, the chips of the internal leads 30 and 40 sealed in the transparent resin package 10 and the internal leads 40 of the second lead are used. Bonding part 4
The amount of heat transmitted to the LED chip 5 bonded to the LED chip 2 via the second lead 4 can be reduced.

As described above, in the LED light emitting device 1 according to the present embodiment, the amount of heat applied to the transparent resin package 10 and the internal leads 30 and 40 can be reduced. Heat shrinkage of 30, 40 can be suppressed as compared with the related art. Therefore, due to the heat shrinkage of the transparent resin package 10 and the internal leads 30 and 40, the contact surface between the transparent resin package 10 and the internal leads 30 and 40 and the contact between the transparent resin package 10 and the LED chip 5 A situation in which the contact surface is peeled off can be avoided, and the effect of the first embodiment can be further enhanced.

FIG. 6 is a perspective view of an LED light-emitting device 1 as a surface-mounted electronic component according to a third embodiment of the present invention, and FIG. 7 is a sectional view taken along line VII-VI of FIG. It is. In the present embodiment, the basic configuration is the same as that of the above-described second embodiment, but not only the bottom and side surfaces of the transparent resin package 10 but also the upper surface of the resin package 10 is larger than that of the transparent resin package 10. Also, the second embodiment differs from the second embodiment in that the convex lens portion 11 is covered with a resin having a low thermal conductivity so as to be exposed. Such an LED light emitting device 1 can be manufactured through substantially the same steps as the manufacturing methods of the first and second embodiments described above.

In such an LED light emitting device 1,
Since the upper surface of the resin package 10 is also covered with a resin having a lower thermal conductivity than the transparent resin package 10, the amount of heat applied from the upper surface of the transparent resin package 10 can be reduced as compared with the related art. The effect of the second embodiment can be further enhanced.

In this embodiment, the first and second leads both extend from one side surface of the LED light emitting device, but the first and second leads extend from the bottom surface. The present invention can also be applied to an object or an object extending from an opposing side surface.

In addition to the LED light emitting device having two leads extending from the LED light emitting device as in this embodiment,
The present invention is applicable to a device in which many leads extend from the D light emitting device.

The light emitting element chip bonded to the chip bonding portion of the second lead is an LED.
It is not limited to chips. Further, a surface-mounted electronic component in which a light receiving element chip is bonded to a chip bonding portion of the second lead as a chip is also applicable to the present invention. Further, the chip bonding portion formed on the second lead is optional and is not always necessary.

Further, a resin having a low coefficient of thermal expansion may be used as a resin for covering the transparent resin package. Also in this case, it is possible to reduce the heat transmitted to the surface of the transparent resin package and the heat transmitted to the inside of the transparent resin package and the chips such as the light emitting element chip and the light receiving element chip via the leads. That is,
The thermal expansion of the transparent resin package can be reduced, and the same effects as those of the above embodiments can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of an LED light emitting device as a surface mount electronic component according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a front view of a manufacturing frame.

FIG. 4 is a perspective view of an LED light emitting device as a surface mount electronic component according to a second embodiment of the present invention.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a perspective view of an LED light emitting device as a surface mount electronic component according to a third embodiment of the present invention.

FIG. 7 is a sectional view taken along line VII-VII in FIG. 6;

FIG. 8 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 LED light emitting device (surface mounted electronic component) 2 coating layer 3 first lead 4 second lead 5 LED chip (light emitting element chip) 6 wire 10 transparent resin package

Continued on the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical display location H01L 23/31 H01L 31/02 B 31/02

Claims (5)

[Claims] 1. A light emitting element chip or a light receiving element chip is sealed in a transparent resin package, and a lead electrically connected to the light emitting element chip or the light receiving element chip has a horizontal portion inside the transparent resin package. Wherein the at least one side surface or the bottom surface of the transparent resin package is covered with a resin having a lower thermal conductivity than that of the transparent resin package. , Surface mount electronic components. 2. The resin covering at least the side surface or the bottom surface of the transparent resin package is a filler-containing epoxy resin or polyphenylene sulfide.
The surface-mounted electronic component according to claim 1. 3. A light emitting element chip or a light receiving element chip is sealed in a transparent resin package, and a lead electrically connected to the light emitting element chip or the light receiving element chip has a horizontal portion inside the transparent resin package. A method for manufacturing a surface-mounted electronic component that is extended to the outside using a manufacturing frame formed so as to include the lead, wherein the light-emitting element chip or the light-receiving element chip is manufactured by the method. A chip bonding step of bonding to a lead formed on a frame for use; a step of connecting the light emitting element chip or the light receiving element chip to a lead other than the lead to which the light emitting element chip or the light receiving element chip is bonded; Encapsulating the chip or the light receiving element chip in a transparent resin; A coating step of coating at least a side surface or a bottom surface of the resin package with a resin having a lower thermal conductivity than the transparent resin package, and a forming step of forming a horizontal portion at an end of the lead. , Surface mount type electronic parts manufacturing method. 4. A light emitting element chip or a light receiving element chip is sealed in a transparent resin package, and a lead electrically connected to the light emitting element chip or the light receiving element chip has a horizontal portion inside the transparent resin package. A surface-mount type electronic component is mounted on a circuit board, and the resin has a lower thermal conductivity than the transparent resin package on at least a side surface or a bottom surface of the transparent resin package. A step of applying cream solder on the circuit board; a step of placing the horizontal portion in an area of the circuit board on which cream solder is applied; and a step of applying the resin package to the circuit board. Heating and melting the cream solder in a state where is placed, Implementation method of the type electronic components. 5. A light emitting element chip or a light receiving element chip is sealed in a transparent resin package, and a lead electrically connected to the light emitting element chip or the light receiving element chip has a horizontal portion inside the transparent resin package. And a surface-mounted electronic component that is covered with a resin having a lower thermal conductivity than the transparent resin package is mounted on at least a side surface or a bottom surface of the transparent resin package. A circuit board, characterized by: