KR20080056835A - Fabrication method of epoxy molding compound tablet and the epoxy molding compound tablet thereby and fabrication method of white emitting device thereby - Google Patents

Abstract

A method for generating an EMC(epoxy molding compound) tablet is provided to avoid an increase of white scattering caused by phosphor particles not more than 5 mum by performing first and second ball milling processes in generating an EMC tablet to be used in a transfer molding process. Epoxy powder of a powder type is ground(S11). EMC in which the ground epoxy powder is mixed with phosphor powder is generated(S12). The EMC is transformed into an EMC tablet(S13). The ground process can include the following steps. The epoxy powder of the powder type is put into a jar and is ground by a ball milling process. The process for generating the EMC can include the following steps. The epoxy powder ground by the ball milling process and the phosphor powder are put into a jar and are mixed by a ball milling process.

Description

FIELD OF THE INVENTION EPOXY MOLDING COMPOUND TABLET AND THE EPOXY MOLDING COMPOUND TABLET THEREBY AND FABRICATION METHOD OF WHITE EMITTING DEVICE THEREBY}

1 is a process chart of manufacturing a white light emitting diode by performing a transfer molding using an epoxy molding compound tablet containing a phosphor according to an embodiment of the present invention.

Figure 2 is a process for producing an epoxy molding compound tablet containing a phosphor according to an embodiment of the present invention.

3 to 5 are graphs for each PCB of a white LED according to a comparative example manufactured using an epoxy-molded compound tablet produced in a state where ball milling was performed at 80 rpm for 80 minutes in a state where epoxy powder and phosphor were put together.

6 to 8 are comparative graphs showing the improvement of the white scatter for each PCB manufactured by performing a transfer molding using an epoxy molding compound tablet containing a phosphor according to an embodiment of the present invention for each PCB.

The present invention relates to a method of manufacturing a white light emitting diode, and more particularly, to produce a white light emitting diode through transfer molding, an epoxy molding compound (epoxy) which improves a phenomenon in which white coordinate dispersion is caused by fine particles of a phosphor. molding compound (EMC) tablet production method and epoxy molding compound tablet produced by the same and a method for manufacturing a white light emitting device using the same.

In general, the light emitting diode has excellent monochromatic peak wavelength, excellent light efficiency, and miniaturization, and thus is widely used as various display devices and light sources. In particular, white light emitting diodes have been actively utilized as high-power, high-efficiency light sources that can replace the backlight of lighting devices or display devices.

As a method of implementing the white light emitting diode, a wavelength conversion method of converting white light into a white light by applying a phosphor to a blue or ultraviolet light emitting diode is mainly used.

The method of applying a phosphor to a blue or ultraviolet light emitting diode includes a method using a dispensing process using a liquid resin including a phosphor and a method using transfer molding.

Since the dispensing process uses a liquid resin, there has been a problem that the phosphor powder is precipitated in the liquid resin while the liquid resin is cured.

On the other hand, transfer molding is a method of manufacturing an epoxy molding compound tablet by mixing a phosphor in a powder type epoxy powder, and molding the epoxy molding compound tablet on a blue LED.

Since the curing time is relatively shortened by the transfer molding process, the degradation of the light conversion efficiency due to the precipitation of the phosphor powder can be prevented, and at the same time, the mass productivity can be improved.

However, the white coordinate dispersion appears long in a white LED conventionally manufactured by a transfer molding method.

In addition, since the molding epoxy is cured in a short time, it is difficult to change the distribution of the phosphor during epoxy curing. Due to the nature of transfer molding, an epoxy molding compound tablet can be used to mold several sheets at a time, which may cause variations between PCBs. There is a problem that the overall dispersion is large due to the deviation between the PCB.

Due to these problems, in spite of the advantages of the transfer molding process, the partially produced white light emitting diodes still emit light in the actual white light emitting diodes, and it has been difficult to manufacture light emitting diodes having excellent light conversion efficiency.

An object of the present invention is to improve the concentration of the target coordinates by reducing the dispersion of the white coordinates when performing the transfer molding on the chip LED.

According to an aspect of the present invention for achieving the above technical problem, by the method of producing an epoxy molding compound tablet containing a phosphor for the transfer molding of the light emitting device, the step of pulverizing the powder type epoxy powder, and the pulverized epoxy It provides an epoxy molding compound tablet production method comprising the step of generating an epoxy molding compound (EMC) mixed with a powder and a phosphor powder, and producing the epoxy molding compound into an epoxy molding compound tablet.

The pulverizing step includes the step of pulverizing the powder-type epoxy powder in a jar and ball milling, wherein the epoxy molding compound generating step is the epoxy powder and the phosphor powder pulverized through the ball milling It may include a process for mixing through ball milling in a jar (jar).

Preferably the ball milling process for the grinding is performed for 20 to 40 minutes at 100 to 130rpm, the ball milling process for the mixing may be performed for 20 to 40 minutes at 40 to 80rpm.

According to another aspect of the present invention, in the method of manufacturing a white light emitting device by transfer molding the epoxy molding compound in which the phosphor is mixed on the LED chip, producing an epoxy molding compound in which the phosphor powder and the powder type epoxy powder is mixed And transfer molding the PCB substrate on which the LED chip is wire-bonded to the epoxy molding compound, and separating the PCB substrate into individual white light emitting devices through a sawing and barrel process. The generating of the epoxy molding compound may include: pulverizing a powder type epoxy powder, generating an epoxy molding compound (EMC) in which the pulverized epoxy powder and the phosphor powder are mixed, and the epoxy molding Producing the compound into an epoxy molding compound tablet.

The pulverizing step includes the step of pulverizing the powder-type epoxy powder in a jar and pulverizing through ball milling for 20 to 40 minutes at 100 to 130 rpm, and the epoxy molding compound generating step is pulverizing through the ball milling. The epoxy powder and the phosphor powder may be added to the jar and mixed by ball milling at 40 to 80 rpm for 20 to 40 minutes.

According to still another aspect of the present invention, an epoxy molding compound tablet including phosphor for transfer molding of a light emitting device is mixed with a powder-type epoxy powder pulverized by a pulverization process and an epoxy powder pulverized by the pulverization process. And a phosphor powder, wherein the phosphor powder and the epoxy powder are mixed to provide an epoxy molding compound tablet formed into a tablet.

The epoxy powder may be pulverized through primary ball milling, and the phosphor powder may be mixed through secondary ball milling to the epoxy powder pulverized through the primary ball milling.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a process diagram of manufacturing a white light emitting diode by performing a transfer molding using an epoxy molding compound tablet containing a phosphor according to an embodiment of the present invention, Figure 2 is a phosphor according to an embodiment of the present invention A process chart for producing an included epoxy molding compound tablet.

Referring to FIG. 1, an epoxy molding compound is produced by mixing a phosphor powder and an epoxy powder (S10).

Referring to FIG. 2, a process of producing an epoxy molding compound is performed by putting a powder-type epoxy powder into a jar, putting an appropriate amount of balls into a ball, and performing ball milling at high speed for a short time to coarse epoxy. It begins with a process of grinding the particles of the powder into small, even particles (S11). Here, the ball milling process of grinding only the epoxy powder will be referred to as a primary ball milling process.

The first ball milling process is suitably performed at 100 to 130 rpm for about 20 to 40 minutes, and a preferable time is about 30 minutes.

Evenly pulverizing the particles of the epoxy powder in the first ball milling process is because the more evenly pulverized particles of the epoxy powder can be uniformly mixed when mixed with the phosphor.

After completion of the first ball milling process, an appropriate amount of phosphor is added to a jar containing epoxy powder evenly ground by the first ball milling process, and ball milling is carried out at a low speed for a short time to uniformize the epoxy powder and the phosphor. Mixing to produce an epoxy molding compound (EMC) (S12). Here, the ball milling process performed to mix the epoxy powder and the phosphor will be referred to as a secondary ball milling process.

The second ball milling process is appropriately performed at 40 to 80 rpm for about 20 to 40 minutes, and a preferable time is about 30 minutes.

The low speed when mixing the epoxy powder and the phosphor in the secondary ball milling process is to prevent the phosphor from being pulverized into fine particles in the ball milling process.

In addition, the ball milling process is divided into a primary ball milling process for pulverizing the epoxy powder and a secondary ball milling process for mixing the epoxy powder and the phosphor to perform ball milling after the epoxy powder and the phosphor are put together. This is because the phosphor can be pulverized into fine particles while the epoxy powder is pulverized.

The reason why the phosphor powder is prevented from being pulverized into fine particles is that when the phosphor powder is pulverized into fine particles of 5 μm or less through a ball milling process, fine particles of 5 μm or less cause white dispersion in large areas during transfer molding. Because.

In the case of transfer molding, the epoxy molding compound tablet is injected by the pressure. At this time, the particles of 5 μm or less are pushed to the far end by the pressure and are concentrated toward the far end.

Therefore, when arranging several PCBs and performing transfer molding for them, the phosphor is not uniform in the epoxy resin molded in each LED according to the position where each PCB is arranged, and the light emission becomes stronger as the farther away from the transfer molding inlet. Will be characterized. Therefore, the phosphor powder is first introduced into a jar in the second ball milling process, separate from the first ball milling process of pulverizing the epoxy powder so that phosphor particles of 5 μm or less resulting in such a result are not generated. It is to be mixed with the epoxy powder evenly ground through the milling process.

When an epoxy molding compound (EMC) is produced by performing ball milling for a suitable time, the epoxy molding compound (EMC) is produced as an epoxy molding compound tablet using a jig (S13).

When the epoxy molding compound tablet is prepared, die attach the blue LED chip and the zener diode to the PCB substrate using a paste, and wire bond the chip pad and the PCB substrate using Au wire (S20). .

After performing wire bonding, a few seconds-several minutes to preheat the PCB (S30).

After preheating to some extent, the PCB substrate wire-bonded with the blue LED chip is transferred to an EMC tablet including a phosphor (S40).

Then, the molded PCB substrate is separated into LEDs by individual white light emitting diodes by performing a sawing and barreling process (S50).

3 to 5 are graphs for each PCB of a white LED according to a comparative example manufactured using an epoxy-molded compound tablet produced in a state where ball milling was performed for 80 minutes at 80 rpm in a state where epoxy powder and phosphor were put together. .

6 to 8 are graphs showing the improvement of the white scatter for each PCB manufactured by performing the transfer molding using the epoxy molding compound tablet containing the phosphor according to an embodiment of the present invention for each PCB.

3 to 8 using an epoxy molding compound tablet produced through the first ball milling process for grinding the epoxy powder and the second ball milling process for mixing the epoxy powder and the phosphor according to an embodiment of the present invention When the transfer molding is carried out, it can be seen that the white scatter of each PCB in the white light emitting diode is reduced compared to the comparative example that is not so much improved.

The present invention is not limited to the embodiments described above, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

For example, an embodiment of the present invention has been described for manufacturing a white light emitting diode emitting white light by performing a transfer molding on a blue LED chip, but a white light emitting diode emitting white light by performing a transfer molding on an ultraviolet LED chip. It is possible to apply to manufacturing the.

In addition, the embodiment of the present invention has been described for manufacturing a white light emitting diode that emits white light by performing a transfer molding on a blue LED chip, but is not applicable to the production of various white light emitting device having a light emitting region as well as a white light emitting diode. It is possible.

In addition, the embodiment of the present invention has been described for manufacturing a white light emitting diode that emits white light by performing a transfer molding on a blue LED chip, but not only white light but also multicolor light emitting devices of various colors on a blue LED chip or an ultraviolet LED chip. Applicable to

According to the present invention, when producing an epoxy-molded compound tablet for use in transfer molding, the secondary ball mill evenly mixes the epoxy powder evenly pulverized by the first ball milling process and the first ball milling process with the phosphor when the epoxy powder is compounded. The ball milling process is divided.

Therefore, it is possible to prevent the problem that white dispersion is increased due to phosphor fine particles of 5 μm or less generated during the ball milling process by putting the epoxy powder and the phosphor together in a jar.

Therefore, when performing transfer molding, irrespective of the position where each PCB is arranged, the phosphors are uniformly distributed in the epoxy resin molded in each LED, thereby reducing the white dispersion, thereby improving the concentration at the target coordinates, thereby achieving uniform emission characteristics. The light emitting elements can be mass produced.

Claims (7)

Method of producing an epoxy molding compound tablet containing a phosphor for the transfer molding of the light emitting device, Grinding the powder type epoxy powder, Generating an epoxy molding compound (EMC) in which the pulverized epoxy powder and the phosphor powder are mixed; Epoxy molding compound tablet production method comprising the step of producing the epoxy molding compound into an epoxy molding compound tablet. The method according to claim 1, The pulverizing step includes the step of crushing the powder-type epoxy powder in a jar and pulverizing through ball milling, The epoxy molding compound generating step comprises the step of mixing the epoxy powder and the phosphor powder pulverized through the ball milling in the jar (jar) through a ball milling method of producing an epoxy molding compound tablet. The method according to claim 2, The ball milling process for the grinding is carried out for 20 to 40 minutes at 100 ~ 130rpm, The ball milling process for the mixing is epoxy molding compound tablet production method performed for 20 to 40 minutes at 40 to 80rpm. In the method of manufacturing a white light emitting device by transferring the epoxy molding compound in which the phosphor is mixed in the LED chip, Generating an epoxy molding compound in which the phosphor powder and the powder type epoxy powder are mixed; Transfer molding the PCB substrate to which the LED chip is wire bonded to the epoxy molding compound; Separating the PCB substrate into individual white light emitting devices through a sawing and barrel process; The epoxy molding compound generation step, Grinding the powder type epoxy powder, Generating an epoxy molding compound (EMC) in which the pulverized epoxy powder and the phosphor powder are mixed; The method of manufacturing a white light emitting device comprising the step of producing the epoxy molding compound into an epoxy molding compound tablet. The method according to claim 4, The pulverizing step includes a process of putting the powder-type epoxy powder in a jar and pulverizing through ball milling for 20 to 40 minutes at 100 to 130 rpm, The epoxy molding compound generating step is a white light emitting device comprising the step of mixing the ball-milling the epoxy powder and the phosphor powder in the jar (40) for 20 to 40 minutes by ball milling at 40 ~ 80rpm Manufacturing method. Epoxy molding compound tablet containing a phosphor for the transfer molding of the light emitting device, Powder type epoxy powder pulverized by the pulverization process, Epoxy molding compound tablet comprising a phosphor powder mixed with the epoxy powder pulverized by the grinding process, wherein the phosphor powder and the epoxy powder is mixed and formed into a tablet. The method according to claim 6, The epoxy powder is ground through the first ball milling, The phosphor powder is an epoxy molding compound tablet mixed through the secondary ball milling to the epoxy powder milled through the first ball milling.

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