KR20120046390A - Ceramics composition for low temperature firing and method of manufacturing ceramic with high reflectivity for led package using the same - Google Patents

Abstract

PURPOSE: A ceramic composition for low-temperature firing and a manufacturing method of ceramic for LED package having high reflectivity using thereof are provided to co-fire with conductive paste at low temperature by including low melting point glass powder and fillers. CONSTITUTION: A manufacturing method of ceramic for LED package having high reflectivity comprises the next steps: preparing glass frit having low melting point(S210); forming a ceramic composition(S220); and plasticizing the ceramic composition at 800-900 deg. Celsius(S230). The ceramic composition for low-temperature firing comprises glass frit having a softening point of 650-800 deg. Celsius and more than one kind of fillers which is selected from amorphous quartz(a-quartz), al2O3, zrO2, caZrO3, mullite, zircon, and TiO2. The filler is added as 50-200 parts by weight based on 100.0 parts by weight of glass frit.

Description

Ceramic composition for low temperature firing and method for manufacturing ceramic for LED package having high reflectance using the same

The present invention relates to a low-temperature calcined ceramic, and more particularly, to a low-temperature calcined ceramic, which has a high reflectivity and can be co-fired with a conductive paste for forming an electrode such as Ag paste at a low temperature to be used as a package body or a reflector of an LED package. It relates to a composition.

1 illustrates a general mounted LED package structure.

Referring to FIG. 1, the mounted LED package 100 may include a package body 110, an LED chip 120 mounted on the package body 110, and a connection of the LED chip 120 to a printed circuit board. The wire 130 and a reflector 140 reflecting light generated from the LED chip 120 on the upper edge of the package body 110.

In the LED package, the package body 110 is mainly formed of a plastic material. In the LED package using the plastic body, the plastic body may be deformed by heat emitted from the LED, and the life of the LED package may be shortened due to yellowing caused by heat.

In order to solve the problem caused by heat, a heat sink has recently been introduced into an LED package, thereby dissipating heat generated from the LED chip to the outside to prevent deformation of the plastic body. However, the use of such plastic bodies and heatsinks requires complex processes to produce the smallest package.

Therefore, recently, in order to solve the problems of the plastic package body as described above, a ceramic material is used as the LED package body.

On the other hand, in the case of the reflector 140, a metal reflector is mainly used to exhibit high brightness. However, in the case of such a metal reflector, the bonding between the metal reflector and the ceramic body may be weak, which may be a problem in the reliability of the product.

In addition, when manufacturing a package having a multifunction, the ceramic body is made of several layers, and the electrode is fired at the same time to produce the product. The high-temperature ceramic body package of Al ₂ O ₃ or AlN is made of tungsten (W) having low electrical conductivity. It has the disadvantage of applying only the electrode material.

SUMMARY OF THE INVENTION An object of the present invention is to provide a ceramic composition for low temperature firing, which has high reflectivity after firing and is capable of co-firing with a conductive paste for forming an electrode at a low temperature.

Another object of the present invention is to provide a ceramic for LED package having a high reflectance using the ceramic composition for low temperature baking.

Low temperature sintering ceramic composition according to an embodiment of the present invention for achieving the above object is a) glass powder having a softening point of 650 ~ 800 ℃ or less and b) amorphous quartz (a-quartz), Al ₂ O ₃ , ZrO ₂ , At least one filler selected from CaZrO ₃ , mullite, zircon, and TiO ₂ .

At this time, the filler is preferably added to 50 to 200 parts by weight relative to 100 parts by weight of the glass powder.

In addition, the glass powder is Al ₂ O ₃ : 1 to 5% by weight, ZrO ₂ : 10% by weight or less, B ₂ O ₃ : 1 to 10% by weight, CaO: 1 to 10% by weight, MgO: 1 to 5% by weight %, BaO: 10% by weight or less, ZnO: 1 to 5% by weight, Na ₂ O: 1 to 5% by weight, K ₂ O: 1 to 10% by weight and the balance of SiO ₂ can be made.

Moreover, it is preferable that the said glass powder is 2-4 micrometers in average particle diameter (D50). In this case, the filler is preferably an average particle diameter (D50) of 0.5 ~ 5㎛.

Ceramic manufacturing method for an LED package according to an embodiment of the present invention for achieving the above another object comprises the steps of preparing a glass powder having a softening point of 650 ~ 800 ℃ or less; One or more fillers selected from amorphous a-quartz, Al ₂ O ₃ , ZrO ₂ , CaZrO ₃ , mullite, zircon and TiO ₂ are added to the glass powder to form a ceramic composition. Making; And firing the ceramic composition at 800 to 900 ° C.

The ceramic composition for low temperature firing according to the present invention can be fired at the same time as the electrode forming paste at a low temperature, and also has the advantage of having a high reflectance of about 90% or more after firing by using a filler such as ZrO ₂ .

Therefore, the LED package manufactured using the ceramic composition for low temperature firing according to the present invention may have a high reflectance, and has an advantage of excellent life characteristics as compared with the LED package based on plastic material.

1 illustrates a general mounted LED package structure.
2 is a flowchart schematically showing a method of manufacturing a ceramic for LED package according to an embodiment of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and those skilled in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims.

Hereinafter, a ceramic composition for low temperature firing according to a preferred embodiment of the present invention and a method of manufacturing a ceramic for LED package having a high reflectivity using the same will be described in detail with reference to the accompanying drawings.

The ceramic composition for low temperature firing according to the present invention is a) glass powder having a softening point of 650 ~ 800 ℃ or less and b) amorphous quartz (a-quartz), Al ₂ O ₃ , ZrO ₂ , CaZrO ₃ , mullite (mullite), zircon (zircon) and TiO _{2 It} is characterized in that it comprises one or more fillers selected from.

The filler is preferably added to 50 to 200 parts by weight based on 100 parts by weight of the glass powder. When the content of the filler is less than 50 parts by weight, it is difficult to secure sufficient reflectance. On the contrary, when the content of the filler is more than 200 parts by weight, the firing temperature is increased, which makes it difficult to co-fire with the electrode forming paste. There is a problem that does not work well.

The glass powder is preferably made from low melting glass having a softening point (Ts) of preferably 650 to 800 ° C, more preferably 700 to 750 ° C. When the softening point of the glass powder is within the above range, the firing temperature of the ceramic composition mixed with the filler may be 800 to 900 ° C., so that the conductive paste for forming electrodes of the LED package such as Ag paste or Ag-Pd paste may be simultaneously used at low temperature. Firing is possible.

As such a glass composition which satisfies the conditions, Al ₂ O ₃ : 1 to 5% by weight, ZrO ₂ : 10% by weight or less, B ₂ O ₃ : 1 to 10% by weight, CaO: 1 to 10% by weight, MgO : 1 to 5% by weight, BaO: 10% by weight or less, ZnO: 1 to 5% by weight, Na ₂ O: 1 to 5% by weight, K ₂ O: 1 to 10% by weight and the balance of SiO ₂ can do.

Table 1 shows the glass compositions that can be applied to the present invention.

[Table 1]

Referring to Table 1, in the case of the glass having the composition shown in Table 1, it can be seen that the softening point of all the glass composition of the a ~ d type is 650 ~ 800 ℃.

In addition, the glass powder preferably has an average particle diameter (D50) of 2.0 to 4.0 µm, more preferably 2.5 to 3.0 µm. When the average particle diameter of the glass powder is less than 2 μm, even dispersion may be difficult. On the contrary, when the average particle diameter of the glass powder exceeds 4 μm, the firing density may decrease.

In this case, the filler is preferably an average particle diameter (D50) of 0.5 ~ 5㎛, more preferably 2.0 to 5.0㎛ can be presented. When the average particle diameter of the filler is less than 0.5 μm, there is a problem in that the baking is not performed well. On the contrary, when the average particle diameter of the filler exceeds 5 μm, dispersion is not well achieved and the plastic density may be reduced.

On the other hand, when Al ₂ O ₃ and ZrO ₂ were used as fillers, the reflectance was measured to be higher when using an average particle diameter in the range of 2.0 to 5.0 μm than when using an average particle diameter of less than 2.0 μm. When the thickness is less than 2 μm, the filler melts into the glass matrix, and as a result of the calcination, the reflectance is changed to a relatively low glass phase, which may be considered to result in an overall decrease in reflectance.

The average particle diameter (D50) of such glass powder or filler can be adjusted in a wet or dry milling process.

2 is a flowchart schematically showing a method of manufacturing a ceramic for LED package according to an embodiment of the present invention.

Referring to FIG. 2, the illustrated ceramic manufacturing method for the LED package includes a low melting point glass preparing step (S210), a ceramic composition forming step (S220), and a baking step (S230).

In the low melting point glass preparation step (S210), a softening point provides glass powder having a 650 to 800 ° C or less.

As shown in Table 1, the glass powder is Al ₂ O ₃ : 1 to 5 wt%, ZrO ₂ : 10 wt% or less, B ₂ O ₃ : 1 to 10 wt%, CaO: 1 to 10 wt%, MgO : 1 to 5% by weight, BaO: 10% by weight or less, ZnO: 1 to 5% by weight, Na ₂ O: 1 to 5% by weight, K ₂ O: 1 to 10% by weight and the balance of SiO ₂ In addition, the softening point can use what is 650-800 degreeC.

The glass powder may be formed by weighing materials having the glass composition, mixing them, and melting them at a platinum crucible at 1500 to 1600 ° C., forming a quench liquid in a water-cooling manner, and drying the formed glass. It may be prepared by a process including a glass powder forming step of wet-pulverizing and powdered by a wet ball mill device.

In the ceramic composition forming step (S220), a filler is added to the glass powder to form a ceramic composition. The filler may be amorphous a (quartz), Al ₂ O ₃ , ZrO ₂ , CaZrO ₃ , mullite, zircon, TiO _2, etc., and these may be used alone or in combination of two or more thereof. It is available.

At this time, as described above, the filler is preferably added to 50 to 200 parts by weight relative to 100 parts by weight of the glass powder. In addition, it is preferable that the glass powder has an average particle diameter (D50) of 2 to 4 µm, and the filler has an average particle diameter (D50) of 0.5 to 5 µm.

In the firing step (S230), the ceramic composition is poured into a mold having a molded part of a main body shape of an LED package or a mold having a molded part of a main body and a reflector coupling shape, and then 800 corresponding to the firing temperature of the conductive paste for forming an electrode in the LED package. Baking at ~ 900 ℃.

The ceramic prepared according to the present invention has the advantage of being capable of firing at the same time as the electrode forming paste of the LED package such as Ag paste at a relatively low temperature as it is manufactured by baking at 800 ~ 900 ℃, excellent reflectance of about 90% or more It can be used as a package main body or a reflector of an LED package.

Example

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

Each specimen of the Example was produced in the shape of a coin-shaped disk, and the surface polishing was performed after sintering.

In addition, each specimen of the Example was measured the reflectance (reflectance) between 200 ~ 800 nm using UV-2550 (Shimadzu, UV-Vis spectrophotometers).

Example 1

Various fillers were mixed with the glass powder having the composition of Table 1 to form a ceramic composition, and then sintered at 850 to 900 ° C. to measure respective reflectances, and the results are shown in Table 2 below.

TABLE 2

Referring to Table 2, each composition was well sintered at a low temperature as a whole. Referring to Table 2, in particular, Al ₂ O ₃ was applied to the c-type glass composition of the ZrO ₂ series and the d-type glass composition of the K ₂ O series. When ZrO ₂ and ZrO ₂ filler were used, high reflectance of about 90 ~ 95% was shown.

Example 2

After sintering the ceramic composition applying Al ₂ O ₃ as a filler to the glass powder at 800 ~ 900 ℃, the reflectance of the average particle diameter (D50) of the filler was measured, and the results are shown in Table 3.

[Table 3]

Referring to Table 3, it can be seen that the larger the average particle diameter of Al ₂ O 3 in the same glass type, the greater the reflectance.

In particular, the smaller the size of the filler can be expected to have a high reflectivity because it can have a smooth dispersion characteristics overall in the glass base material, but actually appeared to have a lower reflectance. This is due to the fact that the filler having a small particle size melts into the glass matrix upon heating, and the sintered body is changed into a glass phase having a relatively low reflectance, resulting in a lower overall reflectance.

Example 3

After sintering the ceramic composition to which the ZrO ₂ was applied to the glass powder at 800 to 900 ° C., the reflectance of the filler to the average particle diameter (D50) was measured, and the results are shown in Table 4 below.

[Table 4]

Referring to Table 4, it can be seen that when ZrO ₂ is used as the filler, the reflectance is better than when Al ₂ O ₃ is used as the filler. In the case of ZrO _2, the larger the average particle diameter of the filler was, the higher the reflectance was.

As described above, the ceramic composition for low temperature firing according to the present invention can be fired at a low temperature of about 800 ~ 900 ℃, can be fired at the same time as the electrode in the LED package, approximately 90% using a filler such as ZrO ₂ The above high reflectance can be exhibited and can be used as a package body of an LED package or as a package body and a reflector.

In the above description, the embodiment of the present invention has been described, but various changes and modifications can be made at the level of those skilled in the art. Such changes and modifications may belong to the present invention without departing from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.

110: package body
120: LED chip
130: wire
140: reflector
S210: low melting glass powder preparation step
S220: step of forming ceramic composition
S230: Firing Step

Claims (10)

a) a glass powder having a softening point of 650 to 800 ° C. or lower and b) 1 selected from a-quartz, Al ₂ O ₃ , ZrO ₂ , CaZrO ₃ , mullite, zircon and TiO ₂ . A ceramic composition for low temperature firing, comprising at least one filler.
The method of claim 1,
The filler
50 to 200 parts by weight, based on 100 parts by weight of the glass powder, characterized in that the ceramic composition for low-temperature baking.
The method of claim 1,
The glass powder is
Al ₂ O ₃ : 1 to 5 wt%, ZrO ₂ : 10 wt% or less, B ₂ O ₃ : 1 to 10 wt%, CaO: 1 to 10 wt%, MgO: 1 to 5 wt%, BaO: 10 wt A low-temperature firing ceramic composition, comprising:% or less, ZnO: 1 to 5% by weight, Na ₂ O: 1 to 5% by weight, K ₂ O: 1 to 10% by weight, and a balance of SiO ₂ .
The method of claim 1,
The glass powder is
Ceramic composition for low-temperature baking, characterized in that the average particle diameter (D50) is 2 ~ 4㎛.
The method of claim 4, wherein
The filler
An average particle diameter (D50) is 0.5 ~ 5㎛ ceramic composition for low temperature firing, characterized in that.
(a) preparing a glass powder having a softening point of 650 to 800 ° C or less;
(b) adding at least one filler selected from amorphous quartz, Al ₂ O ₃ , ZrO ₂ , CaZrO ₃ , mullite, zircon, and TiO ₂ to the glass powder to Forming a composition; And
(c) calcining the ceramic composition at 800 to 900 ° C.
The method of claim 6,
The filler
The method of manufacturing a ceramic for an LED package, which is added in an amount of 50 to 200 parts by weight based on 100 parts by weight of the glass powder.
The method of claim 6,
The glass powder is
Al ₂ O ₃ : 1 to 5 wt%, ZrO ₂ : 10 wt% or less, B ₂ O ₃ : 1 to 10 wt%, CaO: 1 to 10 wt%, MgO: 1 to 5 wt%, BaO: 10 wt A method of manufacturing a ceramic for an LED package, characterized by having a glass composition consisting of% or less, ZnO: 1 to 5% by weight, Na ₂ O: 1 to 5% by weight, K ₂ O: 1 to 10% by weight, and a balance of SiO ₂ .
The method of claim 8,
The glass powder is
A melt-forming step of mixing the materials having the glass composition and melting at 1500-1600 ° C. in a platinum crucible;
A glass forming step of cooling the melt by a water cooling method; And
And a glass powder forming step of wet grinding the glass to powder the glass.
The method of claim 6,
The glass powder has an average particle diameter (D50) of 2 ~ 4㎛, the filler is a ceramic manufacturing method for the LED package, characterized in that the average particle diameter (D50) of 0.5 ~ 5㎛.

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