KR101165216B1 - Low temperature sintering and filler that come environment-friendly binder that can treat with heat and is suitable to sealant glass-frit and crystallinity increase method - Google Patents

Abstract

The present invention is an environment-friendly (Pb-free) of glass frit widely used as a sealing material for displays and dye-sensitized solar cell electronic parts such as PDP, LCD, OLED, etc., and is fired at low temperature using glass frit having a transition point of 285 ° C and 430 ° C or less. However, the technical gist of the present invention is a filler suitable for an environmentally friendly lead-free glass frit used in manufacturing a binder or an encapsulant capable of heat treatment and a method of improving crystallinity of the filler.

  In the case of a display or an electronic component that allows the composite filler to be mixed with glass frit to be composited and the composite material is used to control the coefficient of thermal expansion and control the flow of viscosity at high temperature Finally, the binder or encapsulant that needs to be calcined or heat treated at the lowest temperature must be low temperature.

  Conventionally, a glass frit suitable as a binder or an encapsulant of a display or electronic component has been used at low temperature firing or heat treatment. However, with the recent release of RoHS, Pb-free systems have been developed, so a suitable filler for Pb-free systems is needed.

On the other hand, low temperature glass frit has a glass structure of Pb type or Pb-free type, such as SnO ₂ -P ₂ O _{5 type} , B ₂ O ₃ -ZnO type and Bi ₂ O3-B ₂ O ₃ type when used as a binder or sealing material. After this, the viscosity increases sharply, and most substrates and expansion coefficient aberrations occur during the heat treatment or the post-firing cooling process, and rapidly grow as time passes after fine cracks are generated during cooling.

  Therefore, in order to control the thermal expansion coefficient of the environmentally friendly leadless glass frit, to enhance the strength, and to maintain the viscosity at the firing temperature, it is necessary to mix and compound the crystallinity improving filler stronger than the environmentally friendly leadless glass frit. The binder and the encapsulant compounded by mixing the filler with the glass frit at respective ratios will maintain viscosity even at a low firing temperature at a low temperature, and 5 to 30 percent of the filler is added to adjust thermal expansion to prevent cracking after bonding with the substrate. I did not want to.

Therefore, in the present invention, an environmentally friendly composition and a transition temperature of tin oxide-phosphorus pentoxide having a transition temperature of 285 ° C. or less, and a bismuth oxide (Bi ₂ O ₃ ) -boron oxide (B ₂ O ₃ ) -zinc oxide (ZnO) system having a transition temperature of 430 ° C. Glass frit was prepared. As a filler suitable for this glass frit, eutectic, spodumene, petalite and cordierite crystals having negative or very low thermal expansion coefficients were synthesized at 1100 to 1350 ° C. When the composite filler is mixed with eco-friendly lead-free glass frit, composite materials are made of eco-friendly lead-free glass frit, filler composition and synthesis method suitable for controlling thermal expansion and viscosity, and method of improving the crystallinity of the filler. .

Description

Low temperature sintering and filler that come environment-friendly binder that can treat with heat and is suitable to sealant glass-frit and crystallinity increase method}

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filler suitable for environmentally friendly (lead-free) glass frit having a temperature of 430 ° C. or lower and capable of low temperature firing and heat treatment, and a technical field of improving crystallinity of the filler.

Composite materials for binders and encapsulants with a mixture of glass frit and filler are used for bonding or encapsulating materials between different materials (ceramic / ceramic, ceramic / metal, glass / glass, glass / metal, glass / ceramic) It is mainly used for forming component circuits.

  Cordierite (cordierite) was mainly used as a suitable glass frit filler because a glass frit composition system containing Pb was mostly used as a binder and an encapsulant in which glass frit and filler were mixed.

However, cordierite fillers are suitable for PbO-B ₂ O ₃ or PbO-B ₂ O ₃ -SiO ₂ based glass frit but P ₂ O ₅ based B ₂ O ₃ and Bi ₂ O _{3 which} are environmentally friendly Pb-free In the glass frit of the system, when fired at 430 ° C. and 500 ° C. or less, there is a problem that cracks occur due to bonding characteristics or expansion coefficient difference or sealing is difficult, and thus it is difficult to be applied as a filler.

Therefore, in the present invention, cordierite or lead titanate (PbTiO ₃ ) -based filler suitable for Pb-based glass frit is lead-free (Pb-free), in particular, P ₂ O ₅ -SnO ₂ and Bi ₂ O ₂ -B ₂ O ₂ It is intended to replace the filler suitable for the glass frit.

Pb-free glass frit is made of Pb-free glass frit having a transition point of 285 ° C. or lower or 430 ° C. or lower, respectively, to prepare P ₂ O ₅ -SnO ₂ and Bi ₂ O ₃ -BaO. As a result of the synthesis and application of suitable fillers, such as eucritite, spodumene, and petalite, binding and sealing were performed well, which could replace cordierite fillers applied to Pb-containing systems.

In addition, since the desired material is first synthesized and then pulverized to increase the crystallinity of the krypite, spodumene, and petalite filler crystals, the crystallinity is enhanced or volatilized at a high temperature in the composition during the first synthesis. A method of improving the crystallinity by two or more by adding 10% by weight of lithium oxide (Li ₂ O) which is easy to add to the entire primary synthetic composition.

In order to optimize the viscosity and thermal expansion at the temperatures processed by the binder and encapsulant of displays or electronic parts used for firing or heat treatment at low temperatures, they are mainly used in PbO-B ₂ O ₃ and PbO-ZnO-based glass plates. Filler composition and filler synthesis method suitable for Pb-free system because light or lead titanate is used as filler but it is not suitable for Pb-free P ₂ O ₅ -SnO ₂ and Bi ₂ O ₃ -BaO glass frit. The technical task of improving filler crystallinity to be used as a bonding material or sealing material in displays and electronic parts has been made.

To produce a binder suitable for the sealing material-based Pb-free P ₂ O ₅ -SnO-based and _{Bi 2 O 3 -B 2 O 3} -BaO -based glass frit to melt pulverized at 1100 ℃, and suitable for the above glass frit The filler was maintained at 1100 ~ 1350 ° C. for 1 ~ 5 hours to synthesize krypite, spodumene, and petalite, and the composite material was mixed with glass frit and the composite filler to form a binder and sealing material for low temperature baking and heat treatment. It was set as the problem solving means.

After preparing glass frit with Pb-free system, it was prepared as a binder and sealing material for low temperature firing and heat treatment by synthesizing composite material suitable for Pb-free system. With the above inventions, eco-friendly bonding materials and sealing materials used for displays and electronic parts are made, and when they are fired or heat treated at low temperatures during manufacturing of the above parts, they can be used for a long time without causing defects or failure due to controlled viscosity or thermal expansion coefficient. High reliability was secured

≪ Example 1 >

Lithium oxide (Li ₂ O), 1.5 mol tin oxide (SnO ₂ ) 0.9 mol phosphorus pentoxide (P ₂ O ₅ ), 0.05 mol alumina (Al ₂ O ₃ ), 0.1 mol zinc oxide (ZnO) 0.1 mole of titanium (TiO ₂ ) and zirconia (ZrO ₂ ), respectively, or a combination of two, and then a reducing agent for low temperature in order to change the melting atmosphere to a reducing atmosphere in order to change the tin oxide from tetravalent to divalent when melting. For sucrose and high temperature, carbon is added in 3 to 5 percent and 2 percent in weight ratio to the total weight of glass frit, mixed for 24 hours, and then melted at 900 to 1100 ° C. Average particle size 1 was pulverized in a jet mill to 2.7 ~ 4.8㎛ as shown in Figure 1 to prepare a glass frit. The glass frits had a transition temperature of 250 to 270 캜, a softening temperature of 260 to 290 캜, and a thermal expansion coefficient of 110 to 130x10 ^-7 / 캜.

<Example 2>

1.5 mol SnO ₂ , 0.9 mol P ₂ O ₅ , 0.05 mol Al ₂ O ₃ , 0.1 mol boric acid (B ₂ O ₃ ), 0.05 mol calcium oxide (CaO), 0.1 mol lithium oxide (Li ₂ O) Mixing as in <Example 1>. Melt grinding. The glass frits had a transition temperature of 285 ° C, a softening temperature of 305 ° C, and a thermal expansion coefficient of 117 to 120x10 ^-7 / ° C.

&Lt; Example 3 >

0.2 moles of bismuth oxide (Bi ₂ O ₃ ), 0.2 moles of boric acid (B ₂ O ₃ ), 0.15 moles of barium oxide (BaO), 0.4 moles of zinc oxide (ZnO), 0.05 moles of alumina (Al ₂ O ₃₎ ) Was mixed for 24 hours, melted at 1,100 ° C., and then ground in a jet mill to have an average particle size of 2.7˜4.8 μm to prepare a glass frit. The glass frits had a transition temperature of 432.2 ° C, a softening temperature of 456.9 ° C, and a thermal expansion coefficient of 81.4x10 ^-7 / ° C.

<Example 4>

As a filler to be used in <Example 1, 2>, it is shown in Table 1 as a composition for synthesizing eu cryptite (eu cryptite), spodumene, and petalite crystals.

<Table 1> Filler Composition (Unit: Mole)

Filler Name Lithium Oxide (Li ₂ O) Alumina (Al ₂ O ₃ ) Silica (SiO ₂ ) Euliptite One One 2 Spodumene One One 4 Petalite One One 8

The eutectic was synthesized as shown in <Figure 2> when it was synthesized by mixing in a ball mill for 24 hours with the same composition as lithium oxide and alumina silica of <Table 1>, and then maintaining it for 1 hour at 1100 ~ 1300 ° C. In the case of synthesis for 1 to 5 hours at 1300 ° C., the synthesis was carried out to a similar degree even if the retention time was extended as shown in FIG. 3.

In addition, when mixed with a composition ratio of lithium oxide alumina silica and maintained for 1 hour at 1100 ~ 1300 ℃ synthesized spodumene was synthesized as spodumene crystals as shown in Figure 4.

In addition, when confirming the relationship between the synthesis temperature and the holding time was maintained for 1 hour at 1300 ℃ and 5 hours at 1250 ℃ to compare and confirm as shown in <Figure 5> spodumene having almost the same crystallinity was synthesized.

 Petarite was synthesized by maintaining at 1100 ~ 1300 ℃ for 1 hour in the same manner as in the eutectic and spodumene as shown in Figure 6. At this time, as the synthesis temperature increases as shown in FIG.

 Euphrite, spodumene, and petarite synthesized above were pulverized and used to have an average particle size of 10-20 μm.

Example 5

In Example 4, in order to increase the crystallinity of the eu kryptite, spodumene, and petalite, as shown in FIG. In the case of secondary synthesis at 1300 ° C. for 1 hour, and the second synthetically synthesized eu cryptite, the mixture was pulverized again and then synthesized in the third manner. In this case, the second and third resynthesis increased the crystallinity.

Example 6

In order to increase the crystallinity of the eu cryptite synthesized in Example 4, Li ₂ O was added to the eu kryptite synthesized in Example 4 in a weight ratio of 10% by weight based on the whole krypite composition for 24 hours. After mixing at 1300 ℃ for 5 hours. As shown in <Example 5>, it was more excellent in the case of adding 10% of Li ₂ O crystallinity as shown in <Figure 8> than <Figure 7>, which was subjected to the 2.3th resynthesis treatment to increase the crystallinity.

In addition, as shown in FIG. 8, the crystallinity increased when the 10% Li ₂ O was first synthesized and then resynthesized.

Example 7

1 mole of magnesia (MgO), 1 mole of alumina (Al ₂ O ₃ ), 2 moles of silica (SiO ₂ ) were mixed in a ball mill for 24 hours and then maintained at 1300 ° C. for 3 hours to produce cordierite crystals.

In this case, the coefficient of thermal expansion was 20 ~ 30x10 ^-7 / ℃ and the average particle size was about 15 ㎛ due to the cordierite characteristics.

&Lt; Example 8 >

The glass frit of <Examples 1,2,3> and <Example 6,7> were synthesized in order to have a coefficient of thermal expansion suitable for each substrate (substrate, body) and to prevent the glass frit from flowing down when it had an initial viscosity. The filler was mixed to prepare a composite powder (composite). This powder was used as a binder or sealant that can be calcined and heat treated at 500 ° C or lower, including various ceramic-ceramic, ceramic-glass, metal-metal, metal-ceramic, glass-glass, and polymer-polymers.

 1 to 10 weight percent of glass frit was added to the eutectic filler, followed by baking and heat treatment to measure the coefficient of thermal expansion.

The thermal expansion coefficient of the composite is shown in FIG. When the addition of glass frit 5 percent by weight of the thermal expansion coefficient of -eucryptite increased from -27.3x10 ^-7 / ℃ to 4.1x10 ^-7 / ℃.

On the other hand, when the glass frit melted and melted in <Example 2> was mixed with 10, 15, and 20 percent by weight of the krypite synthesized in <Example 2>, the thermal expansion coefficient was as shown in <Fig. 10>, respectively. 93.7, 86.2 and 82.9 × 10 ⁻⁷ / ° C.

In addition, the results of observing the softening state according to the firing temperature are shown in <Fig. 9>. In the case of krypite, as shown in <Fig. 11>, the contact angles were different at the softening degree, but started at 400 ° C. The contact angle was 450 ° C or higher at 450 ° C and 135 ° C or higher at 500 ° C. Therefore, the composite material mixed with SnO ₂ -P ₂ O ₅ based glass frit and 5 to 15 percent eu cryptite filler can be used as a binder and an encapsulant below 500 ° C.

Example 9

The coefficient of thermal expansion was measured for the sample that was reheat-treated after 5, 10 and 15 percent of the cordierite synthesized in Example 7 was added to the glass frit melted and pulverized in <Example 2>. It is shown in FIG.

Thermal expansion coefficient values were 106, 89.4 and 83.6 × 10 ⁻⁷ / ° C. When 15% cordierite was mixed with the glass frit melted and pulverized in <Example 3>, the result was 84 × 10 ⁻⁷ / ° C.

FIG. 13 was added to the glass frit melted in <Example 2> in 5 to 15% by weight of the cordierite synthesized in <Example 7> by heat treatment to observe the softening state. As a result, when 5% of cordierite was added, it softened around 400 ℃, but in 10 or 15%, it occurred around 450 ℃. Therefore, it can be used as a binder or sealing material at less than 500 ℃.

1 is a particle size and distribution of the synthesized eu cryptite according to the grinding time (a: 1 hour, b: 3 hours, c: 5 hours)

2 is an X-ray diffraction pattern of the composite synthesized for 1 hour at each temperature

Figure 3 is an X-ray diffraction analysis pattern of the composite according to the holding time at 1300 ℃.

4 is an X-ray diffraction analysis pattern of a composite synthesized by holding at 1100 ° C (a) and 1200 ° C (b) for 1 hour.

5 is an X-ray diffraction analysis pattern of a composite synthesized according to synthesis temperature and holding time.

6 is an X-ray diffraction analysis pattern of the composite synthesized for 1 hour at each temperature.

7 is an X-ray diffraction analysis pattern of the resynthesized composite.

FIG. 8 is a comparison of X-ray diffraction analysis patterns of a composite synthesized by adding 10% Li ₂ O in eutectic composition. FIG.

※ (a): Euliptite composition compound.

(b): 10% Li ₂ O-added compound (1300 ° C. 5 hours)

(c): Compound synthesized twice at 5 hours at 1300 ° C. after addition of 10% Li ₂ O

9 is a thermal expansion curve after the addition of 1 ~ 10% glass frit to the krypite.

10 is a thermal expansion curve after the addition of 10 ~ 20% of the krypite to glass frit.

Fig. 11 is a temperature heat softening state after adding cryptic filler to glass frit.

12 is a thermal expansion curve in which cordierite filler is added to glass frit.

13 is a softening state for each temperature after the cordierite filler is added to the glass frit.

Claims (5)

1.5 mol of tin oxide (SnO ₂ ), 0.9 mol of phosphorus pentoxide (P ₂ O ₅ ), 0.05 mol of alumina (Al ₂ O ₃ ), as main compositions, 430 by adding 0.1 mole or two or more moles from the group consisting of zinc oxide (ZnO), lithium oxide (Li ₂ O), titanium oxide (TiO ₂ ), zirconia (ZrO ₂ ) and potassium oxide (Ca0) Glass frit capable of firing and heat treatment below ℃. The method of claim 1, Glass frit characterized by adding 0.1 mol of boric acid (B ₂ O ₃ ) to the main composition consisting of 1.5 mol tin oxide, 0.9 mol phosphorus pentoxide, 0.05 mol alumina. delete delete delete

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