Antimony-free glass, antimony-free frit and a glass package that is hermetically sealed with the frit

Cross-reference of related applications

This application claims benefits under 35 USC §119 (e) of US Provisional Patent Application No. 61 / 106,730 filed on October 20, 2008, the contents of which are hereby referred to in their entirety. Incorporated in the specification.

The present invention relates to antimony-free glass, frits made of that glass, and tightly sealed glass packages sealed with frits suitable for protecting thin film devices that are sensitive to the surrounding environment. Some examples of such devices include organic light emitting diode (OLED) displays, sensors, photovoltaics and other optics. The present invention is illustrated using an OLED display as an example.

OLEDs have been the subject of high-value research and commercialization in recent years due to their use and availability in a wide variety of electroluminescent devices. For example, a single OLED can be used for discrete light emitting devices, or many OLEDs can be used for lighting or flat panel display applications (eg, OLED displays). OLED displays are known to be very bright, have good color contrast and a wide viewing angle. However, OLED displays, especially the electrodes and organic layers placed therein, are susceptible to degradation due to their interaction with the leakage of oxygen and moisture from the ambient environment into the OLED display. It is a well-known fact that the life of an OLED display can be significantly extended if the electrodes and organic layers within the OLED display are tightly sealed from the ambient environment. Unfortunately, until now, it has been very difficult to develop a sealing method for tightly sealing OLED displays. Below is a brief description of some of the factors that make it difficult to properly seal an OLED display: Oxygen (10) for tight sealing^-3cc / m²/ Day) and water (10)^-6g / m²/ Day) must provide a barrier. -The tightly sealed dimensions should be minimal (eg <2 mm) so as not to adversely affect the dimensions of the OLED display. -The temperature generated during the sealing process must not damage the materials (eg electrodes and organic layers) in the OLED display. For example, the first pixel of an OLED, located about 1-2 mm from the OLED display's encapsulation, should not be heated above 100 ° C during the encapsulation process. -Gas released during the sealing process should not contaminate the material in the OLED display. -Tight sealing should allow electrical connections (eg, thin film chromium) to be inserted into the OLED display.

Currently, one method of encapsulating OLED displays is to cure the various types of epoxy, inorganic and / or organic materials that form the encapsulation with UV light before use. For example, some encapsulations use composite material-based methods that allow the OLED display to be encapsulated with alternating layers of inorganic and organic materials. While these types of encapsulations usually provide good mechanical strength, they are very expensive and there are many cases of failure to prevent the diffusion of oxygen and moisture into OLED displays. Another common method of encapsulating OLED displays is to utilize metal welding or soldering. However, the resulting encapsulation is not durable over a wide range of temperatures due to the substantially different coefficients of thermal expansion (CTE) of the glass plate and metal in the OLED display.

<p num="0005"> Recently, glass-based frit has been used to seal a glass substrate plate in a glass package that provides excellent airtightness to the encapsulating device. However, many of these frits contain toxic elements such as antimony that pose an environmental hazard. There is a need for suitable glass-based frit for tightly sealing glass packages such as electronic devices (eg, for display-type applications) that do not contain antimony and have a low coefficient of thermal expansion (CTE).</p>

<p num="0006"> The present invention includes a tightly sealed OLED display and a method of manufacturing a tightly sealed OLED display. Essentially, a tightly sealed OLED display is manufactured by providing a first glass substrate plate and a second glass substrate plate and laminating frit onto the second glass substrate plate. Organic materials, such as those used in the manufacture of OLEDs, may be laminated on the first substrate plate. Then, using an irradiation source (eg, laser, infrared), The first glass substrate plate is connected to the second glass substrate plate and the frit that melts and forms a tight seal to protect the OLED is heated. A frit is a glass that contains vanadium and optionally an antimony-free filler so that the source softens the frit to form a bond as it heats the frit. This allows the frit to be melted to form a tight seal and avoids thermal damage to the OLED. Vanadium phosphate frit has proven to be particularly suitable for encapsulating, for example, just described types of glass packages, especially those of vanadium phosphate frit containing antimony. These frits are very stable, exhibit high optical absorption, and have excellent mechanical and water resistance. Unfortunately, antimony is a toxic element and efforts have been made to find alternatives to antimony that do not adversely affect other beneficial properties of the frit.</p><p num="0007"> Finally, antimony oxide, flow and glass transition temperature (T)_gFe with trace addition of ZnO to maintain)₂O₃+ TiO₂By substituting with the combination of Sb-vanadium phosphate frit, the excellent water resistance of Sb₂O₃Was maintained without. Fe₂O₃The presence of was found to have the greatest effect on improving tolerance. However, Fe₂O₃Existence of T_gAnd therefore exacerbates the flow of frit during sealing. In addition, high Fe₂O₃Frit with levels (approximately 25 mol% or more) tend to be oxidatively unstable and have the same schedule (425 ° C, N).₂Repeated samples calcined in (medium) exhibited different colors (brown or black), resulting in significant differences in the degree of flow. TiO₂By itself, it actually reduced water resistance to some extent, but (Fe₂O₃+ TiO₂) Combinations are high water resistance and low T_gIt turned out to be an ideal combination in terms of providing a laser encapsulating frit with both (400 ° C).</p><p num="0008"> Labbench tests in which the glass is exposed to 90 ° C distilled water, as well as 85 ° C / 85% relative humidity (RH) environmental chamber tests on laser-sealed samples, are both Fe.₂O₃-TiO₂-ZnO-V₂O₅-P₂O₅It is suggested that a system-based frit can form a tight seal after a laser seal that will withstand high humidity conditions for extended periods of time ( 1000 hours). Sb₂O₃(Fe₂O₃+ TiO₂) The result of the replacement is unexpectedly T_gWith a slight increase in (from 355 ° C to 370 ° C), the CTE of the base frit glass is reduced by about half (70-80 x 10).^-735 ~ 45 × 10 from / ° C^-7Decreased (to / ° C). Typically T_gLow glass and frit are 100 ~ 150 × 10^-7It has a CTE value in the range of / ° C. 40 × 10^-7Frit with a CTE value close to / ° C has the potential to seal fused silica and other low CTE substrates such as Kovar by adding fillers such as β-eucryptite. ..</p><p num="0009"> In one embodiment, V₂O₅ (40-50 mol%) P₂O₅ ( 20 mol% and &lt;25 mol%) ZnO (0-10 mol%) Fe₂O₃ (&gt; 0 mol% and &lt;25 mol%) TiO₂ (&gt; 0% and &lt;25 mol%) Antimony-free glass, including, is disclosed here, where TiO₂+ Fe₂O₃Is in the range of 20 mol% to 35 mol%.</p><p num="0010"> In another embodiment, the antimony-free glass V₂O₅ (40-50 mol%) P₂O₅ ( 20 mol% and &lt;25 mol%) ZnO (5-10 mol%) Fe₂O₃ (&gt; 0 mol% and &lt;25 mol%) TiO₂ (&gt; 0% and &lt;25 mol%) Including, here, TiO₂+ Fe₂O₃Is in the range of 20 mol% to 35 mol%.</p><p num="0011"> In yet another embodiment, the composition: V₂O₅ (40 mol%) P₂O₅ (20 mol%) ZnO (5 mol%) Fe₂O₃ (&gt; 0 mol% and &lt;25 mol%) TiO₂ (&gt; 0 mol% and &lt;25 mol%) Antimony-free glasses with are described here, where TiO₂+ Fe₂O₃Is 35 mol%.</p><p num="0012"> In another embodiment V₂O₅ (50 mol%) P₂O₅ (20 mol%) ZnO (10 mol%) Fe₂O₃ (&gt; 10 mol% and 15 mol%) TiO₂ (&gt; 5 mol% and 10 mol%) Antimony-free glass, including, is disclosed here, where TiO₂+ Fe₂O₃Is 20 mol%.</p><p num="0013"> Glass that does not contain antimony is T_g400 ° C and 35 x 10^-7/ ° C ~ 45 × 10^-7It is preferable to have a CTE in the range of / ° C. Antimony-free glass may include, for example, glass frit and optionally a CTE-lowering filler such as β-eucryptite.</p><p num="0014"> In yet another embodiment, V₂O₅ (40-50 mol%) P₂O₅ ( 20 mol% and &lt;25 mol%) ZnO (0-10 mol%) Fe₂O₃ (&gt; 0 mol% and 20 mol%) TiO₂ (&gt; 0% and 20 mol%) An antimony-free glass consisting of, where, TiO₂+ Fe₂O₃Is in the range of 20 mol% to 35 mol%.</p><p num="0015"> In another embodiment V₂O₅ (40-50 mol%) P₂O₅ ( 20 mol% and &lt;25 mol%) ZnO (5-10 mol%) Fe₂O₃ (&gt; 0 mol% and 20 mol%) TiO₂ (&gt; 0% and 20 mol%) Antimony-free glass, including, is disclosed here, where TiO₂+ Fe₂O₃Is in the range of 20 mol% to 35 mol%.</p><p num="0016"> In yet another embodiment, the glass package The first glass plate and With the second glass plate, With a frit that connects the first glass plate to the second glass plate and forms a tight seal between them, Is equipped with The frit contains antimony-free glass The antimony-free glass is: V₂O₅ (40-50 mol%) P₂O₅ ( 20 mol% and &lt;25 mol%) ZnO (0-10 mol%) Fe₂O₃ (&gt; 0 mol% and &lt;25 mol%) TiO₂ (&gt; 0 mol% and &lt;25 mol%) Including, here, TiO₂+ Fe₂O₃Is in the range of 20 mol% to 35 mol%.</p><p num="0017"> Glass frit without antimony is an alternative: V₂O₅ (40 mol%) P₂O₅ (20 mol%) ZnO (5 mol%) Fe₂O₃ (&gt; 0 mol% and &lt;25 mol%) TiO₂ (&gt; 0 mol% and &lt;25 mol%) May include, where TiO₂+ Fe₂O₃Is 35 mol%.</p><p num="0018"> In other embodiments, the antimony-free glass frit is: V₂O₅ (50 mol%) P₂O₅ (20 mol%) ZnO (10 mol%) Fe₂O₃ (&gt; 10 mol% and 15 mol%) TiO₂ (&gt; 5 mol% and 10 mol%) May include, here, TiO₂+ Fe₂O₃Is 20 mol%.</p><p num="0019"> In some embodiments, the antimony-free glass frit is: V₂O₅ (40-50 mol%) P₂O₅ ( 20 mol% and &lt;25 mol%) ZnO (5-10 mol%) Fe₂O₃ (&gt; 0 mol% and &lt;25 mol%) TiO₂ (&gt; 0 mol% and &lt;25 mol%) Including, here, TiO₂+ Fe₂O₃Is in the range of 20 mol% to 35 mol%.</p><p num="0020"> Antimony-free glass with frit is T_gIt is preferable to have 400 ° C. Glass frit without antimony is 35x10^-7/ ° C ~ 45 × 10^-7It is preferable to have a CTE in the range of / ° C. The frit may optionally contain a filler that lowers the CTE.</p><p num="0021"> In some embodiments, the glass package may further include an organic material, such as an organic material, including an organic light emitting diode laminated between the first glass plate and the second glass plate.</p><p num="0022"> In the process of the following descriptive description given in connection with the accompanying drawings without any implications of limitation, the present invention will be more easily understood and other objectives, features, details and advantages will be further enhanced. It will be clear. All of these additional systems, methods, properties, and advantages are contained within this description, are within the scope of the invention, and are intended to be protected by the appended claims.</p>

<figref num="1">Sectional drawing of the sealing of a typical OLED device using a frit according to an embodiment of the present invention.</figref><figref num="2">TiO in mol%, Sb-free frit according to embodiments of the present invention₂Fe₂O₃A plot of the coefficient of thermal expansion (CTE) as a function of substitution. Here, Fe₂O₃+ TiO₂Is 20 mol% to 35 mol%.</figref><figref num="3">Plot comparing CTE as a function of temperature of Sb-free frit and Sb-containing frit according to embodiments of the present invention under heating and cooling conditions.</figref>

The following detailed description describes exemplary embodiments that disclose specific details in order to provide a complete understanding of the invention for purposes of illustration, but not limitation. However, it will be apparent to those skilled in the art who have the benefit of the present disclosure that the present invention may be practiced in other embodiments without departing from the specific details disclosed herein. Let's do it. Furthermore, descriptions of well-known devices, methods, and materials may be omitted to avoid obscuring the description of the invention. Finally, where applicable, similar reference numbers refer to similar components. FIG. 1 represents a side sectional view illustrating the sealing of the basic components of a tightly sealed OLED display 10. The OLED display 10 includes a multi-layer stack of a first glass substrate plate 12, one or more OLED 14, frit 16 and a second glass substrate plate 18. The OLED display 10 includes a tight seal 20 formed of frit 16 that protects the OLED 14 located between the first glass substrate plate 12 and the second glass substrate plate 18. The tight seal 20 is typically located around the OLED display 10. The OLED14 is located inside the perimeter of the tightly sealed 20. The composition of the frit 16, more specifically the composition of the glass frit 16, and the method of forming the tight seal 20 from the frit 16 will be described in more detail below.

In one embodiment, the first and second substrate plates 12 and 18 are transparent glass plates. The frit 16 is laminated along the edge of the second glass substrate plate 18. For example, the frit 16 may be located approximately 1 mm from the free edge of the second glass substrate plate 18. In a preferred embodiment, the frit 16 is a cold antimony-free glass frit that contains vanadium to enhance the optical absorption of the frit. The frit 16 is provided with a filler such as β-eucryptite to reduce the coefficient of thermal expansion (CTE) of the frit so that it is compatible or substantially compatible with the CTEs of the two glass substrate plates 12 and 18. May be included.

The OLED14 and other electrical circuits are stacked on a second glass substrate plate 18. A typical OLED14 comprises an anode electrode, one or more organic layers, and a cathode electrode. However, it will be easily recognized that other environmentally sensitive components can also be laminated on the second glass substrate plate 18.

Optionally, the frit 16 can be pre-sintered into the first glass substrate plate 12 before the encapsulating glass substrates 12 and 18 are combined. To achieve this goal, the first substrate plate 12 with the laminated frit 16 is heated in a heating furnace or oven so that it adheres to the first glass substrate plate 12.

The first and second glass substrate plates 12, 18 are then coupled to the frit 16 and one or more OLEDs placed between them, where the frit 16 attaches the first substrate plate 12 to the second. The frit 16 is irradiated with an irradiation source 22 (eg, a laser or an infrared lamp) so as to form a tight seal 20 that connects and couples to the substrate plate 18. The tightly sealed 18 protects the OLED 14 by preventing ambient oxygen and moisture from entering the OLED display 10.

Of course, the irradiation wavelength should be in the high absorption wavelength band for a particular frit 16. For example, ytterbium (900 nm &lt;λ &lt;1200 nm), Nd: YAG (λ = 1064 nm), Nd: YALO (λ = 1.08 μm), and erbium (λ 1.5 μm) CW lasers with specific frit 16 and glass substrates. It can be used depending on the optical properties of the plates 12 and 18.

Note that the most common cold sealing frit is PbO based, as PbO frit has good flow and adhesion. However, the antimony-free frit disclosed herein not only has a lower CTE than PbO-based frit, but also has good water resistance comparable to conventional Pb-based frit in terms of adhesion.

In addition, P in good sealing frit₂O₅The role played by is important, but P₂O₅To enable the formation of stable glass, Sb from the viewpoint of laser encapsulation and post-encapsulation performance₂O₃And V₂O₅The effect of should not be ignored. In previous studies, Sb-free, Zn-based vanadium phosphate frit seals could only withstand a relatively mild environment of 60 ° C / 40% RH, whereas Sb- The seal made of vanadium phosphate frit mixed with Zn withstood 60 ° C / 85% RH before breaking. Conversely, a seal made entirely of vanadium frit Sb-phosphate withstood exposure to 85 ° C / 85% RH. However, Sb₂O₃Despite its role in improving water resistance, potential customer feedback shows that Sb₂O₃Concerns about its existence have consistently risen. Therefore, recently, emphasis has been placed on the development of glass suitable for environmentally friendly sealing frit, paying attention to toxic elements.

Sb₂O₃Efforts for composition that do not contain are first three-component system (20 mol% Sb₂O₃-50 mol% V₂O₅-30 mol% P₂O₅) Start by representing the sealing frit composition of the basic OLED device, and make the composition a two-component Sb₂O₃System not including (50 mol% V₂O₅-30P₂O₅, 45 mol% V₂O₅-30 mol% P₂O₅, Or 40 mol% V₂O₅-20 mol% P₂O₅Simplified to either), water resistance, flow, glass transition temperature (T)_g), And the remaining components were identified from the viewpoint of laser encapsulation. Candidate frit composition water resistance, laser encapsulation, and flow are Sb₂O₃It was needed to be comparable to the containing control sample, but T_gRequirements have been relaxed, T_gHad a criterion that must be 400 ° C or less (T)_gA frit of&gt; 400 ° C is unlikely to be sufficiently fluid during the subsequent steps of pre-sintering the OLED frit that can be handled). Antimony (Sb₂O₃) Was investigated as a potential alternative: WO₃, MoO₃, TeO₂, Bi₂O₃, Fe₂O₃, And TiO₂.. ZnO-V₂O₅-P₂O₅Considering the results of poor tolerance obtained with the frit of, ZnO is T_gIt was thought that it was only a small amount of components (5 to 10%) to reduce and maintain the flow, but ZnO was also investigated. The various oxides selected are V₂O₅It was selected because it formed a stable binary glass containing.

All of the compositions investigated are melted, poured as a glass putty, then ground in a ball mill to create a fine particle frit (typically d).₅₀= 3 ~ 5 μm) was formed. An important bench test for screening different compositions is to prepare and bake different frit flow buttons (button-shaped pieces for measuring flow properties) and evaluate their water resistance. It was. Flow buttons range from 400 to 450 ° C (T)_gAnd depends on the crystallization tendency) N₂Baked below. After firing, the flow buttons were immersed in deionized water at 90 ° C for 48 hours and their water resistance was evaluated. A control sample of OLED frit (either the base glass of D1 or a mixture of the base glass and β-eucryptite filler at 70:30) was also included in each evaluation. Surveyed Sb₂O₃Of the substitutability of (see above), TiO₂And Fe₂O₃Only seemed promising.

WO₃, MoO₃, WO₃+ ZnO, Bi₂O₃, And TeO₂As the third ingredient, 50 mol% V₂O₅-30 mol% P₂O₅The results of the composition series of are shown in Tables 1 and 2. Data for D1, the standard OLED base glass, is also shown as a comparative standard. All compositions (in mol%), injection molded glass quality, DSC glass transition temperature (T)_g), Press by hand into the shape of the pellet, at 400 ° C for 1 hour, N₂The flow and sinterability of the 3 μm powder (flow button) fired below, and the water resistance in the water resistance bench test described above (determined by the color of the supernatant of the fired flow button sample; the color is The darker the sample, the lower the resistance of the sample). Potential Sbs listed in Tables 1 and 2₂O₃All alternatives are Sb₂O₃Acceptable level of glass quality, T_g, Flow, and water resistance (90 ° C deion H₂Note that after 48 hours in O, no) occurred (judged by the appearance of the supernatant).<tables num="1"><img id="000002" he="126" wi="144" file="JP5284480B2_D0001.tif" img-format="tif" img-content="drawing" /></tables><tables num="2"><img id="000003" he="90" wi="156" file="JP5284480B2_D0001.tif" img-format="tif" img-content="drawing" /></tables>

Sb₂O₃Fe₂O₃And / or TiO₂By substituting with Sb₂O₃More positive results were obtained for vanadium phosphate frit containing no (see Tables 3 and 4). All compositions are expressed in mol%. Fe₂O₃+ TiO₂Some combinations of the above produced good glass upon injection. High TiO such as D8₂Glass (ie 25%) is acceptable T_gAnd had flow characteristics, but showed poor water resistance. High Fe such as D7 and D11₂O₃Glass (ie 25 or 30%) tended to produce defective glass upon injection, as evidenced by substantial surface devitrification. These glasses, which are relatively poorly stable (suggested by the large amount of surface devitrification formed on the putty upon injection), result in poor flow as a frit. They also tend to be unstable with respect to the oxidation state, and calcined flow buttons obtained from the same lot of powder are black (reduced) or red (oxidized) after the same calcining conditions. Either appeared alternately. Relatively high Fe₂O₃And TiO₂Glass D14 with levels is also included in Table 4, but 10 mol% ZnO is Fe.₂O₃Expected from T_gReduced the rise of. High Fe₂O₃The second attempt to match the level is V₂O₅Note that it is to increase the content. However, higher V, as seen in D9 and D10₂O₅In terms of content, water resistance was poor.<tables num="3"><img id="000004" he="117" wi="157" file="JP5284480B2_D0001.tif" img-format="tif" img-content="drawing" /></tables><tables num="4"><img id="000005" he="103" wi="159" file="JP5284480B2_D0001.tif" img-format="tif" img-content="drawing" /></tables>

25 mol percent or more P₂O₅The test samples in Tables 3 and 4 with levels performed poorly, but less than 25 mol% P₂O₅Also note that the level ones are expected to work well. Fe with 10% ZnO₂O₃And TiO₂The results of the second set of melts are summarized in Table 5. All compositions are expressed in mol%. For the first series, Fe₂O₃Because it contributes to excellent water resistance (high T)_gAnd at the cost of reduced frit sintering at 400 ° C), Fe₂O₃And TiO₂Some combinations of are preferred, TiO₂As a result, the lower T_gAnd produced an improved flow (however, water resistance was sacrificed).<tables num="5"><img id="000006" he="87" wi="159" file="JP5284480B2_D0001.tif" img-format="tif" img-content="drawing" /></tables>

An additional series of melts was added to higher levels of [Fe, while maintaining ZnO at 5 mol%.₂O₃+ TiO₂] (See Tables 6 and 7 below). All compositions are expressed in mol%. High Fe₂O₃Higher T in glass_gNote that the flow was evaluated at 425 ° C instead of the previously used 400 ° C to provide.<tables num="6"><img id="000007" he="89" wi="159" file="JP5284480B2_D0001.tif" img-format="tif" img-content="drawing" /></tables><tables num="7"><img id="000008" he="95" wi="159" file="JP5284480B2_D0001.tif" img-format="tif" img-content="drawing" /></tables>

Fe not much higher than 20 mol%, as seen in the previous results shown in Tables 1, 2 and 3 and 4.₂O₃At levels (eg about 25 mol%), high T during sintering at 400-425 ° C_gThe result was poor stability and frit with unacceptable flow. Similarly, TiO not much higher than 20 mol%₂At (eg about 25%), an acceptable T_gThe result was a frit that had flow, flow, and stability, but had unacceptable water resistance. Fe in the range of less than about 10-25 mol%₂O₃Levels, and TiO in the range of less than about 15-25 mol%₂Frit with a level (5-10 mol% ZnO) is acceptable flow, T_g, And glass stability, as well as excellent water resistance.

(Fe₂O₃+ TiO₂+ ZnO) Sb₂O₃Does not include V₂O₅-P₂O₅ The water resistance of the frit is Sb₂O₃It was found to be comparable to or slightly superior to the standard composition containing. Sb₂O₃Unexpected results in experiments that do not include Fe₂O₃ At higher levels, (Fe₂O₃+ TiO₂₊The coefficient of thermal expansion (CTE) of the ZnO) frit is significantly reduced. Shown in Attached Figure 2 is the CTE data for sintered frit with the compositions shown in Tables 3, 4 and 5. The data are 20 mol% (Fe) in Tables 3 and 4.₂O₃+ TiO₂) Series (Curve 120) and 35 mol% (Fe) in Table 5.₂O₃+ TiO₂) Series (Curve 122) are presented for all sinterable frit. CTE data for sintered frit bars is Fe₂O₃Plotted as a function of levels, up to 20 mol% Fe in each series₂O₃Is a clear upper limit for achieving a frit with good sinterability and oxidative stability. CTE value is 0 mol% Fe₂O₃/ Maximum TiO₂Highest at (20 and 35 mol% respectively), essentially Fe₂O₃60 ~ 65 × 10 regardless of level increase^-7It becomes constant at / ° C and Fe₂O₃Substantially reduced at&gt; 15 mol% (5 mol% and 20 mol% TiO respectively)₂), 17.5 ~ 20 mol% Fe₂O₃About 40 x 10^-7Note that the value of / ° C is reached. By comparison, Sb₂O₃The CTE of the contained base frit is about 70-80 x 10^-7/ ° C.

Sb₂O₃Frit and Sb including₂O₃A further direct comparison of Frit CTEs that do not contain is shown in Figure 3. Figure 3 shows the CTE curves for D1 under heating and cooling conditions (curves 124 and 126, respectively) and the CTE curves for D29 under heating and cooling conditions (remelting D24, Table 7) (curves 128 and 130, respectively). It is plotted. Approximately 40x10 of unfilled frit^-7Using a CTE value of / ° C, the CTE value of this frit can be reduced to approach the CTE value of molten silica by the addition of a filler such as β-eucryptite.

Laboratory-scale water resistance results for Sb-free frit were supported in large-scale sealing tests involving exposure of laser-sealed samples to 85 ° C / 85% RH. Standard OLED frit (D1, Table 1; low CTE filler β-eucryptite mixed at 70:30) and Sb-free frit (D29, D24 remelt, Table 7; low CTE filler) Table 8 shows the results of experiments and comparisons (used by mixing with β-crystal at 80:20 weight). Make a paste of each frit mixture and make several EAGLE^XGApplied to display glass and pre-sintered (Sb-containing standard, 325 ° C for 2 hours, air + 400 ° C for 1 hour, N₂Sb-free, 2 hours at 325 ° C, 1 hour at + 425 ° C, N₂), EAGLE^XGThe sheet was sealed and placed in an 85 ° C / 85% relative humidity environment chamber, and then regular observations were made for evidence of sealing leaks and Ca metal breakage. In total, the study included a control composition containing 3 Sbs and 7 antimony-free compositions, each with 9 rows of sealed Ca metal tabs. As can be seen in Table 8, for both Sb control frit and Sb-free frit, several rows were damaged immediately after encapsulation or within 100 hours of placement in an 85 ° C / 85% RH chamber; These defects were probably related to gross defects such as contamination that were irregularly present on each frit. However, after 96 hours, no further defects were found in the encapsulation of the Sb control frit or Sb-free frit.<tables num="8"><img id="000009" he="62" wi="159" file="JP5284480B2_D0001.tif" img-format="tif" img-content="drawing" /></tables>

In summary, flow and glass transition temperature (T)_g) Is added in a small amount and Sb₂O₃Antimony oxide Fe₂O₃+ TiO₂By substituting with the combination of Sb-vanadium phosphate frit, the excellent water resistance was maintained. Fe₂O₃It was found that the presence of was most effective in improving tolerance. However, in large quantities, T_gRaises and exacerbates the flow of frit during sealing. In addition, high Fe₂O₃Frit with levels (approximately 25 mol% or higher) tend to be oxidatively unstable and have the same schedule of samples (N).₂Below, repeated firing at 425 ° C) showed different colors (brown or black), showing significant differences in the degree of flow. TiO₂Actually reduced the water resistance to some extent when added alone, but (Fe₂O₃+ TiO₂) Combinations are high water resistance and low T_gIt looked like an ideal combination in terms of providing a laser encapsulating frit with both (400 ° C). Labbench tests in 90 ° C distilled water and 85 ° C / 85% relative humidity (RH) environmental chamber tests of laser-sealed samples are both Fe.₂O₃-TiO₂-ZnO-V₂O₅-P₂O₅It is suggested that the system-based frit can form a tight seal after laser encapsulation, which can withstand high humidity conditions for a long time ( 1000 hours). Sb₂O₃(Fe₂O₃+ TiO₂The unexpected result of replacing with) is that the CTE of the frit without filler and without Sb is T._gApproximately half (70-80 × 10) with a slight rise (from 355 ° C to 370 ° C)^-735 ~ 45 × 10 from / ° C^-7It had dropped to / ° C). 40 × 10^-7Frit with a CTE value close to / ° C has the potential to seal fused silica substrates and other low CTE substrates such as Kovar with the addition of fillers such as β-eucryptite. ..

Although some embodiments of the present invention have been illustrated in the accompanying drawings and the detailed description described above, the present invention is not limited to the disclosed embodiments and is described in the appended claims. It should be understood that many rearrangements, modifications, and replacements are possible without departing from the spirit of the invention as defined.