JP2001261369A - Low melting point glass composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a zinc phosphate-based low melting point glass for covering the surface of a substrate directly, or covering a conductor-semiconductor pattern arranged on the substrate, and for sticking the substrate to other members, and substantially free from PbO, Bi2O3 and alkali metal oxide. SOLUTION: This low melting point glass composition has a glass composition comprising 45-66 wt.% P2O5, 0-10 wt.% Al2O3, 0-10 wt.% B2O3, 0-5 wt.% MgO, 0-11 wt.% CaO, 0-18 wt.% SrO, 0-26 wt.% BaO and 10-30 wt.% ZnO regulated so that the weight ratio of (Al2O3+B2O3)/P2O5 may be within the range of 0.05-0.25, and substantially free from lead component, bismuth component and alkali metals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zinc phosphate system for directly covering the surface of a substrate, insulatingly covering conductors and semiconductor patterns disposed on the substrate, or bonding the substrate and other members. It relates to a low-melting glass substantially free of PbO, Bi ₂ O ₃ and alkali metal oxides.

[0002]

2. Description of the Related Art Conventionally, lead-based glass has been adopted as low-melting glass, for example, low-melting glass for coating a substrate. Although the lead component is an important component for lowering the melting point of glass, it has a serious adverse effect on the human body and the environment, and has recently been tending to avoid its use. Separately, when forming a low-melting glass, it is known that alkali metals, bismuth components, tellurium components, etc. are introduced into the glass, but the alkali metals are easily leached on the glass surface, and the electrical insulation property is reduced. In the electronics field, it tends to be avoided because of its lowering. The fact that the bismuth component and the tellurium component are also heavy metals similar to lead has an undeniable effect on the environment.

[0003] With regard to the known art, for example,
-87531, JP-A-5-132339, JP-A-8-1
No. 83632 discloses a zinc phosphate-based low-melting glass containing an alkali metal, but as described above, the alkali metal is easily leached out of the glass surface, and also reduces the electrical insulation, so that particularly the electronics It is shunned in the field.

Further, for example, Japanese Patent Application Laid-Open No. 10-29835 discloses a non-alkali zinc phosphate-based low-melting glass, in which tungsten oxide is essential.
It has a high melting point and is not an effective component for obtaining a low melting point glass.

[0005] Separately, Japanese Patent Application Laid-Open No. 11-314936 discloses a zinc phosphate-based low-melting glass which requires tin oxide (II) as an essential component. Its presence requires glass production and deposition in an inert or reducing atmosphere, and is not practical or industrially appropriate.

Many of these prior arts have low or no barium oxide content as in the present invention, but barium oxide facilitates glass melting, lowers glass viscosity, makes the thermal expansion coefficient moderate, and It is an effective component having various advantages, such as not deteriorating the water resistance of glass such as alkali metals, leaching on the glass surface, and lowering the electrical insulation.

The present invention solves the disadvantages of the prior art, directly covers the surface of the substrate, or insulates a conductor or semiconductor pattern disposed on the substrate, or forms a phosphor for bonding the substrate and other members. An object of the present invention is to provide a low-melting glass which is zinc-acid-based and substantially does not contain PbO, Bi ₂ O ₃ and alkali metal oxides.

[0008]

According to the present invention, the glass composition is expressed by weight% of P ₂ O ₅ 45-66, Al ₂ O ₃ 0-10, B ₂ O ₃ 0-10,
MgO 0-5, CaO 0-11, SrO 0-18, BaO 0-26, Zn
O 10-30%, (Al ₂ O ₃ + B ₂ O ₃ ) / P ₂ O ₅ weight ratio 0.05-0.2
The low melting point glass composition is substantially in a range of 5 and does not substantially contain a lead component, a bismuth component, and an alkali metal.

In the above, the coefficient of thermal expansion at 30 to 300 ° C. is 6
0 to 90 × 10 ⁻⁷ / ° C., with a thermal expansion deformation point of 570 ° C. or less.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a substrate in the present invention, a transparent glass substrate, in particular, a soda-lime-silica glass or a glass similar thereto (high strain point glass) is generally used. Approx. 70-90 × 10 ^-7 /
° C, and the low-melting glass of the present invention is made to be close to that, thereby preventing adverse effects such as peeling of the formed film and warping of the substrate. Further, while the thermal expansion deformation point of the glass substrate is substantially 620 or more, that of the low-melting glass of the present invention is sufficiently low as 570 ° C. or less,
The baking temperature can be lowered accordingly, and the softening deformation and heat shrinkage of the substrate during baking can be suppressed.

In the present invention, by making the glass component zinc-based, the above physical properties can be satisfied and Pb
By not including O and Bi ₂ O ₃ , there is no effect on the human body and the environment. Further, by not containing an alkali metal oxide, the coating film is excellent in electrical insulation properties and does not cause any adverse effects due to alkali leaching from glass, so that it is suitable for use in electronic materials and the like.

The low-melting glass of the present invention is used not only for insulatingly coating conductors and semiconductor patterns disposed on a substrate, but also for cases where a film is formed directly on the substrate surface, for example, for suppressing alkali leaching of an alkali-containing glass substrate. The present invention can also be applied to the case where the optical characteristics of a glass substrate are changed or other various functional films are formed. Further, it is effective in bonding the substrate to another metallic or ceramic material. Alternatively, when a glass substrate is coated with a low-melting glass powder mixed with silica fine powder, alumina fine powder, or the like as appropriate, a frosted glass that reduces glare caused by solar radiation or illumination can be used, and thus has a wide application range.

The composition of components in the low-melting glass is in the following range. P ₂ O ₅ is an important glass-forming component, and is contained in the glass in the range of 40 to 66% (expressed by weight%, the same applies hereinafter). If it is less than 40%, the glass formation becomes unstable,
Heat treatment causes devitrification. If it exceeds 66%, the softening point rises excessively.

Al ₂ O ₃ gives the glass an appropriate coefficient of thermal expansion and softening point, and is contained in the glass in a range of 10% or less as necessary. If it exceeds 10%, the coefficient of thermal expansion becomes too small.

B ₂ O ₃ is a glass-forming component and facilitates melting of the glass and gives the glass an appropriate coefficient of thermal expansion.
If it exceeds 10%, the glass becomes unstable and tends to be immiscible with P ₂ O ₅ in the above content range.

Further, the weight ratio of (Al ₂ O ₃ + B ₂ O ₃ ) / P ₂ O ₅ in the glass is in the range of 0.05 to 0.25. When the ratio is less than 0.05, the thermal expansion coefficient and the softening point are adjusted to appropriate ranges. When it exceeds 0.25, there are many disadvantages such as an excessive increase in softening point, precipitation of devitrification, and sometimes immiscibility in glass.

In consideration of the thermal expansion coefficient, the softening point, the glass melting property, and the dialysis loss property, P ₂ O ₅ + Al ₂ O
₃ + B ₂ Total O ₃ is desirably in the range of 50% to 75%.

ZnO lowers the softening point of the glass and imparts appropriate fluidity. In general, in a phosphate glass structure having a large coefficient of thermal expansion, Zn ions are intervened to reduce the coefficient of thermal expansion to an appropriate level. It is contained in the range of 10 to 30%.
If it is less than 10%, the above effect cannot be exerted, and particularly, the thermal expansion coefficient of glass becomes excessive. If it exceeds 30%, glass formation becomes difficult.

BaO lowers the softening point of glass, imparts appropriate fluidity, and adjusts the thermal expansion coefficient to an appropriate range. BaO is contained in the glass in the range of 0 to 26%. If it exceeds 26%, the coefficient of thermal expansion increases excessively. Preferably, it is in the range of 5 to 26%.

Of the divalent metal components other than those described above, MgO is contained in the range of 0 to 5%, CaO is contained in the range of 0 to 11%, and SrO is contained in the range of 0 to 18%, so that the glass viscosity and softening point are increased. Is adjusted appropriately, and the coefficient of thermal expansion is adjusted appropriately. In any case, if the ratio exceeds the above range, glass formation becomes difficult, or the coefficient of thermal expansion may be out of an appropriate range.

If the amounts of PbO, Bi ₂ O ₃ and alkali metal oxides are such that they are mixed as impurities in the glass raw material or cullet, and each is within the range of 0.3% or less in the low melting point glass, the above-mentioned harmful effects are obtained. That is, the effects on the human body and the environment,
There is almost no effect on insulation characteristics and the like.

Further, depending on the use of the low melting point glass, Fe may be used for coloring the glass within the range not deteriorating the above-mentioned properties, or for imparting the ultraviolet absorbing performance, the infrared shielding performance and the like.
₂ O ₃ , Cr ₂ O ₃ , CoO, TiO ₂ , CeO _{2 and the} like can be added, but the total of these added components should be 1% or less.

[0023]

[Example] [Preparation of low melting point glass] Phosphoric acid as a P ₂ O ₅ source, boric acid or boron phosphate as a B ₂ O ₃ source, Al ₂ O
_Using aluminum oxide or aluminum metaphosphate as a source, zinc white as a ZnO source, barium carbonate as a BaO source, magnesium carbonate as a MgO source, calcium carbonate as a CaO source, and strontium carbonate as a SrO source. After mixing to obtain a desired low-melting glass composition, the powdery raw material was charged into a platinum crucible, and phosphoric acid as a liquid raw material was dropped to cause a reaction. After heating in an electric heating furnace at 400 to 500 ° C for 1 to 2 hours to terminate the reaction,
After heating and melting at 1000 to 1100 ° C. for 1 to 2 hours in an electric heating furnace, the mixture is poured onto a carbon plate and gradually cooled to obtain glasses having compositions shown in Examples of Tables 1 to 5 and Comparative Examples. Was.
The glass samples were subjected to the following tests.

[Measurement of Thermal Expansion Coefficient] A glass sample was cut and polished to a predetermined size (20 × 4 mmφ), set on a differential thermal dilatometer, and heated at a rate of 5 ° C./min to measure the amount of elongation. Measured and recorded, the average coefficient of thermal expansion α (× 10 ^-7 /
° C) was calculated. The test load was 5 gf.

[Measurement of transition point and softening point (thermal expansion yield point)] The transition point (Tg (° C.)) and the softening point (T _yield (° C.)) which is the thermal expansion _yield point are measured from the above thermal expansion data. did. For reference, a glass beam of a specified thickness and dimensions was prepared for some glass samples, set in a Littleton viscometer, and heated to a temperature at a glass viscosity of ^107.6 poise, that is, the Littleton softening point (simply the softening point). Or Littleton point: T _{s oft} (° C.).

[Measurement of Crystal Precipitation Temperature, Measurement of Crystal Precipitation Temperature-Transition Point] A finely pulverized glass sample was set in a differential thermal analyzer, and the temperature was raised to 1000 ° C. at a rate of 10 ° C./min to absorb heat and generate heat. The peak was measured and recorded. Among these, the exothermic peak based on the crystal precipitation was defined as the crystal deposition temperature (Tc (° C.)), and the presence or absence of the crystals was confirmed under a magnifying glass. From the value obtained by subtracting the transition point (Tg) from the crystal precipitation temperature (Tc), a temperature difference between the crystal precipitation temperature and the transition point: Tc−Tg (° C.) was calculated. The larger the value of Tc−Tg (° C.), the less the devitrification precipitation and the opacity of the glass occur during the heat treatment above the transition point, indicating that Tc−Tg (° C.) ≧ 200 (° C.). Is preferred.

[Results] The results of various tests are shown in Tables 1 to 5.

As is clear from Tables 1 to 5, the examples according to the present invention have an appropriate glass thermal expansion coefficient, a low softening point (thermal expansion yielding point), a transition point, and a melting-cooling process. Is difficult to precipitate even during heat treatment and re-heat treatment, and P ₂ O ₅ −B ₂
There is no immiscibility of O ₃ , and it is very effective in coating a substrate, especially a glass substrate, coating a conductor pattern on the substrate, and bonding the substrate to other materials. On the other hand, the comparative example cannot satisfy the above thermophysical properties.

[Table 1] Example 1 2 3 4 5 6組成 Composition P ₂ O ₅ 64.7 63.8 61.2 58.7 59.5 59.9 wt% Al ₂ O ₃ 9.3 9.1 8.8 8.4 4.3 2.2 B ₂ O ₃ ----2.9 4.4 A + B * 1 9.3 9.1 8.8 8.4 7.2 6.6 P + A + B Total * 1 74.0 72.9 70.0 67.1 66.7 66.5 MgO 3.7-----CaO-5.1----SrO--8.9---BaO ---12.7 12.9 12.9 ZnO 22.3 22.0 21.1 20.2 20.4 20.6 RO total * 2 26.0 27.1 30.0 32.9 33.3 33.5 Total 100 100 100 100 100 100 (A + B) / P weight ratio * 1 0.144 0.143 0.144 0.143 0.121 0.110 α (30-300 ℃) 60 64 69 74 78 86 Tg (℃) 470 470 476 479 484 481 Tc-Tg (℃) * 3 ∞ ∞ ∞ ∞ ∞ ∞ _yield T _yield (℃) 532 534 518 530 537 538 T _soft (℃: 10 ^7.6 P) − − − 588 − 602 ──────────────────────────────────── Note * 1: A represents Al ₂ O ₃ , B represents B ₂ O ₃ , and P represents P ₂ O ₅ (see Tables 2 to 5). The same). * 2: RO is a general term for MgO, CaO, SrO, BaO, and ZnO (the same applies to Tables 2 to 5). * 3: In the Tc-Tg (° C) data, ∞ indicates that no crystallization peak was detected by differential thermal analysis and no crystal precipitation was found by microscopic observation (also in Tables 2 to 5). Similar). In the physical property data,-is not measured (the same applies to Tables 2 to 5).

[Table 2] Example 7 8 9 10 11 12 ─ composition _{P 2 O 5 62.4 60.3 55.4 60.1} 65.3 46.9 _{wt% Al 2 O 3 9.0 - 8.0} 8.6 9.4 2.7 B 2 O 3 - 5.9 - - - 6.2 A + B * 1 9.0 5.9 8.0 8.6 9.4 8.9 P + A + B Total 71.4 66.2 63.4 68.7 74.7 55.8 MgO-----1.9 CaO----10.3-SrO---17.5--BaO- -13.0 23.9--20.5 ZnO 28.6 20.8 12.7 13.8 15.0 21.8 RO total 28.6 33.8 36.6 31.3 25.3 44.2 Total 100 100 100 100 100 100 (A + B) / P weight ratio 0.144 0.098 0.144 0.143 0.144 0.190 α (30-300 ℃) 60 85 87 80 71 81 Tg (℃) 450 471 502 499 499 520 Tc-Tg (℃) ∞ ∞ ∞ ∞ 228 228 T _yield (℃) 495 529 548 550 552 566 566 T _soft (℃: 10 ^7.6 P) − − − − − − ────────────────────────────────────

[Table 3] Example 13 14 15 16 17 18組成 Composition P ₂ O ₅ 55.3 59.1 50.2 50.5 53.7 47.5 wt% Al ₂ O ₃ 2.2 6.4 2.3 2.1 2.1 B ₂ O ₃ 4.5 1.5 6.2 4.6 4.4 4.4 A + B 6.7 7.9 6.2 6.9 6.5 6.5 P + A + B Total 62.0 67.0 56.4 57.4 60.2 54.0 MgO--1.8---CaO------SrO------BaO 13.3 12.7 20.3 13.6 19.3 25.6 ZnO 24.7 20.3 21.5 29.0 20.5 20.4 RO total 38.0 33.0 43.6 42.6 39.8 46.0 Total 100 100 100 100 100 100 (A + B) / P weight ratio 0.121 0.134 0.124 0.137 0.121 0.137 α (30-300 ° C) 79 76 86 77 88 90 Tg (° C) 469 480 501 462 460 491 Tc-Tg (° C) ∞ ∞ ∞ ∞ ∞ 243 T _yield (° C) 518 530 540 509 509 558 558 T _soft (° C: 10 ^7.6 P) − 594 − − − − ─── ─────────────────────────────────

[Table 4] Comparative Example 1 2 3 4 5 ──────────────────────────────── Composition P ₂ O ₅ 53.3 51.4 40.0 52.5 58.9 wt% Al ₂ O ₃ 9.6-9.6 7.5 8.5 B ₂ O ₃ 6.5 12.6 13.1--A + B * 1 16.1 12.6 22.7 7.5 8.5 P + A + B Total 69.4 64.0 62.7 60.0 67.4 MgO-----CaO-----SrO----25.8 BaO-13.9 14.4 34.0-ZnO 30.6 22.1 22.9 6.0 6.8 RO total 30.6 36.0 37.3 40.0 32.6 Total 100 100 100 100 100 (A + B) / P weight ratio 0.302 0.245 0.568 0.143 0.144 α (30-300 ° C) − 76 − − − Tg (° C) − 529 − − − Tc-Tg (° C) − 178 − − − T _yield (° C) − 583 − − − T _soft (° C: ^107.6 P) − − − − − Remarks Crystallization Immiscible Immiscible Immiscible ──────────── ────────────────────

[0033]

[0034]

According to the present invention, the glass has an appropriate glass thermal expansion coefficient, a low softening point (thermal expansion yielding point), and a transition point, and hardly causes devitrification even in a melting-cooling process or a re-heat treatment.
There is no immiscibility of P ₂ O ₅ -B ₂ O ₃ , and it has a remarkable effect in coating a substrate, particularly a glass substrate, coating a conductive pattern on the substrate, and bonding the substrate to other materials.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Machishita 1510 Oguchicho, Matsusaka-shi, Mie Central Glass F-term in Glass Research Laboratories Co., Ltd. 4G062 AA08 AA09 AA11 BB09 DA01 DB01 DB02 DB03 DC01 DC02 DC03 DD05 DD06 DE04 DF01 EA01 EA10 EB01 EC01 ED01 ED02 ED03 EE01 EE02 EE03 EE04 EF01 EF02 EF03 EF04 EG01 EG02 EG03 EG04 FA01 FA10 FB01 FC01 FD01 FE01 FF01 FG01 FH01 FJ01 FK01 FL01 GA01 H01 H01 H01 H01 H01 H JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM07 NN26 NN32 5E314 AA10 AA11 GG21 GG26

Claims (2)

[Claims] (1) A glass composition having a weight percentage of P_TwoO_Five 45-66, Al_Two
O_Three 0-10, B_TwoO_Three 0-10, MgO 0-5, CaO 0-11, Sr
O 0-18, BaO 0-26, ZnO 10-30%, (Al_TwoO_Three+ B
_TwoO_Three) / P _TwoO_FiveWeight ratio in the range of 0.05 to 0.25, substantially
Contains lead, bismuth, and alkali metals
A low-melting glass composition characterized by being free of glass. 2. The thermal expansion coefficient at 30 to 300 ° C. is 60 to 90 × 10 ^-7 /
The low-melting glass composition according to claim 1, wherein the low-melting glass composition has a thermal expansion deformation point of 570 ° C or lower.