JPS6046946A - Ultraviolet light transmission glass - Google Patents

Abstract

PURPOSE:The titled glass having a low melting temperature, a low molding temperature, and properties required for window glass of FPROM element, consisting of CaO, Al2O3, B2O3, and SiO2, having a specific Fe2O3 content. CONSTITUTION:Ultraviolet light transmission glass consisting of 8-54wt% CaO, 6-35wt% Al2O3, 20-60wt% (CaO+Al2O3), 3-60wt% B2O3, 5-67wt% SiO2, 40-75wt% (B2O3+SiO2), 90-100wt% (CaO+Al2O3+B2O3+SiO2), 0-10wt% R2O (Li2O+Na2O+Rb2O+Cs2O), 0-10wt% R'O (BeO+MgO+SrO+BaO+ZnO), 0-2wt% R''2O3 (As2O3+Sb2O3), 0-5wt% P2O5, and 0-10wt% (R2O+R'O+ R''2O3+P2O5), having <=0.03wt% Fe2O3, 40X10<-7>-75X10<-7>/K average coefficient of linear expansion at 25-30 deg.C, >=40% ultraviolet light transmittance at lambda=2,537nm wavelength at 3.7mm. thickness of test sample, and improved weather resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to ultraviolet transmitting glass, especially ultraviolet erasable EPRO.
M element (Electric programmable
The present invention relates to an ultraviolet transmitting glass suitable for windows of ReadOn 1 yMemOry.

Conventionally, a sapphire plate, ultraviolet-transmitting glass, or the like has been used for the window of an EPROM element. The characteristics required of the window material for these EPROM elements are: 0) High transmittance of light at a wavelength of 2537 nm from a mercury lamp, which is normally used as a light source for erasing. ■Thermal expansion coefficient of polycrystalline alumina (J7X1
It has a coefficient of thermal expansion that is not significantly different from 0-7//. ■Good weather resistance. etc. Currently, ultraviolet-transmissive glass is often used in terms of productivity and cost.

The glass currently in common use is approximately S by wt%.
io2g, s%, B2O3, 22, 1%, Al120
3! ;, 0%cao 0.5%, Li2O0,g%,
Na2O2,l-! ;%: AS203 0.4% This glass has a higher viscosity than ordinary glass, with priority given to its ultraviolet transmission properties.

The high viscosity of glass (that is, the high melting temperature) is not only disadvantageous in terms of energy consumption, but also the quality of glass deteriorates due to the contamination of impurities due to erosion of the refractory (for example, genuine purple). The first drawback of IAm transparent glass is that the refractory material is limited. Furthermore, when conventional glass is attached to an alumina substrate as a window glass for an EPROM element, it is heated to about 1000°C (the temperature at which the viscosity of the glass becomes itogy) and pressed together. Systems with a high temperature of approximately 1000°C are used as crimping terminals without the disadvantage of requiring a large amount of heating time and energy. It had the disadvantage of early damage.

In general, the ultraviolet transmission characteristics of glass are determined by two factors: ultraviolet absorption due to impurities such as trivalent iron ions in the main glass glass and platinum ions dissolved into the glass from a platinum crucible, and ultraviolet absorption due to the glass structural characteristics. Depending on the species, the presence of impurities has made it difficult to develop new UV-transparent glass compositions.

The present invention provides a new glass that inherently has low ultraviolet absorption based on the structure of the glass, and an object of the present invention is to provide a new glass that has a low melting temperature, a high molding temperature, and an EPRO
The objective is to provide glass with appropriate performance (ultraviolet transmission characteristics, coefficient of thermal expansion, weather resistance) required as window glass for M elements.

The ultraviolet transmitting glass of the present invention has CaOZA1203 of 6 to 3% by weight. ; CaO+Al2O320-60 B203 3~OtsuQ Si02! ;~ Otsu 7 B203+5i02 Ilo~ 7I CaO+Al2O3 B2O3+5i02 qO-10
O and Fe2O3 is 0.03% by weight or less, particularly preferably in weight% /2 CaO-~, 27 AA203 Kuzu~21 ≧1 0aO+Al2O33≠"-11g 1<B2O3 station~30 U〇 9 8102~-6'7 B203 +5i02 s, x~i (:aO+Ad203+B2O3+5i02 90~/
OO and Fe2O3 is 0.03% by weight or less.

The reasons for limiting the composition to the above are described below.

I cao+p, 12o3-20-40% (preferably W
-11-g%> is the reason why OaO+Al2O3
and cao +Ajl! When the content of 203 is less than each limit value, (1) the glass becomes more likely to devitrify. ■This is due to drawbacks such as deterioration of water and acid resistance. Also cao + A
As the content of 12':'s and OaO + Al2O3 increases, the absorption edge of the ultraviolet transmittance of the obtained glass moves to the longer wavelength side compared to the original absorption edge position as the content ij8 increases. This reduces the glass's essential UV transmission properties. ■As the content increases, the thermal expansion coefficient of the obtained glass increases and deviates from the desired value of the thermal expansion coefficient.If the content exceeds each limit value, the glass targeted by the present invention cannot be obtained. do not have.

Second, B2O3, together with S]02, is an essential component of the glass-forming oxide in the glass of the present invention, and functions to lower the melting temperature of the glass. This reduction in melting temperature leads to a reduction in melting energy and helps to obtain an lj glass that is less contaminated with impurities that may impede UV transmission from crucible compatibility and the like. Also, B2
O3 can be contained in a relatively large amount because its essential ultraviolet absorption edge in glass has a short wavelength.

B2O3 content is 3 to Oa% (preferably → to 30%)
is within the range of B when the content of B2O3 is less than 3%
The effect of adding 2O3 becomes less noticeable, and if the content is higher than O%, the weather resistance of the crow that gets scratched becomes worse.

Inclusion of 5i02 in the glass results in (1) the essential purple color of the component in the glass, and the absorption edge of the glass having a short wavelength. ■It is a typical glass-forming oxide, and has the effect of widening the vitrification range and improving water and acid resistance with good Qj. The content of 5102 is important. The reason for limiting the
At 3-% or less, the effect of adding Sj,02 becomes less noticeable, and this is because the water resistance deteriorates. If it is more than 7%, the water and acid resistance will improve, but it will require a lot of melting and mixing without melting the glass. This is because it becomes difficult to manufacture a glass with high light transmittance. The content of B2O3+5i02 is 1. The reason for limiting it to ~975% (preferably 3.2~H%) is as follows:
If it is less than 1Io%, other components will relatively increase, so ■
This is due to drawbacks such as deterioration of the essential ultraviolet transmission properties of the glass; (2) an excessively large coefficient of thermal expansion; On the other hand, if the content is 7S% or more, it is good in terms of essential ultraviolet transmission properties, but ■The glass becomes susceptible to devitrification■
CaO+Al2O3+B2O3+5i02 is 90 to 10, which is due to drawbacks such as the coefficient of thermal expansion becoming too low.
It is 0%. CaO + Al2O3 ten B2o3 + 5io2
When the content is less than 90%, Ca, O+ A
The effects of the components other than 1203rB2O3 and 5IQ2 are so great that it is impossible to obtain a glass that has the ultraviolet transmittance and thermal expansion coefficient and is easy to melt as the object of the present invention. Furthermore, the glass of the present invention has a high ultraviolet transmittance, and if the concentration of common impurities becomes high, the purpose of the present invention will be lost. Among impurities, the Fe2O3 concentration in particular has a significant deterioration in quality with respect to ultraviolet transmittance, and its concentration is 0.
Must be less than 0.03%.

Furthermore, the glass of the present invention contains R20 (Li2O, Na2O, R20, Rb2) within a range that does not impair its basic properties.
O.

R”203 (AS203, 5b203) Components such as lP2O5 can be added.The weight range that can be added is R2
0 (Li20 + Na2O+20+Rb2O+0820
H) 0-10%, R'O(BeO+MgO+SrO+B
a, O+ZnO) 0-10%, R”203 (A120
3r3b203) 0~2%+P2O3'~loved, R20+R10-IR"2030 P2O50~IO%
is within the range of R20,! Addition of PO components has the effect of lowering the melting temperature and improving vitrification, but if the content of each in the glass is 70% or more, the ultraviolet absorption edge of the glass will shift to the wavelength 233Vnm side. Due to the movement, the UV transmission properties deteriorate. ■Problems such as an increase in the coefficient of thermal expansion may occur. A designated as R11203
S203 and S b 2 Q 3 are commonly used devoluting agents and are useful components in glass manufacturing, but if their content in glass is 2% or more, ultraviolet rays become transient. to degrade. P2O5, represented by R'''205, is a component that does not change its properties even if it is contained in a small amount in the glass of the present invention, but if it is contained in an amount exceeding 3%, ■
The disadvantage is that the devitrification of the glass increases and the coefficient of thermal expansion increases.

The total value of R20+R'O+R"2030 P2O5 is 70
%, the disadvantage is that the ultraviolet transmission properties deteriorate and the thermal expansion coefficient increases due to the combined effect of the addition effects of each component.

The glass of the present invention has an average coefficient of linear expansion of approximately tio×kuta 1O-VK to sieve X/(7-7/). Provides glass with properties of approximately 7-7/ to 7-7/.

The present invention will be described in further detail using Examples below.

Example / Glass raw material (pickled silica sand for optical glass and special grade reagent (3a)
003+Al2O3+H3BO3), the final glass composition and glass weight are Ca0.23.2 wt%, Al3
O3/za, 3wt%, B2O3/9. Owt%, 5i0
After weighing 2J, 9 wt%, soog, and adding a small amount of reducing agent and mixing, the mixture was melted for 2 hours using a platinum crucible in an electric furnace set at 1 qoo'c. After that, the glass was taken out of the furnace, poured out onto an iron plate, formed into a plate shape, and then transferred to a slow cooling furnace maintained at 700°C.
It was slowly cooled to room temperature. From the obtained sheet glass, the thickness is 3.
A sample for ultraviolet transmittance measurement with a size of 6 mm and a size of 10 mm x 30 mm and a sample for thermal expansion measurement with a size of 5 x x/jmm were obtained by cutting and polishing. Using the obtained sample for ultraviolet transmittance measurement, -2jJ
The transmittance at a wavelength of 71 m was measured using a sample for thermal expansion measurement, and the average linear expansion coefficient at 25''C to 300°C was measured using a commercially available thermal expansion measurement device.

The weather resistance test of the glass was determined based on the results of the water resistance and acid resistance tests of the glass. The water resistance and acid resistance of glass is 2S. Glass particles of 0 μm to 120 μm are prepared in a specific gravity duram of the glass, and purified water or 0
．． 0/NHNo3 solution for 1 hour at 5 occ,
The total weight of the components dissolved into the aqueous solution was determined by analysis of the aqueous solution. Here, an increase in the eluted component IRm indicates a decrease in water resistance and acid resistance and a decrease in weather resistance.

Table 2 shows the results of ultraviolet transmittance, thermal expansion coefficient, meltability evaluation, and weather resistance evaluation.

Here, in Table 2, the composition percentages of Examples are heavy weight percentages.

Fe2o3 was mixed into the glass as an impurity, but 0.
It was below 0/%. Characteristic value (a) Ultraviolet transmittance (%)
is the transmittance at a wavelength of 2337 nm with a sample thickness of 3.1 mm. Characteristic value (b) Thermal expansion coefficient is 25°C ~ 30
The average linear expansion coefficient between 0℃ is qoxto-'1/~jO
×l0-77K with @ mark! To 0XIO-77~ 9 Otsu (111X10-7/K with e mark, to×l0-VK~
= Hill X1O-7) K is classified as marked [Yes]. Characteristic values (01 Meltability: Compositions that can be melted for production below 1 aoo°C are marked with ◎, /'100~/j' O
Those that can be melted at O'C are marked with ○, 7500 to 1600
Those that can be melted at °C are classified as Δ. (
d) Regarding weather resistance, we have determined empirically based on the water and acid resistance test results, and those that are considered usable are marked with a circle, and those with particularly better weather resistance than conventional glass are marked with an ◎ mark.

Example 2~. ! 3 Magnesium + 3r co 3 + BaC03+
Znol As203 +5b203, AlPO4
) was weighed so that the final glass composition and glass weight would be the composition and soog shown in Table 2, and a small amount of reducing agent was added,
After mixing/1100°C~/! ;! Melting was carried out for 2 hours using a platinum crucible in an electric furnace set at O'C. Thereafter, the glass was taken out of the furnace, poured out onto an iron plate, formed into a plate shape, and then transferred to an annealing furnace maintained at SO°C to 720°C and slowly cooled to room temperature. A measurement sample similar to that in Example 1 was prepared from the obtained glass, and 23; 37
The ultraviolet transmittance at a wavelength of nm, the average linear expansion coefficient at 25°C to 300''C, and the weather resistance were measured.The results are shown in Table 2.Fe2O3 was mixed into the glass as an impurity, but 0.
．． It was below 0/%. In particular, Table 1 shows a comparison of the J)-physical properties of the glasses of Examples 13 and /4' and those of conventional examples.

As can be seen here, a melting temperature of 1000 to 300°C is sufficient, and the glass has a low working temperature of 900°C.

As can be seen from the above examples, the ultraviolet transmitting glass of the present invention has good ultraviolet transmittance at a wavelength of 2 and 37 nm, which is required as a window glass for an EPROM element. ■The coefficient of thermal expansion is very different from that of polycrystalline alumina material, which is the material of the window frame to which the glass is fused.

■It satisfies conditions such as good water resistance and acid resistance, and has low resistance. This ultraviolet transmitting glass is extremely suitable as window glass for EPROM devices.

/ Indication of the case Patent application 2 filed on August 79, 1937 Name of the invention Ultraviolet transmitting glass 3 Relationship to the case by the person making the amendment Patent applicant address Doshuaki-chome-za, Higashi-ku, Osaka-shi, Osaka Prefecture Name
(II-00) Nippon Sheet Glass Co., Ltd. Representative Saiga
Nobuo 1 Agent address: Shinbashi Sumitomo Building, 5-1J, Shinbashi, Minato-ku, Tokyo, Nippon Sheet Glass Co., Ltd. Special Dispatch Department Sponsored by Party B The "Scope of Claims" section of the specification to be amended and 7. Amendment Contents (1) The "Claims" of the specification will be revised as shown in the attached sheet.

(2) Line B from page 1 of the specification [0a to occur]
OJ means [to occur]. Changed to 0aOJ.

(3) Change "P2O3" in the third line from the top of page io of the specification to rP205J.

2. Scope of claims (1) In weight% cao g～qS Aa2o3 6~3S CaO+Ad203 20~t.

B2O33~Otsu0 8i02! ;~Otsu 7 B203+5i02 110~7S OaO+AA203+B2O3+5i02 90~/
O.

An ultraviolet transmitting glass for a window of an EPROM device, characterized in that Fe2O3 is 0.03% by weight or less.

(2) In weight% C1aO/7~27 A12o3 /#-2I CaO+Al2O331~4+4 B203 /l/-, 30 Si02 30~5O B203+5i02 5.2~ Otsu9 0aO+Al2O3+B2O3+5i02, 9O-
10O and Fe2O3 is o, iy 3% by weight or less, the ultraviolet transmitting glass according to claim 1.

f3) CaO, Al2O3, B2O3, and 5i0
In addition to the two components, R20 (Li20 + Na2O + 20 + Rb2O + CS
20) 0~10 R10 (BeO+MgO+SrO+Ba○+Zn0)
O~10R”203 (AS203+5b203) O~
! The ultraviolet-transmissive glass according to claim 1 or 2, comprising: p2o5 o~5 R2o+R1o+Rjj2o3+Yontotachi 0-10.

(4), 2! The average coefficient of linear expansion between 23"C and 300°C is 'l (7X/Q -'i'/ The ultraviolet transmitting glass according to claim 2 or 3, wherein the ultraviolet ray transmitting glass is 5X1O'''7/.

(6) Wavelength λ-2! ;The ultraviolet transmittance at 37 nm was measured when the sample thickness was 3. The ultraviolet transmitting glass according to any one of claims 1 to 5, which has a UV transmittance of 40% or more in II Kmm.

Claims (1)

[Claims] (At 11% by weight (3) CaOza~lS A, 7203 g~35 CaO+A120320-6O B203 3~ Otsu0 3i02 S~ Otsu7 B203+5i02 'lO-73 CraO+Al2O3+B2O3+5102 qo-1
0° and Fe2O3 is 0.03% by weight or less. 9 AAz○3 #~21 1 GaO+Al2O3fQ-Il1 9 B203+5i02 32~ Shioto CaO+Al2O3 + B2O3+5i02 q□-10
0 and Fe2O3 is 0.03% by weight or less
1. The ultraviolet transmitting glass according to item 1. CaO + Al2O3, B2O3, and 5102 components were added to R20 (Li20 + Na2O + 20 + Rb2O 105
20) 0~10 R10 (BeO+MgO+SrO+BaO+Zn0)
0-10R//203 (As20., +5b20.5
) 0~2p2o5 o~5 R20+R'O+R11203+P20:z O~10
An ultraviolet-transmitting glass according to claim 1 or 2, which includes: Is it the average coefficient of linear expansion between 2S℃ and 300℃? O×10-V
The ultraviolet transmitting glass according to claim 7 or 3, which is tK-19X/O-VK. Q^ Or the ultraviolet transmitting glass described in item 3. (6) Wavelength λ-2! The ultraviolet transmitting glass according to claims 1 to S, wherein the ultraviolet transmittance at 37 nm is 170% or more at a sample thickness of 3.1 mm.