CN111718120A

CN111718120A - Li-Al-Si photosensitive glass and preparation method thereof

Info

Publication number: CN111718120A
Application number: CN202010654262.5A
Authority: CN
Inventors: 方针; 陈宏伟; 高莉彬; 张继华; 陈雨哲; 曲胜; 邹思月; 王文君; 蔡星周; 穆俊宏
Original assignee: Chengdu Maike Technology Co ltd; University of Electronic Science and Technology of China
Current assignee: Chengdu Maike Technology Co ltd; University of Electronic Science and Technology of China
Priority date: 2020-07-09
Filing date: 2020-07-09
Publication date: 2020-09-29

Abstract

The invention provides a preparation method of Li-Al-Si photosensitive glass, which is prepared from the following raw materials in parts by weight: SiO 2₂75-80 parts of a solvent; li₂8-12 parts of O; al (Al)₂O₃2-5 parts; na (Na)₂1-4 parts of O; k₂3-6 parts of O; 1-2 parts of ZnO; sb₂O₃0.05-0.2 part; 0-2 parts of alkaline earth metal; CeO (CeO)₂0.02-0.15 part; ag₂0.05-0.15 part of O. The dielectric property and the mechanical property of the photosensitive glass are effectively improved by improving the proportion of the raw materials and simultaneously improving the production process, and compared with the Foturan photosensitive glass of the Schottky company, the dielectric property and the mechanical property are improved, so that the photosensitive glass can be applied in a high-frequency environment. In addition, due toThe improvement of mechanical performance can adapt to the development trend of miniaturization of the integrated circuit packaging volume. Meanwhile, the situation that the domestic adapter plate material depends on foreign manufacturers is improved, the domestic three-dimensional integrated packaging cost is reduced, and the development of domestic integrated circuits is promoted better.

Description

Li-Al-Si photosensitive glass and preparation method thereof

Technical Field

The invention relates to the field of three-dimensional integrated packaging adapter plates, in particular to Li-Al-Si photosensitive glass and a preparation method thereof.

Background

With the development of microelectronic technology, tunnel penetration equivalent quantum effect of integrated circuits is highlighted day by day, moore's law also meets unprecedented bottlenecks, and the bottlenecks are expected to be broken through by advanced three-dimensional integrated packaging technology. The interposer plays an important role in the three-dimensional integrated packaging technology: the chips are vertically interconnected through the high-density copper-plated through hole adapter plate, and the length of an interconnection line is greatly shortened, so that parasitic parameters, power consumption, signal delay, size and the like of a system are remarkably reduced. Among many interposer materials, Li-Al-Si photosensitive glass is considered to be the most potential three-dimensional interposer material due to its unique lithographic properties, low loss, high density of vias, low cost, strong insulation, and the like.

Currently, two types of commercial photosensitive glass are widely applied in the industry: (1) foturan (Germany Schottky) based on the Li-Al-Si glass system. (2) Photothermal glass (PTR) based on the Na-Zn-Al-Si glass system. The schottky photosensitive glass of schottky corporation is widely applied to many fields such as electronics, biology and the like due to its high precision of microstructure imaging and stable and reliable quality, and its electrical and mechanical properties are as follows:

with the coming of the 5G era, the working frequency of the chip can be increased to a GHz frequency band or even millimeter waves, which puts higher requirements on the dielectric property of the butt plate; the market demand for multi-functionality and miniaturization of electronic products forces further reduction in chip package size, which requires interposer smaller and thinner, which presents challenges to the mechanical performance of the interposer. The current Li-Al-Si photosensitive glass of Schottky company contains a large amount of alkali metal ions, so that the dielectric loss at high frequency is still not very optimistic, thereby limiting the application of the Li-Al-Si photosensitive glass in the high-frequency environment. On the other hand, with the development of miniaturization of the integrated circuit package volume, the thickness of the adapter plate is also continuously reduced, which also puts higher demands on the mechanical properties of glass. The most important point is that the domestic adapter plate material cannot always depend on photosensitive glass of Germany Schottky company, otherwise, the domestic three-dimensional integrated packaging cost is increased, and people can fall into a passive situation in the technical field of three-dimensional integrated packaging without mastering key technologies. Therefore, the photosensitive glass with high performance and low cost must be developed independently, and the subsequent processes of patterning, metallization, anodic bonding and the like are well mastered, which lays a solid foundation for the three-dimensional integrated packaging in China.

Therefore, the applicant filed application No. 201710144943.5 entitled "low dielectric loss sensitized photosensitive glass and production method" on 1/13/2017, and obtained photosensitive glass with low dielectric loss by improving the formula and preparation process of photosensitive glass, and further improved the formula and preparation process of photosensitive glass with better performance with the further research.

Disclosure of Invention

The invention aims to provide the Li-Al-Si photosensitive glass and the preparation method thereof, and further improve the dielectric property and the mechanical property of the photosensitive glass.

The technical scheme adopted by the invention for solving the technical problems is as follows: the preparation method of the Li-Al-Si photosensitive glass adopts the following raw materials by weight:

further, the alkaline earth metal includes one or more of MgO, CaO, BaO, and SrO.

Further, the alkaline earth metal includes MgO and CaO.

Further, the alkaline earth metal includes 0.5 parts of CaO and 0.5 parts of MgO.

Further, the method comprises the following steps:

uniformly mixing the raw materials and heating the raw materials to raise the temperature of the raw materials to 800-900 ℃ within 150-180 min, so as to produce gas and opaque sinter;

continuously heating the raw materials to enable the temperature of the raw materials to rise to 1200-1250 ℃ within 70-100 min, and enabling sinter to start to melt and be gradually transparent;

continuously heating the raw materials, heating the raw materials to 1400-1500 ℃ within 30-70 min, reducing the viscosity of the molten glass, and releasing gaseous impurities to clarify the molten glass;

the glass liquid is kept warm for 100-200 min at the temperature of 1400-1500 ℃ so that all components are uniformly distributed;

cooling the glass liquid within 30-70 min to 150-250 ℃, and then quenching the glass liquid to 200-300 ℃ within 20-50 min to obtain glass;

and (6) annealing.

Further, the annealing process comprises the following steps:

the initial temperature of the annealing furnace is 470-500 ℃, then the temperature is reduced to 180-220 ℃ at the speed of 0.11-0.143 ℃/min, and finally the annealing furnace is cooled to the room temperature within 500-800 min.

The Li-Al-Si photosensitive glass is prepared by the preparation method of the Li-Al-Si photosensitive glass.

Further, Si in the glass⁴⁺、Al³⁺And O^2-The molar amount of (A) satisfies: 1:2<(Si+Al):O<1:2.5。

The invention has the beneficial effects that: the dielectric property and the mechanical property of the photosensitive glass are effectively improved by improving the proportion of the raw materials and simultaneously improving the production process, and compared with Foturan photosensitive glass of Schottky company and photosensitive glass previously researched by the applicant, the dielectric property and the mechanical property are improved.

Drawings

FIG. 1 is a diagram showing the structure of a silica glass network.

FIG. 2 is a diagram of a structure of a Li-Al-Si photosensitive glass network.

FIG. 3 is a graph of glass samples made at different cooling rates.

FIG. 4 is a graph of the crystal nucleus growth rate and the crystal growth rate with respect to temperature.

FIG. 5 is a TG-DSC graph of a glass sample.

Fig. 6 is a schematic view of an ultraviolet absorption spectrum.

FIG. 7 is a picture of sample glass exposed and unexposed.

Figure 8 is the XRD diffractogram of the unexposed sample.

Figure 9 is the XRD diffractogram of the sample after exposure.

Fig. 10 is a schematic diagram of the raman spectrum of each sample.

FIG. 11 shows a Raman spectrum of 850-1250 cm^-1Is plotted with a gaussian fit.

FIG. 12 is a schematic diagram showing the area ratio of peaks fitted to a Gaussian-fit curve.

Fig. 13 is a graph of dielectric constant versus frequency for Sr-doped series samples.

FIG. 14 shows dielectric loss values of Sr-doped series samples at frequencies around 1 GHz.

Fig. 15 is a curve of flexural strength and surface hardness of Sr-doped series samples.

FIG. 16 is a graph of glass melting.

Fig. 17 is an annealing profile.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

The preparation method of the Li-Al-Si photosensitive glass adopts the following raw materials in parts by weight:

most of the quartz glass network structures are connected by Si-O-Si bridge oxygen bonds with strong bonds, so that the quartz glass network structures have the advantages of excellent dielectric property and stability, small thermal expansion coefficient and the like, and are considered to be ideal glass structures, and the structural schematic diagram is shown in FIG. 1. However, quartz glass is not photosensitive and has a high melting point (1713 ℃), which greatly increases the energy consumption, and if the quartz glass is used as the material of the adapter plate, laser through holes are required, which greatly increases the cost of the adapter plate.

This drawback is exactly compensated by the Li-Al-Si photosensitive glass, which is still predominantly SiO for good performance₂The content is mainly, and the mass fraction accounts for more than 75 percent of the total content. However, after adding an oxide containing Li, Na, K alkali metals, Li⁺The glass network is mainly 'accumulated' due to the larger field intensity of the positive ions, while Na⁺，K⁺It mainly acts as a "break" and the bridging oxygen bond is broken to form a non-bridging oxygen bond, as shown in FIG. 2 (R in the figure represents an alkaline earth metal), so that a silicon-oxygen tetrahedron [ SiO ] is formed₄]The original integrity and symmetry are destroyed, thus causing the glass structure to be loose and the performance to be poor. Further, the larger the alkali metal content is, the more the performance is deteriorated, so that it is necessary to control the alkali metal content. The alkali metal is added for two reasons: (1) alkali metal has the function of high-temperature melting assistance, so that SiO₂Can be melted at 1400-1500 ℃ so as to reduce the energy consumption and the equipment performance requirement. (2) Li⁺Is separation outLithium metasilicate of (II)₂SiO₃Important component of crystal phase, adding Na⁺And K⁺The formation of the "mixed alkali effect" reduces the diffusion coefficient of the alkali metal and thus the dielectric loss, thermal expansion coefficient, etc. of the glass. Aluminum oxide Al₂O₃As an intermediate oxide, trapping free oxygen in the periphery, in tetrahedra [ A1O ]₄]^5-Enter into the glass network, which can improve the viscosity, stability, mechanical strength and the like of the glass melt, but excessive aluminum oxide Al₂O₃Can affect the electrical property of the glass, and most of the glass introduces Al₂O₃The content of (A) is 1% -3.5%. [ A1O₄]^5-Ratio [ SiO ]₄]^4-One more negative charge neutralizes the extra-network ionic phase, such as alkali or alkaline earth metals, to reduce charge stress. The addition of alkaline earth metals is on the one hand to further prevent Li⁺、Na⁺、K⁺The alkali metal ions migrate along with an external electric field, on the other hand, the alkali metal ions are used for filling gaps of the glass network to enhance compactness, so that the mechanical property is improved, in addition, the alkaline earth metal ions belong to inert gas ions, so that the polarizability is low, the coordination number in the glass network is large, and the alkali metal ions are a good glass network modifier, and therefore, the mechanical property and the dielectric property of the glass can be improved by doping a proper amount of alkaline earth metal. Proper zinc oxide can improve the alkali resistance of the glass and can also protect Ag + from being reduced by silver atoms Ag at high temperature, and excessive zinc oxide can enhance the glass crystallization tendency. Sb₂O₃Is not only a reducing agent, but also a related reduction reaction formula

2Ce⁴⁺+Sb³⁺→2Ce³⁺+Sb⁵⁺

While Sb₂O₃And is a clarifying agent. Ce₃₊The absorption of photon energy to release the free electrons required for crystallization plays the role of a photosensitizer. The nucleating agent Ag + captures the free electrons to form clusters, and gradually grows into crystal nuclei with the rise of temperature to induce the lithium metasilicate crystal phase (Li)₂SiO₃) And (4) precipitating.

Among alkaline earth metals, radium, beryllium and the like are radioactive or extremely toxic, and therefore, the alkaline earth metal of the present invention includes one or more of MgO, CaO, BaO and SrO.

The reasonable glass sintering temperature curve and annealing temperature curve are the premise of preparing the Li-Al-Si photosensitive glass with stable structure and performance, and multiple tests show that when the highest sintering temperature is lower (<1450 ℃), the insufficient sintering of powder can cause obvious small bubbles, as shown in No. 1 in FIG. 3; the sintering temperature is increased, and the unknown yellow filaments sometimes appear as 2# in figure 3 when the heat preservation time is longer; as a result of continued research, a clear glass was finally obtained without visible bubbles and any unidentified yellow filaments as shown in # 3 of fig. 3, and the improved glass forming process comprised the following five stages:

stage one: uniformly mixing the raw materials and heating the raw materials to raise the temperature of the raw materials to 800-900 ℃ within 150-180 min, so as to produce gas and opaque sinter. Before 800-900 ℃, the raw materials mainly take part in the reaction in a solid state, and the product contains CO₂Isogas and silicate and SiO₂An opaque agglomerate of the composition.

And a second stage: and continuously heating the raw materials to enable the temperature of the raw materials to rise to 1200-1250 ℃ within 70-100 min, and enabling sinter to start to melt and be gradually transparent. As the temperature rises to 1200-1250 ℃, the sinter begins to melt slowly until the sinter is transparent, but a large amount of bubbles, stripes and uneven components exist in the molten glass.

And a third stage: and continuously heating the raw materials, heating the raw materials to 1400-1500 ℃ within 30-70 min, reducing the viscosity of the molten glass to about 10 Pa.s, and releasing gaseous impurities to clarify the molten glass.

And a fourth stage: the glass liquid is kept at 1400-1500 ℃ for 100-200 min, and due to the diffusion effect, all chemical components tend to be uniformly distributed gradually, and at the moment, stripes and bubbles are reduced gradually.

And a fifth stage: and cooling the glass liquid to 150-250 ℃ within 30-70 min so as to enable the glass liquid to have proper viscosity during discharging, and then quenching the glass liquid to 200-300 ℃ within 20-50 min to obtain the glass. Since glassy materials have a greater internal energy than crystalline materials, the principle of energy minimization is usedGlass always has a tendency to reduce the conversion of self-generated internal energy into polycrystals. The reason why the glass is stable is that the difference from the energy in the crystal cannot be larger than the devitrification barrier, otherwise the glass will crystallize. The core view of the dynamics is that: the cooling rate of the glass melt is critical to glass formation. The support for this view is based on the fact that the best glass products (e.g., SiO)₂、B₂O₃Etc.) crystals also precipitate after the melt is slowly cooled; even a metal which is not suitable for vitrification can be a metallic glass by cooling the molten metal at a rate higher than the rate at which the particles are arranged into crystals. In the process of quenching from a melt to a glass body, nucleation and crystal growth are two processes of material crystallization, fig. 4 is a graph of the rate of nucleation and crystal growth versus temperature, the rate of crystal growth increases and then decreases to 0 in the process of temperature decrease from d to b, the rate of nucleation increases and then decreases to 0 in the process of temperature decrease from c to a, the crystallization condition is that crystals grow on the basis of the nuclei, i.e. crystallization occurs in the temperature interval between b and c, and then to prevent or reduce crystallization, the time of glass decrease from temperature c to temperature b, i.e. increase the cooling rate, can be reduced. Therefore, the invention quenches the glass liquid to 200-300 ℃ within 20-50 min, reduces the crystallization phenomenon and ensures the glass quality.

In the discharging and cooling process, stress is inevitably generated in the glass matrix due to the influence of conditions such as cooling environment, pouring method and the like. The presence of such stresses will greatly reduce the mechanical strength of the glass and may even lead to glass cracking. To relieve this stress and improve the homogeneity of the chemical composition of the glass, it is necessary to subject the glass to a temperature environment for a sufficient time and then to cool it down slowly so that the stress is no longer present beyond the permissible range. We will refer to this process as annealing heat treatment of the glass. The glass samples prepared by different smelting temperature curves have different performances, and particularly, the heat treatment annealing curve after the glass body is cast and molded directly influences the mechanical performance of the glass body, so a more reasonable annealing process parameter curve needs to be explored, and the annealing process specifically comprises the following steps:

The upper annealing temperature of the glass may be set at the transition temperature T_gAbove and softening temperature T_sThe following. On the one hand, in the temperature range, the diffusion barrier in the glass matrix is lowered, and the mass points can absorb heat to displace, so that the thermal stress generated by the temperature gradient in the glass body and the structural stress generated by the nonuniformity of the components are weakened. On the other hand, softening temperature T_sGenerally below the crystallization temperature T_cSo that spontaneous crystallization in the glass body can not occur, and the shape of the glass formed by pouring can not be changed.

FIG. 5 is a TG-DSC plot of a glass sample, the transition temperature T of which can be derived from FIG. 5_gA melting point temperature T of about 470 DEG C_mAt 932 ℃, an exothermic peak with a downward peak does not exist in the whole temperature rising process, which shows that an unexposed sample cannot spontaneously crystallize only due to heating, and the crystallization performance is stable. And meanwhile, the TG curve is observed, the weight of the glass is almost kept unchanged in the temperature rise process, which indicates that the glass sample does not contain the components which are easily volatilized or decomposed by heating, and further indicates that the glass has better thermal stability.

The annealing of the glass is essentially represented by the following two processes: first, stress is reduced and even eliminated; second, new stresses are prevented from being generated. In the cooling process after the heat preservation is finished, the generation of the stress in the glass body is mainly related to the temperature gradient, and the stress generated by different cooling rates, the thickness of the product and the properties of the product is different. Based on the above analysis and the DSC test results of the samples, the maximum annealing temperature was set at 500 ℃, and the cooling rate was determined according to the thickness and shape of the test sample.

In order to reduce Li⁺，Na⁺And K⁺Under the action of external electric field, the mobility and densified glass network structure need to be doped with some metal oxides with low self-polarizability, strong cation field and moderate radius. Based on the characteristics, the invention adopts alkaline earth metal series with a large coordination numberAnd (5) doping the rows. With alkali metal ions (Li)⁺Except for the fact that the field intensity of alkaline earth metal ions is larger, the binding capacity with oxygen ions is stronger, and the radius is slightly larger than that of alkali metal ions, so that the mobility of the alkaline earth metal ions is slower under the action of an external electric field, and the migration of the alkali metal ions can be effectively blocked. However, the alkaline earth metal ions also belong to the extranet ions, and too much content also causes the non-bridge oxygen content to be increased sharply to destroy the stability of the glass network structure, so that the optimal doping content of each alkaline earth metal ion needs to be explored to obtain more excellent performance, and then under the condition that other raw materials and production processes are not changed, the types and the content of the alkaline earth metals are changed to prepare a plurality of glass samples so as to verify the influence of the types and the content of the alkaline earth metals on the glass performance.

The experimental sample, undoped with alkaline earth metal (0 wt%), was designated S₀Using the content of doped SrO as index for naming, e.g. C_0.5，C₁，C_1.5，C₂Respectively represent 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt% of SrO doped samples.

(I) photosensitive Performance verification

The photosensitivity is the basic premise of the Li-Al-Si photosensitive glass in the experiment, and whether the photosensitivity is possessed or not determines whether the subsequent micro-patterning processes such as exposure, etching and the like are realized or not. To verify the photosensitive properties of the glass samples of the present experiment, the exposure wavelength was first determined according to the ultraviolet absorption spectrum test of the glass samples, as shown in fig. 6: a distinct absorption peak exists at a wavelength of about 310nm, and the peak corresponds to Ce₃₊The reaction process of absorbing photon energy and releasing electrons is shown in the formula in the figure. And then placing the polished sheet photosensitive glass sample under the ultraviolet light of a mercury lamp with the wavelength of about 310nm for mask exposure for 15min, and after exposure is finished, cleaning the surface of the glass sample, and then placing the glass sample into an annealing furnace for annealing and developing.

In order to form lithium metasilicate (Li) from the glass sample after exposure₂SiO₃) And (3) adopting an annealing process as follows: placing the exposed and unexposed glass samples into a high-temperature annealing furnace, heating to 555 ℃ along with the furnace at the speed of 3 ℃/min, and then preserving heat for two timesAnd slowly cooling to room temperature at the cooling rate of 1 ℃/min. As is evident from fig. 7, the uv exposed and annealed samples turned into reddish brown glass-ceramics, while the samples that were not uv exposed but were subjected to the same annealing procedure still appeared to be transparent colored glassy. To determine the phase of the reddish-brown crystals, and the presence or absence of microcrystalline phases in the unexposed vitreous, two samples were subjected to X-ray diffraction analysis (XRD) tests, which showed: as shown in fig. 8, the unexposed sample does not have any sharp crystallization peak on the test curve, indicating that the sample is still in a glassy state, i.e., does not form any crystalline phase. However, as shown in FIG. 9, the XRD profile of the exposed glass sample showed distinct crystallization peaks, and it was confirmed from the comparison of standard cards PDF #72-1140 and PDF #40-0376 that most of the crystals formed in the exposed glass were lithium metasilicate Li₂SiO₃Only a very small proportion of the crystals is the lithium disilicate crystal phase Li₂Si₃O₅。

The above results indicate that the alkaline earth metal Sr²⁺Does not affect the photosensitivity of the Li-Al-Si photosensitive glass and may even promote selective devitrification properties, such as C_1.5Peak intensity around 38 ° is greater than S₀Peak intensity of the sample.

(II) analysis of structural Properties

Under the condition of unchanging external conditions, the microscopic network structure of the glass sample must be consolidated to improve the performance of the glass sample. To explore alkaline earth metal Sr₂₊The structural influence on the structure of the glass grid after entering the glass grid can be analyzed through a Raman spectrum chart of the series of samples, the Raman spectrum is shown as the following figure 10, and the vibration modes corresponding to the Raman spectrum are as follows:

from the Raman spectra and the vibration mode table, except C_0.5In addition to the samples, 3 other doped samples and undoped samples S₀The raman peak shift and intensity change is very small, at least indicating that the small amount of SrO doping does not cause significant damage to the glass network structure. But C is_0.5The sample is at 471cm^-1The peak ratio of bending vibration of the oxygen-bridged Si-O0 sample S₀Higher, and at 555cm^-1And 1080cm^-1The peak of vibration is significantly lower and this microstructure may cause a change in the properties of the sample.

From the above analysis, it can be seen that SrO doping within 2 wt% has little effect on the vibration of the glass network, does not cause more vibration loss, and the dielectric and mechanical properties of the glass are improved mainly with Sr²⁺Influence QⁿThe content distribution of (n is 1, 2, 3, 4, n is the number of bridging oxygens). To further understand Sr²⁺How to influence the microstructure of the glass needs to be 850-1250 cm in Raman spectrum^-1Is gaussian fitted. In the above frequency band, approximately 950cm^-1,1000cm^-1,1090cm^-1,1150cm^-1Respectively correspond to Q¹(Si₂O₇ ^6-dimmer),Q²(SiO₃ ^2-chain),Q³(Si₂O₅ ^2-sheet),Q⁴(SiO₂3Dnetwork) structural unit, and the fitted curve is shown in fig. 11.

The ratio of the fitted 4 peak areas corresponds to the corresponding Q¹,Q²,Q³,Q⁴The relative content of structural units in the glass structure, calculated by fitting, gives the ratio of the areas of the 4 fitted peaks in percent, as shown in figure 12. Can be seen visually on the three-dimensional sector map, from S₀To C₁Sample, Q⁴The relative content of structural units is reduced from 36.16% to 18.34%, whereas Q is³The structural unit is increased from 31.59% to 54.94%, Q₁The relative content of structural units being substantially constant, Q²The content of structural units tends to decrease. When the doping content of SrO exceeds 1%, the trend starts to reverse: q²、Q⁴Structural unitThe relative content of (A) is slightly increased, Q³The content of structural units is reduced. These two distinct phenomena can be explained by the following two equations:

is like

2Q⁴+Q^2-→2Q³

Formula II

In the formula O^2-The source and free oxygen provided by SrO. When the doping content of SrO is less than 1 wt%, the equations together play a major role: q⁴The structural unit absorbs free oxygen from SrO to Q³A structural unit. Q²Structural units are also converted to Q in a small portion by the reaction of formula II³(ii) a Q once the doping content of SrO exceeds 1 wt%³Too high a content of structural units will partially convert to Q⁴Structural unit and Q²A structural unit. If the doping content of the alkaline earth metal is too high, the following reaction processes mainly occur in addition to the reaction process of formula one

Formula III

2Q³+Q^2-→2Q²

Formula IV

2Q²+Q^2-→2Q¹

Q²And Q¹The increase of structural units will seriously destroy the silicon-oxygen tetrahedron [ SiO ]₄]And stability, which is why excessive alkaline earth doping will lead to deterioration of the glass properties.

After understanding the effect of the alkaline earth metal oxide SrO on the glass structure, we can look at the results of the performance tests of the series of samples as shown in fig. 13, 14 and 15, where the five-pointed star represents the sample with the best overall performance in the series (same below). Comparing the experimental results of dielectric and mechanical properties here with the previous structural analysis, the following can be found: except that C_0.5Values of dielectric loss and dielectric constant outside the sampleWith Q³Increase in structural units decreases with Q³Decrease and increase of structural units; the values of flexural strength and surface hardness are exactly opposite to the dielectric properties: mechanical properties first following Q³Increase with increasing structural units, and then with Q³The reduction of the structural units becomes weaker. Wherein C is₁Q of (2)³The content of the structural unit is highest, so the comprehensive performance is strongest. C as predicted by Raman spectroscopy_0.5The dielectric constant, dielectric loss and bending strength of the sample deviate from the change trend of the system. After analysis and investigation, C_0.5The reason for the abnormal sample is probably caused by the large non-uniformity of the components in the matrix of the sample, because the result of the test of preparing the sample by the same sintering and annealing processes after the sample is prepared again and ground uniformly is greatly improved, for example, the mechanical strength is changed from 78.5MPa to 155MPa, so that the mechanical property of the sample in the group C is changed from S₀To C₁To C₂Substantially corresponding to the trend of increasing first and then decreasing (as explained herein, not shown).

(III) analysis of the cause of the results

The reasons for the improvement of the dielectric property and the mechanical property of the experimental glass sample are mainly related to the following two aspects: on the one hand, in the case of the introduction of network exosome ions in the glass structure, Q³The structural units being able to make silicon-oxygen tetrahedrons [ SiO ]₄]The damage degree is the lowest, thereby ensuring the stability of the glass network structure. When an appropriate amount of Sr²⁺Interstitial sites of the tetrahedral network that, after entering the glass network, act as network modifiers (acting as an accumulator for the glass network) located in the vicinity of the negatively charged nonbridging oxygens (NBO), due to their larger ionic radius than Li⁺、Na⁺、K⁺And the electric field intensity (Z/r) of the positive ions₂) Also has larger bonding force with non-bridge oxygen bond than Na⁺、K⁺Binding force with non-bridged oxygen bond, Sr under the action of external electric field²⁺Can effectively block Li⁺、Na⁺、K⁺Thereby reducing dielectric losses. On the other hand, Q³The increase of the structural units can increase the external body positive of the network positioned around the negatively charged NBOThe distribution of ions is uniform, thereby reducing structural stress caused by non-uniform composition. At the same time Sr₂₊Also acts as a charge balancing agent in the glass micro-network structure_[58]The tetrahedron [ A1O ] under the action of coulomb force₄]^5-And the phase neutralization is adopted, so that the charge stress is reduced, and simultaneously the compactness of the glass is improved, so that the mechanical strength of a photosensitive glass sample is improved.

As can be seen from the test results of the SrO doping series samples, the dielectric properties are minimized and the mechanical properties are maximized within the doping range of 0 wt% to 2 wt%, and as the SrO doping content exceeds 1 wt%, the dielectric properties and the mechanical properties are generally deteriorated, indicating that the doping range should be controlled to not exceed 1 wt%.

Because Mg, Ca, Sr and Ba belong to the same group of elements and are all external ions of the glass network, the modification principle of the glass network is basically the same, but the properties (cation field strength, ion radius and the like) are slightly different, and the modification strength of the glass network is also different. Thus, respectively in the original glass sample S₀Mg, Ca and Ba are doped in the glass, the influence of each alkaline earth metal on the glass performance is verified according to the mode, and then two alkaline earth metals which are MgO and CaO and have the best improvement on the glass performance are selected. Respectively on the original glass sample S₀The method is characterized in that MgO and CaO with different contents are doped in the alkaline earth metal to finally obtain the optimal type and proportion of the alkaline earth metal: as the alkaline earth metal, 0.5 part of CaO and 0.5 part of MgO were used.

The Li-Al-Si photosensitive glass is prepared by the preparation method of the Li-Al-Si photosensitive glass, and Si in the glass⁴⁺、Al³⁺And O^2-The molar amount of (A) satisfies: 1:2<(Si+Al):O<1:2.5

The quality of the microscopic glass network structure determines the quality of the macroscopic performance, and the glass network structure is mainly in direct relation with the content of each chemical component, so that the proper chemical component distribution ratio is the basis for obtaining a stable and firm glass network. The optimization idea of the chemical component proportion of the Li-Al-Si photosensitive glass is derived from a quartz glass network structure, because the latter has excellent dielectric property and dielectric propertyAn electrical constant of 3.7 to 3.9 and a dielectric loss of 10^-4An order of magnitude. In the quartz glass network structure (see FIG. 1), basically, Si-O-Si bridge oxygen bonds with large bond energy and no network exo-ions with high mobility are present, each [ SiO ] is₄]Si in tetrahedron, O is 1:2 (molar ratio); in the Li-Al-Si photosensitive glass network structure, the introduction of alkali metal and other oxides will inevitably cause the breakage of partial bridging oxygen bonds to form Si-O non-bridging oxygen bonds with lower bond energy and Li exists in network gaps⁺，Na⁺，K⁺And free O^2-And iso-network external body ions. If the number of non-bridging oxygen bonds is larger, the framework of the glass network is loosened, so that a series of performances are deteriorated. To let [ SiO ]₄]The damage degree of the integrity and symmetry of tetrahedron is reduced to the minimum, and the damage is ideally suffered from [ SiO ]₄]At most one non-bridging oxygen bond occurs in the tetrahedron (see fig. 2), then Si: O ═ 1:2.5 (molar ratio) in the tetrahedron. Therefore, in designing the chemical composition distribution ratio of the glass, in order to minimize the destruction of non-bridging oxygen, it is necessary to control the amount of oxygen ions in the glass network, so that the glass network forming body Si is used⁴⁺With intermediate Al³⁺The sum of the molar amounts of (A) and (B) being equal to O provided by all oxides^2-The molar amount of (b) satisfies the following inequality:

1:2<(Si+Al):O<1:2.5

the formula is realized by the proportion of each component.

Example one

The material is prepared from the following raw materials in parts by weight:

the preparation process comprises the following steps:

the melting curve shown in fig. 16 was used: uniformly mixing the raw materials and heating the raw materials to raise the temperature of the raw materials to 800-900 ℃ within 150-180 min, so as to produce gas and opaque sinter;

and cooling the glass liquid to 150-250 ℃ within 30-70 min, and then quenching the glass liquid to 200-300 ℃ within 20-50 min to obtain the glass.

Annealing, using the annealing profile shown in fig. 17: the initial temperature of the annealing furnace is 470-500 ℃, then the temperature is reduced to 180-220 ℃ at the speed of 0.11-0.143 ℃/min, and finally the annealing furnace is cooled to the room temperature within 500-800 min.

Sampling the prepared Li-Al-Si photosensitive glass, respectively coating round electrodes with the diameter of 6mm on two sides of the sample and the uniform thickness, putting the sample into an oven for drying, and then putting the sample into a high-temperature dielectric tester, wherein the test procedure is as follows: the test voltage is 1V, the test frequency is 1GHz, the temperature range is 25-300 ℃, the heating rate is 4 ℃/min, and the temperature deviation is +/-0.30 ℃. Thus, the dielectric constant and dielectric loss at a specific frequency were measured as a function of temperature.

The bending strength of a strip-shaped glass sample of 4mm multiplied by 50mm is tested by adopting a SANSCMT-6104 bending resistance tester and a three-point bending loading method, and the Vickers hardness and the expansion coefficient of the sample are measured.

The results of the tests are compared to the existing schottky barrier photosensitive glass as shown in the table below:

therefore, the mechanical property of the Li-Al-Si photosensitive glass prepared by the invention is superior to that of the Foturan photosensitive glass of the Schottky company, the dielectric loss is far lower than that of the Foturan photosensitive glass of the Schottky company, the overall performance is greatly improved, and the Li-Al-Si photosensitive glass can be applied in a high-frequency environment. In addition, due to the improvement of mechanical performance, the method can adapt to the development trend of miniaturization of the integrated circuit package volume. Meanwhile, the situation that the domestic adapter plate material depends on foreign manufacturers is improved, the domestic three-dimensional integrated packaging cost is reduced, and the development of domestic integrated circuits is promoted better.

Claims

The preparation method of the Li-Al-Si photosensitive glass is characterized by comprising the following steps of:
2. the method for producing a Li-Al-Si photosensitive glass according to claim 1, wherein the alkaline earth metal includes one or more of MgO, CaO, BaO, and SrO.
3. The method of producing a Li-Al-Si photosensitive glass according to claim 2, wherein the alkaline earth metal includes MgO and CaO.
4. The method of producing a Li-Al-Si photosensitive glass according to claim 3, wherein the alkaline earth metal includes 0.5 parts of CaO and 0.5 parts of MgO.
5. The method for producing a Li-Al-Si photosensitive glass according to claim 1, comprising the steps of:

uniformly mixing the raw materials and heating the raw materials to raise the temperature of the raw materials to 800-900 ℃ within 150-180 min, so as to produce gas and opaque sinter;

continuously heating the raw materials to enable the temperature of the raw materials to rise to 1200-1250 ℃ within 70-100 min, and enabling sinter to start to melt and be gradually transparent;

continuously heating the raw materials, heating the raw materials to 1400-1500 ℃ within 30-70 min, reducing the viscosity of the molten glass, and releasing gaseous impurities to clarify the molten glass;

the glass liquid is kept warm for 100-200 min at the temperature of 1400-1500 ℃ so that all components are uniformly distributed;

cooling the glass liquid within 30-70 min to 150-250 ℃, and then quenching the glass liquid to 200-300 ℃ within 20-50 min to obtain glass;

and (6) annealing.
6. The method of producing a Li-Al-Si photosensitive glass according to claim 5, wherein the annealing process is:

the initial temperature of the annealing furnace is 470-500 ℃, then the temperature is reduced to 180-220 ℃ at the speed of 0.11-0.143 ℃/min, and finally the annealing furnace is cooled to the room temperature within 500-800 min.
The Li-Al-Si photosensitive glass characterized by being produced by the method for producing a Li-Al-Si photosensitive glass according to any one of claims 1 to 6.
8. The Li-Al-Si photosensitive glass according to claim 7, wherein Si in the glass⁴⁺、Al³⁺And O^2-The molar amount of (A) satisfies: 1:2<(Si+Al):O<1:2.5。