Low-temperature melting borate sealing glass powder and method for preparing the same, and solder

Abstract

The embodiment of the application discloses a low-temperature melting type borate sealing glass powder and a preparation method and solder thereof, the glass powder comprises the following components in percentage by mass: alkali metal oxide: 0-10%; transition metal oxide: 3-60%; B2O3: 10-45%; Al2O3: 0-9%; SiO2: 0-29%; other metal oxide: 0-20%. The application can be melted at 900-1100 DEG C, can use cheap corundum crucible to replace precious metal platinum crucible to fill powder and melt borate glass; can use cheap electric heating wire heating frit furnace to replace relatively expensive silicon-carbon rod or silicon-molybdenum rod heating frit furnace to melt borate glass; reduces the volatilization of boron trioxide in the melting process, and improves the stability of the melting borate glass.

Description

Technical Field

[0001] This invention relates to the field of electronic component sealing technology, and in particular to a low-temperature melting borate sealing glass powder, its preparation method, and solder. Background Technology

[0002] Borate glass is currently the commonly used sealing glass for medium-temperature brazing, often used for hermetic sealing of electronic components. Borate glass is typically melted at 1200-1600℃. Because borates cause significant corrosion to most low-cost ceramic crucibles above 1200℃, precious metal platinum crucibles are often used. Furthermore, above 1200℃, borates decompose and release boron trioxide gas, making the composition uncontrollable and affecting the stability of batch sealing quality.

[0003] Some methods use water-soluble raw materials such as organosilicon salts and aluminum nitrate to calcine and melt borate glass powder at low temperatures. However, a large amount of dangerous nitrate-containing gas is generated during the baking process, which significantly increases the cost of glass powder melting. For example, the invention patent with application number CN201910210811, entitled "A low-melting-point borate material with wave-transmitting properties and its preparation method," discloses a borate material.

[0004] Some glass powders are made by calcining water-soluble raw materials such as organometallic salts and organosilicon salts. However, because organometallic salts are not fully decomposed before the glass melts, they generate a large amount of gas during the melting process, which prevents the glass from melting effectively. Therefore, they can only be used by calcining at temperatures below the glass melting point. This limits the scope of application of this type of glass powder. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of the present invention is to provide a low-temperature melting borate sealing glass powder and its preparation method and solder, so as to achieve low-temperature melting and reduce costs.

[0006] To address the aforementioned technical problems, this invention provides a low-temperature melting borate sealing glass powder, comprising the following components by mass percentage: alkali metal oxides: 0-10%; transition metal oxides: 3-60%; B2O3: 10-45%; Al2O3: 0-9%; SiO2: 0-29%; other metal oxides: 0-20%.

[0007] Furthermore, it comprises the following components by mass percentage: B2O3: 39.7%; ZnO: 47.9%; CuO: 9%; SiO2: 3.4%.

[0008] Further, by mass percentage, it comprises the following components: K2O and / or Na2O: 2.7%; B2O3: 29.3%; ZnO: 36.8%; Al2O3: 3.3%; SiO2: 21.5%; BaO: 6.4%.

[0009] Accordingly, embodiments of the present invention also provide a method for preparing low-temperature melting borate sealing glass powder, comprising the following steps: 1) Mix the raw materials; 2) Dry and calcine the raw materials; 3) Crush and ball-mill the calcined raw materials to obtain powder; 4) Melt the powder at high temperature to make glass; 5) Quickly cool and crush the glass; 6) Dry and ball-mill the crushed glass sand into powder.

[0010] Furthermore, the raw materials in step 1) include, by mass percentage: Potassium feldspar powder: 0-50%; spodumene powder: 0-30%; lithium carbonate: 0-10%; boric acid: 0-20%; zinc borate: 10-80%; lithium borate: 0-10%; zinc oxide: 0-20%; calcium carbonate: 0-20%; quartz powder: 0-20%; kaolin: 0-20%; other metal oxides: 0-10%.

[0011] Furthermore, in step 2), the calcination temperature is 800℃.

[0012] Furthermore, in step 4), the melting temperature is 900-1100℃.

[0013] Accordingly, this invention also provides a solder, which is obtained by dry pressing the aforementioned low-temperature melting borate sealing glass powder and then sintering and hardening it at high temperature.

[0014] The beneficial effects of this invention are as follows: the invention can be obtained by melting at 900-1100℃; a cheap corundum crucible can be used instead of a precious metal platinum crucible to fill the powder and melt borate glass; a cheap electric heating wire melting furnace can be used instead of a relatively expensive silicon carbide rod or silicon molybdenum rod melting furnace to melt borate glass; the volatilization of boron trioxide during the melting process is reduced, and the stability of the composition of the melted borate glass is improved. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the light window according to an embodiment of the present invention.

[0016] Explanation of icon numbers 10. Glass solder, 20. 4J29 Kovar shell, 30. Sapphire glass sheet. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] In this embodiment of the invention, directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0019] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0020] The low-temperature melting borate sealing glass powder of this invention comprises the following components by mass percentage: Alkali metal oxides: 0-10%; Transition metal oxides: 3-60%; B2O3: 10-45%; Al2O3: 0-9%; SiO2: 0-29%; Other metal oxides: 0-20%.

[0021] Alkali metal oxides are oxides formed from active metals such as sodium oxide (Na2O) and potassium oxide (K2O) (e.g., Na2O, K2O, CaO, MgO, and PbO); transition metal oxides are ZnO, CdO (cadmium oxide), etc.; other metal oxides are oxides of metal elements in the periodic table such as magnesium oxide and calcium oxide.

[0022] In one embodiment, the product comprises the following components by mass percentage: B2O3: 39.7%; ZnO: 47.9%; CuO: 9%; SiO2: 3.4%.

[0023] As one implementation, the product comprises the following components by mass percentage: K2O and / or Na2O (i.e., K2O+Na2O): 2.7%; B2O3: 29.3%; ZnO: 36.8%; Al2O3: 3.3%; SiO2: 21.5%; BaO: 6.4%.

[0024] The preparation method of low-temperature melting borate sealing glass powder according to an embodiment of the present invention includes the following steps: 1) mixing raw materials by molar ratio; 2) drying and calcining the raw materials (calcination temperature is 800℃); 3) crushing and ball milling the calcined raw materials to obtain powder; 4) melting the powder into glass at high temperature (melting temperature is 900-1100℃); 5) rapidly cooling and crushing the glass; 6) drying and ball milling the crushed glass sand into powder.

[0025] In one implementation, the raw materials in step 1) include, by mass percentage: Potassium feldspar powder: 0-50%; spodumene powder: 0-30%; lithium carbonate: 0-10%; boric acid: 0-20%; zinc borate: 10-80%; lithium borate: 0-10%; zinc oxide: 0-20%; calcium carbonate: 0-20%; quartz powder: 0-20%; kaolin: 0-20%; other metal oxides: 0-10%.

[0026] The solder in this embodiment of the invention is obtained by dry pressing low-temperature melting borate sealing glass powder and then sintering and hardening it at high temperature. The solder is aligned with the area to be sealed and is usually prepared in a ring shape for hermetic sealing of electronic components.

[0027] Example raw materials: potassium feldspar (K2O content greater than 12%); light zinc oxide (industrial or analytical grade); heavy zinc oxide (industrial or analytical grade); light zinc borate (industrial or analytical grade); heavy zinc borate (industrial or analytical grade); fused silica powder (industrial grade); copper oxide powder (industrial or analytical grade); other metal oxides (industrial grade).

[0028] Equipment and main tools: electronic balance, jar mill, corundum jar, zirconia balls, drying oven, corundum crucible cup, high temperature box furnace, hammer crusher, dry pressing machine, air atmosphere tube furnace, nitrogen atmosphere mesh belt furnace, digital display push-pull force tester. Process flow: 1. Raw material mixing; 2. Raw material drying and calcination (800℃); 3. Crushing and ball milling; 4. Powder filling cups and high-temperature melting into glass (900-1100℃); 5. Glass body removal and rapid cooling and crushing; 6. Glass sand drying and ball milling into powder; 7. Glass powder granulation by sieving; 8. Dry pressing into solder rings; 9. High-temperature sintering and hardening (aging) of solder rings; 10. Assembling Kovar shell, glass, and solder rings into a clear window and high-temperature welding in a mesh belt furnace; 11. Strength testing, etc.

[0029] Example 1

[0030] The chemical composition of borate glass powders LR660-1 and LR660-2 is the same. The chemical composition (mass percentage) is: B2O3: 39.7%; ZnO: 47.9%; CuO: 9%; SiO2: 3.4%.

[0031] The raw material composition of borate glass powder LR660-1 is as follows: Heavy zinc borate: 75%; Heavy zinc oxide powder: 14%; Copper oxide powder: 8%; Fused silica powder: 3%.

[0032] The raw material composition of borate glass powder LR660-2 is as follows: Light zinc borate: 75%; Light zinc oxide powder: 14%; Copper oxide powder: 8%; Fused silica powder: 3%.

[0033] Process flow: 1. Raw material mixing; 2. Raw material drying and calcination (800℃); 3. Crushing and ball milling; 4. Powdered material is placed in a corundum crucible and melted at high temperature to form glass; 5. Glass body is removed and rapidly cooled and crushed; 6. Glass sand is dried and ball-milled into powder; 7. Glass powder is granulated by sieving; 8. Dry pressing is formed into solder rings; 9. Solder rings are sintered and hardened at high temperature (aging); 10. Kovar shell, glass and solder rings are assembled into a clear window and brazed at high temperature in a mesh belt furnace; 11. Strength testing, etc.

[0034] In an LR660-1, boron trioxide and zinc oxide are made from heavy zinc borate and heavy zinc oxide. After being calcined and ball-milled into powder, the powder is placed in a corundum crucible cup and melted in a high-temperature box furnace at 1280°C for two hours to be melted into a liquid. Another type of LR660-2 uses light zinc borate and light zinc oxide. After being ball-milled into powder, the powder is placed in a corundum crucible and melted in a high-temperature box furnace at 950°C for two hours until it becomes liquid.

[0035] After LR660-1 and LR660-2 are melted, they are poured out, rapidly cooled, crushed, and ball-milled into powder.

[0036] After the crucibles cooled, the corundum crucible containing LR660-1 material was inspected, and corrosion grooves with a depth of more than 1 mm were found on the inner wall. The corundum crucible containing LR660-2 material was inspected, and no obvious corrosion grooves were found on the inner wall.

[0037] Solder rings made from LR660-1 and LR660-2 glass powders were dry-pressed and aged before being assembled with a 4J29 Kovar housing and a sapphire glass plate to form an optical window (as shown in the attached image). Figure 1 As shown, 20 is a 4J29 Kovar shell, 10 is glass solder, and 30 is a sapphire glass sheet (outer diameter D3.5, inner diameter d2.2, height h0.4), which is placed in a nitrogen atmosphere mesh belt furnace for brazing. The brazing temperature of LR660-1 is 660℃; the brazing temperature of LR660-2 needs to be 700℃; it is obvious that the alumina component of the crucible, which increases the glass melting temperature, is fused into the glass powder.

[0038] Example 2

[0039] The chemical composition of borate glass powders LR760-1 and LR760-2 is the same. The chemical composition (mass percentage) is: K₂O + Na₂O: 2.7%; B₂O₃: 29.3%; ZnO: 36.8%; Al₂O₃: 3.3%; SiO₂: 21.5%; BaO: 6.4%. The raw material composition of borate glass powder LR760-1 is as follows: Heavy zinc borate: 51%; Heavy zinc oxide powder: 14%; Barium metaborate powder: 10%; Fused quartz powder: 9%; Potassium feldspar powder: 16%.

[0040] The raw material composition of borate glass powder LR760-2 is as follows: Light zinc borate: 51%; Light zinc oxide powder: 14%; Barium metaborate powder: 10%; Fused quartz powder: 9%; Potassium feldspar powder: 16%.

[0041] Process flow: 1. Raw material mixing; 2. Raw material drying and calcination (800℃); 3. Crushing and ball milling; 4. Powdered material is placed in a corundum crucible and melted at high temperature to form glass; 5. Glass body is removed and rapidly cooled and crushed; 6. Glass sand is dried and ball-milled into powder; 7. Glass powder is granulated by sieving; 8. Dry pressing is formed into solder rings; 9. Solder rings are sintered and hardened at high temperature (aging); 10. Kovar shell, glass and solder rings are assembled into a clear window and brazed at high temperature in a mesh belt furnace; 11. Strength testing, etc.

[0042] In an LR760-1, boron trioxide and zinc oxide are added with heavy zinc borate, heavy zinc oxide and barium metaborate. After being calcined and ball-milled into powder, the powder is placed in a corundum crucible cup and melted in a high-temperature box furnace at 1350°C for two hours to be melted into a liquid. Another type of LR760-2 uses light zinc borate and light zinc oxide. After being ball-milled into powder, the powder is placed in a corundum crucible and melted in a high-temperature box furnace at 1080°C for two hours until it becomes liquid.

[0043] After LR760-1 and LR760-2 are melted, they are poured out, rapidly cooled, crushed, and ball-milled into powder.

[0044] After the crucibles cooled, the corundum crucible containing LR760-1 material was inspected, and corrosion grooves with a depth of more than 1 mm were found on the inner wall. The corundum crucible containing LR760-2 material was inspected, and no obvious corrosion grooves were found on the inner wall.

[0045] Solder rings made from LR760-1 and LR760-2 glass powders were dry-pressed and aged before being assembled with a 4J29 Kovar housing and a sapphire glass plate to form an optical window (as shown in the attached image). Figure 1 As shown, 20 is a 4J29 Kovar shell, 10 is glass solder, and 30 is a sapphire glass sheet (outer diameter D3.5, inner diameter d2.2, height h0.4), which is placed in a nitrogen atmosphere mesh belt furnace for brazing. The brazing temperature of LR660-1 is 760℃; the brazing temperature of LR660-2 needs to be 780℃; it is obvious that the alumina component of the crucible, which increases the glass melting temperature, has been incorporated into the glass powder.

[0046] This invention uses nano-lightweight borate powders, such as nano-lightweight zinc borate powder, to replace micron-sized heavy raw material powders. Borate-sealed glass can be melted at 900-1100℃. It can be melted using inexpensive corundum ceramic crucibles, and the crucibles do not show obvious corrosion.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-temperature melting borate sealing glass powder, characterized in that, The composition by mass percentage includes the following components: alkali metal oxides: 0-10%; transition metal oxides: 3-60%; B2O3: 10-45%; Al2O3: 0-9%; SiO2: 0-29%; other metal oxides: 0-20%.

2. The low-temperature melting borate sealing glass powder as described in claim 1, characterized in that, The composition includes the following components by mass percentage: B2O3: 39.7%; ZnO: 47.9%; CuO: 9%; SiO2: 3.4%.

3. The low-temperature melting borate sealing glass powder as described in claim 1, characterized in that, The composition by mass percentage includes: K₂O and / or Na₂O: 2.7%; B₂O₃: 29.3%; ZnO: 36.8%; Al₂O₃: 3.3%; SiO₂: 21.5%; BaO: 6.4%.

4. A method for preparing low-temperature melting borate sealing glass powder as described in any one of claims 1-3, characterized in that, Includes the following steps: 1) Mix the raw materials; 2) Dry and calcine the raw materials; 3) Crush and ball-mill the calcined raw materials to obtain powder; 4) Melt the powder at high temperature to make glass; 5) Quickly cool and crush the glass; 6) Dry and ball-mill the crushed glass sand into powder.

5. The method for preparing low-temperature melting borate sealing glass powder as described in claim 4, characterized in that, The raw materials in step 1) include, by mass percentage: Potassium feldspar powder: 0-50%; spodumene powder: 0-30%; lithium carbonate: 0-10%; boric acid: 0-20%; zinc borate: 10-80%; lithium borate: 0-10%; zinc oxide: 0-20%; calcium carbonate: 0-20%; quartz powder: 0-20%; kaolin: 0-20%; other metal oxides: 0-10%.

6. The method for preparing low-temperature melting borate sealing glass powder as described in claim 4, characterized in that, In step 2), the calcination temperature is 800℃.

7. The method for preparing low-temperature melting borate sealing glass powder as described in claim 4, characterized in that, In step 4), the melting temperature is 900-1100℃.

8. A solder, characterized in that, It is obtained by dry pressing of low-temperature melting borate sealing glass powder as described in any one of claims 1-3, followed by high-temperature sintering and hardening.

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