A forming die for a quartz oval tube and its processing technology

Abstract

The present invention belongs to the field of semiconductor material processing technology, and in particular relates to a forming mold for a quartz oval tube and a processing technology thereof. The forming mold comprises: a mold base; a mold cavity, disposed on the mold base, having a chamber adapted to the end face of the circular portion of the quartz oval tube; a core, disposed above the mold cavity, and divided into an upper core and a lower core, the lower core being movable in a vertical direction, the upper end face of the upper core and the lower end face of the lower core both having arc-shaped surfaces adapted to the end face of the circular portion of the quartz oval tube; wherein, after the quartz round tube is sleeved on the upper and lower cores and heated, the lower core is stretched downward by gravity to form the quartz round tube in the mold cavity.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor material processing, and in particular relates to a forming die for a quartz oval tube and a processing technology thereof. Background Art

[0002] my country's semiconductor industry is currently experiencing rapid growth. Quartz products, as core components of semiconductor equipment, serve as wafer carriers, process reaction chambers, cleaning vessels, and more. Their quality is directly related to the wafer manufacturing yield. Currently, the processing technology for quartz round tubes is relatively mature, with a wide variety of specifications available on the market. Quartz oval tubes are more complex to manufacture than round tubes, requiring large-scale equipment combined with molds. This results in high processing costs, and the core technology is mastered by very few domestic and foreign companies.

[0003] The existing Chinese utility model patent with publication number CN207811555U discloses an elliptical tube forming machine including: a turntable machine, a mold, a quartz tube to be processed, a quartz lamp, a traction bracket, a traction wire, a vacuum suction hole, and a lamp lathe body. A turntable machine is provided above the lamp lathe body, and the two ends of the quartz tube to be processed are clamped on the turntable machine. The mold is passed through the inside of the quartz tube to be processed. The quartz lamp is arranged on a slide at the top of the lamp lathe body, and the quartz lamp slides along the slide. One end of the turntable machine is sealed, and the other end is provided with a vacuum suction hole. The end of the turntable machine with the vacuum suction hole is provided with a traction wire, and the traction wire is connected to the traction bracket, and the traction bracket is provided at one end of the lamp lathe body.

[0004] The existing technology is complex, with high processing costs, limited production capacity, and unreliable quality. During product research and final testing, we discovered that the surface of the product contained high levels of metal impurities and grease, as well as low cleanliness. Summary of the Invention

[0005] The purpose of the present invention is to provide a forming die for a quartz oval tube and a processing technology thereof to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, the following technical solutions are provided: On the one hand, a forming mold for a quartz oval tube is provided, the forming mold comprising:

[0007] mold base;

[0008] a mold cavity, provided on the mold base, having a chamber adapted to the end surface of the circular portion of the quartz elliptical tube;

[0009] A core is provided above the mold cavity and is divided into an upper core and a lower core. The lower core is movably provided in a vertical direction. The upper end surface of the upper core and the lower end surface of the lower core both have arc-shaped surfaces adapted to the end surface of the circular portion of the quartz elliptical tube.

[0010] Among them, after the quartz round tube is sleeved on the upper core and the lower core and is heated, the lower core stretches the quartz round tube downward in a gravity stretching manner and is formed on the cavity of the mold cavity.

[0011] In this technical solution, the molding mold is mainly composed of a mold cavity and a mold core. The quartz round tube is stretched by utilizing gravity without the help of other external forces. It is only necessary to install the quartz round tube on the molding mold, and then send the molding mold into the heating furnace for heating. It is very convenient. The quartz oval tube processed by this method is not only high in precision, but also has no stretching scratches on the surface and a high yield rate.

[0012] In the above technical solution, further comprising:

[0013] Two guide pillars are vertically arranged and are respectively arranged on both sides of the cavity;

[0014] Wherein, the two ends of the upper core are respectively supported by the two guide pillars, and the two ends of the lower core are respectively slidably arranged on the two guide pillars along the vertical direction.

[0015] In this technical solution, when the quartz oval tube is formed, the upper core is fixed, and the lower core causes the quartz tube to be stretched under the action of its gravity. Therefore, the upper core is supported by setting a guide column, and the lower core can move downward smoothly and accurately under the guidance of the guide column.

[0016] In any of the above technical solutions, further, the lower end surface of the upper core is provided with a boss, and the upper end surface of the lower core is provided with a groove for the boss to be embedded;

[0017] Alternatively, the upper end surface of the lower core is provided with a boss, and the lower end surface of the upper core is provided with a groove for the boss to be embedded.

[0018] In this technical solution, since the inner diameter of the raw quartz tube is slightly larger than the total outer diameter of the upper core and the lower core when the mold is closed, in order to facilitate the installation of the quartz tube, the upper core and the lower core are assembled and set up. Specifically, a plug-in method is adopted so that the two can be accurately aligned and molded.

[0019] In any of the above technical solutions, further, the upper end surface of the upper core is provided with blocking portions located on both sides of its arcuate surface, and the blocking portions are higher than the arcuate surface to limit the two ends of the quartz sleeve.

[0020] In this technical solution, by setting a blocking part, after the quartz tube is installed on the upper core and the lower core, it can limit the quartz tube to prevent the quartz tube from being misplaced during stretching, thereby improving the stretching accuracy.

[0021] In any of the above technical solutions, further comprising:

[0022] There are two groups of counterweight blocks, which are respectively arranged at both ends of the lower core and are used to increase the pressure of the lower core on the quartz tube.

[0023] An insertion slot is provided at the side end of the counterweight block, and the counterweight block is sleeved on the end of the lower core through the insertion slot; a handle is also provided on the counterweight block.

[0024] In this technical solution, if the lower core is set too heavy, it will be more laborious to install the quartz tube on it. If it is set too light, it will be difficult to stretch the quartz tube during stretching. For this purpose, two detachable counterweights are provided, which can effectively reduce the weight of the lower core. In addition, two counterweights are provided to facilitate the staff to carry and operate.

[0025] On the other hand, a processing technology for a quartz oval tube is also provided, and the steps of the processing technology are specifically as follows:

[0026] (a) Blanking: Select a quartz tube of a certain specification as the blank;

[0027] (b) Boiling and cleaning: Perform an appearance inspection on the quartz tube blanks and clean the qualified blanks;

[0028] (c) Engineering cleaning: pre-processing of the quartz tube blank;

[0029] (d) die stretching: using the forming die as described in any one of claims 2 to 6 to process the quartz round tube blank after cleaning in step (c) to form a quartz oval tube;

[0030] (e) Engineering inspection: inspect the size and appearance of the quartz oval tube;

[0031] (f) Engineering cleaning: repeat step (c);

[0032] (g) Fire polishing: After the quartz oval tube is cleaned in step (c), the outer end surface and end surface of the product are flame polished with a spray gun;

[0033] (h) Annealing: Place the polished quartz oval tube on an annealing fixture and then send it into an annealing furnace for annealing. After a period of time, take out the quartz oval tube and check its stress. The residual stress is required to be ≤7° / cm, otherwise the annealing operation needs to be repeated;

[0034] (i) Final inspection: Check the size and appearance of the quartz oval tube;

[0035] (j) Final cleaning: Repeat step (c) for the quartz oval tube that has passed the inspection.

[0036] In any of the above technical solutions, further, the boiling and cleaning in step (b) includes the following steps:

[0037] (b1) Appearance inspection: Inspect the quartz tube blank to ensure that there are no cracks, gaps, or dirt defects on the appearance;

[0038] (b2) Primary cleaning: Place the quartz tube blank into a rinse tank, clean it with a detergent, and rinse it with ultrapure water;

[0039] (b3) Secondary cleaning: The rinsed quartz tube blank is placed in a heating tank for boiling and cleaning. The heating tank contains ultrapure water at a temperature of above 90°C. After a period of time, the quartz tube blank is removed and rinsed with ultrapure water in a rinsing tank. The cleaned quartz tube blank is then dried.

[0040] (b4) Appearance inspection: Inspect the cleaned and dried quartz tube blank to confirm that there is no dirt residue on its end surface before proceeding to the next process.

[0041] In any of the above technical solutions, further, the step (c) engineering cleaning includes the following steps:

[0042] (c1) Degreasing and cleaning: After step (b4), the entire quartz tube blank is scrubbed with a degreasing liquid;

[0043] (c2) Cleaning: Rinse the degreased quartz tube blank with ultrapure water to ensure that no degreasing liquid remains;

[0044] (c3) Nitric acid cleaning: Place the quartz tube blank into a nitric acid solution tank and soak for a period of time;

[0045] (c4) Rinsing: Place the quartz tube blank in an ultrapure water tank and rinse for 5 to 30 seconds;

[0046] (c5) Hydrofluoric acid cleaning: Place the quartz tube blank into a hydrofluoric acid solution tank and soak for a period of time;

[0047] (c6) Cleaning: Rinse the quartz tube blank after soaking.

[0048] In any of the above technical solutions, further, in step (d) the die stretching forming comprises the following steps:

[0049] (d1) Loading: The cleaned quartz tube blank in step (c) is placed on the upper and lower cores, and then the upper and lower cores and the quartz tube blank are lifted and placed on two guide pins. The guide pins pass through the lower core and rest on the upper core. At this time, the distance between the lower core and the cavity of the mold forms the stretched length of the quartz tube;

[0050] (d2) Gravity stretching: Place the entire forming mold in a high-temperature furnace and heat the quartz round tube blank so that it can deform. Under the external force of the lower core acting on the quartz round tube blank, the quartz round tube blank gradually deforms, and its upper part sticks to the curved surface of the upper core, and its lower part is gradually pulled down and stuck to the cavity of the cavity. After complete forming, the forming mold and the formed quartz oval tube are taken out.

[0051] The beneficial effects of the present invention are:

[0052] 1. The quartz round tube is stretched by using gravity without the help of other external forces. It is only necessary to install the quartz round tube on the forming mold, and then send the forming mold into the heating furnace for heating. It is very convenient. The quartz oval tube processed by this method is not only high in precision, but also has no stretching scratches on the surface and a high yield rate.

[0053] 2. Compared with existing technologies, the processing technology has the advantages of simplified structure, reduced costs, increased production capacity, quality assurance, and environmental protection. It can provide high-quality and high-efficiency products to meet market demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a structural diagram of a quartz tube;

[0055] Figure 2 It is a structural diagram of a quartz elliptical tube;

[0056] Figure 3 This is a schematic structural diagram of the quartz tube of the present invention being assembled on a forming mold;

[0057] Figure 4 This is a schematic structural diagram of the quartz oval tube of the present invention after being formed on a forming mold;

[0058] Figure 5 This is a schematic structural diagram of the quartz tube of the present invention being assembled on a forming mold;

[0059] Figure 6It is a structural schematic diagram of the present invention after the core is molded;

[0060] Figure 7 It is a structural schematic diagram of the core of the present invention after mold opening;

[0061] Figure 8 It is a structural schematic diagram of the return fixture of the present invention;

[0062] Figure numerals: 1, quartz round tube; 2, quartz oval tube; 10, annealing jig; 100, mold base; 200, cavity; 210, chamber; 300, core; 310, upper core; 311, blocking part; 320, lower core; 330, curved surface; 340, boss; 350, groove; 400, guide column; 500, counterweight; 510, insertion slot; 520, handle. DETAILED DESCRIPTION

[0063] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0064] In the description of this application, it should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the technologies, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0065] Example 1:

[0066] like Figure 1-Figure 7 As shown, this embodiment provides a forming mold for a quartz oval tube, and the forming mold includes:

[0067] Die base 100;

[0068] The mold cavity 200 is provided on the mold base 100 and has a chamber 210 adapted to the end surface of the circular portion of the quartz oval tube 2;

[0069] The core 300 is disposed above the mold cavity 200 and is divided into an upper core 310 and a lower core 320. The lower core 320 is movably disposed in the vertical direction. The upper end surface of the upper core 310 and the lower end surface of the lower core 320 both have an arc surface 330 adapted to the end surface of the circular portion of the quartz oval tube 2.

[0070] Among them, after the quartz tube 1 is sleeved on the upper core 310 and the lower core 320 and is heated, the lower core 320 stretches the quartz tube 1 downward by gravity stretching and is formed on the cavity 210 of the cavity 200.

[0071] In the present technical solution, the production method of quartz oval tubes is currently mainly to use quartz round tubes, that is, the quartz material is first processed into a round tube, and then stretched into the required elliptical shape by stretching. In view of some problems existing in the existing forming molds for producing quartz oval tubes, such as complicated equipment, inconvenient operation, etc., based on this, the inventor has developed a special mold, which is mainly composed of a cavity 200 and a core 300. The quartz round tube is stretched by utilizing gravity without the help of other external forces. It is only necessary to install the quartz round tube on the forming mold, and then send the forming mold into a heating furnace for heating. It is very convenient. The quartz oval tube processed by this method is not only high in precision, but also has no stretching scratches on the surface and a high yield rate.

[0072] In this embodiment, it also includes:

[0073] Two guide pillars 400 are vertically arranged and are respectively arranged on both sides of the cavity 200;

[0074] The two ends of the upper core 310 are respectively supported by the two guide pillars 400 , and the two ends of the lower core 320 are respectively slidably disposed on the two guide pillars 400 along a vertical direction.

[0075] In this technical solution, when the quartz oval tube is formed, the upper core 310 is fixed, and the lower core 320 causes the quartz tube to be stretched under the action of its gravity. Therefore, the upper core 310 is supported by setting a guide column 400, and the lower core 320 can move downward smoothly and accurately under the guidance of the guide column 400. Compared with the existing stretching method using mechanical structures such as guide rails and motors, the cost is reduced linearly.

[0076] Example 2:

[0077] This embodiment provides a forming mold for a quartz elliptical tube, which, in addition to the technical solutions of the above embodiments, also has the following technical features.

[0078] like Figure 6 and Figure 7 As shown, in this embodiment, the lower end surface of the upper core 310 is provided with a boss 340, and the upper end surface of the lower core 320 is provided with a groove 350 for the boss 340 to be embedded;

[0079] Alternatively, the upper end surface of the lower core 320 is provided with a boss 340 , and the lower end surface of the upper core 310 is provided with a groove 350 for the boss 340 to be embedded in.

[0080] In this technical solution, since the inner diameter of the raw quartz tube is slightly larger than the total outer diameter of the upper core 310 and the lower core 320 when they are molded together, in order to facilitate the installation of the quartz tube, the upper core 310 and the lower core 320 are assembled and set. Specifically, a plug-in method is adopted so that the two can be accurately aligned and molded together.

[0081] Furthermore, in order to facilitate the opening and closing of the molds, the sides of the boss 340 and the groove 350 may each have a 1° demoulding slope.

[0082] Example 3:

[0083] This embodiment provides a forming mold for a quartz elliptical tube, which, in addition to the technical solutions of the above embodiments, also has the following technical features.

[0084] like Figure 6 As shown, in this embodiment, the upper end surface of the upper core 310 is further provided with blocking portions 311 located on both sides of its arc surface 330. The blocking portions 311 are higher than the arc surface 330 to limit the two ends of the quartz sleeve.

[0085] In this technical solution, by setting the blocking part 311, after the quartz tube is installed on the upper core 310 and the lower core 320, it can limit the quartz tube to prevent the quartz tube from being misaligned during stretching, thereby improving the stretching accuracy.

[0086] Example 4:

[0087] This embodiment provides a forming mold for a quartz elliptical tube, which, in addition to the technical solutions of the above embodiments, also has the following technical features.

[0088] like Figure 3-Figure 5 As shown, in this embodiment, it also includes:

[0089] There are two groups of counterweights 500 , which are respectively disposed at both ends of the lower core 320 , and are used to increase the pressure exerted by the lower core 320 on the quartz tube.

[0090] In the present technical solution, with respect to the lower core 320, if it is set too heavy, it will be more laborious to install the quartz tube thereon; if it is set too light, it will be difficult to stretch the quartz tube during stretching. For this purpose, two detachable counterweight blocks 500 are provided, which can effectively reduce the weight of the lower core 320, and the provision of two counterweight blocks 500 can facilitate the carrying and operation of the staff.

[0091] Specifically, the side end of the counterweight 500 is provided with an insertion slot 510, through which the counterweight 500 is inserted into the end of the lower core 320, and is connected by plugging, which facilitates assembly and disassembly. The counterweight 500 is also provided with a handle 520. The handle 520 is provided to facilitate staff transportation.

[0092] Example 4:

[0093] This embodiment provides a processing technology for a quartz oval tube, and the steps of the processing technology are as follows:

[0094] (b) Cutting: Select a quartz tube of a certain specification as the blank.

[0095] (b) Boiling and cleaning: Perform an appearance inspection on the quartz tube blanks and clean the qualified blanks.

[0096] (c) Engineering cleaning: pre-processing of the quartz tube blank.

[0097] (d) Mold stretching: The quartz round tube blank after cleaning in step (c) is processed using the molding mold as described in any one of claims 2 to 6 to form a quartz oval tube.

[0098] (e) Engineering inspection: Inspect the size and appearance of the quartz oval tube.

[0099] (f) Engineering cleaning: Repeat step (c).

[0100] (g) Fire polishing: After the quartz oval tube is cleaned in step (c), the outer end face and end face of the product are flame polished with a spray gun.

[0101] (h) Annealing: The polished quartz oval tube is placed on the annealing fixture 10 and then sent to the annealing furnace for annealing. After a period of time, the quartz oval tube is taken out and its stress is checked. The residual stress is required to be ≤7° / cm. Otherwise, the annealing operation needs to be repeated.

[0102] (i) Final inspection: Check the size and appearance of the quartz oval tube.

[0103] (j) Final cleaning: Repeat step (c) for the quartz oval tube that has passed the inspection.

[0104] This technical solution addresses the current challenges of complex structures, high processing costs, limited production capacity, and unreliable quality in existing technologies. Specifically, the products suffer from high levels of metal impurities and grease on the surface, as well as low cleanliness. To address this, the aforementioned process steps are employed to produce quartz oval tubes. The core processes are (b) boiling and cleaning, (c) engineering cleaning, and d) die stretching.

[0105] Through the steps of boiling cleaning, engineering cleaning and final cleaning, the quartz round tube blank and the final product are cleaned, which can effectively remove surface impurities and pollutants and improve the cleanliness of the product.

[0106] During the engineering cleaning and final inspection steps, the dimensions of the quartz oval tubes are inspected and controlled to ensure that the product meets the specified dimensional requirements and improve product accuracy and consistency.

[0107] Through the die stretching forming steps, the use of a forming die suitable for quartz oval tube processing can effectively control the shape and size during the forming process and improve processing efficiency and consistency.

[0108] Through steps such as fire polishing and annealing, the surface quality and mechanical properties of the product can be further improved, internal stress can be eliminated, and the stability and heat resistance of the quartz oval tube can be improved.

[0109] During the final inspection and final cleaning steps, the appearance, size and cleanliness of the quartz oval tube are inspected again to improve the reliability of product quality.

[0110] The processing of this quartz oval tube involves steps such as cleanliness control, precise dimensional control, mold application, polishing, and annealing. This results in a product with excellent cleanliness, precise dimensions, and a good surface quality. These benefits help improve product quality and consistency, meeting the high-quality requirements of the semiconductor industry for quartz oval tubes.

[0111] Specifically, in the (c) blanking step, the outer diameter circumference of the quartz round tube blank is required to be slightly smaller than the outer diameter circumference of the quartz oval tube by 5-10mm, so as to ensure that the quartz round tube blank is fully stretched during the forming and stretching process into a quartz oval tube, and the size and appearance of the product can be better guaranteed; the wall thickness of the round tube blank is required to be slightly larger than the quartz oval tube by about 0.1-0.2mm, so as to ensure that the wall thickness of the quartz round tube blank will not exceed the tolerance after being stretched into a quartz oval tube, and meet the wall thickness size requirements.

[0112] In the (b) boiling and cleaning step, (b1) visually inspect the quartz tube blank under a black background and fluorescent light, requiring the appearance to be free of defects such as cracks, gaps, dirt, etc.; (b2) place the quartz tube blank in a rinsing tank, and wipe the quartz tube blank all over with a sponge dipped in detergent, and rinse it with pure water with a resistivity of ≥15ΜΩ; (b3) place the scrubbed product in a heating tank and boil it for about 15 minutes (the pure water temperature in the heating tank is required to be above 90°C). After 15 minutes, take out the product, rinse it with pure water in the rinsing tank, and gently scrub all surfaces of the product with a sponge, and then rinse it with pure water; blow dry the product with an air gun; (b4) carefully inspect the washed and dried product under a black background and fluorescent light, and after confirming that there is no dirt remaining on the surface of the product, wrap the product with clean paper and transfer it to the next step.

[0113] In the process cleaning step (c), after step (b4), the entire quartz tube blank is scrubbed with a degreasing liquid;

[0114] (c2) Cleaning: Rinse the degreased quartz tube blank with ultrapure water to ensure that no degreasing liquid remains;

[0115] (c3) Nitric acid cleaning: Soak the quartz tube blank in a 10% nitric acid solution at 25°C for 20 minutes;

[0116] (c4) Rinse: Place the quartz tube blank into a pure water tank with a resistivity of ≥15MΩ and rinse for 5 to 30 seconds;

[0117] (c5) Hydrofluoric acid cleaning: Place the quartz tube blank into a hydrofluoric acid solution tank and soak for a period of time;

[0118] (c6) Cleaning: Rinse the quartz tube blank after soaking.

[0119] In the (d) die stretching step, as Figure 1-Figure 7 As shown, (d1) loading: the quartz tube blank cleaned in step (c) is put on the upper core 310 and the lower core 320, and then the upper core 310, the lower core 320 and the quartz tube blank are lifted and placed on two guide pillars 400. The guide pillars 400 pass through the lower core 320 and then abut against the upper core 310. At this time, the distance between the lower core 320 and the cavity 210 of the cavity 200 forms the stretched length of the quartz tube;

[0120] (d2) Gravity stretching: The entire forming mold is placed in a high-temperature furnace to heat the quartz round tube blank so that it can be deformed. Under the external force of the lower core 320 acting on the quartz round tube blank, the quartz round tube blank gradually deforms, and its upper part is attached to the curved surface 330 of the upper core 310, and its lower part is gradually pulled down and attached to the cavity 210 of the cavity 200. After complete molding, the forming mold and the formed quartz oval tube are taken out.

[0121] In the annealing step (h), the product is inserted vertically onto the annealing jig 10 boss, as shown in FIG. Figure 8 As shown, vertical placement of the product results in relatively minimal deformation during the annealing process. A dedicated push rod is then used to push the product into the annealing furnace. When the annealing temperature reaches 1150°C (the constant annealing temperature), the timer begins. After 35 minutes of annealing, the product is removed and placed on a graphite plate to slowly cool to room temperature. After annealing, a stress gauge is used to self-check the product's stress. Residual stress must be ≤ 7° / cm; otherwise, re-annealing is required.

[0122] Compared with existing technologies, this quartz oval tube processing technology brings the following advantages and effects:

[0123] 1. Simplified structure and reduced cost: The traditional quartz oval tube processing technology is usually complicated and time-consuming, while this process avoids the complicated processing process through the mold stretching step, simplifies the processing flow, and reduces the processing cost and human resource requirements.

[0124] 2. Increased production capacity: Traditional quartz oval tube processing is limited by complex processes and restrictive equipment. This process, however, uses efficient die stretching, resulting in fast processing speeds and high stability, significantly increasing production capacity to meet large-scale demand.

[0125] 3. Guaranteed quality: Through the cleaning and final inspection steps, the size, appearance, and surface quality of the quartz oval tube are strictly inspected and controlled to ensure product quality. At the same time, mechanical property improvement and annealing treatment during the mold forming process can also improve the mechanical properties and stability of the product.

[0126] 4. Environmental protection and waste reduction: The cleaning and treatment processes in this process use environmentally friendly or high-purity solutions and liquids, reducing the impact on the environment. At the same time, mold stretching can also effectively reduce waste and the need for secondary processing, reducing resource waste.

[0127] In general, compared with existing technologies, this quartz oval tube processing technology has the advantages of simplified structure, reduced costs, increased production capacity, quality assurance, and environmental protection. It can provide high-quality and high-efficiency products to meet market demand.

[0128] The embodiments of the present application are described above in conjunction with the accompanying drawings. Unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A forming mold for a quartz oval tube, characterized in that: The forming mold comprises: Die base (100); A mold cavity (200) is provided on the mold base (100), and has a chamber (210) adapted to the end surface of the circular portion of the quartz elliptical tube; A core (300) is arranged above the mold cavity (200) and is divided into an upper core (310) and a lower core (320). The lower core (320) is movably arranged in a vertical direction. The upper end surface of the upper core (310) and the lower end surface of the lower core (320) both have an arc surface (330) adapted to the end surface of the circular portion of the quartz elliptical tube. wherein, after the quartz tube is sleeved on the upper core (310) and the lower core (320) and heated, the lower core (320) stretches the quartz tube downward by gravity and forms it on the chamber (210) of the cavity (200); Also includes: Two guide pillars (400) are vertically arranged and are respectively arranged on both sides of the cavity (200); The two ends of the upper core (310) are respectively supported by the two guide pillars (400), and the two ends of the lower core (320) are respectively slidably arranged on the two guide pillars (400) along the vertical direction.

2. A forming mold for a quartz oval tube according to claim 1, wherein the lower end surface of the upper mold core (310) is provided with a boss (340), and the upper end surface of the lower mold core (320) is provided with a groove (350) for the boss (340) to be embedded; Alternatively, the upper end surface of the lower mold core (320) is provided with a boss (340), and the lower end surface of the upper mold core (310) is provided with a groove (350) for the boss (340) to be embedded.

3. A forming mold for a quartz oval tube according to claim 1, wherein the upper end surface of the upper core (310) is further provided with blocking portions (311) located on both sides of its arcuate surface (330), and the blocking portions (311) are higher than the arcuate surface (330) to limit the two ends of the quartz sleeve.

4. The forming mold for a quartz oval tube according to claim 1, characterized in that: Also includes: The counterweight blocks (500) have two groups and are respectively arranged at both ends of the lower mold core (320) to increase the pressure exerted by the lower mold core (320) on the quartz tube.

5. A forming mold for a quartz oval tube according to claim 4, wherein an insertion groove (510) is provided at a side end of the counterweight block (500), and the counterweight block (500) is sleeved on the end of the lower core (320) through the insertion groove (510); and a handle (520) is also provided on the counterweight block (500).

6. A processing technology for a quartz oval tube, characterized in that: The steps of the processing technology are as follows: (a) Blanking: Select a quartz tube of a certain specification as the blank; (b) Boiling and cleaning: Perform an appearance inspection on the quartz tube blanks and clean the qualified blanks; (c) Engineering cleaning: pre-processing of the quartz tube blank; (d) die stretching: using the forming die as described in any one of claims 1 to 5 to process the quartz round tube blank after cleaning in step (c) to form a quartz oval tube; (e) Engineering inspection: inspect the size and appearance of the quartz oval tube; (f) Engineering cleaning: repeat step (c); (g) Fire polishing: After the quartz oval tube is cleaned in step (c), the outer end surface and end surface of the product are flame polished with a spray gun; (h) Annealing: Place the polished quartz oval tube on the annealing fixture (10), and then send it into the annealing furnace for annealing. After a period of time, take out the quartz oval tube and check its stress. The residual stress is required to be ≤7° / cm, otherwise the annealing operation needs to be repeated; (i) Final inspection: Check the size and appearance of the quartz oval tube; (j) Final cleaning: Repeat step (c) for the quartz oval tube that has passed the inspection; The step (d) of die stretching molding includes the following steps: (d1) Loading: The quartz tube blank cleaned in step (c) is placed on the upper core (310) and the lower core (320), and then the upper core (310), the lower core (320) and the quartz tube blank are lifted and placed on two guide pillars (400). The guide pillars (400) pass through the lower core (320) and then rest on the upper core (310). At this time, the distance between the lower core (320) and the chamber (210) of the cavity (200) forms the stretched length of the quartz tube; (d2) Gravity stretching: The entire forming mold is placed in a high-temperature furnace to heat the quartz round tube blank so that it can be deformed. Under the external force of the lower core (320) acting on the quartz round tube blank, the quartz round tube blank gradually deforms, and its upper part is attached to the curved surface (330) of the upper core (310), and its lower part is gradually pulled down and attached to the cavity (210) of the cavity (200). After complete molding, the forming mold and the formed quartz oval tube are taken out.

7. The processing technology according to claim 6, characterized in that: The boiling and cleaning step (b) comprises the following steps: (b1) Appearance inspection: Inspect the quartz tube blank to ensure that there are no cracks, gaps, or dirt defects on the surface; (b2) Primary cleaning: Place the quartz tube blank into a rinse tank, clean it with a detergent, and rinse it with ultrapure water; (b3) Secondary cleaning: The rinsed quartz tube blank is placed in a heating tank for boiling and cleaning. The heating tank contains ultrapure water at a temperature of above 90°C. After a period of time, the quartz tube blank is taken out and rinsed with ultrapure water in a rinsing tank. The cleaned quartz tube blank is then dried. (b4) Appearance inspection: Inspect the cleaned and dried quartz tube blank to confirm that there is no dirt residue on its end surface before proceeding to the next process.

8. The processing technology according to claim 6, characterized in that: The cleaning process in step (c) includes the following steps: (c1) Degreasing and cleaning: After step (b4), the entire quartz tube blank is scrubbed with a degreasing liquid; (c2) Cleaning: Rinse the degreased quartz tube blank with ultrapure water to ensure that there is no degreasing liquid residue; (c3) Nitric acid cleaning: Place the quartz tube blank into a nitric acid solution tank and soak for a period of time; (c4) Rinse: Place the quartz tube blank in an ultrapure water tank and rinse for 5 to 30 seconds; (c5) Hydrofluoric acid cleaning: Place the quartz tube blank into a hydrofluoric acid solution tank and soak for a period of time; (c6) Cleaning: Rinse the quartz tube blank after soaking.

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