Integrated circuit test equipment

Abstract

The utility model relates to the technical field of circuit element detection, and provides integrated circuit test equipment which comprises a machine body, the machine body is provided with a heating cavity, and the heating cavity is provided with an opening part; the placing rack is arranged in the heating cavity in a circulating conveying manner and is used for placing an integrated circuit board; the detection piece ascends and descends relative to the machine body, horizontally slides and is located on one side of the opening part. By means of the technical scheme, the problems that in the prior art, operation is tedious and efficiency is low in the production and quality detection process of an integrated circuit are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit element detection technical field, specifically, relate to a kind of integrated circuit test equipment. BACKGROUND

[0002] In the production and quality detection process of integrated circuits, it is crucial to ensure their performance stability under high temperature environment. However, the existing technical means usually first uses a special heating equipment to uniformly heat a batch of integrated circuit boards, and then takes out these circuit boards one by one after heating, and then uses a separate detection equipment to test the performance. This traditional operation method has obvious defects. First of all, the whole process is divided into two independent steps of heating and detection, which needs to transfer the circuit boards between different devices, not only complicated operation, but also easy to damage the circuit boards during the transfer process. Secondly, the way of taking out and testing individually is extremely inefficient, which is difficult to meet the needs of large-scale production and rapid detection. In addition, due to the time interval between heating and detection, the temperature of the circuit board may drop after being taken out, which affects the accuracy of the test results. Moreover, the time interval between heating and detection may be inconsistent for different batches of circuit boards, further increasing the uncertainty of the test results. SUMMARY

[0003] The utility model provides a kind of integrated circuit test equipment, solve the problem of complicated operation and low efficiency in the production and quality detection process of integrated circuits in relevant technologies.

[0004] The technical scheme of the utility model is as follows:

[0005] An integrated circuit test equipment for heating test of integrated circuit boards, comprising:

[0006] A machine body having a heating cavity with an opening portion;

[0007] A placing rack for placing the integrated circuit boards, which is circularly conveyed in the heating cavity;

[0008] A detection piece that is vertically movable and horizontally slidable relative to the machine body and located on one side of the opening portion, and the inner wall of the heating cavity has a first annular guide groove.

[0009] As a further technical solution, it further comprises:

[0010] A sliding guide piece arranged on the side wall of the placing rack, which is slidingly arranged in the first annular guide groove.

[0011] As a further technical solution, the first annular guide groove has an inner ring groove and an outer ring groove, the outer ring groove is located at the periphery of the inner ring groove, and the sliding guide has a first sliding part and a second sliding part, the first sliding part and the second sliding part are respectively arranged in the outer ring groove and the inner ring groove.

[0012] As a further technical solution, the opening part is located at the top of the heating cavity, the inner ring groove and the outer ring groove each have an equidistant section and a junction section, the equidistant sections and the junction sections are arranged in pairs and alternately connected head to tail, the equidistant sections of the inner ring groove and the outer ring groove are parallel to each other, and the inner ring groove and the outer ring groove are used to make the placing rack parallel to the bottom surface of the machine body.

[0013] The working principle and beneficial effects of the utility model are as follows:

[0014] In the utility model, the integrated circuit board to be tested is accurately placed in the positioning groove of the placing rack. The device is started, and the placing rack is uniformly and circularly conveyed in the heating cavity by the synchronous belt. After the placing rack circularly conveys the integrated circuit board for one turn, it is accurately stopped at the position of the opening part. At this time, the detection part is lowered by the electric push rod, is simultaneously horizontally slid to the upper side of the opening part along the linear guide rail, and is close to the integrated circuit board to perform performance detection. After detection is completed, the detection part is raised and is horizontally slid to reset, and waits for the detection of the next integrated circuit board. The mode that the placing rack is circularly conveyed for one turn and detection is performed improves production rhythm and significantly improves work efficiency. The integrated circuit board is uniformly and sufficiently heated in the heating cavity, stable temperature conditions are provided for accurate detection. The sealing structure of the opening part effectively reduces heat loss, reduces energy consumption, and saves production cost. Stable detection conditions and accurate operation process help to improve the accuracy and consistency of detection results, thereby guaranteeing product quality. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above characteristics, technical features, advantages and implementation modes of the utility model will be further described in the following preferred embodiments combined with the drawings.

[0016] Figure 1 It is a structural schematic diagram of the utility model;

[0017] Figure 2 It is a structural schematic diagram of the utility model;

[0018] Figure 3 It is another internal structure schematic diagram of the utility model from another perspective;

[0019] Figure 4 It is Figure 2 It is a partial enlarged structural schematic diagram of A part in the utility model;

[0020] Figure 5 For Figure 3 Local enlarged structure diagram of middle B part.

[0021] In the figure: integrated circuit board-1, edge-101, body-2, heating cavity-201, opening part-202, first annular guide groove-203, inner ring groove-204, outer ring groove-205, equidistant section-206, intersection section-207, outer arc part-208, detection piece-3, sliding guide-4, first sliding part-401, second sliding part-402, third sliding part-403, fourth sliding part-404, feeding rack-5, discharging rack-6, first top piece-7, second top piece-8, third top piece-9, fourth top piece-10, clamping part-1001, fifth top piece-11, sixth top piece-12, placing rack-19. DETAILED DESCRIPTION

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the specific embodiments of the present application will be described below with reference to the drawings. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without creative labor, and other embodiments can also be obtained.

[0023] In order to make the drawing simple, only the parts related to the present application are shown in each drawing, which does not represent the actual structure of the product. In addition, in order to make the drawing simple and easy to understand, in some drawings, only one of the parts with the same structure or function is shown, or only one of them is marked. In this paper, "one" not only means "only one", but also means "more than one", and "several" includes "two" and "more than two".

[0024] In this paper, it should be noted that unless otherwise specified and limited, the terms "mounting", "connection" and "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] In addition, in the description of the present application, the terms "first", "second" and the like are only used for distinction and description, and cannot be understood as indicating or implying relative importance.

[0026] Reference Figures 1-5The utility model provides a kind of integrated circuit test equipment, for heating test to integrated circuit board 1, including body 2, body 2 has heating cavity 201, heating cavity 201 has opening part 202;Placement rack 19 circulation is transported in heating cavity 201, and placement rack 19 is used to place integrated circuit board 1;Detection piece 3 is arranged relative to body 2 lifting and horizontal sliding, and located in the side of opening part 202.

[0027] In the embodiment, heating cavity 201 is internally provided with uniformly distributed heating elements, such as resistance wires, and the cavity wall is made of heat insulation materials, such as asbestos. Placement rack 19 is made of high-temperature-resistant metal materials, such as stainless steel, and is provided with positioning grooves on the surface to fix integrated circuit board 1. Placement rack 19 is circulated and transported in heating cavity 201 by a chain and sprocket transmission system. Detection piece 3: including probe, sensor and other detection elements, installed on a liftable and horizontally slidable mechanical structure, driven by a motor. The integrated circuit board 1 to be tested is accurately placed in the positioning groove of the placement rack 19. Start the device, and the placement rack 19 is uniformly circulated and transported in the heating cavity 201 by the synchronous belt. After the placement rack 19 circulates and transports the integrated circuit board 1 for one round, it is accurately stopped at the position of the opening part 202. At this time, the detection piece 3 is lowered by the electric push rod, and is horizontally slid along the linear guide rail to above the opening part 202 and close to the integrated circuit board 1 for performance detection. After detection, the detection piece 3 is lifted and horizontally slid to reset, waiting for the detection of the next integrated circuit board 1. The circulation of the placement rack 19 for one round improves the production rhythm and significantly improves the work efficiency. It ensures that the integrated circuit board 1 is evenly and fully heated in the heating cavity 201, providing stable temperature conditions for accurate detection. The sealing structure of the opening part 202 effectively reduces heat loss, reduces energy consumption and saves production cost. Stable detection conditions and accurate operation process help to improve the accuracy and consistency of detection results, thereby ensuring product quality.

[0028] Further, the inner wall of the heating cavity 201 has a first annular guide groove 203, and further includes a sliding guide 4 arranged on the side wall of the placement rack 19, which is slidably arranged in the first annular guide groove 203.

[0029] In this embodiment, when the placement rack 19 is circulatingly conveyed within the heating cavity 201, the sliding guide 4 on the side wall smoothly slides along the first annular guide groove 203 on the inner wall of the heating cavity 201. This sliding fit ensures the stability and directionality of the placement rack 19 during conveying, enabling it to accurately circulate according to the predetermined track, avoiding situations such as deviation, jamming, or shaking of the placement rack 19 during movement. The cooperation of the sliding guide 4 and the first annular guide groove 203 ensures the stable circulation of the placement rack 19 within the heating cavity 201, reducing the position changes of the integrated circuit board 1 caused by shaking or deviation, and ensuring the uniformity of heating and the accuracy of detection. The smooth guide groove and the wear-resistant sliding guide 4 interact to reduce the wear between components, prolonging the service life of the equipment. The placement rack 19 can strictly move according to the annular track, improving the precision and reliability of the equipment operation. Reducing the possible failures and downtime caused by unstable conveying, improving the production efficiency.

[0030] Further, the first annular guide groove 203 has an inner ring groove 204 and an outer ring groove 205, the outer ring groove 205 is located at the periphery of the inner ring groove 204, the sliding guide 4 has a first sliding part 401 and a second sliding part 402, the first sliding part 401 and the second sliding part 402 are respectively slidingly arranged in the outer ring groove 205 and the inner ring groove 204; the opening part 202 is located at the top of the heating cavity 201, the inner ring groove 204 and the outer ring groove 205 both have equidistant sections 206 and intersection sections 207, the equidistant sections 206 and the intersection sections 207 are arranged in pairs and alternately connected head to tail, the equidistant sections 206 of the inner ring groove 204 and the outer ring groove 205 are parallel to each other, and the inner ring groove 204 and the outer ring groove 205 are used to make the placement rack 19 parallel to the bottom surface of the body 2.

[0031] In this embodiment, when the placement rack 19 is circulatingly conveyed in the heating cavity 201, the first sliding part 401 of the sliding guide 4 slides in the inner ring groove 204, while the second sliding part 402 slides in the outer ring groove 205. This design of double sliding parts makes the movement of the placement rack 19 more stable and balanced, effectively preventing the inclination or shaking of the placement rack 19. The two sliding parts work cooperatively in the respective grooves, ensuring the accurate and smooth movement of the placement rack 19 along the predetermined annular trajectory. The first sliding part 401 of the sliding guide 4 tightly fits the inner ring groove 204, and the second sliding part 402 tightly fits the outer ring groove 205. Due to the joint action of the inner ring groove 204 and the outer ring groove 205, the constraint force applied to the sliding guide 4 enables the placement rack 19 to always move parallel to the bottom surface of the machine body 2. This parallel state is maintained throughout the entire circulating conveying process, regardless of the number, distribution, and conveying speed of the integrated circuit boards 1 on the placement rack 19. The arrangement of this scheme ensures that the placement rack 19 always moves parallel to the bottom surface of the machine body 2 during conveying, providing a stable heating environment for the integrated circuit boards 1 and avoiding local uneven heating caused by the inclination of the placement rack 19, thereby improving the heating effect and the accuracy of detection. The force on the placement rack 19 during movement is uniform, reducing local stress concentration caused by inclination, reducing the wear of the placement rack 19 and the guide groove, and prolonging the service life of the equipment. It ensures the consistency of the integrated circuit boards 1 at each position, helps to improve the accuracy and reliability of the detection results, and reduces errors. It can adapt to integrated circuit boards 1 of different sizes and weights, and does not affect the parallel state of the placement rack 19 due to changes in load, enhancing the versatility and practicality of the equipment. The parallel running mode enables more efficient arrangement of the placement rack 19 and the integrated circuit boards 1 in the limited heating cavity 201, improves the space utilization, and increases the production efficiency.

[0032] When the sliding guide 4 enters the equidistant section 206 during the circulation of the placing rack 19 in the heating cavity 201, the placing rack 19 remains stable and parallel to the bottom surface of the machine body 2. In the intersection section 207, the sliding guide 4 smoothly transitions due to the special design of the inner ring groove 204 and the outer ring groove 205, allowing the placing rack 19 to remain parallel. Through the alternating arrangement of the equidistant section 206 and the intersection section 207, the placing rack 19 continuously and stably circulates in the heating cavity 201, and finally accurately stops at the top of the opening part 202 for detection. The design of the equidistant section 206 and the intersection section 207 ensures that the placing rack 19 remains parallel to the bottom surface of the machine body 2 throughout the entire circulation process, providing a stable and uniform heating environment for the integrated circuit board 1 and ensuring the accuracy and reliability of the detection results. The design of the intersection section 207 makes the transition of the sliding guide 4 between different sections smooth and smooth, reducing jamming and vibration, improving the running stability and service life of the equipment. The opening part 202 is located at the top of the heating cavity 201 and the placing rack 19 can accurately and parallelly stop, which facilitates detection operation and improves detection efficiency and accuracy. This special guide groove structure can adapt to the complex movement requirements of the placing rack 19 during circulation, improving the flexibility and versatility of the equipment. Ensuring the parallel state of the placing rack 19 reduces the structural stress concentration caused by inclination or instability, enhancing the structural stability and durability of the entire device.

[0033] Further, the first annular guide groove 203 is an inner groove, the inner wall of the heating cavity 201 also has an outer arc part 208, the outer arc part 208 is located on one side of the intersection section 207 of the outer ring groove 205, and there are also two, the sliding guide 4 also has a third sliding part 403 and a fourth sliding part 404, the third sliding part 403 and the fourth sliding part 404 are configured to be moved by the placing rack 19, respectively, with the outer arc part 208 close to the opening part 202 rolling abutting or canceling abutting, and with the outer arc part 208 away from the opening part 202 rolling abutting or canceling abutting; It also includes a feeding rack 5 and a discharging rack 6, which are arranged on the machine body 2 and are located on both sides of the opening part 202 respectively, the feeding rack 5 is used to store undetected integrated circuit boards 1, and the discharging rack 6 is used to store detected integrated circuit boards 1.

[0034] In this embodiment, when the placing rack 19 circulates and transports in the heating cavity 201, the third sliding part 403 and the fourth sliding part 404 are driven with the movement of the placing rack 19. When approaching the opening part 202, the third sliding part 403 rolls against the outer arc part 208 near the opening part 202 to provide additional guidance and support; when moving away from the opening part 202, the third sliding part 403 cancels the abutment. At the same time, the fourth sliding part 404 rolls against or cancels the abutment with the outer arc part 208 away from the opening part 202 accordingly. This rolling abutment and cancellation of abutment alternately occurs according to the change of the position of the placing rack 19, ensuring the stable transition and accurate movement of the placing rack 19 in the intersection section 207. The rolling abutment of the placing rack 19 with the outer arc part 208 in the intersection section 207 provides more accurate guidance, ensuring accurate movement and positioning. The cooperation of the third sliding part 403 and the fourth sliding part 404 with the outer arc part 208 makes the transition of the placing rack 19 in the intersection section 207 more stable, reducing impact and vibration, and improving the stability of the equipment operation. The rolling abutment reduces the friction between the sliding parts, reduces wear and tear, and prolongs the service life of the parts. It ensures that the placing rack 19 remains stable during complex movement, reduces the possibility of failure, and enhances the reliability of the equipment.

[0035] The undetected integrated circuit board 1 is placed on the feeding rack 5. When the placing rack 19 reaches the opening part 202, the undetected integrated circuit board 1 is taken from the feeding rack 5 and placed on the placing rack 19, and then the placing rack 19 enters the heating cavity 201 for heating. After heating and detection, the placing rack 19 returns to the opening part 202 again to take out the detected integrated circuit board 1 and place it on the discharging rack 6. The arrangement of the feeding rack 5 and the discharging rack 6 allows the undetected and detected integrated circuit boards 1 to be stored separately, making the operation more orderly and avoiding confusion. It is convenient for the operator to quickly take and place the integrated circuit board 1, reduces the waiting time, and improves the overall detection efficiency. Make full use of the space around the machine body 2 without occupying too much additional space. The detection process is more clear, which is conducive to the management and monitoring of the detection process of the integrated circuit board 1. Reduces the risk of detection errors caused by confusion of integrated circuit boards 1.

[0036] Further, the definition of the transverse direction as the conveying direction also includes that the first top piece 7 is arranged on the feeding rack 5, and the output end moves horizontally, the moving direction is perpendicular to the conveying direction, the output end of the first top piece 7 is configured to move to abut or cancel abutment with the side edge of the integrated circuit board 1; the second top piece 8 is arranged on the feeding rack 5 below the integrated circuit board 1, the moving direction of the second top piece 8 is along the vertical direction, and the output end of the second top piece 8 is configured to move to abut the bottom of the integrated circuit board 1 and drive the integrated circuit board 1 to move upward; the third top piece 9 is arranged on the feeding rack 5 on the side away from the outlet 202 of the integrated circuit board 1, the moving direction of the output end of the third top piece 9 is along the conveying direction, and the output end of the third top piece 9 is configured to move to abut the side wall of the integrated circuit board 1 and drive the integrated circuit board 1 to move in the conveying direction.

[0037] In this embodiment, when it is necessary to place the integrated circuit board 1 on the feeding rack 5 on the placement rack 19, first, the second top piece 8 rises, and the output end of the second top piece 8 abuts the bottom of the integrated circuit board 1 and lifts it to a certain height. Then the output end of the first top piece 7 moves horizontally and abuts the side edge of the integrated circuit board 1 to position it laterally. Then the output end of the third top piece 9 moves in the conveying direction and abuts the side wall of the integrated circuit board 1 and pushes it to move in the conveying direction until the integrated circuit board 1 accurately reaches the designated position of the placement rack 19. Through the coordinated action of the first top piece 7, the second top piece 8 and the third top piece 9, the precise position adjustment of the integrated circuit board 1 on the feeding rack 5 can be realized, ensuring accurate and reliable delivery to the placement rack 19, improving the accuracy and reliability of the operation. The lifting action of the second top piece 8 and the pushing action of the third top piece 9 cooperate with each other to keep the integrated circuit board 1 stable during conveying, reducing the risk of shaking and falling. It can adapt to integrated circuit boards 1 of different sizes and shapes, and through adjusting the stroke and position of the top piece, flexible feeding operation can be realized. The buffer and anti-skid design of the top piece can minimize physical damage to the integrated circuit board 1 and ensure product quality.

[0038] Further, the fourth top piece 10 is arranged on the discharge rack 6, the moving direction of the output end of the fourth top piece 10 is horizontal and perpendicular to the conveying direction, and the output end of the fourth top piece 10 is configured to abut against or cancel the abutment with the integrated circuit board 1 after moving; the fifth top piece 11 is arranged on the discharge rack 6, the conveying direction of the output end of the fifth top piece 11 is vertical, and the output end of the fifth top piece 11 is configured to abut against the bottom of the integrated circuit board 1 after moving and drive the integrated circuit board 1 to move upward; the sixth top piece 12 is arranged on the machine body 2 between the feeding rack 5 and the discharge rack 6, the output end of the sixth top piece 12 moves along the conveying direction, abuts against the side wall of the integrated circuit board 1 after moving, and drives the integrated circuit board 1 to move towards the discharge rack 6; the side edge of the integrated circuit board 1 has a ridge 101, the first top piece 7 and the fourth top piece 10 are arranged in pairs and located on both sides of the integrated circuit board 1, and the first top piece 7 and the fourth top piece 10 both have a clamping part 1001 for abutting against the ridge 101 and providing a force for the ridge 101 to move away from the plane where the opening part 202 is located.

[0039] In the embodiment, when the integrated circuit board 1 that has completed detection is conveyed to the opening part 202, the output end of the sixth top piece 12 moves quickly along the conveying direction, the metal push plate of the sixth top piece 12 gently abuts against the side wall of the integrated circuit board 1 and stably pushes the integrated circuit board 1 to the direction of the discharge rack 6. At this time, if there are integrated circuit boards 1 that have been stacked on the discharge rack 6, the fifth top piece 11 is started. The wide metal supporting plate of the fifth top piece 11 is driven to rise, the integrated circuit boards 1 that have been stacked are lifted as a whole, and space is left for the new integrated circuit board 1 that has completed detection. The rubber push head of the output end of the fourth top piece 10 is horizontally moved by the electric push rod of the fourth top piece 10, tightly abuts against the side edge of the new integrated circuit board 1 that has completed detection, and accurately positions the new integrated circuit board 1. After positioning, the fifth top piece 11 slowly descends, the integrated circuit boards 1 that have been lifted and the new integrated circuit board 1 that has completed detection are placed stably on the discharge rack 6 together, and the new integrated circuit board 1 is located at the lowermost layer. The whole process realizes automatic operation, greatly improves the production efficiency, and reduces the time and labor intensity of manual operation. Through the accurate actions of the top pieces, the integrated circuit boards 1 are stacked neatly and accurately positioned on the discharge rack 6, which is convenient for subsequent management and transportation. In the operation process, the buffer design and soft action of the top pieces greatly reduce the impact and wear of the integrated circuit boards 1, and ensure the quality and integrity of the products. The space of the discharge rack 6 can be fully utilized to realize multi-layer and compact stacking, and the utilization rate of the storage space is improved.

[0040] When the integrated circuit board 1 needs to be pushed on the feeding rack 5, the first top piece 7 arranged in pairs acts simultaneously. The clamping part 1001 abuts against the edge 101 of the integrated circuit board 1, and exerts a force in the direction away from the plane where the outlet part 202 is located, thereby pushing the integrated circuit board 1 to make accurate position adjustment and conveying. The cooperation between the clamping part 1001 and the edge 101 can realize more accurate positioning and pushing of the integrated circuit board 1, and ensure the position accuracy of the integrated circuit board 1 during conveying and stacking. The top piece arranged in pairs can uniformly exert force on the integrated circuit board 1 from both sides, avoiding the skew or instability caused by unilateral force. The rubber or plastic material used for the clamping part 1001 has certain elasticity and buffering property, which can reduce the damage to the integrated circuit board 1 when contacting the edge 101. Since the shape of the clamping part 1001 matches the edge 101, the integrated circuit board 1 with different specifications but similar edge 101 structure can also be effectively operated, improving the versatility of the equipment. By exerting force in a specific direction, the stability of the integrated circuit board 1 during conveying and stacking is increased, and the risk of accidental movement or falling is reduced. On the discharging rack 6, after the completed integrated circuit board 1 is detected to be in place, the fourth top piece 10 arranged in pairs acts. The clamping part 1001 also abuts against the edge 101 of the integrated circuit board 1, and provides a force for the edge 101 in the direction away from the plane where the outlet part 202 is located, thereby realizing the positioning and arrangement of the integrated circuit board 1, so as to perform subsequent stacking operation.

[0041] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. An integrated circuit testing device for performing heating tests on an integrated circuit board (1), characterized in that, include: The body (2) has a heating chamber (201) and the heating chamber (201) has an opening (202). Placement rack (19), which is circulated and disposed in the heating chamber (201), is used to place the integrated circuit board (1). The detection element (3) is raised and lowered and horizontally slidable relative to the body (2) and is located on one side of the opening (202). The inner wall of the heating chamber (201) has a first annular guide groove (203).

2. The integrated circuit testing equipment according to claim 1, characterized in that, Also includes: A sliding guide (4) is disposed on the side wall of the placement frame (19) and is slidably disposed in the first annular guide groove (203).

3. The integrated circuit testing equipment according to claim 2, characterized in that, The first annular guide groove (203) has an inner annular groove (204) and an outer annular groove (205). The outer annular groove (205) is located around the inner annular groove (204). The sliding guide (4) has a first sliding part (401) and a second sliding part (402). The first sliding part (401) and the second sliding part (402) are respectively slidably disposed in the outer annular groove (205) and the inner annular groove (204).

4. An integrated circuit testing device according to claim 3, characterized in that, The opening (202) is located at the top of the heating chamber (201). The inner ring groove (204) and the outer ring groove (205) each have equidistant sections (206) and converging sections (207). The equidistant sections (206) and the converging sections (207) are arranged in pairs and alternately connected end to end. The equidistant sections (206) of the inner ring groove (204) and the outer ring groove (205) are parallel to each other. The inner ring groove (204) and the outer ring groove (205) are used to make the placement rack (19) parallel to the bottom surface of the body (2).

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