Silicon optical chip laser bonding equipment

Abstract

The invention relates to silicon optical chip laser bonding equipment which comprises a marble table board, and a feeding belt conveying belt, a discharging belt conveying belt, a welding mechanism and a feeding and discharging mechanism are arranged on the marble table board. A feeding belt conveying belt and a discharging belt conveying belt are sequentially installed at the front end of the marble table top from left to right, a welding mechanism is arranged in the middle of the rear end of the marble table top, a jig platform is arranged on the portion, in front of the welding mechanism, of the marble table top, and a feeding and discharging mechanism is arranged above the jig platform. According to the invention, laser is adopted as a heat source, a traditional reflow soldering process is replaced, and the problem of metallurgical bonding form variation caused by non-uniform heat due to temperature difference during silicon chip bonding can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field related to semiconductor chip packaging technology, and in particular to a silicon photonic chip laser bonding device. Background Art

[0002] Silicon photonic chips based on silicon CMOS technology have important and potential application value in many fields such as data transmission, optical communication, lidar, health care, etc. Flip-chip technology refers to the technology of depositing tin-lead balls on the I / O pins of the chip package, then flipping the chip and heating it, and combining the molten tin-lead balls with the substrate. Usually, pads and bump solders are made on one side of the active area of ​​the silicon chip packaging unit, and then the chip packaging unit is interconnected face down with solder and circuit board materials to form a stable and reliable mechanical and electrical connection. Among them, reflow soldering is a conventional heating technology that is simple and efficient.

[0003] Since the silicon photonic chip needs to be soldered to the PCB through the SMT surface mounting process after packaging, SMT soldering requires high-temperature soldering through reflow soldering. The deformation of the silicon photonic chip due to temperature changes during reflow soldering will affect the welding quality.

[0004] In view of the above-mentioned defects, the designers have actively carried out research and innovation in order to create a silicon photonic chip laser bonding equipment to make it more valuable for industrial use. Summary of the invention

[0005] In order to solve any of the above technical problems, the purpose of the present invention is to provide a silicon photonic chip laser bonding device.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] Silicon photonic chip laser bonding equipment, including a marble table, on which a loading belt conveyor, a unloading belt conveyor, a welding mechanism and a loading and unloading mechanism are arranged;

[0008] A loading belt conveyor and a unloading belt conveyor are installed in sequence from left to right on the front end of the marble table top, a welding mechanism is arranged in the middle of the rear end of the marble table top, a fixture platform is arranged on the marble table top in front of the welding mechanism, and a loading and unloading mechanism is arranged above the fixture platform;

[0009] The loading belt conveyor and the unloading belt conveyor are used for loading and unloading product carriers respectively; the loading and unloading mechanism is used to transport the product carrier on the loading belt conveyor to the jig platform and to transport the processed product carrier from the jig platform to the unloading belt conveyor; the welding mechanism is used to perform welding processing on the product carrier placed on the jig platform.

[0010] As a further improvement of the present invention, the welding mechanism includes a welding gantry installed on a marble table top, a welding X-axis linear module and a welding Z-axis module installed on the welding gantry respectively drive the welding moving plate to move in the X-axis and Z-axis directions, and a variable spot welding head is installed on the welding moving plate.

[0011] As a further improvement of the present invention, a CCD module, an infrared thermal imaging probe and a height meter are also installed on the welding motion board on one side of the variable spot welding head.

[0012] As a further improvement of the present invention, the jig platform includes a welding Y-axis linear module installed on a marble table top, the welding Y-axis linear module drives the upper jig module to move in the Y-axis direction through the jig platform module fixing plate, the jig module includes a multi-directional swing module installed on the jig platform module fixing plate, a jig mounting base plate is installed on the multi-directional swing module, a nitrogen-filled cavity jig is installed on the jig mounting base plate, a jig upper cover plate is arranged above the nitrogen-filled cavity jig, the jig upper cover plate moves in the Y-axis direction under the drive of the jig Y-axis module and the slide rail installed on the jig mounting base plate, and the jig upper cover plate moves in the Z-axis direction under the drive of the cover plate lifting electric cylinder.

[0013] As a further improvement of the present invention, the multi-directional swing module includes an α-axis motor module, a θ-axis motor module and a β-axis motor module.

[0014] As a further improvement of the present invention, a welding heating table is installed on the fixture mounting base plate at the bottom of the nitrogen-filled cavity fixture, and an oxygen content probe, a laser power meter installed on a power meter fixing plate, and a cavity nitrogen inlet are also installed on the fixture mounting base plate.

[0015] As a further improvement of the present invention, the loading and unloading mechanism includes a loading and unloading mechanism gantry installed on the marble table top, and the loading and unloading material handling X-axis module installed on the loading and unloading mechanism gantry respectively drives the loading and unloading components and the left and right sides to move in the X-axis direction; the loading component includes a loading and unloading material handling Y-axis module, a loading and unloading material handling Z-axis module and a material picking suction cup; the unloading component includes a unloading material handling Y-axis module, a unloading material handling Z-axis module and a unloading suction cup.

[0016] As a further improvement of the present invention, a preheating table for the waiting area is installed on the marble table between the loading belt conveyor and the loading and unloading mechanism, and a cooling unloading table is installed on the marble table between the unloading belt conveyor and the loading and unloading mechanism.

[0017] As a further improvement of the present invention, an oxygen content display meter and a preheating table controller are also installed on the marble table top.

[0018] As a further improvement of the present invention, a loading conveyor belt line blocking block is installed on the loading conveyor belt, and a unloading conveyor belt line blocking block is installed on the unloading conveyor belt.

[0019] By means of the above scheme, the present invention has at least the following advantages:

[0020] The present invention adopts laser as a heat source, replacing the traditional reflow soldering process, and can solve the problem of uneven heat caused by temperature difference during silicon chip bonding, thereby causing variation in metallurgical bonding morphology.

[0021] The fully automatic feeding process of the present invention has a high degree of automation for the entire welding, and can greatly improve the processing efficiency, processing accuracy and yield rate of chip bonding.

[0022] Compared with the traditional reflow soldering method, the present invention can greatly improve the bonding quality, ensure that there are no problems such as false solder joints and cold solder joints, and the efficiency UPH of the entire laser bonding equipment is ≥300.

[0023] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a structural schematic diagram of a silicon photonic chip laser bonding device of the present invention;

[0026] Figure 2 yes Figure 1 A top view of

[0027] Figure 3 yes Figure 1 A front view of

[0028] Figure 4 yes Figure 1 Structural diagram of the welding mechanism;

[0029] Figure 5 yes Figure 1 Schematic diagram of the structure of the middle fixture platform;

[0030] Figure 6 yes Figure 1 Schematic diagram of the structure of the middle fixture module;

[0031] Figure 7 yes Figure 1 Structural diagram of the loading and unloading mechanism;

[0032] Figure 8 It is a schematic diagram of the present invention during laser bonding;

[0033] Fig. 9 It is a schematic diagram of the temperature curve during laser bonding of the present invention.

[0034] The meanings of the various reference numerals in the figures are as follows.

[0035] Loading belt conveyor 1, unloading belt conveyor 2, welding X-axis linear module 3, welding Y-axis linear module 4, loading and handling Y-axis module 5, loading and handling Z-axis module 6, unloading and handling Y-axis module 7, unloading and handling Z-axis module 8, loading and unloading and handling X-axis module 9, variable spot welding head 10, CCD module 11, infrared thermal imaging probe 12, welding Z-axis module 13, oxygen content display table 14, oxygen content probe 15, material picking suction cup 16, unloading suction cup 17, marble table 18, nitrogen filling cavity fixture 19, product carrier 20, waiting area preheating table 21, preheating table control Device 22, cooling and unloading table 23, welding gantry 24, welding heating table 25, fixture upper cover plate 26, cover lifting electric cylinder 27, laser power meter 28, loading and unloading mechanism gantry 29, slide rail 30, α-axis motor module 31, θ-axis motor module 32, β-axis motor module 33, fixture platform module fixing plate 34, power meter fixing plate 35, fixture Y-axis module 36, cavity nitrogen inlet 37, altimeter 38, fixture installation base plate 39, loading and unloading transmission belt line blocking block 40, unloading and unloading transmission belt line blocking block 41, laser beam 42, silicon chip 43, PCB substrate 44. DETAILED DESCRIPTION

[0036] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0037] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, rather than all the embodiments. The components of the embodiment of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiment of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiment of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0038] like Figures 1 to 9 As shown, a silicon photonic chip laser bonding device includes a marble table 18, on which a loading belt conveyor 1, a unloading belt conveyor 2, a welding mechanism and an unloading mechanism are arranged. The loading belt conveyor 1 and the unloading belt conveyor 2 are installed in sequence from left to right on the front end of the marble table 18, a welding mechanism is arranged in the middle of the rear end of the marble table 18, a jig platform is arranged on the marble table 18 in front of the welding mechanism, and an unloading mechanism is arranged above the jig platform. Among them, the loading belt conveyor 1 and the unloading belt conveyor 2 are used for loading and unloading of product carriers 20 respectively, the unloading mechanism is used to transport the product carrier 20 located on the loading belt conveyor 1 to the jig platform and to transport the processed product carrier 20 from the jig platform to the unloading belt conveyor 2, and the welding mechanism is used to perform welding processing on the product carrier 20 placed on the jig platform.

[0039] The welding mechanism includes a welding gantry 24 installed on a marble table 18. The welding X-axis linear module 3 and the welding Z-axis module 13 installed on the welding gantry 24 drive the welding motion plate to move in the X-axis and Z-axis directions respectively. The variable spot welding head 10 is installed on the welding motion plate. A CCD module 11, an infrared thermal imaging probe 12 and a height meter 38 are also installed on the welding motion plate on one side of the variable spot welding head 10.

[0040] A loading conveyor belt line blocking block 40 is installed on the loading conveyor belt 1 , and a unloading conveyor belt line blocking block 41 is installed on the unloading conveyor belt 2 .

[0041] The jig platform includes a welding Y-axis linear module 4 installed on a marble table 18, and the welding Y-axis linear module 4 drives the upper jig module to move in the Y-axis direction through the jig platform module fixing plate 34. The jig module includes a multi-directional swing module installed on the jig platform module fixing plate 34, and a jig mounting base plate 39 is installed on the multi-directional swing module. A nitrogen-filled cavity jig 19 is installed on the jig mounting base plate 39, and a jig upper cover plate 26 is arranged above the nitrogen-filled cavity jig 19. The jig upper cover plate 26 moves in the Y-axis direction under the drive of the jig Y-axis module 36 and the slide rail 30 installed on the jig mounting base plate 39, and the jig upper cover plate 26 moves in the Z-axis direction under the drive of the cover plate lifting electric cylinder 27.

[0042] The multi-directional swing module includes an α-axis motor module 31 , a θ-axis motor module 32 and a β-axis motor module 33 .

[0043] A welding heating table 25 is installed on the fixture mounting base plate 39 at the bottom of the nitrogen-filled cavity fixture 19, and an oxygen content probe 15, a laser power meter 28 installed on the power meter fixing plate 35, and a cavity nitrogen inlet 37 are also installed on the fixture mounting base plate 39.

[0044] The loading and unloading mechanism includes a loading and unloading mechanism gantry 29 installed on the marble table 18, and the loading and unloading X-axis module 9 installed on the loading and unloading mechanism gantry 29 drives the loading and unloading components and the unloading components on the left and right sides to move in the X-axis direction respectively; the loading component includes a loading and unloading Y-axis module 5, a loading and unloading Z-axis module 6 and a material picking suction cup 16; the unloading component includes a unloading Y-axis module 7, a unloading Z-axis module 8 and a unloading suction cup 17.

[0045] A preheating table 21 for the waiting area is installed on the marble table 18 between the feeding belt conveyor 1 and the loading and unloading mechanism, and a cooling unloading table 23 is installed on the marble table 18 between the unloading belt conveyor 2 and the loading and unloading mechanism.

[0046] An oxygen content display meter 14 and a preheating table controller 22 are also installed on the marble table top 18.

[0047] The working process of the present invention is briefly described as follows:

[0048] 1. In the previous process, the product carrier 20 carrying the product (the silicon chip 43 and the PCB substrate 44 pads are well aligned) flows into 1-loading belt conveyor. When it flows to the material collection position, the loading belt conveyor line blocking block 40 rises. When the product approaches the blocking block, it slowly decelerates and gently stops at the blocking position.

[0049] 2. The loading mechanism with the loading suction cup moves to the loading position of the conveyor belt line. The vacuum of the suction cup is turned on to suck up the product carrier 20. The loading and handling Z-axis module 6 slowly rises with the suction cup and the product. As the loading and handling Y-axis module 5 and the loading and unloading and handling X-axis module 9 move in coordination, the suction cup transports the product carrier 20 to the top of the preheating table 21 in the waiting area. The loading and handling Z-axis module 6 slowly lowers the product carrier 20 to the preheating table 21 in the waiting area. The temperature of the preheating table is set to 90°C.

[0050] 3. Loop through steps 1-2, place two product carriers 20 on the preheating table 21 in the waiting area, after the first carrier is preheated for 1 minute, the loading suction cup sucks up the carrier, and the loading mechanism with the loading suction cup moves the carrier to the nitrogen-filled cavity fixture 19 where the welding Y-axis linear module 4 is in the loading position, the suction cup puts down the product carrier 20, the fixture Y-axis module and the 27-cover lifting electric cylinder respectively drive the nitrogen-sealed fixture cover to slide forward and press down, the nitrogen-sealed fixture cover is pressed down to seal the nitrogen-filled cavity fixture 19, and at the same time, it moves to the material taking position of the 1-loading belt conveyor, sucks up the third product carrier 20 and moves it to the preheating table 21 in the waiting area.

[0051] 4. The nitrogen solenoid valve is opened, and nitrogen is flushed into the nitrogen-filled cavity fixture 19 through the cavity nitrogen inlet 37. When the oxygen content probe 15 installed in the nitrogen-filled cavity fixture 19 detects that the concentration of nitrogen reaches more than 99%, the nitrogen solenoid valve is closed to stop charging, and the welding heating table 25 starts working and heats up to 100°C.

[0052] 5. Weld the Y-axis linear module 4 to move the nitrogen-sealed cavity fixture to the position to be measured directly below the altimeter 38. By welding the X-axis linear module 3 and the Y-axis linear module 4, the height measurement is moved to the three height measurement points of the product to measure and collect height values. Then the upper computer software will automatically process the three height measurement data and feed back the surface compensation values ​​to the α-axis motor module 31 and the β-axis motor module 33 for linkage to ensure the leveling of the fixture platform.

[0053] 6. Weld the X-axis linear module 3 to move the β-axis motor module 33 to the top of the silicon chip in the product carrier 20, and perform visual positioning through the barium chloride glass fixture cover 26. Weld the X-axis linear module 3 to move the CCD module 11 to the top of the remaining 5 silicon chips in turn, and perform visual positioning in turn.

[0054] 7. The welding X-axis linear module 3 moves the variable spot welding head 10 to the top of the silicon chip in the product carrier 20 according to the precise position of the positioned silicon chip. Then the variable spot welding head 10 emits a laser beam 42 and focuses it on the silicon chip 43 through the upper cover plate 26 of the fixture. The light emission time is 10s to complete the single-chip welding. The welding X-axis linear module 3 moves the variable spot welding head 10 to the top of the silicon chips in the remaining 5 product carriers 20 in turn according to the precise position of the positioned silicon chip to complete the welding of 6 products.

[0055] 8. The laser temperature curve is: ①170℃, 4000ms, slope 90%; ②280℃, 3000ms; ③150℃, 3000ms, slope 80%.

[0056] 9. During the bonding process, the infrared thermal imaging probe 12 will automatically record the temperature changes of the silicon chip and its surroundings through the jig cover 26 for tracing back abnormal analysis.

[0057] 10. The welding Y-axis linear module 4 moves the nitrogen-sealed cavity fixture to the material removal position, the upper cover of the nitrogen-sealed fixture rises through the cover lifting electric cylinder 27, and is translated through the fixture Y-axis module 36, and the nitrogen-filled cavity fixture 19 is in an open state.

[0058] 11. The loading mechanism with the unloading suction cup moves to the position just above the nitrogen-filled cavity fixture 19, and the loading and unloading X-axis module 9 slowly descends to the surface of the product carrier 20 with the suction cup. The suction cup vacuum is turned on to suck up the product carrier 20, and the loading and unloading X-axis module 9 slowly rises with the suction cup and the product. As the unloading Y-axis module 7 and the loading and unloading X-axis module 9 move in coordination, the suction cup transports the product carrier 20 to the cooling unloading table 23.

[0059] 12. When the system determines that there is no product on the unloading belt conveyor 2, the product carrier 20 on the cooling unloading table 23 can be unloaded to the unloading belt conveyor 2 for transmission to the next station for processing; when the system determines that there is a product on the unloading belt conveyor 2, the product carrier 20 on the cooling unloading table 23 is in a waiting state. The cooling unloading table 23 can buffer up to two product carriers 20.

[0060] The present invention solves the problem that the chip packaging unit and the substrate warp and deform inconsistently during the reflow soldering process, the pins of the chip packaging unit and the corresponding positions of the pads on the substrate are offset, which easily leads to the variation of the metallurgical bonding morphology between the chip bumps and the substrate pads, resulting in risky products.

[0061] The present invention adopts laser as a heat source, replacing the traditional reflow soldering process, and can solve the problem of uneven heat caused by temperature difference during silicon chip bonding, thereby causing variation in metallurgical bonding morphology.

[0062] The fully automatic loading process and the high degree of automation of the entire welding process can greatly improve the processing efficiency, processing accuracy and yield rate of chip bonding. Compared with the traditional reflow soldering method, it can greatly improve the quality of bonding and ensure that there are no problems such as false solder joints and cold solder joints. The efficiency of the entire laser bonding equipment is UPH ≥ 300.

[0063] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implying the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0064] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A silicon photonic chip laser bonding device, comprising a marble table (18), on which a loading belt conveyor (1), a unloading belt conveyor (2), a welding mechanism and a loading and unloading mechanism are arranged; characterized in that: A loading belt conveyor (1) and a unloading belt conveyor (2) are sequentially installed from left to right on the front end of the marble table (18); a welding mechanism is arranged at the middle of the rear end of the marble table (18); a jig platform is arranged on the marble table (18) in front of the welding mechanism; and a loading and unloading mechanism is arranged above the jig platform; The loading belt conveyor (1) and the unloading belt conveyor (2) are respectively used for loading and unloading the product carrier (20); the loading and unloading mechanism is used for transporting the product carrier (20) on the loading belt conveyor (1) to the jig platform and for transporting the processed product carrier (20) from the jig platform to the unloading belt conveyor (2); and the welding mechanism is used for welding the product carrier (20) placed on the jig platform.

2. The silicon photonic chip laser bonding device according to claim 1, characterized in that: The welding mechanism comprises a welding gantry (24) mounted on a marble table (18); a welding X-axis linear module (3) and a welding Z-axis module (13) mounted on the welding gantry (24) respectively drive a welding moving plate to move in the X-axis and Z-axis directions; and a variable spot welding head (10) is mounted on the welding moving plate.

3. The silicon photonic chip laser bonding device according to claim 2, characterized in that: A CCD module (11), an infrared thermal imaging probe (12) and a height meter (38) are also installed on the welding motion plate on one side of the variable spot welding head (10).

4. The silicon photonic chip laser bonding device according to claim 1, characterized in that: The jig platform comprises a welding Y-axis linear module (4) mounted on a marble table (18); the welding Y-axis linear module (4) drives the jig module above to move in the Y-axis direction through a jig platform module fixing plate (34); the jig module comprises a multi-directional swing module mounted on the jig platform module fixing plate (34); a jig mounting base plate (39) is mounted on the multi-directional swing module; a nitrogen-filled cavity jig (19) is mounted on the jig mounting base plate (39); a jig upper cover plate (26) is arranged above the nitrogen-filled cavity jig (19); the jig upper cover plate (26) moves in the Y-axis direction under the drive of the jig Y-axis module (36) and the slide rail (30) mounted on the jig mounting base plate (39); and the jig upper cover plate (26) moves in the Z-axis direction under the drive of a cover plate lifting electric cylinder (27).

5. The silicon photonic chip laser bonding device according to claim 4, characterized in that: The multi-directional swing module comprises an α-axis motor module (31), a θ-axis motor module (32) and a β-axis motor module (33).

6. The silicon photonic chip laser bonding device according to claim 1, characterized in that: A welding heating platform (25) is installed on a fixture mounting base plate (39) at the bottom of the nitrogen-filled cavity fixture (19), and an oxygen content probe (15), a laser power meter (28) mounted on a power meter fixing plate (35), and a cavity nitrogen inlet (37) are also installed on the fixture mounting base plate (39).

7. The silicon photonic chip laser bonding device according to claim 1, characterized in that: The loading and unloading mechanism comprises a loading and unloading mechanism gantry (29) installed on a marble table (18); a loading and unloading X-axis module (9) installed on the loading and unloading mechanism gantry (29) drives the loading and unloading components and the unloading components on the left and right sides to move in the X-axis direction respectively; the loading component comprises a loading and unloading Y-axis module (5), a loading and unloading Z-axis module (6) and a material taking suction cup (16); the unloading component comprises a unloading Y-axis module (7), a unloading Z-axis module (8) and a unloading suction cup (17).

8. The silicon photonic chip laser bonding device according to claim 1, characterized in that: A material waiting area preheating table (21) is installed on the marble table top (18) between the loading belt conveyor (1) and the loading and unloading mechanism, and a cooling unloading table (23) is installed on the marble table top (18) between the unloading belt conveyor (2) and the loading and unloading mechanism.

9. The silicon photonic chip laser bonding device according to claim 1, characterized in that: An oxygen content display meter (14) and a preheating table controller (22) are also installed on the marble table top (18).

10. The silicon photonic chip laser bonding device according to claim 1, characterized in that: A loading conveyor belt line blocking block (40) is installed on the loading conveyor belt (1), and a unloading conveyor belt line blocking block (41) is installed on the unloading conveyor belt (2).

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