A circuit board pad solder paste rheological maintenance device

Abstract

This utility model discloses a circuit board solder paste rheological maintenance device, which is installed on a conveying device between a solder paste printer and a pick-and-place machine. It includes: a conveying track for transporting circuit boards with solder paste already printed; a movable temperature control device installed on the conveying track; a synchronous drive mechanism connected to the movable temperature control device and driving it to move synchronously with the circuit board along the conveying direction; and a temperature control execution unit integrated inside the movable temperature control device. During synchronous movement, the movable temperature control device continuously applies temperature regulation to the solder pad area of ​​the circuit board through its temperature control working surface. This utility model solves the problem of solder paste rheological degradation and improves pick-and-place quality by continuously adjusting the temperature of the circuit board during transport using a dynamic following temperature control device.

Description

Technical Field

[0001] This utility model belongs to the field of circuit board technology, and in particular relates to a device for maintaining the rheological properties of solder paste on circuit board pads. Background Technology

[0002] After solder paste printing, the circuit board needs to be conveyed to the pick-and-place machine via a conveyor. During this process, the solder paste on the pads is directly exposed to the working environment. When the ambient temperature is too high, the viscosity of the solder paste decreases, causing increased fluidity and resulting in unstable pin insertion, tilting, or tipping during component placement. When the temperature is too low, the solder paste hardens, making pin insertion difficult. Current technology directly conveys the circuit board from the printer to the pick-and-place machine, lacking temperature control measures during the conveying process. Uncontrollable ambient temperature changes lead to an increased defect rate. Although some technologies use preheating at a fixed station, this cannot cover the entire moving conveyor process and has a lag in response. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, this utility model provides a circuit board pad solder paste rheological maintenance device, which continuously adjusts the temperature of the circuit board during transportation through a dynamic following constant temperature device, so as to solve the problem of solder paste rheological degradation and improve the placement quality.

[0004] Technical solution: To achieve the above objectives, this utility model provides a circuit board pad solder paste rheological maintenance device, which is installed on a conveying device between a solder paste printer and a pick-and-place machine, comprising:

[0005] Conveyor rails are used to transport circuit boards that have already had solder paste printed.

[0006] A portable temperature control device is installed on the conveyor track;

[0007] A synchronous drive mechanism is connected to a movable temperature control device and drives it to move synchronously with the circuit board along the conveying direction.

[0008] The temperature control actuator is integrated inside the portable temperature control device;

[0009] During synchronous movement, the movable constant temperature device continuously applies temperature regulation to the solder pad area of ​​the circuit board through its temperature control working surface.

[0010] Furthermore, the movable constant temperature device includes a heating layer and a cooling layer stacked sequentially from top to bottom, both of which are independently temperature-controlled and their working surfaces face the conveyor track.

[0011] Furthermore, a perforated heat-conducting plate is fixed to the bottom of the cooling layer, and a temperature sensor array is embedded in the perforated heat-conducting plate; the perforated holes of the perforated heat-conducting plate are arranged in a matrix, and the probes of the temperature sensor array pass through the perforated holes and face the conveying track, and the ends of the probes have a small gap with the circuit board.

[0012] Furthermore, an insulating layer is provided between the heating layer and the cooling layer.

[0013] Furthermore, the movable constant temperature device also includes a heat insulation cover that is entirely covered by the outside, and the heat insulation cover has openings at both ends for the conveying track; a strip-shaped temperature control window is opened at the bottom of the heat insulation cover, and a guide fin is provided on the inner side of the strip-shaped temperature control window, and the guide fin can open and close the strip-shaped temperature control window by swinging.

[0014] Furthermore, the guide fins are mounted on the heat insulation cover via a pivot shaft, and a fin drive mechanism for driving the pivot shaft is provided outside the heat insulation cover.

[0015] Furthermore, the synchronous drive mechanism is a linear servo slide module that is parallel to and fixedly connected to the conveying track.

[0016] Furthermore, the temperature control execution unit includes a control circuit board and a power drive module. The control circuit board receives signals from the temperature sensor array and independently regulates the power output of the heating layer and the cooling layer.

[0017] Beneficial effects: This utility model uses a movable constant temperature device to dynamically follow the movement of the circuit board and continuously adjust the temperature, so that the solder paste in the solder pad area of ​​the circuit board is in a stable temperature field throughout the process, avoiding abnormal fluctuations in solder paste viscosity caused by changes in ambient temperature during the transportation process, solving the problem of solder paste rheological deterioration and improving the quality of chip mounting. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is a schematic diagram of a half-section of a portable thermostat. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] like Figure 1 and Figure 2As shown, a circuit board solder paste rheological maintenance device is installed on a conveying device between a solder paste printer (a) and a pick-and-place machine (b). The device includes: a conveying track 1 for transporting a circuit board 5 with solder paste already printed; a movable temperature control device 2 installed on the conveying track 1; a synchronous drive mechanism 3 connected to the movable temperature control device 2 and driving it to move synchronously with the circuit board 5 along the conveying direction; and a temperature control execution unit 4 integrated inside the movable temperature control device 2. During synchronous movement, the movable temperature control device 2 continuously applies temperature regulation to the solder pad area of ​​the circuit board 5 through its temperature control working surface. The movable temperature control device 2 dynamically follows the movement of the circuit board 5 to continuously adjust the temperature, ensuring that the solder paste in the solder pad area of ​​the circuit board 5 remains in a stable temperature field throughout the process. This avoids abnormal fluctuations in solder paste viscosity due to changes in ambient temperature during transport, thus solving the problem of solder paste rheological degradation and improving pick-and-place quality.

[0022] like Figure 2 As shown, the movable constant temperature device 2 includes a heating layer 21 and a cooling layer 22 stacked sequentially from top to bottom. The heating layer 21 uses PTC ceramic sheets, and the cooling layer 22 uses a semiconductor cooling chip assembly. Both are independently temperature-controlled, and their working surfaces face the conveyor rail 1. The vertical integration of heating and cooling functions reduces the lateral size of the equipment. The heating layer 21 radiates heat downwards, and the bottom of the cooling layer 22 is fixed with a perforated heat-conducting plate 23. The cooling layer 22 is in close contact with the perforated heat-conducting plate 23 to achieve rapid cooling, avoiding airflow interference in the traditional side-by-side layout.

[0023] The perforated heat-conducting plate 23 is fitted with a temperature sensor array 24. The perforated holes 231 of the perforated heat-conducting plate 23 are arranged in a matrix. The perforated structure reduces the weight of the heat-conducting plate while achieving a balanced heat distribution. The probes 241 of the temperature sensor array 24 pass through the perforated holes 231 and face the conveying track 1. The end of the probe 241 has a small gap with the circuit board 5, ranging from 0.5 to 2 mm. The probe 241 is directly aligned with the pad area to achieve accurate temperature detection and improve the real-time performance of temperature control.

[0024] The temperature control execution unit 4 includes a control circuit board and a power drive module. The control circuit board receives signals from the temperature sensor array 24 and independently regulates the power output of the heating layer 21 and the cooling layer 22. By providing real-time feedback on the solder pad temperature, it dynamically switches between heating and cooling modes and adjusts the output power to maintain the solder paste within a constant viscosity range.

[0025] It is worth noting that a heat insulation layer 25 is provided between the heating layer 21 and the cooling layer 22. The heat insulation layer 25 physically isolates the ineffective heat exchange between the hot and cold layers, prevents the heat from the heating layer 21 from weakening the cooling efficiency, and eliminates the risk of condensation caused by the convergence of hot and cold layers.

[0026] The movable constant temperature device 2 also includes an overall heat insulation cover 26, which is provided with openings at both ends for the conveyor track 1. A strip-shaped temperature control window 261 is opened at the bottom of the heat insulation cover 26, and guide fins 262 are provided on the inner side of the strip-shaped temperature control window 261. The guide fins 262 can open and close the strip-shaped temperature control window 261 by swinging. The heat insulation cover 26 isolates the device from external environmental temperature and humidity interference. The guide fins 262 control the opening and closing of the strip-shaped temperature control window 261: during heating, they guide hot air upwards and outwards; during cooling, they introduce cold air to cover the solder pads, achieving controllable heat exchange.

[0027] The airflow guiding fins 262 are rotatably mounted on the heat insulation cover 26 via a swing shaft 263, and a fin drive mechanism 264 for driving the swing shaft 263 is provided outside the heat insulation cover 26. The fin drive mechanism 264 precisely controls the opening and closing angle of the airflow guiding fins, ensuring that a sealing barrier is formed when the window is closed and that airflow is directionally guided when open, thereby enhancing the flexibility of temperature control response. The fin drive mechanism 264 can be a servo motor-driven belt drive mechanism or a servo motor-driven chain drive mechanism.

[0028] like Figure 1 or Figure 2 As shown, the synchronous drive mechanism 3 is a linear servo slide module that is parallel to and fixedly connected to the conveying track 1. The linear servo slide module ensures that the movable constant temperature device 2 and the circuit board 5 move in strict synchronization, avoiding temperature control blind spots caused by displacement deviation.

[0029] The advantages of this invention are as follows: the movable constant temperature device moves synchronously with the circuit board throughout the transport process, ensuring that the temperature-controlled working surface continuously covers the solder pad area and dynamically isolates environmental interference; the structural design of the heating layer and cooling layer stacked in the same direction from top to bottom, combined with the heat insulation layer to block mutual interference between heat and cold, achieves efficient temperature control response; the hollow heat-conducting plate integrates a temperature sensor probe that directly reaches the solder pad area, ensuring accurate temperature monitoring; the heat insulation cover and the swingable guide fins work together to regulate the internal environment, directionally guide airflow to optimize heat exchange, structurally ensuring the stability of solder paste rheology throughout the transport process, completely solving the problem of solder paste rheological degradation caused by ambient temperature, and significantly improving the chip placement yield and component positioning accuracy.

[0030] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A circuit board pad solder paste rheology maintenance device, disposed on a conveyor device between a solder paste printer (a) and a placement machine (b), characterized by: include: Conveyor track (1) for conveying circuit boards (5) that have completed solder paste printing; A movable constant temperature device (2) is installed on the conveyor rail (1); Synchronous drive mechanism (3) is connected to movable constant temperature device (2) and drives it to move synchronously with circuit board (5) along the conveying direction; Temperature control actuator (4) is integrated inside the portable constant temperature device (2); During synchronous movement, the movable constant temperature device (2) continuously applies temperature control to the pad area of ​​the circuit board (5) through its temperature control working surface.

2. The circuit board pad solder paste rheology maintenance device of claim 1, wherein: The movable constant temperature device (2) includes a heating layer (21) and a cooling layer (22) stacked sequentially from top to bottom. The two layers are independently temperature controlled and their working surfaces face the conveyor track (1).

3. The circuit board pad solder paste rheology maintenance device of claim 2, wherein: The bottom of the cooling layer (22) is fixed to a perforated heat-conducting plate (23), on which a temperature sensor array (24) is embedded; the perforated holes (231) of the perforated heat-conducting plate (23) are arranged in a matrix, and the probes (241) of the temperature sensor array (24) pass through the perforated holes (231) and face the conveying track (1), and the end of the probe (241) has a small gap with the circuit board (5).

4. The circuit board pad solder paste rheology maintenance device of claim 3, wherein: A heat insulation layer (25) is provided between the heating layer (21) and the cooling layer (22).

5. The circuit board pad solder paste rheology maintenance device of claim 3, wherein: The movable constant temperature device (2) also includes a heat insulation cover (26) that is completely covered on the outside. The heat insulation cover (26) has openings at both ends for the conveying track (1). A strip-shaped temperature control window (261) is opened at the bottom of the heat insulation cover (26). A guide fin (262) is provided on the inner side of the strip-shaped temperature control window (261). The guide fin (262) can open and close the strip-shaped temperature control window (261) by swinging.

6. The circuit board pad solder paste rheology maintenance device of claim 5, wherein: The guide fins (262) are rotatably mounted on the heat insulation cover (26) via a swing shaft (263), and a fin drive mechanism (264) for driving the swing shaft (263) is provided outside the heat insulation cover (26).

7. The circuit board pad solder paste rheology maintenance device of claim 1, wherein: The synchronous drive mechanism (3) is a linear servo slide module that is parallel to and fixedly connected to the conveying track (1).

8. The circuit board pad solder paste rheology maintenance device of claim 3, wherein: The temperature control execution unit (4) includes a control circuit board and a power drive module. The control circuit board receives signals from the temperature sensor array (24) and independently regulates the power output of the heating layer (21) and the cooling layer (22).

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