Heating device for hot reflux process

Abstract

The utility model relates to the technical field of heating devices, and discloses a heating device for a hot reflux process, the heating device comprises a heating plate, a cooling system and a heating system, the heating plate is internally provided with a temperature sensor, a heating pipe and a cooling pipe, the heating pipe is circularly communicated with the heating system, the cooling pipe is circularly communicated with the cooling system, and the heating system is communicated with the cooling system. The heating system and the cooling system are both electrically connected with the temperature sensor. The temperature of the heating plate can be detected in real time through the temperature sensor and compared with the set temperature, when the set temperature is higher than the detection temperature, the cooling system is started, when the set temperature is lower than the detection temperature, the heating system is started, and when the set temperature is equal to the detection temperature, the current heating and cooling system is kept; therefore, the heating and cooling processes in the backflow process can be effectively controlled, the stress generated in the cooling process is avoided, the depression of the ball top is prevented, and the profile deviation degree of the cooled rubber ball is ensured to be qualified.

Description

Technical Field

[0001] This utility model relates to the field of heating device technology, and in particular to a heating device for a hot reflux process. Background Technology

[0002] Traditional silicon lens hot-melt methods involve placing photoresist pillars, after photolithography and development, on a hot plate (upright or inverted). The pillars melt under heat, and due to surface tension and gravity, the molten photoresist forms a spherical / aspherical curved microlens. The process includes a hot reflow step. Using traditional hot-melt methods for hot reflow, the reflowed photoresist spheres are subjected to stress during cooling, causing a depression / collapse at the apex (the central part of the microlens), resulting in an M-shaped PV (Peak to Valley) curve. For example, patent CN 202410569558.5 discloses a microlens reflow method and system that uses segmented heating and the introduction of a protective gas to reduce the depression at the central position of the microlens apex, thus obtaining a better spherical surface. This patented method can control the heating temperature and time of each segment, but it cannot control the cooling process, i.e., it cannot control the cooling rate and cooling time of the hot reflow system.

[0003] At room temperature, without actively controlling the cooling time, it typically takes about 60 seconds for a silicon wafer to cool from 180°C to room temperature. This results in different cooling rates between the spheres on the wafer and their edges due to the difference in thickness between the sphere top (center) and the edges. As a result of thermal expansion and contraction, the sphere top may show a concave phenomenon (for example, when a molten candle is poured into a beaker, the candle in the center of the beaker will be lower than the one around it). The stress caused by cooling will lead to an increase in the spherical profile deviation (SPD), which will affect the optical performance of the microlens. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a heating device for hot reflow process, which effectively controls the heating and cooling process during hot reflow, avoids stress generated during cooling, prevents spherical dome depression, and ensures that the profile deviation of the rubber ball is qualified after cooling.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A heating device for a hot reflux process includes a heating plate, a cooling system, and a heating system. The heating plate is equipped with a temperature sensor, a heating tube, and a cooling tube. The heating tube is circulatedly connected to the heating system, and the cooling tube is circulatedly connected to the cooling system. Both the heating system and the cooling system are electrically connected to the temperature sensor.

[0007] Preferably, the temperature sensor is located on the upper part of the heating plate, the heating tube and the cooling tube are located on the lower part of the heating plate, and an auxiliary heating device is also provided in the middle of the heating plate, the auxiliary heating device being electrically connected to the temperature sensor.

[0008] Preferably, the device includes a controller, and both the temperature sensor and the auxiliary heating device are electrically connected to the controller.

[0009] Preferably, the heating plate has a rectangular cross-section, and five temperature sensors are respectively disposed at the four corners and the center of the heating plate.

[0010] Preferably, the bottom of the heating plate is provided with a heat insulation layer.

[0011] Preferably, the heating tube is U-shaped, serpentine, or wavy.

[0012] Preferably, the cooling pipe is U-shaped, serpentine, or wavy.

[0013] Preferably, the heating plate is made of graphene, metal, or high thermal conductivity ceramic.

[0014] Preferably, the flatness of each surface of the heating plate is less than 0.01 mm.

[0015] The heating device for hot reflow process according to this utility model has the following advantages compared with the prior art: By setting a temperature sensor, a heating tube, and a cooling tube inside the heating plate, with the heating tube circulating in connection with the heating system and the cooling tube circulating in connection with the cooling system, and both the heating system and the cooling system being electrically connected to the temperature sensor, the temperature of the heating plate can be detected in real time by the temperature sensor and compared with the set temperature. When the set temperature is higher than the detected temperature, the cooling system is activated; when the set temperature is lower than the detected temperature, the heating system is activated; when the set temperature is equal to the detected temperature, the current heating and cooling systems are maintained. This effectively controls the heating and cooling process during reflow, avoids stress generated during cooling, prevents spherical dome depression, and ensures that the profile deviation of the cooled rubber ball is qualified. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the heating device for the hot reflux process of this utility model.

[0017] Figure 2 This is a cross-sectional view of the heating plate of this utility model.

[0018] The components are: 1-Heating plate, 2-Cooling system, 3-Heating system, 4-Temperature sensor, 5-Heating tube, 6-Cooling tube, 7-Auxiliary heating device, 8-Insulation layer, 9-Controller. Detailed Implementation

[0019] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0020] like Figure 1-2 As shown, a preferred embodiment of the present invention provides a heating device for a hot reflux process, comprising a heating plate 1, a cooling system 2, and a heating system 3. The heating plate 1 is made of a high thermal conductivity material, such as graphene, metal, or a high thermal conductivity ceramic material, and its surface needs to have good flatness, requiring a flatness of less than 0.01 mm. The heating plate 1 internally houses a temperature sensor 4, a heating tube 5, and a cooling tube 6. The heating tube 5 is circulatedly connected to the heating system 3, and the cooling tube 6 is circulatedly connected to the cooling system 2. Both the heating system 3 and the cooling system 2 are electrically connected to the temperature sensor 4. The heating system 3 mainly heats the heating medium through heating elements and then uses a circulating pump to transport the heated medium to the heating tube 5 for further heating. The cooling system 2 is mainly a cooling tank, using a circulating pump to transport the cooling medium to the cooling tube 6. The heating and cooling media can be oil, high-pressure water, or high-pressure steam. The maximum temperature of the heating / cooling media can reach 400℃.

[0021] The heating device for the hot reflow process based on the above features has a temperature sensor 4, a heating tube 5, and a cooling tube 6 installed inside the heating plate 1. The heating tube 5 is circulatedly connected to the heating system 3, and the cooling tube 6 is circulatedly connected to the cooling system 2. Both the heating system 3 and the cooling system 2 are electrically connected to the temperature sensor 4. Thus, the temperature of the heating plate 1 can be detected in real time by the temperature sensor 4 and compared with the set temperature. When the set temperature is higher than the detected temperature, the cooling system 2 is activated. When the set temperature is lower than the detected temperature, the heating system 3 is activated. When the set temperature is equal to the detected temperature, the current heating and cooling system is maintained. This can effectively control the heating and cooling process during reflow, avoid stress generated during cooling, prevent the ball top from denting, and ensure that the profile deviation of the cooled rubber ball is qualified.

[0022] In this embodiment, the temperature sensor 4 is located on the upper part of the heating plate 1, the heating tube 5 and the cooling tube 6 are located on the lower part of the heating plate 1, and an auxiliary heating device 7 is also provided in the middle of the heating plate 1, that is, the auxiliary heating device 7 is located between the temperature sensor 4 and the heating tube 5. The auxiliary heating device 7 is electrically connected to the temperature sensor 4. The auxiliary heating device 7 can adopt an electric heating method or an electromagnetic heating method. In cooperation with the temperature sensor 4, it is used to rapidly heat up the heating plate in the initial stage of heating, and to achieve precise temperature control of the heating plate 1 in the subsequent heat reflow process.

[0023] Meanwhile, to ensure precise control, the heating device for the hot reflux process also includes a controller 9. The temperature sensor 4 and the auxiliary heating device 7 are both electrically connected to the controller 9. The controller 9 can adjust the flow rate of the heating / cooling medium and the on / off state of the auxiliary heating device 7 in real time to achieve precise control of the temperature of the hot plate 1. The temperature control accuracy can reach ±0.1℃. The control part can control the temperature change curve by inputting multiple temperature segments (maximum input segments of more than 20 segments).

[0024] Furthermore, to further ensure control accuracy, the temperature measured by the temperature sensor 4 must be accurate. Multiple sensors can be installed within the heating plate 1. Specifically, the heating plate 1 has a rectangular cross-section, and five temperature sensors 4 are respectively located at the four corners and the center of the heating plate 1. The temperature of the heating plate 1 can be detected in real time and compared with the set temperature (curve). This allows for independent control of the heating and cooling curves, and adjustments can be made according to process parameters. This eliminates stress generated during the cooling process of the rubber balls in the hot reflow process, preventing ball top depression and minimizing the surface deviation (SPD) of the rubber balls.

[0025] In this embodiment, the bottom of the heating plate 1 is provided with a heat insulation layer 8, which can not only effectively maintain the temperature of the heating plate 1 and reduce its heat loss, but also avoid the influence of ambient temperature on the heating plate 1.

[0026] In this embodiment, to ensure the heating effect of the heating tube 5 on the heating plate 1, the heating tube 5 is U-shaped, serpentine, or wavy, thereby providing a larger contact area between the heating tube 5 and the heating plate 1, improving the heating speed and uniformity. Similarly, the cooling tube 6 is also U-shaped, serpentine, or wavy.

[0027] In summary, this application adds a temperature control system to the heating plate 1, avoiding the shortcoming of traditional heating plates 1 that cannot control the cooling curve (cooling rate, cooling time); this application can control the heating curve and cooling curve independently, and can be adjusted according to process parameters to eliminate the stress generated during the cooling of the rubber balls in the hot reflow process, so as to prevent the ball top from sinking and to make the ball profile deviation (SPD) smaller; this application can also automatically set the heating, cooling and heat preservation, which can be set before hot reflow and automatically controlled during hot reflow.

[0028] The working process of the heating device for the hot reflux process in this application is as follows:

[0029] Step 1: Place the silicon lens wafer that needs to be heated on heating plate 1 (upright or upside down), and adjust the tooling fixture to clamp the wafer.

[0030] Step 2: Input the required heating, cooling, and heat preservation time and temperature into the controller;

[0031] Step 3: Heat, hold, and cool the wafer according to the set curve;

[0032] Step 4: Remove the wafer after completion.

[0033] 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 substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A heating device for a reflow process, characterized by: The heating plate is internally provided with a temperature sensor, a heating pipe and a cooling pipe, the heating pipe is in circulation communication with a heating system, the cooling pipe is in circulation communication with a cooling system, and the heating system and the cooling system are electrically connected with the temperature sensor.

2. The heating apparatus for a reflow process according to claim 1, wherein: The temperature sensor is arranged at the upper part of the heating plate, the heating pipe and the cooling pipe are arranged at the lower part of the heating plate, and the middle part of the heating plate is further provided with an auxiliary heating device which is electrically connected with the temperature sensor.

3. The heating apparatus for a reflow process according to claim 2, wherein: The temperature sensor and the auxiliary heating device are electrically connected with a controller.

4. The heating apparatus for a reflow process according to claim 1, wherein: The cross section of the heating plate is rectangular, the temperature sensor is five, and is arranged at the four corners and the center of the heating plate.

5. The heating apparatus for a reflow process according to claim 1, wherein: The bottom of the heating plate is provided with a heat preservation layer.

6. The heating device for a reflow process according to any one of claims 1 to 5, characterized in that: The heating pipe is U-shaped or serpentine or wave-shaped.

7. The heating device for a reflow process according to any one of claims 1 to 5, characterized in that: The cooling pipe is U-shaped or serpentine or wave-shaped.

8. The heating device for a reflow process according to any one of claims 1 to 5, wherein: The material of the heating plate is graphene or metal or high-thermal-conductivity ceramic.

9. The heating device for a reflow process according to any one of claims 1 to 5, wherein: The flatness of each surface of the heating plate is less than 0.01 mm.

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