Dynamic over-temperature alarm oven

Abstract

The invention discloses a dynamic over-temperature alarm oven. A temperature sensor and a switch panel for controlling a heating power supply and a cooling fan are inserted into one wall surface of the oven; in addition, a controller with a built-in temperature-time corresponding relation control program is arranged, and an over-temperature alarm device is arranged on the top of the drying oven. The temperature sensor can receive temperature change signals in the drying oven and transmit the signals to the controller, and the time displayer is connected with the controller and can transmit heating time signals to the controller. The controller judges whether to send an alarm signal or not according to a built-in time-temperature corresponding relation Temp = f (t) and an allowable error range, and has two parameter real-time control modes at the same time. The time and temperature curve is displayed in real time, the baking process is regulated in real time, the whole baking process can be monitored, and the material baking quality is improved.

Description

Technical Field

[0001] The invention relates to a drying oven and an alarm setting technology thereof. Background Art

[0002] Oven, also known as baking machine, is a kind of drying equipment. It is widely used in precision baking, drying and shaping processing of optoelectronics, electronics, motors, communications, electroplating, plastics, mechanical equipment, etc.

[0003] Working principle of the oven: the temperature is controlled by connecting the digital display instrument with the temperature sensor, and the hot air circulation air supply method is adopted; the air source is the air supply motor driving the wind wheel through the electric heater, and the hot air is sent to the air duct and then enters the oven working room, and the used air is sucked into the air duct as the air source for re-circulation heating, which can effectively improve the temperature uniformity.

[0004] Operation process: Turn on the power switch, turn off the air switch, press the start button (fan starts), press the heating start button, the ammeter works, set the temperature, set the constant temperature time, after reaching the set temperature, cut off the heating power supply, the fan continues to work and stops working after reaching the set shutdown time.

[0005] The traditional reasons for oven alarms are: partly because the time has not reached the set value, and partly because the internal temperature has not reached the set temperature or is too high.

[0006] The invention with application publication number: CN103721771A discloses an alarm oven, including an oven body and a plurality of metal mesh partitions arranged inside the oven body, at least one temperature sensor is arranged inside the oven body, a timer, an alarm and a control panel are arranged on the oven body, the temperature sensor, the timer and the alarm are all connected to the control panel, and an epoxy resin plate is arranged on each metal mesh partition. After adopting the above structure, the temperature sensor can detect the temperature inside the oven body, when the temperature rises to the set temperature, the timer starts timing, when the time recorded by the timer reaches the set insulation time, the alarm will automatically alarm, reminding the tester to start the test. The alarm is a one-time alarm after reaching the high temperature point. Summary of the invention

[0007] Purpose of the invention: It overcomes the disadvantage that traditional ovens can only alarm once when the time or temperature reaches a certain point, and cannot continuously monitor and alarm.

[0008] Provided is a dynamic over-temperature alarm oven which can timely alarm and adjust the temperature according to the linear requirements of different temperatures at different times.

[0009] Technical solution: The present invention provides a dynamic over-temperature alarm oven, which has an oven furnace for baking (or heating) materials and an oven door (the oven door is opened and closed to take materials into and out of the oven furnace). A temperature sensor is inserted into one wall of the oven, and the oven is equipped with a switch panel for controlling the heating power supply (starting and stopping the heating power supply and the cooling fan), and the front of the oven has an observation hole; a time display (displaying the baking time value) or a temperature display (displaying the baking temperature value) is also set on the front or one side of the oven. One side of the oven may have a cover plate that is convenient for circuit assembly and maintenance.

[0010] There is also a controller (with a built-in temperature-time correspondence control program, which is compiled according to the requirements of different baking materials). The controller dynamically determines whether the temperature at a certain time point is over-temperature based on the built-in time-temperature correspondence control program and the allowable error range; an over-temperature alarm device is arranged on the top of the oven, and the controller can control the over-temperature alarm device to display the temperature-time change curve, and can send out an alarm signal when the temperature exceeds the limit at that time point.

[0011] An over-temperature alarm device is installed on the top of the oven. The temperature sensor can receive the temperature signal in the oven and transmit it to the controller; the temperature sensor is connected to the temperature display to display the temperature of the material in the oven in real time, and the time display can display the baking time value and transmit the baking time signal to the controller.

[0012] The baking time signal and the material temperature signal are transmitted to the controller together. The controller makes a judgment based on the built-in time-temperature correspondence Temp=f(t) control program (where Temp represents the temperature function and t represents the time parameter) and the allowable error range (for example, plus or minus 3°C).

[0013] When the temperature exceeds the corresponding value and the allowable error, the controller controls the connected over-temperature alarm device to send an alarm signal immediately. Preferably, the over-temperature alarm device can display a temperature-time function change curve.

[0014] In addition, the controller also has the following two instant control modes: 1) When the temperature at a certain point in time does not exceed the allowable error: ① When the temperature corresponding to a certain point in time during the baking process exceeds the preset value Temp=f(t) in the control program, the over-temperature alarm device is controlled to send out an alarm signal; when the high temperature difference does not exceed the allowable error range, the controller synchronously controls the heating power supply to suspend heating, and the cooling fan starts to blow out cold air for cooling. When the temperature drops to the preset value, the subsequent baking program continues.

[0015] ② When the temperature corresponding to a certain point in time during the baking process is lower than the preset value Temp=f(t) in the control program, the over-temperature alarm device is controlled to send out an alarm signal; when the low temperature difference does not exceed the allowable error range, the controller synchronously controls the heating power supply to continue heating, and the cooling fan is suspended. When the temperature rises to the preset value, the subsequent baking program continues.

[0016] 2) When the temperature at a certain point in time exceeds the allowable error: Stop baking immediately and notify the personnel to repair the oven. After the repair is completed, restart the new baking program.

[0017] Beneficial effects: The present invention can measure and display temperature values ​​at different time points.

[0018] When the temperature exceeds the allowable error at a certain value, an alarm is issued to remind the operator to perform maintenance.

[0019] When the temperature does not exceed the allowable error range near a certain value point, the controller can automatically adjust the heating to increase the temperature or the blowing to cool down the temperature so that the subsequent baking process can continue.

[0020] It not only displays the time-temperature curve in real time, but also regulates the baking process in real time, so that the whole baking process of the material can be monitored and the quality of the baking material is improved.

[0021] Moreover, the number of downtimes for maintenance is small and the baking efficiency is high.

[0022] It is convenient to take and place materials and observe materials, and it is convenient to shut down the machine to repair circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a three-dimensional structural schematic diagram of the present invention; Figure 2 yes Figure 1 Schematic diagram of the other direction; Figure 1 , Figure 2 Middle: 1- oven door; 2- oven furnace; 3- observation hole; 4- temperature display; 5- time display; 6- switch panel; 7- over-temperature alarm device.

[0024] Figure 3 This is a schematic diagram of a temperature-time variation curve of the present invention when used in baking: 1) Preheating stage: During this stage, the device should be heated up gradually to release internal stress, while controlling the heating rate to avoid thermal shock.

[0025] 2) Constant temperature stage: During this stage, the temperature inside and outside the device should be uniform, and the solvent should be driven away to avoid tin splashing.

[0026] 3) Peak temperature intense heating stage: The temperature of the device rises rapidly to the peak value. The peak temperature and holding time should be strictly controlled to prevent overheating.

[0027] 4) Cooling stage: The temperature of the device gradually decreases. The appropriate cooling rate helps to reduce internal stress and improve product reliability. DETAILED DESCRIPTION

[0028] Embodiment 1: like Figure 1 The dynamic over-temperature alarm oven shown has an oven furnace 2 for baking materials and an oven door 1. A temperature sensor is inserted into the oven furnace 2 on one wall of the oven. A switch panel 6 for controlling the heating power supply and the cooling fan is arranged on the front of the oven. A controller is provided. The baking time signal and the material temperature signal are transmitted to the controller together. An over-temperature alarm device 7 is arranged on the top of the oven. The controller makes a judgment based on the built-in time-temperature correspondence and the control program of the allowable error range. The controller can control the display screen of the over-temperature alarm device 7 to display the temperature-time change curve, and can send out a beeping alarm signal when the temperature is over-temperature.

[0029] When a lead frame chip plastic package is baked in the oven of the present invention, its temperature-time variation function is Temp=f(t), and the temperature-time variation curve is as follows: Figure 3 Different time points correspond to different temperature requirements.

[0030] The specific baking temperature-time of lead frame epoxy resin plastic encapsulation components are as follows: Preheating rate Time required to reach 150℃ Constant temperature insulation 140-210℃ Peak temperature 140℃ 165℃ Cooling phase 2-3℃ / sec <90 seconds 60-100 seconds 170-180℃ 30-60 seconds 10-20 seconds <4℃ / sec .

[0031] When the temperature at a certain time point exceeds or is lower than the temperature calculated by the function by more than 3° C., the over-temperature alarm device 7 sends out an alarm signal to stop the baking process.

[0032] When the temperature at a certain point in time has an error of no more than 3°C with the temperature calculated by the function, the subsequent baking procedure is continued by selecting and using the heating power supply and the cooling fan to maintain the baking temperature normal throughout the entire time period in order to obtain a qualified lead frame chip plastic package product.

[0033] Embodiment 2: The oven of the first embodiment is also provided with a time display 5 on the front thereof, which can display the baking time, and a temperature display 4, which can display the instantaneous temperature value. If the over-temperature alarm device 7 fails or is suspended, the baking process can be monitored by manually observing the time display 5 and the temperature display 4.

[0034] There is also a transparent glass observation hole 3 on the front of the oven, which is convenient for observing the state of the material being baked. When the material state is abnormal, the power supply and the fan can also be turned on and off through the switch panel 6.

Claims

1. A dynamic over-temperature alarm oven, comprising an oven furnace (2) for baking materials and an oven door (1), a temperature sensor for measuring the temperature of the materials inserted into a wall of the oven, and a switch panel (6) for controlling a heating power supply and a cooling fan, characterized in that: There is also a controller with a built-in control program for the temperature-time correspondence, and a baking time signal and a material temperature signal are transmitted to the controller together; the controller dynamically determines whether the temperature at a certain time point is over-temperature based on the built-in control program for the time-temperature correspondence and an allowable error range; an over-temperature alarm device (7) is arranged on the top of the oven, and the controller can control the over-temperature alarm device (7) to display a temperature-time change curve, and can send out an alarm signal when the temperature is over-temperature at that time point.

2. The dynamic over-temperature alarm oven according to claim 1, characterized in that: The controller has the following two immediate control modes: 1) When the temperature at a certain time point exceeds the preset value Temp=f(t) in the control program and does not exceed the allowable error range, the baking program continues: ① When the temperature corresponding to a certain time point in the baking process is higher than the preset value Temp=f(t) in the control program, but the difference does not exceed the allowable error range, the controller controls the heating power supply to suspend heating, and the cooling fan starts to blow out cold air for cooling; When the temperature drops to the preset value, continue the subsequent baking process; ② When the temperature at a certain time point in the baking process is lower than the preset value Temp=f(t) in the control program, but the difference does not exceed the allowable error range, the controller controls the heating power supply to continue heating and the cooling fan to stop starting; when the temperature rises to the preset value, the subsequent baking program continues; 2) When the temperature at a certain time point exceeds the preset value Temp=f(t) and the allowable error range, the baking program is stopped directly.

3. The dynamic over-temperature alarm oven according to claim 2, characterized in that: The allowable error is plus or minus 3°C.

4. The dynamic over-temperature alarm oven according to claim 1, 2 or 3, characterized in that: A time display (5) and a temperature display (4) are also provided on the front or one side of the oven.

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