JPH0543957B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a furnace temperature monitoring device for a reflow furnace in which an object to be heated is conveyed into the furnace by a conveyor to perform adhesive curing, soldering, etc. .

[Background Art] Generally, reflow, in which an object to be heated is conveyed into a furnace on a conveyor to harden adhesive, solder, etc., is operated under preset control conditions.
The object to be heated is heated in a predetermined heating pattern. For example, when soldering components mounted on a printed circuit board using cream solder, the heating method is determined based on the area, thickness, material of the printed circuit board, the number or area of components, the melting point of the solder, etc. The control and conveyance speed of the conveyor are controlled so that the heating is performed in a predetermined heating pattern. By the way, when setting control conditions to obtain a predetermined heating pattern, it is necessary to actually measure and determine the temperature inside the reflow oven and monitor whether or not the predetermined heating pattern is obtained. . Conventionally, an in-furnace temperature monitoring device used in such a case, as shown in FIG. The measuring unit 20 is configured to measure the temperature of the area and store the measured data in a storage means, and the monitor unit 21 reads out the measured data from the storage means in the measuring unit 20 and prints it out (or displays it). was. The heating means is formed by a plurality of heaters H arranged vertically along the conveyance direction of the conveyor 2, an ultraviolet lamp UV is provided in the front stage of the heating means, and a halogen lamp HL is provided in the rear stage of the heating means. There is. However, in such a conventional example, after the circuit section 20b of the conventional unit 20 is housed in the heat insulating case 20a and passed through the reflow oven A, the measuring unit 20 is opened as shown in FIG. 4b. It is necessary to take out the circuit section 20b from the heat insulating case 20a, connect it to the monitor unit 21, read out the data, and print it out (or display it).
There was a problem in that the monitoring work was troublesome, and the temperature inside the reflow oven could not be monitored in real time, resulting in a long time required for monitoring (waiting time).

[Objective of the Invention] The present invention has been made in view of the above points, and its purpose is to simplify the monitoring work of the furnace temperature, to be able to monitor the furnace temperature in real time, Moreover, it is an object of the present invention to provide a furnace temperature monitoring device that can weaken the radio waves transmitted from the data transmitter and prevent radio wave interference to other electronic devices.

[Disclosure of the Invention] (Structure) The present invention is designed to measure the temperature of a main part of an object that is conveyed into a reflow oven along with an object to be heated, and transmits a radio wave with a carrier wave modulated by the measurement data to an insulated case. a data transmitter that transmits data from a transmitting antenna protruding from the furnace; a receiving antenna that is installed above the conveyor in the furnace along the conveying direction and receives the radio waves; and a data signal that amplifies and demodulates the output of the receiving antenna. By forming it with an output data receiver, monitoring the furnace temperature is easy and the furnace temperature can be monitored in real time, and the radio waves emitted from the data transmitter can be weakened. An object of the present invention is to provide an in-furnace temperature monitoring device that can reduce radio wave interference to other electronic devices.

(Embodiment) Figures 1 to 3 show an embodiment of the present invention, in which the object to be heated 1 is transported together with the object to be heated 1 on a conveyor 2 into a reflow oven A, and the temperature of the main part of the object to be heated 1 is measured. At the same time, a data transmitter 3 transmits a radio wave (150MHz F2D) with a carrier wave modulated by the measurement data from a transmitting antenna 5 protruding from the heat insulating case 4, and a data transmitter 3 is installed above the conveyor 2 in the furnace along the conveyance direction. A receiving antenna 6 is installed and receives the radio waves.
and a data receiver 7 which amplifies and demodulates the output of the receiving antenna 6 and outputs measurement data. Here, in the embodiment, the data transmitter 3:
The measurement data (0 to 300°C, resolution 1°C, sampling time 0.2sec) of the main part temperature of the heated object 1 detected using thermocouples TC ₁ to TC ₄ is sent to the transmitting antenna 5.
The data transmitter 3 is adapted to be driven by a battery housed in a heat insulating case 4. The heat insulating case 4 that houses the circuit section and batteries of the data transmitter 3 is formed of a heat insulating plate with a stainless steel surface and Bakelite on the back to avoid temperature rise caused by the heating means. , the transmitting antenna 5 is exposed and thermocouples TC ₁ to _{TC 4} are led out. Thermocouple TC ₁ ~
The drawer portions of the TC ₄ and the transmitting antenna 5 from the heat insulating case 4 have an insulating and heat-insulating drawer structure sandwiched by mica. On the other hand, the receiving antenna 6 stretched inside the furnace is supported by a heat-resistant insulator with a heat-resistant temperature of 1300°C. Furthermore, the measurement data output from the data receiver 7 is processed by a data processing circuit, printed out by a printer, and displayed on a CRT display device.

The operation of the embodiment will be specifically explained below. Currently, the data transmitter 3 is placed on a printed circuit board, which is the object to be heated 1, and passes through the furnace.While passing through the furnace, the data transmitter 3 prints data at fixed time intervals (0.2 seconds). The temperature at four locations on the board is measured by thermocouples TC ₁ to TC ₄ , and the measurement data obtained by A/D converting the measurement signal is transmitted from the transmitting antenna 5 by radio waves using a carrier wave of a predetermined frequency (150 MHz). It is becoming more and more common. This radio wave is received by a receiving antenna 6 placed above the conveyor 2, and is amplified and demodulated by a data receiver 7 to obtain measurement data. This measurement data is processed by a data processing circuit, and the heating pattern is displayed in real time on a printout or CRT display. As described above, in the present invention, the heating pattern can be measured simply by transporting the data transmitter on the conveyor 2 and passing it through the furnace, making it easy to monitor the temperature inside the furnace. It is now possible to monitor the furnace temperature in real time. In addition, since the receiving antenna 6 is stretched along the conveyance path of the heated object 1, the radio waves emitted from the transmitting antenna 5 are weak radio waves (at a distance of 3 m) that do not cause radio interference to other electronic devices. Data transmission between the data transmitter 3 and the data receiver 7 can be performed reliably even if the electric field strength at a point is 500 μV/m or less.

[Effects of the Invention] As described above, the present invention measures the temperature of the main part of the object that is conveyed to the reflow oven together with the object to be heated, and also insulates the radio wave whose carrier wave is modulated using the measurement data. A data transmitter transmits data from a transmitting antenna protruding from the case, a receiving antenna extends above the conveyor in the furnace along the conveyance direction and receives the radio waves, and a data signal is generated by amplifying and demodulating the output of the receiving antenna. and an output data receiver, and the heating pattern can be measured simply by transporting the data transmitter on conveyor 2 and passing it through the furnace, making it easy to monitor the temperature inside the furnace. The temperature inside the furnace can be monitored in real time, and since the receiving antenna is installed along the conveyance path, the radio waves emitted from the data transmitter can be weakened, making it difficult for other electronic devices to This has the effect of reducing radio wave interference.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, FIG. 2 is a configuration diagram of the main parts of the same as above, FIG. FIG. b is an explanatory diagram of the same operation as above. A is a reflow oven, 1 is an object to be heated, 2 is a conveyor, 3 is a data transmitter, 4 is a heat insulating case, 5 is a transmitting antenna, 6 is a receiving antenna, and 7 is a data receiver.

Claims (1)

[Claims] 1 Data that is transported along with an object to be heated on a conveyor into a reflow oven, measures the temperature of the main part of the object, and transmits radio waves with a carrier wave modulated by the measurement data from a transmitting antenna protruding from a heat insulating case. The temperature inside the furnace is comprised of a transmitter, a receiving antenna that is installed above the conveyor in the furnace along the conveyance direction and receives the radio waves, and a data receiver that amplifies and demodulates the output of the receiving antenna and outputs a data signal. Monitor device.