Corrosion warning device and work apparatus

Abstract

To provide a corrosion warning device which can secure sufficient preparation time for replacement of substrate components required due to corrosion and a work apparatus equipped with the corrosion warning device.SOLUTION: A corrosion warning device 40 that warns of corrosion of mounted electronic components mounted on a control board 17 caused by corrosive substances includes: a corrosion detection circuit 22 that is configured by installing, on the control board 17, a test part 32 having a metal with lower corrosion resistance to corrosive substances than that of the mounted electronic components; and a determination circuit 23 as a determination unit that determines a level of corrosion of the test part 32 by comparing a transmission signal S1 transmitted to the test part 32 with a reception signal S2 passed through the test part 32 in the corrosion detection circuit 22. A determination result determined by the determination circuit 23 is displayed on a display device 19 as a result display unit.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a corrosion warning device that warns of corrosion caused by a corrosive substance in an electronic component mounted on a circuit board, and a work device equipped with the same. [Background technology]

[0002] A known example of a work device that controls a work unit to perform a predetermined task on a work object is a component mounting device that mounts chip components on a printed circuit board. In such a work device, a control board (control board) that controls the work unit is equipped with numerous electronic components, some of which may corrode depending on the operating environment of the work device. Electronic components containing silver or copper are susceptible to sulfide corrosion, which occurs in high-temperature sulfur-containing atmospheres and causes insulation failure. Early detection and countermeasures for such sulfide corrosion are crucial for the operation of the work device. One known method for early detection of such environmental corrosion involves a corrosion detection circuit that includes a test part containing a metal that is susceptible to corrosion by corrosive substances, constantly applying a voltage to the test part, and monitoring changes in the output voltage from the corrosion detection circuit to detect open circuits due to corrosion of the test part (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6148286 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above-mentioned conventional technology, the progression of corrosion in the control board is only discovered after a break in the circuit board due to corrosion of the test part is detected, which creates the problem that preparations (such as procuring parts) for replacing board components (mounted electronic components or the control board itself) that become necessary due to corrosion may not be made in time.

[0005] Therefore, the present disclosure aims to provide a corrosion warning device that can ensure sufficient preparation time for replacing circuit board components that become necessary due to corrosion, and a work device equipped with this corrosion warning device. [Means for solving the problem]

[0006] The corrosion warning device disclosed herein is a corrosion warning device that warns of corrosion caused by a corrosive substance in an electronic component mounted on a circuit board, and includes a corrosion detection circuit configured by placing a test part on the circuit board, the test part having a metal that has lower corrosion resistance to the corrosive substance than the electronic component; a judgment unit that judges the stage of corrosion of the test part by comparing a transmission signal sent to the test part in the corrosion detection circuit with a received signal received from the test part; and a result display unit that displays the judgment result judged by the judgment unit.

[0007] The working device of the present disclosure includes the corrosion warning device of the present disclosure, and the board is a control board that controls the operation of the working unit. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to ensure sufficient preparation time for replacement of board components that may become necessary due to corrosion. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a simplified configuration diagram of a working device according to an embodiment of the present disclosure; [Figure 2] FIG. 1 is a configuration diagram of a corrosion warning device provided in a work device according to an embodiment of the present disclosure. [Figure 3]1A, 1B, and 1C are diagrams showing an example of a transmission signal and a reception signal transmitted and received by a microcomputer of a corrosion warning device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, with reference to the drawings as appropriate, detailed descriptions will be provided regarding embodiments specifically disclosing the corrosion warning device and work device according to the present disclosure. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of already well-known matters and redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0011] An embodiment of the present disclosure will now be described with reference to the drawings. FIG. 1 is a simplified structural diagram of a working device according to one embodiment of the present disclosure. FIG. 1 shows a component mounting device as a working device 1 equipped with a corrosion warning device according to the present disclosure. In FIG. 1, the working device 1 is a device for mounting chip components BH on a printed circuit board KB. It includes a printed circuit board holder 12 mounted on a base 11 and holding the printed circuit board KB, a parts feeder 13 as a chip component supply unit, and a mounting head 14 as chip component mounting means. The parts feeder 13 is, for example, a tape feeder that supplies components using a tape member that stores a large number of chip components in a single row. The mounting head 14 has a nozzle 14N extending downward, and generates a vacuum suction force at the bottom end of the nozzle 14N to pick up (pick up) the chip components BH supplied by the parts feeder 13. The mounting head 14 is moved horizontally by a head movement mechanism 15, for example, an XY movement mechanism.

[0012] Figure 2 is a configuration diagram of a corrosion warning device provided in a working apparatus according to one embodiment of the present disclosure. Working apparatus 1 is provided with a control unit 16 within base 11. Control unit 16 has a control board 17, which outputs control signals from operation control circuit 21 shown in Figure 2 to control part feeder 13, mounting head 14, and head movement mechanism 15. In other words, control board 17 controls the operation of part feeder 13, mounting head 14, and head movement mechanism 15 as working unit 18 (Figure 2). Control device 16 (control board 17) is connected to display device 19 provided on base 11, and displays necessary information to the operator of working apparatus 1.

[0013] When the working device 1 performs a chip component mounting operation to mount chip components BH on a printed circuit board KB, the control unit 16 (control board 17) controls the parts feeder 13 to supply the chip components BH to a predetermined component supply position, and operates the head moving mechanism 15 to move the mounting head 14 back and forth between the printed circuit board KB held by the printed circuit board holding unit 12 and the parts feeder 13. While moving the mounting head 14 between the printed circuit board KB and the parts feeder 13, the control unit 16 causes the mounting head 14 to pick up chip components BH from the parts feeder 13 and mount the picked-up chip components BH on the printed circuit board KB. In this way, the chip components BH are mounted one after another on the printed circuit board KB.

[0014] In the working device 1 configured as above, the control board 17 that constitutes the control unit 16 is provided with a corrosion detection circuit 22 and a determination circuit 23, as shown in Fig. 2. The corrosion detection circuit 22 has a microcomputer 31 and a test part 32 that serve as a signal transmitting / receiving unit connected by a copper wire pattern, and the microcomputer 31 transmits a transmission signal S1 consisting of a voltage signal to the test part 32, and receives the voltage signal that has passed through the test part 32 as a reception signal S2. The test part 32 is made of a resistor that includes metal.

[0015] Here, the resistors constituting test part 32 have a metal that has lower corrosion resistance to corrosive substances than the electronic components (not shown) that are the targets of corrosion testing and are components of operation control circuit 21 mounted on control board 17. In this embodiment, sulfur-based gases are assumed as the corrosive substance, and the metal of test part 32 is silver.

[0016] The judgment circuit 23 functions as a judgment unit, and judges the stage of corrosion of the test part 32 by comparing the transmission signal S1 sent to the test part 32 in the corrosion detection circuit 22 with the reception signal S2 received from the test part 32. The judgment circuit 23 displays the judgment result on the display device 19 described above.

[0017] As described above, the working device 1 in this embodiment is equipped with a corrosion detection circuit 22 configured by mounting on the control board 17 a test part 32 made of a metal that has lower corrosion resistance to corrosive substances than the mounted electronic components mounted on the control board 17, a judgment circuit 23 as a judgment unit that judges the stage of corrosion of the test part 32 by comparing the transmission signal S1 sent to the test part 32 in the corrosion detection circuit 22 with the reception signal S2 received from the test part 32, and a display device 19 as a result display unit that displays the judgment result judged by the judgment circuit 23. The corrosion detection circuit 22, the judgment circuit 23 and the display device 19 together constitute a corrosion warning device 40 that warns of corrosion of the mounted electronic components mounted on the control board 17 by corrosive substances (Figure 2).

[0018] 3(a), 3(b), and 3(c) are diagrams illustrating an example of a transmission signal and a reception signal transmitted and received by the microcomputer of the corrosion warning device according to an embodiment of the present disclosure. FIGS. 3(a), 3(b), and 3(c) illustrate an example of a transmission signal S1 and a reception signal S2 transmitted and received by the microcomputer 31 of the corrosion warning device 40, corresponding to the stage of corrosion. FIG. 3(a) illustrates an example in which the test part 32 is not corroded or is slightly corroded, and the waveform of the reception signal S2 is almost identical to the waveform of the transmission signal S1. FIG. 3(b) illustrates an example in which the corrosion of the test part 32 has progressed to a certain extent, and the waveform of the reception signal S2 is deformed from the waveform of the transmission signal S1 and the voltage level is reduced. FIG. 3(c) illustrates a state in which the test part 32 has been corroded and disconnected, causing the corrosion detection circuit 22 to break, and the reception signal S2 is not transmitted (and therefore cannot be received).

[0019] Determination circuit 23 compares transmission signal S1 transmitted to test part 32 in corrosion detection circuit 22 with reception signal S2 received from test part 32, and determines which of the above-mentioned Figures 3(a), (b), and (c) applies. If it determines that it corresponds to Figure 3(a), it determines that corrosion detection circuit 22 (and therefore control board 17) is at a stage (referred to as Stage 0) where there is no effect of corrosion. If it determines that it corresponds to Figure 3(b), it determines that control board 17 is at a stage (referred to as Stage 1) before a break in corrosion detection circuit 22 is reached. If it determines that it corresponds to Figure 3(c), it determines that control board 17 is at a stage (referred to as Stage 2) where a break in corrosion detection circuit 22 is reached.

[0020] As described above, the determination circuit 23 determines the stage of corrosion of the test part 32 as one of three stages: stage 0, stage 1, and stage 2, and displays the determination result on the display device 19. This allows the operator of the maintenance device 1 to recognize not only whether the control board 17 is in a stage where the test part 32 is not affected by corrosion at all (corresponding to stage 0) or a stage where the test part 32 has been corroded and broken (corresponding to stage 2), but also whether the control board 17 is in an intermediate stage where the test part 32 has been corroded but has not yet been broken (corresponding to stage 1).

[0021] Therefore, unlike the conventional method in which corrosion of the control board 17 is discovered only after a break in the test part 32 due to corrosion is detected, the worker can know the previous stage (progression stage) of corrosion, so that sufficient preparation time is secured for replacing board components (mounted electronic components or the control board 17 itself) due to corrosion.

[0022] Here, in the corrosion warning device 40 of this embodiment, the transmission of the transmission signal S1 to the corrosion detection circuit 22 (test part 32) and the corresponding judgment by the judgment circuit 23 are not performed continuously, but are performed only for a certain period of time, and this is repeated periodically or irregularly. Considering that corrosion progresses relatively slowly and there is no need to constantly monitor the stage of corrosion progression, constantly transmitting the transmission signal S1 and making judgments is preferable in terms of power costs, but is undesirable in terms of increasing the operating load on the CPU in the control board 17.

[0023] As described above, corrosion warning device 40 provided in working apparatus 1 in this embodiment includes corrosion detection circuit 22 configured by mounting test part 32 on control board 17, the test part 32 having a metal that is less corrosion-resistant to corrosive substances than the electronic components mounted on control board 17, determination circuit 23 as a determination unit that determines the stage of corrosion of test part 32 by comparing transmission signal S1 sent to test part 32 with reception signal S2 received from test part 32 in corrosion detection circuit 22, and display device 19 as a result display unit that displays the determination result determined by determination circuit 23. Determination circuit 23 determines the stage of corrosion of test part 32 in three stages: a stage where there is no corrosion (stage 0), a stage where corrosion has begun but has not yet caused a break in corrosion detection circuit 22 (stage 1), and a stage where corrosion has caused a break in corrosion detection circuit 22 (stage 2).

[0024] Therefore, with corrosion warning device 40 (working device 1 equipped with corrosion warning device 40) in this embodiment, the worker can recognize that control board 17 is not only at a stage where test part 32 is not affected by corrosion at all (corresponding to Stage 0) or at a stage where test part 32 has been broken due to corrosion (corresponding to Stage 2), but also at an intermediate stage (corresponding to Stage 1) where test part 32 is corroded but has not yet broken. Thus, unlike conventional systems, the worker is not only able to discover that corrosion has progressed in control board 17 after a break due to corrosion of test part 32 is detected, but can know the previous stages (progression stages) of corrosion, making it possible to ensure sufficient preparation time for replacing board components (mounted electronic components or control board 17 itself) due to corrosion.

[0025] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above and various modifications are possible. For example, in the above-described embodiment, the determination unit (determination circuit 23) determines the stage of corrosion of the test part 32 based on three stages: a stage where there is no corrosion (stage 0), a stage where corrosion has begun but has not yet caused an open circuit in the corrosion detection circuit 22 (stage 1), and a stage where corrosion has caused an open circuit in the corrosion detection circuit 22 (stage 2). However, the determination may be based on more than these three stages (i.e., multiple stages including the above three stages). Furthermore, the first stage may be subdivided to determine the state of progressing corrosion in more stages, and the results may be displayed on the display device 19.

[0026] Furthermore, in the above-described embodiment, a component mounting device having a parts feeder 13, mounting head 14, and head moving mechanism 15 as working unit 18 was shown as an example of working apparatus 1 equipped with corrosion warning device 40, but working apparatus 1 is not limited to component mounting apparatuses and can be applied not only to printing apparatuses and inspection apparatuses that are devices related to component mounting work, but also to working apparatuses that perform other work other than component mounting work.

[0027] Furthermore, in the above-described embodiment, a resistor is shown as the test part 32, but the test part 32 is not limited to a resistor. Furthermore, in the above-described embodiment, silver is shown as the metal of the test part 32, but this is because silver is the most suitable metal with low corrosion resistance against sulfur-based gases. Therefore, if the corrosive substance is not sulfur-based gases, a metal other than silver can also be used.

[0028] Although the embodiments of the present disclosure have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications, alterations, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components of the above-described embodiments may be combined in any manner as long as they do not deviate from the spirit of the invention. [Industrial Applicability]

[0029] To provide a corrosion warning device that can ensure sufficient preparation time for replacing substrate components that become necessary due to corrosion, and a work device equipped with the corrosion warning device. [Explanation of symbols]

[0030] 1 Work equipment 11 Foundation 12 Printed circuit board holder 13 Parts feeder 14 Mounting head 14N nozzle 15 Head movement mechanism 16 Control Unit 17 Control board (board) 18 Working Section 19 Display device (result display unit) 21 Operation control circuit 22 Corrosion detection circuit 23 Judgment circuit (judgment section) 31 Microcomputer 32 test parts 40 Corrosion warning device S1 Transmit signal S2 received signal

Claims

1. A corrosion warning device that warns of corrosion caused by a corrosive substance of an electronic component mounted on a substrate, a corrosion detection circuit configured by placing a test part on the substrate, the test part having a metal that has lower corrosion resistance to the corrosive substance than the mounted electronic component; a determination unit that determines a corrosion level of the test part by comparing a transmission signal transmitted to the test part with a reception signal received from the test part in the corrosion detection circuit; a result display unit that displays the determination result determined by the determination unit; Corrosion warning device equipped with

2. 2. The corrosion warning device according to claim 1, wherein the determination unit determines the stage of corrosion of the test part in three stages: a stage where the test part is not corroded, a stage where the corrosion has begun but has not yet broken the corrosion detection circuit, and a stage where the corrosion has broken the corrosion detection circuit.

3. 10. The corrosion warning device of claim 1, wherein the test part comprises a resistor.

4. 4. The corrosion warning device of claim 3, wherein said metal comprises silver.

5. 2. The corrosion warning device of claim 1, wherein the corrosive substance is a sulfur-based gas.

6. The corrosion warning device according to claim 1 , wherein the transmission of the transmission signal to the corrosion detection circuit and the determination by the determination unit in response thereto are performed only for a fixed time period, and are repeatedly performed periodically or irregularly.

7. A working device comprising the corrosion warning device according to any one of claims 1 to 6, wherein the board is a control board that controls the operation of a working unit.

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