JP2007024745A - Simplified metal discrimination meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable, nondestructive, and simplified metal discrimination meter capable of easily discriminating lead-free solder from lead solder. <P>SOLUTION: The simplified metal discrimination meter is provided with an easily detachable electrolyte tip made of a material for absorbing and holding an electrolytic solution to be in contact with the surface of a metal to be inspected; a measuring probe having both an easily detachable reference metal electrode to be in contact with the electrolyte tip and an object metal contact terminal to be in contact with the surface of the metal to be inspected; and a function for detecting a potential difference between the reference metal electrode and the metal to be inspected and displaying the potential difference on a display part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to, for example, whether a solder used for an electronic component or an electronic board constituting a product is a lead-free solder (a solder containing no lead) in a business place that manufactures an electronic product, or a lead solder. The present invention relates to a simple metal discriminator useful for easily discriminating whether it is (a solder containing lead).

In recent years, in order to protect the global environment, regulations on the use of substances that have a negative impact on the environment have been required. Specifically, from July 2006, the use of specific hazardous substances in electrical and electronic equipment distributed in EU member states Restriction directives are implemented. This directive is called the RoHS directive after taking the initials of Restriction of Hazardous Substances.

Here, specific harmful substances are lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyl, and polybrominated diphenyl ether. In general electric / electronic devices, lead contained in solder used when soldering an electronic component to an electronic board is a problem. Conventionally, the composition of solder that has been generally widely used is lead solder containing 63% tin and 37% lead. However, it is technically and economically difficult to completely eliminate the use of lead solder, and there are electronic parts and electronic devices that are exempted from the RoHS directive. Specifically, lead-free solder and lead solder coexist in an office that manufactures electronic products. Therefore, in the management of electronic equipment, when it is unclear whether the solder used for electronic components and electronic boards is lead solder or lead-free solder, it has become necessary to determine whether it is lead solder or lead-free solder. However, it was difficult to distinguish easily on the appearance.

In order to solve the above problems, an invention such as a lead detection jig (Patent Document 1) has been introduced.
JP 2001-208742 A

  By the way, the conventional techniques as described above have the following problems to be solved. That is, there is no indicator for detection that can distinguish between lead solder and lead-free solder safely and easily without impairing the appearance. There is an indicator that is said to detect lead, but it is necessary to use a chemically reactive indicator whose safety to the human body and electronic parts is unknown, and to substances other than lead as well as lead There is no indicator that can distinguish between lead solder and lead-free solder easily and safely without damaging the appearance, such as the need for pretreatment to polish the solder surface. On the other hand, there are conventional analyzers for identifying substances such as fluorescent X-ray detection analyzers and emission analyzers, but the analyzers are expensive and can be used easily at ordinary electrical and electronic equipment manufacturing establishments. There was a problem that I could not.

  The present invention has been made paying attention to the above points, and can be easily used at any electric or electronic equipment manufacturing establishment regardless of the scale of the establishment. Lead solder and lead-free solder An object of the present invention is to provide a simple metal discriminator that can easily discriminate between the two.

  The present invention adopts the following configuration in order to solve the above points.

<Configuration 1>
Standard with an integrated measuring probe that has an electrolyte tip that contacts the metal surface to be inspected and is easy to attach and detach, a reference metal electrode that contacts the electrolyte tip and is easy to attach and detach, and a target metal contact terminal that contacts the surface of the metal to be inspected A metal with a large surface area with a simple metal discriminator, which has the function of detecting the potential difference between the metal electrode and the metal to be inspected and displaying the potential difference due to the difference in ionization tendency that differs for each metal type on the display. Suitable for surface measurement.

<Configuration 2>
The reference from the target metal contact terminal that contacts the surface of the metal to be inspected and the split-type measuring probe that has the reference metal electrode that comes in contact with the surface of the metal to be inspected and can be easily attached and detached, and the electrolyte chip. This is a simple metal discriminator characterized by detecting the potential difference between the metal electrode and the metal to be inspected and displaying the potential difference due to the difference in ionization tendency that differs for each metal type on the display unit. It is suitable for measurement of small metal surfaces on which circuit nets are constructed.

  In the present invention, for example, when it is desired to specify whether a metal surface of an electronic component is lead solder or lead-free solder at an electric / electronic equipment establishment, the metal surface to be inspected should be sufficiently soiled with alcohol or the like. It is desirable to prevent errors caused by dropping and dirt. In addition, the electrolyte solution used in the simple metal discriminator of the present invention is chemically stable and supplies sufficient ions that are difficult to cause chemical reactions such as oxidation and chlorination with the metal to be in contact within the time to be measured and can ensure conductivity. A sodium chloride aqueous solution having a high degree of ionization that can be used is desirable.

Hereinafter, the present invention will be described in detail with reference to examples.

  FIG. 1 shows an embodiment of an integrated measuring probe type simple metal discriminator according to the present invention. This simple metal discriminator includes an electrolyte chip 11, an integrated measurement probe 3 including a reference metal electrode 12 and a target metal contact terminal 15, a reference metal electrode side cable 53, an inspection target metal side cable 54, a display unit 6 and an operation unit 7. A main body portion 5 is provided.

The inspection target metal 1 is located on the insulator 2. An electrolyte solution such as sodium chloride is included in the electrolyte chip 11 to come into contact with the reference metal electrode 12 and the inspection object metal 1, and the inspection object metal 1 and the reference metal electrode 12 are electrically connected by ions of the electrolyte solution through the electrolyte chip 11. Connected to. Due to the ionization of the surface metal around each metal contact surface of the electrolyte chip 11, a potential difference due to the difference in ionization tendency between the inspection target metal 1 and the reference metal electrode 12 occurs between the target metal terminal 15 and the reference metal electrode 12. The potential difference is transmitted to the main body 5 via the reference metal electrode side cable 53 and the inspection target metal side cable, and the measured potential difference is displayed on the display unit 6.

[Integrated measurement probe]
FIG. 2 is a configuration diagram showing the configuration of the integrated measurement probe 3 of the present invention.

As shown in FIG. 2, the electrolyte chip 11 is attached to the reference metal electrode 12 with a structure that can be easily attached and detached, and is fixed to the reference metal electrode 12 with a holding screw 19. The reference metal electrode 12 is attached to the reference electrode conductor 14 with a structure that can be easily attached and detached, and is fixed by a retaining screw 13. The retaining screw 13 has a structure that does not contact the electrolyte chip 11 and prevents the influence of ionization of the surface metal of the retaining screw 13. The reference electrode conductor 14 is connected to the reference metal electrode side probe connector 51. On the other hand, the target metal contact terminal 15 is connected to the test target metal side probe connector 52 via the coil spring 16 and the target metal terminal conductor 17 that absorb the unevenness of the test target metal 1 in order to obtain stable contact with the test target metal 1. ing.

  The electrolyte chip 11 is made of a fiber material having a large water retention property or a porous polymer material, and contains an electrolyte solution such as sodium chloride so as to come into contact with the reference metal electrode 12 and the inspection target metal 1. For this reason, since the electrolyte chip 11 is contaminated by metal ions of the inspection target metal 1 when contacting the inspection target metal 1, it is desirable to replace the electrolyte chip 11 with a new electrolyte chip 11 every measurement, and the structure can be easily attached and detached. Further, since the reference metal electrode 12 is also contaminated and deteriorated by the electrolyte solution, the reference electrode conductor 14 can be easily attached and detached.

  In particular, since the potential difference to be measured is small between metals having similar ionization tendencies, a structure that can be easily attached and detached so that a metal having the same composition as that of the metal to be discriminated can be selected as the reference metal electrode 12 in order to improve measurement accuracy. . For example, when determining whether lead-free solder or lead solder is used as the reference metal electrode 12, the test target metal 1 is the same lead solder as the reference metal electrode 12, and there are no interference ions due to contamination. If the conditions are optimum, the measured potential difference is about 0 mV, and it can be easily determined that the inspection target metal 1 is identified as lead solder.

[Main unit]
FIG. 3 is a circuit block diagram showing the configuration of the main body 5 of the present invention. The potential difference detected by the integrated measurement probe 3 is input to the reference metal electrode side main body connector 55 and the inspection target metal side main body connector 56, and the potential difference is amplified to an output voltage that matches the input specifications of the A / D converter 23. The amplifier circuit 22 is entered. The amplifier circuit 22 has a sufficient input current to avoid the influence of electrode reaction that occurs around the contact surface between the reference metal electrode 12 and the inspection target metal 1 and the electrolyte chip 11 when a current flows for stable detection of a potential difference. Use a small amplifier circuit. The amplified potential difference is converted from an analog voltage to a digital signal by the A / D conversion unit 23, and is controlled by the display control unit 24 according to the display content designated by the operation unit 7. The potential difference is converted into a digital numerical value by the display unit 6. Displayed as

[Example 2]
FIG. 4 is an example of a split type measuring probe type simple metal discriminator according to the present invention.

This simple metal simple discriminator includes an electrolyte chip 11, a split-type measuring probe 33 made up of a reference metal electrode 12, a reference metal electrode side cable 53, an inspection object metal side cable 54, a main body part 5 made up of a display unit 6 and an operation unit 7. Is provided. The inspection target metal 1 and the chip part soldering part 31 are located on a printed circuit board 32. An electrolyte solution such as sodium chloride is included in the electrolyte chip 11 to come into contact with the reference metal electrode 12 and the inspection object metal 1, and the inspection object metal 1 and the reference metal electrode 12 are electrically connected by ions of the electrolyte solution through the electrolyte chip 11. Connected to. The soldering part 31 of the chip component of the inspection object metal 1 and the reference metal electrode 12 are electrically connected via the electrolyte chip 11, and the inspection object is obtained by ionization of the metal around the surface of the soldering part 31 and the reference metal electrode 12. A potential difference is generated between the soldering portion 31 and the reference metal electrode 12 due to the difference in ionization tendency between the soldering portion 31 of the metal 1 chip component and the reference metal electrode 12. The inspection target metal 1 side is transmitted from the soldering portion 31 via the conductor circuit pattern 34 to the connection terminal clip 35 and connected to the inspection target metal side main body connector 56 of the main body portion 5 via the inspection target metal side cable 54. Is done. The reference metal electrode 12 side is transmitted from the reference metal electrode 12 to the reference metal electrode side probe connector 51, the reference metal electrode side cable 53, and the inspection target metal side main body connector 55 of the main body 5, and is measured by the display unit 6. The potential difference is displayed.

The electrolyte chip 11 is made of a fiber material having a large water retention capacity or a porous polymer material, and contains an electrolyte solution such as sodium chloride so as to come into contact with the reference metal electrode 12 and the metal 1 to be inspected. Since the metal ions of the object metal 1 to be inspected are contaminated when contacting the metal 1, it is desirable to replace the electrolyte chip 11 with a new one every measurement, and the structure can be easily attached and detached.
In addition, since the reference metal electrode 12 is also contaminated and deteriorated by the electrolyte solution, the reference electrode conductor 14 can be easily attached and detached.

  Since the reference metal electrode 12 has a small potential difference particularly between metals having similar ionization tendency, the reference metal electrode 12 can be easily attached and detached so that a metal having the same composition as the metal to be discriminated can be selected as the reference metal electrode 12 in order to improve measurement accuracy. Structure. For example, when determining whether lead-free solder or lead solder is used as the reference metal electrode 12, the test target metal 1 is the same lead solder as the reference metal electrode 12, and there are no interference ions due to contamination. If the conditions are optimum, the measured potential difference is about 0 mV, and it can be easily determined that the inspection target metal 1 is identified as lead solder.

[Example 3]
FIG. 5 shows an embodiment of a simple metal discriminator with a probe according to the present invention.

The structure of this simple metal simple discriminator constitutes the probe-equipped main body 41 with a structure in which the split measurement probe 33 and the main body 5 are integrated with respect to the second embodiment of FIG. The connection terminal clip 35, the electrolyte chip 11, the reference metal electrode 12, the display unit 6, and the operation unit 7 are provided, and the operation is the same as that of the second embodiment. Compared with the second embodiment, the probe-equipped main body 41 according to the third embodiment has a structure that is small and light and convenient to carry because the split measurement probe 33 and the main body 5 are integrated. Suitable for use at business sites or for use outside business sites.

[Uses and effects]
The simple metal discriminator of the present invention is manufactured, for example, in an establishment that manufactures electronic products, when it is desired to check whether the received electronic board or electronic component uses lead-free solder in the component acceptance inspection process. When it is desired to confirm whether lead-free solder is used during the process, it can be easily confirmed by using the simple metal discriminator of the present invention without using an expensive analyzer.

It is a block diagram of the simple metal discriminator of Example 1 of this invention. It is a block diagram which shows the structure of the measurement probe of this invention. It is a circuit block diagram which shows the structure of the main-body part of this invention. It is a block diagram of the simple metal discriminator of Example 2 of this invention. It is a block diagram of the simple metal discriminator of this invention Example 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Test object metal 2 Insulator 3 Integrated measurement probe 5 Main body part 6 Display part 7 Operation part 11 Electrolytic chip 12 Reference metal electrode 13 Fastening screw 14 Reference electrode conductor 15 Target metal contact terminal 16 Coil spring 17 Target metal terminal conductor 19 Holding down Screw 22 Amplifying circuit 23 A / D conversion unit 24 Display control unit 31 Soldering unit 32 Printed circuit board 33 Split type measurement probe 34 Conductor circuit pattern 35 Connection terminal clip 41 Body with probe 51 Reference metal electrode side probe connector 52 Inspection target metal side Probe connector 53 Reference metal electrode side cable 54 Inspection target metal side cable 55 Reference metal electrode side main body connector 56 Inspection target metal side main body connector

Claims (1)

The surface metal of the reference metal electrode that is easy to attach / detach via an easily attachable / detachable electrolyte chip made of a material that absorbs and holds the electrolyte solution between the surface of the metal to be inspected and the reference metal electrode for potential difference measurement that is easy to attach / detach A simple metal discriminator characterized in that it has a means for measuring the potential difference between the potential of the reference metal electrode due to ionization of the metal and the potential of the metal to be inspected due to ionization of the surface metal to be inspected, and is portable easily anywhere.

Images