JP4124895B2 - Electronic component characteristic inspection method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention measures the contact resistance between the measuring terminal of the inspection device and the lead wire of the electronic component in advance during the characteristic inspection of electronic components such as diodes and resistors, and performs the original characteristic inspection after improving the contact state. those concerning the characteristic inspection method of the electronic component which is adapted to implement.
[0002]
[Prior art]
This kind of electronic component characteristic inspection method will be described with reference to FIG.
In the figure, DUT is a lead-type electronic component, and a diode is shown here.
[0003]
Measurement terminals D1, D2 and D3, D4 of the inspection device are brought into contact with the lead wires 1a, 1b of the DUT. Further, relays RY1 to RY4 each having a movable contact for switching and fixed contacts a and b are connected to the measurement terminals D1 to D4 as shown in the figure.
That is, the relay RY1 is connected to the measurement terminal D1, the relay RY2 is connected to the measurement terminal D2, the relay RY3 is connected to the measurement terminal D3, and the relay RY4 is connected to the measurement terminal D4.
Here, the mode when the movable contacts of all the relays RY1 to RY4 are connected to the fixed contact a is set to mode 1, and the mode when the movable contacts of all the relays RY1 to RY4 are connected to the fixed contact b is set to the mode. 2.
In the mode 1, the measurement terminals D1 and D3 are connected to the DC power sources E1 and E2, respectively, and the other measurement terminals D2 and D4 are connected to the photocouplers PC1 and PC2 via the resistors R1 and R2, respectively.
[0004]
In the above configuration, prior to performing the original characteristic inspection of the DUT, first, the contact state between the DUT and the measurement terminals D1 to D4 of the characteristic inspection apparatus is inspected.
That is, in the circuit configuration as described above, when the switches SW1 and SW2 are turned on and the measurement terminals D1 and D2 on the DC power supply E1 side are in contact with the lead wire 1a of the DUT, the photocoupler PC1 is connected via the resistor R1. Current flows and the device is turned on. In this case, a signal for taking the contact state between the measurement terminals D1, D2 and the lead wire 1a as OK is taken out.
[0005]
On the other hand, when the measurement terminals D1 and D2 are not in contact with the lead wire 1a, no current from the DC power supply E1 flows through the photocoupler PC1. In such a case, the photocoupler PC1 is turned off, and a signal with NG as the contact state between the measurement terminals D1 and D2 and the lead wire 1a is taken out.
Similarly, the direct current power supply E2 side can visually check the contact state between the measurement terminals D3 and D4 and the lead wire 1b by the blinking of the photocoupler PC2.
[0006]
Next, when it is confirmed that the measurement terminal and the lead wire are in contact with each other on the lead wire 1a side and the lead wire 1b side, all the relays are connected to the fixed contact b by means not shown, and the mode 2 and Become. At that time, the switch SW3 is turned on, and a current for characteristic inspection flows from the DC power supply E3 to the DUT via the measurement terminals D1 and D3. Then, the voltage at both ends of the DUT is measured by the voltmeter VF via the measurement terminals D2 and D4 by the current flowing through the DUT.
[0007]
[Problems to be solved by the invention]
Prior to the original characteristic inspection, conventionally, the contact state between the lead wires 1a and 1b and the measurement terminals D1 to D4 has been inspected by the above method. That is, the contact state is actually determined based on whether or not a minute current in the range of 10 to 100 mA flows, and the actual contact resistance between the measurement terminals D1 to D4 and the lead wires 1a and 1b is ignored. Was the inspection method. In the inspection method as described above, even if the measurement terminals D1 to D4 are in contact with the lead wires 1a and 1b, the contact resistance at that time varies every time when the electronic components to be inspected are exchanged and contacted each time. When an original test current of about 50 to 200 A is passed instantaneously when the contact resistance is large, a spark occurs between the measurement terminals D1 to D4 and the lead wires 1a and 1b, and the measurement terminals D1 to D4 and the leads There was a problem to be solved that the lines 1a and 1b are dissolved and the subsequent inspection becomes impossible.
[0008]
The present invention has been made to solve the above-described problems, and enables the contact resistance value between the measurement terminal of the characteristic inspection apparatus and the lead wires 1a and 1b of the lead-type electronic component DUT to be inspected. An object of the present invention is to provide a method for inspecting the characteristics of an electronic component, in which the contact state between the measuring terminals D1 to D4 and the lead wire is improved by the resistance inspection current I1, and the original characteristic inspection can be performed accurately. It is.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, a part of one lead wire (1a) of the lead-type electronic component (DUT), the first measurement terminal (S1), the first resistor (R1), and the first Forming a first series circuit in which a DC power source (E1) and a second measurement terminal (S2) are connected in series;
A current of 10 to 30 A is passed through the first series circuit, the contact resistance (Rd) between the first measurement terminal (S1) and one lead wire (1a), and the second measurement terminal (S2) and one lead wire. Reduce the contact resistance (Re) with (1a)
Based on the current value (I1) flowing through the first series circuit and the voltage value (vr1) between the first measurement terminal (S1) and the second measurement terminal (S2), the first measurement terminal (S1) Calculate the contact resistance (Rd) with one lead wire (1a) and the contact resistance (Re) between the second measurement terminal (S2) and one lead wire (1a),
Part of the other lead wire (1b) of the lead-type electronic component (DUT), the third measurement terminal (S3), the second resistor (R2), the second DC power supply (E2), and the fourth measurement terminal (S4) to form a second series circuit connected in series,
A current of 10 to 30 A is passed through the second series circuit, the contact resistance between the third measurement terminal (S3) and the other lead wire (1b), and the fourth measurement terminal (S4) and the other lead wire (1b). The contact resistance with
Based on the current value flowing through the second series circuit and the voltage value between the third measurement terminal (S3) and the fourth measurement terminal (S4), the third measurement terminal (S3) and the other lead wire (1b) ) And the contact resistance between the fourth measurement terminal (S4) and the other lead wire (1b),
Lead type electronic component (DUT), one lead wire (1a) of lead type electronic component (DUT), first measurement terminal (S1), third resistor (R3), and third DC power source (E3) A third series circuit in which the fourth measurement terminal (S4) and the other lead wire (1b) of the lead type electronic component (DUT) are connected in series;
A current of 50 to 200 A is passed through the third series circuit,
A voltage drop of the lead type electronic component (DUT) is measured by a voltmeter (VF) connected in parallel to the lead type electronic component (DUT) via the second measurement terminal (S2) and the third measurement terminal (S3). An electronic component characteristic inspection method is provided.
[0012]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to FIG.
In FIG. 1, DUT is a lead-type electronic component such as a diode. Measurement terminals S1 to S2 of the characteristic inspection test apparatus are brought into contact with the lead wire 1a of the DUT, and measurement terminals S3 to S4 of the inspection test apparatus are brought into contact with the lead wire 1b.
[0013]
The measurement terminal S1 is connected to relays RY11 and RY13, and the measurement terminal S2 is connected to relays RY12 and RY14. A voltmeter VR1 for measuring a voltage described later between the fixed contacts a and a of the relays RY11 and RY12. Is connected.
A power supply E1 for flowing the inspection current I1 is connected between the fixed contacts a and a of the relays RY13 and RY14.
[0014]
Relays RY15 and RY17 are connected to measurement terminal S3, and relays RY16 and RY18 are connected to measurement terminal S4. A voltmeter VR2 for measuring a voltage to be described later is provided between fixed contacts a and a of relays RY15 and RY16. It is connected. In addition, a power source E2 for flowing an inspection current I1 is connected between the fixed contacts a and a of the relays RY17 and RY18.
[0015]
Further, a power source E3 for flowing a test current IS is connected between the fixed contact b of the relay RY11 and the fixed contact b of the relay RY18 via a resistor R3 and a switch SW3.
Further, a voltmeter VF for measuring a voltage described later is connected between the fixed contact b of the relay RY12 and the fixed contact b of the relay RY17.
Note that nothing is connected to the fixed contact b of the relays RY13, RY14, RY15, RY16.
[0016]
In the above configuration, in order to inspect the contact state between the measurement terminals S1 and S2 and the lead wire 1a, the movable contacts of the relays RY11, RY12, RY13, and RY14 are brought into contact with the fixed contact a to be in the mode 1 state.
Next, when the switch SW1 is turned on, the inspection current I1 flows from the power source E1 through the path of the resistor R1, the relay RY13, the measurement terminal S1, the lead wire 1a, the measurement terminal S2, the relay RY14, and the switch SW1.
In this embodiment, the inspection current I1 is in the range of 10 to 30A.
[0017]
A current value in the above range is particularly significant in the present invention.
That is, even if the surface of the lead wires 1a and 1b is soiled, burrs of the mold formed at the time of resin molding adhere, and even if the contact with the measurement terminal is incomplete, the inspection current I1 in the above range is applied to cause a partial minute spark. To improve contact. On the other hand, it has been found from various experimental results that contact is not complete at a current smaller than this range, and that a spark larger than this range results in a large spark and the measurement terminals and lead wires are welded.
Therefore, the above current value range is preferable.
[0018]
Further, at the same time when the inspection current I1 is supplied from the power source E1, the voltage between the measurement terminals S1 and S2 is measured by the voltmeter VR1, and if the current value is within the specified value, the contact resistance is small and the contact state is good. It is shown that.
[0019]
Here, the voltage measured by the voltmeter VR1 when the inspection current I1 is supplied is defined as vr1, and this vr1 is considered.
In the illustrated case, the resistance of the wiring L1 portion is Ra, the resistance of the portion corresponding to the length Lo of the lead wire 1a is Rc, the resistance of the wiring L2 portion is Rb, and the contact resistance between the measurement terminal S1 and the lead wire 1a is When Rd is the contact resistance Re between the measurement terminal S2 and the lead wire 1a, the voltage vr1 is expressed by the following equation.
vr1 = I1 * (Ra + Rb + Rc + Rd + Re) (1)
[0020]
If Ra, Rb, and Rc are obtained in advance by the above equation (1), contact resistance Rd, by subtracting I1 * (Ra + Rb + Rc) from vr1 measured in mode 1 of FIG. Re is understood.
[0021]
Also on the lead wire 1b side, the contact resistances of the measurement terminals S3 and S4 are obtained in the mode 1 in the same manner as described above.
Although not shown, the numerical values vr1 and vr2 measured by the voltmeter VR1 and the voltmeter VR2 are stored and held by known means.
If VR1 = I1 * (Rd + Re) is larger than the specified value, the diode to be inspected is removed from the measurement station before entering the mode 2 mode described later.
[0022]
On the other hand, if vr1 and vr2 of the diode to be inspected are specified values, the next mode is entered. Then, Ru switched from off the switches SW1, SW2 all fixed contact a of relay RY11~RY18 the fixed contact b. That is, it is connected to a power source E3 that supplies a test current via a fixed contact b of relays RY11 and RY18, and is connected to a voltmeter VF that measures a voltage drop of a diode by relays RY12 and RY17.
[0023]
In the case of the above mode 2, the switch SW3 is turned on, and a current of 50 to 200 A is supplied as a test current IS from the power source E3 to the diode. This current value is determined by the type of diode. The forward voltage drop of the diode due to the test current IS is measured by a voltmeter VF. If the measurement result of the current value is within the specified value, it is stored and held as a non-defective product.
[0024]
When the test is thus completed, the switch SW3 is turned off, and the diode is transported to the next station. Relays RY11-RY18 all return to mode 1.
The power supplies E1, E2, E3 are all constant current power supplies.
[0025]
As described above, the present invention is characterized in that it is increased to 10 to 30 A, unlike the conventional inspection current of 10 to 100 mA for inspecting the contact resistance. It is not effective for removing foreign matter and the like, and is 30 A or less in order to minimize damage to the product to be inspected.
[0026]
That is, in the prior art, since the lead wires 1a and 1b and the measurement terminals D1 to D4 are slightly in contact with each other and a current flows even if the contact resistance is large, a spark is generated by a test current that is passed during an original characteristic current inspection. It was.
Therefore, in the present invention, a relatively large current in the range of 10 to 30 A is passed at an early stage to inspect the contact resistance, and the contact state is to be improved satisfactorily by such current.
[0027]
It should be noted that the magnitude of the current that is initially supplied is specifically determined based on the size of the terminal of the product to be inspected, the magnitude of the original test current, and the like. As a result, even if dirt, oxidation, minute foreign matter, etc. on the surface of the lead wires 1a, 1b are present between the measurement terminals S1, S2, S3, S4, the contact state between the two becomes good, and a spark or the like can be performed as in the prior art. No waking.
[0028]
In the above embodiment, the diode is used as the DUT. However, the present invention can also be used for other elements having an axial lead type electronic component. Further, the relays RY11 to RY18 and switches SW1 to SW3 shown in FIG. 1 may be replaced with electronic elements.
[0029]
【The invention's effect】
As described above, in the method for inspecting characteristics of an electronic component according to the present invention, the current for inspecting the contact resistance is first determined in the range of 10 to 30 A, and the current value is increased as compared with the conventional method. Dirt on the contact surface between 1a and 1b and measurement terminals S1 and S2, that is, thin burrs during molding, adhesion of solder flux, and the like can be removed. This makes it possible to accurately perform the original characteristic test in a good contact state. Further, prior to conducting the original characteristic test, by measuring the contact resistance value between the lead wires 1a and 1b and the measurement terminals S1, S2, S3 and S4, if the contact resistance is extremely large, the subsequent characteristic test is performed. Can be canceled. As a result, there is an effect that it is possible to eliminate damage due to wear of the measurement terminal, spark of the lead wire, or the like.
[Brief description of the drawings]
FIG. 1 is a circuit diagram for carrying out an electronic component characteristic inspection method according to an embodiment of the present invention.
FIG. 2 is a circuit diagram for carrying out a conventional characteristic inspection method for electronic components.
[Explanation of symbols]
DUT leaded electronic components 1a, 1b leads S1~S4 measuring terminals RY11~RY18 relay E1~E3 power <br/> VR1, VR2 voltmeter VF voltmeter

Claims (1)

Part of one lead wire (1a) of the lead-type electronic component (DUT), the first measurement terminal (S1), the first resistor (R1), the first DC power supply (E1), and the second measurement terminal (S2) to form a first series circuit connected in series,
A current of 10 to 30 A is passed through the first series circuit, the contact resistance (Rd) between the first measurement terminal (S1) and one lead wire (1a), and the second measurement terminal (S2) and one lead wire. Reduce the contact resistance (Re) with (1a)
Based on the current value (I1) flowing through the first series circuit and the voltage value (vr1) between the first measurement terminal (S1) and the second measurement terminal (S2), the first measurement terminal (S1) Calculate the contact resistance (Rd) with one lead wire (1a) and the contact resistance (Re) between the second measurement terminal (S2) and one lead wire (1a),
Part of the other lead wire (1b) of the lead-type electronic component (DUT), the third measurement terminal (S3), the second resistor (R2), the second DC power supply (E2), and the fourth measurement terminal (S4) to form a second series circuit connected in series,
A current of 10 to 30 A is passed through the second series circuit, the contact resistance between the third measurement terminal (S3) and the other lead wire (1b), and the fourth measurement terminal (S4) and the other lead wire (1b). The contact resistance with
Based on the current value flowing through the second series circuit and the voltage value between the third measurement terminal (S3) and the fourth measurement terminal (S4), the third measurement terminal (S3) and the other lead wire (1b) ) And the contact resistance between the fourth measurement terminal (S4) and the other lead wire (1b),
Lead type electronic component (DUT), one lead wire (1a) of lead type electronic component (DUT), first measurement terminal (S1), third resistor (R3), and third DC power source (E3) A third series circuit in which the fourth measurement terminal (S4) and the other lead wire (1b) of the lead type electronic component (DUT) are connected in series;
A current of 50 to 200 A is passed through the third series circuit,
A voltage drop of the lead type electronic component (DUT) is measured by a voltmeter (VF) connected in parallel to the lead type electronic component (DUT) via the second measurement terminal (S2) and the third measurement terminal (S3). A method for inspecting characteristics of electronic parts.

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