JPH0519009A - Esd tester - Google Patents

Abstract

PURPOSE:To obtain an ESD tester which does not require use of a high voltage power source and is appropriate for mass production. CONSTITUTION:Relays RL1 to RLm connect capacitors C1 to Cs in parallel via a resistor R1 between an input terminal 1 and a ground terminal 2. Voltage is applied between the input terminal 1 and the ground terminal 2 to charge the voltage to the capacitors C1 to Cs. The relays RL1 to RLm are switched so that the capacitors C1 to Cs are connected in series between the ground terminal 2 and an output terminal 3. Thus voltage with voltage charged to the capacitors C1 to Cs added is discharged to the output terminal 3. Even if low voltage is applied to the input terminal 1, high voltage can be discharged to the output terminal 3. Therefore use of a high voltage power source is not necessary, reducing a weight of an apparatus. In addition, selection of the number of capacitors C1 to Cs allows different kinds of voltage to be output to the output terminal 3, resulting in flexibility and appropriateness for mass production.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ESD (electro-static discharge) test apparatus constructed without using a high voltage source.

[0002]

2. Description of the Related Art FIG. 3 is a circuit diagram showing a conventional ESD test apparatus. One end of the charging current limiting resistor R ₁ is connected to the input terminal 1. The relay RL ₀ has its contact a connected to the other end of the resistor R ₁ and its contact b connected to the output terminal 3. One electrode of the capacitor C ₀ is connected to the pole side c of the relay RL ₀ , and the other electrode is connected to the ground terminal 2. The output terminal 3 is selectively connected to the output terminals 4 to n by switching the relays RL _{m + 1 to} RL _n (m, n; any positive integer). A high-voltage power source E ₀ is connected between the input terminal 1 and the ground terminal 2.

Next, the operation of the above-mentioned ESD test apparatus will be described. First, the pole side c of the relay RL ₀ and the contact a
Are connected to each other, and a voltage based on the power source E ₀ is applied to the input terminal 1 to store an electric charge in the capacitor C ₀ . Next, the relay RL ₀ is switched to connect the pole side c to the contact b. As a result, the electric charge stored in the capacitance C ₀ is discharged to the output terminal 3. In this case, by switching the relays RL _{m + 1 to} RL _n , the electric charge stored in the capacitor C ₀ is selectively discharged to the output terminals 4 to n.

[0004]

However, in the above-mentioned conventional ESD test apparatus, the high-voltage power supply E ₀ is provided in order to increase the input voltage. For this reason,
There is a problem that a means for protecting the device from high voltage is required in consideration of safety, which increases the weight of the ESD test device. Further, since the conventional ESD test device is dedicated to a predetermined voltage, it is not suitable for mass production and there is a problem that the manufacturing cost is high.

The present invention has been made in view of the above problems, and an object thereof is to provide an ESD test apparatus which does not require the use of a high voltage power source and is suitable for mass production.

[0006]

An ESD test apparatus according to the present invention has a first resistor whose one end is connected to an input terminal, and a first resistor connected in parallel between the other end of the first resistor and a ground terminal. Switching means for switching a plurality of capacitors to be connected and a connection state of the plurality of capacitors and connecting at least one capacitor of the plurality of capacitors in series between the ground terminal and the output terminal. And having.

[0007]

In the present invention, the first resistor for limiting the current at the time of charging is provided, and the plurality of capacitors are connected in parallel between the other end of the first resistor and the ground terminal. By applying a voltage to the terminals, charges are stored in the plurality of capacitors. After that, the switching means switches the connection state of the plurality of capacitors to connect at least one of the plurality of capacitors in series between the ground terminal and the output terminal. In this case, the electric charge charged in the capacitance connected in series is discharged to the output terminal. For this reason,
Even if a low voltage is applied to the input terminal, a high voltage can be discharged to the output terminal. Therefore, the ESD according to the present invention
Since it is not necessary to use a high-voltage power supply in the test device, the weight of the device can be reduced. Further, after accumulating electric charges in a plurality of capacitors, various voltages can be output to the output terminal by selecting the number of capacitors connected between the ground terminal and the output terminal. Therefore, the ESD test apparatus according to the present invention has versatility and is suitable for mass production, so that its manufacturing cost is low.

In the present invention, a second resistor can be connected between the plurality of capacitors and the output terminal. In this case, the output voltage can be set based on the resistance value of the second resistor.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an ESD according to a first embodiment of the present invention.
It is a circuit diagram which shows a test apparatus. One end of the charging current limiting resistor R ₁ is connected to the input terminal 1. The contacts a of the relays RL _{1 to} RL _S are connected to the other end of the resistor R ₁ . Each of the capacitors C _{1 to} C _S has one electrode connected to the pole side c of the relays RL _{1 to} RL _S.
The other electrode of the capacitance C ₁ is connected to the ground terminal 2 and the capacitance C 1
The other electrodes of _{2 to} C _S are relays RL _{S + 1 to} RL, respectively.
It is connected to the pole side c of _m (m = 2S-1). The contacts a of the relays RL _{S + 1 to} RL _m are connected to the ground terminal 2. The contacts b of the relays RL _{1 to} RL _S-1 are connected to the contacts b of the relays RL _{S + 1 to} RL _m , respectively. The contact b of the relay RL _S is connected to the output terminal 3.

[0011] The output terminal 3 is connected to one end of the relay RL m _{+ 1} through RL _n, the other end of the relay RL m _{+ 1} through RL _n is also connected to the output terminal 4 to n, the relay RL m _{+ 1}
The output terminal 3 is selectively connected to the output terminals 4 to _n by switching the output terminals 4 to RL _n .

Next, the operation of the ESD test circuit according to this embodiment described above will be described. First, the pole side c of the relays RL _{1 to} RL _m and the contact a are connected. In this case, the capacitors C _{1 to} C _S are connected in parallel between the input terminal 1 and the ground terminal 2. Then, by applying a voltage between the input terminal 1 and the ground terminal 2, this voltage is charged in the capacitors C _{1 to} C _S. Next, the relays RL _{1 to} RL _m are switched to connect the pole side c to the contact b. This allows
Since the capacitors C _{1 to} C _S are connected in series between the ground terminal 2 and the output terminal 3, the voltage charged in the capacitors C _{1 to} C _S is added between the ground terminal 2 and the output terminal 3. Generated voltage is generated, and the added voltage is discharged to the output terminal 3. Further, by switching the relays RL _{m + 1 to} RL _n , the added voltage charged in the capacitors C _{1 to} C _S is selectively discharged to the output terminals 4 to n.

According to this embodiment, even if a low voltage is applied to the input terminal 1, a high voltage can be discharged to the output terminal 3. Therefore, in the ESD test apparatus according to the present embodiment, it is not necessary to use a high-voltage power supply and it is not necessary to provide a means for protecting the apparatus from high voltage, so that the weight of the apparatus can be reduced. In addition, the relays RL _{1 to} RL _m
By selecting the number of capacitors C _{1 to} C _S connected between the ground terminal 2 and the output terminal 3, various voltages can be output to the output terminal 3. Therefore, the ESD test apparatus according to this embodiment has versatility and is suitable for mass production.

For example, in the conventional EIAJ system ESD test apparatus shown in FIG. 3, C ₀ = 200 pF and E ₀ =
In order to obtain an output characteristic equivalent to that obtained when the voltage is 250 V, in this embodiment, for example, S
= 5 and the capacitors C _{1 to} C ₅ are set to 1000 pF, respectively. In this case, by setting the voltage applied between the input terminal 1 and the ground terminal 2 to, for example, about 50 V, it is possible to obtain an output characteristic equivalent to that of the conventional one.

FIG. 2 shows an ESD according to the second embodiment of the present invention.
It is a circuit diagram which shows a test apparatus. The first embodiment is the first
Since the resistor R ₂ is inserted in the output section of the embodiment of FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals in FIG. 2 and detailed description thereof will be omitted.

That is, in this embodiment, the resistor R ₂ is inserted between the output terminal 3 and the contact b of the relay RL _S that switches the connection state of the final-stage capacitance C _S.

In this case, the operation is similar to that of the first embodiment, but the output voltage can be set based on the resistance value of the resistor R ₂ . Thereby, the MIL type ESD test device can be configured.

[0018]

As described above, according to the present invention, at least one of the plurality of capacitors is switched by switching the connection state of the plurality of capacitors connected in parallel between the input terminal and the ground terminal. Since the capacitance is connected in series between the ground terminal and the output terminal, even if a low voltage is applied to the input terminal, a high voltage can be discharged to the output terminal. Therefore, it is not necessary to use a high-voltage power source, and the weight of the ESD test device can be reduced. Further, by selecting the number of capacitors connected between the ground terminal and the output terminal,
Different output voltages can be obtained. Therefore, the ESD test apparatus according to the present invention has versatility and is suitable for mass production, so that its manufacturing cost is low.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an ESD test apparatus according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing an ESD test apparatus according to a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a conventional ESD test device.

[Explanation of symbols]

1 to n; terminals C _{0 to} C _S ; capacitors R ₁ and R ₂ ; resistors RL _{1 to} RL _n ; relays a and b; relay contacts c; relay pole side E ₀ ; power supply

Claims (2)

[Claims] 1. A first resistor having one end connected to an input terminal, a plurality of capacitors connected in parallel between the other end of the first resistor and a ground terminal, and a plurality of capacitors connected to the first resistor. An ESD test apparatus comprising: switching means for switching the connection state of the capacitors and connecting at least one of the plurality of capacitors in series between the ground terminal and the output terminal. 2. The ESD test apparatus according to claim 1, further comprising a second resistor connected between the plurality of capacitors and the output terminal.