JPH022953A - Ic testing apparatus - Google Patents

Abstract

PURPOSE:To make it possible to remove the charging and discharging current values of a smoothing capacitor by providing first and second current measuring devices, a simulating circuit and an operating means. CONSTITUTION:A voltage source 200 applies a specified power source voltage to an IC under test 100. A first current measuring device 300 measures a current flowing through the IC under test 100 from the voltage source 200. A smoothing capacity 600 smoothes the pulsation of the applied voltage which is generated by the operation of the IC under test 100. When a voltage is applied to the power source terminals of the IC under test 100 under the state wherein the operation of the IC under test is stopped, a current that is equivalent to the charging and discharging current flowing through the smoothing capacitor 600 is generated in an artificial circuit 700. A second current measuring circuit 800 measures the charging and discharging currents generated in the artificial circuit 700. In an operating means 900, the measured result in the second current measuring device 800 is subtracted from the measured result of the first current measuring device 300. Thus the current value flowing through the IC under test 100 is obtained.

Description

Translated fromJapanese

【発明の詳細な説明】「産業上の利用分野」この発明はＣＭＯ５のように定常時に流れる電流が応動
時に流れる電流と比較して極めて小さいＩＣを試験する
ＩＣ試験装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an IC testing device for testing an IC, such as a CMO5, in which the current flowing during steady state is extremely small compared to the current flowing during response.

「従来の技術」第２図に従来の１ｃ試験装置の回路構造を示す。"Conventional technology"FIG. 2 shows the circuit structure of a conventional 1c test device.

このＩＣ試験装置は被試験ＩＣ１００の直流特性を試験
する試験装置であって、電圧源２００から既知の直流電
圧ｖｉを被試験ＩＣ１００の電源端子に印加すると共に
電流測定回路３００で被試験ＩＣ１００に流れる電流Ｉ
Ｌに相当する電流■８を測定する回路構造となっている
。This IC test device is a test device that tests the DC characteristics of the IC under test 100, and applies a known DC voltage vi from a voltage source 200 to the power supply terminal of the IC under test 100, and a current measurement circuit 300 flows to the IC under test 100. current I
The circuit structure is to measure the current 8 corresponding to L.

尚、電流測定装置３００は電圧源２００と被試験ＩＣ１
００の間に直列接続した電流検出用抵抗器ＲＭと、この
抵抗器ＲＭに発生する電圧を取出す差動増幅器３０１と
、ＡＤ変換器３０２とによって構成することができる。Note that the current measuring device 300 includes a voltage source 200 and an IC under test 1.
00, a current detection resistor RM connected in series between the resistors RM, a differential amplifier 301 that extracts the voltage generated in the resistor RM, and an AD converter 302.

また４００は被試験ＩＣ１００に印加される電圧ｖｓを
電圧源２００を構成する演算増幅器２０１に帰還し、基
準電圧源２０２から与えた入力電圧Ｖｔが被試験ＩＣ１
００に正しく印加されるように演算増幅器２０１を動作
させるための帰還回路、５００はガードアンプを示す。Further, 400 feeds back the voltage vs applied to the IC under test 100 to the operational amplifier 201 constituting the voltage source 200, and input voltage Vt applied from the reference voltage source 202 to the IC under test 100.
A feedback circuit 500 is a guard amplifier for operating the operational amplifier 201 so that the voltage is correctly applied to 00.

このガードアンプ５００は帰還回路４００で取出した被
試験ＩＣ１００の印加電圧ｖ５をガードアンプ５００に
与え、ガードアンプ５００の出力によって帰還回路４０
０の入力線４０１として用いたケーブルの外部導体５０
１の電位を人力線４０１の電位と等しくなるように駆動
し、これによってケーブルの浮遊容量、絶縁抵抗等の影
響を除去して正しい印加電圧ｖ１を電圧源２００に帰還
させるために設けられている。This guard amplifier 500 applies the applied voltage v5 of the IC under test 100 extracted by the feedback circuit 400 to the guard amplifier 500, and uses the output of the guard amplifier 500 to
The outer conductor 50 of the cable used as the input line 401 of 0
1 to be equal to the potential of the human power line 401, thereby eliminating the effects of cable stray capacitance, insulation resistance, etc., and returning the correct applied voltage v1 to the voltage source 200. .

また被試験ＩＣ１００には並列に平滑コンデンサ６００
が接続され、被試験ＩＣ１００が動作することによって
発生する印加電圧の変動を平滑化している。In addition, a smoothing capacitor 600 is connected in parallel to the IC under test 100.
is connected to smooth the fluctuations in the applied voltage caused by the operation of the IC 100 under test.

つまり被試験１ｃ１００がｃｎｏｓ型のＩＣである場合
には、静止時の電流は微少であるにもかかわらず駆動時
の電流は静止時の数１０００倍程度流れる。In other words, when the IC to be tested 1c100 is a CNOS type IC, although the current at rest is very small, the current at the time of driving is about several thousand times that at rest.

例えばクロックの周期で書込、続出を行なうＣＭＯ５型
Ｏ５リの場合にはクロックの周期で過渡的に電流を消費
することになる。For example, in the case of a CMO5 type O5 library that performs writing and successive output at the clock cycle, current is consumed transiently at the clock cycle.

このようにパルス波状に電流を消費する被試験ＩＣ１０
０の動作中の直流特性（電源の印加電圧対消費電流の変
化特性）を測定するために、被試験ＩＣ１００を接続す
る部分（一般にテストヘッドと呼ぶ）に平滑コンデンサ
６００を接続し、被試験ＩＣ１００がパルス波状に電流
を消費するとき、平滑コンデンサ６００に蓄えた電荷を
放出し、過渡的に電圧が低下することを阻止し、平滑化
するようにしている。The IC under test 10 consumes current in a pulse wave like this.
In order to measure the DC characteristics (change characteristics of the applied voltage vs. current consumption of the power supply) during operation of the IC 100, a smoothing capacitor 600 is connected to the part (generally called a test head) to which the IC 100 under test is connected. When the current is consumed in a pulse waveform, the charge stored in the smoothing capacitor 600 is released to prevent the voltage from decreasing transiently and to smooth the voltage.

「発明が解決しようとする課題」ところで平滑コンデンサ６００は被試験ＩＣ１００を動
作させながら電圧印加電流測定を行なう。いわゆるファ
ンクション試験を行なう場合に有効であるが、被試験Ｉ
Ｃ１００を静止させた状態で電源電圧を印加し、このと
き流れる電流を測定し、この電流が許容範囲に入ってい
るか否かを見るスタテック試験を行なう場合には邪魔な
存在となる。"Problems to be Solved by the Invention" By the way, the smoothing capacitor 600 measures voltage and current while operating the IC 100 under test. It is effective when performing so-called functional tests, but
It becomes a nuisance when performing a static test in which a power supply voltage is applied with the C100 stationary, the current flowing at this time is measured, and whether or not this current is within an allowable range is performed.

つまり被試験ＩＣ１００を動作させずに電源端子に規定
の電源電圧を与え、このとき流れる電流が規定の範囲に
入っているか否かを見るスタテック試験がある。このス
タテック試験を行なう場合、電圧源２００から第３図Ａ
に示すように電圧Ｖ！を与えたとき、電流測定装置３０
０を流れる電流１１は被試験ＩＣ１００に流れる電流Ｉ
Ｌに平滑コンデンサ６００に流れる充電電流ｔｃｔが重
畳して流れる。スタテック試験では被試験ＩＣ１００に
流れる電流■、を測定することが目的であるため平滑コ
ンデンサ６００の充放電電流ＩＣＬがゼロに戻るのを待
って電流！、の値を良否判定装置（特に図示しない）は
ＡＤ変換器３０２から読み取ることになる。In other words, there is a static test in which a specified power supply voltage is applied to the power supply terminal without operating the IC 100 under test, and it is checked whether the current flowing at this time is within a specified range. When performing this static test, from the voltage source 200 to
As shown in the voltage V! When given, the current measuring device 30
The current 11 flowing through 0 is the current I flowing through the IC 100 under test.
A charging current tct flowing through the smoothing capacitor 600 flows in a superimposed manner on L. Since the purpose of the static test is to measure the current flowing through the IC 100 under test, wait until the charging/discharging current ICL of the smoothing capacitor 600 returns to zero and then measure the current! A quality determination device (not particularly shown) reads the values of , from the AD converter 302.

ここで、［コンデンサに直流電圧を印加したとき流れる
電流は、次式で表され、時間の経過と共に凍少し、十分
な時間が経過した後は一定値に達する。Here, the current that flows when a DC voltage is applied to a capacitor is expressed by the following equation, freezes over time, and reaches a constant value after a sufficient amount of time has passed.

Ｉ：全電流、■：印加電圧、Ｒ：等価直列抵抗。I: total current, ■: applied voltage, R: equivalent series resistance.

Ｃ：静電容量、Ｑ、二分極電荷、Ｔ：絶縁抵抗第２項は
吸収電流と呼ばれ、誘電体の種類と印加した電解強度に
依存する０通常は緩和時間が非常に長（、絶縁抵抗によ
る第３項を正確に測定することがむずかしいため実用的
な見地から１〜２分後の全電流値と印加電圧の比を絶縁
抵抗と定義している。Ｊ　（オーム社発行、電子端＠￥
Ｒ通信ハンドブック、第１分冊、５１６頁より）。C: Capacitance, Q: Bipolar charge, T: Insulation resistance The second term is called absorption current and depends on the type of dielectric and the applied field strength. Usually the relaxation time is very long (, Since it is difficult to accurately measure the third term due to resistance, from a practical standpoint, insulation resistance is defined as the ratio of the total current value after 1 to 2 minutes and the applied voltage. @￥
R Communication Handbook, Volume 1, page 516).

このようにコンデンサに流れる充放電電流が安定するま
での時間は長いため被試験＋ｃｔｏｏに流れる電流ＩＬ
を正確に測定しようとすると、待ち時間が長くなり、試
験に要する時間が長くなって多くのＩＣを試験する場合
にこれが障害となっている。In this way, it takes a long time for the charging/discharging current flowing through the capacitor to stabilize, so the current IL flowing through the tested +ctoo
Accurately measuring the IC results in long waiting times and longer test times, which is an obstacle when testing large numbers of ICs.

「課題を解決するための手段」この発明では被試験ＩＣに流れる電流を測定する第１電
流測定装置を具備し、被試験ＩＣの電圧印加電流特性を
試験するＩＣ試験装置において、被試験ＩＣの電源端子
に電圧を印加したとき平滑コンデンサに流れる充放電電
流と等価な充放電電流を発生させる擬似回路と、この擬似回路で発生する充放電電流を測定する第２電流
測定装置と、第１＄ｉ流測定装置を第２電流測定装置の測定結果を減
算し被試験ＩＣに流れる電流値を求める演算手段と、を付加した構造としたものである。"Means for Solving the Problems" The present invention provides an IC testing apparatus that includes a first current measuring device that measures the current flowing through the IC under test, and that tests the voltage applied current characteristics of the IC under test. a pseudo-circuit that generates a charging/discharging current equivalent to the charging/discharging current flowing through a smoothing capacitor when a voltage is applied to a power supply terminal; a second current measuring device that measures the charging/discharging current generated in the pseudo-circuit; The i-current measuring device has a structure in which the following is added: arithmetic means for subtracting the measurement result of the second current measuring device to obtain the value of the current flowing through the IC under test.

「作　用」この発明の構成によれば平滑コンデンサに流れる充放電
電流と等価７Ｊ、流を発生する擬似回路を設け、この擬
似回路で発生する充放電電流を第２電流測定装置で測定
し、この測定値を第１電流測定装置の測定値から減算す
ることにより第１電流測定装置で測定した電流値から平
滑コンデンサに流れる充放電電流の値を、除去すること
ができ、よって平滑コンデンサの充放電電流が流れてい
る期間でも被試練ＩＣを流れる電流値を正確に求めるこ
とができる。"Function" According to the configuration of the present invention, a pseudo circuit is provided that generates a charge/discharge current of 7 J equivalent to the charge/discharge current flowing through the smoothing capacitor, and the charge/discharge current generated in this pseudo circuit is measured by a second current measuring device. By subtracting this measured value from the measured value of the first current measuring device, the value of the charging/discharging current flowing to the smoothing capacitor can be removed from the current value measured by the first current measuring device. Even during the period when the discharge current is flowing, the value of the current flowing through the IC under test can be accurately determined.

「実施例」第１図にこの発明の一実施例を示す。"Example"FIG. 1 shows an embodiment of the present invention.

第１図において、第２図と対応する部分には同一符号を
付して示す。In FIG. 1, parts corresponding to those in FIG. 2 are designated by the same reference numerals.

つまり電圧源２００から第１電流測定装置３００を通じ
て被試ＭＩＣ１００に所望の電圧を印加する点、被試験ＩＣ１００に並列に平滑コンデンサ６００を接続
している点、被試験ＩＣ１００に印加される電圧■８を帰還回路４０
０を通じて電圧源２００に帰還し、印加電圧■、が入力
電圧Ｖ、と等しくなるように制御する点、帰還回路４００で取出した印加電圧ｖｓをガードアンプ
５００に人力し、ガードアンプ５００によって帰還回路
４００の入力線４０１を構成する同軸ケーブルの外部導
体の電位を入力線４０１と同一電位に保ち、同軸ケーブ
ルの浮遊容量、ｋＩＡ縁抵抗抵抗響を除去する点は第２
図で説明した従来のものと同じである。In other words, a desired voltage is applied from the voltage source 200 to the MIC 100 under test through the first current measuring device 300, a smoothing capacitor 600 is connected in parallel to the IC 100 under test, and the voltage applied to the IC 100 under test 8 The feedback circuit 40
0 to the voltage source 200 and is controlled so that the applied voltage V is equal to the input voltage V. The applied voltage V taken out by the feedback circuit 400 is input to the guard amplifier 500, and the guard amplifier 500 inputs the feedback circuit. The second point is to keep the potential of the outer conductor of the coaxial cable constituting the input line 401 at the same potential as the input line 401 to eliminate the stray capacitance of the coaxial cable and the kIA edge resistance.
This is the same as the conventional one explained in the figure.

この発明の特徴とする点は、電圧ｍ２ｏｏから被試験Ｉ
Ｃ１００に所定の電源電圧を与えたとき、平滑コンデン
サ６００に流れる充放電電流［ＣＬと等価な充放電電流
１’　ＣＬを発生する擬似回路７００を設けた点と、こ
のＩＭ偵回路７００に発生する充放電Ｔｊ、’１Ｍ　ｌ
’。を測定する第２電流測定装置８００を設けた点であ
る。The feature of this invention is that from the voltage m2oo to the I
When a predetermined power supply voltage is applied to C100, the charging/discharging current flowing through the smoothing capacitor 600 [CL is equivalent to the charging/discharging current 1' CL is provided. Charge/discharge Tj, '1M l
'. The point is that a second current measuring device 800 is provided to measure the current.

擬似回路７００は例えば同軸ケーブルの外部導体５０ｉ
に平滑コンデンサ６００と同じコンデンサ７０１を接続
して構成することができる。The pseudo circuit 700 is, for example, an outer conductor 50i of a coaxial cable.
The same capacitor 701 as the smoothing capacitor 600 can be connected to the smoothing capacitor 600.

第２電流測定装置８００は第１電流測定装置３００と同
様にガートアンプ５００の出力側に直列接続した電流検
出用抵抗器ＲＮと、この電流検出用抵抗器Ｒ１１′に発
生する電圧を取出す差動増幅器８０１とによって構成す
ることができる。Like the first current measuring device 300, the second current measuring device 800 includes a current detecting resistor RN connected in series to the output side of the Gart amplifier 500, and a differential current detecting resistor RN that extracts the voltage generated across the current detecting resistor R11'. It can be configured with an amplifier 801.

第１電流測定装置３００と第２電流測定装置８００の測
定出力信号は減算手段９００を構成する差動増幅器に与
え被測定ＩＣ１００に流れる電流■、と平滑コンデンサ
６００の充電電流ｔｃｔの和の電流ＩＬ＋ＩＣＬから擬
似回路７００に流れる電流Ｉ′６．を減算する。The measurement output signals of the first current measuring device 300 and the second current measuring device 800 are applied to the differential amplifier constituting the subtracting means 900, and the current IL+ICL is the sum of the current flowing through the IC 100 under test 100 and the charging current tct of the smoothing capacitor 600. A current I'6. flows into the pseudo circuit 700 from I'6. Subtract.

擬似回路７００に用いたコンデンサ７０１を平滑コンデ
ンサ６００と同じ容量で然も同一素材で作られたコンデ
ンサを用いることにより擬似回路７００で発生する充放
電電流は平滑コンデンサ６００の充放電電流と同等とす
ることができる。By using a capacitor 701 used in the pseudo circuit 700 that has the same capacity as the smoothing capacitor 600 and is made of the same material, the charging and discharging current generated in the pseudo circuit 700 is made equal to the charging and discharging current of the smoothing capacitor 600. be able to.

この結果減算手段９００から出力される信号は被試験Ｉ
Ｃ１００に流れる電流■１と等価となる。As a result, the signal output from the subtraction means 900 is
This is equivalent to the current ■1 flowing through C100.

減算手段９００の出力はＡＤ変換器３０２でへ〇変換し
て送り出すことにより、例えばコンピュータから成る判
定装置に取込まれ、比較判定されて良否の判定が行なわ
れる。The output of the subtracting means 900 is converted into 0 by an AD converter 302 and sent out, and is taken into a determination device consisting of, for example, a computer, where it is compared and determined to determine whether it is good or bad.

「発明の効果」以上説明したように、この発明によれば擬似回路７００
で平滑コンデンサ６００に流れる充放電電流と等価な電
流を発生させ、この充放電電流の値を第１″ｉ１を流測
定装置の測定結果から減算することにより、平滑コンデ
ンサ６００の充放電電流値を除去することができる。"Effects of the Invention" As explained above, according to the present invention, the pseudo circuit 700
By generating a current equivalent to the charging/discharging current flowing through the smoothing capacitor 600 and subtracting the value of this charging/discharging current from the measurement result of the current measuring device, the charging/discharging current value of the smoothing capacitor 600 can be calculated. Can be removed.

よって平滑コンデンサ６００に充放電電流が流れている
期間でも被試験ＩＣ１００に流れる電流■、を正確に求
めることができ、この結果被試験ＩＣ１００に電源電圧
を印加した直後に被試験ＩＣ１００に流れる電流ＩＬを
測定することができ、試験に要する時間を短かくするこ
とができる。Therefore, even during the period when the charging/discharging current is flowing through the smoothing capacitor 600, it is possible to accurately determine the current flowing through the IC 100 under test 100, and as a result, the current IL flowing through the IC 100 under test immediately after the power supply voltage is applied to the IC 100 under test. can be measured, and the time required for testing can be shortened.

「変形実施例」上述では擬似回路７００をガードアンプ５００で駆動す
る構造を説明したが、必ずしもガードアンプ５００を用
いる必要はなく、ガードアンプ５００とは別に擬似回路
７００を駆動する専用のバッファアンプを設けてもよい
。“Modified Embodiment” In the above, a structure in which the pseudo circuit 700 is driven by the guard amplifier 500 has been described, but it is not necessarily necessary to use the guard amplifier 500. It may be provided.

また上述では擬似回路７００を構成するコンデンサ７０
１を平滑コンデンサ６００の容量と同一に選定した場合
を説明したが、第２電流測定回路８００の出力側に利得
調整回路を挿入すればコンデンサ７０１の容量と平滑コ
ンデンサ６００の容量は必ずしも一致させる必要はない
。Furthermore, in the above description, the capacitor 70 constituting the pseudo circuit 700
1 is selected to be the same as the capacitance of the smoothing capacitor 600, but if a gain adjustment circuit is inserted on the output side of the second current measurement circuit 800, the capacitance of the capacitor 701 and the capacitance of the smoothing capacitor 600 do not necessarily have to match. There isn't.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は′この発明の一実施例を説明するための接続図
、第２図は従来の技術を説明するための接続図、第３図
は従来の技術の動作を説明するための波形図である。１００・・・被試験ＩＣ，２００・・・電圧源、３００
・・・第１電流測定装置、４００・・・帰還回路、５０
０・・・ガードアンプ、６００・・・平滑コンデンサ、
７００・・・擬似回路、８００・・・第２電流測定装置
、９００・・・演算手段。Fig. 1 is a connection diagram for explaining an embodiment of the present invention, Fig. 2 is a connection diagram for explaining the conventional technique, and Fig. 3 is a waveform diagram for explaining the operation of the conventional technique. It is. 100... IC under test, 200... Voltage source, 300
...first current measuring device, 400...feedback circuit, 50
0...guard amplifier, 600...smoothing capacitor,
700... Pseudo circuit, 800... Second current measuring device, 900... Arithmetic means.

Claims (1)

Translated fromJapanese

【特許請求の範囲】[Claims]（１）Ａ、被試験ＩＣに所定の電源電圧を印加する電圧
源と、Ｂ、この電圧源から上記被試験ＩＣに流れる電流を測定
する第１電流測定装置と、Ｃ、上記被試験ＩＣが動作することによって発生する上
記被試験ＩＣに印加される電圧の脈動を平滑化する平滑
コンデンサと、Ｄ、被試験ＩＣの動作を停止させた状態で被試験ＩＣの
電源端子に電圧を印加したとき上記平滑コンデンサに流
れる充放電電流と等価な電流を発生させる擬似回路と、Ｅ、この擬似回路で発生する充放電電流を測定する第２
電流測定装置と、Ｆ、上記第１電流測定装置とこの第２電流測定装置の測
定結果を減算し上記被試験ＩＣに流れる電流値を求める
演算手段と、から成るＩＣ試験装置。(1) A: a voltage source that applies a predetermined power supply voltage to the IC under test; B: a first current measuring device that measures the current flowing from this voltage source to the IC under test; and C: the IC under test. A smoothing capacitor that smoothes the pulsations in the voltage applied to the IC under test that occurs when the IC under test operates, and D. When voltage is applied to the power supply terminal of the IC under test with the IC under test stopped operating. A pseudo-circuit that generates a current equivalent to the charging/discharging current flowing through the smoothing capacitor, and E, a second circuit that measures the charging/discharging current generated in this pseudo-circuit.
An IC testing device comprising: a current measuring device; and F. calculating means for subtracting the measurement results of the first current measuring device and the second current measuring device to obtain a current value flowing through the IC under test.