JP3558080B2 - Method of correcting measurement error, method of determining quality of electronic component, and electronic component characteristic measuring device - Google Patents

Description

ここで、測定装置１，２が測定するインピーダンスＺ_Ｍは、次の（２），（２’）式により求められる。
Ｚ_Ｍ＝Ｖ_Ｍ／Ｉ_Ｍ …（２）
Ｚ_Ａ＝Ｖ_Ａ／Ｉ_Ａ …（２’）
上記（２），（２’）式を（１）式に代入することにより、次の（３）式が得られる。
Ｚ_Ａ＝（Ｄ・Ｚ_Ｍ−Ｂ）／（Ｃ・Ｚ_Ｍ−Ａ） …（３）
上記（３）式におけるＺ_Ａは被検体試料のインピーダンス真値を示している。上記（３）式は有理式であり、誤差要因を構成する４つの未知数Ａ，Ｂ，Ｃ，Ｄ（以下、これら未知数を誤差項Ａ〜Ｄという）のうち一つは明らかに自由に選択することができる。そのため、例えば、誤差項Ｄ＝１とおいたうえで、残りの３つの誤差項Ａ，Ｂ，Ｃを決定することにより、測定装置１，２が観測するインピーダンスＺ_Ｍから被検体試料のインピーダンス真値Ｚ_Ａを決定することができる。
【００５２】
しかしながら、被検体試料が非同軸形状を有する場合、１ＭＨｚ〜数ＧＨｚ程度の高周波帯域におけるインピーダンスが既知である標準器（標準器として機能する電子部品）を作製することは、現状ではほとんど不可能である。
【００５３】
そこで、本実施形態では、次のようにして被検体試料の実測測定装置の測定値を補正して被検体試料の基準測定装置における測定値を精度高く推定している。ここで、まず、測定の誤差要因Ｆ_１を決定する誤差項Ａ_１，Ｂ_１，Ｃ_１，Ｄ_１が同定された基準測定装置１があり、この基準測定装置１によって補正データ取得試料１１Ｂのインピーダンス測定値Ｚ_Ｍ１が測定されたと仮定する。
【００５４】
この場合、補正データ取得試料１１Ｂのインピーダンス真値Ｚ_Ａは、基準測定装置１によるインピーダンス測定値Ｚ_Ｍ１から、次の理論数式（４）により求められる。
Ｚ_Ａ＝（Ｄ_１・Ｚ_Ｍ１−Ｂ_１）／（Ｃ_１・Ｚ_Ｍ１−Ａ_１） …（４）
同様に、測定の誤差要因Ｆ_２を決定する誤差項Ａ_２，Ｂ_２，Ｃ_２，Ｄ_２が同定された実測測定装置２があり、この実測測定装置２によって補正データ取得試料１１Ｂのインピーダンス測定値Ｚ_Ｍ２が測定されたと仮定する。
【００５５】
この場合、補正データ取得試料１１Ｂのインピーダンス真値Ｚ_Ａは、実測測定装置２によるインピーダンス測定値Ｚ_Ｍ２から、次の理論数式（５）式により求められる。
Ｚ_Ａ＝（Ｄ_２・Ｚ_Ｍ２−Ｂ_２）／（Ｃ_２・Ｚ_Ｍ２−Ａ_２） …（５）
ここで、測定系は異なっていても、同じ補正データ取得試料１１Ｂを測定しているのであるからインピーダンス真値Ｚ_Ａは等しい。したがって、理論数式（４）と理論数式（５）の右辺同士は等しいことになる。そのため、次の（６）式が成立する。
【００５６】

さらに、上記（６）式を整理することによりの、次の（７）式が得られる。
【００５７】

上記（７）式において、右辺の分子・分母を（Ａ_１・Ｄ_２−Ｂ_１・Ｃ_２）で除したうえで適当な変数変換を行うことにより、未定係数が３個の次の（８）式が得られる。（８）式が本発明におけるインピーダンス測定の相対補正式である。
Ｚ_Ｍ１＝（Ｚ_Ｍ２＋α）／（β・Ｚ_Ｍ２＋γ） …（８）
上記相互関係式（８）において未定係数α，β，γが同定できれば、実測測定装置２の測定結果Ｚ_Ｍ２から基準測定装置１による測定結果Ｚ_Ｍ１を精度高く推定することができる。
【００５８】
なお、仮に基準測定装置１が全く誤差要因Ｆのない完璧な測定装置であったとすると、このような理想的な基準測定装置１と実測測定装置２との間の相対補正を行うことになる。このような相対補正は、１ポート測定系の誤差除去式である上記（７）と一致するはずである。
【００５９】
実際、基準測定装置１を誤差要因Ｆのない完璧な装置とみなす場合、上記相互関係式（８）において、係数Ａ_１＝１，Ｂ_１＝０，Ｃ_１＝０，Ｄ_１＝１となる。そうすると、上記相互関係式（８）により得られるインピーダンス測定値Ｚ_Ｍ１の値は、上記（７）式により得られるインピーダンス測定値Ｚ_Ｍ１の値に一致する。
【００６０】
上記相互関係（８）においては、未定係数がα，β，γの３個含まれており、Ｚ_Ｍ１およびＺ_Ｍ２の二つの変数は測定により得られる値である。そのため、補正データ取得試料１１Ｂとして、３個の試料を準備したうえで、これらの補正データ取得試料１１Ｂのインピーダンスを基準測定装置１と実測測定装置２とで測定すれば、未定係数α，β，γを同定することができる。つまり、この誤差補正方法を用いれば、補正データ取得試料１１Ｂのインピーダンス真値や測定装置１，２が有する誤差項Ａ_１，Ｂ_１，Ｃ_１，Ｄ_１，Ａ_２，Ｂ_２，Ｃ_２，Ｄ_２等は全く未知のままでも未定係数α，β，γを同定することができる。
【００６１】
相互関係式（８）において３つの補正データ取得試料１１Ｂのインピーダンス測定値を代入したうえで整理することで、次の相互関係式（９）が得られる。
【００６２】
【数２】

なお、（８），（９）に示した本発明における相互関係式は、基準測定装置１の測定値真値と実測測定装置２の測定値真値との間の関係を一義的に示す関係式である。ここでいう一義的とは両真値がほぼ正確に一致することをいう。また、ここいうほぼ正確とは、図９を参照して後述するように、補正誤差±０．８％以内に収まる程度の補正精度を示す。
【００６３】
相互関係式（９）式中において、Ｚ_{Ｍ２（１）}，Ｚ_{Ｍ２（２）}，Ｚ_{Ｍ１（１）}等に示されるように、下付文字_{Ｍ１，Ｍ２}の末尾に付与されている数字_{（１），（２），（３）}は、その数字の番号を付与された補正データ取得試料１１Ｂ_{１ 〜 ３}のインピーダンス測定値であることを示している。
【００６４】
なお、以上説明した補正方法においては、未定係数α，β，γを、３個の補正データ取得試料１１Ｂ_{１ 〜 ３}のインピーダンス測定値Ｚ_{Ｍ２（１） 〜 Ｍ２（３）}から３元１次連立方程式の解として算出している。しかしながら、４個以上の補正データ取得試料１１Ｂ_{１ 〜 ｎ}についてインピーダンス測定値Ｚ_{Ｍ２（１） 〜 Ｍ２（ｎ）}を測定したうえで、最小自乗法などの最尤法を用いてこれら未定係数α，β，γを同定してもよい。そうすれば、補正データ取得試料１１Ｂの測定時において生じる測定誤差の影響を低減することができる。
【００６５】
また、上述した相互関係式（９）は３次の行列式であって数学的には非常に簡単な構成であるものの、作業者による手計算で解を得るには手間がかかる。そのため、計算機を用いた自動計算において汎用されているアルゴリズム，例えば、ＬＵ分解法などを用いて上述した相互関係式（９）を計算すれば計算の自動化を図ることができる。
【００６６】
次に、本発明のインピーダンス補正方法により補正した結果を説明する。図７は補正を実施したシステムの構成を示している。このシステムにおいて、基準測定装置１と実測測定装置２とは、インピーダンスアナライザ１００と、基準測定治具１０１と、実測測定治具１０２とを備えている。
【００６７】
インピーダンスアナライザ１００は４２９１Ａ（アジレント・テクノロジー製）から構成されている。インピーダンスアナライザ１００はテストヘッド１００ａを有している。テストヘッド１００ａは校正面１００ｂを有しており、この校正面１００ｂにＡＰＣ７（７ｍｍ直径のコネクタ）−ＳＭＡ（３．５ｍｍ直径のコネクタ）変換アダプタ１０３が取り付けられている。基準測定治具１０１と実測測定治具１０２とはＳＭＡコネクタ１０４を備えており、このコネクタ１０４をアダプタ１０３に装着することで、治具１０１，１０２はテストヘッド１００ａの校正面１００ｂに取り付け可能となっている。
【００６８】
ただし、実測測定治具１０２は、３ｄＢの減衰器（ＭＫＴ：タイセー社製）１０５と１．５ｍのセミフレキシブル同軸ケーブル（ＦＬＥＸＣＯ社製）１０６とを介してアダプタ１０３に取り付けられている。減衰器１０５と同軸ケーブル１０６とを介在させるのは、実測測定治具１０２に搭載する測定対象電子部品１１Ａが有するインピーダンスに通常発生するよりも大きな誤差を付与するためである。これにより、本発明の補正方法の精度の高さを分かりやすくすることができる。
【００６９】
なお、この構成においては、ＡＰＣ７−ＳＭＡ変換アダプタ１０３は、図１における同軸ケーブルコネクタ６を構成し、ＳＭＡコネクタ１０４は図２における同軸コネクタ９を構成し、基準測定治具１０１は基準測定治具５Ａを構成し、実測測定治具１０２は実測測定治具５Ｂを構成する。
【００７０】
以上のシステムにおいては、インピーダンスアナライザ１００に基準測定治具１０１を装着すれば、基準測定装置１と見なすことができる。また、インピーダンスアナライザ１００に実測測定治具１０２を装着すれば、実測測定装置２と見なすことができる。
【００７１】
以上説明したシステムにおいて、開放，短絡，終端の各補正データ取得試料１１Ｂ_{１ 〜 ３}を基準測定治具１０１，実測測定治具１０２に実装する。そして、各治具１０１，１０２それぞれをテストヘッド１００ａに接続することでインピーダンスを測定する。さらには、測定により得られたインピーダンス測定値を前述した相互関係式（９）に代入することで、未定係数α，β，γを同定する。なお、インピーダンスの測定は、１ＭＨｚ〜１００ＮＨｚの周波数範囲，ポイント数２０１点で実施する。
【００７２】
次に、キャパシタ，インダクタ，１００Ω抵抗，３３０Ω抵抗からなる測定対象電子部品１１Ａ_{１ 〜 ４}を用意し、これら測定対象電子部品１１Ａ_{１ 〜 ４}を実測測定治具１０２に実装する。そして、実測測定治具１０２をテストヘッド１００ａに接続することで、測定対象電子部品１１Ａ_{１ 〜 ４}のインピーダンスをインピーダンスアナライザ１００で測定する。
【００７３】
得られたインピーダンス測定値Ｚ_{Ｍ２（１） 〜 Ｍ２（４）}（実測測定装置２の測定値に相当する）を、先に未定係数α，β，γを同定しておいた相互関係式（８），（９）式に代入することで、基準測定装置１の測定値Ｚ_{Ｍ１（１） 〜 Ｍ１（４）}を推定する。
【００７４】
次に、測定対象電子部品１１Ａ_{１ 〜 ４}を基準測定治具１０１に実装する。そして、基準測定治具１０１をテストヘッド１００ａに接続することで、測定対象電子部品１１Ａ_{１ 〜 ４}のインピーダンスをインピーダンスアナライザ１００で測定する。測定により得られた測定対象電子部品１１Ａ１〜４のインピーダンス測定値（基準測定装置１での測定真値Ｚ_{Ａ１ 〜 ４}に相当する）と、先に推定しておいた基準測定装置１の測定値Ｚ_{Ｍ１（１） 〜 Ｍ１（４）}とを比較する。その比較結果を図８と図９に示す。
【００７５】
図８は、測定結果を示し、図９は１００Ω抵抗と３３０Ω抵抗の測定値の誤差変動を示している。図８において横軸は周波数を示し、縦軸はインピーダンス値を示している。図９において横軸は周波数を示し、縦軸は誤差精度を示している。
また、これらの図において、真Ｌ，真Ｃ，真１００，真３３０は、それぞれ、インダクタ，キャパシタ，１００Ω抵抗，３３０Ω抵抗の基準測定装置１（基準測定治具１００）での測定結果を示している。無Ｌ，無Ｃ，無１００，無３３０は、それぞれ、インダクタ，キャパシタ，１００Ω抵抗，３３０Ω抵抗の実測測定装置２（実測測定治具１０２）での測定結果を示している。相対Ｌ，相対Ｃ，相対１００，相対３３０は、それぞれ、インダクタ，キャパシタ，１００Ω抵抗，３３０Ω抵抗の実測測定装置２（実測測定治具１０２）での補正値を示している。
【００７６】
これらの図から明らかなように、本発明の補正方法を実施することで、±０．８％以内に正確に補正されている。
【００７７】
以下、本実施形態の測定誤差補正方法により補正方法を具体的に説明する。
【００７８】
用意した３個の補正データ取得試料１１Ｂ_{１ 〜 ３}が、基準測定装置１に搭載される。そして、各試料１１Ｂ_{１ 〜 ３}のインピーダンスが各周波数ポイント毎に測定される。 これら基準測定装置１における補正データ取得試料１１Ｂ_{１ 〜 ３}のインピーダンスを測定した結果が、実測測定装置２の図示しないデータ入力部を介して実測測定装置２に予め入力されている。入力された基準測定装置１の測定結果は、制御部本体２２を介してメモリ２３に記憶されている。
【００７９】
一方、実測測定装置２においても、同様に、補正データ取得試料１１Ｂ_{１ 〜 ３}が基準測定装置２に搭載される。そして、補正データ取得試料１１Ｂ_{１ 〜 ３}のインピーダンスが各周波数ポイント毎に測定される。
【００８０】
実測測定装置２による補正データ取得試料１１Ｂ_{１ 〜 ３}のインピーダンス測定結果は、制御部本体２を介して相互関係式算定手段２４に入力される。
【００８１】
相互関係式算定手段２４は、実測測定装置２による補正データ取得試料１１Ｂ_{１ 〜 ３}のインピーダンス測定結果が入力されると、制御部本体２２を介してメモリ２３から、基準測定装置１で測定した補正データ取得試料１１Ｂ_{１ 〜 ３}の測定結果を読み出す。
【００８２】
相互関係式算定手段２４は、基準測定装置１の測定結果と実測測定装置２の測定結果とに基づいて、実測測定装置２による測定結果と基準測定装置１による測定結果との間の相互関係式を算定する。算定は、前述した相互関係式（８），（９）式に基づいて行われる。
【００８３】
以上の準備工程を経たのち、実測測定装置２のインピーダンスアナライザ本体２０により測定対象電気部品１１Ａのインピーダンスが測定される。測定対象電気部品１１Ａの測定結果は、制御部本体２２を介して補正手段２５に入力される。
【００８４】
補正手段２５は、測定対象電気部品１１Ａの測定結果が入力されると、制御部本体２２を介してメモリ２３から相互関係式を読み出す。補正手段２５は、読み出した相互関係式に測定対象電気部品１１Ａの測定結果であるインピーダンス値を代入して計算する。これにより、補正手段２５は、実測測定装置２における測定対象電気部品１１Ａの測定結果（インピーダンス）を、基準測定装置１により測定した場合に得られると推定されるインピーダンスに補正する。補正手段２５は、算定した補正値（インピーダンス）を制御部本体２２を介して外部に出力する。出力は、図示しない表示部により表示出力してもよいし、図示しないデータ出力部によりデータとして出力してもよい。
【００８５】
なお、このような計算処理は、上述したように、インピーダンスアナライザ３Ｂに内蔵された制御部２１により行ってもよいし、インピーダンスアナライザ３に接続された外部コンピュータに対して測定結果を出力してこの外部コンピュータにより行ってもよい。
【００８６】
以上説明した本実施形態の測定結果の補正方法によれば、次のような効果がある。すなわち、電子部品メーカでその電子部品のインピーダンスを保証する場合においては、メーカ側に設けられた測定装置で測定した結果に基づいて、そのインピーダンスが保証される。しかしながら、その電子部品を購入したユーザ側に設けられた測定装置において、その電子部品のインピーダンスを測定したとしても同等の測定結果が出るとは限らない。そのため、これでは、メーカが保証しているインピーダンスを確認することができず、その保証は再現性がなく不確実なものとなってしまう。
【００８７】
これに対して、メーカ側の測定装置を基準測定装置１とし、ユーザ側の測定装置２を実測測定装置としたうえで本実施形態の測定誤差の補正方法を実施すれば、メーカ側の測定結果と同等であると推定されるインピーダンスを、ユーザ側の実測測定装置２における測定結果に基づいてユーザ側で算出することができる。これにより、メーカ側の実施する電子部品の保証を再現することができて、十分に確実なものとなり、したがって、ユーザに受け入れられることが可能となる。
【００８８】
しかも、実測測定装置２の状態を厳密に検査管理する（例えば、実測測定装置２の実測測定治具５Ｂの特性を、基準測定装置１の基準測定治具５Ａの特性と同等となるように調整管理する）ことなく上記補正が行えるので、その分、測定に要するコストを抑えることができる。
【００８９】
さらには、メーカ側においては、量産工程中に多数設置される自動測定選別機を前記実測測定装置として選定することも可能になるので、その分、さらに測定に要するコスト（この場合には不良部品選別コスト）を抑えることができるうえに測定時間の短縮化を図ることができる。
【００９０】
しかも、測定治具５Ａ，５Ｂに起因する測定誤差の補正のみならず、実測測定装置２全体の測定誤差を同時に補正することができるので、実測測定装置２において特別なキャリブレーションを実施する必要もなくなり、その分、さらに測定コストを抑えることができる。
【００９１】
さらには、本実施形態の測定装置では、自動測定選別機に対する組み込み性能や長寿命化を測定特性の安定化より優先させた実測測定治具５Ｂを用いても、その測定結果に何ら影響は出ない。そのため、その分、さらに測定に有するコストを抑えることができるうえに、測定時間の短縮化を図ることができる。
【００９２】
【発明の効果】
以上説明したように、本発明によれば、基準測定装置に対して測定結果が完全に一致しない実測測定の測定結果を、基準測定装置の測定結果と同等に補正することができる。
【図面の簡単な説明】
【図１】本発明の測定誤差の補正方法を実施する測定装置の概略構成を示す平面図である。
【図２】本発明の測定誤差の補正方法を実施する測定装置を構成する測定治具の構成を示す平面図である。
【図３】本発明の測定誤差の補正方法を実施する測定装置の構成を示すブロック図である
【図４】本発明の測定誤差の補正方法を実施する測定装置を構成する補正データ取得試料および測定対象電気部品の構成を示す裏面図である。
【図５】本発明の測定誤差の補正方法を実施する測定装置を構成する補正データ取得試料の構成を示す平面図である。
【図６】本発明の測定誤差の補正方法を実施する際に用いる信号伝達形態（誤差モデル）の一例である。
【図７】本発明のインピーダンス補正方法による補正したシステムの構成を示す図である。
【図８】本発明の測定誤差の補正方法を実施して得られる補正データならびに測定結果を示す線図である。
【図９】本発明の測定誤差の補正方法を実施して得られる補正データの誤差精度を示す線図である。
【符号の説明】
１ 基準測定装置
２ 実測測定装置
３Ａ，３Ｂ インピーダンスアナライザ
４ 同軸ケーブル
５Ａ，５Ｂ 測定治具
６ 同軸ケーブルコネクタ
７ 絶縁基板
８ａ 信号伝送路
８ｂ，８ｃ 接地線路
９ 同軸コネクタ
１０ スルーホール接続部
１１Ａ 測定対象電子部品
１１Ｂ 補正データ取得試料
１２ａ 伝送路端子
１２ｂ，１２ｃ 接地端子
１３ 枠体
１４ａ 擬似伝送路端子
１４ｂ，１４ｃ 擬似接地端子
１５ａ〜１５ｃ 実装端子
１６ａ〜１６ｅ インピーダンス調整用素子
２０ インピーダンスアナライザ本体
２１ 制御部
２２ 制御部本体
２３ メモリ
２４ 相互関係式算定手段
２５ 補正手段
１００ インピーダンスアナライザ
１００ａ テストヘッド
１００ｂ 校正面
１０１ 基準測定治具
１０２ 実測測定治具
１０３ ＡＰＣ７−ＳＭＡ変換アダプタ
１０４ ＳＭＡコネクタ
１０５ 減衰器
１０６ 同軸ケーブル[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a method for correcting a measurement error in which the impedance of an electronic component measured by an actual measurement device whose measurement result does not match the reference measurement device is corrected to an impedance estimated to be obtained when measured using the reference measurement device. The present invention relates to a method, a method for judging the quality of an electronic component using the correction method, and an electronic component characteristic measuring device for implementing the correction method.
[0002]
[Prior art]
In measuring the impedance of an electronic component, the same or similar type of electronic component, such as a measuring device installed on the manufacturer side of the electronic component and a measuring device installed on the user side, is measured by a plurality of measuring devices. May be measured.
[0003]
In such a case, since the measurement errors are different from one measurement device to another, the reproducibility of the measurement is low, and the measurement results obtained by different measurement devices for the same or the same type of electronic component are not equal. .
[0004]
In the measurement of impedance in a low frequency range, such a measurement error is relatively small and does not cause much problem. However, when measuring the impedance in a high frequency range of 1 MHz or more and 2 GHz or less, a measurement error between the measuring devices becomes remarkable. Therefore, in order to improve the reproducibility of the measurement in such a frequency band, the measurement value is corrected by the open / short correction method or the open / short / load correction method. Hereinafter, these correction methods will be described. Note that the impedance measurement performed in the following conventional example and an embodiment of the present invention described later is a concept including admittance measurement.
[0005]
The open / short correction method corrects the impedance when the jig is open (open) and the short (short) in order to correct the effects of floating admittance and residual impedance due to the test fixture (hereinafter, jig). And the impedance in each case. Then, based on the impedance value obtained by the measurement, this is a correction method in which the characteristic (impedance) of the subject alone is calculated by calculation.
[0006]
In the open / short / load correction method, after performing the above-described open / short measurement, a load device having a known physical true value is mounted on the jig, and the open / short / load correction method is the same as described above. Perform a short measurement. Then, the characteristic (impedance) of the subject alone is calculated by calculation based on the impedance value obtained by the measurement. This correction method can obtain a correction with higher accuracy than the open / short correction method (for example, see Non-Patent Document 1).
[0007]
[Non-patent document 1]
HP4284A Precision LCR Meter Instruction Manual (December / 33, 1996), p. 6-15 to p. 6-18
[0008]
[Problems to be solved by the invention]
In the above-described conventional open / short correction method, it is necessary to satisfy one of the following two conditions.
[0009]
The first condition is that impedance measurement is performed in an ideal open state or an ideal short state in order to obtain the effects of floating admittance and residual inductance.
[0010]
The second condition is that the impedance of the jig in an open state or a short state is known.
[0011]
However, these conditions cannot be satisfied for the following reasons. That is, since the open state and the short state of the jig are ideal states and cannot be realized, the first condition cannot be actually satisfied.
[0012]
Further, even if the jig is in the open state, floating inductance is generated, and even if the jig is short-circuited, residual inductance is generated. Therefore, in the conventional example described above,
The operator should not move his hand in the vicinity of the jig during the open correction to suppress the fluctuation of the floating admittance;
-A metal plate with high conductivity should be used as a short-circuit plate used as a short-circuit device at the time of short-circuit correction in order to minimize residual impedance.
Notes are described.
[0013]
However, even if these precautions are adhered to faithfully, it is impossible to realize a true open state / a true short state, and therefore, highly accurate correction is impossible.
[0014]
In addition, the open / short / load correction method has the same disadvantages as the open / short correction method. Further, the open / short / load correction method has a disadvantage that a calibration value of a device used for load correction cannot be accurately measured. This will be described below.
[0015]
In the open / short / load correction method, when performing the load correction, a device whose physical true value is known (hereinafter, referred to as a standard device) is required. The prior art describes that an electronic component to be measured (such as a chip capacitor or a chip coil) whose impedance has been measured in advance may be used as a standard device. However, such a correction method can be implemented only when the measurement frequency is sufficiently low and the measurement accuracy can be maintained even if the effects of stray admittance and residual impedance are ignored. Specifically, if the measurement frequency is less than about several MHz, the above-described correction method is effective.
[0016]
On the other hand, with the recent demand for higher frequency signal bands, there is a demand for electronic components to guarantee impedance in a high frequency band of about 1 MHz to several GHz. However, the above-mentioned correction method cannot obtain the correction accuracy required for guaranteeing the impedance in such a high-frequency band. This will be described below.
[0017]
When measuring impedance in a high frequency band of about 1 MHz to several GHz, the influence of floating admittance and residual impedance cannot be ignored. Therefore, it is necessary to accurately grasp the floating admittance and the residual impedance in order to make the correction accuracy at the time of measurement sufficiently high. In order to grasp these floating residual characteristics, it is necessary to accurately measure the impedance of an electronic component used as a standard device.
[0018]
However, in order to perform such high-precision impedance measurement on an electronic component, a jig used when measuring the electronic component must be corrected. Standard equipment is required. As can be seen from the above, it is practically impossible to perform high-precision correction in the high-frequency band of about 1 MHz to several GHz by the open / short / load correction method unless there is an extremely accurate standard. is there.
[0019]
When the object to be measured has a coaxial connector, a standard device in which the physical true value of the impedance is extremely accurately defined is available. However, such a standard can be produced only in an electronic component having a shape attachable to a coaxial connector, and it is substantially impossible to produce such a standard in a general electronic component such as a chip capacitor or a chip coil. Impossible.
[0020]
Accordingly, a main object of the present invention is to provide a correction method capable of correcting a measurement impedance with high accuracy in a high frequency band of about 1 MHz to several GHz.
[0021]
[Means for Solving the Problems]
In order to solve the above-described problem, in the present invention, the impedance of the electronic component to be measured is measured by an actual measurement device whose measurement result does not match the reference measurement device, and the measured value is measured by the reference measurement device. A method of correcting a measurement error to correct the electrical characteristics estimated to be obtained when measured using,
In advance, as a correction data acquisition sample, a step of preparing a correction data acquisition sample that generates an impedance equivalent to the impedance of the electronic component to be measured by a measurement operation,
The step of measuring the impedance of the correction data acquisition sample by the reference measurement device and the actual measurement device, respectively.
Determining a correlation equation between the measurement result by the actual measurement device and the measurement result by the reference measurement device,
By substituting the impedance of the electric component to be measured measured by the actual measuring device into the interrelation formula and calculating the interrelation formula, the impedance of the electric component to be measured was measured by the reference measuring device. Correcting to the impedance estimated to be obtained in the case;
It is characterized by including. Thereby, the following operation is provided.
[0022]
Based on the measurement results using the data acquisition sample for which the impedance has not been identified, an interrelation equation between the actual measurement device and the reference measurement device is determined. Is corrected to the impedance estimated to be obtained when measured by the reference measurement device, so that calibration using an expensive standard device is not required, and an actual measurement jig used for the actual measurement device, etc. Adjustment is not required. Furthermore, since the electrical characteristics are corrected by the theoretical calculation, the reproducibility of the measurement of the impedance of the electronic component can be improved regardless of the shape (coaxial shape / non-coaxial shape) of the electronic component.
[0023]
Note that the present invention proposes an analytical relative correction method as an example of a correction method using the mutual relational expression.
[0024]
The present invention, as a method of obtaining a correlation equation by an analytical relative correction method,
Procedure for assuming the signal transmission form of the two measurement devices at the time of measurement, including a measurement error factor,
A theoretical formula for calculating the true value of the measurement value of the actual measurement device in the signal transmission mode, and a theoretical formula for calculating the true value of the measurement value of the reference measurement device in the signal transmission mode, respectively,
Based on the two theoretical formulas, the correlation formula consisting of a mathematical expression that uniquely indicates the relationship between the true value of the measured value of the reference measuring device and the true value of the measured value of the actual measuring device, including an undetermined coefficient, is created. Steps to
The procedure of measuring the impedance of the correction data acquisition sample by the reference measurement device and the actual measurement device, respectively.
A procedure for identifying the undetermined coefficient by substituting the measured value of the impedance of the correction data acquisition sample measured by the two measurement devices into the correlation equation,
It is characterized by including.
[0025]
The method for correcting a measurement error according to the present invention can be optimally performed in a method for determining the quality of an electronic component. In this case, the quality of the electronic component is determined by measuring the electronic component to be measured, whose impedance is a required characteristic when measured by the reference measurement device, using an actual measurement measurement device whose measurement result does not match the reference measurement device. The pass / fail judgment is made based on the measurement result.
[0026]
In such a determination method, when implementing the present invention, the impedance of the electronic component to be measured measured by the actual measurement device is corrected by the measurement error correction method of the present invention, and the impedance after this correction and The quality of the electronic component to be measured may be determined by comparing the required characteristic. Then, the quality of the electronic component to be measured can be determined with high accuracy.
[0027]
The present invention proposes the following electronic component characteristic measuring device as a measuring device capable of performing the above-described measurement error correction method.
[0028]
This measuring device has a measuring means for measuring the impedance of the electronic component to be measured, but the measuring result does not match the reference measuring device,
A storage unit for storing a measurement result obtained by measuring the electrical characteristics of a correction data acquisition sample that generates an impedance equivalent to the impedance of the electronic component to be measured by the reference measurement device,
Calculation of a correlation equation for calculating a correlation equation between the impedance of the correction data acquisition sample measured by the measurement means and the impedance of the correction data acquisition sample by the reference measurement device stored in the storage means. Means,
When the impedance of the electrical component to be measured is measured by the reference measuring device by substituting the impedance of the electrical component to be measured measured by the measuring means into the interrelation equation and calculating the interrelation equation. Correction means for correcting the impedance to be obtained to
have.
[0029]
The measuring apparatus of the present invention can be specifically configured based on the following analytical relative correction method.
[0030]
That is, the correlation formula calculating means is:
Means for assuming the signal transmission form of the two measuring devices at the time of measurement, including a measurement error factor,
A theoretical formula for calculating the true value of the measurement value of the actual measurement device in the signal transmission mode, and a theoretical formula for calculating the true value of the measurement value of the reference measurement device in the signal transmission mode,
The correlation equation, which includes an undetermined coefficient and is a mathematical expression that uniquely indicates the relationship between the true value of the reference measurement device and the true value of the actual measurement device, is created based on the two theoretical expressions. Means to
Means for measuring the impedance of the correction data acquisition sample by the reference measurement device and the actual measurement device,
A means for specifying the undetermined coefficient by substituting the measured value of the impedance of the correction data acquisition sample measured by the two measurement devices into the correlation equation,
It has.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the present invention is implemented in a method of correcting a measurement error when measuring the impedance of an electronic component such as a surface-mounted chip coil as an electronic component to be measured using a measuring device having an impedance analyzer. Have been.
[0032]
FIG. 1 is a plan view showing a configuration of a measuring apparatus of the present embodiment, FIG. 2 is a plan view showing a configuration of a measuring jig, FIG. 3 is a block diagram showing an impedance analyzer constituting the measuring apparatus, FIG. 4 is a rear view showing the configuration of the sample to be measured (electronic component or correction data acquisition sample), and FIG. 5 is a plan view showing the configuration of the correction data acquisition sample.
[0033]
As shown in FIG. 1, the measuring devices constituting the reference measuring device 1 and the actual measuring device 2 include impedance analyzers 3A and 3B, a coaxial cable 4, and measuring jigs 5A and 5B. The impedance analyzer 3A and the measuring jig 5A are provided in the reference measuring device 1, and the network analyzer 3B and the measuring jig 5B are provided in the actual measuring device 2.
[0034]
The impedance analyzers 3A and 3B have one-port input / output units. The coaxial cable 4 is connected to this port. At the free end of the coaxial cable 4, a coaxial cable connector 6 is provided.
[0035]
As shown in FIG. 2, the measurement jigs 5A and 5B include an insulating substrate 7, a connection wiring section 8, and a coaxial connector 9. The connection wiring portion 8 is formed on the substrate surface 7a of the insulating substrate 7, and includes a signal transmission line 8a and ground lines 8b and 8c. The signal transmission path 8a extends from one end of the substrate toward the center of the substrate on the substrate surface 7a of the insulating substrate 7. The ground lines 8b and 8c are provided on both sides of the signal transmission line 8a at the center of the substrate surface 7a.
[0036]
The signal transmission line 8a is connected to an internal conductor contact (not shown) of the coaxial connector 9 at an end of the board. The ground lines 8b and 8c are connected to a ground pattern (not shown) on the back surface of the substrate via a through-hole connecting portion 10, and further, external conductor contacts (not shown) of the coaxial connector 9 via the ground pattern. It is connected to the.
[0037]
In FIG. 2, the measuring jig (hereinafter, referred to as a reference measuring jig) 5A of the reference measuring device 1 and the measuring jig (hereinafter, referred to as the actual measuring jig) 5B of the actual measuring device 2 have the same shape. However, they need not have the same shape. In particular, the shape of the actual measurement jig 5B may be different from that of the reference measurement jig 5A, for example, by making the shape suitable for an automatic sorting measuring machine or the like.
[0038]
As shown in FIG. 3, the impedance analyzer 3 </ b> B of the actual measurement device 2 includes an impedance analyzer body 20 and a control unit 21. The control unit 21 includes a control unit main body 22, a memory 23, a correlation formula calculating unit 24, and a correcting unit 25.
[0039]
As shown in FIG. 4, the measurement target electronic component 11A and the correction data acquisition sample 11B have a transmission line terminal 12a and ground terminals 12b and 12c on a back surface 11a. The transmission path terminal 12a and the ground terminals 12b and 12c are connected to the signal transmission path 8a and the ground line 8b by bringing the back surface 11a of the electronic component 11A to be measured or the correction data acquisition sample 11B into contact with the substrate surface 7a of the measurement jig 5. , 8c. As a result, the measurement target electronic component 11A and the correction data acquisition sample 11B are measured and mounted on the measurement jigs 5A and 5B.
[0040]
In the present embodiment, as the correction data acquisition sample 11B, a sample that generates an impedance equivalent to an arbitrary impedance of the electronic component 11A to be measured by the measurement operation by the measuring devices 1 and 2 is prepared. Further, in this embodiment, as the correction data acquisition sample 11B, a plurality (for example, three) of the samples 11B having different impedances generated by the measurement device are used._{1 ~ 3}Prepare. In general, there is no strictly identical electronic component having the same impedance. Therefore, the sample 11B_{1 ~ 3}However, even when general-purpose electronic components are used, their impedances are different from each other. However, the sample 11B having intentionally and strictly different impedance is used._{1 ~ 3}Is made as follows.
[0041]
That is, the correction data acquisition sample 11B in this case_{1 ~ 3}Has an insulating rectangular body 13 having a shape equivalent to that of the electronic component to be measured 11A, as shown in FIG. The insulating rectangular body 13 is provided with pseudo transmission line terminals 14a and pseudo ground terminals 14b and 14c having structures equivalent to the transmission line terminals 12a and the ground terminals 12b and 12c of the electronic component 11A to be measured. The pseudo transmission path terminal 14a and the pseudo ground terminals 14b and 14c are formed to extend from the lower surface of the frame 13 to the upper surface 13a via the side surfaces. Extending ends of the pseudo transmission path terminal 14a and the pseudo ground terminals 14b and 14c on the upper surface side of the rectangular body constitute mounting terminals 15a to 15c, respectively.
[0042]
Between the mounting terminals (15a and 15b) and (15a and 15c) adjacent to each other, impedance adjusting elements 16a and 16b including a resistance element and the like are mounted.
[0043]
The correction data acquisition element 11B on which the impedance adjustment elements 16a and 16b are mounted as described above._{1 ~ 3}Then, by arbitrarily setting the electrical characteristics (resistance value in the case of a resistance element) of the impedance adjusting elements 16a and 16b, the correction data acquisition sample 11B_{1 ~ 3}Can be set at random. In the present embodiment, the accurate value of the impedance generated by the measurement operation by the measurement device is determined by the correction data acquisition sample 11B._{1 ~ 3}Need not be set in advance. Therefore, the correction data acquisition sample 11B_{1 ~ 3}Can be kept low.
[0044]
Hereinafter, a method of correcting a measurement error (analytical relative correction method) by the measurement apparatus of the present embodiment will be described.
[0045]
First, the outline will be described. As a common problem in impedance measurement of a non-coaxial sample, there is a problem that the measurement result of the impedance differs depending on the measurement device. Specifically, the measurement result of the correction data acquisition sample 11B by the measuring device (the reference measuring device 1) including the jig (the reference measuring device 5A) for performing the user assurance and the jig (the actual measurement The problem is that the measurement result of the correction data acquisition sample 11B by the measuring device (actual measuring device 2) including the jig 5B) is different. Such inconsistency in the measurement results makes it impossible to guarantee the user at the time of shipping inspection.
[0046]
Therefore, in the present embodiment, for such a problem, the measurement result by the reference measurement device 1 is estimated from the measurement result by the actual measurement measurement device 2 by calculation based on the relative correction method.
[0047]
Hereinafter, the theory of the correction method (analytical relative correction method) of the present embodiment will be described.
[0048]
First, an error factor of each measurement system (the reference measurement device 1 and the actual measurement device 2) is modeled by a signal transmission form shown in FIG.
[0049]
In FIG. 6, F is an error factor of the measurement system. Z is the impedance value of the sample (the measurement target electronic component 11A and the correction sample acquisition sample 11B). V_MIs the voltage observed by the measuring devices 1 and 2. Voltage V_MIs a voltage applied to the subject sample and the error factor F. V_AIs the voltage actually applied to the test sample. I_MIs the current observed by the measuring devices 1 and 2. Current I_MIs a current flowing through the test sample and the error factor F. I_AIs the current actually flowing through the test sample.
[0050]
The error factor F is caused by, for example, resistance, inductance (residual impedance), cable capacitance (floating admittance), and the like of the measuring cable. When the error factor F is represented by a so-called F matrix, the following equation (1) is obtained.
[0051]
(Equation 1)

Here, the impedance Z measured by the measuring devices 1 and 2_MIs obtained by the following equations (2) and (2 ').
Z_M= V_M/ I_M  … (2)
Z_A= V_A/ I_A  ... (2 ')
By substituting the equations (2) and (2 ') into the equation (1), the following equation (3) is obtained.
Z_A= (DZ_M−B) / (C · Z)_M-A)… (3)
Z in the above equation (3)_AIndicates the true impedance value of the test sample. The above equation (3) is a rational equation, and one of the four unknowns A, B, C, and D constituting the error factor (hereinafter, these unknowns are referred to as error terms A to D) is obviously freely selected. be able to. Therefore, for example, by setting the error term D = 1 and determining the remaining three error terms A, B, and C, the impedance Z observed by the measuring devices 1 and 2 is determined._MFrom the true impedance Z of the specimen_ACan be determined.
[0052]
However, when the test sample has a non-coaxial shape, it is almost impossible at present to produce a standard device (an electronic component functioning as a standard device) having a known impedance in a high frequency band of about 1 MHz to several GHz. is there.
[0053]
Therefore, in the present embodiment, the measurement value of the test sample in the reference measurement device is accurately estimated by correcting the measurement value of the test sample in the actual measurement measurement device as follows. Here, first, the measurement error factor F₁Error term A that determines₁, B₁, C₁, D₁Is identified, and the impedance measurement value Z of the correction data acquisition sample 11B is identified by the reference measurement device 1._M1Is measured.
[0054]
In this case, the true impedance Z of the correction data acquisition sample 11B is obtained._AIs the impedance measured value Z by the reference measuring device 1._M1From the following theoretical equation (4).
Z_A= (D₁・ Z_M1-B₁) / (C₁・ Z_M1-A₁…… (4)
Similarly, the measurement error factor F₂Error term A that determines₂, B₂, C₂, D₂Is measured, and the impedance measurement value Z of the correction data acquisition sample 11B is measured by the actual measurement device 2._M2Is measured.
[0055]
In this case, the true impedance Z of the correction data acquisition sample 11B is obtained._AIs the impedance measured value Z by the actual measurement device 2_M2From the following theoretical equation (5).
Z_A= (D₂・ Z_M2-B₂) / (C₂・ Z_M2-A₂…… (5)
Here, even if the measurement systems are different, since the same correction data acquisition sample 11B is measured, the true impedance Z_AAre equal. Therefore, the right sides of the theoretical equation (4) and the theoretical equation (5) are equal. Therefore, the following equation (6) holds.
[0056]

Further, the following equation (7) is obtained by rearranging the above equation (6).
[0057]

In the above equation (7), the numerator and denominator on the right side are (A₁・ D₂-B₁・ C₂), And then performing an appropriate variable conversion, the following equation (8) having three undetermined coefficients is obtained. Equation (8) is a relative correction equation for impedance measurement in the present invention.
Z_M1= (Z_M2+ Α) / (β · Z_M2+ Γ)… (8)
If the undetermined coefficients α, β, and γ can be identified in the above interrelation equation (8), the measurement result Z of the actual measurement measurement device 2 is obtained._M2From the measurement result Z by the reference measuring device 1_M1Can be estimated with high accuracy.
[0058]
Assuming that the reference measurement device 1 is a perfect measurement device having no error factor F, the ideal relative measurement between the reference measurement device 1 and the actual measurement device 2 is performed. Such a relative correction should coincide with the above (7) which is an error elimination formula of the one-port measurement system.
[0059]
In fact, when the reference measuring device 1 is regarded as a perfect device without the error factor F, the coefficient A₁= 1, B₁= 0, C₁= 0, D₁= 1. Then, the impedance measurement value Z obtained by the above-mentioned correlation equation (8) is obtained._M1Is the impedance measurement value Z obtained by the above equation (7)._M1Matches the value of.
[0060]
In the above interrelation (8), three undetermined coefficients α, β, and γ are included, and Z_M1And Z_M2Are the values obtained from the measurements. Therefore, if three samples are prepared as the correction data acquisition samples 11B and the impedances of these correction data acquisition samples 11B are measured by the reference measurement device 1 and the actual measurement measurement device 2, the undetermined coefficients α, β, γ can be identified. That is, if this error correction method is used, the true impedance value of the correction data acquisition sample 11B and the error terms A₁, B₁, C₁, D₁, A₂, B₂, C₂, D₂The unknown coefficients α, β, and γ can be identified even if they are completely unknown.
[0061]
By substituting the impedance measurement values of the three correction data acquisition samples 11B in the correlation equation (8) and rearranging the same, the following correlation equation (9) is obtained.
[0062]
(Equation 2)

It should be noted that the interrelation formulas in the present invention shown in (8) and (9) are relationships that uniquely indicate the relationship between the true value of the measured value of the reference measuring device 1 and the true value of the measured value of the actual measuring device 2. It is an expression. Here, "unique" means that both true values almost exactly match. The term “approximately accurate” as used herein refers to a correction accuracy that is within a correction error of ± 0.8%, as described later with reference to FIG.
[0063]
In the equation (9), Z_{M2 (1)}, Z_{M2 (2)}, Z_{M1 (1)}Subscript, as shown in etc._{M1, M2}Number added to the end of_{(1), (2), (3)}Indicates the correction data acquisition sample 11B with the number_{1 ~ 3}Is the measured value of the impedance.
[0064]
In the correction method described above, the undetermined coefficients α, β, and γ are calculated by using three correction data acquisition samples 11B._{1 ~ 3}Measured impedance Z of_{M2 (1) ~ M2 (3)}Is calculated as a solution of the three-dimensional linear simultaneous equation. However, four or more correction data acquisition samples 11B_{1 ~ n}For the measured impedance Z_{M2 (1) ~ M2 (n)}, The undetermined coefficients α, β, and γ may be identified using a maximum likelihood method such as the least squares method. By doing so, it is possible to reduce the influence of a measurement error that occurs when measuring the correction data acquisition sample 11B.
[0065]
Although the above-mentioned interrelation equation (9) is a cubic determinant and has a mathematically very simple configuration, it takes time and effort to obtain a solution by manual calculation by an operator. Therefore, the calculation can be automated by calculating the above-described interrelation equation (9) using an algorithm widely used in automatic calculation using a computer, for example, an LU decomposition method.
[0066]
Next, the result of correction by the impedance correction method of the present invention will be described. FIG. 7 shows the configuration of the system that has performed the correction. In this system, the reference measurement device 1 and the actual measurement device 2 include an impedance analyzer 100, a reference measurement jig 101, and an actual measurement jig 102.
[0067]
The impedance analyzer 100 is composed of 4291A (manufactured by Agilent Technologies). The impedance analyzer 100 has a test head 100a. The test head 100a has a calibration surface 100b, and an APC7 (7 mm diameter connector) -SMA (3.5 mm diameter connector) conversion adapter 103 is attached to the calibration surface 100b. The reference measurement jig 101 and the actual measurement jig 102 have an SMA connector 104. By attaching the connector 104 to the adapter 103, the jigs 101 and 102 can be attached to the calibration surface 100b of the test head 100a. Has become.
[0068]
However, the actual measurement jig 102 is attached to the adapter 103 via a 3 dB attenuator (MKT: made by Taisei) 105 and a 1.5 m semi-flexible coaxial cable (made by FLEXCO) 106. The reason why the attenuator 105 and the coaxial cable 106 are interposed is to give a larger error to the impedance of the measurement target electronic component 11A mounted on the actual measurement jig 102 than would normally occur. This makes it easy to understand the high accuracy of the correction method of the present invention.
[0069]
In this configuration, the APC7-SMA conversion adapter 103 constitutes the coaxial cable connector 6 in FIG. 1, the SMA connector 104 constitutes the coaxial connector 9 in FIG. 2, and the reference measurement jig 101 is the reference measurement jig. 5A, and the actual measurement jig 102 constitutes the actual measurement jig 5B.
[0070]
In the above system, if the reference measurement jig 101 is attached to the impedance analyzer 100, it can be regarded as the reference measurement device 1. If the measurement fixture 102 is attached to the impedance analyzer 100, it can be regarded as the measurement device 2.
[0071]
In the system described above, each of the correction data acquisition samples 11B of open, short, and termination is obtained._{1 ~ 3}Are mounted on a reference measurement jig 101 and an actual measurement jig 102. Then, the impedance is measured by connecting each of the jigs 101 and 102 to the test head 100a. Furthermore, the undetermined coefficients α, β, and γ are identified by substituting the measured impedance values obtained by the measurement into the above-described correlation equation (9). The impedance is measured in a frequency range of 1 MHz to 100 NHz in 201 points.
[0072]
Next, the electronic component 11A to be measured including a capacitor, an inductor, a 100Ω resistor, and a 330Ω resistor._{1 ~ 4}Are prepared, and these electronic components to be measured 11A_{1 ~ 4}Is mounted on the measurement jig 102. Then, by connecting the measurement jig 102 to the test head 100a, the electronic component 11A to be measured is connected._{1 ~ 4}Is measured by the impedance analyzer 100.
[0073]
Obtained impedance measurement value Z_{M2 (1) ~ M2 (4)}By substituting (corresponding to the measured value of the actual measurement device 2) into the interrelation formulas (8) and (9) for which the undetermined coefficients α, β, and γ have been identified, the reference measurement device 1 is obtained. Measured value Z_{M1 (1) ~ M1 (4)}Is estimated.
[0074]
Next, the measurement target electronic component 11A_{1 ~ 4}Is mounted on the reference measurement jig 101. Then, by connecting the reference measurement jig 101 to the test head 100a, the electronic component 11A to be measured is connected._{1 ~ 4}Is measured by the impedance analyzer 100. Impedance measurement values of the measurement target electronic components 11A1 to 11A4 obtained by the measurement (the true value Z measured by the reference measurement device 1)_{A1 ~ 4}) And the measured value Z of the reference measuring device 1 estimated earlier._{M1 (1) ~ M1 (4)}Compare with The comparison results are shown in FIG. 8 and FIG.
[0075]
FIG. 8 shows the measurement results, and FIG. 9 shows the error fluctuation of the measurement values of the 100Ω resistor and the 330Ω resistor. In FIG. 8, the horizontal axis represents frequency, and the vertical axis represents impedance value. In FIG. 9, the horizontal axis indicates frequency, and the vertical axis indicates error accuracy.
In these figures, true L, true C, true 100, and true 330 indicate the measurement results of the inductor, the capacitor, the 100Ω resistance, and the 330Ω resistance of the reference measurement device 1 (reference measurement jig 100), respectively. I have. No L, No C, No 100, and No 330 indicate the measurement results of the inductor, the capacitor, the 100Ω resistor, and the 330Ω resistor, respectively, with the actual measurement device 2 (the actual measurement jig 102). Relative L, Relative C, Relative 100, and Relative 330 indicate correction values of the inductor, the capacitor, the 100Ω resistance, and the 330Ω resistance in the actual measurement device 2 (actual measurement jig 102), respectively.
[0076]
As is apparent from these figures, the correction is accurately performed within ± 0.8% by implementing the correction method of the present invention.
[0077]
Hereinafter, a correction method according to the measurement error correction method of the present embodiment will be specifically described.
[0078]
The prepared three correction data acquisition samples 11B_{1 ~ 3}Is mounted on the reference measurement device 1. And each sample 11B_{1 ~ 3}Is measured at each frequency point. Correction data acquisition sample 11B in these reference measurement devices 1_{1 ~ 3}Of the actual measurement device 2 is input in advance to the actual measurement device 2 via a data input unit (not shown) of the actual measurement device 2. The input measurement result of the reference measurement device 1 is stored in the memory 23 via the control unit main body 22.
[0079]
On the other hand, in the actual measurement device 2, similarly, the correction data acquisition sample 11B_{1 ~ 3}Is mounted on the reference measurement device 2. Then, the correction data acquisition sample 11B_{1 ~ 3}Is measured at each frequency point.
[0080]
Correction data acquisition sample 11B by measurement device 2_{1 ~ 3}Is input to the correlation formula calculating means 24 via the control unit main body 2.
[0081]
The correlation expression calculating means 24 calculates the correction data acquisition sample 11B by the actual measurement device 2._{1 ~ 3}Is input from the memory 23 via the control unit main body 22, the correction data acquisition sample 11B measured by the reference measurement device 1._{1 ~ 3}Read the measurement result of.
[0082]
The reciprocal equation calculating means 24 calculates a reciprocal equation between the measurement result of the actual measurement apparatus 2 and the measurement result of the reference measurement apparatus 1 based on the measurement result of the reference measurement apparatus 1 and the measurement result of the actual measurement apparatus 2. Is calculated. The calculation is performed based on the above-described interrelation equations (8) and (9).
[0083]
After the above preparation steps, the impedance of the electrical component 11A to be measured is measured by the impedance analyzer body 20 of the actual measurement and measurement device 2. The measurement result of the electric component 11A to be measured is input to the correction unit 25 via the control unit main body 22.
[0084]
When the measurement result of the electric component 11A to be measured is input, the correction unit 25 reads a correlation equation from the memory 23 via the control unit main body 22. The correction means 25 calculates by substituting the impedance value, which is the measurement result of the electric component 11A, into the read correlation equation. Thereby, the correction unit 25 corrects the measurement result (impedance) of the measurement target electrical component 11A in the actual measurement measurement device 2 to the impedance estimated to be obtained when measured by the reference measurement device 1. The correction unit 25 outputs the calculated correction value (impedance) to the outside via the control unit main body 22. The output may be displayed on a display unit (not shown) or output as data by a data output unit (not shown).
[0085]
Note that such calculation processing may be performed by the control unit 21 built in the impedance analyzer 3B as described above, or the measurement result may be output to an external computer connected to the impedance analyzer 3 It may be performed by an external computer.
[0086]
According to the method for correcting the measurement result of the present embodiment described above, the following effects are obtained. That is, when the electronic component manufacturer guarantees the impedance of the electronic component, the impedance is guaranteed based on the result measured by the measuring device provided on the manufacturer side. However, even when measuring the impedance of the electronic component in a measuring device provided on the user side who purchased the electronic component, an equivalent measurement result is not always obtained. Therefore, with this, the impedance guaranteed by the manufacturer cannot be confirmed, and the guarantee is not reproducible and uncertain.
[0087]
On the other hand, if the measuring device on the maker side is used as the reference measuring device 1 and the measuring device 2 on the user side is used as the actual measuring device and the method for correcting the measurement error of the present embodiment is performed, the measurement results on the maker side are obtained. The impedance estimated to be equivalent to can be calculated on the user side based on the measurement result of the actual measurement device 2 on the user side. As a result, it is possible to reproduce the guarantee of the electronic component performed by the manufacturer side, and it becomes sufficiently reliable, so that it can be accepted by the user.
[0088]
In addition, the state of the actual measurement device 2 is strictly inspected and managed (for example, the characteristics of the actual measurement jig 5B of the actual measurement device 2 are adjusted to be equal to the characteristics of the reference measurement jig 5A of the standard measurement device 1). Since the above-mentioned correction can be performed without performing the management, the cost required for the measurement can be reduced accordingly.
[0089]
Further, on the manufacturer side, it is also possible to select a large number of automatic measurement and sorting machines installed during the mass production process as the actual measurement measuring device, and accordingly, the cost required for the measurement (in this case, a defective component in this case) (Sorting cost) can be suppressed, and the measurement time can be shortened.
[0090]
In addition, since it is possible to simultaneously correct not only the measurement errors caused by the measurement jigs 5A and 5B, but also the measurement errors of the entire measurement device 2, it is necessary to perform a special calibration in the measurement device 2. The measurement cost can be further reduced.
[0091]
Furthermore, in the measuring apparatus of the present embodiment, even if an actual measurement jig 5B is used in which the built-in performance and long life of the automatic measurement and sorting machine are prioritized over the stabilization of the measurement characteristics, the measurement results are not affected at all. Absent. Therefore, the cost for the measurement can be further reduced, and the measurement time can be shortened.
[0092]
【The invention's effect】
As described above, according to the present invention, it is possible to correct the measurement result of the actual measurement in which the measurement result does not completely match the reference measurement device, as well as the measurement result of the reference measurement device.
[Brief description of the drawings]
FIG. 1 is a plan view showing a schematic configuration of a measuring apparatus for implementing a measurement error correcting method according to the present invention.
FIG. 2 is a plan view showing the configuration of a measuring jig that constitutes a measuring device that implements the measuring error correction method of the present invention.
FIG. 3 is a block diagram illustrating a configuration of a measurement apparatus that implements a measurement error correction method according to the present invention.
FIG. 4 is a rear view showing the configuration of a correction data acquisition sample and an electrical component to be measured, which constitute a measuring apparatus for implementing the measurement error correction method of the present invention.
FIG. 5 is a plan view showing a configuration of a correction data acquisition sample that constitutes a measurement device that implements the measurement error correction method of the present invention.
FIG. 6 is an example of a signal transmission form (error model) used when implementing the measurement error correction method of the present invention.
FIG. 7 is a diagram showing a configuration of a system corrected by the impedance correction method of the present invention.
FIG. 8 is a diagram showing correction data and measurement results obtained by performing the measurement error correction method of the present invention.
FIG. 9 is a diagram illustrating error accuracy of correction data obtained by performing the measurement error correction method of the present invention.
[Explanation of symbols]
1 Reference measuring device
2 Measurement equipment
3A, 3B impedance analyzer
4 Coaxial cable
5A, 5B measuring jig
6 Coaxial cable connector
7 Insulating substrate
8a Signal transmission path
8b, 8c ground line
9 Coaxial connector
10 Through-hole connection
11A Electronic components to be measured
11B Correction data acquisition sample
12a Transmission line terminal
12b, 12c Ground terminal
13 Frame
14a pseudo transmission line terminal
14b, 14c pseudo ground terminal
15a-15c Mounting terminal
16a-16e Impedance adjusting element
20 Impedance analyzer body
21 Control unit
22 Control unit body
23 memory
24 Means for calculating relational expressions
25 Correction means
100 impedance analyzer
100a test head
100b Calibration surface
101 Reference measurement jig
102 Measurement fixture
103 APC7-SMA Conversion Adapter
104 SMA connector
105 attenuator
106 Coaxial cable

Claims (5)

The impedance of the electronic component to be measured is measured by an actual measurement device whose impedance measurement result does not match the reference measurement device, and then the measured value is estimated to be obtained when measured using the reference measurement device. Correction method of the measurement error to be corrected to
In advance, a step of preparing a correction data acquisition sample that generates an impedance equivalent to an arbitrary impedance of the electronic component to be measured by a measurement operation as a correction data acquisition sample,
The step of measuring the impedance of the correction data acquisition sample by the reference measurement device and the actual measurement device, respectively.
Determining a correlation equation between the measurement result by the actual measurement device and the measurement result by the reference measurement device,
By substituting the impedance of the electric component to be measured measured by the actual measuring device into the interrelation formula and calculating the interrelation formula, the impedance of the electric component to be measured was measured by the reference measuring device. Correcting to the impedance estimated to be obtained in the case;
A method for correcting a measurement error. The method for correcting a measurement error according to claim 1,
The step of obtaining the interrelation equation includes:
Procedure for assuming the signal transmission form of the two measurement devices at the time of measurement, including a measurement error factor,
A theoretical formula for calculating the true value of the measurement value of the actual measurement device in the signal transmission mode, and a theoretical formula for calculating the true value of the measurement value of the reference measurement device in the signal transmission mode, respectively,
The correlation equation, which includes an undetermined coefficient and is a mathematical expression that uniquely indicates the relationship between the true value of the reference measurement device and the true value of the actual measurement device, is created based on the two theoretical expressions. Steps to
The procedure of measuring the impedance of the correction data acquisition sample by the reference measurement device and the actual measurement device, respectively.
A procedure for identifying the undetermined coefficient by substituting the measured value of the impedance of the correction data acquisition sample measured by the two measurement devices into the correlation equation,
A method for correcting a measurement error. An electronic component to be measured whose impedance is a required characteristic when measured by a reference measurement device is measured by an actual measurement measurement device whose measurement result does not match the reference measurement device, and a pass / fail judgment is made based on the measurement result. Pass / fail judgment method,
An impedance of the electronic component to be measured measured by the actual measurement device is corrected by the method of correcting a measurement error according to claim 1, and the corrected impedance is compared with the required characteristic to measure the target component. Judge the quality of electronic components,
A method for judging the quality of an electronic component. An electronic component characteristic measuring device that has a measuring means for measuring the impedance of the electronic component to be measured, but whose measurement result does not match the reference measuring device,
A storage unit that stores a measurement result obtained by measuring the impedance of the correction data acquisition sample that generates an impedance equivalent to the impedance of the electronic component to be measured by the reference measurement device,
Calculation of a correlation equation for calculating a correlation equation between the impedance of the correction data acquisition sample measured by the measurement means and the impedance of the correction data acquisition sample by the reference measurement device stored in the storage means. Means,
When the impedance of the electrical component to be measured is measured by the reference measuring device by substituting the impedance of the electrical component to be measured measured by the measuring means into the interrelation equation and calculating the interrelation equation. Correction means for correcting the impedance to be obtained to
An electronic component characteristic measuring device comprising: The electronic component characteristic measuring device according to claim 4,
The interrelation formula calculating means,
Means for assuming the signal transmission form of the two measuring devices at the time of measurement, including a measurement error factor,
A theoretical formula for calculating the true value of the measurement value of the actual measurement device in the signal transmission mode, and a theoretical formula for calculating the true value of the measurement value of the reference measurement device in the signal transmission mode,
The correlation equation, which includes an undetermined coefficient and is a mathematical expression that uniquely indicates the relationship between the true value of the reference measurement device and the true value of the actual measurement device, is created based on the two theoretical expressions. Means to
Means for measuring the impedance of the correction data acquisition sample by the reference measurement device and the actual measurement device,
A means for specifying the undetermined coefficient by substituting the measured value of the impedance of the correction data acquisition sample measured by the two measurement devices into the correlation equation,
An electronic component characteristic measuring device comprising:

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