JP4671527B2

JP4671527B2 - Mounting component inspection method and inspection device

Info

Publication number: JP4671527B2
Application number: JP2001106549A
Authority: JP
Inventors: 大介永井
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2001-04-05
Filing date: 2001-04-05
Publication date: 2011-04-20
Anticipated expiration: 2021-04-05
Also published as: JP2002303590A

Description

【０００１】
【発明の属する技術分野】
本発明は、電子機器に使用されるプリント基板の実装工程において、プリント基板上に実装して半田付けされた後の電子部品である実装部品を検査する方法および装置に関し、特にチップ部品などの実装部品の装着位置ズレおよびチップ部品の誤装着を外観で検査する半田付け後のチップ部品の検査方法および装置に関するものである。
【０００２】
【従来の技術】
プリント基板上に実装された電子部品である実装部品の装着状態を非接触で検査する方法としては、特開平４−２０８８０３号公報に開示された検査装置がある。この検査装置においては、三角測量の原理を用いて、細く絞ったビーム光を実装済みプリント基板に照射し、その反射光を検出することで、計測点までの距離を計測し、前記ビーム光を計測対象となるプリント基板全面に走査させることで、実装済みプリント基板全面の高さ画像を取得するようになっている。
【０００３】
そして、前記取得された高さ画像をもとに前記プリント基板上に実装された部品の外形を認識することで実装部品の位置およびサイズを計測し、予め教示されたプリント基板上に実装されるべき部品の装着位置および部品サイズに適合するかどうかを判定している。つまり、実装部品の装着位置にズレを生じている場合には、接続状態不良などのおそれがあるため不良判定を行い、実装部品のサイズが適合していない場合には、異なった部品が装着されているおそれがあるため不良判定を行って、これらの不具合を防止するように図られている。
【０００４】
以下、図面を参照しながら、実装部品を認識するために実装部品の位置やサイズを計測する従来の方法について説明する。
図７の（ａ）および（ｂ）は、プリント基板に実装されて半田付けされたチップ部品を示す断面図および平面図である。部品本体１１の両側部に第一の電極１２と第二の電極１３とが設けられている実装部品としてのチップ部品１０は、プリント基板１８に形成された第一のランド１６と第二のランド１７とに跨るように実装される。そして、半田１４によりチップ部品１０の第一の電極１２と第一のランド１６とが接合され、半田１５によりチップ部品１０の第二の電極１３と第二のランド１７とが接合される。
【０００５】
また、図７の（ｃ）は、プリント基板１８上のチップ部品１０を撮像して得られた高さデータの断面プロファイルを概略的に示すもので、２１は高さデータの断面プロファイル、２２は２値化のための高さ閾値を表わす。この高さ閾値２２としては、高さデータの断面プロファイル２１に基づいて、電極１２、１３を含むチップ部品１０の外形形状２５を抽出することのできる適切な高さ閾値２２が用いられる。そして、チップ部品１０を上方から撮像して得られた濃淡画像を、前記高さ閾値２２で２値化して図７の（ｄ）に示すようなチップ部品１０の外形形状２５を得て、この外形形状２５を示す２値化画像に基づいてチップ部品１０の４つコーナー位置の認識もしくは、４辺の認識を行い、チップ部品１０の位置やサイズを計測し、予め教示されたチップ部品１０の装着位置や部品サイズに適合するかどうかを判定していた。
【０００６】
【発明が解決しようとする課題】
しかしながら、クリーム半田印刷の量が多い場合、もしくは半田槽を通すフロー半田付けの場合には、図８の（ａ）、（ｂ）に示すように、半田１４、１５がチップ部品１１の電極１２、１３上まで吸い上げられ、電極１２、１３の外側の端面、あるいはチップ部品１１の４つのコーナーが半田１４、１５により覆われてしまい、図８（ｃ）に示すように、チップ部品１０を計測して得られた高さデータを表す濃淡画像（高さデータの断面プロファイル）２１を、高さ閾値２２で２値化した際に、この２値化画像において、チップ部品１０の外形線２５が、半田部分も含めて２値化されて認識されるため、当該チップ部品１０における正規の４つコーナー位置およびチップ部品１０の外形を表わす４辺において、電極１２、１３側の端面の認識ができず、この結果、チップ部品１０の正確な位置およびサイズの計測ができないという問題が生じていた。
【０００７】
本発明は上記問題を解決するもので、実装部品における電極の外側の端面やコーナーが半田により覆われてしまった場合でも、実装部品の装着位置および部品サイズの良否を良好に判定することのできる実装部品の検査方法および検査装置を提供することを目的とするものである。
【０００８】
【課題を解決するための手段】
上記問題を解決するために本発明の実装部品の検査方法および検査装置は、実装部品の実装状態を入力して得た画像に基づいて実装部品の前記複数の電極と部品本体との境界線をそれぞれ検出し、これらの境界線の情報と予め入力されている実装部品に関する電極の位置およびサイズなどの情報とに基づいて実装部品の装着位置およびサイズを算出することで実装部品の装着位置および部品サイズの良否を判定し、実装部品の装着位置を算出する工程で、境界線を検出工程において検出した複数の境界線位置と、予め入力されている実装部品の電極の情報を含む形状に関する情報とに基づいて、実装部品の外形を算出する部品外形算出処理を行うものである。
【０００９】
本発明によれば、半田によりチップ部品などの実装部品の電極が覆われ、従来のように電極の部品外側位置の端面、あるいは実装部品のコーナーを認識することができない場合においても、半田に覆われる可能性の低い２箇所の電極と部品本体との境界線を検出することにより、正確に実装部品の装着位置およびサイズを決定できて正しい検査が行えるものである。
【００１０】
【発明の実施形態】
本発明の請求項１に記載の実装部品の検査方法は、実装済みプリント基板表面部分、すなわち、実装部品の実装状態を入力して得た画像に基づいて実装部品の前記複数の電極と部品本体との境界線をそれぞれ検出し、これらの境界線の情報と予め教示などにより入力されている実装部品に関する電極の位置およびサイズなどの情報とに基づいて実装部品の装着位置を算出することで実装部品の装着位置の良否を判定し、実装部品の装着位置を算出する工程で、境界線を検出工程において検出した複数の境界線位置と、予め入力されている実装部品の電極の情報を含む形状に関する情報とに基づいて、実装部品の外形を算出する部品外形算出処理を行うことを特徴としたものであり、部品の半田付けの状態に関わらず正確にチップ部品などの実装部品の装着位置を認識し、正しい検査をし得るものである。また、例えば、境界線検出処理により検出された２つの電極と部品本体との境界線位置より、予め教示された電極サイズ分を加算することにより外形を推定し、前記推定した外形より実装部品の中点を求めて、実装中心位置とする。
【００１１】
また、本発明の請求項２に記載の実装部品の検査方法は、装着位置を算出する工程で、境界線を検出する工程において検出した複数の境界線位置から実装部品の中心位置を算出する部品中心位置算出処理を行うもので、例えば、境界線検出処理により検出された２つの電極と部品本体との境界線位置の中点を、実装部品における電極に沿う方向の中心位置とする。
【００１４】
（実施の形態１）
図１は本発明の実施の形態に係る実装部品の検査装置の斜視図であり、この検査装置により、実装済みプリント基板表面部分の高さおよび、基板表面からの反射光量を計測する動作を行うものであり、図１はこの原理を説明している。なお、従来のものと同様のものには同符号を付す。
【００１５】
図１に示すように、検査装置は、被検体である実装済みプリント基板２のチップ部品（実装部品）１０にレーザ光Ｌを真上から照射するレーザーユニット１と、プリント基板２のチップ部品１０で反射された光を受ける４つの位置敏感検出器（ＰＳＤ：Position Sensitive Detector）４Ａ，４Ｂ，４Ｃ，４Ｄとを備えており、三角測量の原理に基づいて被検体であるプリント基板２の表面形状データを計測する。また、記憶機能や演算機能を有して、後述する処理を行う制御手段（図示せず）なども備えられている。位置敏感検出器４Ａ〜４Ｄは、レーザ光Ｌを受光した位置に応じて２つのアナログ信号を出力するセンサとして機能する。
【００１６】
三角測量の原理から、レーザ光Ｌの照射源座標（Ｘ，Ｙ，Ｚ）、被検体上の照射位置座標（Ｘ，Ｙ）、各位置敏感検出器４Ａ〜４Ｄにおけるレーザ光受光座標（Ｘａ，Ｙａ，Ｚａ）、（Ｘｂ，Ｙｂ，Ｚｂ）、（Ｘｃ，Ｙｃ，Ｚｃ）、（Ｘｄ，Ｙｄ，Ｚｄ）により、被検体上の照射位置における高さ座標が算出される。
【００１７】
位置敏感検出器４Ａ〜４Ｄから出力されたアナログ信号を下記の式（１）に基づいて変換処理することにより被検体の高さデータが算出される。下記式（１）と式（２）において、Ｈ（ｘ，ｙ）は照射位置であるサンプリング座標点（ｘ，ｙ）において計測した高さの値を示しており、Ｂ（ｘ，ｙ）はサンプリング座標点（ｘ，ｙ）において計測した輝度値（反射強度）である。また、Ｉａ（ｘ，ｙ）とＩｂ（ｘ，ｙ）はサンプリング座標点（ｘ，ｙ）において計測した各位置敏感検出器４Ａ〜４Ｄからの信号値である。各位置敏感検出器４Ａ〜４Ｄの出力信号である２つの信号値Ｉａ（ｘ，ｙ）とＩｂ（ｘ，ｙ）とを加算することにより、そのサンプリング座標点（ｘ，ｙ）における輝度値（Ｂ（ｘ，ｙ））が表される。
Ｈ（ｘ，ｙ）＝Ｉａ（ｘ，ｙ）／（Ｉａ（ｘ，ｙ）＋Ｉｂ（ｘ，ｙ））・・式１
Ｂ（ｘ，ｙ）＝Ｉａ（ｘ，ｙ）＋Ｉｂ（ｘ，ｙ）・・式２
被検体の２次元領域における表面形状データ（高さデータ）の計測は、サンプリング座標点を固定したまま被検体をＸ，Ｙ平面内で平行移動させて繰り返し行うか、あるいは被検体を固定した状態でサンプリング座標点を並行移動させて繰り返し行う。
【００１８】
なお、上記以外の装置を用いて表面形状データを計測する方法としては、例えばスリット光の変化により高さデータを計測する光切断法や、２つ以上の視差画像から高さデータを計測するステレオ法等があり、またＸ線ＣＴ装置（x-ray Computed Tomography System）やＭＲＩ装置（Magnetic Resonance Imaging System）等によって計測した３次元データから表面形状データを取得することも可能である。
【００１９】
これらの方法により、被検体であるプリント基板２に実装部品としてのチップ部品１０が実装された状態が濃淡画像として取得できるるとともに、チップ部品１０が実装されたプリント基板２の高さを認識できる画像を得ることができる。
【００２０】
次に、上記検査装置において撮像した高さ画像と輝度画像とを用いてチップ部品位置の検査およびチップ部品サイズの検査を実施する。図２はこの検査処理を示すフローチャートである。
【００２１】
まず、ステップＳＴ１０において、前記検査装置で、部品実装済みのプリント基板２全面の高さデータおよび輝度データを計測する。
そして、ステップＳＴ２０において、前記高さデータを用いて、被検体における平面視して短い長さの辺に沿う方向（短手方向と称す）の部品エッジ検出処理を実行する。図３により、エッジ検出処理を実行するウインドウ３１、３２、３３３、３４を示す。前記エッジ検出ウインドウ３１〜３４を、予め教示されたプリント基板２およびチップ部品１０の装着位置の情報に基づいて、半田付け状態によるエッジ検出精度の影響の受けないと想定される箇所に設定し、前記ウインドウ３１〜３４内の高さデータの変化点を検出して、エッジ点とする。ウインドウ３１、３２で検出された２つのエッジ点のデータから、半田が付かない側（短手方向）における一方の辺の位置が求まり、ウインドウ３３、３４で検出された２つのエッジ点のデータから、半田が付かない側（短手方向）における他方の辺の位置が求まる。また、ウインドウ３１、３３で検出された２つのエッジ点の中点と、ウインドウ３２、３４で検出された２つのエッジ点の中点とを結ぶ直線が、半田が付く方向（長手方向）の中心線Ａとなり、この中心線Ａの側方から見た直線部分と水平線とのなす角度が部品の装着回転角度（装着傾斜角度）となる。
【００２２】
次に、ステップＳＴ３０において、前記高さデータおよび輝度データを用いて、電極１２、１３と部品本体１１との境界線位置を検出し、この境界線位置に基づいて、長手方向（半田により部品エッジが覆われる方向）の部品エッジを検出する。なお、長手方向の部品エッジ検出処理については後述する。
【００２３】
次に、ステップＳＴ４０において、ステップＳＴ２０、ＳＴ３０で検出されたエッジ座標よりチップ部品１０の位置およびサイズの算出処理を実行する。
最後に、ステップＳＴ５０において、チップ部品１０の装着位置については、ステップＳＴ４０で算出されたチップ部品１０の装着位置と、予め教示されたチップ部品１０の適正装着位置とのズレ量が、予め教示されたズレ許容値以下であるかどうかを比較し、前記ズレ量が前記ズレ許容値以下であれば良品、前記ズレ量が前記ズレ許容値より大きければ不良と判断する。
【００２４】
部品サイズについては、ステップＳＴ４０で算出したチップ部品１０のサイズと、予め教示されたチップ部品１０のサイズとの差が、予め教示されたサイズ許容値以下であるかどうかを比較し、前記サイズの差が前記サイズ許容値以下であれば良品、前記サイズの差が前記サイズ許容値よりも大きければ不良と判断する。
【００２５】
ここで、上記ステップＳＴ３０の長手方向の部品エッジ検出処理についてさらに詳しく説明する。図４は、長手方向の部品エッジ検出処理ステップＳＴ３０を示すフローチャートである。
【００２６】
まず、ステップＳＴ３１において、処理対象領域を決定する。図５は、長手方向の部品エッジ検出処理を実行するための処理対象領域を示した図である。予めティーチングされたチップ部品１０の装着位置に関する情報と、チップ部品１０の形状に関する情報である部品中心位置座標４１と、電極１２、１３の部品中心位置からの相対座標および部品ズレ許容範囲４２とにより、一つのチップ部品１０に対して第一の処理対象領域４３と第二の処理対象領域４４との二つの処理領域を決定する。
【００２７】
そして、ステップＳＴ３２において、前述したステップＳＴ３１で決定した第一の処理対象領域４３の高さ画像を読込む。また、ステップＳＴ３３において、前記高さ画像を、部品形状を抽出することのできるチップ部品１０の高さよりやや低めの高さ閾値で２値化し、マスク領域を０、非マスク領域を１としたマスク画像を生成する。
【００２８】
次に、ステップＳＴ３４において、前述したステップＳＴ３１で決定した第一の処理対象領域４３の輝度画像を読込む。そして、ステップＳＴ３５において、前記読み込んだ輝度画像とステップＳＴ３４で抽出したマスク処理領域との画像間演算を行い、電極１２、１３と部品本体１１との境界線位置検出処理領域の絞込みを行う。
【００２９】
さらに、ステップＳＴ３６において、ステップＳＴ３５により得られたマスク処理を施された輝度画像に対し、例えば図６に示す微分オペレータを施す。そして、微分処理された処理画像においてある値以上の値を示す座標の最小二乗近似直線を求めることにより電極１２と部品本体１１との境界線を検出する電極本体境界線検出処理を実行する。
【００３０】
なお、本実施の形態では、輝度画像が、反射光量の高い電極１２の部分で高く、反射光量の低い部品本体１１の部分で低く計測される特徴に対応させて、微分処理により電極１２と部品本体１１との境界線位置を検出したが、ステップＳＴ３５により得られたマスク処理を施された輝度画像において、電極１２のみを抽出できる閾値により２値化した画像に対して輪郭線を抽出して、電極１２と部品本体１１との境界線を検出することも可能である。
【００３１】
また、ステップＳＴ３７において、ステップＳＴ３１で決定された第二の処理対象領域４４について、処理を実行済みかどうかの判断を実行する。そして、未実行の場合、第二の処理対象領域４４に対し、ステップＳＴ３２からステップＳＴ３６までの処理を実行し、ステップＳＴ３１で決定された第一の処理対象領域４３および第二の処理対象領域４４のそれぞれの処理領域に対し、二つの電極１２、１３と部品本体１１との境界線を検出する。
【００３２】
そして、ステップＳＴ３８において、ステップＳＴ３７で検出した２つの電極１２、１３と部品本体１１との境界線位置と、予め教示された電極１２、１３の幅とにより、チップ部品１０の外形エッジ座標を算出する。
【００３３】
これにより、チップ部品１０の外形エッジ座標を算出して、上述したように、ステップＳＴ４０で、エッジ座標よりチップ部品１０の装着位置およびサイズの算出処理を実行することで、半田１４、１５によりチップ部品１０の電極１２、１３が覆われている場合でも、正確にチップ部品１０の装着位置およびサイズを決定でき、チップ部品１０の装着位置やサイズに関して正しい検査が行える。
【００３４】
なお、上記実施の形態においては、部品本体１１の両側部の２箇所に電極１２、１３がある場合を述べたが、これに限るものではなく、部品本体の４隅箇所など、部品本体１１の複数の端部箇所に電極がある場合にも上記検査方法を適用可能である。
【００３５】
【発明の効果】
以上のように、本発明によれば、半田により実装部品の電極が覆われ、従来のように電極の部品外側の端面、あるいは実装部品のコーナーを認識することができない場合においても、半田に覆われる可能性の低い複数箇所の電極と部品本体との境界線を検出することにより、正確にチップ部品などの実装部品の装着位置およびサイズを決定できて正しい検査が行え、これにより検査の信頼性が向上する。
【図面の簡単な説明】
【図１】本発明の実施の形態にかかる検査装置の概略的な斜視図である。
【図２】本発明の実施の形態にかかる検査方法を示すフローチャートである。
【図３】同検査方法における短手方向の部品エッジ検出処理を示す図である。
【図４】同検査方法における長手方向の部品エッジ検出処理を示すフローチャートである。
【図５】同検査方法における処理対象領域を示す図である。
【図６】同検査方法における輝度画像の微分処理のマスクパターンを示す図である。
【図７】（ａ）はプリント基板に実装されて半田付けされたチップ部品の断面図である。
（ｂ）は半田付けされたチップ部品を上面から見た図である。
（ｃ）は同チップ部品の高さデータの断面プロファイルを示した図である。
（ｄ）は従来の検査方法によりチップ部品を２値化した画像を示す図である。
【図８】従来の検査方法の課題を示すもので、（ａ）はチップ部品の断面図、（ｂ）は半田付けされたチップ部品を上面から見た平面図、（ｃ）は同チップ部品の高さデータの断面プロファイル、（ｄ）は同チップ部品を２値化した画像を示す図である。
【符号の説明】
１レーザーユニット
２プリント基板
４Ａ〜４Ｄ位置敏感検出器
１０チップ部品（実装部品）
１１部品本体
１２、１３電極
１４、１５半田[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for inspecting a mounting component, which is an electronic component after being mounted on a printed circuit board and soldered, in a mounting process of a printed circuit board used in an electronic device, and in particular, mounting of a chip component or the like The present invention relates to a method and an apparatus for inspecting a chip component after soldering to inspect the mounting position shift of the component and the erroneous mounting of the chip component by appearance.
[0002]
[Prior art]
As a method for inspecting the mounting state of a mounted component, which is an electronic component mounted on a printed circuit board, in a non-contact manner, there is an inspection device disclosed in Japanese Patent Laid-Open No. 4-208803. In this inspection apparatus, using the principle of triangulation, the mounted printed circuit board is irradiated with a narrowly focused beam light, and the reflected light is detected to measure the distance to the measurement point, and the beam light is By scanning the entire surface of the printed circuit board to be measured, a height image of the entire surface of the mounted printed circuit board is acquired.
[0003]
Then, the position and size of the mounted component are measured by recognizing the external shape of the component mounted on the printed circuit board based on the acquired height image, and mounted on the printed circuit board taught in advance. It is determined whether or not it matches the mounting position and the component size of the component to be. In other words, if there is a deviation in the mounting position of the mounted component, there is a risk of a connection state failure, etc., so a failure determination is made, and if the size of the mounted component does not fit, a different component is mounted. In order to prevent these problems, a failure determination is performed.
[0004]
Hereinafter, a conventional method for measuring the position and size of a mounted component in order to recognize the mounted component will be described with reference to the drawings.
7A and 7B are a cross-sectional view and a plan view showing a chip component mounted on a printed circuit board and soldered. The chip component 10 as a mounting component in which the first electrode 12 and the second electrode 13 are provided on both sides of the component main body 11 includes a first land 16 and a second land formed on the printed circuit board 18. It is mounted so as to straddle 17. Then, the first electrode 12 and the first land 16 of the chip component 10 are joined by the solder 14, and the second electrode 13 and the second land 17 of the chip component 10 are joined by the solder 15.
[0005]
FIG. 7C schematically shows a cross-sectional profile of height data obtained by imaging the chip component 10 on the printed board 18, 21 is a cross-sectional profile of height data, and 22 is This represents the height threshold for binarization. As the height threshold 22, an appropriate height threshold 22 that can extract the outer shape 25 of the chip component 10 including the electrodes 12 and 13 based on the cross-sectional profile 21 of the height data is used. Then, the grayscale image obtained by imaging the chip component 10 from above is binarized by the height threshold 22 to obtain the outer shape 25 of the chip component 10 as shown in FIG. Based on the binarized image showing the outer shape 25, the four corner positions or the four sides of the chip component 10 are recognized, the position and size of the chip component 10 are measured, and the chip component 10 taught in advance is measured. It was determined whether it fits the mounting position and part size.
[0006]
[Problems to be solved by the invention]
However, when the amount of cream solder printing is large, or in the case of flow soldering through a solder bath, the solders 14 and 15 are the electrodes 12 of the chip component 11 as shown in FIGS. 13, the outer end surfaces of the electrodes 12, 13 or the four corners of the chip component 11 are covered with the solders 14, 15, and the chip component 10 is measured as shown in FIG. When the grayscale image (height data cross-sectional profile) 21 representing the height data obtained by binarization is binarized with the height threshold value 22, the outline 25 of the chip component 10 is displayed in the binarized image. Since the binarization including the solder portion is recognized, the end faces on the electrodes 12 and 13 side are recognized at the four regular corner positions of the chip component 10 and the four sides representing the outer shape of the chip component 10. Can not, as a result, a problem that can not be exact position and size of the measurement of the chip component 10 has occurred.
[0007]
The present invention solves the above-mentioned problem, and even when the end face or corner of the outer side of the electrode in the mounting component is covered with solder, the mounting position of the mounting component and the quality of the component size can be determined satisfactorily. It is an object of the present invention to provide a mounting component inspection method and inspection apparatus.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, a mounting component inspection method and inspection apparatus according to the present invention provides a boundary line between the plurality of electrodes of a mounting component and a component body based on an image obtained by inputting a mounting state of the mounting component. The mounting position and component of the mounting component are calculated by detecting the respective boundary lines and calculating the mounting position and size of the mounting component on the basis of information about the position and size of the electrode relating to the mounting component that is input in advance. In the step of determining the quality of the size and calculating the mounting position of the mounting component, a plurality of boundary line positions detected in the detection step of the boundary line, and information on the shape including information of electrodes of the mounting component input in advance Based on the above, a component outer shape calculation process for calculating the outer shape of the mounted component is performed .
[0009]
According to the present invention, an electrode of a mounting component such as a chip component is covered with solder, and even when the end surface of the electrode outside the component or the corner of the mounting component cannot be recognized as in the prior art, the solder is covered. By detecting the boundary line between the two electrodes and the component main body, which are unlikely to be detected, the mounting position and size of the mounted component can be accurately determined and a correct inspection can be performed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
According to a first aspect of the present invention, there is provided a method for inspecting a mounted component, wherein the plurality of electrodes and the component main body of the mounted component based on an image obtained by inputting a mounted printed circuit board surface portion, that is, a mounted state of the mounted component Mounting is performed by calculating the mounting position of the mounting component based on the information on the boundary line and the information on the position and size of the electrode regarding the mounting component that has been input in advance by teaching. A shape that includes information on a plurality of boundary line positions that are detected in the detection step of the boundary line in the process of determining whether the mounting position of the component is good and calculating the mounting position of the mounted part, and information on the electrodes of the mounted parts that are input in advance based on the information about, which to make the part contour calculation processing of calculating the outline of the mounting parts and features, the actual such precise chip components regardless of the state of soldering of components Recognizing the mounting position of the component, it is capable of proper inspection. In addition, for example, the outer shape is estimated by adding the electrode size taught in advance from the boundary line position between the two electrodes detected by the boundary line detection process and the component body, and the mounted component is determined from the estimated outer shape. Find the midpoint and use it as the mounting center position.
[0011]
In the mounting component inspection method according to claim 2 of the present invention, in the step of calculating the mounting position, the component that calculates the center position of the mounting component from the plurality of boundary line positions detected in the step of detecting the boundary line The center position calculation process is performed. For example, the midpoint of the boundary line position between the two electrodes and the component main body detected by the boundary line detection process is set as the center position in the direction along the electrode in the mounted component.
[0014]
(Embodiment 1)
FIG. 1 is a perspective view of a mounting component inspection apparatus according to an embodiment of the present invention. With this inspection apparatus, an operation for measuring the height of a printed circuit board surface portion and the amount of reflected light from the substrate surface is performed. FIG. 1 illustrates this principle. In addition, the same code | symbol is attached | subjected to the thing similar to a conventional one.
[0015]
As shown in FIG. 1, the inspection apparatus includes a laser unit 1 that irradiates a chip component (mounting component) 10 of a mounted printed board 2 that is a subject from above, and a chip component 10 of the printed board 2. Four position sensitive detectors (PSD) 4A, 4B, 4C, and 4D that receive the light reflected by the light source, and the surface shape of the printed circuit board 2 that is the subject based on the principle of triangulation Measure the data. In addition, a control means (not shown) having a storage function and an arithmetic function and performing processing to be described later is also provided. The position sensitive detectors 4A to 4D function as sensors that output two analog signals according to the position where the laser beam L is received.
[0016]
From the principle of triangulation, the irradiation source coordinates (X, Y, Z) of the laser beam L, the irradiation position coordinates (X, Y) on the subject, and the laser beam receiving coordinates (Xa, Y) in the position sensitive detectors 4A to 4D. The height coordinate at the irradiation position on the subject is calculated from (Ya, Za), (Xb, Yb, Zb), (Xc, Yc, Zc), and (Xd, Yd, Zd).
[0017]
The analog signal output from the position sensitive detectors 4A to 4D is converted based on the following equation (1) to calculate the height data of the subject. In the following formulas (1) and (2), H (x, y) indicates the height value measured at the sampling coordinate point (x, y) that is the irradiation position, and B (x, y) is It is a luminance value (reflection intensity) measured at the sampling coordinate point (x, y). Ia (x, y) and Ib (x, y) are signal values from the position sensitive detectors 4A to 4D measured at the sampling coordinate point (x, y). By adding the two signal values Ia (x, y) and Ib (x, y) that are output signals of the position sensitive detectors 4A to 4D, the luminance value (x, y) at the sampling coordinate point (x, y) ( B (x, y)) is represented.
H (x, y) = Ia (x, y) / (Ia (x, y) + Ib (x, y)) .. Formula 1
B (x, y) = Ia (x, y) + Ib (x, y).
The measurement of the surface shape data (height data) in the two-dimensional region of the subject is repeatedly performed by moving the subject in parallel in the X and Y planes with the sampling coordinate points fixed, or the subject is fixed Repeat by moving the sampling coordinate point in parallel.
[0018]
In addition, as a method of measuring surface shape data using a device other than the above, for example, a light cutting method that measures height data by changing slit light, or a stereo that measures height data from two or more parallax images It is also possible to acquire surface shape data from three-dimensional data measured by an X-ray computed tomography system (X-ray CT), a magnetic resonance imaging system (MRI), or the like.
[0019]
By these methods, it is possible to acquire a state where the chip component 10 as the mounting component is mounted on the printed circuit board 2 as the subject as a grayscale image and to recognize the height of the printed circuit board 2 on which the chip component 10 is mounted. An image can be obtained.
[0020]
Next, the inspection of the chip component position and the inspection of the chip component size are performed using the height image and the luminance image captured by the inspection apparatus. FIG. 2 is a flowchart showing this inspection process.
[0021]
First, in step ST10, the inspection apparatus measures height data and luminance data of the entire surface of the printed circuit board 2 on which components are mounted.
In step ST20, using the height data, a part edge detection process in a direction along the side having a short length in plan view (referred to as a short direction) is executed. FIG. 3 shows windows 31, 32, 333, and 34 for executing edge detection processing. The edge detection windows 31 to 34 are set to locations that are assumed not to be affected by the edge detection accuracy due to the soldering state, based on the information on the mounting positions of the printed circuit board 2 and the chip component 10 taught in advance. A change point of the height data in the windows 31 to 34 is detected and set as an edge point. From the data of the two edge points detected in the windows 31 and 32, the position of one side on the side where the solder is not attached (short direction) is obtained, and from the data of the two edge points detected in the windows 33 and 34 The position of the other side on the side where the solder is not attached (short direction) is obtained. The straight line connecting the midpoint of the two edge points detected in the windows 31 and 33 and the midpoint of the two edge points detected in the windows 32 and 34 is the center in the direction (longitudinal direction) where the solder is attached. The angle formed by the straight line portion viewed from the side of the center line A and the horizontal line is the component mounting rotation angle (mounting inclination angle).
[0022]
Next, in step ST30, the position of the boundary line between the electrodes 12, 13 and the component main body 11 is detected using the height data and the luminance data, and the longitudinal direction (component edge by soldering is detected based on the boundary line position. The edge of the part is detected. The longitudinal part edge detection processing will be described later.
[0023]
Next, in step ST40, the process of calculating the position and size of the chip component 10 is executed from the edge coordinates detected in steps ST20 and ST30.
Finally, in step ST50, with respect to the mounting position of the chip component 10, the amount of deviation between the mounting position of the chip component 10 calculated in step ST40 and the proper mounting position of the chip component 10 taught in advance is taught in advance. Whether or not the deviation is less than or equal to the allowable deviation value is compared. If the deviation amount is less than or equal to the allowable deviation value, it is determined to be a non-defective product, and if the deviation amount is greater than the allowable deviation value, it is determined to be defective.
[0024]
As for the component size, it is compared whether or not the difference between the size of the chip component 10 calculated in step ST40 and the size of the chip component 10 taught in advance is equal to or less than a pre-taught size allowable value. If the difference is equal to or smaller than the allowable size value, it is determined to be a non-defective product.
[0025]
Here, the part edge detection process in the longitudinal direction in step ST30 will be described in more detail. FIG. 4 is a flowchart showing the component edge detection processing step ST30 in the longitudinal direction.
[0026]
First, in step ST31, a processing target area is determined. FIG. 5 is a diagram showing a processing target region for executing the component edge detection processing in the longitudinal direction. Information regarding the mounting position of the chip component 10 taught in advance, component center position coordinates 41 which are information regarding the shape of the chip component 10, relative coordinates from the component center positions of the electrodes 12 and 13, and a component deviation allowable range 42 The two processing areas of the first processing target area 43 and the second processing target area 44 are determined for one chip component 10.
[0027]
In step ST32, the height image of the first processing target area 43 determined in step ST31 described above is read. In step ST33, the height image is binarized with a height threshold slightly lower than the height of the chip component 10 from which the component shape can be extracted, and the mask area is set to 0 and the non-mask area is set to 1. Generate an image.
[0028]
Next, in step ST34, the luminance image of the first processing target area 43 determined in step ST31 described above is read. In step ST35, an inter-image calculation is performed between the read luminance image and the mask processing area extracted in step ST34, and the boundary position detection processing area between the electrodes 12 and 13 and the component body 11 is narrowed down.
[0029]
Further, in step ST36, for example, a differential operator shown in FIG. 6 is applied to the luminance image subjected to the mask processing obtained in step ST35. Then, electrode body boundary detection processing for detecting a boundary line between the electrode 12 and the component body 11 is performed by obtaining a least square approximation line of coordinates indicating a value equal to or greater than a certain value in the processed image subjected to differentiation processing.
[0030]
In the present embodiment, the luminance image is differentiated from the electrode 12 and the component by a differential process in correspondence with the feature that the luminance image is high in the portion of the electrode 12 having a high amount of reflected light and low in the portion of the component main body 11 having a low amount of reflected light. Although the boundary line position with the main body 11 is detected, the contour line is extracted with respect to the image binarized by the threshold value that can extract only the electrode 12 in the masked luminance image obtained in step ST35. It is also possible to detect the boundary line between the electrode 12 and the component main body 11.
[0031]
Further, in step ST37, it is determined whether or not the process has been executed for the second processing target area 44 determined in step ST31. If not executed, the processing from step ST32 to step ST36 is executed for the second processing target region 44, and the first processing target region 43 and the second processing target region 44 determined in step ST31. The boundary line between the two electrodes 12 and 13 and the component main body 11 is detected for each of the processing areas.
[0032]
In step ST38, the outer edge coordinates of the chip component 10 are calculated based on the boundary line position between the two electrodes 12 and 13 and the component body 11 detected in step ST37 and the width of the electrodes 12 and 13 taught in advance. To do.
[0033]
As a result, the outer edge coordinates of the chip component 10 are calculated, and as described above, the processing for calculating the mounting position and size of the chip component 10 from the edge coordinates is executed in step ST40. Even when the electrodes 12 and 13 of the component 10 are covered, the mounting position and size of the chip component 10 can be accurately determined, and the correct inspection regarding the mounting position and size of the chip component 10 can be performed.
[0034]
In the above embodiment, the case where the electrodes 12 and 13 are provided at two locations on both sides of the component main body 11 is described. However, the present invention is not limited to this. The above inspection method can also be applied when there are electrodes at a plurality of end portions.
[0035]
【The invention's effect】
As described above, according to the present invention, the electrode of the mounting component is covered with the solder, and even when the end surface of the electrode outside the component or the corner of the mounting component cannot be recognized as in the conventional case, the solder is covered. By detecting the boundary line between the electrode and the component body at multiple locations that are unlikely to be detected, it is possible to accurately determine the mounting position and size of the mounting component such as a chip component, and to perform a correct inspection, thereby ensuring the reliability of the inspection Will improve.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of an inspection apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart showing an inspection method according to an embodiment of the present invention.
FIG. 3 is a diagram showing component edge detection processing in a short direction in the inspection method;
FIG. 4 is a flowchart showing part edge detection processing in the longitudinal direction in the inspection method.
FIG. 5 is a diagram showing a processing target area in the inspection method.
FIG. 6 is a view showing a mask pattern of a luminance image differentiation process in the inspection method.
FIG. 7A is a cross-sectional view of a chip component mounted on a printed circuit board and soldered.
(B) is the figure which looked at the soldered chip component from the upper surface.
(C) is the figure which showed the cross-sectional profile of the height data of the same chip component.
(D) is a figure which shows the image which binarized the chip component by the conventional inspection method.
8A and 8B show problems of a conventional inspection method, in which FIG. 8A is a cross-sectional view of a chip component, FIG. 8B is a plan view of a soldered chip component viewed from above, and FIG. (D) is a diagram showing an image obtained by binarizing the chip component.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Laser unit 2 Printed circuit board 4A-4D Position sensitive detector 10 Chip component (mounting component)
11 Component body 12, 13 Electrode 14, 15 Solder

Claims

Electrode is provided at each of a plurality of ends of the component body, and a mounting component inspection method for inspecting a mounting component soldered with the plurality of electrodes on a printed board,
The mounting state of the mounting component is input as an image, and boundary lines between the plurality of electrodes of the mounting component and the component main body are detected based on the input image, and information on these boundary lines and the mounting that is input in advance The mounting position of the mounting component is calculated based on the information related to the component, and the quality of the mounting state is determined based on the information on the mounting position of the mounting component and the appropriate mounting position input in advance .
In the step of calculating the mounting position of the mounting component, based on the plurality of boundary line positions detected in the detection step of the boundary line and the information on the shape including the information of the electrodes of the mounting component input in advance, A method for inspecting a mounted component, comprising performing a component outer shape calculation process for calculating an outer shape .

The component center position calculation process for calculating the center position of the mounted component from a plurality of boundary line positions detected in the step of detecting the boundary line is performed in the step of calculating the mounting position of the mounted component. The inspection method of the mounting components described.

In the step of inputting the mounting state of the mounted component as an image , the mounting state of the mounted component is input as an image by measuring the height of the surface portion of the mounted printed circuit board and the amount of reflected light from the surface of the mounted printed circuit board. The mounting component inspection method according to claim 1 .

Electrode is provided at each of a plurality of ends of the component body, and a mounting component inspection method for inspecting a mounting component soldered with the plurality of electrodes on a printed board,
The mounting state of the mounting component is input as an image, and boundary lines between the plurality of electrodes of the mounting component and the component main body are detected based on the input image, and information on these boundary lines and the mounting that is input in advance Calculate the size of the mounting component based on the information of the component, determine the quality of the mounting component based on the information of the size of the mounting component and the appropriate size input in advance ,
A method for inspecting a mounted component, comprising performing a component outer shape calculation process for calculating a component outer shape based on information on a component shape including information on electrodes of the mounted component in the step of calculating the size of the mounted component .

In the step of inputting the mounting state of the mounted component as an image , the mounting state of the mounted component is input as an image by measuring the height of the surface portion of the mounted printed circuit board and the amount of reflected light from the surface of the mounted printed circuit board. The method for inspecting a mounted component according to claim 4 .

Electrode is provided at each of a plurality of ends of the component body, and is a mounting component inspection apparatus that inspects a mounting component soldered to the printed circuit board with the plurality of electrodes,
Image input means for inputting the mounting state of the mounted component as an image, boundary line detecting means for detecting boundary lines between the plurality of electrodes of the mounted component and the component body based on the input image, and the boundary lines Based on the information on the mounting position, the mounting position calculating means for calculating the mounting position of the mounting component based on the information on the mounting component and the information on the mounting component input in advance, and the information on the mounting position of the mounting component and the appropriate mounting position input in advance Determination means for determining the quality of the mounting state ,
The mounting position calculation means calculates the outer shape of the mounting component based on a plurality of boundary line positions detected by the boundary line detection means and information relating to the shape including information on the electrodes of the mounting component input in advance. A device for inspecting mounted parts.

The mounting component inspection apparatus according to claim 6 , wherein the mounting position calculation unit calculates a center position of the mounting component from a plurality of boundary line positions.

The mounted component according to claim 6 , wherein the image input unit includes a measuring unit that measures a height of a surface portion of the mounted printed circuit board and a reflected light amount from the surface of the mounted printed circuit board. Inspection device.

Electrode is provided at each of a plurality of ends of the component body, and is a mounting component inspection apparatus that inspects a mounting component soldered to the printed circuit board with the plurality of electrodes,
Image input means for inputting the mounting state of the mounted component as an image, boundary line detecting means for detecting boundary lines between the plurality of electrodes of the mounted component and the component body based on the input image, and the boundary lines Size calculating means for calculating the size of the mounting component based on the information on the mounting component and information on the mounting component input in advance, and information on the mounting component based on the information on the size of the mounting component and the appropriate size input in advance Determination means for determining pass / fail ,
The size calculation means calculates a component external shape based on information on a component shape including information on electrodes of the mounted component, and a mounting component inspection apparatus characterized by the following.

The mounted component according to claim 9 , wherein the image input unit includes a measuring unit that measures a height of a surface portion of the mounted printed circuit board and a reflected light amount from the surface of the mounted printed circuit board. Inspection device.