JPH0296655A - Improvement of sensitivity of magnetic sensor - Google Patents
Improvement of sensitivity of magnetic sensorInfo
- Publication number
- JPH0296655A JPH0296655A JP63247374A JP24737488A JPH0296655A JP H0296655 A JPH0296655 A JP H0296655A JP 63247374 A JP63247374 A JP 63247374A JP 24737488 A JP24737488 A JP 24737488A JP H0296655 A JPH0296655 A JP H0296655A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic sensor
- magnetic
- fore end
- distance
- magnetism
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 90
- 230000035945 sensitivity Effects 0.000 title claims description 8
- 239000000463 material Substances 0.000 claims abstract description 17
- 238000001514 detection method Methods 0.000 claims abstract description 16
- 230000005389 magnetism Effects 0.000 claims abstract description 16
- 239000011347 resin Substances 0.000 claims abstract description 6
- 229920005989 resin Polymers 0.000 claims abstract description 6
- 230000007547 defect Effects 0.000 claims description 22
- 239000000758 substrate Substances 0.000 abstract description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 abstract description 5
- 229910052710 silicon Inorganic materials 0.000 abstract description 5
- 239000010703 silicon Substances 0.000 abstract description 5
- 238000003754 machining Methods 0.000 abstract 1
- 238000007689 inspection Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 2
- 230000005294 ferromagnetic effect Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 244000309464 bull Species 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000002516 single-drop micro-extraction Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
- Measuring Magnetic Variables (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、鋼板の欠陥検査に用いる磁気探傷装置の欠陥
検出能力向上に関するもので磁気探傷装置に使用してい
る磁気センサーの先端部分を研削加工し、感磁素子面を
できるだけ被検材に近づけ被検材表面の極く近傍に存在
する微小漏ｆｉ磁気を検出できるようにした磁気センサ
ーを提供することに有る。Detailed Description of the Invention (Industrial Field of Application) The present invention relates to improving the defect detection ability of a magnetic flaw detection device used for defect inspection of steel plates. The object of the present invention is to provide a magnetic sensor which is processed so that the surface of the magnetic sensing element is brought as close as possible to the material to be tested so as to be able to detect minute leakage fi magnetism existing very close to the surface of the material to be tested.
（従来の技術）
市販の磁気センサー、例えばソニー製Ｄ Ｍ １０６Ｂ
等は１位置検出や導磁性体の検出等に使われるが、検出
対象となる磁気が強いため、磁気センサーの形状や被測
定物との間隙等使用条件を特別に考慮して使わなくても
初期の目的を達成できることが多い。(Prior art) Commercially available magnetic sensor, for example Sony DM 106B
etc. are used for single-position detection, detection of magnetically conductive materials, etc., but because the magnetism to be detected is strong, there is no need to take special consideration to usage conditions such as the shape of the magnetic sensor and the gap between it and the object to be measured. Initial objectives can often be achieved.
（解決しようとする課題）
検査装置における欠陥検出能力の優劣はセンサーによっ
て決まると言って過言でない、磁気探傷においてもこれ
は例外でなく、微小な欠陥を検出しようとする場合高感
度な磁気センサーを選択することは特に重要な課題であ
る。（磁気センサーニツイテは１９８０年６月発行（７
）ＭＥＣＨＡＴＲＯＮＩＣ３−Ｐ。(Problem to be solved) It is no exaggeration to say that the defect detection ability of inspection equipment is determined by the sensor. This is no exception in magnetic flaw detection, and when trying to detect minute defects, a highly sensitive magnetic sensor is required. Selection is a particularly important issue. (Magnetic sensor website was published in June 1980 (7
) MECHATRONIC3-P.
７「磁気センサ“ＳＤＭＥ″′の原理と応用（１）Ｊに
記載がある。）高感度な磁気センサーとして例えばソニ
ー製磁気センサーＤＭ１０６Ｂが有るが、この磁気セン
サーは強磁性金属薄膜を感磁素子として使用しているも
ので、磁気に対する感度は磁気センサーの飽和磁場近辺
の低磁場で比較するとホール素子の数十〜数百倍有り、
しかも、温度特性が良い等価れた特性を持つ磁気センサ
ーである。7 "Principle and application of magnetic sensor "SDME"' (1) Described in J.) As a highly sensitive magnetic sensor, for example, there is the Sony magnetic sensor DM106B, which uses a ferromagnetic metal thin film as a magnetic sensing element. The sensitivity to magnetism is tens to hundreds of times higher than that of Hall elements when compared in low magnetic fields near the saturation magnetic field of the magnetic sensor.
Moreover, it is a magnetic sensor with equivalent characteristics and good temperature characteristics.
しかしこの磁気センサーを用いて検査装置を構成し欠陥
の検出試験を行うと、当該磁気センサーと磁気的感度だ
けを見ると同等の性能を有する別の磁気センサー、例え
ばソニー製半導体磁気センサーＭＤ１３０Ｇを、前記Ｄ
Ｍ１０６Ｂと機械的な配置と被検材とのギャップ量およ
び磁化力等、試験条件を全て同一にして使用した場合と
比較すると欠陥の検出能力、特に微小な欠陥の検出能力
が極端に悪くなるという問題がある。However, when an inspection device is configured using this magnetic sensor and a defect detection test is performed, another magnetic sensor with the same performance as the magnetic sensor, such as Sony's semiconductor magnetic sensor MD130G, is used. Said D
Compared to using M106B under the same test conditions, such as the gap between the mechanical arrangement, the amount of gap between the test material, and the magnetizing force, the ability to detect defects, especially the ability to detect minute defects, is said to be extremely poor. There's a problem.
これは二つの磁気センサーの構造的な相違によるもので
、微小な欠陥からの漏洩磁気は被検材表面の極く近傍に
しか生じないため、感磁素子が磁気センサーの表面に配
置されているＭＤ１３０Ｇでは被検材表面の極く近傍に
生じる微小漏洩磁気を検出できるが、感磁素子が磁気セ
ンサーの表面からやや離れた所に配置されているＤＭ１
０６Ｂでは被検材表面の極く近傍にある微小漏洩磁気の
位置迄、感磁素子が到達していない為検出できないこと
になる。この為、磁気的な感度は充分高いにもかかわら
ず、市販の形状のままではソニー製磁気センサーＤＭ１
０６Ｂは微小欠陥の検出には適さない。This is due to the structural difference between the two magnetic sensors. Magnetic leakage from minute defects occurs only in the very vicinity of the surface of the material being tested, so the magnetic sensing element is placed on the surface of the magnetic sensor. The MD130G can detect minute leakage magnetism that occurs very close to the surface of the material being tested, but the DM1, whose magnetic sensing element is located a little farther from the surface of the magnetic sensor,
In 06B, the magnetic sensing element does not reach the position of the minute leakage magnetism that is very close to the surface of the material to be tested, so it cannot be detected. For this reason, although the magnetic sensitivity is sufficiently high, the Sony magnetic sensor DM1 cannot be used in its commercially available form.
06B is not suitable for detecting minute defects.
（課題を解決するための手段）
本発明は被検材を電磁石で磁化し欠陥から生じる漏洩磁
気を検出して欠陥の検査を行う磁気探傷方法において、
磁気探傷装置に使用している磁気センサーの樹脂モール
ド層の先端部分を研削し、磁気センサー先端から磁気セ
ンサーの樹脂モールド内にある感磁素子面までの間隔を
できるだけ小さくし結果として、被検材と感磁素子面と
の距離を小さくすることにより、被検材表面の極く近傍
に漏洩している微小欠陥からの微小磁気を検出できるよ
うに加工する磁気センサーの感度向上方法である。(Means for Solving the Problems) The present invention provides a magnetic flaw detection method for inspecting defects by magnetizing a material to be inspected with an electromagnet and detecting leakage magnetism generated from defects.
The tip of the resin mold layer of the magnetic sensor used in magnetic flaw detection equipment is ground to minimize the distance between the tip of the magnetic sensor and the surface of the magnetically sensitive element inside the resin mold of the magnetic sensor. This is a method of improving the sensitivity of a magnetic sensor by reducing the distance between the surface of the magnetic sensor and the surface of the magnetic sensing element so that it can detect minute magnetism from minute defects leaking very close to the surface of the material to be inspected.
以下本発明を図示の実施例にもとずいて詳細に説明する
。第１図はソニー製磁気センサーＤＭ１０６Ｂの構造略
図である。第１図に示す磁気センサーの構造は、当該磁
気センサーを分解調査して把握したもので、磁気センサ
ーはモールド層１、硅素基板２、電極３、感磁素子４お
よび端子５から構成されている。磁気センサーの先端か
ら感磁素子４までの距離は、第１図に示す通り、磁気セ
ンサーのモールドＭ１の先端から硅素基板２の先端まで
がａ：３００μｍ〜４００μｍ、硅素基板２の先端から
電極３の先端までがｂ：１００μ燻〜１５０μｍ、電極
３の先端から感磁素子までがＣニア０μ＋１〜９０μｍ
有り、磁気センサー先端から磁気素子４までは５００μ
ｍ以上の間隔が有ることが分る。The present invention will be explained in detail below based on the illustrated embodiments. FIG. 1 is a schematic diagram of the structure of the Sony magnetic sensor DM106B. The structure of the magnetic sensor shown in Fig. 1 was determined by disassembling the magnetic sensor and is composed of a mold layer 1, a silicon substrate 2, an electrode 3, a magnetic sensing element 4, and a terminal 5. . As shown in FIG. 1, the distance from the tip of the magnetic sensor to the magnetic sensing element 4 is 300 μm to 400 μm from the tip of the mold M1 of the magnetic sensor to the tip of the silicon substrate 2, and the distance from the tip of the silicon substrate 2 to the electrode 3 is 300 μm to 400 μm. From the tip of electrode 3 to the tip of B: 100 μm to 150 μm, from the tip of electrode 3 to the magnetic sensing element C near 0 μ+1 to 90 μm
Yes, distance from the tip of the magnetic sensor to magnetic element 4 is 500μ
It can be seen that there is an interval of m or more.
一方、欠陥からの漏洩磁気は被検材表面からの距離が増
すと指数関数的に減少することが知られており、第２図
に示すグラフの例は、第１図に示す磁気センサーをまず
電極３が出るまで削り込み電極３が露出後さらにｄ：５
０μ醜を注意深く削込んだ磁気センサーを使用して、５
ＸＩＯ−’〜１０ Ｘ １０−’ｍｍ３ の体積を有す
る５種類の欠陥を被検材と磁気センサーとのギャップ量
を種々変えて検出試験を行い５種類の欠陥信号電圧の平
均値をギャップ量１００μ踊の時の信号電圧で基準化し
てプロットしたもので、ギャップ量の増加と共に信号電
圧が小さくなっているのが分る。On the other hand, it is known that magnetic leakage from defects decreases exponentially as the distance from the surface of the test material increases. Scrape until electrode 3 comes out, and then further d:5 after electrode 3 is exposed.
Using a magnetic sensor with carefully carved 0μ ugliness, 5
Detection tests were conducted for five types of defects having a volume of XIO-'~10 x 10-'mm3 by varying the gap amount between the test material and the magnetic sensor, and the average value of the five types of defect signal voltages was calculated based on the gap size of 100μ. This plot is normalized to the signal voltage during the dance, and it can be seen that the signal voltage decreases as the gap amount increases.
すなわち、微小欠陥からの漏洩磁気は被検材表面の極く
近傍に発生していることが、このデータでも裏付けられ
ており、微小欠陥を磁気探傷装置で検出しようとする場
合、第１図に示すような構造の磁気センサーをそのまＳ
使用したのでは磁気センサー先端から感磁素子面までの
５００μＩ以上有る間隔がもろに効いて、磁気に対する
感度自体は非常に高い磁気センサーでも磁気の存在する
位置まで感磁素子面が到達できないため検出能力は著し
く悪いという結果になる。そこで本発明の如く磁気セン
サー先端部分を加工し磁気センサー先端から感磁素子面
までの間隔が７０〜９０μｍ程度になるまで研削して使
用すれば、被検材表面の極く近傍に漏洩する微小磁気を
検出できるようになり上述の問題は解決できる。In other words, this data supports the fact that magnetic leakage from minute defects occurs very close to the surface of the material to be inspected. A magnetic sensor with the structure shown is S as is.
When used, the distance of 500μI or more from the tip of the magnetic sensor to the surface of the magnetic sensing element is effective, and even though the magnetic sensor itself has very high sensitivity to magnetism, the surface of the magnetic sensing element cannot reach the position where the magnetism exists, so it can be detected. The result is that the performance is significantly worse. Therefore, if the tip of the magnetic sensor is processed and ground until the distance from the tip of the magnetic sensor to the surface of the magnetic sensing element is approximately 70 to 90 μm as in the present invention, it is possible to reduce the Magnetism can now be detected and the above problems can be solved.
（作用）
本発明による高感度磁気センサーについて説明する。第
３図は、第１図に示す磁気センサーの構造にある研削加
工位置での磁気センサーの型別に試験の結果を示したも
ので、横軸は磁気センサーの型式、縦軸は検出信号電圧
である。無加工の０型センサーでは検出できなかった微
小欠陥からの漏洩磁気を磁気センサー先端から約４００
μ騰研削した１型で検出し始め、１型からさらに約１５
０μ■研削した２型でＳ／Ｎ比的に実用レベルに達した
。２型からさらに約５０μｍ、研削した３型は２型に比
較して当然感度は高くなるが素子の酸化により耐久性に
問題が有り、２型が実用的で現在この２型の磁気センサ
ーを用いた検査装置で検査を行なっているがトラブルも
なく順調に稼働している。(Function) The highly sensitive magnetic sensor according to the present invention will be explained. Figure 3 shows the test results for each type of magnetic sensor at the grinding position in the magnetic sensor structure shown in Figure 1, where the horizontal axis is the magnetic sensor type and the vertical axis is the detection signal voltage. be. Magnetic leakage from minute defects that could not be detected with an unprocessed type 0 sensor is detected by approximately 400 mm from the tip of the magnetic sensor.
It started to be detected with the 1st type which was grinded, and about 15% more from the 1st type.
The S/N ratio of Type 2, which was ground to 0μ■, reached a practical level. Type 3, which is ground approximately 50 μm further than type 2, naturally has higher sensitivity than type 2, but there is a problem with durability due to oxidation of the element, so type 2 is the most practical magnetic sensor, and currently this type 2 magnetic sensor is used. The inspection is being carried out using the inspection equipment that was used, and it is operating smoothly without any trouble.
（発明の効果）
微小欠陥を検出するために磁気に対する感度が非常に高
い磁気センサーを使用しても欠陥から漏洩する磁気の存
在する位置に感磁素子が到達しなければ全く用を無さず
、本発明の如くセンサー先端を研削加工することにより
感磁素子面を被検材に近づければ、被検材表面の極く近
傍に存在する漏洩磁気を検出できる高感度な磁気センサ
ーとなり、磁気探傷装置の検出能力向上に寄与するとこ
ろ大である。(Effect of the invention) Even if a magnetic sensor with extremely high sensitivity to magnetism is used to detect minute defects, it is of no use unless the magnetic sensing element reaches the position where the magnetism leaking from the defect exists. By grinding the tip of the sensor as in the present invention to bring the surface of the magnetic sensing element closer to the material being tested, it becomes a highly sensitive magnetic sensor that can detect magnetic leakage that exists very close to the surface of the material being tested. This greatly contributes to improving the detection ability of flaw detection equipment.
第１図は磁気センサーの構造断面図、
第２図はギャップ量に対する信号電圧の特性値のグラフ
、
第３図は磁気センサーの型式別の信号電圧値のグラフで
ある。
１・・・モールド層 ２・・・硅素基板３・・・電
極 ４・・強磁性感磁素子５−１〜５−３・
・・端子
第１図
第２図
ギヤ、ブｌ［ｐｍｌ
５−１〜５−３＝端子FIG. 1 is a cross-sectional view of the structure of the magnetic sensor, FIG. 2 is a graph of the characteristic value of signal voltage versus gap amount, and FIG. 3 is a graph of signal voltage values for each type of magnetic sensor. DESCRIPTION OF SYMBOLS 1...Mold layer 2...Silicon substrate 3...Electrode 4...Ferromagnetic magnetosensitive elements 5-1 to 5-3.
...Terminal Figure 1 Figure 2 Gear, Bull [pml 5-1 to 5-3 = terminal
Claims (1)
して欠陥の検査を行う磁気探傷方法において、磁気探傷
装置に使用している磁気センサーの樹脂モールド層の先
端部分を研削し、磁気センサー先端から磁気センサーの
樹脂モールド内にある感磁素子面までの間隔を７０μｍ
〜９０μｍにし結果として、被検材と感磁素子面との距
離を小さくすることにより被検材表面の極く近傍に漏洩
している微小欠陥からの微小磁気を検出できるように加
工する磁気センサーの感度向上方法。In the magnetic flaw detection method, which inspects defects by magnetizing the test material with an electromagnet and detecting leakage magnetism generated from defects, the tip of the resin mold layer of the magnetic sensor used in the magnetic flaw detection device is ground, and the magnetic sensor The distance from the tip to the magnetic sensing element surface inside the resin mold of the magnetic sensor is 70 μm.
~90 μm, and as a result, by reducing the distance between the test material and the magnetic sensing element surface, a magnetic sensor is processed to be able to detect minute magnetism from micro defects leaking very close to the test material surface. How to improve sensitivity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63247374A JPH0296655A (en) | 1988-10-03 | 1988-10-03 | Improvement of sensitivity of magnetic sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63247374A JPH0296655A (en) | 1988-10-03 | 1988-10-03 | Improvement of sensitivity of magnetic sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0296655A true JPH0296655A (en) | 1990-04-09 |
Family
ID=17162480
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63247374A Pending JPH0296655A (en) | 1988-10-03 | 1988-10-03 | Improvement of sensitivity of magnetic sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0296655A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6544681B2 (en) | 2000-12-26 | 2003-04-08 | Ballard Power Systems, Inc. | Corrugated flow field plate assembly for a fuel cell |
| JP2007187572A (en) * | 2006-01-13 | 2007-07-26 | Asahi Kasei Corp | Measuring instrument using magnetic sensor and measuring method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5851580A (en) * | 1981-09-24 | 1983-03-26 | Hitachi Ltd | Magnetic detection sensor |
-
1988
- 1988-10-03 JP JP63247374A patent/JPH0296655A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5851580A (en) * | 1981-09-24 | 1983-03-26 | Hitachi Ltd | Magnetic detection sensor |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6544681B2 (en) | 2000-12-26 | 2003-04-08 | Ballard Power Systems, Inc. | Corrugated flow field plate assembly for a fuel cell |
| JP2007187572A (en) * | 2006-01-13 | 2007-07-26 | Asahi Kasei Corp | Measuring instrument using magnetic sensor and measuring method |
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