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Inspection and manufacture method of thin film magnetic head

一种检测薄膜、薄膜磁头的技术，应用在使用薄膜的磁头、磁头的功能测试、磁场的大小/方向等方向，能够解决难制造薄膜磁头等问题

Inactive Publication Date: 2005-02-23
TDK CORPARATION +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, it is difficult to manufacture thin film magnetic heads processed by various thin film processes, and thus defective products with poor characteristics are sometimes produced

Method used

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  • Inspection and manufacture method of thin film magnetic head
  • Inspection and manufacture method of thin film magnetic head
  • Inspection and manufacture method of thin film magnetic head

Examples

Experimental program
Comparison scheme
Effect test

no. 1 example

[0105] First of all, refer to Figure 4 to 9 , Will explain the results of the asymmetric features in each of the QSTs mentioned above. The next result refers to the thin film magnetic head formed in one of the multiple stripes.

[0106] Figure 4 The abscissa and ordinate show the measurement results of QST1 and QST2, respectively. That is, this graph shows the asymmetrical change between before and after applying a DC magnetic field. Although it is ideal if the asymmetric value remains the same before and after loading an external magnetic field, etc. (that is, it is preferred if the marked points are concentrated on a line), from this figure we can see that the DC is loaded The asymmetric fluctuations between before and after the magnetic field are large. Therefore, the number of asymmetric changes is large.

[0107] Figure 5 The abscissa and ordinate show the measurement results of QST2 and QST3, respectively. That is, this graph shows the asymmetric change between before a...

no. 2 example

[0113] reference Figure 10 to 15 , Will explain the results of the copy output in each of the QSTs mentioned above.

[0114] Picture 10 The abscissa and ordinate show the measurement results of QST1 and QST2, respectively. That is, this picture shows the change in the replication output between before and after applying a DC magnetic field in step 2. Although it is ideal if the value of the copied output remains unchanged before and after loading an external magnetic field, etc., from this figure we can see that the copied output fluctuates greatly before and after loading a DC magnetic field.

[0115] Picture 11 The abscissa and ordinate show the measurement results of QST2 and QST3, respectively. That is, this graph shows the change in the replication output between before and after loading an AC magnetic field. In this case, you can also see that there are fluctuations in the copied output value everywhere. From this result, it can be found that if a DC magnetic field is a...

no. 3 example

[0121] reference Figure 16 to 19 Now, the MR cycle characteristics of the GMR film measured in each QST will be explained.

[0122] Figure 16 The MR cycle characteristics of the GMR film in QST1 are shown. The MR cycle characteristic represents the head output voltage with respect to the external magnetic field. The abscissa and ordinate indicate the external magnetic field (Oe) and the copy output voltage (μV), respectively. It can be seen from the figure that before the external magnetic field is applied, the output voltage of the copy is too low, so it cannot reach the predetermined standard.

[0123] Figure 17 The MR cycle characteristics in QST2 are shown. The form of the MR cycle characteristic in this example is the same as that before the DC magnetic field is applied. Figure 16 Compared with the indicated state, there is a big change and conforms to the standard.

[0124] Figure 18 It shows the MR cycle characteristics in QST3. This result shows the characteristics...

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Abstract

In the method of inspecting a thin-film magnetic head, a thin-film magnetic head provided with a magnetoresistive film having a free layer whose magnetization direction changes depending on an external magnetic field and ferromagnetic layers for applying a bias magnetic field to the free layer is prepared. Then, a DC magnetic field is applied to the ferromagnetic layers in the bias magnetic field applying direction. Subsequently, an AC magnetic field is applied to the ferromagnetic layers in the bias magnetic field applying direction. Thereafter, an external magnetic field is applied to the magnetoresistive film while supplying a current thereto, and a property of the thin-film magnetic head such as asymmetry and reproducing output is inspected.

Description

[0001] Related application [0002] The entire contents of Japanese Patent Application No. 2003-294522 filed on August 18, 2003 and Japanese Patent No. 2003-309106 filed on September 1, 2003 are hereby incorporated by reference into this application. Technical field [0003] The invention relates to a method for detecting a thin film magnetic head and a method for manufacturing a thin film magnetic head. Background technique [0004] Generally, a thin-film magnetic head installed in a hard disk drive or the like includes a magnetoresistive film and a pair of hard bias layers (ferromagnetic layers). The magnetoresistive film has a free layer whose magnetization direction changes based on an external magnetic field. The placement layer applies a bias magnetic field to the free layer to obtain a single domain with a magnetization direction (for example: Japanese published patent application HEI10-242544). Under the influence of an external magnetic field from a hard disk (recording m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R33/06G01R33/12G11B5/31G11B5/39G11B5/455
CPCG11B5/3903G11B5/455G11B5/3166G11B5/3116
Inventor 松隈裕树小桥宗顺
Owner TDK CORPARATION
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