KR20010001338A - Method for manufacturing of thin-film laminated type micro-coil - Google Patents

Abstract

PURPOSE: A manufacturing method of a thin film depositing type microcoil is provided to easily deposit coils of two or more layers while keeping a flatness. CONSTITUTION: A plating base layer is formed on a substrate(111). The plating base layer is patterned correspondingly to the shape of a coil(121`) to be plated. A mold is spread on the patterned plating base layer(115`) to a predetermined height. The mold is patterned to form a plating mold(119`). A metal is plated in the plating mold(119`) to form a coil(121`) having a predetermined thickness. An insulating layer(123) is formed on the plating mold(119`) and the coil(121`). A plating base layer(125) is formed on the insulating layer. The plating base layer is patterned correspondingly to the shape of a coil(131) to be plated. A mold is spread on the patterned plating base layer(125`) and patterned to form a plating mold. A metal is plated in the plating mold(129) to form a coil(131) having a predetermined thickness. The plating mold is subjected to a heat treatment.

Description

Method for manufacturing of thin-film laminated type micro-coil

The present invention relates to a method for manufacturing a thin film multilayer microcoil having a structure of laminating microcoils. It relates to a microcoil manufacturing method.

In general, the thin film multilayer microcoil is intended to be used as a magnetic field modulation coil of a magneto-optical head for near field recording / reproducing, and has a two-layer structure or more stacked structure to increase the magnetic field in a limited space. There is this. That is, when employed in the near field recording method, the microcoil plays a role in generating a magnetic field for causing magnetization in the up and down directions at a point of the recording medium heated above the Curie temperature by a laser beam passing through a hole formed in the center of the coil. do.

1 is an exploded perspective view showing a general thin film multilayer micro coil, illustrating a two-layer structure as an example. The first layer coil 20 is spirally wound in a predetermined direction and is electrically insulated by the first insulator 10. The first layer coil 20 has first and second contacts 21 and 23 for electrical connection with the second layer coil 50 and the first electrode 55 which will be described later. The second layer coil 50 is laminated on the first coil while being insulated by the second insulating layer 30 interposed with the first layer coil 20. The second layer coil 50 is spirally wound in the same direction as the first layer coil 20 and is electrically insulated by the interposed second insulator 40. The second layer coil 50 has a third contact 51 electrically connected to the first contact 21 and a fourth contact 53 for electrical connection with the second electrode 57 to be described later. Have Each of the first and second electrodes 55 and 57 has a wide electrical contact surface to which a current is applied.

As described above, when the current is applied through the first and second electrodes 55 and 57, the configured thin film multilayer microcoil may have the first and second layer coils 20 and 50 wound in a spiral shape in the same direction. Through the current is applied to form a magnetic field. The magnetic field formed is modulated in accordance with the direction of the applied current.

A thin film multilayer microcoil having a structure as described above was conventionally manufactured by a process as disclosed in FIGS. 2A to 2H.

First, as shown in FIG. 2A, a first plating base layer 65 is deposited on the substrate 61 for plating deposition of the first layer coil. After coating the plating mold with a predetermined height on the first plating base layer 65, the plating mold is patterned into a negative shape corresponding to the shape of the first layer coil to complete the first plating frame 67. . The adhesive layer 63 is first deposited on the substrate 61 in consideration of adhesiveness when the adhesive is adhered to the insulating layer of the substrate 61, and then the first plating base layer 65 is deposited.

As described above, after the first plating base layer 65 and the first plating frame 67 are provided, the first layer coil is formed in the first layer coil plating groove 69 by plating, as shown in FIG. 2B. 20) is deposited.

Then, as shown in Figure 2c, the first plating frame 67 is removed through an etching process. In this case, all the conductors of the first layer coil 20 are electrically connected to each other through the first plating base layer 65. In order to prevent this, as shown in FIG. 2D, the first plating base layer 65 disposed on the bottom surface of the first etching groove 71 is removed to form the first removal part 73.

Looking at the process for forming the coil of the second layer for the thin film coil of one layer manufactured through the above process as follows.

The foundation for forming the second layer coil is formed by applying the insulating layer 75 for electrical insulation on the first removing unit 73 and the first layer coil 20. That is, as shown in FIG. 2E, the shape of the insulating layer 75 after coating is not uniform due to the step height between the plated first layer coil 20 and the first etching groove 71. Will not. In this case, the first and second contact holes 75a and 75b of the first layer coil 10 are formed in the insulating layer 75 for electrical connection with the second layer coil, which will be described later. Form.

Thereafter, as shown in FIG. 2F, the second plating base layer 77 is deposited on the insulating layer 75, and then a plating mold is applied to the second plating base layer 77 at a predetermined height. Thereafter, the plating mold is patterned into a negative shape corresponding to the shape of the second layer coil to complete the second plating frame 79. Here, when the second plating base layer 77 is formed, it is also deposited in the first and second through holes 75a and 75b so that the first and second through holes 75a and 75b may be respectively formed in the first and second through holes 75a and 75b. Second conducting portions 77a and 77b are formed.

As shown in FIG. 2G, the second layer coil 50 is deposited by plating on the second layer coil plating groove 81 formed by the patterning of the second plating frame 79. Thereafter, the second plating mold 79 is removed through an etching process. Since the height of the insulating layer 77 is not constant, the thickness of the conductive wire of the second layer coil 50 formed as described above is not constant. Then, as shown in Figure 2h, by removing the second plating base layer 77 located on the bottom surface of the second etching groove 83 to form a second removal portion 85, the two-layer coil is completed.

When the thin film multilayer microcoil is manufactured by the above-described process and the height of the insulating layer is not constant and has a step, there are concerns that the following two aspects may occur. First, since the insulating layer is not flat, when the second plating frame is formed by the photolithography process after the second plating base layer is formed, contact between the mask and the second plating base layer or a depth exceeding the focal depth of the optical system for the exposure is increased. Etc., there is a problem that the resolution of the pattern is lowered. Second, when the second plating base layer is deposited when there is a step of steep slope, the metal forming the second plating base layer is broken at the stepped portion.

Due to these problems, constraints occur in the line width of the second layer coil, the spacing between the coils, and the coil heights of the stacked layers. This problem is intensified as the number of coils is increased, which limits the manufacturing of multilayer coils.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and provides a method for manufacturing a thin film multilayer microcoil, which is capable of facilitating stacking of two or more coils by maintaining flatness of a substrate even after forming a coil of one layer. The purpose is.

1 is an exploded perspective view schematically showing a typical thin film multilayer microcoil.

Figures 2a to 2h each illustrate a conventional thin film laminated microcoil manufacturing process.

Figures 3a to 3k each show a thin film laminated microcoil manufacturing process according to an embodiment of the present invention.

<Explanation of symbols for main parts of drawing>

111 substrate 113 first insulating layer

115, 115 '... 1st plating base layer 117 ... first insulation groove

119, 119 '... 1st plating frame 121 ... 1st coil

123 ... Secondary insulation layer 125, 125 '... Second plating base layer

127 2nd insulation groove 129, 129 '2nd plating frame

131.2nd coil

According to an aspect of the present invention, there is provided a method of manufacturing a thin film multilayer microcoil, comprising: forming a plating base layer on a substrate; Patterning the plating base layer corresponding to the shape of the coil to be plated; Applying a mold to a predetermined height on the patterned plating base layer, and then patterning the mold to form a plating mold; Plating a metal between the plating molds to form a coil with a predetermined thickness; Forming an insulating layer on the plating mold and the coil; Including, the insulating layer is characterized in that it can maintain the flatness.

Further, the plating base layer forming step, the plating substrate layer patterning step, the plating mold forming step, and the coil forming step are sequentially repeated on the insulating layer at least one or more times in order to maintain the flatness between the coils. It is characterized in that the coils of the layers are laminated in multiple layers.

Hereinafter, a method of manufacturing a thin film multilayer microcoil according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3A to 3K illustrate a process of manufacturing a two-layer thin film multilayer microcoil having a structure as shown in FIG. 1.

First, as shown in FIG. 3A, the first plating base layer 115 is formed on the prepared substrate 111. The substrate 111 is, for example, a silicon substrate and has a structure in which an insulating film such as a silicon oxide film is deposited on the upper surface thereof. The first plating base layer 115 is a layer for plating deposition of the first layer coil, and is formed by vacuum depositing a material having excellent electrical conductivity such as copper. Here, the adhesive layer 113 made of chromium, titanium, or the like is first deposited on the substrate 111 in consideration of adhesiveness when the first plating base layer 115 is deposited on the insulating layer of the substrate 61. After that, it is preferable to deposit the first plating base layer 115.

As shown in FIG. 3B, the first plating base layer 115 is patterned to correspond to the shape of the first layer coil to be plated (121 of FIG. 3D). That is, the first insulating groove 117 is formed by removing the first plating base layer 115 in a portion opposite to the first plating frame 119 of FIG. 3C to be described later. This is to maintain the flatness of the insulating layer that is the base of the second layer coil by manufacturing the micro coil without removing the first plating frame 119.

Subsequently, as shown in FIG. 3C, a mold is applied to the patterned first plating base layer 115 ′ at a predetermined height, and then the mold is formed into a negative shape corresponding to the shape of the first layer coil 121. The plating mold is patterned to complete the first plating frame 119. Here, since the first plating base layer 115 'is a thin film having a thickness of about 1000 mm, plating is performed when the plating mold is applied to the entire patterned first plating base layer 115' by the same method as spin coating. The upper surface of the mold for maintaining the flatness. The first plating frame 119 is made of an insulating material such as photoresist. In this case, there is an advantage that the patterning is possible with one photo etching.

Thereafter, as illustrated in FIG. 3D, a metal is plated between the first plating frames 119 formed by patterning to form a first layer coil 121 having a spiral structure having a predetermined line width to a predetermined thickness. Here, since the first layer coil 121 is used for flowing a large amount of current, it is preferable to form the first layer coil 121 by plating because it is a relatively thick metal film. As the plating method, both the electroplating method and the electroless plating method can be used.

Subsequently, as illustrated in FIG. 3E, the first plating mold 119 is heat treated. This is to completely remove the solvent remaining in the first plating mold 119, thereby minimizing thermal deformation of the heat treated first plating mold 119 '. Here, when the heat treatment step is performed, the height of the first plating layer 119 ′ is lowered. Therefore, when the thickness of the first layer coil 121 is the same as the height of the first plating frame 119, after the heat treatment step, the upper surface of the first plating frame 119 'and the first layer The upper surfaces of the coils 121 may be stepped on each other.

In consideration of this, as shown in FIG. 3D, it is preferable to form the height of the first plating frame 119 relatively higher than the thickness of the first layer coil 121. For example, when the height of the first plating frame 119 ′ after the heat treatment is lowered by about 70% compared to the height before the heat treatment, the height of the first plating frame 119 may be compared to the thickness of the first layer coil 121. If the height is approximately 140%, the height of the upper surface of the first plating frame 119 ′ and the first layer coil 121 after the heat treatment step may be similarly or equally matched as illustrated in FIG. 3E.

The heat treatment is possible through an oven, a plate heating device, an ultraviolet curing device, an electron beam heat treatment device, and the like.

Next, as shown in FIG. 3F, the first layer coil 121 and the second layer coil (131 of FIG. 3J) are described on the upper surfaces of the first plating frame 119 ′ and the first layer coil 121. An insulating layer 123 is formed for electrical insulation therebetween. As such, when the insulating layer 123 is formed, the top surface of the insulating layer 123 may maintain flatness. Here, the insulating layer 123 has through grooves 123a and 123b formed to allow the contact of the first layer coil 121 to be electrically connected to the second layer coil 131.

Thereafter, as shown in FIG. 3G, the second plating base layer 125 is formed on the insulating layer 123. The second plating base layer 125 is a layer for plating deposition of the second layer coil, and is formed by vacuum depositing a material having excellent electrical conductivity such as copper. Here, a portion of the material forming the second plating base layer 125 is filled in the through grooves 123a and 123b so that the contact between the first layer coil 121 and the second layer coil 131 is electrically connected. do.

Next, as shown in FIG. 3H, the second plating base layer 125 is patterned to correspond to the shape of the second layer coil 131 to be plated. That is, the second insulating groove 127 is formed by removing the second plating base layer 125 in a portion opposite to the second plating frame 129 of FIG. 3I.

Subsequently, as shown in FIG. 3I, a mold is applied to the patterned first plating base layer 125 ′ at a predetermined height, and then the mold is formed into a negative shape corresponding to the shape of the second layer coil 131. The plating mold is patterned to complete the second plating frame 129.

Thereafter, as illustrated in FIG. 3J, a metal is plated between the second plating frames 129 formed by patterning to form a second layer coil 131 having a helical structure having a predetermined line width to a predetermined thickness. Here, since the second layer coil 131 is used for flowing a large amount of current, it is preferable to form the second layer coil 131 by plating because it is a relatively thick metal film. As the plating method, both the electroplating method and the electroless plating method can be used.

Subsequently, as illustrated in FIG. 3K, the second plating mold 129 is heat treated. This is to completely remove the solvent remaining in the second plating mold 129, thereby minimizing thermal deformation of the heat-treated second plating mold 129 '. In this case, when the heat treatment step is performed, in consideration of the fact that the height of the second plating layer 129 ′ is lowered, as shown in FIG. 3J, the height of the second plating frame 129 is increased to the second layer coil ( By forming a relatively higher than the thickness of 131, the upper surface height of the second plating frame 129 'and the second layer coil 131 after the heat treatment step can be similar or the same as shown in Figure 3k. have. The heat treatment is possible through an oven, plate heating apparatus, ultraviolet curing apparatus, electron beam heat treatment apparatus and the like.

Subsequently, when a new coil layer is to be further laminated, an insulating layer is formed on the second layer coil 131 and the plating base layer forming step and the plating substrate layer patterning described with reference to FIGS. 3H to 3K are performed. By repeating the steps, the plating mold forming step and the coil forming step in order, a multilayer thin film multilayer microcoil may be manufactured.

As described above, the microcoil manufactured according to the thin film laminated microcoil manufacturing method according to the present invention is configured to maintain the flatness of the coil, even after the manufacturing process of the coil of one layer is completed, to manufacture the coil of the next layer. Even during the formation of the plating base layer, by maintaining the depth of focus of the optical system for exposure can maintain the resolution of the pattern, it is possible to fundamentally prevent the problem that the metal forming the second plating base layer is broken.

Therefore, the line widths of the coils of the other layers formed on the one layer coil and the spacing between the coils can be maintained within a desired range, thereby facilitating the production of multilayer thin film multilayer microcoils.

Claims (5)

Forming a plating base layer on the substrate; Patterning the plating base layer corresponding to the shape of the coil to be plated; Applying a mold to a predetermined height on the patterned plating base layer, and then patterning the mold to form a plating mold; Plating a metal between the plating molds to form a coil with a predetermined thickness; Forming an insulating layer on the plating mold and the coil; Including, the insulating layer is a thin film laminated microcoil manufacturing method characterized in that to maintain the flatness. The method of claim 1, further comprising heat-treating the plating die after the coil forming step, to remove the solvent remaining in the plating die and to make the plating die thermally stable. The method of claim 2, wherein after the heat treatment of the plating mold, the height of the plating mold is formed to be relatively higher than the thickness of the coil so that the heights of the upper surfaces of the coil and the plating mold are the same or similar. . The method according to any one of claims 1 to 3, The plating base layer forming step, the plating substrate layer patterning step, the plating mold forming step, and the coil forming step are repeated on the insulating layer at least one or more times in order, so that the flatness between each coil is maintained. Thin film laminated micro-coil manufacturing method characterized in that the coil is laminated in multiple layers. 5. The method of claim 4, wherein through holes are formed in the insulating layer so that the stacked coils are electrically connected, and a plating base layer formed on the insulating layer is configured to conduct electricity between the coils through the through holes. Thin film laminated microcoil manufacturing method.