JP2003242732A - Production method of load beam with insulation layer between plates of different thickness by means of simultaneous working - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method of a load beam with an insulation layer for a hard disk which enables high-precision and low-cost working so as to correspond to the higher precision of the hard disk. <P>SOLUTION: The production method is a method for producing the load beam for the hard disk by using a laminate of three layer constitution in which a metal layer 1 is laminated on the metal layer 3 exhibiting a spring characteristic via an electric insulation layer 2. Therein, the metal layer is efficiently subjected to etching working in a short time and, thereby, the production method of the load beam with the high-precision insulation layer is established. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method of manufacturing a load beam for a hard disk. In particular, the present invention relates to a method of manufacturing a load beam for a hard disk including an insulating layer between metal material layers having different plate thicknesses.

[0002]

2. Description of the Related Art A conventional load beam for a hard disk has been manufactured solely from a stainless steel material because it is required to mechanically support a magnetic head. However, at the present time when the areal recording density of hard disks has dramatically increased, it is required to reduce the suspension flying height, and the load beam is required to have damping characteristics. Therefore, there has been proposed a technique for improving damping characteristics by manufacturing a load beam, which has been conventionally used only with a stainless material, with a composite material of stainless material / insulating layer / stainless material. FIG. 2 is a diagram showing an example of a load beam including such an insulating layer. FIG. 3 shows a method of manufacturing the load beam having this configuration. When processing the metal layer of the composite material having different thicknesses including the insulating layer shown in claim 2, since the insulating layer is present,
Two types of metal layers are processed for each metal layer. That is, this is a manufacturing method that requires the metal layer to be processed twice.

[0003]

In order to cope with the present day when the areal recording density of hard disks has dramatically increased, it is required to manufacture a load beam with high accuracy. Therefore, the present invention is a method of manufacturing a load beam made of a composite material of a metal layer / insulating layer / metal layer, by researching processing techniques of both metal layers, and manufacturing a load beam with an insulating layer with high precision. .

[0004]

The present inventor has completed the invention described below as a result of studies to solve the above problems. That is, the present invention introduces a new concept of simultaneously etching both metal layers in order to efficiently manufacture a load beam with an insulating layer, and establishes a method for manufacturing a load beam with an insulating layer.

According to a first aspect of the present invention, in order to meet the demand for a high precision hard disk, the insulating layer of the hard disk load beam consisting of metal layer / insulating layer / metal layer can be processed with high precision. Is a manufacturing method. With this manufacturing method, a highly accurate load beam can be manufactured.

According to a second aspect of the present invention, in the method of manufacturing the load beam with an insulating layer for a hard disk according to the first and second aspects, a material in which the support portion of the metal material layer is thicker than the other metal material layer. A method of manufacturing a load beam for a hard disk, characterized by using. With this manufacturing method, the load beam with an insulating layer can be efficiently manufactured.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is a process chart showing a procedure for manufacturing a load beam for a hard disk, and the process will be described below step by step.

FIG. 3 (a) shows a laminated body for forming a load beam for a hard disk. In this laminated body, stainless steel which is the metal layer 1 is laminated by thermocompression bonding on the stainless steel which is the metal layer 3 which exhibits spring characteristics, with the insulating layer 2 interposed therebetween. The insulating layer 2 used here is a polyimide resin, an epoxy resin, or an acrylic resin. In the case of polyimide, the polyimide layer is composed of a core insulating layer and an adhesive layer laminated on both surfaces thereof. The adhesion strength between the metal layer 1 or 3 and the insulating layer 2 is at least 500 g / cm or more, and the adhesion strength between the metal layer 1 and the insulating layer 2 and the adhesion strength between the metal layer 3 and the insulating layer 2 are Uniform adhesion strength is required within an error of ± 20%.

FIG. 3B shows a state in which a liquid resist 4 such as casein which is a photosensitive material is applied on both surfaces of the metal layer 1 and the metal layer 3. A dry film resist may be used as the resist.

FIG. 3C shows a state in which the liquid resist 4 is patterned by irradiating the ultraviolet exposure 6 through a mask.

FIG. 3D shows a state in which the resist in the unexposed portion is dissolved after patterning through the mask 5.

FIG. 3E shows a state in which the metal layer 1 and the metal layer 3 are etched through the patterned resist 4. In this case, the metal layer 1 and the metal layer 3 are etched at the same time by using an etching solution composed of a general ferric chloride solution.

FIG. 3 (f) shows a state in which the resist 4 is stripped by a stripping solution made of sodium hydroxide after the metal layer 1 and the metal layer 3 are etched. As a result, as shown in the drawing, a three-layer laminate in which the metal layer 1 and the metal layer 3 are patterned on both surfaces of the insulating layer 2 is obtained.

As described above, the production of the metal layer of the load beam with an insulating layer for a hard disk is completed by the procedure shown in FIG.

[0016]

[Example] A polyimide film having a thickness of 12.5 μm was used as a core insulating layer, and a polyimide varnish was used as an adhesive layer so that the film thickness after drying was 2.0 ± 0.3 μm. Then, it was used as an insulating layer of a film with an adhesive. Then, this film with an adhesive layer was sandwiched between stainless steel having a thickness of 30 μm and stainless steel having a thickness of 64 μm and vacuum hot pressed to form a metal layer / insulating layer / metal layer laminate. Here, the adhesion strength between the stainless steel and the polyimide of the formed laminate was measured in accordance with the adhesion strength measurement method of IPC 2.4.9. The measurement result shows that the adhesion strength between 30 micron-stainless steel and polyimide is 1.8 kg / c.
m, 64 micron-The adhesion strength between stainless steel and polyimide was 1.6 Kg / cm. For the above laminate,
Acrylic dry film resists were laminated on both sides of 30-micron and 64-micron stainless steel, and then both dry film resists were exposed and developed according to predetermined photomask patterns, and patterned.
The exposure was carried out at an exposure dose of 40 to 70 mJ / cm ² , and the development was carried out by spray development at 30 ° C. and 1 wt% Na ₂ CO ₃ . Next, the stainless steel on both sides was simultaneously etched using a ferric chloride solution. As a result, a three-layer laminate in which stainless steel was patterned on both surfaces of the polyimide film was obtained.

[0019]

As described above, according to the present invention,
By etching different plate thicknesses at the same time, the etching time can be shortened and the manufacturing cost can be reduced. As a result, a low-cost manufacturing method of a load beam with an insulating layer for a hard disk, which enables highly accurate processing, has become possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a laminate used in the present invention.

FIG. 2 is a diagram of a finished product of the load beam with an insulating layer for a hard disk manufactured according to the present invention. (A) is a perspective view. 2B is a sectional view taken along the line AA ′ of FIG.

FIG. 3 is a process drawing showing an example of a manufacturing procedure of a load beam with an insulating layer for a hard disk.

[Explanation of symbols]

1 metal layer 2 insulating layers 3 metal layers 4 resist 5 glass mask 6 UV exposure

Claims (2)

[Claims] 1. A method of manufacturing a load beam for a hard disk by processing a suspension material in which three layers of materials, which exhibit spring characteristics, a metal material layer, an insulating layer, and a metal material layer are laminated in this order. A method for manufacturing a load beam with an insulating layer for a hard disk, which is characterized in that it can be processed with high precision. 2. A method of manufacturing a load beam for a hard disk, wherein the metal materials shown in FIGS. 1-1 and 3 having different thicknesses of the support portion of the metal material layer can be simultaneously etched.