JPH1161485A - Production of silicon steel sheet for printed board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the production of a metal-plated silicon steel sheet excellent in metallic coating adhesion by specifying the lightness index and roughness of the surface of a silicon steel sheet which is subjected to annealing and thereafter to oxide film removal treatment. SOLUTION: This production comprises: annealing a cold-rolled silicon steel sheet contg. 1.0 to 3.5 wt.% silicon; then, removing an oxide film on the surface of the annealed steel sheet, that is formed at the time of annealing the steel sheet, with a grinding means such as grinding roll, grinding brush or grinding stone; evaluating the lightness index and surface roughness of the surface of the resulting steel sheet after the oxide film removal treatment, based on the methods specified by JIS Z 8729 and JIS B 0601, respectively, to adjust the lightness index (L*) and surface roughness (Ra) to >=63 and 0.40 to 0.70 μm, respectively; and subjecting the surface of the steel sheet, thus obtained, to metal plating. As the metal plating, galvanizing is generally used, however, as plating other than the galvanizing, Sn-, Ni-, Cr-, Cu- or Al- plating can also be used, wherein, in any plating, the metallic coating thickness is preferably adjusted to 2.5 to 3.0 μm. The plating process is not particularly limited, however, an electroplating process, hot dip metal coating process, or the like is preferred.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to various OA equipment, V
The present invention relates to a method of manufacturing a metal-plated silicon steel sheet for a printed circuit board such as a TR, particularly to improve metal plating adhesion.

[0002]

2. Description of the Related Art Metal-plated silicon steel sheets are excellent in magnetic properties, heat dissipation, strength and the like, and are used as materials for motor circuits and stators of various OA equipment, VTRs and the like. Metals plated on silicon steel sheets are generally zinc, and metal-plated silicon steel sheets plated with metal such as zinc include:
An insulating layer such as an epoxy resin is formed on the metal plating layer, and a copper foil is adhered to form a printed circuit board.

Conventionally, in the production of this metal-plated silicon steel sheet, an oxide film on the surface of the silicon steel has been removed before plating in order to improve plating adhesion. Japanese Patent Application Laid-Open No. 63-35745 proposes a method for manufacturing a silicon steel sheet for a printed circuit board in which such an oxide film on the silicon steel surface is removed using a grinding roll in a strip state.
In Japanese Patent Application Laid-Open No. 2104618, a point analysis count value is measured by EPMA for Si, Al, and O on a silicon steel surface from which an oxide film has been removed, and when E = Si + Al / 10 + O is equal to or less than a predetermined value. A method for manufacturing a silicon steel sheet for a printed board to be subjected to metal plating is disclosed. Also, Japanese Patent Application Laid-Open No. 3-115595 discloses a method of manufacturing a silicon steel sheet for a printed circuit board on which metal oxide plating is performed when the oxide film removal state of a silicon steel strip is evaluated by a lightness index L ^* and the value is equal to or more than a predetermined value. A method is disclosed.

[0004]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open
In the technology described in JP-A-63-35745, the oxide film removal conditions were fixed at a fixed value, so that when the properties of the oxide film changed due to abnormalities in upstream processes such as finish annealing or changes in the conditions, the oxide film was removed. There was a problem that the removal could not be performed sufficiently and poor plating adhesion frequently occurred. Further, the technique described in Japanese Patent Application Laid-Open No. H2-104618 has a problem that point analysis by EPMA requires time and effort for sampling, cutting, adhesion, etc., and is unsuitable as an online evaluation means.

[0005] Further, in the technique disclosed in JP-A-3-115595, although evaluation of the oxide film removal state lightness index L ^*, lightness index L ^* is rated numerically different for the metal base color In addition to the problem of inconsistency, even if the value is not less than a predetermined L ^* value, poor plating adhesion may occur, and there is a problem that plating adhesion cannot always be stably improved.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and can easily and timely evaluate the state of removal of an oxide film in an oxide film removing step, apply metal plating, and stably provide excellent plating adhesion. An object of the present invention is to provide a method for manufacturing a metal-plated silicon steel sheet for a printed board, which can manufacture a metal-plated silicon steel sheet for a printed board.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, the state of removal of the oxide film has been determined by using the lightness index and the surface roughness as indices. It has been found that a metal-plated silicon steel sheet having excellent plating adhesion can be stably manufactured by evaluating the surface of the silicon steel sheet.

[0008] First, the experimental results on which the present invention is based will be described. With respect to the annealed silicon steel cold-rolled sheet containing Si: 1.85 wt%, an oxide film formed on the surface during annealing was removed by a grinding grinder. At this time, the degree of grinding was changed to change the oxide film removal state. After the oxide film removal treatment, the lightness index and the surface roughness of the steel sheet surface were measured. Lightness index is JIS Z 8729-1980
Compliant with the lightness index L ^*, the surface roughness was measured conforming to the surface roughness Ra in JISB 0601. After that, the surfaces of the ground cold-rolled steel sheets were plated with Zn, and the plating adhesion was evaluated. The plating adhesion was examined by visually judging plating peeling at 180 ° bending.は indicates no plating peeling, △ indicates partial peeling, and × indicates entire peeling. The plating adhesion is illustrated by the relationship between L ^* and Ra, and is shown in FIG. A region without plating peeling and a region with good plating adhesion are hatched regions where L ^* ≧ 63 and Ra = 0.40 to 0.70. That is, as an index for evaluating plating adhesion, it is effective to use a combination of a lightness index and surface roughness, and if L ^* and Ra are within a predetermined range, plating adhesion becomes stable and good. I got the knowledge.

The present invention has been made based on the above findings. According to the present invention, a hot rolled silicon steel sheet containing 1.0 to 3.5 wt% of Si is formed into a cold rolled sheet having a finished plate thickness by cold rolling, and then the cold rolled sheet is annealed, and then the oxidized sheet formed during the annealing is formed. In the method for manufacturing a silicon steel sheet for a printed circuit board, which performs an oxide film removing process for removing a film and performs metal plating, after performing the oxide film removing process, a state of removing the oxide film on the surface of the steel plate is defined by JIS Z 8729-1980. Lightness index L ^*
And a surface roughness Ra defined by JIS B 0601, and a method for producing a silicon steel sheet for a printed board, characterized in that the metal plating is performed when these values are within a predetermined range. Preferably, the lightness index L ^{* is} 63 or more, and the surface roughness Ra is 0.40 to 0.70 μm.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the reasons for limiting the components of a hot-rolled silicon steel sheet used for producing a metal-plated silicon steel sheet for a printed board according to the present invention will be described. Si: 1.0 to 3.5 wt% Si needs to contain 1.0 wt% or more for printed circuit boards in order to improve the electromagnetic characteristics. However, if it exceeds 3.5 wt%, the material becomes brittle, so that Si is 1.0 to 3.5 wt%. Limited to 3.5 wt%.

It is not necessary to specify alloying elements other than Si, but Al: 0.8 wt% or less, Mn: 0.35 wt% or less, C: 0.
005 wt% or less, P: 0.04 wt% or less, S: 0.003 wt% or less, Ti: 0.006 wt% or less. Next, the manufacturing method of the present invention will be described. The molten steel having the above composition is produced by a known method such as a converter or an electric furnace. After melting, ladle refining such as vacuum degassing may be performed. The molten steel is cast by a generally known means such as a continuous casting method and an ingot-making method to obtain a hot-rolled material.

The hot-rolled material is heated and hot-rolled by an ordinary method to form a hot-rolled sheet, and then cold-rolled to obtain a cold-rolled sheet having a final finished sheet thickness. The hot rolled sheet may be annealed before cold rolling if necessary. The cold rolled sheet having the finished sheet thickness is annealed. The annealing conditions for the cold rolled sheet are not particularly limited.
The treatment is preferably performed at 950 ° C. in a reducing atmosphere.

After annealing, the silicon steel sheet is subjected to an oxide film removing treatment for removing an oxide film formed on the surface during annealing. The removal of the oxide film is preferably performed over the entire length and width using a grinding roll, a grinding brush, a grinding grinder, or the like. In particular, the coil of annealed silicon steel sheet is unwound and passed through,
If the oxide film is removed by a grinding roll in the strip state, the oxide film can be removed efficiently and continuously continuously.

Next, the lightness index L ^* and the surface roughness Ra of the silicon steel sheet from which the oxide film has been removed are measured to evaluate the state of removal of the oxide film. Lightness index L ^* is JIS Z 8729-1980
It is measured in accordance with the regulations. L ^* is measured at three locations in the plate width direction as standard. The surface roughness Ra is JIS B
Measure in accordance with the provisions of 0601. As the surface roughness, a value measured at least in a direction (C direction) perpendicular to the steel sheet rolling direction is used. The standard measurement points are three places in the plate width direction.

The lightness index L ^* and the surface roughness Ra are measured by a laser colorimeter installed on the line exit side of the oxide film removing process.
And it can be easily measured by a surface roughness meter.
As a result, the state of removal of the oxide film on the surface of the silicon steel sheet can be grasped in a timely manner, and the operating conditions can be immediately changed based on the result. Only the silicon steel plate whose measured lightness index L ^* and surface roughness Ra are within predetermined ranges is then subjected to metal plating. The silicon steel sheet whose L ^* and Ra are out of the predetermined range is subjected to the oxide film removing treatment again.

The predetermined ranges of the lightness index L ^* value and the surface roughness Ra value are preferably set in advance according to the composition of the silicon steel sheet and the plating conditions such as the type of plating metal and the plating thickness. In the case of a silicon steel sheet for a printed circuit board, the predetermined range is a lightness index L ^* : 63 or more, and a surface roughness Ra: 0.40 to 0.70 mm.
It is preferred that If L ^* is less than 63, plating peeling may occur, and stable plating adhesion may not be obtained. Further, when the surface roughness Ra is less than 0.40, plating adhesion is reduced and plating peeling occurs. On the other hand, when Ra exceeds 0.70 mm, plating adhesion is improved, but the wear of grinding tools such as grinding rolls and grinding brushes becomes remarkable, which is not economical.

The metal plating applied to the silicon steel sheet is generally Zn, but may be Sn, Ni, Cr, Cu, or Al. The basis weight of the plating is preferably 2.5 to 3.0 μm. The method of metal plating is not particularly limited, but electroplating, hot-dip metal plating and the like are preferable.

[0018]

[Example] Si: 1.85 wt%, Al: 0.30 wt%, Mn: 0.20 wt
%, P: 0.040wt%, cold rolled on a hot rolled steel strip coil of silicon steel consisting of the balance Fe and unavoidable impurities, 0.50mm
After being formed into a thick cold-rolled steel strip, it was annealed at 900 ° C. (in a hydrogen atmosphere). Thereafter, the annealed cold-rolled steel strip was subjected to an oxide film removal treatment for continuously grinding with a grinding roll to remove an oxide film formed on the surface. The replacement of the grinding roll was performed on the way. After the oxide film removal processing step was completed, the lightness index L ^* and the surface roughness Ra were measured by a laser colorimeter and a surface roughness meter installed on the online exit side of the oxide film removal processing step. Ra was measured in the C direction. Thereafter, the annealed silicon steel cold-rolled steel strip was plated with 2.8 μm thick Zn. Take a test specimen from the metal-plated silicon steel strip and
The plating peeling state was investigated by bending, and the results are shown in Table 1. In the evaluation of plating adhesion, ○ indicates no peeling, Δ indicates partial peeling, and × indicates overall peeling.

[0019]

[Table 1]

Under these manufacturing conditions, predetermined ranges of the lightness index L ^* and the surface roughness Ra are L ^* ≧ 63 and Ra = 0.40 to 0.70 μm, and an application example within this range has excellent plating adhesion. On the other hand, in the comparative examples out of the range of the present invention, plating exfoliation occurred, and it can be seen that plating adhesion was reduced. As described above, according to the present invention, even if the oxide film removal conditions such as the change of the grinding roll are changed, the oxide film removal state of the silicon steel sheet surface is measured after the oxide film removal treatment, and it is determined that the silicon steel sheet is in the predetermined surface state. For confirmation, a metal-plated silicon steel sheet having good plating adhesion can be stably manufactured.

[0021]

According to the present invention, a metal-plated silicon steel sheet having excellent plating adhesion can be stably manufactured, and an industrially outstanding effect is achieved. In addition, the method for evaluating the state of removal of the oxide film is simple and can be measured online, and the state of removal of the oxide film can be evaluated in a timely manner and metal plating can be performed, which also has the effect of significantly improving productivity. .

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a lightness index L ^* and a surface roughness Ra which affect plating adhesion.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Eiji Hina 1-chome, Mizushima-Kawasaki-dori, Kurashiki-shi, Okayama Pref. 1-chome (without address) Inside Kawasaki Steel Corporation Mizushima Works

Claims (2)

[Claims] 1. A hot rolled silicon steel sheet containing 1.0 to 3.5 wt% of Si is formed into a cold rolled sheet having a finished plate thickness by cold rolling, and then the cold rolled sheet is annealed and formed at the time of the annealing. In the method for producing a silicon steel sheet for a printed circuit board, which performs an oxide film removing process for removing an oxide film and performs metal plating, after performing the oxide film removing process, the oxide film removal state of the steel sheet surface is determined according to JIS.
Lightness index L ^* specified by Z 8729-1980 and JIS B 0601
A method for producing a silicon steel sheet for a printed board, characterized in that the metal plating is performed when the surface roughness Ra is determined within a predetermined range. 2. The method for producing a silicon steel sheet for a printed circuit board according to claim 1, wherein the predetermined range is a lightness index L ^* : 63 or more, and a surface roughness Ra: 0.40 to 0.70 μm.