JP4662834B2 - Copper or copper alloy foil for circuit - Google Patents

Description

  The present invention relates to a copper or copper alloy foil for electric / electronic circuits. In particular, the present invention relates to a copper or copper alloy foil for electric / electronic circuits suitable for high-density mounting applications.

  In recent years, electronic devices are becoming lighter, thinner, and more multifunctional, and printed wiring boards mounted on electronic devices are required to be mounted with high density, for example, with multiple layers and fine pitches. In order to increase the number of layers, it is necessary to reduce the thickness of the conductor in order to reduce the thickness between the layers in terms of the conductor. On the other hand, in order to advance the fine pitch, it is necessary to develop a circuit pattern forming method for narrowing the conductor width and conductor spacing and to develop a conductor advantageous for circuit formation.

  As a typical method for forming a circuit pattern on the surface of a resin substrate, a subtractive method in which an etching resist is applied after bonding a resin substrate and a copper foil, and then a circuit pattern is formed by etching, and a resin After forming a seed layer such as a copper foil film on the base material, forming a plating resist and making a circuit pattern by copper plating, semi-additive method to remove the plating resist and seed layer, plating after catalyzing the resin base material There is an additive method in which a pattern is formed with a resist and a circuit pattern is formed with electroless copper plating.

  The semi-additive method and the additive method are suitable for fine pitch formation, but these methods have a problem that adhesion to the resin is lower than that of the subtractive method. In addition, the degree of freedom in selecting the copper foil is narrowed and the manufacturing cost is increased. On the other hand, since it is necessary to reduce the thickness of the copper foil in order to make the wiring fine pitch by the subtractive method, after bonding the copper foil and the resin from the viewpoint of handleability and manufacturability to make a copper clad laminate, A technique called half etching (also referred to as “thinning etching”) in which the copper foil is thinned by etching is used. For example, for a copper clad laminate having a thickness of 9 μm, a copper clad laminate using a copper foil having a thickness of 18 μm or 12 μm is first manufactured, and then the thickness of the copper foil is etched by etching using an oxidizing acid. Is often manufactured by a method of reducing the thickness to 9 μm.

  However, the copper foil that has been used conventionally has a problem that the unevenness of the half-etched surface becomes large, and bubbles are easily mixed during formation of the resist pattern. In addition, in electronic devices such as personal computers and mobile communications, electrical signals have become higher in frequency. However, when the frequency of electrical signals exceeds 1 GHz, the effect of the skin effect in which current flows only on the surface of the conductor becomes significant. The influence that the current transmission path changes due to the unevenness and the impedance increases cannot be ignored. From this point, it is desirable that the unevenness of the surface of the half-etched surface is small.

On the other hand, Japanese Patent Application Laid-Open No. 2003-193221 (Patent Document 1) discloses a technique for smoothening the surface after half-etching by increasing the crystal orientation toward the (200) plane. Specifically, the diffraction intensity (I) of the (200) plane obtained by X-ray diffraction of the rolled surface of a rolled copper foil having a thickness of 20 μm or less is the same condition as that for the rolled copper foil. Recrystallization temper rolling excellent in uniform etching thinning, characterized in that I / I ₀ > 50 with respect to diffraction intensity (I ₀ ) of (200) plane obtained by X-ray diffraction below A copper foil is disclosed.
Further, in Patent Document 1, even if the (100) plane (equivalent to the (200) plane) is oriented on the rolling surface, the crystal may rotate around the rolling surface ray, and such rotation It has been pointed out that when this occurs, the disorder of the atomic arrangement at the crystal grain boundary becomes large, and the grain boundary is selectively etched with respect to the inside of the grain to form a grain boundary groove.
Therefore, in Patent Document 1, in order to suppress this rotation, an angle formed by the [100] direction of the crystal and the rolling direction is defined. Specifically, the ratio of the number of crystals having an angle between the [100] direction and the rolling direction within 10 ° (θ ≦ 10 °) with respect to the total number of crystals is set to 60% or more (α ≧ 60%). It is described that the step of the crystal grain boundary becomes small and the step of the crystal grain boundary is hardly recognized by setting it to 80% or more (α ≧ 80%).
In addition, when copper is cold-rolled, it is described that small indentations are uniformly dispersed with high frequency in order to obtain a smooth etching surface by using a crack-like indentation generated on the surface as a starting point of corrosion. ing.

Japanese Patent Laid-Open No. 2003-19311

Although the surface shape of the half-etched surface could be improved by the technique described in Patent Document 1, the surface shape was not satisfactory enough for fine pitch applications. If a technology capable of obtaining a smoother half-etched surface is developed, it will contribute to high-density mounting of printed wiring boards.
Then, one subject of this invention is providing the copper or copper alloy foil from which a smooth surface is obtained when half-etching is performed.
Another object of the present invention is to provide a copper clad laminate using the copper or copper alloy foil.
Still another object of the present invention is to provide a printed wiring board using the copper clad laminate.
Still another object of the present invention is to provide a printed circuit board using the printed wiring board.

The inventor earnestly researched the cause of failure to obtain a satisfactory surface shape with the technique described in Patent Document 1, and obtained the following knowledge.
(1) Since a metal consists of many crystal grains from a rolled copper foil or an electrolytic copper foil to a copper foil produced by sputtering, and the etching rate varies depending on the crystal orientation of the metal, the crystal orientation differs. There is a step in the organizational unit.
(2) If the diameter of the crystal grains is large, even if the orientation difference is not so large, it causes a significant step after half etching. On the other hand, when the crystal grain diameter is small, even when the crystal orientation is different from that of the surroundings, the step generated after half etching can be reduced.
(3) If there are large precipitates (phases different from the base material) and impurities (contaminating foreign matter), these have different etching rates with the base material, so these portions remain undissolved and become convex portions, Conversely, it melts first and becomes a recess.
(4) The smoother the copper foil surface before half etching, the smoother the surface after half etching. And it is desirable to evaluate the smoothness degree of the copper foil surface using a predetermined parameter.

  Therefore, for (1), it is effective to orient the crystal grains constituting the copper foil in a specific orientation. For (2), it is effective to reduce the crystal grain size. For (3), it is effective to prevent the formation of large precipitates and the mixing of impurities. For (4), it is effective to smooth the copper foil surface before half-etching and to evaluate the smoothness with predetermined parameters.

The present invention completed on the basis of the knowledge as described above, in one aspect, when the plane formed from the plate thickness direction and the plate width direction (see FIG. 1) is observed, the [100] direction of the crystal and the rolling direction The copper or copper alloy foil for a circuit having a crystal grain area ratio of 80% or more and a maximum crystal grain size of 5 μm or less.

Furthermore, in another aspect of the present invention, when the plane formed from the plate thickness direction and the plate width direction is observed, the size of the inclusion is 1 μm or less, and the size (μm) the product of the number the number of the arithmetic mean and 1000μm inclusions per ² is copper or a copper alloy foil for circuit is under 1 nonzero.

  In addition, in another aspect of the present invention, when the projected area of the foil surface is Sm and the surface area is Sa, the circuit copper or copper alloy foil is Sa / Sm-1 ≦ 0.005 before half etching. is there.

  In addition, in another aspect of the present invention, when the projected area of the foil surface is Sm and the surface area is Sa, the circuit copper or copper alloy foil is Sa / Sm-1 ≦ 0.01 after half etching. .

  Moreover, this invention is the copper or copper alloy foil for rolling finishing in another one side surface.

  Moreover, this invention is copper or copper alloy foil for circuits refined by the recrystallized structure in another one side.

  Moreover, this invention is another one side. WHEREIN: It is the copper clad laminated board which used the copper or copper alloy foil which concerns on this invention as a material.

  Furthermore, this invention is another one side. WHEREIN: It is the printed wiring board manufactured through the process of using the said copper clad laminated board as a material and performing a half etching.

  Furthermore, in another aspect, the present invention is a printed circuit board in which electronic components are mounted on the printed wiring board.

  The copper or copper alloy foil according to the present invention has a smooth surface when half-etched.

<Types of copper foil>
The copper or copper alloy foil targeted by the present invention is a rolled copper foil. Generally, a rolled copper foil is manufactured by repeating plastic working and heat treatment with a rolling roll.
In addition to high-purity copper, such as tough pitch copper and oxygen-free copper, which are usually used as conductor patterns for printed wiring boards, copper foil materials such as copper containing Sn, copper containing Ag, copper added with Cr, Zr or Mg, etc. A copper alloy such as an alloy, a Corson copper alloy to which Ni, Si and the like are added can also be used. In addition, when the term “copper foil” is used alone in this specification, a copper alloy foil is also included.

  However, it should be noted that additive elements added to copper for the purpose of improving characteristics (eg, strength) also affect the characteristics required in the present invention. For this reason, Sn-containing copper is preferably used in the present invention because of the ease with which desired characteristics can be formed.

In the present invention, when copper or a copper alloy is used as a rolled copper foil, these may be in a hard state after rolling, or in a soft state in which this is further annealed and tempered into a recrystallized structure. Also good. Of course, other states may be used. However, since the flexibility increases when the copper or copper alloy foil is in a soft state, the soft copper or copper alloy foil is particularly suitable when used for a flexible printed wiring board (FPC).
The recrystallization structure is not limited, but from the viewpoint of FPC manufacturability, it is hardened by rough plating and cutting and then annealed or combined with heating when bonded to a resin substrate. It is normal to do.

  Specific examples of tempering into a recrystallized structure upon bonding to a resin substrate include, for example, a three-layer FPC using an adhesive made of a thermosetting resin such as epoxy, and a resin film such as copper foil and polyimide. Paste together. In order to cure the adhesive, heat treatment is performed at a temperature of 130 to 170 ° C. for several hours to several tens of hours. By this heat treatment, the copper foil can be tempered to a recrystallized structure. Moreover, in the casting method which is one of the manufacturing methods of the two-layer FPC, a varnish containing polyamic acid which is a precursor of a polyimide resin is applied on a copper foil and cured by heating to form a polyimide film on the copper foil. To do. In this heat curing treatment, heating is performed at a temperature of about 300 ° C. for several tens of minutes to several hours, and the copper foil can be tempered to a recrystallized structure by this heat treatment.

  In addition, the characteristics of the copper foil may change during the annealing process or the thermocompression bonding process with the resin, but if the copper foil satisfies the characteristics defined by the present invention before these heat treatments, the copper foil The foil can easily satisfy the characteristics defined by the present invention even after these heat treatments. However, since there is a risk of adversely affecting the characteristics depending on the heat treatment, for example, it is necessary to take care that the crystal grains and precipitates grow too much and the crystal grain diameter and precipitates do not exceed the specified range. Therefore, it is preferable to appropriately control the growth of crystal grains and precipitates by adjusting the heating temperature and heating time according to the composition of the copper or copper alloy used (in consideration of the recrystallization temperature). In general, as the heating temperature is higher and the heating time is longer, crystal grains and precipitates grow. At this time, additive elements such as Sn and Mg also have an effect of suppressing the growth of crystal grains.

<Crystal orientation>
As the crystal orientation of the copper foil is aligned, the etching rate difference at each location becomes smaller, and the half-etched copper foil surface becomes smooth. However, if the angle formed between the [100] direction of the crystal and the rolling direction in the plane formed from the plate thickness direction and the plate width direction is within 15 degrees, there is no significant difference in the etching rate. In order to provide a uniform etching rate, the area ratio of the crystal grains whose angle between the 100] direction and the rolling direction is within 15 degrees is 80% or more, preferably 90% or more, more preferably 95% or more. It is valid. Further, it is advantageous that the area ratio of the crystal grains in which the angle formed by the [100] direction of the crystal and the rolling direction is within 10 degrees is 80% or more, preferably 90% or more, more preferably 95% or more. is there. Further, it is advantageous that the area ratio of the crystal grains in which the angle between the [100] direction of the crystal and the rolling direction is within 5 degrees is 80% or more, preferably 90% or more, more preferably 95% or more. is there.

The area ratio of crystals having an angle between the [100] direction and the rolling direction of 15 degrees or less can be measured using an EBSP (Electron Backscattering Pattern) method. In the EBSP method, an electron beam is incident on a plane formed from the plate thickness direction and the plate width direction, and a Kikuchi pattern is obtained from the reflected electrons generated at this time. By analyzing this Kikuchi pattern, the crystal orientation of the electron beam incident position can be known. The orientation distribution of the sample surface is measured by scanning the sample surface in two dimensions with the electron beam and measuring the crystal orientation at every predetermined pitch (Naoya Ishibashi: Materials Science, Vol. 37, No. 3 (2000). Pp. 116-122).

  As a method for aligning the crystal orientation, any method known to those skilled in the art can be used. For example, in the case of a rolled copper foil, the degree of processing at the time of final cold rolling is increased (for example, 90% or more, further 99% or more). Examples thereof include a method of recrystallization annealing, a method of adding an element for suppressing the growth of crystal grains, and a method of controlling the crystal grain size after final annealing to be small.

<Grain size>
The regulation of the crystal orientation described above is to smooth the copper foil surface by reducing the etching rate difference by aligning the crystal orientation, but industrially, all the crystals are aligned in the same orientation. Have difficulty. Therefore, for example, if there is a crystal grain having another crystal orientation in the copper foil oriented in the 111 plane, the portion becomes a convex portion or a concave portion after half etching.
However, when the diameters are small, the amount of unevenness caused by the difference in etching rate is reduced, so that the smoothness of the copper foil surface is maintained. Therefore, in order to perform uniform etching in the plate thickness direction, the crystal grain size within an angle of 15 degrees between the [100] direction of the crystal and the rolling direction is 5 μm or less, preferably 3 μm or less, more preferably Is effectively 1 μm or less. Furthermore, it is effective that the grain size of the crystal grains whose angle between the [100] direction of the crystal and the rolling direction is within 10 degrees is substantially 5 μm or less, preferably 3 μm or less, more preferably 1 μm or less. . Further, it is effective that the grain size of a crystal grain having an angle of 5 degrees or less between the [100] direction of the crystal and the rolling direction is 5 μm or less, preferably 3 μm or less, more preferably 1 μm or less. However, if the crystal is too small, the material becomes hard and flexibility is impaired, so 0.01 μm or more is preferable.

Furthermore, even if the angle between the [100] direction of the crystal and the rolling direction is 15 degrees or less, a smaller diameter is advantageous for improving the uniform etching property. Therefore, in one embodiment of the present invention, when a plane formed from the plate thickness direction and the plate width direction is observed, regardless of the angle formed by the [100] direction of the crystal and the rolling direction, The maximum crystal grain size is 5 μm or less, preferably 3 μm or less, and more preferably 1 μm or less. However, if the crystal is too small, the material becomes hard and flexibility is impaired, so 0.01 μm or more is preferable.

  As a method for aligning the crystal orientation, any method known to those skilled in the art can be used. For example, in the case of a rolled copper foil, the degree of processing during the final cold rolling is increased (for example, 90% or more, and further 99% or more). Examples thereof include a method of recrystallization annealing, a method of adding an element for suppressing the growth of crystal grains, and a method of controlling the crystal grain size after final annealing to be small.

In this specification, the “crystal grain size” refers to the diameter of each crystal in the plate thickness direction when a plane formed from the plate thickness direction and the plate width direction of the copper or copper alloy foil is observed.

<Size of precipitates and impurities>
When precipitates or impurities having a composition different from that of the base material are present in the copper foil, a larger etching rate difference is likely to occur than crystal grains having different crystal orientations. Precipitates are intentionally added to improve the properties (for example, strength) of the copper foil, and impurities are inevitably mixed in the copper foil, so it is difficult to prevent them from being present at all. If it is 1 μm or less, it hardly becomes an obstacle when performing uniform etching in the thickness direction. However, it is desirable to provide a still significantly negative effect on unevenness of the number is greater if the surface below 1 [mu] m, the product precipitates and size arithmetic and 1000 .mu.m ² number per the impurities is below 1 nonzero, 5 and more desirably more than a bottom.

  In the present specification, the “precipitate” mainly refers to a precipitate of various elements known by those skilled in the art that are intentionally added to improve the properties (for example, strength) of the copper foil, such as Ni, Si, These are precipitates such as Cr, Zr, Be, Fe, Ti, Co, Mg, Ag, and P. Further, in this specification, “impurities” mainly refer to trace elements inevitably mixed in the manufacturing process of copper foil, furnace materials, refractories that are caught in molten metal when melting, foreign matters that are pushed into the material surface during rolling, and the like. . However, in the present invention, the distinction between “precipitates” and “impurities” and their strict definitions are not a problem, and it is sufficient to understand them as inclusions as they generally indicate phases different from the copper matrix.

In this specification, “size of precipitates and impurities” means the thickness direction of individual precipitates and impurities when a plane formed from the plate thickness direction and the plate width direction of copper or copper alloy foil is observed. Refers to the diameter.

  As a method for controlling the size of the precipitate, any method known to those skilled in the art can be used.For example, the timing of adding the additive element during melting casting, the temperature and time during solution treatment, and the like. It can be controlled by appropriately adjusting the adjustment, the temperature and time of the aging treatment, the degree of processing during cold working, and the like.

<Smoothness of copper foil surface before half etching>
Since the characteristics of the copper or copper alloy foil according to the present invention described so far are mainly for reducing the etching rate difference, the influence of the surface shape before half etching is inevitable. If the surface shape before half etching is poor, the surface shape after half etching also deteriorates, so the copper foil surface before etching is required to be smooth. When evaluating the smoothness, it is more advantageous to use the following parameters to evaluate the smoothness of the surface. That is, in the present invention, when the projected area of the copper foil surface before half etching is Sm and the surface area is Sa, it is desirable to satisfy Sa / Sm-1 ≦ 0.005, and Sa / Sm-1 ≦ 0.004. More desirable.

  The smoothness of the copper foil surface before half-etching can be controlled using any method known to those skilled in the art. For example, in rolled copper foil, the degree of processing for each pass during rolling, sheet feeding speed, rolling oil It can be adjusted by appropriately changing the type, the viscosity of the rolling oil, the diameter of the rolling roll, the roughness of the rolling roll surface, the rolling reduction (the thickness of the sheet to be crushed by one rolling), and the like.

  In addition, since half etching is usually performed only on the outer surface of the copper foil after the copper clad laminate is formed, that is, the surface opposite to the side bonded to the substrate, the copper or copper according to the present invention is used. The foil surface of copper alloy foil should just have the said smoothness at least one side.

  According to one embodiment of the present invention, the copper foil surface obtained after half-etching satisfies Sa / Sm-1 ≦ 0.01, preferably Sa / Sm-1 ≦ 0.008, more preferably Sa /. Sm-1 ≦ 0.007 is satisfied.

<Thickness>
Although the thickness of the copper or copper alloy foil according to the present invention is not particularly limited, it is intended to reduce the thickness of the copper foil by half-etching mainly for the purpose of making the circuit fine pitch, or half-etching In view of the fact that if the thickness is too thick, a long etching time is required and productivity is lowered, the thickness before half etching is usually 50 μm or less, for example, 10 μm to 30 μm, and typically 12 μm or 18 μm. Degree. Further, when the thickness of the copper foil is reduced, the strain generated on the outer periphery of the bent portion at the time of bending is reduced and the flexibility is improved. Therefore, the thickness of the above level is preferable in consideration of application to FPC.
Etching for circuit formation is usually performed after half-etching, but if the thickness of the copper foil after half-etching exceeds 20 μm, the etching factor is significantly reduced and adversely affects fine pitching. The thickness of the copper foil surface after half etching is 20 μm or less, preferably 10 μm or less.

  Using the copper or copper alloy foil according to the present invention, a copper-clad laminate and further a printed wiring board can be produced according to a conventional method. Since the copper or copper alloy foil according to the present invention is characterized in that a smooth surface is obtained when half-etching is performed, half-etching is performed in the process of manufacturing a printed wiring board from the copper-clad laminate. It can be particularly preferably used when a process is included. By performing half etching using the copper or copper alloy foil according to the present invention, an extremely thin (for example, 10 μm or less) smooth etching surface can be obtained, so that the resist pattern accuracy is improved and the printed wiring board is densely mounted. This can contribute to increasing the frequency (for example, increasing the number of layers and fine pitch) and increasing the frequency. Although it is not limited, it is typically expected to be used when forming a circuit pattern having a thickness of about 5 to 10 μm and a width of about 15 to 50 μm.

  In this specification, “half etching” refers to etching performed to reduce the thickness of copper or copper alloy foil, used interchangeably with thinning etching, and limited to halving the thickness. Is not to be done. Any method known to those skilled in the art can be used as the half-etching method. For example, a soft etching solution (ammonium persulfate, sodium persulfate, sulfuric acid + hydrogen peroxide, etc.) is used by immersion or spraying. Can do.

  Various printed wiring boards (PWB) can be manufactured using the copper or copper alloy foil according to the present invention, and are not limited. For example, from the viewpoint of the number of layers of the conductor pattern, single-sided PWB, double-sided PWB and multilayer PWB (three or more layers) can be manufactured, and rigid PWB, flexible PWB (FPC), and rigid flex PWB can be manufactured from the viewpoint of the type of insulating substrate material. Note that since the thickness of the foil can be reduced, an FPC capable of high-density mounting on an electronic device is preferable. A printed circuit board can be manufactured by mounting various electronic components on these PWBs by soldering or the like.

  EXAMPLES Next, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to these.

<Invention Examples 1-5, Comparative Examples 1-4>
Sn was added to oxygen-free copper (ASTM H 170 Grade 2) so as to be 0.10 to 0.20 mass% depending on the sample, and a 200 mm thick copper ingot was melted by a vacuum induction heating furnace. This ingot was hot-rolled from 900 ° C. to obtain a plate having a thickness of 10 mm. Thereafter, cold rolling and annealing were repeated, and finally, a copper foil having a thickness of 18 μm was processed by cold rolling. In the final cold rolling, the degree of work and the roughness of the rolling roll used were variously changed.

The rolling degree (R) is defined by the following formula.
R = (t ₀ −t) / t ₀ × 100 (t ₀ : thickness before rolling, t: thickness after rolling)
The following evaluation was performed about the copper foil produced as mentioned above.

The surface roughness of the rolling roll was defined by the arithmetic average roughness Ra.
According to JIS B0601, the surface roughness (Ra) was calculated | required using Mitutoyo Corporation model SJ-301. The reference length was set to 0.25 mm and measured in the roll width direction. Ra was measured three times at different locations, and the average value was obtained.

(1) Area ratio: After embedding a crystal grain-copper foil in a resin and polishing it, the cross section was electropolished in phosphoric acid to prepare a measurement sample. Thereafter, using an OIM (Orientation Imaging Micrograph) manufactured by TSL, an area of 100 μm × 10 μm shown in FIG. 2 was measured for 3 fields at intervals of 0.5 μm, and the angle formed by the [100] direction and the rolling direction was 15 The area ratio within the range was analyzed by OIM manufactured by TSL.
(2) Crystal grain size: After embedding a copper foil in a resin and polishing it, the cross section was electrolytically polished in phosphoric acid to prepare a measurement sample. Then, using an OIM (Orientation Imaging Micrograph) manufactured by TSL, the area of 100 μm × 10 μm shown in FIG. 2 was measured for 3 fields at intervals of 0.5 μm, and the largest crystal grain size in the measured surface was measured. It was measured.
(3) Size and number of inclusions : After embedding a copper foil in a resin and polishing it, the cross section was electropolished in phosphoric acid to prepare a measurement sample. After that, the FESEM (Field Emission Scanning Microscope) model XL30SFEG manufactured by Philips was observed at any three locations of the 100 μm × 10 μm area shown in FIG. 2, and the arithmetic mean and number of inclusions were measured. did.
(4) Smoothness of the surface of the copper foil: using an electron beam three-dimensional roughness measuring device manufactured by ELIONIX, model ERA-8000, the projected area near the center of the sample surface Sm = 4.3 × 10 ⁴ μm ² The surface area Sa was measured to determine the surface smoothness Sa / Sm-1.
(5) Half-etching: Half-etching was performed until the plate thickness was reduced to half (9 μm) by dipping a copper foil with only one side exposed with a soft etching solution of sulfuric acid 100 g / L and hydrogen peroxide 30 g / L.

  Table 1 shows the measurement results of the prepared samples. No. 1, 2 and 4 are the surface smoothness Sa / Sm-1 before half etching is 0.005 or less, but the crystal grain area ratio is within 15 degrees between the [100] direction of the crystal and the rolling direction. Is 80% or less, and the half-etched surface was not sufficiently smooth. On the other hand, no. 3, 5, 6, and 7 are surface smoothness before half etching, Sa / Sm-1 is 0.005 or less, and the area ratio of crystal grains having an angle of 15 degrees or less is 80% or more, and the half etching surface is sufficient. Smoothness was obtained. No. No. 8 had an area ratio of 80% or more. However, since the surface smoothness Sa / Sm-1 before half etching exceeded 0.005, the half etching surface could not obtain sufficient smoothness. This is considered to reflect the influence of the degree of work in the final cold rolling, the added Sn, and the roughness of the rolling roll.

  Subsequently, no. The sample No. 7 was subjected to a heat treatment (350 ° C. for 10 minutes in an Ar atmosphere) assuming that it was bonded to the resin. Nine samples were prepared. Table 2 shows the evaluation results of the characteristics. Even when heat treatment was performed, the area ratio of the crystal grains within 15 degrees did not change, and the half-etched surface was sufficiently smooth.

<Invention Example 6, Comparative Example 5>
Next, each element is added to electrolytic copper (JIS H2121-61) so as to be 3.0% by mass Ni, 0.65% by mass Si, and 0.15% by mass Mg. Thus, a copper ingot having a thickness of 200 mm was melted. Then, what was annealed at 800 ° C. for 1 hour and that annealed at 900 ° C. for 1 hour were each rolled to 10 mm by hot rolling, then subjected to aging treatment at 500 ° C. for 3 hours, and surface oxidation by face milling After removing the material, rolling and annealing were repeated, and the final cold rolling was processed into a copper foil having a thickness of 18 μm with a working degree of 99%. The copper foil produced as described above was evaluated in the same manner as described above.

  Table 3 shows the measurement results of the prepared samples. No. In No. 10, since the annealing temperature after casting was low, a coarse precipitate of Ni—Si was generated and remained undissolved during half etching, resulting in unevenness. On the other hand, no. Since No. 11 had a high annealing temperature after casting, the Ni—Si precipitate was small, and sufficient smoothness was obtained even after half-etching.

It is a schematic diagram which shows the plane formed from a board thickness direction and a board width direction . It is a figure which shows the observation surface of the test piece used in the Example.

Claims (7)

When the plane formed from the plate thickness direction and the plate width direction is observed, the area ratio of the crystal grains whose angle between the [100] direction of the crystal and the rolling direction is within 15 degrees is 80% or more, and the crystal particle size Ri der less than 5μm at most,
When the plane formed from the plate thickness direction and the plate width direction is observed, the size of the inclusion is 1 μm or less, and the arithmetic average of the size (μm) and the number of inclusions per 1000 μm ² The product is 10 or less,
When the projected area of the foil surface is Sm and the surface area is Sa, Sa / Sm-1 ≦ 0.005 before half etching.
Copper or copper alloy foil for circuits. When the projected area of the foil surface was Sm, the surface area Sa, circuit copper or copper alloy foil according to claim 1 after half etching is Sa / Sm-1 ≦ 0.01. Circuitry for copper or copper alloy foil according to claim 1 or 2 which is state of the rolling finish. Circuitry for copper or copper alloy foil according to any one of claim 1 to 3 which is a state like that tempered recrystallization structure. The copper clad laminated board which used the copper or copper alloy foil as described in any one of Claims 1-4 for the material. A printed wiring board manufactured by a half-etching process using the copper-clad laminate according to claim 5 as a material. A printed circuit board manufactured using the printed wiring board according to claim 6 .