JP7094151B2 - Oxygen-free copper plate and ceramic wiring board - Google Patents

Description

The present invention relates to an oxygen-free copper plate and a ceramic wiring board.

A ceramic wiring board may be used as a substrate on which a semiconductor element is mounted (see, for example, Patent Documents 1 and 2). The ceramic wiring board is formed by joining a ceramic substrate and an oxygen-free copper plate which is provided on one of the main surfaces of the ceramic substrate and whose predetermined portion is removed by etching to form a wiring pattern (copper wiring), for example. ing. As a method for joining the ceramic substrate and the oxygen-free copper plate, a direct bonding method in which a copper oxide layer formed on the bonding surface of the ceramic substrate with the ceramic substrate is melted to bond the two, and activity of titanium (Ti) or the like are used. An active metal brazing method or the like is used in which a brazing material to which a metal is added is used to join the two.

Japanese Unexamined Patent Publication No. 61-296788 Japanese Unexamined Patent Publication No. 9-36540

In the above-mentioned joining method, since a metal such as copper (Cu) or Ti is melted, heating in a high temperature range (for example, 800 to 1080 ° C.) is involved in the joining process. However, when the oxygen-free copper plate is heated at a high temperature, copper crystals (copper crystal grains) constituting the oxygen-free copper plate may grow and become coarse.

An object of the present invention is to provide an oxygen-free copper plate capable of suppressing the coarsening of crystals even when heated at a high temperature and related techniques thereof.

According to one aspect of the invention
By rolling, it is formed into a flat plate,
It has a crystal whose crystal planes parallel to the rolled plane are {022} plane, {002} plane, {113} plane, {111} plane and {133} plane.
The diffraction peak intensities of each of the crystal planes obtained by the X-ray diffraction measurement by the 2θ / θ method for the rolled surface are I _{022} , I _{002} , I _{113} , I _{111} , I _{133} , respectively. When
I _{022} / (I _{022} + I _{002} + I _{113} + I _{111} + I _{133} ) ≤ 0.3.
(I _{002} + I _{113} ) / (I _{111} + I _{133} ) ≧ 1.0, and
I _{002} / I _{022} ≧ 1.0,
I _{113} / I _{022} ≧ 0.5,
I _{111} / I _{022} ≧ 0.15,
I _{133} / I _{022} ≧ 0.02,
0.5 ≤ I _{002} / I _{113} ≤ 5.0.
0.2 ≤ I _{133} / I _{111} ≤ 0.5,
1.0 ≤ I _{113} / I _{111} ≤ 10
1.0 ≤ I _{002} / I _{111} ≤ 20
1.0 ≤ I _{002} / I _{133} ≤ 75,
1.0 ≤ I _{113} / I _{133} ≤ 30.
Provided are oxygen-free copper plates having an average crystal grain size of 0.4 mm or less after heat treatment for 10 minutes under the condition of 900 ° C. and related techniques thereof.

According to the present invention, even when the oxygen-free copper plate is heated at a high temperature for joining with a ceramic substrate or the like, it is possible to suppress the coarsening of crystals constituting the oxygen-free copper plate.

It is explanatory drawing of the position of the neutral point concerning the Example of this invention.

<Findings obtained by the inventor, etc.>
Prior to the description of the embodiment of the present invention, the findings obtained by the present inventor will be described.

The oxygen-free copper plate is produced by performing cold rolling, final cold rolling, or the like on the ingot. When cold rolling is performed, the copper crystals in the material to be rolled rotate toward the {022} plane, so that the material to be rolled contains crystals whose crystal plane parallel to the rolled surface is the {022} plane. Easy to develop. Therefore, in the oxygen-free copper plate after the final cold rolling, the number of crystals on the {022} plane increases, and the number of crystals on other crystal planes decreases.

When the oxygen-free copper plate is heated to a high temperature, the crystals in the oxygen-free copper plate are recrystallized to generate new crystals (recrystallized grains). The recrystallized grains have a specific orientation related to the crystal orientation of the crystal before recrystallization. For example, a crystal on the {022} plane in an oxygen-free copper plate is recrystallized by high-temperature heating to change into a crystal whose crystal plane parallel to the rolled plane is the {002} plane.

When the crystals in the oxygen-free copper plate are recrystallized, the crystals having the same crystal orientation are likely to coalesce and aggregate, and as a result, the crystals in the oxygen-free copper plate are likely to be coarsened. For example, when an oxygen-free copper plate having many {022} plane crystals as described above is heated at a high temperature, the {022} plane crystal changes to a {002} plane crystal by recrystallization, and these crystals are united and assembled. And it becomes coarse. As described above, the coarsening of the crystals in the oxygen-free copper plate by high-temperature heating largely depends on the crystal orientation of the crystals present in the oxygen-free copper plate after the final cold rolling.

Therefore, in order to suppress the development of crystals on the {022} plane in the final cold rolling, it is conceivable to keep the total workability of the final cold rolling low. However, if the total degree of processing of the final cold rolling is lowered, the strain energy accumulated inside the material to be rolled (the finally obtained oxygen-free copper plate) decreases, so that it is recrystallized during recrystallization by high-temperature heating. This leads to a decrease in the frequency of crystal nuclei. As a result, the number of crystals in the oxygen-free copper plate after high-temperature heating is reduced, that is, the crystals are coarsened.

Therefore, the present inventors have conducted diligent research on oxygen-free copper plates in order to suppress crystal coarsening due to high-temperature heating without lowering the total workability of the final cold rolling. As a result, the number of crystals on the {022} plane in the oxygen-free copper plate before high-temperature heating is reduced, and a certain amount of crystals (the crystal plane parallel to the rolled plane is a plane other than the {022} plane) are contained in the oxygen-free copper plate ( It was found that the above problem can be solved by making it exist (a certain number). The present invention is based on the above findings found by the inventor and the like.

<One Embodiment of the present invention>
Hereinafter, an embodiment of the present invention will be described.

(1) Configuration of oxygen-free copper plate First, the configuration of the oxygen-free copper plate will be described.

The oxygen-free copper plate according to the present embodiment is formed into a flat plate shape (plate shape) by being rolled in a predetermined direction by, for example, rolling. The rolled surface of the oxygen-free copper plate is the main surface (main surface). The thickness of the oxygen-free copper plate is, for example, 100 μm or more.

The rolled oxygen-free copper plate is composed of a plurality of crystals, that is, polycrystals. The oxygen-free copper plate has crystals in which the crystal planes parallel to the rolled plane are {022} plane, {002} plane, {113} plane, {111} plane, and {133} plane. Since a plurality of crystals are exposed on the rolled surface of the oxygen-free copper plate and the oxygen-free copper plate is polycrystal as described above, the rolled surface is not composed of only one crystal plane.

In the present specification, a crystal whose crystal plane parallel to the rolled plane is a {022} plane is also referred to as a {022} plane crystal. The same applies to crystals whose crystal planes parallel to the rolled plane are {002} plane, {113} plane, {111} plane, and {133} plane. Crystals whose crystal planes parallel to the rolled plane are {002} plane, {113} plane, {111} plane, and {133} plane are collectively referred to as "crystals of each crystal plane in the sub-direction". The main orientation plane of the copper crystal in the rolled oxygen-free copper plate is the {022} plane.

As described above, when the oxygen-free copper plate is heated to a high temperature, when the crystals on the {022} plane in the oxygen-free copper plate change to the crystals on the {002} plane due to recrystallization, the crystals coalesce and aggregate. The crystals in the oxygen-free copper plate are coarsened. For this reason, in order to prevent the crystals in the oxygen-free copper plate from becoming coarse due to high-temperature heating (hereinafter, also referred to as “crystal coarsening due to high-temperature heating”), the {022} surface existing in the oxygen-free copper plate is present. It is necessary to reduce the number of crystals. For example, it is necessary to sufficiently reduce the diffraction peak intensity of the {022} surface obtained by the X-ray diffraction measurement by the 2θ / θ method for the rolled surface of the oxygen-free copper plate.

Even when the oxygen-free copper plate is heated at a high temperature, the crystal of each crystal plane in the sub-direction hardly changes to a crystal whose plane parallel to the rolled plane is another crystal plane. Therefore, in order to suppress crystal coarsening due to high-temperature heating, it is necessary to have a certain amount of crystals on each crystal plane in the sub-direction present in the oxygen-free copper plate. For example, it is necessary to set the diffraction peak intensities of the crystal planes in the sub-directions obtained by the X-ray diffraction measurement by the 2θ / θ method for the rolled surface within a predetermined range.

As described above, a close relationship is observed between the crystal coarsening due to high temperature heating and the crystals on the {022} plane and the crystals on each crystal plane in the sub-direction in the oxygen-free copper plate. In order to suppress crystal coarsening due to high temperature heating, it is necessary to adjust the balance of the above-mentioned diffraction peak intensities of the {022} plane and each crystal plane in the sub-direction.

The oxygen-free copper plate has the diffraction peak intensities of the {022} plane, {002} plane, {113} plane, {111} plane and {133} plane obtained by X-ray diffraction measurement by the 2θ / θ method for the rolled surface, respectively. When I {022}, I {002}, I _{113} , I _{111} , and I _{133} , all of the following equations (1) to (12) are satisfied.

Equation (1): I _{022} / (I _{022} + I _{002} + I _{113} + I _{111} + I _{133} ) ≦ 0.3
Equation (2): (I _{002} + I _{113} ) / (I _{111} + I _{133} ) ≧ 1.0
Equation (3): I _{002} / I _{022} ≧ 1.0
Equation (4): I _{113} / I _{022} ≧ 0.5
Equation (5): I _{111} / I _{022} ≧ 0.15
Equation (6): I _{133} / I _{022} ≧ 0.02
Equation (7): 0.5 ≤ I _{002} / I _{113} ≤ 5.0
Equation (8): 0.2 ≤ I _{133} / I _{111} ≤ 0.5
Equation (9): 1.0 ≤ I _{113} / I _{111} ≤ 10
Equation (10): 1.0 ≤ I _{002} / I _{111} ≤ 20
Equation (11): 1.0 ≤ I _{002} / I _{133} ≤ 75
Equation (12): 1.0 ≤ I _{113} / I _{133} ≤ 30

The above equation (1) shows that the diffraction peak intensity of the {022} plane is sufficiently low, which is 30% or less of the diffraction peak intensity of each crystal plane in the sub-direction (crystal plane other than the {022} plane). .. This means that the number of crystals on the {022} plane in the oxygen-free copper plate is sufficiently small.

In the above equation (2), the ratio of the total (I _{002} + I _{113} ) of the diffraction peak intensity of the {002} plane and the diffraction peak intensity of the {113} plane is the diffraction peak intensity of the {111} plane. It shows that it is higher than the ratio of the total (I _{111} + I _{133} ) with the diffraction peak intensity of the {133} plane. This indicates that the compressive component applied to the material to be rolled in the final cold rolling described later is higher than the tensile component, that is, the compressive stress is dominant over the tensile stress in the final cold rolling.

The above formulas (3) to (6) show the ratio of the copper crystals that have not rotated to the {022} plane to the copper crystals that have rotated (changed) to the {022} plane by the final cold rolling described later. There is.

In the above equations (7) and (8), when the copper crystal is rotated to the {022} plane by the final cold rolling described later, the diffraction peak intensities between the crystal planes observed in the paths 1 and 2 described later are obtained. The ratios are shown respectively.

In the above equations (9) to (12), when the copper crystal is rotated to the {022} plane by the final cold rolling described later, the diffraction peak between the crystal planes observed in the paths other than the paths 1 and 2 described later. The ratio of strength is shown respectively.

By considering the equations (9) to (12) and the equations (7) and (8) together, the diffraction peak intensity between the crystal planes that did not rotate to the {022} plane by the final cold rolling described later. It shows all the ratios of.

It should be noted that the relationship between the diffraction peak intensities of each crystal plane shown in the above equations (1) to (12) changes in conjunction with the range of other equations if the range of one or more equations changes. Is. For example, in order to increase the range of the lower limit of the formula (3), the value of I _{002} may be increased, but in this case, the numerator of the formula (7) also becomes large, and the value of the formula (7) is the upper limit. It may exceed the value of 5.0. Such a relationship applies to all of the above equations (1) to (12).

As a raw material (base material) for the oxygen-free copper plate, it is preferable to use oxygen-free copper (Oxygen Free Copper: OFC) having excellent thermal conductivity and hydrogen brittleness resistance. As the oxygen-free copper, it is preferable to use oxygen-free copper having a purity of 99.96% or more specified in JIS C1020, H3100, etc. from the viewpoint of suppressing a decrease in conductivity (conductivity).

The oxygen-free copper plate preferably has an oxygen (O) concentration of 0 ppm, that is, an oxygen content of zero, from the viewpoint of suppressing a decrease in conductivity. However, since impurities are inevitably mixed in the oxygen-free copper plate in the process of manufacturing the oxygen-free copper plate, it is difficult to reduce the O concentration in the oxygen-free copper plate to zero, and oxygen of several to several tens of ppm is contained. It is generally included. In the present embodiment, the O concentration in the oxygen-free copper plate may be 10 ppm or less, which makes it suitable for use in the ceramic wiring board described later.

The oxygen-free copper plate has one or more elements selected from the group consisting of tin (Sn), zirconium (Zr), magnesium (Mg), titanium (Ti) and calcium (Ca) (hereinafter, these are collectively referred to as "Sn". It is preferable that the element (also referred to as "elements such as") is contained.

The atomic radii of the above-mentioned elements are Sn: 158 pm, Zr: 160 pm, Mg: 160 pm, Ti: 147 pm, and Ca: 197 pm, respectively, which are much larger than the atomic radius of 128 pm of copper (Cu). Therefore, the crystal lattice (atomic lattice) can be greatly distorted by dissolving an element such as Sn in the parent phase of copper. When the oxygen-free copper plate is heated at a high temperature, this strain hinders the movement of grain boundaries, and as a result, the crystal coarsening due to the high temperature heating can be suppressed.

The concentration (content) of an element such as Sn is preferably, for example, 150 ppm or less, and more preferably 50 ppm or more and 150 ppm or less. When two or more kinds of elements selected from the group consisting of Sn and the like are contained in the oxygen-free copper plate, the total concentration (total concentration) of the two or more kinds of elements is preferably 150 ppm or less.

When the concentration (total concentration) of an element such as Sn exceeds 150 ppm, the decrease in the conductivity of the oxygen-free copper plate becomes large. For example, the conductivity of an oxygen-free copper plate containing an element such as Sn is lower than the conductivity of an oxygen-free copper plate containing (adding) an element such as Sn by more than 3% IACS. By setting the concentration of an element such as Sn to 150 ppm or less, it is possible to suppress a decrease in conductivity while obtaining the above-mentioned effect of suppressing crystal coarsening by an element such as Sn. The conductivity of the oxygen-free copper plate can be, for example, 100% IACS or higher.

If the concentration of an element such as Sn is less than 50 ppm, the crystal lattice cannot be sufficiently distorted, and the above-mentioned effect of suppressing crystal coarsening by the element such as Sn may not be sufficiently obtained. By setting the concentration of an element such as Sn to 50 ppm or more, the above-mentioned effect of suppressing crystal coarsening by the element such as Sn can be sufficiently obtained.

(2) Method for Manufacturing Oxygen-Free Copper Plate Next, a method for manufacturing the oxygen-free copper plate according to the present embodiment will be described by sequentially performing steps 1 to 5 shown below.

(Step 1: Casting)
Oxygen-free copper as a raw material is melted using a high-frequency melting furnace or the like to produce a solution of oxygen-free copper. A predetermined amount of elements such as Sn, Zr, Mg, Ti, and Ca may be added to the solution of oxygen-free copper. In this case, the amount of the element such as Sn added is adjusted so that the concentration (total concentration) of the element such as Sn in the finally formed oxygen-free copper plate is, for example, 150 ppm or less, preferably 50 ppm or more and 150 ppm or less. .. The molten oxygen-free copper (solution of oxygen-free copper) is poured into a mold and cooled to cast an ingot having a predetermined thickness and a predetermined width.

(Step 2: Hot rolling)
The ingot is heated to a predetermined temperature (for example, 900 ° C. or higher and 1000 ° C. or lower), hot-rolled to a predetermined temperature, and hot-rolled to a predetermined thickness (for example, 10 to 15 mm). To get. The hot-rolled material in the present specification refers to an oxygen-free copper plate material formed by hot-rolling.

(Step 3: Cold rolling)
For the hot-rolled material, cold rolling with a predetermined degree of processing and annealing (intermediate annealing) in which the material to be processed is heated for a predetermined time under a predetermined temperature condition are alternately repeated a predetermined number of times. This intermediate annealing is a process of relaxing work hardening by annealing the work material that has been work-hardened by cold rolling. Step 3 may be completed by cold rolling after alternately performing cold rolling and intermediate annealing a predetermined number of times. By performing step 3, a cold-rolled material having a predetermined thickness is obtained. The thickness of the cold-rolled material is adjusted to a thickness at which the oxygen-free copper plate after performing step 5 (final cold-rolling) described later becomes a predetermined thickness. The cold-rolled material in the present specification refers to an oxygen-free copper plate material after the completion of this step (after performing cold rolling and annealing treatment a predetermined number of times), and this is also referred to as a so-called dough. It is a copper strip called.

(Step 4: Annealing the dough)
The cold-rolled material, that is, the dough is annealed (dough annealing) by heating at a predetermined temperature for a predetermined time to obtain an annealed dough. The dough annealing is carried out under conditions (temperature, time) that can sufficiently alleviate the processing strain accumulated in the cold-rolled material by, for example, the above-mentioned hot rolling or cold rolling.

(Step 5: Final cold rolling)
The cold-rolled material (that is, the annealed dough) that has been annealed the dough is subjected to cold rolling different from the cold rolling in step 3 above a predetermined number of times (preferably a plurality of times) (final cold rolling, finish cold rolling). Rolling between them) to form a flat plate-shaped oxygen-free copper plate having a predetermined thickness (for example, 100 μm or more). In this step, it is preferable to continuously perform cold rolling a plurality of times without annealing (heat treatment).

During rolling, the material to be rolled (object to be processed, material to be processed) such as annealed dough is reduced in thickness by passing between a pair of rolling rolls (hereinafter, also referred to as rolls) facing each other. The speed of the material to be rolled passing between the rolls is slower than the rotation speed of the roll before being drawn into the roll (roll inlet side) and faster than the rotation speed of the roll after being drawn out from the roll (roll outlet side). Therefore, during rolling, compressive stress is likely to be applied to the material to be rolled on the roll inlet side, and tensile stress is likely to be applied to the roll outlet side. In order to reduce the thickness of the material to be rolled, it is necessary to make the compressive stress higher than the tensile stress applied to the material to be rolled (compressive stress> tensile stress).

In step 5, cold rolling (rolling pass) in which the degree of processing once (1 pass) is a predetermined degree of processing is performed, for example, the total processing degree is, for example, 40% or more, preferably 80% or less, more preferably 50% or more 75. Repeat multiple times so that it is less than%.

The total degree of processing is obtained from the following (Equation 1). In (Equation 1), TB is the thickness of the material to be treated (annealed dough) before the final cold rolling, and TA is the material to be treated (that is, oxygen-free copper plate) after the final cold rolling. Is the thickness of.
(Number 1)
Total degree of processing (%) = [(TB-TA) / TB] x 100

If the total degree of processing is less than 40%, the strain energy stored inside the finally obtained oxygen-free copper plate becomes insufficient. Therefore, even when the oxygen-free copper plate satisfies all of the above formulas (1) to (12), it may not be possible to suppress crystal coarsening due to high temperature heating. By setting the total processing degree to 40% or more, sufficient strain energy can be accumulated inside the oxygen-free copper plate, and by setting the total processing degree to 50% or more, more strain is generated inside the oxygen-free copper plate. Energy can be stored and the above problems can be solved.

The copper crystals in the material to be rolled cause a rotation phenomenon due to the stress applied to the material to be rolled during rolling, and the crystal plane changes. For example, in this step, the copper crystals in the material to be rolled are cold-rolled via crystal planes such as {002} plane, {113} plane, {111} plane, and {133} plane, for example, as follows. It rotates (changes) to the {022} plane through the paths 1 and 2. The greater the stress applied to the material to be rolled, that is, the higher the total degree of processing, the more crystals rotate to the {022} plane.
Route 1: {113} plane → {002} plane → {022} plane Route 2: {111} plane → {133} plane → {022} plane

Therefore, when the total workability of cold rolling in step 5 exceeds 80%, many crystals rotate to the {022} plane, so that many crystals of the {022} plane are present in the oxygen-free copper plate. .. Therefore, for example, even when the degree of processing per pass and the position of the neutral point are controlled as described later, the oxygen-free copper plate does not satisfy at least one of the above formulas (1) to (12). There is. The above-mentioned problem can be solved by setting the total processing degree to 80% or less, and the above-mentioned problem can be surely solved by setting the total processing degree to 75% or less.

Further, in this step, it is preferable to adjust the degree of processing per pass in addition to the total degree of processing. The degree of processing per pass is preferably, for example, 20% or more, which is a predetermined degree of processing. As a result, the strength (magnitude) of the compressive stress applied to the material to be rolled and the strength (magnitude) of the tensile stress are adjusted in each pass so that compressive stress> tensile stress, and the stress component (compressive component and tensile component). The ratio can be adjusted.

By adjusting the ratio of the stress component applied to the material to be rolled in each pass, it is possible to change the path when the copper crystals in the material to be rolled change to the {022} plane by cold rolling. When the ratio of the compression component added to the material to be rolled (hereinafter, also referred to as “compression component ratio”) becomes high, it becomes easier to pass through the above path 1, and the ratio of the tension component added to the material to be rolled (hereinafter, also referred to as “tension component ratio”). ) Is higher, it becomes easier to pass through the above route 2.

By setting conditions that make it easy to pass through the path 1, for example, by controlling the degree of processing per pass so that the compression component ratio becomes high while compressing component> tensile component, it exists in the oxygen-free copper plate {002 The amount (number) of crystals on the} plane and {113} plane can be increased. Under the condition that it is easy to pass through the path 1, the amount of crystals on the {002} plane existing in the oxygen-free copper plate can be increased by setting the condition that the compression component ratio is high, and the tensile component ratio becomes high (compression). The amount of crystals on the {113} plane present in the oxygen-free copper plate can be increased by setting the condition (the component ratio becomes low).

By making the conditions easy to pass through the path 2, for example, by controlling the degree of processing per pass so that the compression component> the tensile component and the tensile component ratio become high, it exists in the oxygen-free copper plate {111. The amount (number) of crystals on the} plane and {133} plane can be increased. Under the condition that it is easy to pass through the path 2, the amount of crystals on the {111} plane existing in the oxygen-free copper plate can be increased by setting the condition that the tensile component ratio is high, and the compression component ratio becomes high (tensile). The amount of crystals on the {133} plane present in the oxygen-free copper plate can be increased by setting the condition (the component ratio becomes low).

For the direction of change, for example, the following document (a) was referred to.
(A) ed. Author Shinichi Nagashima, "Aggregate Organization", Maruzen Co., Ltd., January 20, 1984, p96, Figure 2.52

Further, in step 5, it is preferable to control the position of the neutral point in each path. For example, it is preferable to set the position of the neutral point on the roll outlet side as the thickness of the material to be rolled becomes thinner, that is, the path in the latter stage (lower stage). The neutral point is a position where the speed of the material to be rolled passing between the rolls becomes equal to the rotation speed of the rolls. As described above, the speed of the material to be rolled passing between the rolls is slower than the rotation speed of the roll on the roll inlet side and faster than the roll rotation speed on the roll outlet side. At the neutral point, the pressure applied to the material to be rolled is maximum.

By controlling the position of the neutral point, the strength of compressive stress, the strength of tensile stress, and the ratio of stress components can be adjusted. The higher the strength of the compressive stress applied to the material to be rolled, the easier it is for the copper crystals in the material to be rolled to rotate to the {022} plane. Further, if the ratio of the compressed component added to the material to be rolled is increased, the amount of crystals on the {002} plane and {113} plane present in the oxygen-free copper plate can be increased, and if the ratio of the compressed component is lowered, the oxygen-free copper plate can be used. As described above, it is possible to increase the amount of crystals on the {111} plane and the {133} plane present in the surface.

By setting the position of the neutral point on the roll outlet side, it is possible to increase the strength of the compressive stress applied to the material to be rolled and increase the compression component ratio. By setting the position of the neutral point on the roll inlet side, it is possible to lower the strength of the compressive stress applied to the material to be rolled and lower the compression component ratio.

The position of the neutral point can be controlled, for example, by adjusting the rolling speed (rotational speed of the roll). For example, when other conditions such as the degree of machining per pass are constant, if the rolling speed is increased, the position of the neutral point can be moved to the rear side (entrance side) with respect to the traveling direction, and the rolling speed can be increased. If it is lowered, the position of the neutral point can be moved to the front side (exit side) with respect to the traveling direction.

In addition to the rolling speed, the position of the neutral point can be controlled by controlling the forward tension, the backward tension, the roll diameter, the degree of processing, the surface roughness of the roll, the rolling load, and the like. Only one of these control factors may be variable, or a plurality of factors may be variable. That is, a plurality of methods can be considered for controlling the position of the neutral point.

In addition, the above-mentioned control factors are related to the configuration of the rolling mill. For example, how the compressive stress is applied to the material to be rolled depends on the difference in the number of roll stages, the total number of rolls, the combination arrangement of rolls, the roll composition such as the diameter, material and surface condition (surface roughness) of each roll. There is a difference in the coefficient of friction and the like. Therefore, the absolute value of the above-mentioned control factor differs depending on the rolling mill. As described above, since the control of the position of the neutral point largely depends on the specifications of the rolling mill, it is preferable to appropriately adjust the position for each rolling mill.

The position of the neutral point can be obtained by calculation with reference to reference (b), for example.
(B) Japan Society for Plastic Working, "Plastic Working Technology Series 7 Plate Rolling", Corona Publishing Co., Ltd., p14, p27 formula (3.3), p28

Further, in step 5, in each roll, control is performed so that the position of the neutral point does not move during cold rolling, for example, the position of the neutral point does not move to the outlet side of the roll. Is preferable.

(3) Configuration of Ceramic Wiring Board and Manufacturing Method thereof The configuration of the ceramic wiring board using the oxygen-free copper plate according to the above-described embodiment and the manufacturing method thereof will be described.

The ceramic wiring board according to the present embodiment includes a ceramic substrate having a predetermined thickness (for example, 0.5 mm) and a wiring material made of the above-mentioned oxygen-free copper plate provided on the ceramic substrate. The ceramic substrate and the wiring material are bonded (bonded) to each other via, for example, a brazing material. A predetermined portion of the oxygen-free copper plate is removed by etching, for example, to form a wiring pattern (copper wiring). As the ceramic substrate, for example, a ceramic sintered body containing aluminum nitride (AlN), silicon nitride (SiN), or the like as a main component can be used. As the brazing material, for example, a metal such as silver (Ag), Cu, Sn, indium (In), Ti, molybdenum (Mo), carbon (C), or a metal alloy containing at least one of these metals is used. be able to.

The ceramic wiring board described above can be manufactured, for example, by the following procedure. First, the surface of the ceramic substrate is cleaned. For example, the ceramic substrate is heated to a predetermined temperature (for example, 800 ° C. to 1080 ° C.) to remove organic substances and residual carbon adhering to the surface of the ceramic substrate. Then, for example, a paste-like brazing material is applied onto one of the main surfaces of the ceramic substrate by a screen printing method. Subsequently, an oxygen-free copper plate is placed on the brazing material, and the laminate of the oxygen-free copper plate, the ceramic substrate, and the brazing material is heated at a predetermined temperature (for example, 800 ° C. or higher and 1080 ° C. or lower) for a predetermined time (for example, 5 minutes or longer). Then, the oxygen-free copper plate and the ceramic substrate are bonded together via a brazing material. This heating is preferably performed in vacuum, in a reducing gas atmosphere or in an inert gas atmosphere.

(4) Effects of the present embodiment According to the present embodiment, one or more of the following effects are exhibited.

(A) The oxygen-free copper plate according to the present embodiment, that is, the oxygen-free copper plate after passing through step 5 and before being heated at a high temperature, satisfies all of the above formulas (1) to (12). That is, the oxygen-free copper plate according to the present embodiment is an oxygen-free copper plate in which there are few crystals on the {022} plane and a certain amount of crystals on each crystal plane in the sub-direction are present. As a result, even when the oxygen-free copper plate is heated at a high temperature, it is possible to suppress the coalescence aggregation of the crystal grains (recrystallized grains) in the oxygen-free copper plate and suppress the coarsening of the crystals. The oxygen-free copper plate according to the present embodiment can suppress the coarsening of crystals even when it is heated at a high temperature at the time of joining with a ceramic substrate, for example. For example, the oxygen-free copper plate according to the present embodiment has an average crystal grain size of 0.4 mm or less even after being heat-treated by heating under the condition of 900 ° C. for 10 minutes.

(B) Even if it is a copper plate having few impurities, that is, an oxygen-free copper plate, it is possible to suppress crystal coarsening due to high-temperature heating by satisfying all of the above formulas (1) to (12).

(C) By including an element such as Sn in the oxygen-free copper plate, crystal coarsening due to high-temperature heating can be reliably suppressed.

(D) By suppressing crystal coarsening due to high-temperature heating, the oxygen-free copper plate can be particularly suitably applied to applications of wiring materials for ceramic wiring boards.

Since the crystal coarsening due to high temperature heating is suppressed, when inspecting the ceramic wiring board having the oxygen-free copper plate according to the present embodiment using a CCD camera or the like, the crystal grain boundaries and the inspection surface of the ceramic wiring board are present. It becomes easy to distinguish from foreign matter and scratches. Therefore, the inspection accuracy can be improved.

In addition, since the crystal roughness due to high temperature heating is suppressed, the surface roughness of the oxygen-free copper plate increases due to the coarsened recrystallized grains, that is, the numerical value of the surface roughness of the oxygen-free copper plate increases. It can be suppressed. Therefore, it is possible to suppress a decrease in the bonding strength between the wire used when mounting the semiconductor element on the ceramic wiring board and the ceramic wiring board.

(E) When the thickness of the oxygen-free copper plate is, for example, 100 μm or more, the oxygen-free copper plate can be suitably applied as a wiring material for a ceramic wiring board.

(F) By setting the copper purity of the oxygen-free copper plate to 99.96% or more, the O concentration of the oxygen-free copper plate to 10 ppm or less, and the concentration of elements such as Sn to 150 ppm or less, the oxygen-free copper plate can be used. The conductivity can be, for example, 100% IACS or higher. This makes it possible to suitably apply the oxygen-free copper plate as a wiring material for a ceramic wiring board. From the viewpoint of surely preventing a decrease in the conductivity of the oxygen-free copper plate, it is preferable that all of the above-mentioned purity of copper, O concentration and concentration of elements such as Sn satisfy the above ranges.

(G) By controlling the processing conditions (machining conditions) of step 5 (final cold rolling) so that the oxygen-free copper plate satisfies all of the above formulas (1) to (12), the cold rolling of step 5 is performed. Even when the total degree of processing is 40% or more, that is, an oxygen-free copper plate in which crystal coarsening due to high-temperature heating is suppressed can be obtained without lowering the total degree of processing.

(H) By setting the total workability of cold rolling in step 5 to 40% or more, sufficient strain energy can be accumulated inside the oxygen-free copper plate, and as a result, the oxygen-free copper plate is heated at a high temperature. When recrystallization occurs, the frequency of recrystallization nuclei can be increased (the number of recrystallized nuclei generated can be increased). As a result, even when the oxygen-free copper plate is heated at a high temperature, a desired number of crystals can be present in the oxygen-free copper plate, and coarsening of the crystals can be reliably suppressed.

(I) By setting the total workability of cold rolling in step 5 to 80% or less, it is possible to reduce the number of crystals rotating to the {022} plane, and as a result, a desired amount (desired) in the oxygen-free copper plate. Crystals on each crystal plane in the sub-direction of number) can be present (remained). Therefore, it becomes easy to control the ratio of crystals on each crystal plane in the sub-direction in the oxygen-free copper plate, and an oxygen-free copper plate satisfying the above formulas (1) to (12) can be easily obtained.

(J) By controlling the degree of processing per pass in step 5, it is possible to adjust the path when the copper crystal in the material to be rolled changes to the {022} plane by cold rolling. As a result, it is possible to control the ratio of crystals on each crystal plane in the sub-direction in the oxygen-free copper plate. That is, the number of crystals on the {022} plane in the oxygen-free copper plate can be reduced, and the crystals on the crystal plane in the sub-direction in the oxygen-free copper plate can be easily adjusted to the optimum value.

(K) By controlling the position of the neutral point of each path in step 5, it is possible to reduce the number of crystals rotating to the {022} plane and control the ratio of crystals on each crystal plane in the sub-direction. That is, the ratio of the crystals on the {022} plane and the crystal plane in the sub-direction in the oxygen-free copper plate can be easily adjusted to be the optimum value. As a result, it becomes possible to more easily obtain an oxygen-free copper plate satisfying all of the above formulas (1) to (12).

(L) In step 5, by controlling the degree of processing per pass and the position of the neutral point of each pass, the ratio of crystals on the {022} plane and each crystal plane in the sub-direction in the oxygen-free copper plate is precise. Can be controlled to.

(M) In step 5, the strength of the compressive stress applied to the material to be rolled and the strength of the tensile stress are controlled by controlling the position of the neutral point so as not to move during cold rolling in each roll. It is possible to reliably control the ratio of stress components.

<Other embodiments>
Although one embodiment of the present invention has been specifically described above, the present invention is not limited to the above-described embodiment and can be appropriately modified without departing from the gist thereof.

In the above-described embodiment, the case where the oxygen-free copper plate is produced by carrying out steps 1 to 5 has been described as an example, but the present invention is not limited to this. For example, steps 1 to 4 may be omitted as appropriate depending on the intended use.

Further, for example, after step 5, a heat treatment (recrystallization heat treatment) may be performed in which the oxygen-free copper plate obtained in step 5 is heated at a predetermined temperature for a predetermined time as step 6. The oxygen-free copper plate according to the present invention can prevent the crystals in the oxygen-free copper plate from becoming coarse even when such recrystallization heat treatment is performed. Further, even if the oxygen-free copper plate after step 6 is heated at a high temperature at the time of joining to the ceramic substrate, the coarsening of crystals can be suppressed.

In the above-described embodiment, a case where the oxygen-free copper plate and the ceramic substrate are joined by an active metal brazing method at the time of manufacturing the ceramic wiring board has been described as an example, but the joining is not limited to this, and the joining thereof is, for example. It may be performed by the direct bonding method.

Further, the oxygen-free copper plate according to the present invention is not limited to the case where it is used as a wiring material for a ceramic wiring board as described above. In addition, the oxygen-free copper plate according to the present invention can be suitably applied to applications that require suppression of crystal coarsening when heated at 800 ° C. or higher.

Next, examples of the present invention will be described, but the present invention is not limited thereto.

<Preparation of sample>
(Sample 1)
First, a billet having a predetermined shape was cast by a continuous casting method. Specifically, an oxygen-free copper as a raw material was melted using a melting furnace to produce a solution of oxygen-free copper. A predetermined amount of Sn was added to the solution so that the concentration of Sn in the finally formed oxygen-free copper plate was 80 ppm, and the molten metal was melted. This molten metal was poured into a mold having a predetermined shape to cast an ingot having a thickness of 150 mm and a width of 500 mm. The obtained ingot was hot-rolled to obtain a plate material (hot-rolled material) having a thickness of 8 mm. The obtained hot-rolled material is alternately subjected to predetermined cold rolling and intermediate annealing in which the material to be treated is held at a temperature of 650 to 750 ° C. for 2 minutes and heated by alternately performing cold rolling a predetermined number of times. A rolled material (dough) was obtained. The thickness of the dough was set so that the oxygen-free copper plate at the end of the final cold rolling to be carried out later had a desired thickness. The thickness of the dough was adjusted by adjusting the degree of cold rolling. Then, the obtained dough was subjected to annealing (dough annealing) by holding it at a temperature of 700 ° C. for 1 minute and heating it to obtain an annealed dough.

The final cold rolling was performed on the annealed dough by continuously performing cold rolling a plurality of times (multiple passes) without sandwiching the annealing. The conditions for each pass of the final cold rolling are shown in Table 1 below. As shown in FIG. 1, the “neutral point position (mm)” shown in Table 1 is from the outlet side end on the contact surface of the material to be rolled (working object) passing between the pair of rolls. The length L to the neutral point. That is, the smaller the value of the position of the neutral point shown in Table 1, the more the neutral point is located on the roll exit side.

Each time the rolling pass is passed, the material to be rolled is reduced in thickness. Therefore, in the final cold rolling, as shown in Table 1, the degree of processing per pass and the position of the neutral point are set for each pass according to the thickness of the material to be rolled having a thickness of 1 mm or less. Adjusted to. At this time, the position of the neutral point was controlled so that the position of the neutral point was located on the roll exit side from the upper stage (front stage) to the lower stage (rear stage). By performing such final cold rolling, an oxygen-free copper plate having a thickness of 0.3 mm was obtained. This was used as sample 1.

(Samples 2 to 20)
In Samples 2 to 20, elements such as Sn added to the molten metal so that the concentration of the element selected from the group consisting of Sn, Zr, Mg, Ti and Ca in the oxygen-free copper plate is as shown in Table 2. The amount of addition was adjusted. The conditions for each pass of the final cold rolling were as shown in Table 1, and the total workability of the final cold rolling was as shown in Table 2. Further, the samples 2 to 20 change the degree of processing per pass and the position of the neutral point within the ranges shown in Tables 1 and 2, respectively, and the compressive stress applied to the material to be rolled during the final cold rolling. The strength, the strength of the tensile stress, and the stress component (that is, the ratio of the compression component to the tensile component) are changed. Other than that, an oxygen-free copper plate was prepared under the same manufacturing method and conditions as in Sample 1 described above. These were used as samples 2 to 20, respectively.

The composition of the oxygen-free copper plates of Samples 1 to 20 and the total degree of processing of the final cold rolling are summarized in Table 2 below. The additive element concentrations shown in Table 2 are the results of concentration analysis of the additive elements by the high frequency inductively coupled plasma emission spectroscopy.

<Evaluation>
For each of the samples 1 to 20, X-ray diffraction measurement by the 2θ / θ method, evaluation of crystal coarsening after high temperature heating, and evaluation of conductivity after high temperature heating were performed.

(X-ray diffraction measurement by 2θ / θ method)
In each of the samples 1 to 20, X-ray diffraction measurement was performed on the rolled surface of each sample by the 2θ / θ method. The measurement was carried out using an X-ray diffractometer (model: Ultima IV) manufactured by Rigaku Co., Ltd. under the conditions shown in Table 3 below.

Table 4 shows the diffraction peak intensities (I _{ I {) of the {022} plane, {002} plane, {113} plane, {111} plane, and {133} plane measured by X-ray diffraction measurement by the 2θ / θ method of each sample. _022} , I _{002} , I _{113} , I _{111} , I _{133} ). In addition, the values of the above equations (1) to (12) were calculated using the values of these diffraction peak intensities. The calculation results are shown in Table 4.

As shown in Table 4, it can be confirmed that the diffraction peak intensities of the respective crystal planes are different in the samples 1 to 20. From this, by changing the workability per pass and the position of the neutral point, and changing the strength of compressive stress, the strength of tensile stress, and the stress component applied to the material to be rolled during the final cold rolling, nothing is done. It can be seen that the ratio of crystals on the {022} plane and each crystal plane in the sub-direction in the copper oxygen plate can be changed.

(Evaluation of crystal coarsening after high temperature heating)
The evaluation of crystal coarsening after high temperature heating was performed by the following procedure. First, 20 mm square test pieces were cut out from each of the samples 1 to 20, and these test pieces were heated in a nitrogen gas atmosphere under a temperature condition of 900 ° C. for 10 minutes. After polishing with abrasive paper and alumina abrasive grains until the rolled surface of each sample after heating becomes a mirror surface, the surface of each sample is etched with aqueous ammonia containing hydrogen peroxide to form the rolled surface of each sample. A crystal grain boundary was made to appear. The crystal grain size (average crystal grain size) was measured for each sample in which the grain boundaries appeared, using the cutting method specified in JIS H0501. The measurement results of the crystal grain size are shown in Table 5 below. Further, a sample having a crystal grain size of 0.4 mm or less is judged to be acceptable (○), and a sample having a crystal grain size of more than 0.4 mm is judged to be rejected (×), and the judgment results are also shown in Table 5 below. show.

From Samples 1 to 12, 16 to 20, it can be confirmed that crystal coarsening due to high temperature heating can be suppressed by satisfying all of the formulas (1) to (12).

Sample 2 having a low concentration of elements such as Sn (almost no element such as Sn is added) is heated at a higher temperature than Samples 1, 3 to 12, 16 to 20 having a concentration of elements such as Sn of 50 ppm or more. It can be confirmed that the later crystal grain size is increased. From this, it can be confirmed that adding an element such as Sn can reliably suppress crystal coarsening due to high-temperature heating.

Since the sample 13 does not satisfy all of the formulas (1) to (12), it can be confirmed that the crystals are coarsened by high temperature heating. In sample 13, since the values of I _{022} , I _{002} , and I _{113} are high, the strength of the compressive stress applied to the material to be rolled during the final cold rolling and the compression component ratio are high. You can see that. That is, even if the total workability of the final cold rolling is 80% or less, the strength of the compressive stress applied to the material to be rolled depends on the workability per pass of the final cold rolling and the condition of the position of the neutral point. It can be confirmed that the strength of the tensile stress and the ratio of the stress components change, and as a result, the equations (1) to (12) may not be satisfied.

From sample 14, if the total workability of the final cold rolling is less than 40%, it may not be possible to suppress crystal coarsening due to high temperature heating even when all of the above formulas (1) to (12) are satisfied. It can be confirmed that there is. It is considered that this is because the frequency of recrystallization nuclei generated when the oxygen-free copper plate is heated to a high temperature and recrystallization occurs is low.

From sample 15, if the total workability of the final cold rolling exceeds 80%, all of the above formulas (1) to (12) may not be satisfied, and crystal coarsening due to high temperature heating may not be suppressed. Can be confirmed. In this case, since the value of I _{022} is high, it can be seen that many crystals have rotated to the {022} plane by the final cold rolling.

(Evaluation of conductivity after high temperature heating)
The conductivity after high temperature heating was evaluated by the following procedure. First, 50 mm square test pieces were cut out from each of the samples 1 to 20, and these test pieces were heated in a nitrogen gas atmosphere for 10 minutes under a temperature condition of 900 ° C. Then, the conductivity of each test piece after heating was measured using a sigma test, which is a perfusion type conductivity meter manufactured by Felster. The measurement results of the conductivity are shown in Table 5 above. Further, a sample having a conductivity of 100% IACS or more is judged to be excellent (⊚), and a sample having a conductivity of 95% IACS or more and less than 100% IACS is judged to be good (◯), and the judgment result is also in the above table. Shown in 5.

From Table 5, it can be confirmed that in the samples 1 to 15, when the concentration of the element such as Sn in the oxygen-free copper plate is 150 ppm or less, the decrease in the conductivity of the oxygen-free copper plate can be suppressed. For example, it can be confirmed that the conductivity of the oxygen-free copper plate is 100% IACS or more. Such an oxygen-free copper plate is more preferable as a conductor of a ceramic wiring board.

From Table 5, in Samples 16 to 20, when the concentration of an element such as Sn in the oxygen-free copper plate exceeds 150 ppm, the conductivity of the oxygen-free copper plate becomes less than 100% IACS, and the conductivity of the oxygen-free copper plate decreases. Can be confirmed.

<Preferable aspect>
Hereinafter, preferred embodiments of the present invention will be described.

[Appendix 1]
According to one aspect of the invention
By rolling, it is formed into a flat plate,
It has a crystal whose crystal planes parallel to the rolled plane are {022} plane, {002} plane, {113} plane, {111} plane and {133} plane.
The diffraction peak intensities of each of the crystal planes obtained by the X-ray diffraction measurement by the 2θ / θ method for the rolled surface are I _{022} , I _{002} , I _{113} , I _{111} , I _{133} , respectively. When
I _{022} / (I _{022} + I _{002} + I _{113} + I _{111} + I _{133} ) ≤ 0.3.
(I _{002} + I _{113} ) / (I _{111} + I _{133} ) ≧ 1.0, and
I _{002} / I _{022} ≧ 1.0,
I _{113} / I _{022} ≧ 0.5,
I _{111} / I _{022} ≧ 0.15,
I _{133} / I _{022} ≧ 0.02,
0.5 ≤ I _{002} / I _{113} ≤ 5.0.
0.2 ≤ I _{133} / I _{111} ≤ 0.5,
1.0 ≤ I _{113} / I _{111} ≤ 10
1.0 ≤ I _{002} / I _{111} ≤ 20
1.0 ≤ I _{002} / I _{133} ≤ 75,
1.0 ≤ I _{113} / I _{133} ≤ 30.
An oxygen-free copper plate having an average crystal grain size of 0.4 mm or less after being heat-treated by heating at 900 ° C. for 10 minutes is provided.

[Appendix 2]
The oxygen-free copper plate of Appendix 1, preferably
It contains at least one selected from the group consisting of Sn, Zr, Mg, Ti and Ca, with the balance consisting of copper and unavoidable impurities.

[Appendix 3]
The oxygen-free copper plate of Appendix 1 or 2, preferably
It contains one or more selected from the group consisting of Sn, Zr, Mg, Ti and Ca so that the total concentration is 150 ppm or less, preferably 50 ppm or more and 150 ppm or less.

[Appendix 4]
It is an oxygen-free copper plate according to any one of Supplementary note 1 to 3, preferably.
The conductivity is 100% IACS or higher.

[Appendix 5]
According to another aspect of the invention.
A cold rolling process of forming a cold rolled material by repeating cold rolling and annealing for the material to be treated a predetermined number of times,
Provided is a method for manufacturing an oxygen-free copper plate, which comprises a final cold-rolling step of cold-rolling the cold-rolled material with a total workability of 40% or more to form a flat plate-shaped oxygen-free copper plate. Will be done.

[Appendix 6]
The method of Appendix 5, preferably
In the final cold rolling step, cold rolling with a total workability of 40% or more and 80% or less is performed.

[Appendix 7]
The method of Appendix 5 or 6, preferably
In the final cold rolling step, the workability of each pass is adjusted to adjust the strength of compressive stress, the strength of tensile stress, and the ratio of stress components applied to the material to be rolled by each pass.

[Appendix 8]
The method of Appendix 7, preferably
In the final cold rolling step, the workability of each pass is set to 20% or more.

[Appendix 9]
The method according to any one of Supplementary Provisions 5 to 8, preferably.
In the final cold rolling step, the strength of the compressive stress, the strength of the tensile stress, and the ratio of the stress components applied to the material to be rolled by each pass are adjusted by adjusting at least one of the positions of the neutral points.

[Appendix 10]
The method of Appendix 9, preferably
In the final cold rolling step, the neutral point is controlled to be located on the outlet side of the pair of rolling rolls as the thickness of the material to be rolled becomes thinner.

[Appendix 11]
The method according to any one of Supplementary Provisions 5 to 10, preferably.
In the final cold rolling step,
It has a crystal whose crystal planes parallel to the rolled plane are {022} plane, {002} plane, {113} plane, {111} plane and {133} plane.
The diffraction peak intensities of each of the crystal planes obtained by X-ray diffraction measurement by the 2θ / θ method for the rolled surface are I _{022} , I _{002} , I _{113} , I _{111} and I _{133} , respectively. When
I _{022} / (I _{022} + I _{002} + I _{113} + I _{111} + I _{133} ) ≤ 0.3.
(I _{002} + I _{113} ) / (I _{111} + I _{133} ) ≧ 1.0, and
I _{002} / I _{022} ≧ 1.0,
I _{113} / I _{022} ≧ 0.5,
I _{111} / I _{022} ≧ 0.15,
I _{133} / I _{022} ≧ 0.02,
0.5 ≤ I _{002} / I _{113} ≤ 5.0.
0.2 ≤ I _{133} / I _{111} ≤ 0.5,
1.0 ≤ I _{113} / I _{111} ≤ 10
1.0 ≤ I _{002} / I _{111} ≤ 20
1.0 ≤ I _{002} / I _{133} ≤ 75,
1.0 ≤ I _{113} / I _{133} ≤ 30.
An oxygen-free copper plate having an average crystal grain size of 0.4 mm or less after heat treatment under the condition of 900 ° C. for 10 minutes is formed.

[Appendix 12]
The method according to any one of Supplementary Provisions 5 to 11, preferably.
It further comprises a step of casting an ingot containing at least one selected from the group consisting of Sn, Zr, Mg, Ti and Ca.

[Appendix 13]
The method of Appendix 12, preferably
In the step of casting the ingot, one or more selected from the group consisting of Sn, Zr, Mg, Ti and Ca are added so that the concentration thereof is 150 ppm or less, preferably 50 ppm or more and 150 ppm or less.

[Appendix 14]
According to still another aspect of the invention.
Ceramic substrate and
It is provided with an oxygen-free copper plate as a wiring material provided on the ceramic substrate, which is formed into a flat plate shape by rolling the oxygen-free copper.
The oxygen-free copper plate is
It has a crystal whose crystal planes parallel to the rolled plane are {022} plane, {002} plane, {113} plane, {111} plane and {133} plane.
The diffraction peak intensities of each of the crystal planes obtained by the X-ray diffraction measurement by the 2θ / θ method for the rolled surface are I _{022} , I _{002} , I _{113} , I _{111} , I _{133} , respectively. When
I _{022} / (I _{022} + I _{002} + I _{113} + I _{111} + I _{133} ) ≤ 0.3.
(I _{002} + I _{113} ) / (I _{111} + I _{133} ) ≧ 1.0, and
I _{002} / I _{022} ≧ 1.0,
I _{113} / I _{022} ≧ 0.5,
I _{111} / I _{022} ≧ 0.15,
I _{133} / I _{022} ≧ 0.02,
0.5 ≤ I _{002} / I _{113} ≤ 5.0.
0.2 ≤ I _{133} / I _{111} ≤ 0.5,
1.0 ≤ I _{113} / I _{111} ≤ 10
1.0 ≤ I _{002} / I _{111} ≤ 20
1.0 ≤ I _{002} / I _{133} ≤ 75,
1.0 ≤ I _{113} / I _{133} ≤ 30.
A ceramic wiring board having an average crystal grain size of 0.4 mm or less is provided.

Claims (4)

Oxygen-free copper containing 1 or more selected from the group consisting of Sn, Zr, Mg, Ti and Ca in a total concentration of 2 ppm or more and 170 ppm or less, the balance being copper and unavoidable impurities, and having a purity of 99.96% or more. Is rolled to form a flat plate,
It has a crystal whose crystal planes parallel to the rolled plane are {022} plane, {002} plane, {113} plane, {111} plane and {133} plane.
The diffraction peak intensities of each of the crystal planes obtained by the X-ray diffraction measurement by the 2θ / θ method for the rolled surface are I _{022} , I _{002} , I _{113} , I _{111} , I _{133} , respectively. When
0.1 ≤ I _{022} / (I _{022} + I _{002} + I _{113} + I _{111} + I _{133} ) ≤ 0.3.
(I _{002} + I _{113} ) / (I _{111} + I _{133} ) ≧ 1.0, and
I _{002} / I _{022} ≧ 1.0,
I _{113} / I _{022} ≧ 0.5,
I _{111} / I _{022} ≧ 0.15,
I _{133} / I _{022} ≧ 0.02,
0.5 ≤ I _{002} / I _{113} ≤ 5.0.
0.2 ≤ I _{133} / I _{111} ≤ 0.5,
1.0 ≤ I _{113} / I _{111} ≤ 10
1.0 ≤ I _{002} / I _{111} ≤ 20
1.0 ≤ I _{002} / I _{133} ≤ 75,
1.0 ≤ I _{113} / I _{133} ≤ 30.
An oxygen-free copper plate having an average crystal grain size of 0.4 mm or less after being heat-treated for 10 minutes under the condition of 900 ° C. The oxygen-free copper plate according to claim 1 , wherein one or more selected from the group consisting of Sn, Zr, Mg, Ti and Ca is contained so that the total concentration is 150 ppm or less. The oxygen-free copper plate according to claim 1 , wherein one or more selected from the group consisting of Sn, Zr, Mg, Ti and Ca is contained so that the total concentration is 50 ppm or more and 150 ppm or less. Ceramic substrate and
Oxygen-free copper containing 1 or more selected from the group consisting of Sn, Zr, Mg, Ti and Ca in a total concentration of 2 ppm or more and 170 ppm or less, the balance being copper and unavoidable impurities, and having a purity of 99.96% or more. It is provided with an oxygen-free copper plate as a wiring material provided on the ceramics substrate, which is formed into a flat plate shape by rolling.
The oxygen-free copper plate is
It has a crystal whose crystal planes parallel to the rolled plane are {022} plane, {002} plane, {113} plane, {111} plane and {133} plane.
The diffraction peak intensities of each of the crystal planes obtained by the X-ray diffraction measurement by the 2θ / θ method for the rolled surface are I _{022} , I _{002} , I _{113} , I _{111} , I _{133} , respectively. When
0.1 ≤ I _{022} / (I _{022} + I _{002} + I _{113} + I _{111} + I _{133} ) ≤ 0.3.
(I _{002} + I _{113} ) / (I _{111} + I _{133} ) ≧ 1.0, and
I _{002} / I _{022} ≧ 1.0,
I _{113} / I _{022} ≧ 0.5,
I _{111} / I _{022} ≧ 0.15,
I _{133} / I _{022} ≧ 0.02,
0.5 ≤ I _{002} / I _{113} ≤ 5.0.
0.2 ≤ I _{133} / I _{111} ≤ 0.5,
1.0 ≤ I _{113} / I _{111} ≤ 10
1.0 ≤ I _{002} / I _{111} ≤ 20
1.0 ≤ I _{002} / I _{133} ≤ 75,
1.0 ≤ I _{113} / I _{133} ≤ 30.
A ceramic wiring board having an average crystal grain size of 0.4 mm or less.

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