The specific embodiment
Below, the rolling Copper Foil that embodiments of the present invention are related is described.In addition, in the present invention, only otherwise special declaration, % represents quality %.
First, technological thought of the present invention is described.If make the roller roughness in final cold rolling become large so that copper foil surface is coarse, the treatability of Copper Foil improves, and falls into but become easy generation dish, and etching reduces.Can think, this be because, utilize the coarse roller in final cold rolling, on the thickness direction of Copper Foil, produce detrusion band, rolling further continues thereby the prosperity of detrusion band.
On the other hand, the known gimmick that improves glossiness (surface roughness) in order to obtain the bendability of Copper Foil all the time.Can think, this is because be difficult to produce detrusion band by utilizing the roller that roughness is low to carry out final cold rolling, becoming on the thickness direction of Copper Foil.But if improve the glossiness (reduction surface roughness) of Copper Foil, the treatability of Copper Foil reduces.
On the other hand, the inventor has found, final mill train at final cold rolling does not nearby make the surface of Copper Foil too coarse (for example, utilize the roller that roughness is low to carry out rolling), in the final mill train of final cold rolling, make the rough surface (for example, utilizing coarse roller to carry out rolling) of Copper Foil, thereby make final copper foil surface coarse, and reduce detrusion band, improve bendability, and surface etching characteristic becomes good.
Known, in the past, thought that the orientation of Copper Foil only depends on the roughness of copper foil surface always, but in fact the scale of the detrusion band of material internal affects etching and the degree of orientation (and dish falls into).And, in final cold rolling, if suppress fully the prosperity of shear band in can the mill train before final mill train, even if fine finishining copper foil surface cursorily in final mill train also can obtain the degree of orientation that makes etching good.
In addition, only with the value of the glossiness using all the time, can not grasp clearly the flourishing degree of above-mentioned shear band.; if although think that to make final copper foil surface coarse; and reduce detrusion band; oil hole is shallow and have a width of certain degree; and the Frequency in oil hole tails off (with reference to Fig. 1 (a)), but this is difficult to find expression in the glossiness of the rolling parallel direction RD vertical with the direction in oil hole.On the other hand, if from rolling right angle orientation TD, because oil hole has the width of certain degree, therefore be easy to grasp the shape in oil hole, the variation of frequency from parallel direction.
The relation of this kind of oil hole and glossiness is described with reference to Fig. 1.
First, Fig. 1 (a) represents the oil hole of the inventive example and the figure of the relation of glossiness, if measure glossiness G along rolling parallel direction RD
rD, locate catoptrical direction in oil hole and change and be not detected glossiness step-down.On the other hand, measuring glossiness G along rolling right angle orientation TD
tDsituation under, because extend along TD in oil hole, therefore to side, (RD direction) skew is also detected although locate catoptrical direction in oil hole, glossiness uprises., with G
rDcompare G
tDrelatively uprise, spend glossiness if measure aftermentioned 60, meet G60
rD/ G60
tDthe relation of < 0.8.
Then, Fig. 1 (b) represents the oil hole of the conventional example in the coarse situation of copper foil surface and the figure of the relation of glossiness, the degree of depth and length (Frequency) that copper foil surface becomes excessively coarse and oily hole increase, no matter along any one the mensuration glossiness in rolling parallel direction RD and rolling right angle orientation TD, catoptrically at oil hole place all change thereby be not detected glossiness step-down.In this case, with G
rDcompare G
tDstep-down relatively, spends glossiness if measure aftermentioned 60, meets G60
rD/ G60
tDthe relation of > 1.
On the other hand, Fig. 1 (c) represents the oil hole of the conventional example in situation that copper foil surface is level and smooth and the figure of the relation of glossiness, becomes shallow, therefore even measure glossiness G along rolling parallel direction RD because copper foil surface becomes too level and smooth thereby oil hole
rD, locate in oil hole catoptrical direction also become be difficult to change, glossiness uprises., with G
tDcompare G
rDrelatively uprise, spend glossiness, G60 if measure aftermentioned 60
rD/ G60
tDrelation approach 1 (, the anisotropy of RD and TD diminishes).But copper foil surface is coarse unlike Fig. 1 (b) of the coarse conventional example of copper foil surface, thereby is G60
rD/ G60
tD< 1.
Regulation and the composition of rolling Copper Foil of the present invention then, are described.
(1) glossiness G60
rD
Make the 60 ° of surperficial glossiness G60 that measure along rolling parallel direction RD
rDbe more than 100 and below 300.If G60
rDexceed 300, copper foil surface becomes too level and smooth, close property reduction when Copper Foil is manufactured and roller, or be difficult to process Copper Foil goods.On the other hand, if G60
rDbe less than 100, copper foil surface becomes too coarse, at material internal, the prosperity of detrusion band, thus become easy generation dish fall into, etching reduce.
(2)G60
RD/G60
TD
As mentioned above, nearby do not make the surface of Copper Foil too coarse at the final mill train of final cold rolling, in the final mill train of final cold rolling, make the rough surface of Copper Foil, thereby make final copper foil surface coarse, and reduce detrusion band, maintain bendability, and dish falls into and tails off.And, understand by the inventor's experiment (aftermentioned embodiment), in the less surface of this kind of detrusion band, G60
rD/ G60
tD< 0.8.Thereby, by the 60 ° of surperficial glossiness G60 that measure along rolling parallel direction
rDwith the 60 ° of surperficial glossiness G60 that measure along rolling right angle orientation
tDratio G60
rD/ G60
tDbe defined as and be less than 0.8.In addition adopt than being impact in order to offset overall glossiness.
If G60
rD/ G60
tD>=0.8, as above-mentioned Fig. 1 (b), it is too level and smooth that copper foil surface becomes, and when the manufacture of Copper Foil reduces with close property roller, or be difficult to process Copper Foil goods.In addition, if become G60 as above-mentioned Fig. 1 (c)
rD/ G60
tD> 1, copper foil surface becomes too coarse, and the prosperity of detrusion band thereby bendability reduce, or become and be easy to produce dish and fall into.
In addition, as making G60
rD/ G60
tDthe method of < 0.8, as described above, in final cold rolling, in mill train before final mill train, suppress the prosperity of shear band, in the mill train before the final mill train of final cold rolling, use the smaller roller of roughness (surface roughness Ra is for for example below 0.5 μ m) to carry out rolling.On the other hand, on the other hand, in the final mill train of final cold rolling, use the larger roller of roughness (surface roughness Ra is for for example more than 0.6 μ m) to carry out rolling, make the final copper foil surface obtaining coarse.
At this, in final cold rolling, if make the surperficial glossiness G60 measuring along rolling parallel direction in the stage before 1 mill train of final mill train
rDexceed 300,, in the mill train before the final mill train of final cold rolling, it is smoother that copper foil surface becomes, and is difficult to import detrusion band, because of but desirable.
(3)d/t
If the thickness t attenuation of Copper Foil, even identical surface roughness, the ratio that concave-convex surface occupies copper thickness also becomes greatly, thereby can not fully carry out based on above-mentioned G60
rD/ G60
tDthe evaluation of copper foil surface.Therefore in the present invention,, by being defined as d/t≤0.1, can not carry out the evaluation of copper foil surface according to the thickness of Copper Foil.
At this, d is at three straight line L
1~L
3the suitable each straight line L of depth capacity upper and oil hole
1~L
3the maximum height H of thickness direction
mwith minimum constructive height H
sthe mean value of difference di, straight line L
1~L
3be 175 μ m at copper foil surface place along rolling parallel direction RD length as illustrated in fig. 2, and along more than rolling right angle orientation TD difference interval 50 μ m.Particularly, according to contact roughness, measure L
1~L
3on thickness direction profile and ask maximum height H
mwith minimum constructive height H
s, by each straight line L
1~L
3di on average.
The thickness of Copper Foil (or copper alloy foil) is restriction especially not, but can use aptly for example Copper Foil of 5~50 μ m.
(4)I/I
0
In order to give high bendability to Copper Foil of the present invention, take 200 ℃ of heating 30 minutes and modified under the state of recrystallized structure, the 200 diffracted intensity (I that try to achieve by X-ray diffraction by 200 diffracted intensities (I) of trying to achieve by X-ray diffraction of plane roll with respect to micropowder copper
0) be defined as 20≤I/I
0≤ 40.Thus, the degree of orientation of (200) face becomes appropriate value, obtains the outstanding Copper Foil of balance of bendability and etching.In this case, because the recrystallization set of the crystal orientation with (200) face is organized too inflourishing, therefore (200) organizing in a way of the orientation beyond face disperseed, because this tissue is fallen into and also diminishes by the dish that etching causes partly.In addition, in order to give higher bendability to Copper Foil of the present invention, it is desirable to, take 200 ℃ of heating 30 minutes modified under the state of recrystallized structure, make 25≤I/I
0≤ 40.
If become I/I
0< 20, the degree of orientation of (200) face tails off, and bendability reduces.If become 40 < I/I
0the tissue with the crystal orientation of (200) face increases, it is good that bendability becomes, but (200) the recrystallization set of face is organized too flourishing, thereby the tissue part in orientation beyond (200) face concentrate generation, it is sunken that this tissue becomes large and easy etched and dish occurs, and etching is poor.In addition, in the orientation beyond (200) face and its, etching speed differs widely and also can make etching reduce.
At above-mentioned 200 ℃, the annealing of 30 minutes is to imitate the temperature history of in CCL manufacturing process, Copper Foil being paid.
In addition,, if one or more that Copper Foil are contained select from the group of Ag, Sn, In, Au, Pd and Mg add up to 30~300wtppm, manageable is 20≤I/I
0≤ 40, because of but desirable.
Be 20≤I/I as management
0≤ 40 method, can for example repeat cold rolling and annealing, utilizing final annealing to make average crystallite particle diameter is 10~20 μ m, afterwards in the time that rolling is product thickness of slab, making total degree of finish is 90~96%, suppresses the prosperity of shear band in the mill train before the final mill train of final cold rolling.In this case, in the mill train before the final mill train of final cold rolling, can use the roller of roughness smaller (surface roughness Ra is for for example below 0.05 μ m) to carry out rolling.
(5) gun parallax based on EBSD
As mentioned above, it is a kind of depression that dish falls into, this depression is the heat treatment in the time passing through Copper Foil to engage with resin molding, the ratio of the different crystal grain individualism in the uniform formation of recrystallization of crystal orientation is many, when etching, this independent crystal grain is formed by etching deeper compared with around.Therefore, as above-mentioned heat treatment, imitate the lower heating Copper Foil of the heat-treat condition of the temperature history in CCL manufacturing process, Copper Foil given (at 200 ℃ 30 minutes) and modified be recrystallized structure.And, as the crystal orientation of this state, it is desirable to, the in the situation that of utilizing EBSD to observe copper foil surface after electrolytic polishing, the crystal orientation of plane roll is 30~70% with the area occupation ratio that the differential seat angle in [100] orientation is crystal grain more than 15 degree.
If above-mentioned area occupation ratio is 30~70% in the situation that utilizing EBSD to observe, can obtain all outstanding Copper Foils of bendability and etching.If it is poor that above-mentioned area occupation ratio is less than 30% etching, if exceed 70% bendability reduction sometimes.In addition, be 30~70% in order to make above-mentioned area occupation ratio in the situation that utilizing EBSD to observe, it is desirable to, as described above, in final cold rolling, in mill train before final mill train, suppress the prosperity of shear band, in the mill train before the final mill train of final cold rolling, use the smaller roller of roughness (surface roughness Ra is for for example below 0.05 μ m) to carry out rolling.In addition, if one or more that Copper Foil are contained select from the group of Ag, Sn, In, Au, Pd and Mg add up to 30~300wtppm, be easily 30~70% by above-mentioned area occupation ratio management, because of but desirable.
In addition, to accepting thermal history and becoming the Copper Foil of CCL, also can at 200 ℃, heat 30 minutes.Even if the recrystallization that is organized in of heat treated Copper Foil once further heated also and changes hardly before, thereby in the observation that utilizes EBSD, does not distinguish the Copper Foil of accepting the Copper Foil of thermal history and not accepting, with 200 ℃ of heating 30 minutes.
(6) composition
As Copper Foil, can use more than purity 99.9wt% tough pitch copper (タ Off ピ ッ チ Copper), oxygen-free copper, cathode copper, and it is desirable to contain one or more totals 30~300wtppm selecting from the group of Ag, Sn, In, Au, Pd and Mg.Oxygen-free copper is by JIS-H3510 (alloy numbering C1011) and JIS-H3100 (alloy numbering C1020) regulation, and tough pitch copper is by JIS-H3100 (alloy numbering C1100) regulation.
One example of the manufacture method of rolling Copper Foil of the present invention then, is described.First, after by the hot rolling of ingot bar of the alloying element that comprises copper and necessity and inevitable impurity, repeat cold rolling and annealing, finally utilizing final cold rolling fine finishining is set thickness.
At this, as mentioned above, nearby do not make the surface of Copper Foil too coarse at the final mill train of final cold rolling, in the final mill train of final cold rolling, make the rough surface of Copper Foil, thereby make final copper foil surface coarse, and reduce detrusion band, improve bendability, and dish fall into tail off.And, in the less surface of this kind of detrusion band, G60
rD/ G60
tD< 0.8.
Thereby, at the final mill train of final cold rolling nearby, in order to make copper foil surface too not coarse, smaller roller carries out rolling, or 1 the mill train degree of finish strengthening in final cold rolling carries out rolling to use roughness (surface roughness Ra is for example that 0.5 μ m is following).On the other hand, in the final mill train of final cold rolling, use the larger roller of roughness (surface roughness Ra is for for example more than 0.6 μ m) to carry out rolling, or use the high rolling oil of viscosity to carry out rolling, make the final copper foil surface obtaining coarse.
In addition, in order to make final copper foil surface coarse, and reduce detrusion band, need in final 2 mill traines of final cold rolling or final mill train, use as described above coarse roller or use the high rolling oil of viscosity to carry out rolling, but it is desirable to adjust the rolling condition in final mill train, adjust because be easy to.On the other hand, if started in the past to make the roughness chap of roller, detrusion band prosperity from final 3 mill traines of final cold rolling.
In addition, under capable of regulating annealing conditions so that the average grain diameter of the recrystallization grain that the annealing before utilizing final cold rolling tight obtains becomes 10~20 μ m.In addition, can make the rotary rolling mill degree in final cold rolling is 92~99%.
Embodiment
The element that cathode copper interpolation table 1 is recorded has been cast blank (ingot) in (mist of N2 and CO) (embodiment 4,6,7~14) in (embodiment 1~3,5) and reducing atmosphere respectively in atmosphere.In addition, comparative example 1~5 has been cast blank in argon gas atmosphere.The oxygen that the blank of casting in atmosphere contains 150~300ppm, the blank of casting in reduction atmosphere contains the oxygen with oxygen-free copper (C1020) same degree.The blank of made is carried out to hot rolling until thickness 10mm above at 800 ℃, after surperficial oxidation surface is eliminated, repeat cold rolling and annealing, after the thickness that becomes 0.24mm (embodiment 1~12), 0.12mm (embodiment 13), 0.36mm (embodiment 14), 1.2mm (comparative example 1~5), anneal so that average crystallite particle diameter is 13 μ m respectively afterwards.And utilize final cold rolling fine finishining for thickness 0.012m (embodiment 1~12, comparative example 1~5), 0.006mm (embodiment 13), 0.018mm (embodiment 14).In addition, making the degree of finish of the final cold rolling of embodiment 1~14 is 95%, and the degree of finish that makes the final cold rolling of comparative example 1~5 is 99%.
In addition, final cold rolling carries out 5~15 mill traines, as shown in table 1, changes the surface roughness of roller of final mill train before nearby and the surface roughness of the roller of final mill train and carries out rolling.From the 1st mill train of final mill train till the surface roughness of the roller nearby of final mill train is all identical.
Each Copper Foil test portion to acquisition like this has carried out the evaluation of each characteristic.
(1) glossiness
Measured respectively the glossiness G60 of copper foil surface according to JIS-Z8741 along rolling parallel direction RD and rolling right angle orientation TD
rD, G60
tD.
(2) cube set tissue
After test portion is heated 30 minutes at 200 ℃, ask the integrated value (I) of 200 diffracted intensities of trying to achieve by X-ray diffraction of plane roll.Integrated value (I0) by this value divided by 200 diffracted intensities of trying to achieve by X-ray diffraction of the micropowder copper of measuring in advance (325mesh uses after 1 hour with 300 ℃ of heating in hydrogen stream), has calculated I/I0 value.
(3) (mean value d) for the depth capacity in oil hole
Use contact roughmeter (little slope institute system SE-3400), as shown in Figure 2, ask respectively three straight line L
1~L
3on maximum height H
mwith minimum constructive height H
sdifference di, straight line L
1~L
3be 175 μ m at copper foil surface place along rolling parallel direction length, and along more than rolling right angle orientation TD difference interval 50 μ m.By each straight line L
1~L
3di on average using as d.In addition, adopt d (mm)/t (mm).
(4) gun parallax based on EBSD
After electrolytic polishing, utilize EBSD (backscattering electric wire diffraction instrument, the JXA8500F of Jeol Ltd., accelerating potential 20kV, electric current 2e-8A, measurement range 1000 μ m × 1000 μ m, walk wide 5 μ and m) have observed in (2) and heated 30 minutes test portion surfaces afterwards with 200 ℃.Asking with the differential seat angle in [100] orientation by image analysis is the area occupation ratio of crystal grains more than 15 degree.And, by the visual number that exceedes 20 μ m at the range of observation intercrystalline particle diameter of test portion surface 1mm pros of having calculated.
(5) etching
Evaluate as follows etching.First, use etching solution (being respectively ADEKA TEC (ア デ カ テ ッ Network) CL-8 (Asahi Denka Co., Ltd. (ア デ カ) system) liquid and DP-200 (weak Yuan ユ ー ジ ラ イ ト system) liquid) to carry out at normal temperatures etching 2 minutes, by the image light and shade binaryzation of the surface photography of the range of observation of the 1mm pros after utilizing light microscope to etching, calculate the ratio of light and shade.The tissue with [100] orientation is owing to being the face parallel with copper foil surface, thus brighter, under other orientation, tiny concavo-convex owing to producing on surface, therefore that diffuse reflection causes seeming is darker.
Then, state clearly among portion and dark portion upper, ratio is less than to the tissue that a side of 50% regards the side that area occupation ratio is few as.Because the few side's of area occupation ratio tissue is surrounded and exists by the many sides' of area occupation ratio tissue, therefore utilize the side's that polygonal approximation area occupation ratio is few tissue, the minimum diameter that has calculated this polygonal circumscribed circle exceedes the number at the position of 50 μ m.No matter use any liquid of ADEKA TEC CL-8, DP-200, in range of observation, this position is all below 10, and the test portion by the difference of the etch quantity after 30 minutes after the etch quantity before 30 minutes and final cold rolling after final cold rolling and with 200 ℃ of heating and with 200 ℃ of heating in ± 10% is decided to be etching good (zero), by above-mentioned number, more than 10, or exceed ± 10% test portion of the difference of above-mentioned etch quantity is decided to be etching poor (×).
At this, utilize (the Copper Foil weight after the Copper Foil weight-etching before etching) to calculate etch quantity, if, in ± 10%, thinking, the difference of above-mentioned etch quantity has or not recrystallization after final cold rolling, and etch quantity is all difficult to change, and etching is outstanding.
In addition,, at copper foil surface, compared with bright and dark face mix, any one the many situation in bright or dark face has the good tendency of etching.
(6) scar on surface
, there is 5 places/m by the scar in rolling direction with length more than 10mm in the surface of visual each test portion
2above situation is decided to be ×.
(7) bendability
After test portion being heated 30 minutes with 200 ℃ and makes its recrystallization, to polyimide film (trade name: Kapton(カ プ ト Application) (registration mark) EN) one side (face bonding with Copper Foil) coating 2 μ m thermoplasticity PI bonding agents after dry, formed the thick resin bed of 27 μ m.Copper Foil is laminated in to the binding agent face of this resin bed and carries out Vacuum Heat punching press, made copper-clad laminated body.Utilize the bend test device shown in Fig. 3 to carry out the mensuration of the flexible life of copper-clad laminated body.This device is the structure that vibration transmission member 3 is incorporated into vibration driving body 4, by test Copper Foil 1 the top ends of the part of the screw 2 with shown in arrow and 3 altogether 4 locate to be fixed on device.If vibration section 3 drives up and down, the pars intermedia of Copper Foil 1 is bent into hairpin shape with set radius of curvature r.In this test, the number of times before the fracture while asking under following condition repeated flex.
In addition, experimental condition is as follows: test film width: 12.7mm, test film length: 200mm, test film extracts direction: extract in the mode that the length direction of test film is parallel with rolling direction, radius of curvature r:2.5mm, vibratility adjustment: 25mm, vibration velocity: 1500 beats/min.In addition, be more than 500,000 times in the situation that in flexible life, be judged as and there is outstanding bendability.If flexible life is more than 500,000 times, there is the good bendability of the harsh bending that can tolerate folding movable part of fold type portable telephone etc.
By the table 1 that the results are shown in obtaining.
[table 1]
As shown in Table 1, at G60
rDbe more than 100 and 300 following and 20≤I/I
0≤ 40, and d/t is below 0.1, G60
rD/ G60
tDbe less than in 0.8 the situation of each example, etching is outstanding, and copper foil surface do not have scar, and bendability is also good.
On the other hand, be in final cold rolling, make final mill train nearby before the surface roughness of roller and the surface roughness of the roller of final mill train be in the situation of the comparative example 1 below Ra=0.05 μ m, the G60 of copper foil surface
rDexceed 300, produce scar at copper foil surface, treatability is poor.
Be in final cold rolling, make final mill train nearby before the surface roughness of roller coarse to more than Ra=0.06 μ m, the surface roughness that makes the roller of final mill train is in the situation of the comparative example 2 below Ra=0.05 μ m, is I/I
0> 40, the sunken number of dish increases therefore etching reduces, in addition, the G60 of copper foil surface
rDexceed 300, produce scar at copper foil surface, treatability is poor.
Be in final cold rolling, make final mill train nearby before the surface roughness of roller and the surface roughness of the roller of final mill train all coarse in the situation of comparative example 3,4,5 more than Ra=0.6 μ m, be I/I
0> 40, the sunken number of dish increases therefore etching reduces.
In addition, the in the situation that of comparative example 3,4, owing to making, the roll surface roughness of whole mill traines of final cold rolling is coarse, thus at material internal, the prosperity of detrusion band, the degree of orientation of the crystallization of copper foil surface reduces, and becomes I/I
0> 40.
On the other hand, the in the situation that of comparative example 5, due to make final mill train nearby before the roughness ratio comparative example 3,4 of roller level and smooth, therefore glossiness becomes the value higher than comparative example 3,4, but the inhibition of shear band is still insufficient, is I/I
0> 40, the sunken number of dish increases therefore etching reduces.In addition, in the case of make final mill train nearby before roller roughness be to suppress shear band 0.07 μ m, have the plate speed etc. of reduction method, but think that glossiness exceedes 300 in this case, injurious surface mark is judged to be ×.