阅读说明：本技术 柔韧印刷基板用铜箔、使用了该铜箔的覆铜层叠体、柔韧印刷基板和电子设备 (Flexible printed base plate copper foil, the copper clad layers stack for having used the copper foil, flexible printed base plate and electronic equipment ) 是由 坂东慎介 于 2019-05-15 设计创作，主要内容包括：本发明提供：提高了蚀刻速度的柔韧印刷基板用铜箔、使用了该铜箔的覆铜层叠体、柔韧印刷基板和电子设备。一种柔韧印刷基板用铜箔,该铜箔是含有99.9质量%以上的Cu和作为添加元素的0.0005～0.0300质量%的P、0.0005～0.2500质量%的Mg的任一者或两者、且余量由不可避免的杂质构成的轧制铜箔,电导率为80%以上,并且在25<I>μ</I>m×25<I>μ</I>m的视野下观察铜箔表面时晶界的总长度为600<I>μ</I>m以上。(The present invention provides: improving the flexible printed base plate copper foil of etching speed, the copper clad layers stack for having used the copper foil, flexible printed base plate and electronic equipment.A kind of flexible printed base plate copper foil, the copper foil is the rolled copper foil that either or both of the Mg of the P of the Cu containing 99.9 mass % or more and 0.0005~0.0300 mass % as addition element, 0.0005~0.2500 mass % and surplus are made of inevitable impurity, conductivity is 80% or more, and 25 μ m×25 μ The total length of crystal boundary is 600 when observing copper foil surface under the visual field of m μ M or more.)

1. flexible printed base plate copper foil, which is the Cu containing 99.9 mass % or more and as the 0.0005 of addition element Either or both and the surplus of the Mg of the P of~0.0300 mass %, 0.0005~0.2500 mass % are by inevitable impurity The rolled copper foil of composition,

Conductivity is 80% or more, and

25μm×25μWhen observing copper foil surface under the visual field of m, the total length of crystal boundary is 600μM or more.

2. flexible printed base plate copper foil described in claim 1, wherein with 100~300 DEG C/min of heating rate 300 When carrying out heat treatment in 30 minutes at DEG C, above-mentioned conductivity is 80% or more, and

The total length of above-mentioned crystal boundary is 600μM or more.

3. flexible printed base plate copper foil of any of claims 1 or 2, which includes that JIS-H3100 (C1100) is standardized The oxygen-free copper of tough pitch copper or JIS-H3100 (C1020).

4. copper clad layers stack, which is by flexible printed base plate copper foil according to any one of claims 1 to 3 It is constituted with resin layer stackup.

5. flexible printed base plate, which is the shape on the above-mentioned copper foil of copper clad layers stack as claimed in claim 4 It is constituted at circuit.

6. electronic equipment, which has used flexible printed base plate described in claim 5.

Technical field

The present invention relates to the copper foil for the wiring part for being suitable for flexible printed base plate etc., the copper-clad laminated of the copper foil is used Body, flexible wiring plate and electronic equipment.

Background technique

With the small-sized, slim of electronic equipment, high performance, it is desirable that with high-density installation flexible printed base plate (flexible cloth Line plate, hereinafter referred to as " FPC ").

FPC refers to (Copper Clad Laminate, following by the copper clad layers stack that obtains copper foil and laminated resin Referred to as CCL) etching and formed wiring, again be referred to as coating resin layer cladding thereon obtained from substrate.

However, needing to miniaturize wiring by the etching of copper foil, making to resist in order to high-density installation FPC Lose agent pattern width and resist narrower intervals.However, due to copper foil etching speed can with the reduction at resist interval and It declines to a great extent, therefore etching needs for a long time, yield decline.Moreover, side etching opposite can become if the time of etching is long Greatly, narrow with the bottom width top in comparison width of circuit, the shape deterioration of circuit, therefore, it is difficult to carry out high-precision etching, The miniaturization of circuit is limited.

Therefore, someone develops following methods: on the surface of copper foil, setting etching speed is slow compared with copper foil and is able to use The envelope that etching solution identical with copper foil is etched, to accurately be etched processing (patent document to fine wiring 1)。

Summary of the invention

Problems to be solved by the invention

However, still resting in the case where technology described in Patent Document 1 and inhibiting the slow adjoint side of the etching speed of copper foil Facet etch, the etching speed itself without being to speed up copper foil, therefore there is yield difference.

The present invention be it is completed to solve the above problems, its purpose is to provide: improve the flexible of etching speed Printed base plate copper foil, the copper clad layers stack for having used the copper foil, flexible printed base plate and electronic equipment.

Means for solving the problems

Present inventor has performed various researchs, as a result, it has been found that: by the total length of the crystal boundary extended in copper foil tissue, etching is anti- Answer speed that can become larger, etching speed improves.

That is, it is the Cu containing 99.9 mass % or more and as addition element that flexible printed base plate of the invention, which uses copper foil, Either or both and can not keep away by surplus of the Mg of the P of 0.0005~0.0300 mass %, 0.0005~0.2500 mass % The rolled copper foil that the impurity exempted from is constituted, conductivity are 80% or more, and 25μm×25μCopper foil surface is observed under the visual field of m When, the total length of crystal boundary is 600μM or more.

In addition, flexible printed base plate copper foil of the invention with 100~300 DEG C/min of heating rate at 300 DEG C When carrying out heat treatment in 30 minutes, above-mentioned conductivity can be 80% or more, and the total length of above-mentioned crystal boundary can be 600μm More than.

The tough pitch copper or JIS-H3100 that flexible printed base plate copper foil of the invention can be standardized by JIS-H3100 (C1100) (C1020) oxygen-free copper is formed.

Copper clad layers stack of the invention is to form above-mentioned flexible printed base plate copper foil and resin layer stackup.

Flexible printed base plate of the invention is to form circuit on the above-mentioned copper foil of above-mentioned copper clad layers stack and constitute.

Electronic equipment of the invention is formed using above-mentioned flexible printed base plate.

Invention effect

According to the present invention, it can obtain improving the flexible printed base plate copper foil of etching speed.

Brief description

Fig. 1 is the figure for showing the relationship between etching period and the total length of crystal boundary.

Fig. 2 is the figure for showing the heating curves (Heat pattern) of final full annealed.

Specific embodiment

Hereinafter, being illustrated to the embodiment of copper foil according to the present invention.It should be noted that in the present invention, Unless otherwise specified, then " % " expression " quality % ".

< forms >

Copper foil according to the present invention contains the Cu of 99.9 mass % or more and 0.0005~0.0300 matter as addition element Either or both of the P of %, the Mg of 0.0005~0.2500 mass % are measured, and surplus is made of inevitable impurity.Cu is excellent It is selected as 99.96 mass % or more.

If contain P, Mg either or both as addition element, by by (system when rolled copper foil and laminated resin When making CCL) heat treatment, the aggregate values (total length) of aftermentioned crystal boundary length can be extended.This is because: if containing in copper foil P, either or both of Mg is then easy answering for driving force of the accumulation as recrystallization karyogenesis when by above-mentioned heat treatment Become.

If the content of P is difficult to extend the total length of crystal boundary less than 0.0005 mass % (5 mass ppm).If the content of P is super 0.0300 mass % (300 mass ppm) is crossed, then conductivity declines, and is not suitable for flexible printed base plate.

If the content of Mg is difficult to extend the total length of crystal boundary less than 0.0005 mass % (5 mass ppm).If the content of Mg More than 0.2500 mass % (2500 mass ppm), then conductivity declines, and is not suitable for flexible printed base plate.

Copper foil according to the present invention can be formed in comprising JIS-H3100 (C1100) tough pitch copper (TPC) standardized or P containing 0.0005~0.0300 mass % as addition element in the composition of the oxygen-free copper (OFC) of JIS-H3100 (C1020) Composition.

The total length > of < crystal boundary

25μm×25μWhen observing copper foil surface under the visual field of m, the total length of crystal boundary is 600μM or more.

The etching speed of copper foil is improved because increasing etching reaction speed, is easy the preferential intergranular (grain that etching reaction occurs Boundary) it is more, then etching reaction speed more improves.

As evaluate the intergranular number method, the length being connected to each other as crystal grain i.e. crystal boundary is provided according to gun parallax Total length.

If the total length of crystal boundary is less than 600μM, then the crystal boundary for being easy preferential generation etching reaction is few, so etching speed is not It can sufficiently improve.It should be noted that the total length of crystal boundary is longer, then the crystal boundary for being easy preferential generation etching reaction is more, Fine path can be rapidly and accurately formed, therefore the upper limit is not limited, but practical upper for example, 3000μm。

The measuring method of crystal boundary total length is that by EBSD, (electronics is carried on the back after the surface of copper foil sample to be carried out to electrolytic polishing Scattering and diffracting: electron backscatter diffraction) it is quantified.Specifically, EBSD measurement is to make With EBSD (OIM (orientation mapping microtechnic, the Orientation Imaging that TSL Solutions company manufactures Microscopy)) device calculates the total length of crystal boundary using incidental analysis software (OIM analysis5) of device.It carries out When data are analyzed, CI value (confidence index, Confidential Index) is for 0.05 data below from analysis due to precision is low Middle removing, crystal boundary condition are 5 ° or more.

In addition, EBSD determination condition is as follows: measurement voltage is 15kV, operating distance 18mm, sample tilt angle are 70 °, measurement spacing be d=0.2μm。

< is heat-treated 30 minutes > at 300 DEG C

Copper foil according to the present invention is used for flexible printed base plate, at this point, copper foil and laminated resin and the CCL that is formed can be The heat treatment for making resin solidification is carried out at 200~400 DEG C, so should become as caused by rolling processing by the heat treatment To release, recrystallize.

Therefore, flexible printed base plate according to the present invention with copper foil define with formed after laminated resin it is copper-clad laminated The copper foil of the state for solidifying heat treatment after body, receiving resin.That is, indicating not carry out after having received heat treatment The copper foil (total length of crystal boundary) of the state of new heat treatment.

On the other hand, flexible printed base plate according to the present invention with copper foil define to the copper foil before laminated resin into State when the above-mentioned heat treatment of row.This be heat-treated at 300 DEG C 30 minutes be to have imitated to consolidate resin in the stacking of CCL Change the temperature condition of heat treatment.By carrying out above-mentioned heat treatment to the copper foil before laminated resin, it is possible to determine that whether the copper foil In the range of the present application.

It should be noted that the oxidation of the copper foil surface caused by being heat-treated in order to prevent, the environment of heat treatment is preferably also Originality or non-oxidizing environment, as long as such as vacuum environment or argon, nitrogen, hydrogen, carbon monoxide etc. or by these mixing The environment etc. that gas is constituted.As long as heating rate is between 100~300 DEG C/min.

Copper foil of the invention can for example be operated as follows and be manufactured.It melted, cast firstly, adding P in copper ingot, Hot rolling, cold rolling and annealing are carried out later, it is possible thereby to manufacturing copper foil.

Here, temperature and arrival time, (2) final cold rolling are reached by the material of the final full annealed of control (1) Degree of finish η, it can be ensured that control the total length of crystal boundary 600μM or more.

Material by controlling final full annealed reaches temperature and arrival time, can make the conduct when manufacturing CCL The strain of driving force when generating recrystallization core sufficiently remains in final full annealed, can extend the total length of crystal boundary.

The material of final full annealed reaches temperature and arrival time to be changed also according to the manufacturing condition of copper foil, is not had Limit, such as shown in Fig. 2, can set as follows: the first material reaches temperature and recrystallizes as T1=350~450 DEG C, from final Annealing starts (room temperature) and carries out cooling (placement cooling), the second material for ta=3 hour or less, since T1 to the arrival time of T1 Expect that up to temperature be T2=250~350 DEG C.

Here, due to T1 >=T2, so generating multiple recrystallization cores at T1, only use is answered in recrystallization at T2 Become, will not cause to recrystallize grain growth (recrystallizing grain growth at T2 without using strain)).

In addition, the ta the short, the recrystallization core generated is more, thus preferably, if but the time it is too short, according to the portion of material Position, temperature can become unevenly, as long as therefore being set as uniform range (such as 1 hour or more).

If the time of Ta becomes too long, karyogenesis preferentially occurs for the crystal grain in the orientation recrystallized earlier compared with other orientation, Later, grain growth is occurred as driving force using the strain differential of recrystallization grain and other processing grains that karyogenesis preferentially has occurred, There is no residual strain.

Material is reached temperature and indicates to be measured outside coil using thermocouple of the configuration on final full annealed device Side to multiple positions between inside material surface temperature when reach target temperature or more position actual material surface The simple average value of temperature.Here, as long as target temperature is respectively set as temperature identical with T1, T2.

Arrival time, ta was shorter, and the recrystallization core of generation is more, and recrystallization grain can become fine, therefore preferably.If arriving It is more than 3 hours up to time ta, then recrystallizes partial size and become thick, is unable to fully accumulation strain sometimes in rolling later.

If the insufficient above-mentioned lower limit value of T1, T2, can not be recrystallized, and coarse cast sturcture is remained, later It is unable to fully accumulation strain in rolling, therefore recrystallizes the generation reduction of core when manufacturing CCL, the total length of crystal boundary contracts sometimes It is short.

If T1, T2 are more than above-mentioned upper limit value, recrystallize partial size and become thick, be unable to fully accumulate in rolling later Strain, is difficult to extend the total length of crystal boundary sometimes.

Similarly, by controlling the degree of finish η of final cold rolling, when can make when manufacturing CCL as recrystallization karyogenesis The strain of driving force sufficiently remained in final full annealed, the total length of crystal boundary can be extended.

The degree of finish η of final cold rolling also according to copper foil manufacturing condition and change, do not limit, such as η can be set as More than 5.82.

Using the material thickness faced before cold rolling before final annealing as A0, with the material after the just cold rolling before final annealing Thickness as A1, degree of finish η is indicated with η=ln (A0/A1).

If the degree of finish η of final cold rolling is too low, it is difficult to sufficiently import to be used as when manufacturing CCL in final cold rolling to tie again The strain of driving force when nucleus generates.The upper limit of degree of finish η is not particularly limited, and practical is above 7.45 or so.

< copper clad layers stack and flexible printed base plate >

In addition, being carried out to copper foil of the invention: (1) resin precursor (such as the polyimide precursor for being known as varnish) being cast and added Heat be allowed to polymerize and (2) using with Ranvier's membrane thermoplastic adhesive of the same race on copper foil of the invention laminated Ranvier's membrane, by This available copper clad layers stack (CCL) being made of this 2 layers of copper foil and resin base material.In addition, by copper foil of the invention The laminated Ranvier's membrane for being coated with bonding agent can be obtained by copper foil, resin base material and adhesive layer this 3 layers of copper clad layers constituted between it Stack (CCL).When manufacturing these CCL, heat treatment is carried out to copper foil and is allowed to recrystallize.

Circuit is formed on them using photoetching technique, as needed circuit is implemented to be electroplated, then laminated cover film, by Flexible printed base plate (flexible wiring plate) can be obtained in this.

Therefore, copper clad layers stack of the invention is to form copper foil and resin layer stackup.In addition, of the invention is flexible Printed base plate is to form circuit on the copper foil of copper clad layers stack and constitute.

As resin layer, can enumerate: (liquid crystal is poly- by PET (polyethylene terephthalate), PI (polyimides), LCP Close object), PEN (polyethylene naphthalate), but it is not limited to this.In addition, their resin can be used as resin layer Film.

As the laminating method of resin layer and copper foil, can be coated with to form material and the progress of resin layer on the surface of copper foil Heating film forming.In addition, it is possible to use resin film uses bonding agent below as resin layer between resin film and copper foil, Resin film hot pressing can also be connected on copper foil without using bonding agent.Wherein, never apply the angle of extra heat to resin film Degree considers, it is preferable to use bonding agent.

In the case where using film as resin layer, which can be laminated on copper foil via adhesive layer.Such case Descend the bonding agent, it is preferable to use with film identical component.For example, in the case where using polyimide film as resin layer, bonding Oxidant layer is it is also preferred that use polyimides system bonding agent.Still it should be noted that, polyimide adhesive mentioned here, which refers to, includes The bonding agent of imide bond further includes polyetherimide etc..

It should be noted that present invention is not limited to the embodiments described above.As long as in addition, playing effect effect of the invention Fruit, then the copper alloy in above embodiment can also contain other compositions.

For example, can be implemented to the surface of copper foil at the surface of roughening treatment, antirust treatment, resistance to heat treatment or their combinations Reason.

[embodiment 1]

Next, enumerating embodiment to illustrate the present invention in further detail, however, the present invention is not limited to these examples.In electricity It solves and adds P in copper to form forming for table 1, cast in Ar environment, obtained ingot bar.Oxygen content in ingot bar is insufficient 15ppm.The ingot bar is subjected to hot rolling at 900 DEG C after homo genizing annelaing, later with degree of finish η=1.26 carry out cold rolling, be set as T1= 450 DEG C, ta=2 hour, T2=350 DEG C, carry out final full annealed.

Later, the oxide skin that surface generates is removed, final cold rolling is carried out with degree of finish η shown in table 1, obtains target most The copper foil of whole thickness.With 150 DEG C/min of the heating rate heat to the implementation 300 DEG C × 30 minutes of resulting copper foil under Ar environment Processing, has obtained copper foil sample.Copper foil after heat treatment has imitated the state that heat treatment is received in the stacking of CCL.

The evaluation > of < copper foil sample

1. conductivity

25 DEG C of conductivity is determined by 4 terminal methods according to JIS H 0505 for each copper foil sample after above-mentioned heat treatment (%IACS)。

If conductivity is greater than 80%IACS, electric conductivity is good.

2. the total length of crystal boundary

For each copper foil sample after above-mentioned heat treatment, as above operates, measure the total length of crystal boundary.

3. etching period

Each copper foil sample that size after above-mentioned heat treatment is 100mm × 100mm is immersed in the Tech of Kaneka company manufacture In CL-8 (the 20vol% aqueous solution of hydrogen peroxide system), measurement is until copper foil is completely etched the time of (copper foil melts completely).

4. fine circuits formative (yield)

In above-mentioned evaluation 3, the sample by etching period less than 500 seconds is evaluated as zero, and (fine circuits formative (yield) is good It is good), 500 seconds or more samples are evaluated as × (fine circuits formative (yield) is poor).

Acquired results are shown in Table 1.

[table 1]

As shown in Table 1: being 600 in the total length of P, Mg containing specified amount, crystal boundaryμIn the case where each embodiment of m or more, erosion Quarter, speed was fast, and fine circuits formative (yield) is excellent.

It should be noted that as shown in Figure 1, it is seen that substantial linear is related between etching period and the total length of crystal boundary.

On the other hand, in the case where T1 is more than 450 DEG C of comparative example 1, the total length of crystal boundary is less than 600μM, etching speed Degree decline, fine circuits formative (yield) are poor.It is thought that due to: T1 is excessively high, leads to the strain imported in copper foil manufacture It disappears in final full annealed, is unable to fully generate recrystallization core by the heat treatment of imitation CCL manufacture later.

In the case where T1 is more than 350 DEG C of comparative example 2, the total length of crystal boundary is less than 600μM, etching speed decline are micro- Thin circuit formative (yield) is poor.It is thought that due to: T2 is excessively high, and the strain imported in copper foil manufacture is caused finally to tie again It disappears in crystalline substance annealing, is unable to fully generate recrystallization core by the heat treatment of imitation CCL manufacture later.

In the case where comparative example 4 less than 250 DEG C of comparative example 3 of the T1 less than 350 DEG C and T2, there is no recrystallizations. The copper foil not recrystallized lacks bendability, therefore is natively not suitable as flexible printed base plate.

In the case where the degree of finish η of final cold rolling is lower than comparative example 5 of each embodiment, the total length of crystal boundary is less than 600μ M, etching speed decline, fine circuits formative (yield) are poor.It is thought that due to: the degree of finish η of final cold rolling is too low, causes Without strain is sufficiently imported in normal direction copper foil in final cold rolling, it is unable to fully give birth to by the heat treatment of imitation CCL manufacture later At recrystallization core.

In the case where comparative example 6 less than 0.0005 mass % of P content in copper foil, the total length of crystal boundary is less than 600μ M, etching speed decline, fine circuits formative (yield) are poor.It is thought that due to: the P in copper foil is few, so in manufacturing copper foil When be unable to fully import strain, be unable to fully generate by the heat treatment of imitations CCL later manufacture and recrystallize core.

In the case that P content in copper foil is more than 0.0300 comparative example 7, conductivity is less than 80%, poorly conductive.

In the case where comparative example 8 less than 0.0005 mass % of Mg content in copper foil, the total length of crystal boundary is also insufficient 600μM, etching speed decline, fine circuits formative (yield) are poor.It is thought that due to: the P in copper foil is few, so manufacturing It is unable to fully import strain when copper foil, is unable to fully generate recrystallization core by the heat treatment of imitation CCL manufacture later.

In the case that Mg content in copper foil is more than 0.2500 comparative example 9, conductivity is less than 80%, poorly conductive.