JP5255496B2 - Metal-clad laminate and method for producing metal-clad laminate - Google Patents

Description

  The present invention relates to a metal-clad laminate and a method for producing a metal-clad laminate.

  Flexible circuit boards using liquid crystal polymer films, polyimide films, and the like, which are metal-coated polymer films (metal-coated polymer films), are used as wiring boards for mobile phones, liquid crystal televisions, and the like.

  For example, film metal-clad laminates in which a metal layer (underlying metal layer / upper metal conductive layer) is formed on a polyimide resin film having excellent heat resistance have been used for flexible circuit boards. Here, the metal of the base metal layer is nickel (Ni) or the like, and the metal of the upper metal conductive layer is copper (Cu) or the like. However, since this film has a high water absorption, there is a problem that the dimensional accuracy is lowered in a humid atmosphere, or the absorbed moisture creates a gap at the interface between the metal and the resin, resulting in poor adhesion. Therefore, attention has been paid to a liquid crystal polyester film having excellent heat resistance and low water absorption as an alternative to this polyimide resin film.

  Furthermore, from the viewpoint of cost, a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, or a polyether ether ketone (PEEK: registered trademark) film is used as a polymer film.

  In addition, since the wiring using the flexible circuit board is used in a place where the wiring is bent or attached to the device or repeatedly bent, the film metal-clad laminate used for the flexible circuit board is excellent in flexibility. (To withstand repeated bending) is required.

  As a method for producing the film metal-clad laminate, conventionally, a method of attaching a metal foil on a polyimide resin film with an adhesive or thermocompression bonding of a metal foil on a thermoplastic resin film has been used (Patent Document 1). reference). Here, the metal of the metal foil is Cu or the like. While the copper foil used for the flexible circuit board exhibits good flexibility, the thickness of the copper foil is generally the thinnest about 9 μm (refer to Patent Document 2), and space saving of recent flexible boards has been achieved. -It is difficult to cope with the reduction in thickness and weight per substrate accompanying the increase in the number of processing information from the direction of increasing the number of processing information.

  On the other hand, as a manufacturing method for forming a thin metal layer on an insulator such as a resin film, there is a method of forming a thin film metal layer by vapor deposition / sputtering or electroless plating (see Patent Documents 3 to 4). Vapor deposition / sputtering and electroless plating have the advantage that a thin metal layer can be formed.

JP 2008-094431 A JP 2006-261650 A JP 2007-317782 A JP 2008-110602 A

  However, in the metal-clad laminate in which a thin metal layer is formed on an insulator described in Patent Document 3, when a metal layer is further formed on the surface of the thin metal layer (for example, a thin base metal layer is formed) In addition, when a metal layer is formed by electrolytic plating or the like, if the current is excessively applied, the base film will generate excessive heat, so that the applied current density is limited. On the other hand, when the current density is reduced, the crystal grain size of the formed metal layer is small, and the finished metal-clad laminate has a problem that the flexibility is not good. Patent Document 4 describes a method for suppressing warpage of a metal-clad laminate by heat-treating a metal-clad laminate in which a thin metal layer is formed on an insulator. There is no direct description of improvement.

  Accordingly, an object of the present invention is to provide a metal-clad laminate having good flexibility and a method for producing the metal-clad laminate.

The inventor has conducted extensive research on the above-described conventional problems, and as a result, has decided to solve the problem by the following means. That is,
(1) Polyester film, thermoplastic liquid crystal polymer film, or polyether agent
A flexible metal-clad laminate in which a base metal layer is formed on at least part of the surface of a thermoplastic film as a base material selected from a terketone polymer film , and a copper layer is formed thereon. , The average crystal grain size of the copper layer increases from the substrate side toward the thickness direction,
Ri average range der least 5μm below 2μm grain size of the copper layer, the average carbon of the copper layer
A metal-clad laminate having a concentration in the range of 3 ppm to 15 ppm ,
(2) In the above (1), the base metal layer is a layer made of a Ni-P alloy.
The metal-clad laminate as described ,
(3) The surface of the thermoplastic film has a surface roughness Rz of 1.0 to 1.5.
The metal-clad laminate as described in (1) or (2) above ,
(4) The copper layer is composed of at least two layers, and the average crystal grain size of the copper layer is in order from the base material side.
Any one of said (1) thru | or said (3) characterized by becoming larger next.
Metal clad laminate ,
(5) The base metal layer and the copper layer are provided on both surfaces of the thermoplastic film.
The metal-clad laminate according to any one of (1) to (4) above ,
(6) The electronic device according to any one of (1) to (5), which is used as an electronic component application.
Metal clad laminate,
(7) Polyester film, thermoplastic liquid crystal polymer film, or polyether agent
On at least part of the surface of a thermoplastic film selected from terketone polymer films
A method for producing a flexible metal-clad laminate in which a base metal layer is formed and a copper layer is formed thereon.
The thermoplastic film is immersed in an alkaline solution, and the surface of the thermoplastic film is
A surface roughness Rz of 1.0 to 1.5 is formed on the surface, and the surface of the thermoplastic film is formed on the surface.
In forming a base metal layer and forming the copper layer on the base metal layer by electrolytic plating,
The plating layer is composed so that the average carbon concentration in the copper layer is 15 ppm or less, and the copper layer
The current density when forming the film is 0.5 to 10 A / dm ² , and the current density is from the base material side.
By increasing toward the surface direction, the average crystal grain size of the copper layer increases in the thickness direction from the substrate side.
The average crystal grain size range of the copper layer is 2 μm or more and 5 μm or less, and
Gold having an average carbon concentration in the copper layer in the range of 3 ppm to 15 ppm
A method for producing a metal laminate ,
(8) After the formation of the copper layer, heat treatment at 150 ° C. to 200 ° C. is further performed in an inert atmosphere.
The method for producing a metal-clad laminate as described in (7) above is provided.

  According to the present invention, for a metal-clad laminate in which a metal layer is formed on at least a part of the surface of a flexible thermoplastic base film, the metal layer is formed on the base film on which the base metal layer is formed. In this case, by controlling the average crystal grain size of the metal layer and the amount of carbon in the metal film, a metal-clad laminate having good flexibility can be provided.

It is explanatory drawing which shows the cross section of one embodiment of the metal-clad laminated body of this invention, (a) is a case where a metal layer (copper layer) is one layer, (b) is a metal layer (copper layer) having multiple layers. Each case is shown.

  An embodiment of the present invention will be described with reference to the drawings. In addition, the embodiment described below is for explanation, and does not limit the scope of the present invention. Accordingly, those skilled in the art can employ embodiments in which each or all of these elements are replaced by equivalents thereof, and these embodiments are also included in the scope of the present invention.

  FIG. 1 is an explanatory view showing a cross section of one embodiment of a metal-clad laminate of the present invention, where (a) is a single metal layer (copper layer), and (b) is a metal layer (copper layer). Shows the case of multiple layers.

  In FIG. 1, 1 is a base material such as a polymer film, 2 is a base metal layer, and 3 is a metal layer (copper layer). FIG. 1A shows an example in which the metal layer (copper layer) is one layer, and FIG. 1B shows an example in which the metal layer (copper layer) has a plurality of layers (here, three layers).

  In FIG. 1, a circle indicated by a dotted line in the copper layer 3 is a circle indicating an average crystal grain size, and actually each crystal grain is adjacently formed in a layered form with almost no gap. .

  In the method for producing a metal-clad laminate to which the present invention is applicable, first, a base metal layer is formed on at least a part of the surface of a flexible thermoplastic polymer film. Then, a copper layer is formed on the formed base metal layer by electrolytic plating.

The current density when forming the copper layer by electrolytic plating after forming the base metal layer on at least a part of the surface of the flexible thermoplastic polymer film described above is 0.5 to 10 A / dm ² , more preferably 1 to 7 A / dm ² is desirable. When the current density is 0.5 A / dm ² or less, the interlayer adhesion between the base metal layer and the copper layer is not sufficient, which causes a defect such as peeling. Further, when the current density is 10 A / dm ² or more, the temperature of the metal-clad laminate rises due to electrical heat generation during electroplating, and the flexible thermoplastic polymer film as a base material is deformed and deformed. It becomes a cause of defects such as burning.

  As a forming method for forming a copper layer by electrolytic plating after forming a base metal layer on at least a part of the surface of the above-described flexible thermoplastic polymer film, a uniform current density is formed at a time. It may be formed up to a target metal thickness, or a method of forming a metal layer stepwise with different current densities by changing the current density may be used. The number of formations of the copper layer may be one time or a total of a plurality of times.

  As a plating bath composition for forming a copper layer by electrolytic plating after forming a base metal layer on at least a part of the surface of the above-described flexible thermoplastic polymer film, carbon in the copper layer is used. It is desirable to compose the plating bath so that the amount is 15 ppm or less. When the amount of carbon is 15 ppm or more, the crystal grain size becomes small, and the flexibility of the produced metal-clad laminate is reduced. Moreover, when the amount of carbon becomes very low, the surface roughness of the produced metal-clad laminate becomes rough, and it becomes unsuitable for use in FPC.

If the average crystal grain size of the copper layer on the base material side is fine as a cause of the deterioration of the flexibility of the metal-clad laminate, cracks are likely to occur from the joint portion when bent, resulting in poor conduction. This leads to poor flexibility.
The average crystal grain size of the copper layer when the copper layer is formed by electrolytic plating after forming the base metal layer on at least part of the surface of the flexible thermoplastic polymer film described above is It is desirable to be 2 μm or more and 5 μm or less. When the average crystal grain size is smaller than 2 μm, the produced metal-clad laminate does not exhibit good flexibility. On the other hand, if the average crystal grain size is larger than 5 μm, the surface roughness of the produced metal-clad laminate is rough and it is not suitable for use in FPC.

  In addition, the average crystal grain diameter as used in the field of this invention first takes the photograph of the surface in which the crystal grain is formed with a transmission microscope. Then, the area of the crystal grains in the photograph is actually measured at 10 points or more, the diameter when a perfect circle having the area is calculated is calculated, and the calculated value is set as the average particle diameter.

  The crystal structure of the copper layer is a plating of a granular crystal structure. Depending on the plating composition, there may be a columnar crystal structure, but in that case, when bending stress is applied to the finished metal film, there is a high probability that cracks will occur along the columnar crystal grain boundaries and breakage tends to occur. It is.

  However, even when a metal layer having a columnar crystal structure is formed, a granular crystal structure may be obtained by recrystallizing the metal layer. In such a case, a metal layer having a columnar crystal structure is first applied and then recrystallized to form a granular crystal structure.

  In addition, the thickness of the metal layer of the metal-clad laminate is set to 0.1 μm to 20 μm. This is because when the thickness of the metal layer becomes thinner than 0.1 μm, the electric resistance value becomes higher than the practical level or beyond, and cannot be used practically. In addition, when the thickness of the metal layer is greater than 20 μm, it is difficult to suppress the warp of the metal-clad laminate, and the flatness becomes stricter than the practical range.

  Accordingly, the thickness of the metal layer is preferably 0.1 μm to 20 μm in the case of a single metal layer, and is preferably 0.1 μm to 20 μm as the total metal layer thickness when a plurality of metal layers are combined. .

Further, as a polymer film having flexibility described above, poly ethylene terephthalate (P
ET), can be a polyester film or the like is applied, such as poly ethylene naphthalate (PEN). In addition, thermoplastic polymers that can form an optically anisotropic melt phase, so-called thermoplastic liquid crystal polymers, and polyether ether ketone (PEEK) polymers are also suitable as the thermoplastic resin. Since all of the polymer films described above have low water absorption, they can be applied to wet methods (such as electroplating and electrodeposition).

  Moreover, in the base film of the metal-clad laminate described above, for example, by roughening the film surface, a metal-clad laminate with improved adhesion between the film and the metal layer can be produced.

  Here, as a method for roughening the film surface, for example, a method of immersing the film in an etching solution is easy and desirable. As the etching solution, a strong alkaline solution, a permanganate solution, a chromate solution, or the like is used. In particular, in the case of a thermoplastic liquid crystal polymer film, it is effective to use a strong alkali solution. For films that are difficult to etch, a mechanical polishing method such as sandblasting is effective.

  The metal layer formed on the surface of the base film described above is, for example, a Ni—P alloy layer, a Cu layer or the like as a single metal layer, and a Ni—P alloy base metal layer and Cu as a plurality of metal layers. A combination of upper metal conductive layers. When the metal layer is a Cu layer, a metal-clad laminate having a good quality conductive layer is produced. When the metal layer is a Ni-P alloy layer, a metal-clad laminate having sufficient adhesion to the base film is produced. When the metal layer is a layer formed by a combination of a Ni-P alloy base metal layer and a Cu upper metal conductive layer, the metal-clad laminate having sufficient adhesion to the base film and having a good quality conductive layer is provided. Manufactured.

  Moreover, after forming a base metal layer on at least a part of the surface of the above-described flexible thermoplastic polymer film, it is 35 to 85 ° C. lower than the melting point temperature Tm of the base film of the metal-clad laminate. After performing the heat treatment by setting the peak temperature in the range, that is, in the range of (Tm-85) to (Tm-35) ° C., preferably in the range of (Tm-70) to (Tm-50) ° C., the metal A layer may be formed.

  Moreover, after forming a base metal layer on at least a part of the surface of the above-described flexible thermoplastic polymer film, a copper layer is formed by electrolytic plating, and then a heat treatment at 150 ° C. to 200 ° C. is performed. The copper layer portion may be recrystallized.

  In addition, as described above, when heat treatment and cooling treatment are performed on the metal-clad laminate, it can be performed in an active atmosphere such as in the atmosphere, but in order to prevent discoloration and surface oxidation of the metal layer, it is inactive. It is desirable to carry out under an atmosphere. Here, the inert atmosphere means in an inert gas such as nitrogen or argon or under reduced pressure, and means that the active gas such as oxygen is 0.1% by volume or less. In particular, as the inert gas, heated nitrogen gas having a purity of 99.9% or more is preferably used.

  The metal-clad laminate described above can be used as a single-sided flexible substrate by forming a metal layer only on one side of the base film, or can be used as a double-sided flexible substrate by forming a metal layer on both sides of the base film. it can. Further, a plurality of laminated bodies in which a metal layer is formed only on one side can be overlapped and used as a multilayer substrate.

  Moreover, it is possible to form a through hole in the metal-clad laminate manufactured by the method as described above. As a method for forming a through hole, processing by a drill and processing by a laser can be used.

  Moreover, as a use of the metal-clad laminate described above, it can be used for COF, TAB, and laminates in addition to the flexible substrate described above.

Hereinafter, the present invention will be described in more detail with reference to examples.
First, VecsterCT (thickness 50 μm) manufactured by Kuraray Co., Ltd. is used as a base film (polymer film) with a width of 300 mm. This polymer film is immersed in an alkaline solution (KOH 400 g / liter) at 80 ° C. for 15 minutes to form irregularities (surface roughness Rz = 1.0 to 1.5) on the surface. Next, a film metal-clad laminate was manufactured by sequentially performing a conditioner treatment, an electroless plating treatment of a Ni-P alloy, an electroplating treatment of Cu, and a heat treatment. In each treatment, washing with water or drying was performed. Moreover, the metal layer (underlying metal layer + upper metal conductive layer) was formed on both surfaces of the polymer film.

  In the conditioner treatment, the surface of the polymer film was washed with an OPC-350 conditioner manufactured by Okuno Pharmaceutical Co., Ltd. Here, an OPC-80 catalyst manufactured by Okuno Pharmaceutical Co., Ltd. was used as a catalyst-providing liquid containing palladium, and an OPC-500 accelerator was used as an activator.

  Next, a base metal layer was formed by electroless plating, and then a Cu layer was formed by electrolytic plating for evaluation. The base metal layer is Ni-P alloy plating.

  For the electroless plating treatment of the Ni-P alloy, an Enplate NI-426 bath manufactured by Meltex Co., Ltd. was used. The pH of the plating bath was adjusted to a range of 6.0 to 7.0 using sulfuric acid or aqueous ammonia, and the bath temperature was adjusted to 75 ° C to 85 ° C. The plating thickness was 0.1 to 0.5 μm.

After performing the above-mentioned Ni-P alloy plating, Cu plating was performed in a plating bath having the following plating bath compositions 1 to 3 so that the plating thickness was 8 μm, and a copper-clad laminate was manufactured.
In addition, the carbon content in the copper film of the produced copper clad laminate was measured by EMIA-U511 manufactured by Horiba, Ltd. under the following conditions.

In the measurement, the metal layer was peeled from the degreased copper clad laminate, and the infrared absorption of CO ₂ gas generated by the electric furnace combustion in the oxygen atmosphere was measured for the peeled metal film, and converted into the amount of carbon. Measurement conditions are as follows: standard sample name: JSS200-11, standard value: 56.00 ppm, auxiliary combustor: no measurement, calibration: Sn 0.5 g, use of oxygen purifier, C: INT. TIME = 60 sec, FURNACE TEMP 1250 ° C., C: COMP. LVL = 0.0% and WAIT TIME = 0 sec.

As the plating bath for the measurement, the compositions of plating compositions 1 to 3 were used. The plating composition 1 is as follows. That is, the plating bath was Cu 70 to 130 g / liter, H ₂ SO ₄ 80 to 140 g / liter, 3-mercapto 1-propanesulfonic acid sodium 0.5 to 5 ppm, hydroxyethylene cellulose 1 to 10 ppm, low molecular weight glue (molecular weight 3000) ) 1-5 ppm, chloride ion 5-50 ppm. The current density was 1 to 7 A / dm ² , and the bath temperature was 20 to 40 ° C.

The carbon content of the metal film obtained by peeling off the metal layer of the metal-clad laminate obtained by applying copper plating with the plating composition 1 at a current density of 5 to 7 A / dm ² was C = 14 ppm.

The amount of carbon of the metal film obtained by peeling off the metal layer of the metal-clad laminate obtained by applying copper plating with the plating composition 1 at a current density of 3 to 5 A / dm ² was C = 10 ppm.

The carbon content of the metal film obtained by peeling off the metal layer of the metal-clad laminate obtained by applying copper plating with the plating composition 1 at a current density of 1 to 3 A / dm ² was C = 6 ppm.

The plating composition 2 is as follows. That is, the plating bath was Cu 70 to 130 g / liter, H ₂ SO ₄ 80 to 140 g / liter, 3-mercapto 1-propanesulfonic acid sodium 0.5 to 5 ppm, hydroxyethylene cellulose 5 to 10 ppm, low molecular weight glue (molecular weight 3000) ) 10-15 ppm, chloride ion 5-50 ppm. The current density was 1 to 15 A / dm ² , and the bath temperature was 40 to 60 ° C.

The carbon content of the metal film obtained by peeling off the metal layer of the metal-clad laminate obtained by applying copper plating with the plating composition 2 at a current density of 1 to 5 A / dm ² was C = 18 ppm.

The plating composition 3 is as follows. That is, the plating bath was Cu 70 to 130 g / liter, H ₂ SO ₄ 80 to 140 g / liter, 3-mercapto 1-sodium propanesulfonate 0.5 to 5 ppm, hydroxyethylene cellulose 10 to 15 ppm, low molecular weight glue (molecular weight 3000) ) 15-20 ppm, chloride ion 5-50 ppm. The current density was 1 to 15 A / dm ² , and the bath temperature was 20 to 40 ° C.

  When the amount of carbon in the metal film obtained by peeling off the metal layer of the metal-clad laminate subjected to copper plating with the plating composition 3 was measured, C = 25 ppm.

The plating composition 4 is as follows. That is, the plating bath was Cu 20 to 40 g / liter, H ₂ SO ₄ 80 to 140 g / liter, and chloride ions 5 to 50 ppm. The current density was 1 to 7 A / dm ² , and the bath temperature was 20 to 40 ° C.

  When the amount of carbon of the metal film from which the metal layer of the metal-clad laminate that had been plated with copper with the above plating composition 4 was peeled was measured, C = 1 ppm.

In addition, after manufacturing a metal-clad laminate by the above method, heat treatment may be performed at a high temperature of 150 ° C. to 200 ° C. in an N ₂ atmosphere to recrystallize the metal layer.

  The metal-clad laminate produced by electrolytic plating in the above plating bath compositions 1 to 4 and heat-treated after plating was subjected to a bending resistance test under the following conditions to evaluate the number of bendings.

  Using an FPC high-speed bending tester SEK-31B2S manufactured by Shin-Etsu Chemical Engineering Co., Ltd., the MIT folding resistance test was performed under the following conditions, and the number of times at the break point was defined as the number of bending times. Test conditions were in accordance with JIS C 5016. L / S = 0.6 mm / 0.6 mm, the base film thickness was 50 μm, AD = 35 μm, and the point at which the conductor resistance increased by 10% was defined as the breaking point.

  In addition, the evaluation of the surface roughness was performed by measuring Rz, which is 50 mm long in each of the longitudinal (MD) direction and the width (TD) direction, at an arbitrary position of the metal-clad laminate three times with a physical surface roughness meter, and calculating an average value thereof. I took.

Example 1
The results are shown in Table 1. All examples in Table 1 relate to the metal-clad laminate shown in FIG. 1A, and the thickness of the metal layer (copper layer) is 8 μm.

Invention Examples 1 to 5 are examples of metal-clad laminates (invention example 1) in which copper plating was performed at a current density of 5 to 7 A / dm ² in a plating bath having a plating bath composition 1, and heat treatment was not performed after copper plating. Example of metal-clad laminate subjected to heat treatment at 150 ° C. for 1 hour after copper plating (Invention Example 2), Example of metal-clad laminate subjected to heat treatment at 200 ° C. for 1 hour after copper plating (Invention Example 3) To 5) respectively.

Invention Examples 6 to 10 are examples of metal-clad laminates (invention example 6) in which copper plating was performed at a current density of 3 to 5 A / dm ² in a plating bath having a plating bath composition 1 and heat treatment was not performed after copper plating. Example of metal-clad laminate subjected to heat treatment at 150 ° C. for 1 hour after copper plating (Invention Example 7), Example of metal-clad laminate subjected to heat treatment at 200 ° C. for 1 hour after copper plating (Invention Example 8) To 10).

Invention Examples 11 to 15 are examples of metal-clad laminates (invention example 11) in which copper plating is performed at a current density of 1 to 3 A / dm ² in a plating bath having a plating bath composition 1 and heat treatment is not performed after copper plating. Example of metal-clad laminate subjected to heat treatment at 150 ° C. for 1 hour after copper plating (Invention Example 12), Example of metal-clad laminate subjected to heat treatment at 200 ° C. for 1 hour after copper plating (Invention Example 13) To 15) respectively.

Comparative Examples 1 to 3 are examples of metal-clad laminates in which copper plating is performed at a current density of ² to 7 A / dm ² in a plating bath having a plating bath composition 2 and heat treatment is not performed after copper plating (Comparative Example 1). Example of metal-clad laminate subjected to heat treatment at 150 ° C. for 1 hour after copper plating (Comparative Example 2), Example of metal-clad laminate subjected to heat treatment at 200 ° C. for 1 hour after copper plating (Comparative Example 3) ) Respectively.

Comparative Examples 4 to 6 are examples of metal-clad laminates in which copper plating was performed at a current density of ² to 5 A / dm ² in a plating bath having a plating bath composition 3 and heat treatment was not performed after copper plating (Comparative Example 4). Example of metal-clad laminate subjected to heat treatment at 150 ° C. for 1 hour after copper plating (Comparative Example 5), Example of metal-clad laminate subjected to heat treatment at 200 ° C. for 1 hour after copper plating (Comparative Example 6) ) Respectively.

Comparative Examples 7 to 9 are examples of metal-clad laminates (Comparative Example 7) in which copper plating was performed at a current density of ² to 3 A / dm ² in a plating bath having a plating bath composition 4 and heat treatment was not performed after copper plating. Example of metal-clad laminate subjected to heat treatment at 150 ° C. for 1 hour after copper plating (Comparative Example 8), Example of metal-clad laminate subjected to heat treatment at 200 ° C. for 1 hour after copper plating (Comparative Example 9) ) Respectively.

Comparative Example 10 is a metal-clad laminate in which copper plating is performed at a current density of 7 to 11 A / dm ² in a plating bath having a plating bath composition 4. Comparative Example 11 is a metal-clad laminate obtained by performing copper plating at a current density of 0.3 A / dm ² in a plating bath having a plating bath composition 4.

  As can be seen from Table 1, in Invention Examples 1 to 15, the number of bendings was 5000 or more, and the surface roughness was 2.5 μm or less. That is, in Invention Examples 1 to 15, a metal-clad laminate having good flexibility and a moderately smooth surface could be produced.

  Moreover, in Comparative Examples 1-6, all the bending | flexion frequency | counts did not reach 5000 times, and it turned out that it is difficult to apply as a metal-clad laminated body for circuit boards. In Comparative Examples 7 to 9, the surface roughness was as rough as 2.5 μm or more, and it was found difficult to apply as a metal-clad laminate for circuit boards.

  Further, in Comparative Example 10, the metal-clad laminate was deformed by heat generation during electrolytic plating, and the shape was uneven or partly perforated, so it was not possible to evaluate, and it was clearly inferior as a metal-clad laminate. I found out that In Comparative Example 11, it was found that the base layer and the copper layer of the metal-clad laminate were peeled off, and the metal-clad laminate was clearly defective due to poor adhesion.

(Example 2)
In the production of a metal-clad laminate, the base film is a liquid crystal polymer, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polyether ether ketone (PEEK) film, and each is based on the above production method. Then, a base plating layer was formed, and copper plating was performed at a current density of 5 to 7 A / dm ² in the plating bath having the plating bath composition 1 described above to produce a metal-clad laminate and evaluated. Table 2 shows the results.

  Here, Invention Example 16 is a metal-clad laminate in which a liquid crystal polymer is applied to a base film. Invention Example 17 is a metal-clad laminate in which polyethylene terephthalate (PET) is applied to the base film. Invention Example 18 is a metal-clad laminate in which polyethylene naphthalate (PEN) is applied to the base film. Invention Example 19 is a metal-clad laminate in which polyether ether ketone (PEEK) is applied to the base film.

  As can be seen from Table 2, in Invention Examples 16 to 19, the number of bendings was 5000 or more, and the surface roughness was 2.5 μm or less. That is, in Invention Examples 16 to 19, a metal-clad laminate having good flexibility and a moderately smooth surface could be produced.

Claims (8)

Polyester film, thermoplastic liquid crystal polymer film, or polyether ether
A flexible metal-clad laminate in which a base metal layer is formed on at least a part of the surface of a thermoplastic film as a base material selected from a ketone polymer film , and a copper layer is formed thereon,
The average crystal grain size of the copper layer is increased toward the thickness direction from the substrate side, Ri average range der least 5μm below 2μm grain size of the copper layer,
The metal-clad laminate, wherein the copper layer has an average carbon concentration in the range of 3 ppm to 15 ppm . The base metal layer is a layer made of a Ni-P alloy.
Metal-clad laminate. The surface of the thermoplastic film has a surface roughness Rz of 1.0 to 1.5.
The metal-clad laminate according to claim 1 or 2. The copper layer is composed of at least two layers, and the average crystal grain size of the copper layer increases sequentially from the substrate side.
The metal tension according to any one of claims 1 to 3, wherein the metal tension is
Laminated body. The base metal layer and the copper layer are provided on both surfaces of the thermoplastic film.
The metal-clad laminate according to any one of claims 1 to 4, characterized by: The metal tension of any one of Claims 1 thru | or 5 used as an electronic component use.
Laminated body. Polyester film, thermoplastic liquid crystal polymer film, or polyether ether
Base metal on at least a part of the surface of the thermoplastic film selected from ketone polymer film
A method for producing a flexible metal-clad laminate in which a metal layer is formed and a copper layer is formed thereon.
And
The thermoplastic film is immersed in an alkaline solution and is exposed on the surface of the thermoplastic film.
Forming irregularities with a surface roughness Rz of 1.0 to 1.5,
Forming a base metal layer on the surface of the thermoplastic film;
In forming the copper layer on the base metal layer by electrolytic plating, an average car in the copper layer is formed.
The plating bath is composed so that the Bon concentration is 15 ppm or less, and the current when forming the copper layer
Density 0.5-10A / dm ² And the current density increases from the substrate side toward the surface.
As a result, the average crystal grain size of the copper layer is increased in the thickness direction from the base material side.
The average crystal grain size of the copper layer is 2 μm or more and 5 μm or less, and the average carbon of the copper layer
A method for producing a metal-clad laminate, wherein the concentration is in the range of 3 ppm to 15 ppm.
Law. After the formation of the copper layer, heat treatment at 150 ° C. to 200 ° C. is further performed under an inert atmosphere.
The method for producing a metal-clad laminate according to claim 7 .

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