JP2621950B2 - Flexible metal and plastic laminates - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a flexible metal plastic laminate (FMCL = Flexible Metal Clad La) having excellent dimensional stability.
minate).

[Conventional technology]

It is composed by laminating a metal layer and a plastic film
FMCL is widely used in packaging materials, flexible printed circuit boards (flexible printed wiring boards), electromagnetic wave shielding conductor coating materials, electromagnetic wave shielding films, and other materials that make full use of the characteristics of both metals and plastics. ing.

These FMCLs require that the dimensions of both the metal layer and the plastic layer be in an appropriate relationship to one another for their processing means and applications.

However, due to the difference in the coefficient of thermal expansion between metal and plastic, or the difference in tensile strength, compressive strength, elastic modulus, etc., the dimensions of both are out of the desired and appropriate range. We are struggling to deal with the problems caused by this.

If the dimensions are different, for example, as described in detail below, if the FMCL curls greatly with the plastic layer inside, or if the metal layer is partially removed by etching, a large number of Wrinkles occur, making subsequent processing such as cutting, pattern application, sticking, stacking, element mounting, pattern connection, etc. very difficult.

Thus, these dimensional differences (dimensional differences) cannot be measured accurately in the state of the FMCL laminate, but each of the constituent metal layers or plastic layers is separated by a method that does not generate stress, and is used alone. If
Can be measured precisely.

In many cases, the dimensions of the plastic layer are below a reasonable limit compared to that of the metal layer and are generally shorter than the metal layer.

Since it is usually difficult to completely separate and singly separate each component by a method in which stress is not newly generated, an approximation method of approximation in which it is considered that substantially no stress is generated is used for measuring these dimensional differences. The following method is adopted.

That is, the dimensions of the laminate are measured in the FMCL state, and the measured values are regarded as the dimensions of the metal layer (that is, equal to the dimensions of the plastic layer before etching). The plastic layer is singulated by etching to remove the metal layer and the dimensions are measured, and the measured value is regarded as the plastic layer dimension.

From this, the dimensional difference between the two is determined (this is equal to the length of the plastic layer before etching minus the length of the plastic layer after etching).

That is, the dimensional difference in the present invention is expressed by the length of the plastic layer before etching minus the length of the plastic layer after etching.

In the present invention, as described above, it is general that the plastic layer is shorter than the metal layer, but if this dimensional difference is used, Is defined as

The adverse effects caused by the high shrinkage of the plastic layer are roughly classified into the following two items.

a) The FMCL is curled with the plastic layer inside.
Cutting, patterning, pasting, piling, and other processes are extremely difficult.

b) Flexible printed wiring board (hereinafter abbreviated as FPC).
= Flexible Printed Circuit) as a representative, drawing a precise circuit pattern with etching resist ink,
Next, when the metal layer is partially left after the etching, the entire surface is wrinkled due to a dimensional change in a part where the metal layer is present and a part where the metal layer is not present.

Therefore, the relative positional relationship between the points on the pattern changes, and the precision required for component mounting or connection with another pattern is lacking, and its appearance is unsightly.

If the dimensions of the plastic layer are smaller than the dimensions of the metal layer by more than a certain size, it can be said that there is little practical utility.

In some cases, various measures have conventionally been taken to eliminate the above-mentioned fatal drawbacks as products, but FMCL with satisfactory properties has not yet been completed.

As an example of a known technique, as a simple method for removing curl, as shown in JP-A-59-22388 and JP-A-59-22389, a `` bending plastic deformation '' opposite to curl is applied to a metal layer. Giving, i.e., bending the curled metal layer back against the curl and balancing the degree of curl by balancing the stress causing the curl formation based on the dimensional difference between the metal layer and the plastic. There are ways to reduce it.

In this case, it should be noted that, of course, there is no substantial change in the dimensions of the metal layer itself before and after processing.

That is, in the FMCL treated by such a method, only the curl of the above a), which is an adverse effect due to the small size of the plastic layer, is only seemingly erased temporarily. . However, the curl returns to its original state immediately after the heat history.
The formation of wrinkles at the time of etching in b) is because the dimensional difference between the plastic layer and the metal layer is the same as before the treatment, and is an essential drawback due to no fundamental improvement in properties. is there.

On the other hand, some attempts have been made to selectively stretch only the plastic layer to approach the dimensions of the metal layer.

In Japanese Patent Application Laid-Open No. 56-27391, the size of a plastic layer is made to approach the size of a metal layer by absorbing a solvent, expanding the plastic layer and stretching the plastic layer.

However, in this method, the FMCL is heated to a high temperature, for example, 10
Solvent absorbed by exposure to an atmosphere of 0 ° C or higher or being left in the air for a long time inevitably escapes from the plastic layer, so the plastic layer contracts again. In addition, there is a disadvantage that it is extremely difficult to reduce the dimensional difference between the metal layer and the metal layer to a required predetermined range by this treatment.

Japanese Patent Application Laid-Open No. 54-108272 discloses a method of reducing the dimensional difference by winding the plastic layer outward, holding the plastic layer at a high temperature for a long time, and continuously annealing the plastic layer in a stretched state. No. 54-111163, but has the disadvantage that the plastic layer contracts again due to the difference in the coefficient of thermal expansion between the metal and the plastic when cooled to room temperature, so that the dimensional difference is hardly reduced.

Further, Japanese Patent Application Laid-Open No. 62-299338 proposes a method in which a thin metal layer is provided on a support, a polyimide solution or a polyimide precursor solution is applied thereto, and the support is removed after heating and drying. However, in this method, the dimensions of the polyimide layer become shorter than the metal layer during cooling due to the difference in the coefficient of thermal expansion between the polyimide layer and the metal layer, and the polyimide layer curls inward.

In addition, when a part of the metal layer is removed by etching, the polyimide layer which has lost the metal layer and becomes naked shrinks, causing dimensional change and wrinkles.

[Disclosure of the Invention]

As a result of intensive studies in view of such points, the inventors did not stretch the plastic layer as in the past, but rather, on the contrary, took a measure based on the idea of `` compressing '' the metal layer, Surprisingly, they have found that a laminate can be obtained in which all of the aforementioned disadvantages are drastically eliminated and have completed the invention.

That is, the FMCL of the present invention is essentially clearly different from that obtained by the prior art, and in a flexible laminated plate in which a plastic layer and a metal layer are laminated, the metal layer is subjected to compression plastic deformation. There is a remarkable feature in what has been done.

More specifically, in a flexible laminated plate in which a plastic film and a metal layer are laminated directly or via a coupling layer or an adhesive layer, the longitudinal direction and / or width direction of the metal layer remain laminated. Is 0.
In the range of 001 to 5%, preferably 0.01 to 5%, depending on the application, it is compressed by plastic deformation to approach or conform to the dimensions of the plastic layer, and even shrink more than the plastic layer. The aforementioned shrinkage is preferably ± 0.3
% Or less.

The term “compression plastic deformation” as used in the present invention means, in terms of material mechanics, for example, a deformation that occurs as a result of a compressive load applied to a metal layer and undergoes a compressive stress, and remains after the load is removed.

This is mainly referred to as shrinkage plastic deformation because the deformed metal layer mainly causes shrinkage, and both compression and shrinkage are exactly the same in technical meaning.
However, it is considered that the technical features of the present invention are more appropriately and clearly expressed, and it is troublesome to always describe compression (shrinkage) plastic deformation. Therefore, in this specification, the term compression plastic deformation is used. Will be described.

The most significant feature of the flexible metal plastic laminate of the present invention is that the metal layer is compressed and undergoes plastic deformation, that is, is subjected to compression plastic deformation. Deformation rate is 0.001-5
%, Preferably 0.01 to 5%, more preferably 0.01 to 1%
It is.

If it is less than the minimum of this range, it is difficult to realize the effect of the present invention. On the other hand, it is not technically preferable to greatly exceed the maximum value of this range. It was confirmed that it was possible to perform plastic deformation up to 8.2%.

The compression plastic deformation rate of the metal layer is defined by the following equation.

The metal layer of the present invention is a so-called metal foil. As the metal used for the metal layer, the smaller the plastic deformation stress is, the easier the compression plastic deformation is, and the metal layer conforms to the method of eliminating the dimensional difference of the present invention. .

For example, copper, aluminum, nickel, gold, silver and alloys containing these have low plastic deformation stress and good electrical properties, and are therefore preferably used as the FMCL of the present invention.

The metal layer of the FMCL of the present invention may be used as a plurality of types of metal layers (a large number of metal layers).

The thickness of the metal layer of the laminate of the present invention is generally about 0.05 to 100 μm. That is, a so-called ultrathin metal foil having a thickness of about 0.05 to 10 μm, preferably about 0.05 to 4 as well as a so-called thick material having a thickness of about 10 to 100 μm which has conventionally been generally available. The laminated plate of the present invention can be provided as a good product. However, the greatest technical feature of the present invention is that the metal layer is `` compressed and plastically deformed '' because it has a thickness that allows the metal layer to be compressed and plasticized.
It will be easy for a person skilled in the art to understand that the present invention can be suitably applied to a metal foil having a generally available thickness as well as a thicker or even thinner metal foil.

The FMCL of such an ultra-thin metal layer should be easy to manufacture as a flexible printed circuit board with a fine pattern, be low-cost in pattern etching, and be flexible and insertable into a narrow space. In recent years, its demand has rapidly increased because of its advantageous features such as being capable of precise bending by a small force.

On the other hand, the thickness of the plastic layer in the laminate of the present invention is in the range of 1 to 200 μm, preferably 3 to 100 μm, more preferably 5 to 50 μm, and if it is too thin, it can act as a support. If it is too thick, handling and processing become difficult.

Examples of the plastic used in the present invention include, for example, polyimide, polyaramid, polyamideimide, polyester, polyarylate, polyethersulfone, polyetheretherketone, polyphenylene sulfite, polyparabanic acid, polypropylene, polyethylene, polystyrene, and polyvinyl chloride. , Polytetrafluoroethylene, polytetrafluoroethylene chloride, polytetrafluoroethylene.
There are propylene hexafluoride copolymer, polyvinylidene fluoride and the like, but of course, it is not limited to these.

In the present invention, the plastic layer may be composed of a plurality of different types of layers, or may be a mixture or a copolymer thereof. For example, polyimide-polyamide and polyimide-polyamide-imide. In the present invention, usually,
The lamination of the plastic thin layer and the metal layer may be performed with an adhesive, or a method in which the plastic thin layer and the metal layer are directly fixed and laminated.

In this case, a method in which a polymer varnish is applied and dried by heating and cured, or a method in which a molten polymer is extruded on a metal foil is used. In the present invention, any of the above means can be used.

In the case of a so-called ultra-thin metal foil having a thickness of 0.05 to 10 μm, it is difficult to handle the metal foil by itself, and the following method is employed.

First, a metal layer is formed and laminated on a plastic layer by sputtering or vacuum evaporation.

In the case of the sputtering method, the metal layer thickness is 0.05 to 4 μm.
An extremely thin foil of about m is suitably manufactured.

Such an ultra-thin metal by sputtering or the like is formed by forming an electrolytic plating layer on the ultra-thin metal as necessary and increasing the thickness to a desired thickness. In addition,
The plating layer may be formed by electroless plating.

In the above-mentioned sputtering, a voltage is applied between the anode and the metal using the metal foil as a cathode in an atmosphere of argon gas or the like under reduced pressure, and a low-pressure gas discharge, that is, a glow discharge is caused to generate ions into the cathode metal. This is a method for producing a flexible metal-plastic laminate in which the metal is caused to collide and precipitate on the surface of a plastic layer.

Vacuum evaporation is a method in which a metal is heated and evaporated in a vacuum to solidify and deposit on the surface of a plastic layer to produce a flexible metal-plastic laminate.

The second method of forming an extremely thin metal layer on a plastic layer is a plating method. A thin metal layer formed by electroless plating on a plastic layer is used. The electroless plating layer may be electrolytically plated thereon to increase the thickness of the metal layer, if necessary.

On the other hand, a metal foil sheet in which a metal layer is formed by electroplating or vacuum evaporation on a conductive support made of relatively thick aluminum or the like, despite the fact that the metal layer is extremely thin, the aluminum foil of the support, etc. Due to the rigidity of the sheet, the sheet as a whole has a certain degree of rigidity and can be easily handled alone, and is suitably used for the laminate of the present invention.

For example, 5 copper on aluminum with a thickness of about 40 μm
Metal foil sheets formed to a thickness of about 9 μm by electrolytic plating are manufactured at low cost and are preferably used.

Such a metal foil sheet, for example, by directly applying a solvent solution of a plastic on a copper layer of an aluminum copper foil sheet by a known method, and after heating and drying, by removing the aluminum serving as the conductive support, It is the material of the plastic laminate that is the subject of the invention.

Note that the support may be removed by etching or peeling off by applying an external force.

When a plastic solvent solution is applied on the metal layer, it is effective to interpose a thin layer of the coupling agent between the metal layer and the plastic layer in order to improve the adhesiveness.

The coupling layer does not necessarily need to be in contact with the plastic layer over the entire surface, and a thin metal layer such as a rust-proof plating film may be partially interposed between the coupling layer and the plastic layer.

In order to improve the adhesiveness, a nitrogen-containing silane coupling agent is most effective. When subjected to compression plastic deformation, a flexible metal-plastic laminate having good adhesion between the metal layer and the plastic layer and excellent dimensional stability is provided.

The main use of the FMCL according to the present invention is FPC, and the tensile strength of the plastic layer serving as the substrate is 10 kg / m.
m ² or more, tensile modulus is 100 kg / mm ² or more, tensile elongation is 1
Preferably, the glass transition point is 0% or more, the glass transition point is 100 ° C. or more, and the insulating property is a volume resistivity of 10 ¹⁰ Ωcm or more.

The FMCL according to the present invention does not contain a solvent, and is not due to apparent curl removal due to mild bending plastic deformation of the metal foil. The shape does not decrease and disappear over time, the shape is extremely stable, and the dimensions of the metal foil and the plastic layer constituting the FMCL are stabilized.

When this FMCL is applied for FPC, the mutual positional relationship between points in a pattern on a metal foil is stabilized, and mounting of components and connection with another substrate are performed with high precision.

In addition, as an FMCL for general use, it has a stable flatness even after a severe heat history, and thus has excellent handling and workability during processing.

Conventionally, USP3179634, JP-A-49-51559, JP-A-52
115888, 57-80049, 57-181857, 59-162
A-FMCL (Adhesiveless FMCL) which does not use a laminating adhesive provided by No. 044, Japanese Patent Application No. 61-66049, etc. has excellent performance in heat resistance, flexibility, dielectric properties, etc. Although dimensional shrinkage was not the main reason for practical use, the present invention was applied to A-
FMCL has a dimensional shrinkage ratio of a predetermined value or less, that is, ± 0.
3% or less, preferably ± 0.2% or less, more preferably ± 0.
1% or less, most preferably ± 0.05% or less.

Therefore, the FMCL itself has no curl, and, of course, no wrinkles are observed even after being etched and the metal pattern is formed, so that it becomes an ideal A-FMCL and is applied to many uses. It is expected.

In addition, when the plastic layer and the metal foil are laminated via an adhesive, the FMCL of the present invention also applies to the case where the frequently occurring plastic layer is laminated with a short dimension.
Whether the dimensions of the plastic layer are close to or matched by the compression-deformation of the metal layer,
Furthermore, it is even possible to make them relatively short.

When FMCL having an extremely small dimensional shrinkage ratio, that is, ± 0.05% or less, preferably ± 0.03% or less, is used for FPC, it is possible to form a pattern with much more severe dimensional accuracy in addition to the above effects. It is suitable for fine patterns and the like which have been in great demand recently, and the range of use is further expanded.

In particular, an FMCL having a thin metal foil has a small undercut due to the etching when the metal layer is etched into the FPC, and accordingly, a large line / interval density can be increased.

The demand for finer pattern circuits that are more precise than the current ones is increasing rapidly.In particular, in the computer field, it is required to increase the signal transmission speed and increase the function density. It is assumed that the demand for fine pattern circuits will increase.

In addition, FMCL with a thin metal layer reduces the time required for etching, and also reduces chemical consumption and wastewater treatment costs.

In addition, the ultra-thin metal layer FMCL is flexible and highly flexible, and the FPC manufactured by using it can be inserted in a narrow space without fear of disconnection, and can be inserted, helping to reduce the size of the product, As described above, the demand is rapidly increasing in recent years due to the fact that it is used in a place where it is repeatedly bent due to a large number of times of bending and the number of times of use increases, and that it can be bent with a small force.

FMCL with a thin metal layer and no use of an adhesive can provide an FPC with better flexibility as a whole, and it is assumed that the demand will increase rapidly.

In the flexible metal plastic laminate obtained by the above various methods, compression plastic deformation is caused in the metal layer, and the compression plastic deformation rate is preferably 0.01 to 5
% Is the flexible metal plastic laminate of the present invention. However, according to the present invention, the metal layer can be plastically deformed to 8.2% as shown in Example 4 described later.

Usually, it is not necessary for a person skilled in the art to consider compressing and deforming such a thin metal layer, that is, a metal foil, in the first place, and it is natural to devise means for that purpose. However, it is easily understood that this is a technical problem that is extremely difficult to realize, as a matter of course, which cannot be obvious, but in the present invention, for example, the metal layer is formed by the following very clever means. Is subjected to compression plastic deformation. However, it goes without saying that the means is not limited to this.

First, an example of a manufacturing method will be described depending on the case of a continuous sheet.

The long FMCL is abbreviated as its width direction, hereinafter TD direction,
The FMCL is bent over the edge of the first blade, which is provided as an angle within the range of 0 to 80 degrees and the radius of curvature of the functional curved surface portion of the edge is smaller than 0.5 mm, and the surface of the metal layer side The first process is to pass through while maintaining a considerable tension state by contacting the FMCL, and then provided as an angle in the range of 0 to -80 degrees with respect to the TD direction of the FMCL, and similarly, the function of the edge F on the curved surface of the second blade with a radius of curvature smaller than 0.5 mm
One or more steps are performed in which the MCL is bent and brought into contact with the metal layer side to pass through while maintaining a considerable tension state in any order.

If the plastic layer shrinks before and after etching the metal layer only in the longitudinal direction of the FMCL, hereinafter abbreviated as the MD direction, the FMCL is set to ± 5 degrees or less with respect to the TD direction, and Either the first or second processing is performed one or more times.

Surprisingly, the metal layer is compression-plastically deformed by the above processing, and the novel FMCL aimed at by the present invention is obtained.

It is considered that the technical basis of this processing is as follows.

For convenience of understanding, the description will be made on the assumption that the dimension of the plastic thin layer is only 0.5% shorter than the dimension of the metal foil only in the MD direction.

As shown in FIG. 1, FMCL is 0 in the TD direction.
Degree, that is, the metal layer side of the FMCL bends and contacts the edge of the first blade of the edge curved surface provided at a right angle to the direction in which the FMCL is advanced and having a radius of curvature smaller than 0.5 mm. Then, as shown in FIG. 2, a tensile stress acts on the plastic layer, and a contractive stress, that is, a compressive stress acts on the metal layer in a balanced manner.

As a result, the metal layer is shrunk by compressive stress.
Shrinkage (compression) plastic deformation of about 0.4%, generally about 0.01 to 5% occurs.

That is, in a flexible laminated plate obtained by laminating a plastic layer and a metal layer, a flexible layer obtained by compressing and deforming the metal layer can be obtained.

On the other hand, although the tensile stress acts on the plastic layer as described above, the effect is almost entirely limited to the elastic deformation, and the dimensions are not substantially changed. These results are combined, and only plastic deformation of the metal layer is 0.
It remains as shrinkage (compression) of about 01 to 5%, and the dimensional difference between the plastic layer and the metal layer decreases, and the shrinkage rate of the plastic layer decreases by about 0.1%, generally ± 0.3% or less. The curl is essentially removed.

This is because, when the dimensions of the FMCL that has been subjected to the compression plastic deformation treatment of the metal layer as described in the examples below are actually measured, there is a shrinkage of about 0.01 to 5% in the MD direction as in the case of the metal layer. It is confirmed.

The dimensions of the plastic layer follow the dimensions of the metal layer because the plastic layer always has a tendency to shrink in the MD and because the elastic modulus of the metal layer is greater than that of the plastic layer. Would.

In the case of an extremely thin metal layer FMCL, as shown in FIG.
The thickness of the tip is about 0.01 mm to 0.7 mm, preferably 0.1 mm to 0.
It is preferable to perform the same treatment as above using a thick blade of about 5 mm.

In the case of an FMCL in the form of a discontinuous sheet, the FMCL is sandwiched between two parallel flat plates, and the FMCL is held at a weak pressure of about the contact pressure.

 Thereafter, pressure is applied to the end face of the FMCL.

The pressure must be large enough for the metal foil to undergo compression plastic deformation, and the amount of compression is controlled by the magnitude of this pressure.

When the dimension of the plastic thin layer of the FMCL is shorter than the metal layer in both the MD direction and the TD direction, the FMCL generally depends on the degree of the length, as shown in FIG. The metal layer side passes through the small curved surface of the edge of the blade having an angle of 5 to 80 degrees with respect to the TD direction in the MD direction under tension, and the metal layer of FMCL is compressed in the a-b direction,
Next, in the TD direction of the FMCL, similarly passing on the small curved surface of the edge of the blade having an angle of -5 to -80 degrees, c-
The metal layer is compressed in the d direction.

As a result, the metal layer is compressed in all directions.

Important points in this process are the radius of curvature of the blade edge through which the metal layer passes, in other words, the tip thickness, the angle of the blade with respect to the TD direction of the FMCL, and the FM when passing through the blade edge.
The magnitude of the tension acting on CL, the passing speed, the number of passes,
These are the introduction angle (α) and the exit angle (β) shown in FIG.

These are the dimensional difference between metal layer and plastic thin layer, MD / TD
Control is performed in consideration of factors such as the size difference distribution state in the direction, the elastic modulus of each of the metal layer and the plastic layer, and the elastic limit displacement.

Since the elastic modulus of the plastic layer increases when the temperature and the humidity of the environment in which the processing is performed are low, the stress for shrinking and deforming the metal layer increases, which is advantageous for eliminating the dimensional difference.

In the present invention, the reason why the radius of curvature of the blade edge is preferably 0.5 mm or less is that when the thin FMCL passes through the curved surface of the edge, the compressive stress acting on the metal layer is increased to bend to the compression plastic deformation region of the metal. This is for increasing the degree and contracting due to strong bending. See FIG.

If the radius of curvature exceeds 0.5 mm, the compressive stress acting on the metal layer can not reach the metal layer to the compression plastic deformation area, or even if it can reach it, only a small deformation is given within a minute time This is completely ineffective in eliminating the dimensional difference.

In addition, an extremely thin metal layer with a metal layer thickness of about 0.05 to 10 μm
In the case of FMCL, the reason why a blade having a tip thickness of about 0.01 mm to 0.7 mm as shown in FIG. 2 is preferable is as follows.

In the case of the ultrathin metal layer FMCL, the plastic layer generally has almost the same thickness, so that the total thickness of the FMCL as a whole is also extremely thin.

This reduces the radius of curvature of the bending applied to the FMCL when it passes over the blade edge upper surface, increases the compressive stress acting on the ultra-thin metal layer, and reduces the degree of bending to the compression plastic deformation region of the metal as described above. This is because it is made large and contracted by strong bending. See also FIG.

However, in this case, the blade edge may not have a curvature in the thickness direction. The reason was pressed with tension
This is because the FMCL itself forms an arc of small curvature on the blade edge.

In the case where a work for giving a curvature to the blade edge in the thickness direction is applied, it is difficult to manufacture the blade as maintaining the linearity in the longitudinal direction of the blade accurately. When the edge of the blade has no curvature in the thickness direction, it is preferable to chamfer the edge of the blade to about 30 μm so as not to damage the metal layer.

The contact passage treatment as described above ensures that the dimensional difference between the plastic layer and the metal layer of the FMCL is 0.3% or less, and that even after various patterns are imparted to the metal layer, irregularities or wrinkles may occur on the FMCL. It can be used for many purposes, especially for FPC.

Hereinafter, specific embodiments of the present invention will be described with reference to examples.

Example 1 421 g (2.1 mol) of 4,4'-diaminodiphenyl ether was dissolved in 4000 ml of N-methylpyrrolidone in a closed vessel equipped with a stirrer, a reflux condenser and a nitrogen inlet tube.

In a nitrogen atmosphere, add pyromellitic dianhydride to this solution.
458 g (2.1 mol) was added and reacted at room temperature for 24 hours. The logarithmic viscosity of the polyimide acid solution obtained after the reaction is
It was 1.8 dl / g.

18% of this polyimide acid solution with N-methylpyrrolidone
And the rotational viscosity was adjusted to 110,000 cps.

The solution thus obtained is uniformly cast on a 35 μm-thick electrolytic copper foil (HTE copper foil manufactured by Mitsui Mining & Smelting Co.), heated at 130 ° C. for 5 minutes, and further heated at 180 ° C. for 5 minutes and dried. After that, in a nitrogen atmosphere at 360 ° C with an oxygen concentration of 2%,
Heat for 60 minutes, polyimide coated thickness 60
A μm FMCL was obtained.

When the A-FMCL thus obtained was cut into a square substrate of 24 × 24 cm, curls having a radius of curvature of 1.5 cm with the polyimide thin layer inside were generated in both the TD direction and the MD direction. The dimensional shrinkage of the polyimide thin layer was 0.55%.

The amount of residual pyrrolidone in the polyimide thin layer was 0.01%
Met.

This long product of A-FMCL was slit with a slitter of 24 cm width and wound up on a roll.

As shown in FIG. 6, a part of the A-FMCL wound on the roll was marked with points A, B, C and D, and the distance between the points was measured and recorded. AB, BD, DC
And CA were isometric and 23.000 cm each.

Thereafter, the A-FMCL wound on this roll is fixed at an angle of 40 degrees with respect to the TD direction, the cross section is 0.6 mm in width and 50 mm in length, and the radius of curvature of the functioning edge is
The first blade made of zirconia having a thickness of 0.05 mm was passed through at an introduction angle of 60 degrees and an extraction angle of 60 degrees while contacting the surface of the copper foil as the metal layer.

At this time, the A-FMCL has 12 kg in the traveling direction, that is, 0.5 k
A g / cm width tension was applied.

After passing through the first blade, the same as in the first blade while contacting the surface of the copper foil layer as a metal layer with a second blade of the same shape made of zirconia fixed as an angle of −40 degrees with respect to the TD direction. Under the following conditions.

The process of rubbing the edges of the two blades was repeated three times in an environment of 20 ° C. and 50% humidity, and the roll was wound again.

When the distance between each point, which was measured and recorded in advance, was measured again, it was 22.873 cm, and the plastic layer was deformed by 0.55% by compression plastic deformation, and the metal layer was subjected to compression plastic deformation. It was confirmed that a plate was obtained.

Thereafter, the marked copper foil of the A-FMCL was removed by etching, and the dimensional shrinkage of the polyimide thin layer was measured to be 0.02%.

This A-FMCL was stored at 50 ° C. for one year, but no dimensional change was observed.

The dimensional shrinkage of the polyimide thin layer before and after etching was 0.03%.

Draw a wiring pattern on this A-FMCL by the usual method
C was manufactured, but this FPC had very little unevenness on the whole and on the functional surface, and had extremely good flatness.

After this FPC was floated on the surface of the molten solder at 260 ° C. for 10 seconds, the temperature was returned to normal temperature. However, the entire surface still had very little unevenness and maintained a good flat surface.

Comparative Example 1 The procedure was the same as in Example 1 except that the radius of curvature of the functional edges of the first and second blades was changed to 5 mm.

In the obtained A-FMCL, the radius of curvature of the curl was 15 cm, and the curl was greatly attenuated.

However, the measured value of the change in distance between the four points similar to the example, 23.050 cm before blade rubbing treatment, 23.050 cm after treatment
Met.

That is, the dimensional change before and after the treatment was not substantially recognized, and there was no compression plastic deformation in the metal layer.

Therefore, it is presumed that the damping of the curl is caused not by the compression plastic deformation of the copper foil but by the bending plastic deformation thereof.

The polyimide thin layer shrinkage before and after the etching of the A-FMCL was 0.55%, which was the same as before the treatment with the blade, and the shrinkage was not improved at all. In addition, the wiring pattern was drawn and FPC was performed in the same manner as in the example. However, since there were very large irregularities, the mounting of components and the connection of the wiring pattern were seriously hindered, and were unusable.

[Comparative Example 2] An A-FMCL of a polyimide thin layer / copper foil was prepared in the same manner as in Example 1.

The A-FMCL a polyimide thin layer on the tube wall outer surface of a SUS tube having an outer diameter of 55mm is wound as an outer, inserted into the autoclave by injecting N- methylpyrrolidone 1 m ² per 6g of A-FMCL, Heat treatment was performed at 150 ° C. for 72 hours.

The curl radius of curvature of the obtained A-FMCL was 7 cm.

Further, the amount of N-methylpyrrolidone remaining in the plastic thin layer after the heat treatment was 1.3%.

The dimensions between the four points were measured in the same manner as in the example, and the change before and after the high-temperature solvent treatment was examined, but there was no change at all.

The shrinkage of polyimide before and after etching is 0.32%
Met.

Furthermore, a wiring pattern was drawn in the same manner as in the example, and the FPC was used. However, it was confirmed that the method was not practical because of very large irregularities.

After the A-FMCL of this comparative example was floated on the molten solder at 260 ° C. for 30 seconds and then returned to room temperature, the radius of curvature of the curl was reduced to 2 cm, and the curl became stronger. When the residual amount of N-methylpyrrolidone was measured, it was reduced to 0.5%.

[Example 2] The polyimide acid solution obtained in the same manner as in Example 1 was uniformly applied to an ultra-thin copper foil having a thickness of 9 µm and a total thickness of 49 µm UTC copper foil manufactured by Mitsui Kinzoku Mining Co., Ltd. with an aluminum support having a thickness of 40 µm. After heating and drying at 130 ° C. for 5 minutes and further at 180 ° C. for 5 minutes, it was heated in a nitrogen atmosphere at 360 ° C. with an oxygen concentration of 2% for 5 minutes to obtain a polyimide coated thickness. 55 μm FMCL was obtained. Next, using 10% caustic soda, aluminum was removed by etching to obtain an ultra-thin A-FMCL.

When the A-FMCL thus obtained was cut into a square substrate of 24 × 24 cm, curls having a radius of curvature of 1.0 cm with the polyimide layer inside in both the TD direction and the MD direction were generated.

 The dimensional shrinkage of the polyimide layer was 0.6%.

The residual amount of pyrrolidone in the polyimide layer is 0.001%
It was below.

This long product of A-FMCL was slit into a slitter of 24 cm width and wound on a roll.

As shown in FIG. 6, a part of the A-FMCL wound on this roll is marked with points A, B, C and D,
The distance between each point was measured and recorded.

AB, BD, DC and CA are isometric;
Each was 23.000 cm.

Thereafter, the A-FMCL wound on this roll is fixed at an angle of 40 degrees with respect to the TD direction, and has a cross section of 0.
It is a rectangle with a height of 2 mm and a height of 50 mm, and the first blade made of tool steel with a chamfer of 30 μm radius at the corner is brought into contact with the surface of the copper foil at an introduction angle of 30 degrees and an extraction angle of 30 degrees Let it pass.

At this time, the A-FMCL has 3 kg in the traveling direction, that is, 0.125.
A tension of kg / cm width was applied.

After passing the first blade, in the first blade while contacting the surface of the copper foil as a metal layer to a second blade of the same shape made of high-speed steel fixed as an angle of -40 degrees with respect to the TD direction And passed under the same conditions.

The process of scraping the edges of these two blades is performed at 20 ° C.
The film was repeatedly wound three times in a 50% humidity environment and wound up again.

When the distance between the marks, which had been measured and recorded in advance, was measured again, it was 22.862 cm, and shrinkage plastic deformation by 0.6% was observed.

Then, the copper foil of A-FMCL with this mark was removed by etching, and the dimensional shrinkage of the polyimide thin layer was measured to be 0.03%.

This A-FMCL was stored at 50 ° C. for one year, but no dimensional change was observed.

The dimensional shrinkage of the thin polyimide layer before and after the etching of the stored A-FMCL was 0.03%.

Draw a wiring pattern on this A-FMCL by the usual method
The FPC was manufactured, and this FPC had very little unevenness and good flatness both on the whole and on the functional surface.

After this FPC was floated on the surface of the molten solder at 260 ° C. for 10 seconds, the temperature was returned to normal temperature. However, the entire surface still had very little unevenness and maintained a good flat surface.

Comparative Example 3 Except that the thicknesses of the first and second blades were 10 mm and the radius of curvature of the functional edge was 5 mm, all items were the same as in the example.

The obtained A-FMCL had a curl with a radius of curvature of 15 cm, and the curl was greatly attenuated.

However, the measured value of the distance change between the four points as in Example 2 was 23.040 cm before the blade rubbing treatment and 23.040 cm after the treatment.
Met.

That is, a change in dimensions before and after the treatment was not substantially observed, and the metal layer was not compression-plastically deformed at all. Therefore, it is presumed that the curl attenuation was not caused by the compressive deformation of the copper foil but caused by its bending plastic deformation.

The polyimide thin layer shrinkage ratio before and after the etching of the A-FMCL was 0.6%, which was the same as before the treatment with the blade, and the shrinkage ratio was not improved at all. The wiring pattern was drawn in the same manner as in Example 2 to form an FPC. However, since there were very large irregularities, the mounting of components and the connection of the wiring pattern were seriously hindered, and the FPC could not be used.

Example 3 A commercially available 25 μm thick polyimide film “KAPTON” (trademark) was used, and the copper layer thickness was 4.2 μm by a sputtering method.
m of a flexible plastic copper-clad laminate.

When this was cut into a square of 20 x 20 cm and left to stand, MD
Curling occurred in the direction with the copper layer as the outer side, resulting in a cylinder having a diameter of 50 mm.

The dimensional difference from the polyimide film was measured by etching this copper layer.
The direction was 0.09%, and the copper layer was longer in each case.

The long object of this ultra-thin A-FMCL was slit into a width of 25 cm and wound into a roll.

Using the same apparatus as in Example 2, it was passed through two blades while applying a tension of 1.5 kg.

When the dimensions were measured on the copper layer side, 0.13% in the MD direction, TD
The compression plastic deformation was 0.08% in the direction.

The copper foil was removed by etching, and the dimensional shrinkage of the polyimide layer was measured.

Both MD and TD were 0.01% based on the dimensions of the laminate before etching.

Draw a wiring pattern on this A-FMCL by the usual method
The FPC was manufactured, and this FPC had very little unevenness and good flatness both on the whole and on the functional surface.

Example 4 Commercially available polyimide film “KAPTON” having a thickness of 25 μm
First, a 0.3μm thick copper layer is deposited by electroless plating, and then a copper layer is deposited by electrolytic plating on it,
The total thickness of the copper layer was 8 μm. When this A-FMCL was left, it was curled with the copper layer facing outward.

When the copper layer was removed by etching this, the dimensional shrinkage in the MD direction was 6.7%, and the dimensional shrinkage ratio in the TD direction was 8.2%. In each case, the copper layer was longer. This A-FMCL was passed through two blades in the same manner as in Example 2.

 The tension applied during rubbing was 3 kg.

When the dimensions were measured on the copper layer side, it was found to be 6.7% in the MD direction and 8.2% compression plastic deformation in the TD direction. The copper foil was removed by etching, and the dimensional shrinkage of the polyimide layer was measured.

Both MD and TD based on the dimensions of the laminate before etching
0.02%.

Draw a wiring pattern on this A-FMCL by the usual method
The FPC was manufactured, and this FPC had very little unevenness and good flatness both on the whole and on the functional surface.

Comparative Example 4 An A-FMCL of a polyimide layer / copper foil was produced in the same manner as in Example 4. The A-FMCL by winding a thin polyimide layer as an outer insert into the autoclave in the tube wall outer surface of a SUS tube having an outer diameter of 55 mm, by implanting N- methylpyrrolidone 1 m ² per 6g of A-FMCL, 0.99 Heat treatment was performed at 72 ° C. for 72 hours.

The curl radius of curvature of the obtained A-FMCL was 7 cm.

The amount of N-methylpyrrolidone remaining in the plastic thin layer after the heat treatment was 1.2%.

As in Example 2, the dimension between the four points was measured and the change before the high-temperature solvent treatment was examined, but no change was observed.

The shrinkage of polyimide before and after etching is 0.3%
Met.

Further, a wiring pattern was drawn as in Example 2 to form an FPC. However, it was confirmed that the FPC was not practical because of very large irregularities.

When the A-FMCL of this comparative example was floated on molten solder at 260 ° C. for 30 seconds and then returned to room temperature, the radius of curvature of the curl was
It became smaller to 1.8cm and the curl became stronger.

When the amount of residual N-methylpyrrolidone was measured, it was 0.4%.
Was decreasing.

[Brief description of the drawings]

FIG. 1 is a plan view for explaining the principle of one method of manufacturing a laminate according to the present invention. FIGS. 2 and 3 are longitudinal sectional views showing stresses generated in FMCL in the process of FIG. FIG. 4 is a schematic view, FIG. 4 is a plan view for explaining an arrangement angle of a blade functioning in the first and second processes, and FIGS. 5 and 6 are an introduction angle and an extraction angle to a functional blade. 7 is a graph showing the relationship between the shrinkage stress and the amount of shrinkage, and FIG. 8 is an explanatory view of the arrangement of distance measurement reference points for a test.

Continued on the front page (72) Inventor Shunji Yoshida 2882-3-29 Iijimacho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Kenji Tanabe 1-1-15-38, Nagatahigashi, Minami-ku, Yokohama-shi, Kanagawa Prefecture (56) References Special JP-A-57-66690 (JP, A) JP-A-54-111673 (JP, A) JP-A-55-160489 (JP, A)

Claims (7)

(57) [Claims] 1. A flexible laminate in which a metal layer and a plastic layer are laminated, wherein the metal layer has a radius of curvature.
Flexible metal plastic laminate characterized in that the metal layer is brought into contact with the edge of a blade having an edge curved surface of less than 0.5 mm under tension and subjected to compression plastic deformation of 0.01 to 8.2%. . 2. When the metal layer portion of the laminate is entirely etched, the metal layer portion is subjected to compression plastic deformation, so that the shrinkage of the plastic layer is based on the dimensions of the laminate before etching. The laminate according to claim 1, wherein the thickness is ± 0.3% or less. 3. The method according to claim 1, wherein the metal layer is made of copper, aluminum, nickel,
The laminate according to claim 1, wherein the laminate is made of gold, silver, or an alloy containing these. 4. The laminate according to claim 1, wherein the thickness of the metal layer is in the range of 0.05 μm to 100 μm. 5. The plastic layer has a thickness of 1 μm to 200 μm.
The laminate according to claim 1, wherein 6. The laminate according to claim 1, wherein the plastic layer comprises a plurality of types of layers. 7. The laminate according to claim 1, wherein the plastic layer comprises a layer of polyimide, polyaramid, polyamideimide, polyester, polytetrafluoroethylene or a plurality of these layers.