JP6880723B2 - Double-sided metal laminate, double-sided metal laminate manufacturing method, and pattern image transfer method - Google Patents

Description

The present invention relates to a double-sided metal laminate, a method for manufacturing a double-sided metal laminate, and a method for transferring an image of a pattern.

Demand for miniaturization and weight reduction of portable electronic devices such as tablets, e-book readers, smartphones, MP3 players, and electronic game machines, as well as mobile communications such as mobile phones and car phones, is increasing, and electronic components are placed at minute intervals. Expectations for high-density mounting with high-density equipment are increasing. Along with this, the number of printed wiring boards has been increased, the width of the wiring pitch has been narrowed, the via holes have been miniaturized, and the IC package has been made smaller and more pinned. In addition, the passive elements of capacitors and resistors are also being miniaturized, integrated, and surface-mounted.

In particular, a technique for directly mounting an electronic component on the surface or inside of a printed wiring board or the like can not only achieve high-density mounting but also contribute to improvement in reliability. From these facts, the dimensional accuracy of the printed wiring board, that is, the accuracy of the wiring pitch is also required to be high, and the printed wiring board is also required to have thermal stability of dimensions.

As the printed wiring board, a plastic wiring board in which a metal layer or the like is arranged on the surface of a plastic film is generally used. The following two typical manufacturing methods are known as manufacturing methods for plastic wiring boards.

As a first method, there is a method of laminating a metal foil and a plastic film used for a conductor forming a circuit by a thermocompression bonding (lamination) method.

As a second method, a thin metal seed layer and a first metal layer are formed on a plastic film by a dry plating method such as a sputtering method, an ion plating method, or a vacuum deposition method, and electroless plating is performed on the thin metal seed layer and the first metal layer. A metallizing method for further forming a second metal layer by a method or a wet plating method of an electrolytic plating method can be mentioned.

Specific examples of the method for manufacturing a plastic wiring board by the metallizing method are disclosed in Patent Document 1 and Patent Document 2.

For example, in Patent Document 1, a metal seed layer made of nickel, chromium, or an alloy thereof is formed on a thermoplastic liquid crystal polymer film by a sputtering method, and then a copper conductive layer is formed by a sputtering method. Further, an example in which an electrolytic copper plating or a non-electrolytic copper plating or a combination of both is formed on a copper conductive layer formed by a sputtering method is disclosed.
By the way, in order to mount electronic components and the like at high density, the plastic wiring board may be required to be a double-sided metal laminate in which metal layers are arranged on both sides of a plastic film.

For example, Patent Document 3 discloses a double-sided metal-clad laminate in which metal sheets are bonded to both surfaces of a thermoplastic liquid crystal polymer film.

The double-sided metal laminate can also be manufactured by a metallizing method.

By the way, a single-sided metal laminate in which a metal laminate is provided on only one side of a plastic film has also been conventionally used. In a single-sided metal laminate, a metal seed layer and a metal layer are provided on one surface of a plastic film, and the metal layer is composed of a first metal layer and a second metal layer. Since the metal seed layer and the first metal layer are usually formed by a dry plating method, the plastic film is heated in a vacuum to make it water-free and covered with the metal seed layer or the first metal layer. ..

However, the moisture absorption of the plastic film progresses from the other surface of the plastic film on which the metal seed layer or the like is not provided, and the water content of the plastic film reaches an equilibrium state. Further, since the stage where the first metal layer is formed is before the second metal layer is provided, moisture absorption and expansion can be performed with almost no dimensional change being suppressed.

Therefore, after that, a second metal layer is formed on the first metal layer, the metal laminate is patterned, and even if a part of the plastic film is exposed, rapid moisture absorption by the plastic film and accompanying expansion hardly occur. , The dimensional change rate could be suppressed within the range of about ± 0.02% at the origin.

The origin means a case where the dimensional change does not occur even if the metal laminate is patterned, that is, a case where the water content of the plastic film is saturated when the metal laminate is patterned.

On the other hand, when manufacturing a double-sided metal laminate in which a metal laminate is arranged on both sides of a plastic film, usually, when forming a metal seed layer or a first metal layer, the plastic film is heated in a vacuum to obtain moisture. Both sides will be covered with a metal seed layer or a first metal layer. If both sides of the plastic film are covered with a metal seed layer or the like, the plastic film can hardly absorb moisture or the like. Therefore, the plastic film sandwiched between the metal seed layers or the like remains almost completely dry until patterning is performed. Has been done.

Then, after the second metal layer is formed, when the metal laminate is patterned, a dimensional change (expansion) due to moisture absorption occurs, and the dimensional change rates are MD: Machine dimension (mechanical axis direction) and TD: transverse dimension (horizontal axis). Both directions) move significantly to the plus side.

As described above, when a large dimensional change occurs due to sudden moisture absorption, the formed wiring pattern may shift, which is a problem.

Therefore, in the conventional double-sided metal laminate, in order to supplement the above-mentioned dimensional change due to moisture absorption and achieve the same dimensional change rate as the single-sided metal laminate within ± 0.02% at the origin, a metal seed layer or the like The heating conditions, tension adjustment, widening, etc. were performed when the film was formed.

Japanese Unexamined Patent Publication No. 2005-297405 Japanese Unexamined Patent Publication No. 2009-026990 Japanese Unexamined Patent Publication No. 2006-137011

However, if the double-sided metal laminated plate is adjusted by heating or the like in the manufacturing process, fluctuation factors increase, so that it is difficult to keep the dimensional change rate small, and the wiring pattern may shift after the wiring pattern is formed. It was difficult to control this.

In view of the above problems of the prior art, in one aspect of the present invention, a double-sided metal capable of suppressing deviation of the wiring pattern when the metal laminate arranged on the surface of the plastic film is etched to form the wiring pattern. It is an object of the present invention to provide a laminated board.

In order to solve the above problems, in one aspect of the present invention,
With plastic film
A metal seed layer placed directly on both sides of the plastic film,
A double-sided metal laminate having a metal layer arranged on the metal seed layer.
The center value of the dimensional change rate in IPC-TM-650, 2.2.4, and Metal C is in the range of 0.00% or more and 0.06% or less for MD and 0.04% or more and 0.10% or less for TD. , and the tolerance of the dimensional change rate, MD, within 0.02% ±, TD provides a double-sided metal laminate is within 0.01% ±.

According to one aspect of the present invention, there is provided a double-sided metal laminate capable of suppressing deviation of the wiring pattern when the metal laminate arranged on the surface of the plastic film is etched to form a wiring pattern. Can be done.

Explanatory drawing of the center value which took into account the elongation at the time of patterning and the change due to the tension in the process. The cross-sectional schematic diagram of the double-sided metal laminated board which concerns on embodiment of this invention. Explanatory drawing of the structural example of the film forming apparatus using the dry plating method. The explanatory view of the structural example of the continuous electrolytic plating apparatus.

Hereinafter, an embodiment of the double-sided metal laminate, the method for producing the double-sided metal laminate, and the pattern image transfer method of the present invention will be described.
[Double-sided metal laminate]
The double-sided metal laminate of the present embodiment can have a plastic film, a metal seed layer directly arranged on both sides of the plastic film, and a metal layer arranged on the metal seed layer.

Further, the tolerance of the dimensional change rate in IPC-TM-650, 2.2.4 and Method C can be set to ± 0.02% or less for MD and ± 0.01% or less for TD.

The inventor of the present invention has diligently studied a double-sided metal laminate that suppresses deviation of the wiring pattern when the metal laminate arranged on the surface of the plastic film is etched to form a wiring pattern. ..

Then, they have found that it is possible to suppress the occurrence of deviation in the wiring pattern when the wiring pattern is formed by suppressing the tolerance from the reference center value, and completed the present invention.

When trying to suppress the dimensional change rate from the origin when a wiring pattern is formed like the conventional double-sided metal laminate described above, it is necessary to adjust the heating conditions in the manufacturing process, which increases fluctuation factors. Therefore, the variation in the dimensional change rate is large. Therefore, when the wiring pattern is formed, the wiring pattern may be displaced. The origin means that the dimensional change does not occur even if the metal laminate is patterned as described above, that is, the water content of the plastic film is saturated when the metal laminate is patterned. ..

On the other hand, in the double-sided metal laminate of the present embodiment, the tolerance of the dimensional change rate, that is, the error of the dimensional change rate from the reference center value is suppressed to be small. According to the study of the inventor of the present invention, the deviation between the above-mentioned origin and the reference center value is, for example, by correcting the pattern transfer conditions using a photomask when forming the wiring pattern. It can be resolved. Therefore, it is not always necessary to match the center value with the origin, and it has been conventionally performed by defining the center value independently by taking into account the elongation due to the ambient humidity and the change due to the tension in the process when patterning. It is possible to eliminate variations in the dimensional change rate due to adjustment of heating conditions to bring it closer to the origin and widening.

Then, by reducing the tolerance of the dimensional change rate, which is an error from the reference center value, and correcting the pattern transfer conditions using a photomask according to the center value, the metal is used to form the wiring pattern. It is possible to prevent the wiring pattern from being displaced when the laminate is etched. In particular, it is possible to cope with the fine pitching (fine patterning) of the wiring pattern required in recent years.

Specifically, as shown in FIG. 1, for example, when patterning a plastic film during a manufacturing process, the conditions from point A in an absolutely dry state at 23 ° C. and 55% relative humidity for about 24 hours. When moisture is absorbed underneath, both MD and TD extend to point B at + 0.07%. Then, starting from point B, the change due to tension in the manufacturing process of the double-sided metal laminate is taken into consideration, the center value C is defined, and the tolerance of the dimensional change rate, that is, the center value C is used as a reference. The error of the dimensional change rate from the standard is within ± 0.02% for MD and within ± 0.01% for TD.

By using a double-sided metal laminate having a tolerance from the center value within a predetermined range as described above, it is possible to eliminate fluctuation factors such as adjustment of heating conditions for bringing the center value closer to the above-mentioned origin and widening. .. As a result, the only remaining fluctuation factors are the control fluctuation in the manufacturing process and the characteristic tolerance of the plastic film, and the dimensional change rate can be achieved within ± 0.02%, which is the center value set as a reference.

In terms of control fluctuations in the manufacturing process, it is difficult to control the tension of the single-sided metal laminated plate because the plastic film absorbs moisture and stretches in the manufacturing process. On the other hand, since the double-sided metal laminate hardly absorbs moisture in the manufacturing process, the tension control of the double-sided metal laminate is more advantageous, and according to the double-sided metal laminate of the present embodiment, the wiring pattern is displaced as compared with the single-sided metal laminate. It is possible to make a product with little variation in the occurrence of the above.

A configuration example of the double-sided metal laminated plate of the present embodiment will be specifically described below.

The double-sided metal laminate of the present embodiment can have a plastic film, a metal seed layer directly arranged on both sides of the plastic film, and a metal layer arranged on the metal seed layer. The metal layer can have, for example, a first metal layer and a second metal layer arranged on the first metal layer. Further, the metal layer can also be composed of the first metal layer and the second metal layer.

In the double-sided metal laminate of the present embodiment, the tolerance of the dimensional change rate of MD and TD by IPC-TM-650, 2.2.4, and Method C is within ± 0.02% for MD and ± for TD. It can be within 0.01%.

Here, first, the structure of the double-sided metal laminated plate of the present embodiment will be described with reference to FIG. FIG. 2 schematically shows a cross-sectional view of the double-sided metal laminated plate 10 on a plane perpendicular to the main surface of the plastic film 11.

In the double-sided metal laminated plate 10, the metal seed layer 12A, the first metal layer 13A, and the second metal layer 14A are laminated in this order on one surface 11a of the plastic film 11 from the plastic film 11 side. Further, on the other surface 11b of the plastic film 11, the metal seed layer 12B, the first metal layer 13B, and the second metal layer 14B are laminated in this order from the plastic film 11 side.

That is, it has a structure in which the metal seed layers 12A and 12B, the first metal layers 13A and 13B, and the second metal layers 14A and 14B are laminated in this order on both surfaces (both main surfaces) of the plastic film 11.

The metal seed layers 12A and 12B are directly arranged on both sides of the plastic film 11. That is, they are arranged without using an adhesive or the like. Further, the adhesive is also provided between the layers, that is, between the metal seed layers 12A and 12B and the first metal layers 13A and 13B, and between the first metal layers 13A and 13B and the second metal layers 14A and 14B. It can be configured to come into direct contact without the intervention of such means.

Subsequently, each member will be described.
(Plastic film)
First, the details of the plastic film will be described below.

The material of the plastic film is not particularly limited, and a film formed of various plastic materials can be used.

Examples of the plastic film material include heat-resistant resins such as polyimide and polyethylene terephthalate, polyamide resins, polyester resins, polytetrafluoroethylene resins, polyphenylene sulfide resins, polyethylene naphthalate resins, and liquid crystal polymer resins. One or more resins selected from the above can be used.

As the material of the plastic film, a material in which two or more kinds of resins are mixed can also be used.

As the material of the plastic film, it is preferable to use a polyimide resin because it has excellent heat resistance and insulating properties. That is, the plastic film is preferably a polyimide film made of polyimide.

Polyimide has a structure represented by the chemical formula (1). In the chemical formula (1), the case where R and R'are aromatic is called aromatic polyimide, and is widely used industrially. Aromatic polyimide is generally obtained by a polycondensation reaction of an aromatic acid anhydride and a diamine. Therefore, polyimides having various structures can be obtained by combining the acid component and the diamine component, and physical properties such as heat resistance may differ depending on the chemical (molecular) structure. However, when polyimide is used as the material for the plastic film of the double-sided metal laminate of the present embodiment, the structure of the polyimide is not particularly limited, and polyimides having various structures can be used.

例えば、化学式（２）、又は化学式（３）で表される構造を有するポリイミドを、プラスチックフィルムの材料として用いることができる。

For example, a polyimide having a structure represented by the chemical formula (2) or the chemical formula (3) can be used as a material for a plastic film.

The chemical formula (2) is that the acid component pyromellitic dianhydride (PMDA) and the diamine component 4,4'-diaminodiphenyl ether (also known as 4,4'-oxybisbenzeneamine, 4,4'-oxydi Aniline = ODA) can be produced by polymerizing in an organic solvent.

化学式（３）は、酸成分としてビフェニルテトラカルボン酸二無水物（ＢＰＤＡ）を使用しており、ベンゼン環とイミド結合のみの分子構造を有している。このＢＰＤＡを酸成分に用いることで、ＰＭＤＡを用いた化学式（２）の構造を有するポリイミドと比べて、より剛直な構造になっている等、特性に違いが見られる。

The chemical formula (3) uses biphenyltetracarboxylic dianhydride (BPDA) as an acid component, and has a molecular structure of only a benzene ring and an imide bond. By using this BPDA as an acid component, there are differences in characteristics such as a more rigid structure as compared with the polyimide having the structure of the chemical formula (2) using PMDA.

化学式（３）の様に、イミド結合により直接結合された芳香族環は共役構造を取るため、上述の様に剛直で強固な構造をもつ。また、芳香族環が同一平面に配列して分子鎖が互いに密に充填（パッキング）され、極性の高いイミド結合が強い分子間力を有することから、分子鎖間の結合力も強固となる。

As shown in the chemical formula (3), the aromatic ring directly bonded by the imide bond has a conjugated structure, and therefore has a rigid and strong structure as described above. Further, since the aromatic rings are arranged in the same plane and the molecular chains are tightly packed with each other and the highly polar imide bond has a strong intermolecular force, the bonding force between the molecular chains is also strong.

When a polyimide film is used as the plastic film, a commercially available polyimide film can also be used. For example, the Kapton (registered trademark) series manufactured by Toray DuPont Co., Ltd. and the Upirex (registered) manufactured by Ube Industries, Ltd. A trademark) series or the like can also be used.

The thickness of the plastic film is not particularly limited, but is preferably 5 μm or more, and more preferably 10 μm or more, for example. The upper limit of the thickness of the plastic film is not particularly limited, but if it becomes excessively thick, the handleability of the double-sided metal laminated plate may deteriorate. Therefore, for example, it is preferably 80 μm or less. The thickness of the plastic film is particularly preferably 25 μm or more and 38 μm or less.
(Metal seed layer)
Next, the metal seed layer will be described in detail below.

The metal seed layer has, for example, a function of enhancing the adhesion between the plastic film and the first metal layer.

The material of the metal seed layer is also not particularly limited, but from the viewpoint of enhancing the adhesion to the first metal layer, for example, it is preferable to use a metal material. Examples of the material of the metal seed layer include nickel, chromium, molybdenum, titanium, vanadium, tin, gold, silver, zinc, palladium, ruthenium, rhodium, iron, aluminum, lead, carbon, and lead-tin solder alloys. It is preferable that the metal or alloy contains one or more of these metals. In particular, the material of the metal seed layer is more preferably one selected from nickel, chromium, an alloy containing nickel, an alloy containing chromium, and an alloy containing nickel and chromium, and an alloy containing nickel and chromium, for example, It is more preferably a Ni—Cr alloy. That is, it is more preferable that the metal seed layer is a layer made of a Ni—Cr alloy. Even when the metal seed layer is a layer made of a Ni—Cr alloy, it does not exclude, for example, the inclusion of unavoidable components mixed in the manufacturing process.

The thickness of the metal seed layer is not particularly limited, but is preferably 2 nm or more and 50 nm or less, for example. This is because when the thickness of the metal seed layer is less than 2 nm, it is eroded by the etching solution when patterning is performed to form wiring or the like, and the etching solution soaks between the metal seed layer and the plastic film, so that the wiring is formed. This is because it may float. On the other hand, if the thickness of the metal seed layer exceeds 50 nm, the metal seed layer of the portion to be removed cannot be completely removed by etching when patterning is performed to form wiring or the like, and the metal seed layer remains between the wirings as a residue and is insulated. This is because there is a risk of causing defects. The thickness of the metal seed layer is particularly preferably 2 nm or more and 30 nm or less.
(Metal layer)
Next, the details of the metal layer will be described below.

Since the metal layer can have a first metal layer and a second metal layer as described above, the first metal layer and the second metal layer will be described below.

The materials of the first metal layer and the second metal layer are not particularly limited, and a material having an electric conductivity suitable for the intended use can be selected. For example, the materials of the first metal layer and the second metal layer may be selected. , Copper and a copper alloy with at least one metal selected from nickel, molybdenum, tantalum, titanium, vanadium, chromium, iron, manganese, cobalt and tungsten, or a material containing copper. Further, the first metal layer and the second metal layer may be copper layers composed of copper.

The first metal layer and the second metal layer may be made of the same material or may be made of different materials.

In particular, since copper is generally used as a material for wiring boards, it is preferable that the first metal layer and the second metal layer are a layer made of copper, that is, a copper layer. Even when the first metal layer and the second metal layer are layers made of copper, it does not exclude, for example, the inclusion of unavoidable components mixed in the manufacturing process.

The thicknesses of the first metal layer and the second metal layer are not particularly limited, and for example, the amount of current supplied to the double-sided metal laminated plate of the present embodiment and the double-sided metal laminated plate are processed. It can be arbitrarily selected according to the conditions and the like. For example, the total of the thickness of the first metal layer and the thickness of the second metal layer is preferably 0.1 μm or more and 20 μm or less.

Examples of the method for forming the wiring using the double-sided metal laminated plate of the present embodiment include a subtractive method and a semi-additive method. For example, when wiring is formed by the semi-additive method, the first metal layer and the second metal layer are selectively grown and the wiring is processed.

Then, by setting the total thickness of the first metal layer and the thickness of the second metal layer to 0.1 μm or more, for example, when wiring is formed on the double-sided metal laminated plate of the present embodiment to form a wiring substrate. This is because a sufficient current can be supplied to the first metal layer and the second metal layer constituting the wiring.
On the other hand, by setting the total thickness of the first metal layer and the thickness of the second metal layer to 20 μm or less, it is possible to maintain sufficiently high production even when wiring is processed by etching, and as a wiring board. This is because the total thickness of the above can be sufficiently suppressed, which is preferable.

The total of the thickness of the first metal layer and the thickness of the second metal layer is more preferably 0.4 μm or more and 2.0 μm or less.

Since the metal layer can also be composed of a first metal layer and a second metal layer, the thickness of the metal layer is, for example, the above-mentioned thickness of the first metal layer and the thickness of the second metal layer. It is preferable that the total of the above is in a suitable range.

The thickness of the first metal layer alone is not particularly limited, but is preferably 10 nm or more and 300 nm or less, for example. As will be described later, the second metal layer can be formed by, for example, a wet plating method, but by setting the thickness of the first metal layer to 10 nm or more, a sufficient power supply amount can be secured and it is uniform. This is because the second metal layer can be formed. Further, from the viewpoint of productivity, the thickness of the first metal layer is preferably 300 nm or less.

Further, it is preferable that the total thickness of the metal seed layer and the first metal layer described above is 350 nm or less. By setting the total thickness of the metal seed layer and the first metal layer to 350 nm or less, it is possible to secure a sufficient supply amount when, for example, the second metal layer is formed by the electrolytic plating method. Because. Further, it is possible to particularly improve the adhesion of the second metal layer to the plastic film.

The lower limit of the total thickness of the metal seed layer and the first metal layer is not particularly limited, but is preferably 12 nm or more, for example.

The details of the IPC standard will be described below.

The double-sided metal laminate of the present embodiment has the tolerance of the dimensional change rate of MD and TD by IPC-TM-650, 2.2.4, and Method C described above, MD is within ± 0.02%, and TD is. It can be within ± 0.01%.

For evaluation of the dimensional change rate (dimensional stability) of flexible derivative materials such as metal laminates, refer to Section 2.2: Dimensional Inspection Method No. in the IPC-TM-650: Test Method Manual. Follow 22.4.

IPC (Institute for Interconnecting and Packaging Electronic Circuits) refers to "institutes that connect electronics" and establishes quality standards in business processes in the manufacturing industry. In Europe, the United States and Asia, the IPC standard has been adopted by many manufacturers such as the electronic equipment industry, printed circuit board designers / manufacturers, and electronic equipment manufacturers, and the above IPC-TM-650 is a standard defined by the IPC. It is one of.

The dimensional change rate of MD and TD by IPC-TM-650, 2.2.4, Method C is the No. of IPC-TM-650, which is the IPC standard. It means the dimensional change rate of MD and TD evaluated by the test method of Method C disclosed in 2.2.4 (Revision C).

As described above, MD means Machine dimension (machine axis direction) and means the longitudinal direction of the double-sided metal laminate. Further, TD means a transverse dimension (horizontal axis direction), and means a direction orthogonal to MD.

Further, in the index of dimensional change rate, shrinkage is represented by a negative value and elongation is represented by a positive value.

Then, according to the above Method C, it is possible to evaluate the dimensional change rate after etching the metal laminate and further heat-treating it at 150 ° C. for 30 minutes.

Here, regarding the double-sided metal laminate of the present embodiment, the IPC-TM-650: Test Method Manual, Section 2.2: Dimensional Inspection Method No. The procedure for evaluating the dimensional change rate according to Method C of 2.2.4 will be described. Specifically, the measurement can be performed according to the following procedures (a) to (c), and the dimensional change rate can be calculated from the measurement result.
(A) The double-sided metal laminate to be evaluated is humidity-controlled for 24 hours at 23 ° C. and a relative humidity of 55%, and the initial dimension (I) is measured.
(B) Then, after removing a part of the metal laminate by etching, the humidity is adjusted at 23 ° C. and a relative humidity of 55% for 24 hours.
(C) Next, after heating at 150 ° C. for 30 minutes, the humidity is adjusted at 23 ° C. and a relative humidity of 55% for 24 hours to measure the dimensions (A).

The dimensional change rate of Method C is calculated by (dimensional change rate) = (AI) / I (%). The dimensional measurement is performed at two points, and the average value of the dimensional change rates at the two points is the dimensional change rate of Method C.

In the double-sided metal laminate of the present embodiment, the tolerance of the dimensional change rate in IPC-TM-650, 2.2.4, and Method C is within ± 0.02% for MD and ± 0.01 for TD. It can be within%.

IPC-TM-650, 2.2.4. As described above, Method C performs heating at 150 ° C. and humidity control in an environment with a relative humidity of 55%.

Generally, a double-sided metal laminate is placed in an environment with a relative humidity of about 55% at the time of patterning or after patterning, and is in the same environment as in the case of Method C. Further, by performing the heat treatment, it is possible to remove the change due to the tension contained in the double-sided laminated metal plate in the manufacturing process.

Therefore, IPC-TM-650, 2.2.4. By setting the tolerance of the dimensional change rates of MD and TD in Method C within the above range, when a wiring pattern is formed based on the center value of the tolerance, it is possible to suppress the deviation of the wiring after the wiring pattern is formed. Becomes possible.

The center value of the dimensional change rate is not particularly limited, but if it is excessively deviated from the origin, it becomes difficult to sufficiently cope with it only by correcting the transfer conditions of the pattern using a photomask. In some cases. Therefore, in the double-sided metal laminate of the present embodiment, the center value of the dimensional change rate of MD and TD in IPC-TM-650, 2.2.4, and Method C is 0.00% or more and 0.06 in MD. % Or less, and TD is preferably in the range of 0.04% or more and 0.10% or less.

The median value of the dimensional change rate of the double-sided metal laminate can be calculated based on the moisture absorption conditions due to the atmosphere when patterning the metal laminate, the tension applied to the double-sided metal laminate in the manufacturing process, and the like. .. Therefore, the center value of the dimensional change rate of MD and TD in IPC-TM-650, 2.2.4, and Method C is assumed based on the atmosphere at the time of patterning and the manufacturing conditions of the double-sided metal laminated plate. , It can be said that it is the center value of the calculated dimensional change rate of MD and TD.

Specifically, for example, the center value was added to the double-sided metal laminate during the manufacturing process, as well as the elongation when the metal laminate was patterned and the humidity was adjusted at 23 ° C. and a relative humidity of 55% for 24 hours. It can be calculated by taking into account the change due to tension.

According to the double-sided metal laminated plate of the present embodiment described so far, the center value is determined in consideration of the dimensional change rate when patterning is performed, and the tolerance from the center value is suppressed. Therefore, when the metal laminate arranged on the surface of the plastic film is etched to form the wiring pattern, it is possible to suppress the occurrence of deviation or disconnection in the wiring pattern.
[Manufacturing method of double-sided metal laminate]
A configuration example of the method for manufacturing the double-sided metal laminated plate in the present embodiment will be described.

The double-sided metal laminated board described above can be manufactured by the method for manufacturing the double-sided metal laminated board in the present embodiment. Therefore, when the double-sided metal laminated plate is described, some of the above-mentioned matters will be omitted.

Regarding the method for manufacturing a double-sided metal laminated plate in the present embodiment, one configuration example can have the following steps.

A metal seed layer forming step of forming a metal seed layer on both sides of a plastic film by a dry plating method.
A metal layer forming step of forming a metal layer on a metal seed layer.
The median values of the dimensional change rates of MD and TD in IPC-TM-650, 2.2.4, and Method C are 0.00% or more and 0.06% or less for MD, and 0.04% or more and 0 for TD. It can be in the range of 10% or less. Further, the tolerance of the dimensional change rate can be within ± 0.02% for MD and within ± 0.01% for TD.

The metal layer forming step can include, for example, the following steps.

A first metal layer forming step of forming a first metal layer on a metal seed layer by a dry plating method.
A second metal layer forming step of forming a second metal layer on the first metal layer by a wet plating method.
Hereinafter, each step will be described.

In the metal seed layer forming step, the metal seed layer can be formed on the surface of the plastic film. The method for forming the metal seed layer is not particularly limited, but for example, it is preferable to use a dry plating method such as a vapor deposition method or a sputtering method. As a method for forming the metal seed layer, it is more preferable to use a sputtering method because the film thickness can be easily controlled. In the metal seed layer forming step, the specific conditions for forming the metal seed layer are not particularly limited, and are arbitrarily selected according to the material of the metal seed layer, the performance required for the metal seed layer, and the like. can do.

In the metal seed layer forming step, the metal seed layer can be formed on both sides of the plastic film at the same time.

As described above, the metal layer forming step can include, for example, a first metal layer forming step and a second metal layer forming step. Therefore, each of the first metal layer forming step and the second metal layer forming step will be described below.

In the first metal layer forming step, the first metal layer can be formed on the metal seed layer. The method for forming the first metal layer is also not particularly limited, but it is preferable to use a dry plating method such as a vapor deposition method or a sputtering method. As a method for forming the first metal layer, it is more preferable to use a sputtering method because the film thickness can be easily controlled.

In the first metal layer forming step, the specific conditions for forming the first metal layer are not particularly limited, and depend on the material of the first metal layer, the performance required for the first metal layer, and the like. Can be selected arbitrarily.

In the first metal layer forming step, the first metal layer can be simultaneously formed on the metal seed layers formed on both sides of the plastic film.

Here, a configuration example of a film forming apparatus using a dry plating method, which can be suitably used when forming a metal seed layer or a first metal layer, will be described with reference to FIG.

FIG. 3 is a diagram schematically showing the configuration of the film forming apparatus 30.

The film forming apparatus 30 of FIG. 3 is an apparatus for forming a film by a sputtering method, and is also referred to as a sputtering film coater. As will be described later, by changing the configurations of the magnetron sputtering cathodes 37a to 37d, it is possible to obtain a film forming apparatus using or using a film forming method other than the sputtering method.

The film forming apparatus 30 holds the film to be continuously conveyed by the roll-to-roll method in the decompression container on the holding surface of the can roll 32 as the holding means, that is, the outer peripheral surface. The film-forming particles discharged from the film-forming means toward the film-forming material can be deposited on the surface of the film-deposited object to form a film.

A cooling means (not shown) can be provided inside the can roll 32, and even in a dry plating method in which a heat load is applied, the film is continuously formed without causing thermal damage. Can be processed.

Each element constituting the film forming apparatus 30, and the film forming procedure of the metal seed layer, the first metal layer, and the like will be specifically described.

A take-up roll 331 and a take-up roll 332 are provided in the chamber 31 as a decompression container, and a film-deposited film is formed between the take-up roll 331 and the take-up roll 332 by a roll-to-roll method. Can be transported. The shape and material of the chamber 31 are not particularly limited as long as they can withstand a reduced pressure state, and various chambers can be used.

The transport path of the plastic film F will be described. First, a long plastic film F, which is a film to be formed, is supplied from the unwinding roll 331. When only the first metal layer is formed, the long plastic film F may have a metal seed layer formed on one or both surfaces of the plastic film.

Then, in the transport path of the film to be filmed from the unwinding roll 331 to the can roll 32, for example, a free roll 341 for guiding the plastic film F, a tension sensor roll 351 for measuring the tension of the plastic film F, and a tension The motor-driven feed roll 361, which introduces the plastic film F sent out from the sensor roll 351 into the can roll 32, can be arranged in this order.

Further, in the transport path from the can roll 32 to the take-up roll 332, which winds up the plastic film F, the motor-driven feed roll 362 and the tension sensor roll 352 for measuring the tension of the plastic film F are also used. , And the free roll 342 that guides the plastic film F can be arranged in this order.

It is preferable that the feed rolls 361 and 362 provided in the vicinity of the can roll 32 are rotationally driven by a motor so that the peripheral speed of the can roll 32 can be adjusted. Further, the unwinding roll 331 can be configured to maintain the tension balance of the plastic film F by using torque control by a powder clutch or the like. With this configuration, the plastic film F unwound while adjusting the tension is cooled by the feed rolls 361 and 362, which rotate in conjunction with the can roll 32, in close contact with the outer peripheral surface of the can roll 32. However, it is subjected to a dry plating process and can be wound by a motor-driven winding roll 332.

Plate-shaped magnetron sputtering cathodes 37a to 37d, which are film forming means, are arranged along the transport path of the plastic film F at positions facing the outer peripheral surface of the can roll 32. As a result, the surface of the conveyed plastic film F can be subjected to a sputtering film formation process, which is a dry plating process.

The dry plating process performed by the film forming apparatus 30 is not limited to the above sputtering method. The sputtering method can be used in combination with other vacuum film forming methods such as CVD (chemical vapor deposition), ion plating, and vacuum vapor deposition. Further, instead of the sputtering method, the above-mentioned other vacuum film forming method can also be used. When these other vacuum film forming methods are used, a predetermined vacuum film forming means can be provided in place of a part or all of the magnetron sputtering cathodes 37a to 37d.

In addition to the above-mentioned means, various means (not shown) can be arbitrarily connected to the chamber 31. For example, various atmosphere control means such as an exhaust means such as a dry pump, a turbo molecular pump, and a cryocoil, and a gas supply means for supplying gas into the chamber 31 can be connected. Further, for example, a heater (not shown) or the like may be installed along the transport path of the plastic film so that the moisture of the plastic film supplied from the unwinding roll 331 can be removed.

As described above, both the metal seed layer and the first metal layer can be suitably formed by the dry plating method.

Therefore, for example, the first metal layer can be continuously processed, that is, continuously formed in a vacuum chamber in which the metal seed layer is formed.

A configuration example in the case of continuously forming the metal seed layer and the first metal layer by using the above-mentioned film forming apparatus 30 will be described.

First, the plastic film is attached to the unwinding roll 331.

Further, for example, a target for a metal seed layer having a composition corresponding to the metal seed layer is attached to the magnetron sputtering cathode 37a, and a target for the first metal layer having a composition corresponding to the first metal layer is attached to the magnetron sputtering cathodes 37b to 37d. To wear.

Next, the inside of the chamber 31 is exhausted by an exhaust means (not shown), the inside of the chamber 31 is ^{depressurized to an ultimate pressure of about 10 -4} Pa, and then a sputtering gas is introduced by a gas supply means (not shown) to inside the chamber 31 at 0.1 Pa. Adjust the pressure to about 10 Pa or less. As the sputtering gas, an inert gas such as argon can be preferably used, and a gas such as oxygen can be further added depending on the purpose.

Then, the metal seed layer and the first metal layer can be laminated on the plastic film by applying a voltage to the magnetron sputtering cathodes 37a to 37d while supplying the plastic film from the unwinding roll 331.

After forming the first metal layer, it is possible to have a second metal layer forming step of forming the second metal layer on the first metal layer by a wet plating method as described above.

In the second metal layer forming step, it is preferable to simultaneously form the second metal layer on both sides of the plastic film from the viewpoint of productivity. That is, it is preferable to simultaneously form the second metal layer on the first metal layer formed on one surface of the plastic film and on the first metal layer formed on the other surface of the plastic film.

In the second metal layer forming step, the specific conditions for forming the second metal layer by the wet plating method are not particularly limited, and the plating selected according to the material or the like constituting the second metal layer is used. A liquid can be used to form a film, for example, by an electrolytic plating method or a electroless plating method.

When the second metal layer is formed by the electrolytic plating method, for example, the continuous electrolytic plating apparatus 40 shown in FIG. 4 can be used. Note that FIG. 4 shows a configuration example of a continuous electrolytic plating apparatus capable of simultaneously forming a second metal layer on both sides of a plastic film.

FIG. 4 shows a cross-sectional view of the continuous electrolytic plating apparatus 40 on a plane parallel to the transport direction of the double-sided metal laminated precursor plate F1.

In the continuous electrolytic plating apparatus 40, the unwinding roll 41 for unwinding the double-sided metal laminated precursor plate F1, which is a plastic film in which the metal seed layer and the first metal layer are arranged on both sides in this order, and the plating solution are used. Conveying direction of the filled plating solution tank 42, the anodes 43a to 43p arranged parallel to each other inside the plating solution tank 42, and the double-sided metal laminated precursor plate F1 inside the plating solution tank 42. The dipping rolls 44a to 44d for upside down, the power feeding rolls 45a to 45e outside the plating solution tank 42 for supplying power to the double-sided metal laminated precursor plate F1, and the double-sided metal laminated precursor plate F1 are electroplated. The winding roll 46 for winding the double-sided metal laminated plate F2 obtained by applying the above method is provided.

The unwinding roll 41, the dipping rolls 44a to 44d, the feeding rolls 45a to 45e, and the winding roll 46 constitute a means for transporting the double-sided metal laminated precursor plate F1, thereby forming the double-sided metal laminated precursor plate F1. While keeping the width direction horizontal, it can be conveyed in the longitudinal direction by a roll-to-roll method and immersed in the plating solution a plurality of times.

The feeding roll and the anode located in the vicinity thereof form an electrical pair. Specifically, between the feeding roll 45a and the anodes 43a and 43b, between the feeding roll 45b and the anodes 43c to 43f, between the feeding roll 45c and the anodes 43g to 43j, the feeding roll 45d and the anodes 43k to 43n. The feeding roll 45e and the anodes 43o and 43p form a pair with each other. Each pair receives power from an independent power source (not shown), with separate current controls between the different pairs.

The anodes (anodes) 43a to 43p are not particularly limited and can be arbitrarily selected depending on the plating solution to be used, and for example, a soluble anode or an insoluble anode can be used. The plating solution to be put into the plating solution tank 42 can be arbitrarily selected according to the composition of the second metal layer. For example, various copper plating solutions, more specifically, for example, a copper sulfate plating bath (glossy bath). ) Etc. can be used.

When a copper sulfate plating solution is used as the plating solution, the copper sulfate plating solution can contain copper sulfate, sulfuric acid, a trace amount of chlorine ions, various additives, and the like, and the composition thereof can be appropriately selected according to the purpose. it can. When a copper sulfate plating solution is used as the plating solution, copper ions in the plating solution can be reduced to easily form a copper layer having a desired thickness on the metal seed layer of the double-sided metal laminated precursor plate F1. it can.

In the method for manufacturing the double-sided metal laminated plate of the present embodiment described above, the heating conditions and the tension adjustment / widening for the center value of the dimensional change rate as the origin are not implemented. Therefore, when the metal laminate of the obtained double-sided metal laminate is etched to form the wiring pattern, it is possible to prevent the wiring pattern from being displaced.

Further, the method for manufacturing a double-sided metal laminate according to the present embodiment may further include a step for forming a wiring pattern on the double-sided metal laminate. In this case, for example, the following steps can be further provided. By carrying out the following steps, a double-sided metal laminated board having a wiring pattern, that is, a wiring board can be obtained, which can be said to be a method for manufacturing a wiring board.

A resist layer forming step of forming a resist layer on a metal layer.
A pattern transfer step in which a pattern is transferred to a resist layer using a photomask.
In the pattern transfer step, the pattern transfer conditions are based on the center values of the dimensional change rates of MD and TD in IPC-TM-650, 2.2.4, and Method C of the double-sided metal laminate before the resist layer forming step. Can be corrected.

As will be described below, the resist layer forming step can be rephrased as a step of forming a resist layer on the first metal layer or the second metal layer.

When the metal laminate of the double-sided metal laminate is patterned to form a double-sided metal laminate having a wiring pattern, that is, a double-sided wiring board is used, for example, the subtractive method or the semi-additive method is used to form the wiring pattern. Can be used.

The subtractive method is a method of chemically etching and removing unnecessary portions not included in the wiring pattern of a metal laminate including a metal seed layer, a first metal layer, and a second metal layer.

The semi-additive method is a method of selectively growing a plating film to form a circuit.

First, a case where a wiring pattern is formed by the subtractive method will be described as an example.

In the resist layer forming step, the resist layer can be formed on the metal layer, specifically, the second metal layer. Therefore, the resist layer forming step can be carried out after the second metal layer forming step of the method for manufacturing a double-sided metal laminate described above.

Then, in the pattern transfer step, the pattern can be transferred to the resist layer formed in the resist layer forming step by using a photomask.

As described above, in the double-sided metal laminate obtained by the method for producing the double-sided metal laminate of the present embodiment, the heating conditions for bringing the center value of the tolerance closer to the origin are adjusted in the manufacturing process. Absent. Therefore, in the double-sided metal laminated plate obtained by the method for manufacturing the double-sided metal laminated plate of the present embodiment, the center value of the dimensional change rate deviates from the origin. Therefore, in the above-mentioned pattern transfer step, the dimensional changes of MD and TD in IPC-TM-650, 2.2.4, and Method C of the double-sided metal laminated board (double-sided substrate laminated precursor board) before the resist layer forming step. It is preferable to correct the transfer conditions of the pattern based on the center value of the rate. By performing such correction, the metal laminate is patterned by the formed pattern, and the dimensional change of the plastic film is incorporated when a part of the plastic film is exposed, so that the formed wiring pattern is deviated. Can be suppressed.

The median value of the dimensional change rate of the double-sided metal laminate as a reference is calculated based on the moisture absorption conditions due to the atmosphere when patterning the metal laminate, the tension applied to the double-sided metal laminate in the manufacturing process, and the like. be able to. Therefore, the center value of the dimensional change rate of MD and TD in IPC-TM-650, 2.2.4, and Method C is assumed based on the atmosphere at the time of patterning and the manufacturing conditions of the double-sided metal laminated plate. It can be said that it is the center value of the dimensional change rate of MD and TD.

The content of the correction of the transfer condition of the pattern is not particularly limited, but when the wiring pattern is formed and the plastic film is exposed, the plastic film absorbs moisture and expands. It is more preferable to transfer the pattern. Specifically, it is more preferable that the pattern to be transferred is corrected, adjusted and transferred by assuming that the center value of the dimensional change rate of the double-sided metal laminated plate is on the minus side.

Specifically, for example, in the pattern transfer step, the center value of the dimensional change rate of the double-sided metal laminate when transferring using a photomask is -0.06% or more and 0.00% or less for MD, and-for TD. It is more preferable to correct the transfer condition of the pattern by regarding it as 0.10% or more and −0.04% or less. In this way, before etching, the actual center value of the dimensional change rate is assumed to be on the minus side of the calculated center value after etching, and the pattern is transferred, which is more appropriate when the wiring pattern is formed by etching. Wiring patterns can be arranged at various positions.

The method of correcting the pattern transfer condition is not particularly limited, but it can be performed by, for example, adjusting the position between the double-sided metal laminated plate and the photomask, the distance between the projection lens and the laminated plate, and selecting the mask to be used. it can.

In the pattern transfer step, after the pattern is transferred to the resist layer, a wiring pattern can be formed in the same manner as in a normal subtractive method. For example, it can have the following steps.

A developing process in which an unnecessary portion of the resist layer is removed to form a patterned resist layer.
An etching process in which an etching solution is supplied from the upper surface of the resist layer and chemical etching is performed to remove unnecessary parts of the metal laminate.
A cleaning process that cleans a double-sided metal laminate to remove residual etching solution.

Through the above steps, a double-sided metal laminate having a desired wiring pattern, that is, a wiring board can be formed.

Next, a case where a wiring pattern is formed by the semi-additive method will be described as an example.

In the resist layer forming step, the resist layer can be formed on the metal layer, specifically, the first metal layer or the second metal layer. Therefore, the resist layer forming step is carried out after the first metal layer forming step of the method for manufacturing a double-sided metal laminate described above, before the second metal layer forming step, or after the second metal layer forming step. be able to.

Then, in the pattern transfer step, the pattern can be transferred to the resist layer formed in the resist layer forming step by using a photomask.

In the pattern transfer step, the dimensions of the double-sided metal laminated precursor plate or the double-sided metal laminated plate IPC-TM-650, 2.2.4, MD and TD in Method C formed before the resist layer forming step. It is preferable to correct the transfer conditions of the pattern based on the center value of the rate of change.

Further, even in the subtractive method, as described above, the median value of the dimensional change rate of the double-sided metal laminated precursor plate or the double-sided metal laminated plate when transferring using a photomask is -0.06% or more 0 for MD. It is preferable to correct the transfer conditions of the pattern by assuming that it is 0.00% or less and TD is −0.10% or more and −0.04% or less.

The double-sided metal laminated precursor plate means a laminated plate in which a metal seed layer and a first metal layer are formed on both sides of a plastic film before the second metal layer is formed.

In the pattern transfer step, after the pattern is transferred to the resist layer, a wiring pattern can be formed in the same manner as in a normal semi-additive method. For example, it can have the following steps.

A developing process in which an unnecessary portion of the resist layer, that is, a portion forming a metal layer for wiring is removed to obtain a patterned resist layer.
A wiring metal layer forming step of forming a wiring metal layer on a metal layer, specifically, on a first metal layer or on a second metal layer, that is, at an opening of a resist layer.
A resist removing step of removing a resist layer after forming a metal layer for wiring.
An etching step of removing the exposed metal seed layer and the metal layer (first metal layer, or first metal layer and second metal layer) by removing the resist layer.
A cleaning process that cleans a double-sided metal laminate to remove residual etching solution.

As the metal layer for wiring, for example, the same material as the above-mentioned material can be used for the second metal layer, and the film can be formed by a wet plating method like the second metal layer. Then, for example, when a wiring metal layer is formed on the first metal layer, the wiring metal layer can be used as the second metal layer. Further, even when the wiring metal layer is formed on the second metal layer, the second metal layer and the wiring metal layer can be combined to form the second metal layer.

According to the method for manufacturing a double-sided metal laminated plate of the present embodiment described above, the center value is determined in consideration of the dimensional change rate when patterning is performed, and the tolerance from the center value is suppressed. Therefore, when the metal laminate arranged on the surface of the plastic film is etched to form the wiring pattern, it is possible to prevent the wiring pattern from being displaced.

The double-sided metal laminated plate obtained by the method for producing a double-sided metal laminated plate of the present embodiment can be suitably used in various applications in which dimensional change of a wiring board or the like for high-density mounting is particularly required to be suppressed. More specifically, for example, the double-sided metal laminate obtained by the method for manufacturing a double-sided metal laminate according to the present embodiment can be used as a material for a wiring board that joins electronic components, electrically connects them, and mechanically fixes them. , Very useful.
[Image transfer method of wiring pattern]
Next, the image transfer method of the wiring pattern of the present embodiment will be described.

The wiring pattern image transfer method of the present embodiment is a wiring pattern image transfer method, which is a plastic film, a metal seed layer directly arranged on both sides of the plastic film, and a metal arranged on the metal seed layer. A step of forming a resist layer on a metal layer of a double-sided metal laminate having a layer.
A pattern transfer step in which a pattern is transferred to a resist layer using a photomask.
Then, in the pattern transfer step, the pattern transfer conditions can be corrected based on the center values of the dimensional change rates of MD and TD in IPC-TM-650, 2.2.4, and Method C of the double-sided metal laminate. it can.

More specifically, for example, as a first configuration example of the image transfer method of the wiring pattern of the present embodiment, the following steps can be included.

An image transfer method of a wiring pattern, which comprises a plastic film, a metal seed layer directly arranged on both sides of the plastic film, and a first metal layer arranged on the metal seed layer.
A resist layer forming step of forming a resist layer on the second metal layer of a double-sided metal laminate having a second metal layer arranged on the first metal layer.
A pattern transfer step in which a pattern is transferred to a resist layer using a photomask.
Then, in the pattern transfer step, the pattern transfer conditions can be corrected based on the center values of the dimensional change rates of MD and TD in IPC-TM-650, 2.2.4, and Method C of the double-sided metal laminate. it can.

Further, as a second configuration example of the image transfer method of the wiring pattern of the present embodiment, the following steps can be included.

A double-sided metal lamination precursor comprising a plastic film, a metal seed layer directly arranged on both sides of the plastic film, and a first metal layer arranged on the metal seed layer, which is an image transfer method of a wiring pattern. A step of forming a resist layer on the first metal layer of a plate.
A pattern transfer step in which a pattern is transferred to a resist layer using a photomask.
Then, in the pattern transfer step, the pattern transfer conditions are corrected based on the center values of the dimensional change rates of MD and TD in IPC-TM-650, 2.2.4, and Method C of the double-sided metal laminated precursor plate. be able to.

The first configuration example of the image transfer method of the wiring pattern of the present embodiment is a subtractive method of the method for manufacturing a double-sided metal laminate described above, or a semi-additive method in which a resist layer is formed on a second metal layer. It can be carried out in the same manner as the resist layer forming step and the pattern transfer step.

Further, in the second configuration example of the image transfer method of the wiring pattern of the present embodiment, the resist layer formation of the semi-additive method in the case of forming the resist layer on the first metal layer of the method for manufacturing the double-sided metal laminate described above. It can be carried out in the same manner as the step and the pattern transfer step.

Therefore, the duplicate description will be omitted.

According to the image transfer method of the wiring pattern of the present embodiment described above, the center value is determined in consideration of the dimensional change rate when patterning is performed, and the pattern is transferred based on the center value. Therefore, when the wiring pattern is formed based on the transferred pattern, it is possible to prevent the wiring pattern from being displaced.

The pattern image transfer method of the embodiment of the present invention can be applied to a method for manufacturing a double-sided wiring board.

Specific examples and comparative examples will be described below, but the present invention is not limited to these examples.

Here, first, an evaluation method of the obtained double-sided metal laminated plate will be described.

The dimensional change rate of the obtained double-sided metal laminate was measured according to IPC-TM-650, 2.2.4, and Method C, and the dimensional stability was evaluated.

In the index of dimensional change rate, contraction is represented by a negative value and expansion is represented by a positive value.

The dimensional change rate when the metal laminate was etched was determined by heat treatment at 150 ° C. for 30 minutes, 23 ° C., 55% relative humidity, and 24 hours according to IPC-TM-650, 2.2.4, and Measurement. The dimensional change rate was measured after the humidity was adjusted in.

Hereinafter, the manufacturing conditions of the double-sided metal laminated board in each Example and Comparative Example will be described.
[Example 1]
As a plastic film, Kapton 100EN (manufactured by Toray DuPont Co., Ltd.), which is a polyimide film having a width of 0.5 m and a length of 3000 m, was prepared (plastic film preparation step). The thickness of the Kapton 100EN used was 25 μm, and the same plastic film was used in Examples 2, 3 and Comparative Examples 1, 3, 7, and 8 below.

Next, a Ni-20% Cr alloy layer having a thickness of 8 nm was formed as a metal seed layer on both sides of the plastic film by a sputtering method (metal seed layer forming step). The Ni-20% Cr alloy means a Ni—Cr alloy composed of 20% by mass of Cr and the balance, that is, 80% by mass of Ni.

Further, a copper layer having a thickness of 0.1 μm was formed as a first metal layer on the metal seed layers formed on both sides of the plastic film (first metal layer film forming step).

The metal seed layer forming step and the first metal layer forming step were continuously carried out by using the film forming apparatus 30 shown in FIG. At the time of film formation, the inside of the chamber 31 is once ^{evacuated to 1 × 10 -4} Pa or less, then argon gas is introduced into the chamber 31 to make the pressure in the chamber 31 0.3 Pa, and then the plastic film F. A metal seed layer and a first metal layer were continuously formed on one surface. Next, after rewinding, a metal seed layer and a first metal layer were continuously formed on the other surface in the same manner. Before forming the metal seed layer and the first metal layer, the plastic film is heated by a heater (not shown) to be in an absolutely dry state. Since the configuration of the film forming apparatus 30 has already been described, the description thereof will be omitted.

Next, a copper layer having a thickness of 0.3 μm was simultaneously formed on both sides of the plastic film, specifically, on the first metal layer as the second metal layer by the electrolytic plating method. The second metal layer was formed by using a continuous electrolytic plating apparatus having the same configuration as the continuous electrolytic plating apparatus 40 shown in FIG. 4, except that the numbers of the anode electrode, the feeding roll, and the dipping roll were different. When forming the second metal layer, the initial value of the current density is set to 0.05 A / dm ^2, and then the current density is gradually increased in steps of 0.04 A / dm ² and finally increased to 2 A / dm ^2. It was. A copper sulfate plating solution was used as the plating solution.

The obtained double-sided metal laminate was evaluated for the dimensional change rate in IPC-TM-650, 2.2.4, and Method C. Table 1 shows the tolerance from the center value calculated from the evaluation result of the dimensional change rate and the center value of the dimensional change rate specified at this time.

The median value of the dimensional change rate was calculated based on the same humidity absorption (humidity control) conditions as Method C (23 ° C., relative humidity 55%, 24 hours) and the change due to tension in the manufacturing process.
[Example 2, Example 3]
A double-sided metal laminated plate was obtained in the same manner as in Example 1 except that the thickness of the second metal layer was set to the thickness shown in Table 1. Table 1 shows the tolerance from the center value calculated from the evaluation result of the dimensional change rate and the calculated center value of the dimensional change rate.
[Examples 4 to 6]
A double-sided metal laminated plate was obtained in the same manner as in Example 3 except that the type of the plastic film was changed to that shown in Table 1. Table 1 shows the tolerance from the center value calculated from the evaluation result of the dimensional change rate and the calculated center value of the dimensional change rate.

In Table 1, Kapton 140ENZ (manufactured by Toray DuPont Co., Ltd.) and Kapton 150ENA (manufactured by Toray DuPont Co., Ltd.) have thicknesses of 35 μm and 38 μm, respectively.

Further, in Table 1, Upirex 35SGAV1 (manufactured by Ube Industries, Ltd.) has a thickness of 35 μm.
[Comparative Examples 1 to 6]
After forming the metal seed layer, the first metal layer, and the second metal layer only on one surface of the plastic film, the metal seed layer, the first metal layer, and the second metal layer are also formed on the other surface of the plastic film. Was formed. Except for the above points, Comparative Examples 1 to 6 produced double-sided metal laminated plates under the same conditions as in Examples 1 to 6, respectively. In Comparative Examples 1 to 6, since the metal laminate is formed on each side, when the second metal layer is formed on one surface, the water content of the plastic film is substantially saturated, while the water content of the plastic film is substantially saturated. By forming the second metal layer on the surface of the plastic film, the shrinkage of the size of the plastic film is suppressed, so that the stretched state (size) of the plastic film is maintained at the same level as in the substantially saturated state. There is. Therefore, the center value of the dimensional change rate of the plastic film is substantially the same as the saturated state, that is, near the origin, and the tolerance when the origin is the center value is shown in Table 1.
[Comparative Examples 7 and 8]
The plastic film is formed during the second metal layer forming step so that the starting point is the point where the heating temperature of the metal seed layer forming step and the first metal layer forming step is lowered and the center value of the dimensional change rate of the plastic film is the origin. The same as in Example 1 except that the time of the second metal layer forming step was lengthened so that the thickness of the second metal layer became the value shown in Table 1 so as to sufficiently absorb moisture. A double-sided metal laminate was obtained. Table 1 shows the tolerance from the center value calculated from the evaluation result of the dimensional change rate and the calculated center value of the dimensional change rate.

表１に示した結果によれば、実施例１〜実施例６においては、中心値からの寸法変化率の公差を十分に抑制できていることが確認できた。

According to the results shown in Table 1, it was confirmed that in Examples 1 to 6, the tolerance of the dimensional change rate from the center value could be sufficiently suppressed.

Therefore, for the double-sided metal laminates of Examples 1 to 6, a resist layer is formed on the second metal layer, the transfer conditions of the pattern are corrected based on the calculated center value, and the pattern is transferred to the resist layer. Then, it was confirmed that when the wiring pattern was formed by using the resist layer, it was possible to suppress the occurrence of deviation in the wiring pattern.

On the other hand, in Comparative Examples 1 to 8, it was confirmed that the tolerance of the dimensional change rate from the center value was large. Then, in Comparative Examples 1 to 6, a resist layer was formed on the second metal layer, the pattern was transferred to the resist layer on the premise that the center value of the dimensional change rate was at the origin, and the resist layer was used. When the wiring pattern was formed, it was confirmed that the wiring was displaced. This is because in Comparative Examples 1 to 6, since the metal laminate is formed on each side, the center value of the dimensional change rate of the plastic film should be near the origin, but the degree of moisture absorption varies. It is thought that it was because of it.

Further, in Comparative Examples 7 and 8, a resist layer was formed on the second metal layer in the same manner as in Examples 1 to 6, and the transfer conditions of the pattern were corrected based on the calculated center value to form the resist layer. The pattern was transferred and a wiring pattern was formed using the resist layer.

However, as a result of adjusting the heating conditions in order to bring the center value of the dimensional change rate closer to the origin, it was confirmed that the tolerance from the center value of the dimensional change rate becomes large and the wiring is displaced.

10 Double-sided metal laminate 11 Plastic film 12A, 12B Metal seed layer 13A, 13B First metal layer 14A, 14B Second metal layer

Claims (13)

With plastic film
A metal seed layer placed directly on both sides of the plastic film,
A double-sided metal laminate having a metal layer arranged on the metal seed layer.
The center value of the dimensional change rate in IPC-TM-650, 2.2.4, and Metal C is in the range of 0.00% or more and 0.06% or less for MD and 0.04% or more and 0.10% or less for TD. A double-sided metal laminate having a dimensional change rate tolerance of ± 0.02% or less for MD and ± 0.01% or less for TD. The double-sided metal laminate according to claim 1, wherein the plastic film is made of polyimide. The double-sided metal laminate according to claim 1 or 2 , wherein the thickness of the plastic film is 25 μm or more and 38 μm or less. The double-sided metal laminate according to any one of claims 1 to 3 , wherein the metal seed layer is a layer made of a Ni—Cr alloy. The double-sided metal laminate according to any one of claims 1 to 4 , wherein the thickness of the metal seed layer is 2 nm or more and 30 nm or less. The double-sided metal laminate according to any one of claims 1 to 5 , wherein the metal layer has a first metal layer and a second metal layer arranged on the first metal layer. The double-sided metal laminate according to claim 6 , wherein the thickness of the first metal layer is 10 nm or more and 300 nm or less. The double-sided metal laminate according to claim 6 or 7 , wherein the total thickness of the metal seed layer and the first metal layer is 350 nm or less. A metal seed layer forming step of forming a metal seed layer on both sides of a plastic film by a dry plating method,
A first metal layer forming step of forming a first metal layer on the metal seed layer by a dry plating method, and
It has a second metal layer forming step of forming a second metal layer on the first metal layer by a wet plating method.
The center value of the dimensional change rate of MD and TD in IPC-TM-650, 2.2.4, Method C is 0.00% or more and 0.06% or less for MD, and 0.04% or more and 0.10 for TD. % or less of the range, the tolerance of the dimensional change rate, MD, within 0.02% ±, TD is the method for producing the double-sided metal clad laminates is within 0.01% ±. A resist layer forming step of forming a resist layer on the first metal layer or the second metal layer,
The resist layer further comprises a pattern transfer step of transferring a pattern using a photomask.
In the pattern transfer step, the pattern is formed based on the center values of the dimensional change rates of MD and TD in IPC-TM-650, 2.2.4, and Method C of the double-sided metal laminated plate before the resist layer forming step. The method for manufacturing a double-sided metal laminate according to claim 9 , wherein the transfer conditions are corrected. In the pattern transferring step, the central value of the dimensional change rate of the double-sided metal laminate when transferring using a photo mask, MD, -0.06% to 0.00% or less, TD is -0.10 % or more is regarded to be less than -0.04%, the method for producing the double-sided metal laminate according to claim 1 0 for correcting the transfer condition of said pattern. This is an image transfer method for wiring patterns.
With plastic film
A metal seed layer placed directly on both sides of the plastic film,
The first metal layer arranged on the metal seed layer and
A double-sided metal laminate having a second metal layer arranged on the first metal layer,
A resist layer forming step of forming a resist layer on the second metal layer,
The resist layer has a pattern transfer step of transferring a pattern using a photomask.
In the pattern transfer step, the pattern transfer conditions are corrected based on the center values of the dimensional change rates of MD and TD in IPC-TM-650, 2.2.4, and Method C of the double-sided metal laminate. Image transfer method. This is an image transfer method for wiring patterns.
With plastic film
A metal seed layer placed directly on both sides of the plastic film,
A double-sided metal laminated precursor plate having a first metal layer arranged on the metal seed layer,
A resist layer forming step of forming a resist layer on the first metal layer,
The resist layer has a pattern transfer step of transferring a pattern using a photomask.
In the pattern transfer step, the pattern transfer conditions are corrected based on the center values of the dimensional change rates of MD and TD in IPC-TM-650, 2.2.4, and Method C of the double-sided metal laminated precursor plate. Image transfer method of pattern.

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