TWI528872B - Metal-covered laminate board - Google Patents

Description

Metal coated laminate

The present invention relates to a metal-clad laminate suitable for use in a flexible circuit substrate, and more particularly to a flexible, flexible metal-clad laminate comprising an insulating layer made of a polyimide resin.

In recent years, with the use of mobile phones, digital cameras, digital cameras, PDAs, car navigation, and hard disk drives, the high-performance, miniaturization, and weight reduction of electronic devices have been adopted as substrates for electrical wiring. An example of a flexible printed circuit board having a high degree of freedom in wiring and a thinner thickness that can be used as a rigid substrate is increasing. Then, in order to increase the height of the flexible printed circuit board used in these devices, it is required to increase the compactness, density, multilayering, miniaturization, and high heat resistance.

In order to cope with such a request, Patent Document 1 and the like disclose a method in which a polyimine resin layer is directly coated on a conductor, and a plurality of polyimine resin layers having different thermal expansion coefficients are formed. It is possible to provide a flexible printed circuit board having excellent reliability such as dimensional stability, adhesion, and planarity after etching.

For a copper-clad laminate which does not have an adhesive layer used in such a flexible printed circuit board, for example, Patent Document 2, Patent Document 3, and Patent Document 4 can be used to increase the adhesion to the resin layer. A copper foil having a roughened surface of the foil.

Further, in recent years, it is necessary to correspond to the increase in the solder bonding temperature with lead-free, as in Patent Document 5, due to the polyimine tree adjacent to the copper foil. When the pressure layer is highly heat-resistant, micropores are easily formed between the copper foil and the polyimide layer during hot pressing, and the acid cleaning liquid infiltrates during circuit processing to cause wiring peeling and the like, and the reliability is lowered. With regard to such a problem, as in Patent Document 6, although there is a method of controlling the plating layer of the roughened surface of the copper foil by suppressing the height of the roughening treatment, there is a concern that the initial peel strength is lowered by such a method, and thus Question.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 6-93537

[Patent Document 2] Japanese Patent Laid-Open No. 2-292894

[Patent Document 3] Japanese Patent Laid-Open No. 6-169168

[Patent Document 4] Japanese Patent Laid-Open No. Hei 8-335775

[Patent Document 5] WO2002/085616

[Patent Document 6] WO2010/010892

SUMMARY OF THE INVENTION An object of the present invention is to provide a metal-clad laminate which not only has a high heat resistance adjacent to a roughened metal foil, but also suppresses generation of a micro-layer between a metal foil and a polyimide layer. The pores and the subsequent reliability of the metal foil and the polyimide layer are improved, so that the circuit peeling due to the penetration of the acid cleaning liquid can be suppressed.

In order to solve the above problems, the inventors of the present invention have found that the roughening characteristics peculiar to the surface of the metal foil are adjacent to the metal foil. The polyimine resin uses a resin having specific characteristics, whereby the above problems can be solved, and the present invention has been completed.

That is, the present invention is a metal-clad laminate having a metal foil on one or both sides of the polyimide layer, and the glass transition temperature of the polyimide layer (i) adjacent to the metal foil is 300 ° C or higher. The roughened surface of the metal foil adjacent to the polyimide layer satisfies the following conditions (a) to (c), and (a) the surface roughness (Rz) of the roughened surface is in the range of 0.5 to 4 μm. (b) The surface layer portion of the roughened surface is a fine protrusion shape formed by a plurality of roughened particles, and in a protrusion of the fine protrusion shape, the height H of the protrusion with respect to the width L of the fundamental portion thereof The aspect ratio (H/L) indicated by the ratio is 1.5 to 5, and the ratio of the protrusion shape in the range of the protrusion height of 1 to 3 μm is 50% or less with respect to the total number of protrusions; (c) the adjacent protrusions The depth between the gaps is 0.5 μm or more, and the ratio of the gap between the adjacent protrusions in the range of 0.001 to 1 μm is 50% or less of the total number of protrusion shapes.

The metal-coated laminate of the present invention has a high heat resistance, and not only exhibits excellent dimensional stability, but also suppresses generation of micropores between the metal foil and the adjacent polyimide layer. Since the flexible wiring board is excellent in chemical resistance during circuit processing, etc., it is suitable for use in a circuit board required for high-precision processing, and its usefulness is very high.

Hereinafter, the present invention will be described in detail.

The metal coated laminate of the present invention is tied to one or both sides of the polyimide layer The surface has a metal foil. If the glass transition temperature of the polyimide layer adjacent to the metal foil is 300 ° C or more, the polyimide layer may be a single layer or a plurality of layers. However, it is preferred that the glass transition temperature be 300 ° C or higher. The polyimine layer (i) is composed of another polyimine layer, and the other polyimide layer has a glass transition temperature of 50 ° C higher than the glass transition temperature of the polyimide layer (i). The above polyimine layer (ii) is composed of. The metal foil is not particularly limited as long as it exhibits a surface roughening shape to be described later. However, copper foil or alloy copper foil is preferred.

When a copper foil or an alloy copper foil is used as the metal foil, the thickness is preferably in the range of 5 to 50 μm, and more preferably in the range of 9 to 30 μm in view of suitability for the flexible wiring board.

The roughened surface adjacent to the polyimide layer of the metal foil used in the present invention must satisfy the following conditions (a) to (c), and (a) the surface roughness (Rz) of the roughened surface is 0.5. (b) the surface layer portion of the roughened surface is a fine protrusion shape formed by a plurality of roughened particles, and the width L of the base portion of the fine protrusion shape with respect to the fundamental portion thereof The aspect ratio (H/L) indicated by the ratio of the protrusion height H is in the range of 1.5 to 5, and the ratio of the protrusion shape in the range of the protrusion height of 1 to 3 μm is 50% or less with respect to the total number of protrusions; (c) The depth between the adjacent protrusions is 0.5 μm or more, and the ratio of the gap between the adjacent protrusions in the range of 0.001 to 1 μm is 50% or less of the total number of protrusion shapes.

First, the surface roughness (Rz) of the roughened surface must be in the range of 0.5 to 4 μm. When the Rz value is less than 0.5 μm, the metal foil and the polyimide layer are connected. When the force is lowered, when the thickness exceeds 4 μm, the etching residue during the micro pattern processing of the circuit increases, and as a result, the electrical reliability is lowered. Here, the surface roughness (Rz) of the roughened surface refers to Rz defined by the definition of "5.1+point average roughness" of "Definition and Expression of Surface Thickness" in JIS B 0601-1994.

Then, the surface layer portion of the roughened surface is a fine protrusion shape formed by a plurality of roughened particles, and the ratio of the protrusion height H of the width L of the fundamental portion of the protrusion of the fine protrusion shape is The aspect ratio (H/L) is in the range of 1.5 to 5, and the ratio of the protrusion shape in the range of the protrusion height of 1 to 3 μm is required to be 50% or less with respect to the total number of protrusion shapes. When the condition of the aspect ratio and the height of the protrusion exceeds 50%, the surface roughening shape becomes thick, and when the polyimine layer having a high heat resistance (glass transition temperature) is heated, the fluidity is insufficient and becomes It is easy to produce micropores.

Further, in the roughened surface of the surface of the metal foil, the depth between the adjacent protrusions is 0.5 μm or more, and the ratio of the gap between the adjacent protrusions in the range of 0.001 to 1 μm must be the total number of protrusions. 50% or less. When the ratio exceeds 50%, the filling of the gap by the resin is not sufficiently performed, and micropores are easily generated.

Here, the roughened surface of the metal foil used in the present invention will be described using FIG. Fig. 1 is a schematic representation of a surface portion of a metal foil cross section enlarged. In the present invention, the aspect ratio of the fine protrusion shape of the roughened surface is, for example, the value H of the protrusion of one of the fine protrusion shapes divided by the width L of the root portion of the protrusion as shown in Fig. 1 . The height of the protrusions represents the value of the longest length starting from the center of the bottom connection of the adjacent valleys.

Further, when the condition of the above condition (c) of the present invention is mentioned, a gap having a depth of 0.5 μm or more is formed between adjacent protrusions, and it is judged that the distance between adjacent protrusions in the gap is 0.001 to 1 μm. There is a ratio. In the first drawing, the projection p and the projection q are adjacent projections, and the projections p and q have a gap of 0.5 μm or more. Then, the distance between the adjacent portions is in the range of 0.001 to 1 μm. In the present invention, the smaller the gap, the better, in other words, the condition of (c) is a gap having a depth between the protrusions of 0.5 μm or more, and the distance between the adjacent points of the depth is 0.001 to 1 μm with respect to all the protrusions. The number of shapes is 50% or less.

The roughened shape formed on the surface of the metal foil used in the present invention has a width larger than the width L of the root portion in the direction of the apex direction, and the ratio of the protrusion shape is preferably 20% or less, more preferably 20% or less. It is 10% or less. When the ratio exceeds 20%, there is a tendency that micropores are easily generated at the fundamental portion of the protrusion shape.

In the roughened surface of the metal foil of the present invention, when the shape of the roughened protrusion is elongated, the micropores tend to be generated. Therefore, the average width of the protrusion shape having a height of 1 μm or more is 1 μm or more. The proportion occupied by the shape is preferably 10% or more, more preferably 30% or more. Here, the average width of the protrusion shape may have a width of 1/2 of the height of the protrusion as the average width. Further, commercially available such roughened copper foil may be obtained from commercially available products as long as the conditions of the roughened surface of the present invention are satisfied.

It is preferable that the roughened surface of the metal foil is subjected to Ni, Zn, and Cr plating treatment, and the Ni content is 0.1 mg/dm ² or more, and the Y value (brightness) measured by the luminance meter is 25 or more. This brightness is the light on the surface of the sample, and the amount of light reflected is used as the brightness. Therefore, it is an indicator for observing the surface roughness. Low brightness means that the reflectance is low, and it means that the gap between adjacent protrusions is mostly narrow, and it is easy to generate micropores during hot pressing. When the Ni content is less than 0.1 mg/dm ² , the corrosion resistance is insufficient, and not only the filling property of the polyimide, but also the acid is corroded.

Next, a polyimide layer as an insulating layer in the metal-clad laminate of the present invention will be described.

As described above, in the present invention, the polyimine layer must be a polyimine layer (i) as a layer adjacent to the metal foil, preferably composed of a plurality of layers of polyimide layers. As a configuration example of a preferable specific polyimine layer, the following structural examples are mentioned. Further, in the following configuration examples, M is an abbreviation for metal foil, PI is an abbreviation for polyimine, and further, PI layer (i) is a polyimide layer having a glass transition temperature of 300 ° C or higher, and a PI layer ( Ii) is a layer having a glass transition temperature higher than 50 ° C above the polyimine layer (i).

(1) M/PI layer (i) / PI layer (ii) / PI layer (i)

(2) M/PI layer (i) / PI layer (ii) / PI layer (i) / M

(3) M/PI layer (ii) / PI layer (i) / M

The polyimine which constitutes the polyimide layer is generally represented by the following formula (1), and can be substantially polymerized by using a diamine component and an acid dianhydride component by a known method in an organic polar solvent. Manufacturing.

Here, Ar ₁ is a tetravalent organic group having one or more aromatic rings, Ar ₂ is a divalent organic group having one or more aromatic rings, and n represents a repeating number. That is, Ar ₁ is a residue of an acid dianhydride, and Ar ₂ is a residue of a diamine.

Examples of the solvent used in the polymerization of the polyimine include dimethylacetamide, n-methylpyrrolidone, 2-butanone, diglyme, and xylene. These may be used alone or in combination of two or more. Further, the resin viscosity of the polylysine (polyimine precursor) which can be obtained by polymerization is preferably in the range of 500 cps to 35,000 cps.

The diamine component and the acid dianhydride component used as a raw material may be various raw material components exemplified below, in consideration of various properties required for the polyimide phase (i) and the polyimide phase (ii) constituting the insulating layer. Choose the most appropriate one.

The acid dianhydride is preferably an aromatic tetracarboxylic dianhydride represented by O(CO) ₂ -Ar ₁ -(CO) ₂ O, and an aromatic acid anhydride residue represented by the following formula (2) is used as Ar _{1 .} The winner is an example.

Further, as the diamine, for example, an aromatic diamine represented by H ₂ N-Ar ₂ -NH _{2 is} preferably obtained by using an aromatic diamine residue represented by the following formula (3) as Ar ₂ . .

Formula (3)

The polyimine layer (i) in the present invention is a polyimide layer having a glass transition temperature of 300 ° C or higher adjacent to the metal foil. From the viewpoint of adhesion to the metal foil, the polyimide layer (i) must exhibit thermoplasticity upon heating and pressing of the metal foil, however, heat resistance decreases as the glass transition temperature is low. From this point of view, the preferred glass transition temperature of the polyimine layer (i) is preferably less than 350 °C.

The acid dianhydride component constituting the polyimine layer (i) may, for example, be as described above. In the formula (2), pyromellitic dianhydride (PMDA) is used as an essential component, and as a main component, it is particularly preferable to use 80 mol% or more. Further, the diamine component constituting the polyimine layer (i) may, for example, be represented by the above formula (3), particularly 2,2-bis[4-(4-aminophenoxy)phenyl group. Propane (BAPP) is an essential component, and as such a main component, it is particularly preferable to use 80 mol% or more. Here, two or more kinds of other acid dianhydrides and diamine components may be used in combination.

The polyimine layer (ii) in the present invention is a layer having a glass transition temperature higher than that of the polyimine layer (i) by 50 °C or higher. From the viewpoint of adhesion to the metal foil, the polyimide layer (ii) is not directly in contact with the metal foil, and it is preferably integrated with the metal foil via the polyimide layer (i).

The acid dianhydride component constituting the polyimine layer (ii) is preferably selected from the group consisting of pyromellitic dianhydride (PMDA) and 3,3',4,4'-biphenyltetracarboxylic acid. Anhydride (BPDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenylphosphonium tetracarboxylic dianhydride (DSDA) And 4,4'-oxydiphthalic acid dianhydride (ODPA), these may be used individually or in mixture of 2 or more types.

Further, the diamine component constituting the polyimine layer (ii) may be listed as, for example, diaminodiphenyl ether (DAPE), 2'-methoxy-4,4'-diaminobenzene. Methamine benzene (MABA), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB), p-phenylenediamine (P-PDA), 1,3-double ( 4-aminophenoxy)benzene (TPE-R), 1,3-bis(3-aminophenoxy)benzene (APB), 1,4-bis(4-aminophenoxy)benzene ( TPE-Q) and 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) may be used alone or in combination of two or more.

The thickness of the polyimine layer in the present invention is preferably from 8 to 40 μm, more preferably from 9 to 30 μm. In addition, the polyimine layer (i) acts to remain with the metal The adhesion of the layer and the balance due to the linear expansion coefficient of the entire insulating layer are controlled, and the thickness thereof is preferably in the range of 1 to 3 μm. The polyimine layer (i) may be disposed on one or both sides of the polyimide layer (ii).

As described above, in the present invention, the insulating layer is composed of a single layer or a plurality of layers of a polyimide layer. Therefore, in the present invention, it is preferred that the entire insulating layer (the entire polyimide layer) has a linear expansion coefficient (CTE) of 10 The range of ×10 ^-6 to 25 × 10 ^-6 [1/K] is preferable. When the polyimine layer is a plurality of layers, the linear expansion coefficient (CTE) of the polyimine layer (ii) is preferably 30 × 10 ^-6 or less, particularly preferably 1 × 10 ^-6 to 20 × 10 ^-6 The range of [1/K]. Further, in this case, the polyimine layer (i) is preferably in the range of 20 × 10 ^-6 to 60 × 10 ^-6 [1/K], and is 30 × 10 ^-6 to 50 × 10 ^-6 [ The range of 1/K] is exceptional.

In the method for producing a metal-clad laminate according to the present invention, the above-mentioned configuration example (2) of the laminate is [M/PI layer (i) / PI layer (ii) / PI layer (i) / M]. Basic description. Further, in the following examples, M is a copper foil.

In this example, first, a polyamic acid solution as a polyimide precursor to be a polyimine layer (i) is directly coated on the surface of the roughened copper foil, and the resin solution is placed in the resin solution. The solvent contained is removed to a certain extent at a temperature of 150 ° C or lower.

Next, the polyamic acid solution for forming the polyimine precursor of the polyimine layer (ii) is directly applied, and the solvent contained in the resin solution is removed to a certain temperature at a temperature of 150 ° C or lower.

Then, the polyamic acid solution for forming the polyimine precursor of the polyimine layer (i) is directly coated, and the solvent contained in the resin solution is removed to a certain temperature at a temperature of 150 ° C or lower. . So, forming a complex on the copper foil The solution of the plurality of layers is removed to a certain degree of the polyimide precursor layer, and further heat-treated at a temperature ranging from 100 to 450 ° C, preferably from 300 to 450 ° C for about 5 to 40 minutes, and the solvent is removed.醯imination.

In this state, a single-sided copper-clad laminate composed of three layers of polyimide layers is formed on the copper foil, and the polyimide layer of the single-sided copper-clad laminate is heated on the surface side (i). Processed copper foil. The heat-adhesive system is heated and pressed at a temperature slightly higher than the glass transition temperature of the polyimide layer (i), and the copper foil of the above-described specific roughened surface is used in the present invention, thereby suppressing the generation of micropores. In this example, the roughened copper foil is used on both sides of the polyimide layer. However, in another aspect of the invention, the specific copper foil specified above may be used only on the copper foil of the appropriate heat-pressed side.

Therefore, in the case where the polyimide having a high glass transition temperature is used for the layer adjacent to the metal foil requiring heat resistance, the dimensional stability can be maintained by using the roughened copper foil having a specific surface property. Other properties such as properties and adhesions are coated with the properties of the laminate, and the generation of micropores can be suppressed.

Example

Hereinafter, the present invention will be described in more detail on the basis of examples. Further, in the following examples, various evaluations are as follows, unless otherwise noted.

[Measurement of glass transition temperature]

The base copper foil was etched into a film-state polyimine, and the peak of tan δ measured at a temperature of 1.0 Hz in a tensile mode was used using a dynamic viscoelasticity measuring device (RSA-III) manufactured by SII Nanotechnology Co., Ltd. Make the glass transfer temperature.

[Evaluation of roughening surface]

The shape of the roughened surface was evaluated by FE-SEM (S-4700, manufactured by Hitachi High-tech Co., Ltd.), which was produced by a cross section polisher (SM-09010, manufactured by JEOL Ltd.). The shape of the roughened portion in the range of 25 μm in width was evaluated.

Further, the amount of Ni in the roughened surface was measured by ICP-AES (Optima 4300, manufactured by Perkinelmer Co., Ltd.) which was dissolved in 1 N nitric acid only on the surface adjacent to the polyimide. Further, the brightness Y was measured using SM-4 manufactured by Sugatest.

[Measurement of acid resistance]

The acid resistance was measured by a circuit with a line width of 1 mm on a flexible single-sided copper-clad laminate, and after being immersed in an aqueous solution of 18 wt% hydrochloric acid at 50 ° C for 60 minutes, the side of the insulating layer (polyimine layer) was The width of the discoloration due to the infiltration of hydrochloric acid was measured at the end of the circuit using a 200-fold optical microscope. Here, the case where the hydrochloric acid penetration width is 200 μm or less is evaluated as excellent.

[Measurement of adhesion (peeling strength)]

The adhesive force between the copper foil and the polyimide film layer is a circuit processing of a flexible single-sided copper-clad laminate obtained by forming an insulating layer made of a polyimide resin on the copper foil by a line width of 1 mm. The copper foil was peeled off in the 180° direction using a tensile tester (STROGRAPH-M1) manufactured by Toyo Seiki Co., Ltd., and the initial peel strength was measured. Further, the peel strength after the acid resistance measurement and the peel strength after acid resistance were measured. The initial peel strength × 100% was taken as the retention rate.

Synthesis Example 1

N,N-dimethylacetamide was poured into a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen. In the reaction vessel, 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP) was dissolved while stirring in a vessel. Next, pyromellitic dianhydride (PMDA) was added to make the total amount of the monomer input 12 wt%. Thereafter, stirring was continued for 3 hours to obtain a resin solution b of polyglycine. The solution viscosity of the polyacetic acid resin solution b was 3,000 cps. The polyimine obtained from the polyamine showed a linear expansion coefficient of more than 30 × 10 ^-6 (1/K) and a glass transition temperature of 315 °C.

Synthesis Example 2

N,N-dimethylacetamide was poured into a reaction vessel equipped with a thermocouple and a stirrer and capable of introducing nitrogen. In the reaction vessel, 2,2'-dimethyl-4,4'-aminobiphenyl (m-TB) was dissolved while stirring in a vessel. Next, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA) were added. The total amount of the monomers to be supplied was 15% by weight, and the molar ratio (BPDA: PMDA) of each of the acid anhydrides was 20:80. Thereafter, stirring was continued for 3 hours to obtain a resin solution a of polylysine. The solution viscosity of the polyaminic acid resin solution a was 20,000 cps. The polyimine obtained from the polyamic acid thus exhibits a low coefficient of linear expansion of 20 × 10 ^-6 (1/K) or less and has a non-thermoplastic property.

Example 1

An electrolytic copper foil having a roughened surface shown in Table 1 treated with a decane coupling agent having an amine group as a surface treatment layer was prepared as a copper foil. This copper foil had a thickness of 12 μm and a surface roughness of (Rz) of 1.2 μm. On the copper foil, the resin solution b of the polyaminic acid prepared in Synthesis Example 2 is sequentially coated, The resin solution a of the polyamic acid adjusted in the synthesis example 1 and the resin solution b of the polyamic acid prepared in the synthesis example 2 were subjected to a heat treatment at a final temperature of 300 ° C or more for about 10 minutes to obtain a polyimine layer. A flexible single-sided copper-coated laminate having a thickness of 25 μm. Further, the polyimide layer has a layer of 21 μm obtained from a resin solution a of poly-proline, and a layer of 2 μm each obtained from a resin solution b of poly-proline on both sides thereof.

The thus obtained flexible single-sided copper-coated laminate was further subjected to heating and pressing under the heating/pressurization of the copper foil of the same type as described above by heating and pressing. The evaluation of the peel strength and the acid resistance was carried out on the side of the heated pressure-bonding surface of the flexible double-sided copper foil-clad laminate, and the initial adhesion of 1 mm between the copper foil and the polyimide layer was 1.95 kN/m. Further, the penetration resistance width of the circuit of the circuit was 69 μm, and the peel strength retention was 89%. The results are shown in Table 2.

Example 2, 3, Comparative Example 1, 2

The peeling strength, the hydrochloric acid infiltration property, and the peeling retention ratio were evaluated in the same manner as in Example 1 except that the electrolytic copper foil shown in Table 1 in which the amount of surface metal was different was used. The results are shown in Table 2.

Although not shown in Table 1, the roughened surface of all the copper foils used in the examples and the comparative examples was subjected to Ni, Zn, and Cr plating treatment. In Table 1, (b) the high aspect ratio number/the total number of protrusions indicates the range of the aspect ratio (H/L) of 1.5 to 5 with respect to the total number of protrusions measured, and the protrusion height is 1 to 3 μm. The proportion of the number of people in the range.

(c) The gap between the protrusions/the total number of protrusions is expressed relative to the measured The total number of protrusions has a ratio of a depth between adjacent protrusions of 0.5 μm or more and a distance between adjacent protrusions in a range of 0.001 to 1 μm.

Further, (d) the number of expanded protrusions/the total number of protrusions represents a ratio of the number of protrusion shapes having a width L wider than the root width with respect to the total number of protrusions measured.

Further, (e) the average width of the projections of 1 μm or more and the total number of projections indicates the ratio of the number of projections having an average width of 1 μm or more with respect to the total number of projections measured. Further, a photograph of a cross section of the copper foil used in Example 1 is shown in Fig. 2, and a photograph of a cross section of the copper foil used in Comparative Example 2 is shown in Fig. 3. Here, the finely roughened surface of the surface of the copper foil-based Rz phase used in Examples 2 and 3 is similar to that of FIG. 2, and the surface of the copper foil Rz used in Comparative Example 1 is finely roughened. The shape is similar to Figure 3.

The copper-clad laminate obtained in Examples 1, 2, and 3 was confirmed to have a discoloration of 200 μm or less at the end of the circuit after the hydrochloric acid treatment, and the peel strength retention ratio was 70% or more. On the other hand, it was confirmed that all of the circuit end portions in Comparative Examples 1 and 2 were discolored due to peeling of the circuit, and the peel strength retention ratio was less than 70%.

The flexible copper-clad laminate obtained by the invention inhibits hydrochloric acid treatment After the infiltration, the circuit does not peel off, so it is confirmed to be a material with high reliability.

L‧‧‧Width of the fundamental part of the fine protrusion shape

H‧‧‧ Height of fine protrusion shape

P‧‧‧ adjacent to the protrusion of q

Q‧‧‧ adjacent to the 1 protrusion of p

Fig. 1 is a schematic view for explaining the roughened shape of a copper foil cross section of a copper foil.

Fig. 2 is a photograph showing a cross section of a copper foil of the copper foil used in Example 1.

Fig. 3 is a photograph of a cross section of a copper foil of a copper foil used in Comparative Example 2.

L‧‧‧Width of the fundamental part of the fine protrusion shape

H‧‧‧ Height of fine protrusion shape

P‧‧‧ adjacent to the protrusion of q

Q‧‧‧ adjacent to the 1 protrusion of p

Claims (6)

A metal-clad laminate in which a metal-coated laminate having a metal foil on one side or both sides of a polyimide layer has a glass transition temperature of 300 ° C or more, the aforementioned The roughened surface (i) adjacent to the polyimide layer of the metal foil satisfies the conditions (a) to (c) below, and (a) the surface roughness (Rz) of the roughened surface is 0.5 to 4 μm. (b) The surface layer portion of the roughened surface is a fine protrusion shape formed by a plurality of roughened particles, and the ratio of the protrusion height H of the width L of the base portion with respect to the protrusion of the fine protrusion shape is The aspect ratio (H/L) indicated is in the range of 1.5 to 5, and the ratio of the protrusion shape in the range of the protrusion height of 1 to 3 μm is 50% or less with respect to the total number of protrusions; (c) the protrusions adjacent to each other The depth of the gap formed between the gaps is 0.5 μm or more, and the number of gaps between the adjacent protrusions in the range of 0.001 to 1 μm is 50% or less of the total number of protrusion shapes across the depth direction of the gap. The metal-coated laminate according to the first aspect of the invention, wherein in the projection shape defined in the first item (b) of the patent application, the ratio of the protrusion shape in which the width toward the vertex direction is larger than the width L of the root portion The number of all protrusion shapes is 20% or less. The metal-clad laminate according to the first or second aspect of the invention, wherein the ratio of the average width of the protrusion shape having a height of 1 μm or more to 1 μm or more is 10% or more in all the protrusion shapes. The metal coated laminate according to the first or second aspect of the invention, wherein the roughened surface is treated with Ni, Zn and Cr, and the Ni content is 0.1 mg/dm ² or more, and the brightness is measured. The Y value (brightness) of the amount is 25 or more. The metal-clad laminate according to claim 1 or 2, wherein the glass transition temperature of the polyimine layer (ii) which is composed of a plurality of layers of polyimine layers and which is not adjacent to the metal foil It is higher than the glass transition temperature of the polyimine layer (i) by 50 ° C or more. The metal-clad laminate according to the first or second aspect of the invention, wherein the polyimine resin layer and the metal foil have an initial adhesion force of 1 kN/m or more in a width of 1 mm, and are immersed in hydrochloric acid for 1 hour. The subsequent peel strength retention rate was 80% or more.