TWI699280B - Surface-treated copper foil and copper-clad laminate or printed wiring board manufactured using the surface-treated copper foil - Google Patents

Abstract

The present invention provides surface-treated copper foils, etc., which are suitable for copper-clad laminates or printed wiring boards that can support high-performance and high-functionality of high-frequency information communication equipment.

The surface-treated copper foil (M) of the present invention is used to form a copper-clad laminate by lamination and bonding with a first resin substrate (B1) with a dielectric constant of 2.6 to 4.0, which is used with the first resin substrate (B1) The bonding surface has a surface treatment layer that satisfies the condition 1 shown below.

Supplement

Condition 1: When the second resin substrate (B2) is laminated and bonded on the surface of the first resin substrate (B1) obtained by dissolving the copper foil part from the copper-clad laminate by etching, the first resin substrate ( B1) The interface height (H) of the bonding interface (S) with the second resin substrate (B2) is 0.15 to 0.85μm, and the number of concavities and convexities present in the bonding interface (S) is 11 to 30 per 2.54μm width .

Description

Surface-treated copper foil and copper-clad laminate or printed wiring board manufactured using the surface-treated copper foil

The present invention relates to a surface-treated copper foil and a copper-clad laminate or printed wiring board manufactured using the surface-treated copper foil. The surface-treated copper foil is suitable for high-frequency substrates such as wireless radars, high-speed computing machines, and portable devices. , Especially suitable for servers, etc.

In recent years, with the advancement of high-performance and high-functionality of computers and information communication equipment, and even the development of networking, in order to transmit and process large-capacity information at high speeds, there is a tendency for signals to gradually increase in frequency. This kind of information communication equipment uses a copper-clad laminate. The copper-clad laminate is made by heating and pressing an insulating substrate (resin substrate) and copper foil.

Generally, insulating substrates supporting high-frequency copper-clad laminates must use resins with excellent dielectric properties. However, there is a trend that resins with lower relative permittivity and dielectric loss tangent help to bond with copper foil There are fewer functional groups with higher polarity, and the adhesion to copper foil is reduced.

In addition, it is required to reduce the surface roughness of the copper foil used as a conductive layer for supporting high frequency copper clad laminates as much as possible. The low profile of the copper foil is required because the current concentrates on the surface of the copper foil as the high frequency current flows, and there is a tendency that the greater the surface roughness of the copper foil, the greater the transmission loss.

In order to improve the adhesion to the copper foil insulating substrate constituting the copper-clad laminate, a roughened layer formed by electrodeposition of roughened particles is usually formed on the copper foil substrate, and the physical effect (fixation effect) is used to improve the adhesion . If the height difference (surface roughness) is increased, the adhesion will increase. However, although the transmission loss increases for this reason, the current situation is to preferentially use the roughened particles of the roughened layer formed on the copper foil substrate to ensure the adhesion. The roughening leads to a certain degree of reduction in transmission loss. However, in recent years, the development of next-generation high-frequency circuit boards that support frequencies above 20 GHz has continued to develop, and the boards are required to further reduce transmission loss than in the past.

In general, in order to reduce transmission loss, it is preferable to use, for example, a surface-treated copper foil that reduces the difference in height (surface roughness) of the fine surface irregularities of the roughened layer, or a non-roughened smooth copper foil without roughening treatment. In order to ensure the adhesion of the copper foil with small surface roughness, it is preferable to form a silane coupling agent layer with a chemical bond between the copper foil and the insulating substrate.

When using this copper foil to manufacture high-frequency circuit boards, in addition to the above-mentioned adhesion and transmission characteristics, it is necessary to consider reflow heat resistance in recent years.

Here, "reflow heat resistance" refers to the heat resistance of the reflow process performed when manufacturing high-frequency circuit boards. The reflow process refers to a method of soldering by heating in a reflow furnace in a state where the paste flux is attached to the connection point between the wiring of the circuit board and the electronic component. In recent years, from the viewpoint of reducing the environmental load, the lead (Pb)-free soldering flux used in the electrical joints of circuit boards is being developed. The Pb-free flux has a higher melting point than the past flux. When used in the reflow process, the circuit board is exposed to a high temperature of, for example, about 260°C. Therefore, compared with the use of the past flux, a higher level of reflow is required Heat resistance. Therefore, in particular For the copper foil used for this purpose, it is new to ensure sufficient adhesion to the insulating substrate, and to combine the reflow heat resistance and transmission characteristics of the circuit substrate (printed wiring board) made with the copper foil at a high level. Subject.

For example, the applicant has proposed a method in Patent Document 1, which uses a potassium hydroxide solution to form fine irregularities on the surface of a thermoplastic resin film, and then sequentially performs electroless copper plating and electrolytic copper plating to form a surface shape derived from the thermoplastic resin film. The copper layer with fine concavities and convexities is produced as a metal-clad laminate of the circuit board, and it has been disclosed that it has excellent transmission characteristics and adhesion. However, after the applicant further discussed the invention described in Patent Document 1, it was learned that sometimes sufficient reflow heat resistance may not be obtained, and there is still room for improvement.

Patent Document 2 discloses a surface-treated copper foil, which is formed by roughening the surface with a surface roughness (Rzjis) of less than 1.0 μm and controlling the surface area after the roughening. It has been known that this kind of copper foil has good transmission characteristics when applied to high-frequency circuit boards, but because the surface profile is low, it is used in applications requiring high-level reflow heat resistance such as current high-end server applications. , Does not meet the characteristics.

Furthermore, Patent Document 3 discloses a surface-treated copper foil for a copper-clad laminate, which is formed by forming roughened particles by a roughening treatment using copper-cobalt-nickel alloy plating. When this kind of copper foil is applied to a high-frequency circuit board, the contact area between the copper foil and the resin is increased, so good adhesion can be ensured. However, because the surface area of the copper foil is too large, the transmission characteristics are expected to be poor and heat-resistant to reflow No consideration is given to sex.

【Advanced Technical Literature】 【Patent Literature】

Patent Document 1: Japanese Patent Laid-Open No. 2013-158935

Patent Document 2: Japanese Patent No. 5129642

Patent Document 3: Japanese Patent Laid-Open No. 2013-147688

The object of the present invention is to provide a surface-treated copper foil and a copper-clad laminate or printed wiring board manufactured using the surface-treated copper foil. The surface-treated copper foil is suitable for supporting high-performance and high-frequency information communication equipment. The functionalized copper-clad laminate or printed wiring board, in the copper-clad laminate or printed wiring board made of the surface-treated copper foil, can ensure that the surface-treated copper foil and the dielectric constant and dielectric loss tangent are low and medium The resin substrate with excellent electrical properties has sufficient adhesion, and can meet the reflow heat resistance and transmission characteristics at a high level.

As a result of intensive research, the inventor found a surface-treated copper foil, which is used to form a copper-clad laminate by lamination and bonding with a resin substrate with a certain dielectric constant. The surface treatment of the copper foil and the resin substrate The bonding surface has a roughened layer that has been appropriately controlled to meet the specified conditions. It can produce copper-clad laminates that ensure sufficient adhesion between the surface-treated copper foil and the resin substrate and have excellent reflow heat resistance and high-frequency characteristics. The wiring board is printed, thereby completing the present invention.

That is, the main structure of the present invention is as follows.

(1) A surface-treated copper foil, which is used to form a copper-clad laminate by lamination and bonding with a first resin substrate with a dielectric constant of 2.6 to 4.0, and is characterized in that it is attached to the first resin substrate The mating surface has a surface treatment layer satisfying condition 1 shown below.

Supplement

Condition 1: When a second resin substrate is laminated and bonded on the surface of the first resin substrate obtained by dissolving the copper foil part from the copper-clad laminate by etching, the first resin substrate and the second resin The interface height of the bonding interface of the substrate is 0.15 to 0.85 μm, and the number of concavities and convexities existing in the bonding interface is 11 to 30 per 2.54 μm width.

(2) The surface-treated copper foil described in (1) above, wherein the number of concavities and convexities existing in the bonding interface is 15 to 25 per 2.54 μm width.

(3) The surface-treated copper foil described in (1) or (2) above, wherein the interface height of the bonding interface is 0.18 to 0.50 μm.

(4) The surface-treated copper foil as described in (3) above, wherein the interface height of the bonding interface is 0.20 to 0.25 μm.

(5) The surface-treated copper foil according to any one of (1) to (4) above, wherein the dielectric constant of the first resin substrate is 3.0 to 3.9.

(6) The surface-treated copper foil according to any one of the above (1) to (5), wherein the interface inclination angle θ existing at the bonding interface is 15° to 85°.

(7) The surface-treated copper foil described in (6) above, wherein the interface inclination angle θ existing at the bonding interface is 20° to 70°.

(8) A copper-clad laminate, which combines the surface-treated copper foil described in any one of (1) to (7) above and the first resin substrate with the bonding surface of the surface-treated copper foil and The first resin substrate is formed by laminating and bonding the first resin substrate to face each other.

(9) A printed wiring board using the surface-treated copper foil as described in any one of (1) to (7) above.

(10) A printed wiring board having a dielectric constant of 2.6 to 4.0 One or more resin laminates formed by laminating and bonding the first resin substrate and the second resin substrate, characterized in that: the interface of the bonding interface between the first resin substrate and the second resin substrate The height is 0.15 to 0.85 μm, and the number of concavities and convexities existing in the bonding interface is 11 to 30 per 2.54 μm width.

(11) The printed wiring board according to the above item (10), wherein the number of concavities and convexities existing in the bonding interface is 15 to 25 per 2.54 μm width.

(12) The printed wiring board as described in (10) or (11) above, wherein the interface height of the bonding interface is 0.18 to 0.50 μm.

(13) The printed wiring board according to the above item (12), wherein the interface height of the bonding interface is 0.20 to 0.25 μm.

(14) The printed wiring board according to any one of (10) to (13) above, wherein the dielectric constant of the first resin substrate is 3.0 to 3.9.

(15) The printed wiring board according to any one of the above (10) to (14), wherein the interface inclination angle θ existing at the bonding interface is 15° to 85°.

(16) The printed wiring board according to the above item (15), wherein the inclination angle θ of the interface existing at the bonding interface is 20° to 70°.

The present invention can provide a surface-treated copper foil and a copper-clad laminate or printed wiring board manufactured by using the surface-treated copper foil. The surface-treated copper foil is suitable for high-frequency support capable of supporting high-speed transmission of large-capacity information. High-performance and high-function copper-clad laminates or printed wiring boards for information and communication equipment. In the copper-clad laminates or printed wiring boards made of the surface-treated copper foil, the surface-treated copper foil and dielectric constant can be ensured And sufficient adhesion of resin substrates with low dielectric loss tangent and excellent dielectric properties, and can be used with high water It satisfies reflow heat resistance and transmission characteristics.

B1‧‧‧The first resin substrate (or resin core layer)

B2‧‧‧Second resin substrate (or prepreg layer)

BL1, BL2‧‧‧Baseline

BL3‧‧‧line

C‧‧‧Void (or crack)

F1‧‧‧Expansion force of gas

F2‧‧‧Shear force

F3‧‧‧Friction

H‧‧‧Interface height

M, M1‧‧‧Surface treated copper foil

M2‧‧‧Copper foil

P‧‧‧Copper clad laminate

S‧‧‧Glue interface

T1, T2‧‧‧Test piece

θ、θ1、θ2‧‧‧Interface tilt angle

Figure 1 (a) and (b) are the first resin substrate (resin core layer) B1 and the second resin substrate (prepreg layer) B2 obtained by dissolving the copper foil portion M1 from the copper-clad laminate P A conceptual diagram when using a scanning electron microscope (SEM) to observe the bonding interface S between the resin core layer B1 and the prepreg layer B2 during lamination bonding. Figure 1(a) shows the bonding at low magnification (for example, 10000 times) In the case of the interface, Figure 1(b) shows the observation of the bonding interface at a high magnification (for example, 50,000 times).

Fig. 2 is a conceptual diagram for explaining the method of measuring the number of concavities and convexities of the bonding interface S between the resin core layer B1 and the prepreg layer B2 shown in Fig. 1(b).

Figure 3 (a) to (c) are used to summarize the reflow heat resistance test that causes the volatilization of the components in the resin substrates B1 and B2, and the volume of gas generated is stored in the bonding interface S between the resin core layer B1 and the prepreg layer B2 The graph of the time-dependent change of the expansion force F1 of the gas generated by the gap C on the bonding interface S shows the shear generated by the expansion force F1 of the gas along the direction parallel to the bonding interface S The force F2 is smaller than the friction force F3 generated by the bonding interface S in the opposite direction of the shear force F2.

Figure 4 (a) to (c) are used to summarize the reflow heat resistance test that causes the volatilization of the components in the resin substrate B1 and B2 and the gas generated by the volume is stored in the bonding interface S between the resin core layer B1 and the prepreg layer B2 The graph of the time-dependent change of the expansion force F1 of the gas generated by the gap C on the bonding interface S shows that the expansion force F1 of the gas is generated along the parallel direction of the bonding interface S The shearing force F2 is greater than the frictional force F3 generated by the bonding interface S in the opposite direction of the shearing force F2.

Figure 5 (a) to (d) are diagrams for explaining the method of making a test piece (multilayer board) T1 for measuring the interface height H of the bonding interface S between the first resin substrate B1 and the second resin substrate B2 .

Figure 6 (a) to (d) are diagrams for explaining the method of making the test piece T2 for the reflow heat resistance test.

Figure 7 is a comparison of Examples 1 to 20 and Comparative Examples 1 to 17 shown in Table 2, with the interface height H of the bonding interface between the first resin substrate and the second resin substrate as the horizontal axis, and the unevenness of the bonding interface The figure is when the vertical axis is drawn.

Figures 8(a) and (b) are measurement examples of the interface tilt angle θ existing at the bonding interface. Figure 8(a) shows the case where the interface tilt angle θ1 is within the appropriate range (70°) of the present invention. Figure 8( b) indicates the case where the interface tilt angle θ2 is outside the proper range (100°) of the present invention.

Figures 8(a) and (b) are measurement examples of the interface tilt angle θ existing at the bonding interface. Figure 8(a) shows the case where the interface tilt angle θ1 is within the appropriate range (70°) of the present invention. Figure 8( b) indicates the case where the interface tilt angle θ2 is outside the proper range (100°) of the present invention.

Hereinafter, embodiments of the surface-treated copper foil according to the present invention will be described with reference to the drawings.

Fig. 1 schematically shows the bonding interface S between the first resin substrate (resin core layer) B1 and the second resin substrate (prepreg layer) B2 in the multilayer board T1. The multilayer board T1 is laminated with the first resin substrate B1 and the surface-treated copper foil of the present invention to form a copper clad Laminate, by laminating and bonding the first resin substrate (resin core layer) B1 and the second resin substrate (prepreg layer) B2 obtained by dissolving the copper foil part from the copper-clad laminate by etching. to make. The surface-treated copper foil of the present invention may be any one of electrolytic copper foil and rolled copper foil. In addition, the above-mentioned multilayer board T1 is a multilayer board for reflow heat resistance test. In the actual circuit board, there are parts where the copper foil is dissolved and parts where the copper foil is insoluble, and a circuit pattern is formed.

In a general reflow test, two or more resin base materials B1 and B2 are laminated to prepare a test piece T1, and heating is performed to evaluate whether or not interfacial peeling occurs. At this time, the bonding interface S of the first resin base material B1 and the second resin base material B2 has fine voids C due to defects caused during pressing and the like (this void is hereinafter referred to as "cracks"). When the test piece is heated to the reflow temperature region (example: 260°C), the low molecular weight components in the first resin base material B1 and the second resin base material B2 volatilize as a gas. As shown in Fig. 3(a) and Fig. 4(a), the volatilized gas is stored in the crack C to generate an expansion force F1, and generates a shear force F2 that causes the crack C to propagate (expand the crack C). In addition, the propagation of the crack C acts along the direction of the shear bonding interface S, thereby preventing the friction (static friction) F3 of the first resin substrate B1 from deviating from the second resin substrate B2 caused by shear on the first resin substrate The bonding interface S between B1 and the second resin substrate B2 is generated, and the propagation of the crack C is suppressed. Here, the inventors found that the shear energy of the shear force F2 generated at the bonding interface S due to the expansion force F1 of the gas accumulated in the gap C of the bonding interface S is set to Es, and the bonding When the frictional energy of the frictional force F3 generated by the interface S is set to Ef, if the relationship of the following formula (1) holds, as shown in Figure 3 (a) to (c), the first resin substrate B1 and the The propagation of the crack C on the bonding interface S of the two resin substrates B2 can inhibit peeling at the interface formed between the two resin substrates B1 and B2.

The shear energy Es<the friction energy Ef. . . (1)

Here, the "shearing force F2" is the force resulting from the expansion force of the gas generated from the resin substrates B1 and B2, and the force acting in the direction parallel to the bonding interface S to propagate the crack C, "shear energy Es "" is the work (energy) obtained by multiplying the shearing force F2 by the distance of the shearing force F2. "Friction force F3" is the shearing force along the bonding interface S between the first resin substrate B1 and the second resin substrate B2 The force acting in the opposite direction of F2 to inhibit the propagation of the crack C. "Friction energy Ef" is the distance between the bonding interface S between the first resin substrate B1 and the second resin substrate B2 applied by the shear force F2 multiplied by the friction force F3 The work (energy) obtained (refer to Figure 3(a)).

On the other hand, if the shear energy Es in the bonding interface S is greater than the friction energy Ef, as shown in Figures 4(a) to (c), the friction force F3 in the bonding interface S is less than the shear force F2, so the first The bonding interface S of the resin substrate B1 and the second resin substrate B2 deviates and the crack C continues to propagate, eventually causing interface peeling.

As a result of in-depth research, the inventor found that as shown in Figures 3 and 4, the main factor that inhibits the propagation of gas-generated cracks C is caused by the bonding interface S between the first resin substrate B1 and the second resin substrate B2. The frictional force F3 (or frictional energy Ef), in particular, has a greater effect on the interface height H of the bonding interface S between the first resin substrate B1 and the second resin substrate B2. That is, if the interface height H is high, the distance (area) of the interface formed between the resin substrate and the resin substrate under the action of shearing force increases, thereby increasing the frictional energy. As a result, the propagation of cracks can be suppressed when the heating causes gas generation. . In addition, the copper foil with the higher interface height H has a higher fixing effect, so there is a tendency for the resin to adhere to the copper foil with high adhesion.

The desired characteristics are obtained by setting the interface height H of the bonding interface S of the first resin substrate B1 and the second resin substrate B2 to 0.15 to 0.85 μm, and it is preferable to set the interface height H to the range of 0.18 to 0.50 μm. By setting the interface height H in the above range, it is possible to achieve both reflow heat resistance and transmission characteristics at a high level. When the interface height H is less than 0.15 μm, the reflow heat resistance decreases. This is because when the low molecular weight components in the resin substrates B1 and B2 vaporize during the reflow test, the frictional energy Ef at the bonding interface S of the first resin substrate B1 and the second resin substrate B2 is small, so it cannot Withstand the shearing force F2 due to the expansion force F1 of the gas and peel off. On the other hand, if the interface height H is greater than 0.85 μm, the surface profile of the copper foil before etching becomes too high, and therefore the transmission loss becomes larger. In addition, the adhesion interface S between the first resin substrate B1 and the second resin substrate B2 was investigated in detail, and the results confirmed that the shape of the adhesion interface S between the first resin substrate B1 and the second resin substrate B2 was not a surface Process the perfect copy of the roughened layer of copper foil. The reason is that the roots of the roughened particles of the copper foil and the gaps where the roughened particles meet each other may not be sufficiently filled with resin. Therefore, in order to ensure sufficient reflow heat resistance, it is necessary to use copper foil that can obtain the above-mentioned interface height H. In particular, it is more preferable to set the interface height H to the range of 0.20 to 0.25 μm because it can achieve both reflow heat resistance and transmission characteristics at a higher level.

In addition, as a method to quantify the surface unevenness of copper foil, it is known to use a contact roughness meter to measure the ten-point average roughness Rz, but the diameter of the stylus of a common contact roughness meter is 2.0μm. According to the invention, it is not applicable to accurately measure the surface condition including the fine uneven shape (interface) height of 1 μm or less. In addition, another problem of Rz is that it is affected by the fluctuation of the original foil with an interval of tens of μm before the roughening treatment. As shown in this patent for example When it is necessary to quantify only the unevenness of the resin-resin interface in the cross-sectional image with a width of 2.54μm, Rz is affected by both the undulation of the original foil and the roughened unevenness, so it is not suitable as an index. In addition, the method of measuring the interface height H will be described later.

In addition, the dielectric constant of the first resin substrate of the copper-clad laminate formed by laminating and bonding with the surface-treated copper foil of the present invention is in the range of 2.6 to 4.0. The first resin substrate with a dielectric constant of less than 2.6 is usually a difficult-to-adhesive resin substrate with fewer functional groups. In the present invention, where the profile of the surface-treated copper foil is relatively low, the difference between the copper foil and the first resin substrate The peel strength on the bonding interface is easily reduced. In addition, if the dielectric constant is greater than 4.0, the dielectric constant is high, so the dielectric loss increases, and as a result, the transmission loss increases. From this viewpoint, the dielectric constant of the first resin substrate is more preferably in the range of 3.0 to 3.9.

As the first resin substrate, resin compositions from polyphenylene ether resins, polyphenylene ether resins containing polystyrene-based polymers, polymers or copolymers containing triallyl cyanurate, and acrylic resins can be used. Acrylic or acrylic modified epoxy resin composition, phenolic butadiene polymer, diallyl phthalate resin, divinylbenzene resin, polyfunctional methacrylic resin, unsaturated Polyester resin, polybutadiene resin, styrene-butadiene, cross-linked polymer of styrene-butadiene and styrene-butadiene, polytetrafluoroethylene and other insulating resins.

Examples of the second resin base material include resin base materials made of the same insulating resin as the first resin base material, and resin impregnated materials such as prepregs in which the insulating resin is impregnated in a skeleton material such as glass fiber or aramid fiber. Wait.

In addition, the number of concavities and convexities in the bonding interface S of the first resin substrate B1 and the second resin substrate B2 of the surface-treated copper foil of the present invention is within a width of 2.54 μm The medium number is 11 to 30, more preferably 15 to 25. If the number of concavities and convexities of the bonding interface S is in the range of 11 to 30, the friction energy Ef of the bonding interface S of the first resin substrate B1 and the second resin substrate B2 is higher, and therefore the reflow heat resistance is improved. On the other hand, if the number of concavities and convexities of the bonding interface S is less than 11, the friction energy Ef on the bonding interface S is low, and therefore the reflow heat resistance is reduced. On the other hand, if the number of concavities and convexities of the bonding interface S is more than 30, the cracks C generated between adjacent concavities and convexities are likely to continue to propagate, and the reflow heat resistance is reduced.

Here, as a method of quantifying the unevenness of the copper foil surface, it is known that the surface area is measured using a non-contact roughness meter such as a laser microscope. However, when using a laser microscope, the diameter of the laser is about 0.4μm, so there is a problem that it is impossible to detect fine irregularities with a width of 0.4μm or less. As described above, the reflow heat resistance is affected by the number of irregularities. Therefore, in the present invention, the number of irregularities in the bonding interface can be managed through cross-sectional observation that can discriminate fine irregularities with a width of 0.4 μm or less. In addition, the method of measuring the number of irregularities in the bonding interface S will be described later.

In addition, the interface inclination angle θ in the bonding interface S of the first resin substrate B1 and the second resin substrate B2 of the surface-treated copper foil of the present invention is preferably 15° to 85°, more preferably 20° to 70° . When the interface inclination angle θ is less than 15°, the slope of the crack propagation path changes smoothly during the reflow test, so the friction energy Ef at the bonding interface S decreases, and the reflow heat resistance tends to decrease. On the other hand, when the interface inclination angle θ is greater than 85°, the crack C does not propagate along the bonding interface S of the first resin substrate B1 and the second resin substrate B2, so there is a tendency for the reflow heat resistance to decrease. In addition, the interface tilt angle θ is defined as follows. That is, using a scanning electron microscope, through the SEM image (width 2.54μm range) Observe the bonding interface S between the first resin substrate (resin core layer) B1 and the second resin substrate (prepreg layer) B2, and divide the unevenness in the two-half of the interface height H The average value of the angle between the tangent line m drawn at a height position and the baseline BL2 is defined as the interface tilt angle θ (refer to Figure 1(b)).

Here, an example of a method of manufacturing copper foil satisfying the above-mentioned characteristics is shown.

In the bonding interface S of the first resin base material B1 and the second resin base material B2, as a surface treatment method for obtaining a copper foil with a correct interface height H, a roughening treatment is preferably used. The roughening treatment is preferably performed by combining the roughening plating treatment 1 and the roughening plating treatment 2 described below, for example.

(Roughening plating treatment 1)

The roughening electroplating treatment 1 is a method of forming roughened particles on the copper foil, specifically using a copper sulfate plating bath for electroplating with high current density. Various additives can be added to the copper sulfate plating bath. As a result of intensive research, the inventor found that the following factors will affect the shape of the interface between the resins, and found that by setting these conditions correctly, the reflow heat resistance, transmission characteristics, and adhesion of the effects of the present invention can be met at a high level. 3 required characteristics of sex.

It has been confirmed that when the current density is increased, the interface height H of the bonding interface S between the resin base materials B1 and B2 becomes higher. As an additive for making roughening fine, for example, as described in Japanese Patent No. 4629969, adding Mo to a roughening plating bath is known. However, when the copper foil with the interface height H of the bonding interface is 1.0μm is produced by the roughening treatment using the roughening plating bath of the past with the addition of Mo, in most cases the number of unevenness of the bonding interface exceeds 30 per 2.54μm width Or if it is 10 or less, sufficient reflow heat resistance cannot be obtained.

In contrast to this, as a result of intensive research of the present invention, it was found that in addition to adding Mo to the plating bath of roughening plating treatment 1, by adding any metal or compound of titanium (Ti), palladium (V) and zirconium (Zr), even The interface height H is 1.0 μm or less, and the number of concavities and convexities of the bonding interface can also be controlled within an appropriate range (11 to 30 per 2.54 μm width). The principle is not clear. It is speculated that the metal or compound with a different precipitation potential from Mo affects the frequency of nucleation of roughening plating, resulting in a change in the number of roughened particles produced. In addition, as other additives that control the number of concavities and convexities of the bonding interface within an appropriate range, experiments have confirmed that it can be MPS (4,4'-thiobisphenylthiol (mercaptophenyl sulfide)), SPS (double (3-sulfopropyl) disulfide).

(Roughening plating treatment 2)

The roughening plating treatment 2 performs smooth coating plating on the copper foil surface-treated by the roughening treatment plating 1 in order to prevent the roughening particles from falling off. As an example, it is performed by a copper sulfate plating bath or the like.

Furthermore, in the surface-treated copper foil of the present invention, as the surface-treated layer provided on the bonding surface of the first resin substrate, for example, one formed by electrodeposition using roughened particles on a copper foil substrate In the case of forming a roughened layer on the surface of the fine uneven surface, or in the case of forming a silane coupling agent layer on the roughened layer.

In addition, as a method of forming the silane coupling agent layer, for example, the following method can be cited, that is, directly or indirectly via an intermediate layer on the uneven surface of the roughened layer of the surface-treated copper foil, and then air-dry the silane coupling agent solution. Dry) or heat and dry to form. The coating coupling agent layer is dried as long as the water evaporates, and the effect of the present invention can be fully exerted, but it is dried by heating at 50 to 180℃ It is preferable to promote the reaction between the silane coupling agent and the copper foil later.

The silane coupling agent layer preferably contains epoxy-based silane, amino-based silane, vinyl-based silane, methacrylic-based silane, acrylic-based silane, styrene-based silane, urea-based silane, mercapto-based silane, sulfide-based silane, and isocyanate-based silane. Any one or more of silanes.

As another embodiment, it is more preferable to have an intermediate layer of at least one layer selected from a Ni-containing base layer, a Zn-containing heat-resistant treatment layer, and a Cr-containing rust-proof treatment layer between the surface-treated copper foil and the silane coupling agent layer.

The nickel (Ni)-containing base layer is preferably formed when copper (Cu) in the copper foil matrix and the roughened layer diffuses to the side of the first resin substrate and copper corrosion occurs and the adhesion is reduced. Between the layer and the silane coupling agent layer. The Ni-containing base layer contains at least one of nickel (Ni), nickel (Ni)-phosphorus (P), and nickel (Ni)-zinc (Zn). Among them, nickel-phosphorus is preferred from the viewpoint of being able to suppress nickel residue during copper foil etching performed when circuit wiring is formed.

The zinc (Zn)-containing heat-resistant treatment layer is preferably formed when it is necessary to further improve the heat resistance. The heat-resistant treatment layer is preferably formed of, for example, zinc or a zinc-containing alloy, which is selected from zinc (Zn)-tin (Sn), zinc (Zn)-nickel (Ni), zinc (Zn)-cobalt (Co), At least one zinc-containing alloy selected from zinc (Zn)-copper (Cu), zinc (Zn)-chromium (Cr), and zinc (Zn)-palladium (V). Among the above, zinc-palladium is particularly preferred from the viewpoint of suppressing undercut during etching performed when forming circuit wiring. In addition, the "heat resistance" mentioned here refers to the property that the adhesion strength between the surface-treated copper foil and the resin substrate is not easily reduced after the surface-treated copper foil laminated resin substrate is heated to harden the resin. Different characteristics from reflow heat resistance.

The Cr-containing antirust treatment layer is preferably formed when it is necessary to further improve the corrosion resistance. Examples of the anti-rust treatment layer include a chromium layer formed by chromium plating and a chromate layer formed by chromate treatment.

When all the three layers of the above-mentioned base layer, heat-resistant treatment layer and anti-rust treatment layer are formed, it is preferable to form on the roughened layer in this order. In addition, only one or two layers can be formed according to the application or the characteristics of the purpose. .

In addition, the surface-treated copper foil of the present invention is suitable for manufacturing copper-clad laminates or printed wiring boards. The copper-clad laminate is manufactured by laminating and bonding the surface-treated copper foil and the first resin substrate (insulating substrate) so that the bonding surface of the surface-treated copper foil faces the first resin substrate.

When manufacturing a copper-clad laminate, it can be manufactured by heating and pressing a surface-treated copper foil with a silane coupling agent layer and an insulating substrate to adhere them. In addition, a silane coupling agent is coated on an insulating substrate, and a copper-clad laminate is produced by heating and pressing it with a copper foil with an anti-rust treatment layer on the outermost surface to make a copper-clad laminate. The same effect.

〔Production of surface treated copper foil〕

(1) The formation process of the roughened layer

The electrodeposition of roughened particles is used to form a roughened layer with fine uneven surface on the copper foil substrate.

(2) The formation process of the base layer

If necessary, a Ni-containing base layer is formed on the roughened layer.

(3) Formation process of heat-resistant treatment layer

A Zn-containing heat-resistant treatment layer is formed on the roughened layer or the base layer as needed.

(4) Formation process of anti-rust treatment layer

If necessary, immerse it in an aqueous solution containing Cr compounds with a pH value of less than 3.5, and perform chromium electroplating treatment with a current density of 0.3A/dm ² or more on the roughened layer or on the roughened layer as required An anti-rust treatment layer is formed on the base layer and/or heat-resistant treatment layer.

(5) The formation process of the silane coupling agent layer

A silane coupling agent layer is formed directly on the roughened layer or indirectly via an intermediate layer forming at least one of the base layer, the heat-resistant treatment layer, and the rust-proof treatment layer.

〔Manufacturing of Copper Clad Laminate〕

The copper-clad laminate of this embodiment is manufactured through the following process.

(1) Production of surface treated copper foil

According to the above (1) to (5), the surface treatment copper foil is produced.

(2) Manufacturing (laminating) process of copper clad laminate

The surface-treated copper foil produced above and the first resin substrate (insulating substrate) are superimposed so that the surface of the silane coupling agent layer constituting the surface-treated copper foil faces the bonding surface of the first resin substrate (insulating substrate) , By heating and pressurizing treatment to make the two adhere, thereby manufacturing copper-clad laminate.

In addition, the above description is merely an example of the embodiment of the present invention, and various methods can be adopted without departing from the scope of the main content of the present invention.

Example

[Example 1]

The surface treatment was performed on a copper foil substrate with a thickness of 18 μm without roughening (surface roughness Rz: about 1.1 μm) under the following conditions to produce a surface-treated copper foil.

(1) Formation of roughened layer

When the surface of the copper foil substrate is roughened, the following roughening plating treatments 1 and 2 are sequentially performed to form a roughened layer.

(Roughening plating treatment 1)

It was implemented under the conditions shown in Table 1.

(Roughening plating treatment 2)

Copper sulfate: copper concentration 40 to 63g/L

Sulfuric acid: 135 to 155g/L

Liquid temperature: 57 to 68°C

Current density: 7 to 13A/dm ²

Time: 1 second to 2 minutes

(2) Formation of Ni-containing base layer

After forming a roughened layer on the surface of the copper foil base, electroplating is performed on the roughened layer under the Ni plating conditions shown below to form a base layer (Ni adhesion amount 0.06 mg/dm ² ).

<Ni plating conditions>

Nickel sulfate: nickel concentration 5.0g/L

Ammonium persulfate: 40.0g/L

Boric acid: 28.5g/L

Current density: 1.5A/dm ²

pH value: 3.8

Temperature: 28.5℃

Time: 1 second to 2 minutes

(3) Formation of Zn-containing heat-resistant treatment layer

After the base layer was formed, electroplating was performed on the base layer under the Zn plating conditions shown below to form a heat-resistant treatment layer (Zn adhesion amount: 0.05 mg/dm ² ).

<Zn plating conditions>

Zinc sulfate heptahydrate: 1 to 30g/L

Sodium hydroxide: 10 to 300g/L

Current density: 0.1 to 10A/dm ²

Temperature: 5 to 60°C

Time: 1 second to 2 minutes

(4) Formation of Cr-containing anti-rust treatment layer

After the heat-resistant treatment layer was formed, the heat-resistant treatment layer was treated under the chromium plating conditions shown below to form a rust preventive treatment layer (Cr adhesion amount: 0.02 mg/dm ² ).

<Chrome plating conditions>

Chromic anhydride (CrO ₃ ): 2.5g/L

pH value: 2.5

Current density: 0.5A/dm ²

Temperature: 15 to 45°C

Time: 1 second to 2 minutes

(5) Formation of silane coupling agent layer

After the rust preventive treatment layer was formed, the silane coupling treatment was performed on the rust preventive treatment layer with the silane treatment liquid and treatment conditions shown below to form a silane coupling agent layer with the adhesion amount shown in Table 2. In addition, the adhesion amount of the metal constituting each layer was measured by quantitative analysis using a fluorescent X-ray analyzer (manufactured by RIGAKU: ZSX Primus, analysis diameter: Φ35 mm).

<Silane treatment liquid and treatment conditions>

Silane type: γ-methacryloxypropyl trimethoxysilane

Silane concentration: 0.1 to 10g/L

Liquid temperature: 20 to 50°C

[Example 2] to [Example 20]

The roughening plating treatment 1 was performed under the conditions shown in Table 1, and the other treatments were performed under the same conditions as in Example 1.

[Comparative Example 1] to [Comparative Example 17]

The roughening plating treatment 1 was performed under the conditions shown in Table 1, and the other treatments were performed under the same conditions as in Example 1.

(Characteristic evaluation of test piece)

Various measurements and evaluations were performed on each test piece, and the results are shown in Table 2.

(1) Measurement of the interface height H of the bonding interface between the first resin substrate and the second resin substrate

The measurement of the interface height H of the bonding interface between the first resin substrate and the second resin substrate is performed according to the following steps. First, the surface-treated copper foil M (M1) of the present invention is laminated on both sides of the first resin substrate B1, and pressed under the recommended pressing conditions for each resin substrate to produce a copper-clad laminate P (Figure 5(a)) . As the recommended pressing conditions, for example, if the first resin substrate B1 is R-5670 resin manufactured by Panasonic Corporation, temperature: 200° C., pressing pressure: 2.5 MPa, and pressing time: 180 minutes. Then, the pressed copper-clad laminate P is dried. In this embodiment, the drying treatment is performed under the conditions of 150°C×80 minutes. The copper-clad laminate P was etched under the following etching conditions A, and all the copper foil portions M1 were dissolved from the copper-clad laminate P to form the first resin substrate B1 (resin core The state of the board) (Figure 5(b)). Laminate an unused second resin substrate (such as a prepreg layer) B2 on the surface of the first resin substrate (resin core layer) B1 after etching (Figure 5(c)), and press it under the recommended pressing conditions , Make a test piece (multilayer board) T1 (Figure 5(d)).

Next, a scanning electron microscope (SEM: Hitachi, Ltd.: SU8020) was used to observe the cross-section of each test piece T1 processed by an ion milling device (Hitachi, Ltd.: IM4000). The interface height H of the bonding interface S between the material B1 and the second resin substrate B2 was measured. First, the observation magnification is enlarged to 200 times (the actual width of the field of view in the image of this patent is 63.5μm), and the first resin substrate (resin core layer) B1 and the second resin substrate (pre-impregnated Blank layer) The extension direction of the bonding interface S of B2 is aligned with the horizontal direction of the screen within ±1°, and then the observation magnification is expanded to 10,000 times (the actual width of the field of view in the image in this patent is 12.7μm), The bottom position of the first concave portion having the lowest point position, that is, the bottom position among the concavities and convexities forming the bonding interface S, which is mapped into the SEM image, is set as point A. Then, the first concave portion and the first concave portion are removed. 1 The bottom position of the second recess with the lowest point position of the remaining recesses of the adjacent recesses, that is, the bottom position, is set as point B, and then the line connecting point A and point B is set as the baseline BL1 (Figure 1(a) ). Then, in the SEM image of 50,000 times (the actual width of the field of view in the image of this patent is 2.54μm), the baseline BL2 is drawn parallel to the baseline BL1, and the first resin substrate (resin core) is formed by passing it at any position. Board layer) B1 and the second resin substrate (prepreg layer) B2 in the concavity and convexity of the bonding interface S has the lowest point position, that is, the bottom position of the bottom position of the bottom position of the third recess, the vertical direction to the farthest from the baseline BL2 The distance between the apex of the convex part is measured as the boundary Surface height H (Figure 1(b)). In this example, the height of each interface was measured in the field of view at 5 locations, and the average value was used as the measurement of the interface height H.

In addition, when the first resin substrate (resin core layer) B1 and the second resin substrate (prepreg layer) B2 are the same resin substrate, and it is difficult to see the bonding interface S in SEM observation, the following Etching condition B is to perform etching to etch the first resin substrate (resin core layer) B1 and the second resin substrate (prepreg layer) B2 so as to be easy to see.

<Etching condition A>

Copper chloride concentration: 1.2 to 2.5mol/L

Hydrochloric acid: 2.9mol/L

Liquid temperature: 30 to 45°C

<Etching condition B>

Distilled water: 80cc

Ammonia: 7cc

Hydrogen peroxide water: 5cc

Temperature: about 25℃

Etching time: 4 to 6 seconds

(2) Measurement of contact roughness Rz and Ra

In accordance with JIS B 0601: 1994, a contact surface roughness measuring machine (SE1700 manufactured by Kosaka Laboratory Co., Ltd.) was used to measure the ten-point average roughness Rz and the arithmetic average roughness Ra on the surface of the produced copper foil.

(3) Method for measuring the number of concavities and convexities of the bonding interface between the first resin substrate and the second resin substrate

And pass through the first resin substrate (resin core layer) B1 and the second resin substrate (Prepreg layer) The measurement method of the interface height H of the bonding interface S of B2 is also observed. The interface S is within the width of 2.54μm (the actual width of the field of view in the image of this patent is 2.54μm). A resin substrate (resin core layer) B1 and a second resin substrate (prepreg layer) B2 of the bonding interface S of the uneven slope and the baseline BL2 parallel to the number of points measured (refer to Figure 2), the measurement The number is used as the number of concavities and convexities of the bonding interface S between the first resin substrate (resin core layer) B1 and the second resin substrate (prepreg layer) B2. The present invention measures the number of concavities and convexities of each bonding interface S in a visual field of 5 locations, and uses the average value as the number of concavities and convexities of the bonding interface S.

(4) Method for measuring the inclination angle of the interface between the first resin substrate and the second resin substrate

Use a scanning electron microscope to compare the first resin substrate (resin core layer) B1 and the second resin substrate (prepreg layer) B2 through the SEM image taken at a magnification of 50,000 times (width of 2.54μm) Observe the bonding interface S, draw a tangent line m at a position that is half the height of the interface height H in each unevenness. The interface inclination angle θ is the angle formed by the tangent line m and the baseline BL2. In this embodiment, the tangent line is aligned at 5 locations. The angle between m and the baseline BL2 is measured, and the average value is obtained as the interface tilt angle θ. In addition, the specific method of measuring the interface inclination angle θ is shown in Fig. 8(a) and Fig. 8(b). The angles θ1 and θ2 formed by the tangent line m1, m2 and the base line BL2 drawn on each unevenness One-half of the height of the height H (through the vertical distance to the vertex of the convex part furthest from the baseline BL2 (interface height H), draw a line parallel to BL2 BL3, BL3 and the contour line of the bump The angle between the tangent line m of the intersection position) and the baseline BL2 is measured. Figure 8(a) shows the interface tilt as a reference When the angle θ1 is within the appropriate range (70°) of the present invention, Fig. 8(b) is used as a reference to show the case where the interface tilt angle θ2 is outside the appropriate range (100°) of the present invention.

(5) Evaluation of transmission characteristics (measurement of transmission loss under high frequency)

After processing each sample as a material and forming a transmission path using a microstrip line, the transmission loss is measured with a network analyzer, and the transmission characteristics are evaluated based on the measured transmission loss value. The produced microstrip line has a characteristic impedance of 50Ω. For example, when the first resin base material is R-5670, set the thickness of copper foil: 18μm, resin thickness: 0.2mm, width: 500μm, and length: 200mm. As the first resin substrate, the resin substrate shown in Table 2 was used. Regarding the transmission characteristics, at 20GHz, the case where the transmission loss is -6.2dB or more is judged as "◎ (pass)", the case of less than -6.2dB and -6.5dB or more is judged as "○ (pass)", and then the case is insufficient The case of -6.5dB is judged as "× (unqualified)". In addition, at 70GHz, the case where the transmission loss is -20.6dB or more is judged as "◎ (pass)", the case of less than -20.6dB and -22.0dB or more is judged as "○ (pass)", and the case is less than -22.0dB And the case of -24.0dB or more is judged as "△ (pass)", and the case of less than -24.0dB is judged as "× (unqualified)".

(6) Evaluation of the adhesion (peel strength) of the surface-treated copper foil to the first resin substrate

The adhesion strength (peel strength) of the surface-treated copper foil to the first resin substrate was measured, and the adhesion of the surface-treated copper foil to the first resin substrate was evaluated based on the measured value. As the first resin substrate, the substrate shown in Table 2 was used. The test piece was pressed under the recommended pressing conditions of each first resin substrate. The surface treatment copper foil After lamination and bonding (bonding) with the first resin substrate, the test piece is etched into a circuit wiring with a width of 10 mm, and the first resin substrate side is fixed to the stainless steel plate with double-sided tape. The tensile tester (Tensilon tester ) (Manufactured by Toyo Seiki Seisakusho Co., Ltd.), the circuit wiring was peeled off at a speed of 50 mm/min in a 90-degree direction to obtain the adhesion strength. Regarding the adhesion, the adhesion strength (peel strength) of less than 0.4 kN/m is evaluated as "× (unacceptable)", 0.4 kN/m or more and less than 0.5 kN/m is evaluated as "△ (acceptable)", and 0.5 kN/m or more and less than 0.6 kN/m is evaluated as "○ (pass)", and 0.6 kN/m or more is evaluated as "◎ (pass)".

(7) Reflow heat resistance

First, the method of making the test piece T2 for the reflow heat resistance test will be described. First, a copper-clad laminate P with surface-treated copper foil M1 laminated on both sides of the first resin substrate B1 is produced (Figure 6(a)). Next, the copper-clad laminate P is etched with a copper (II) chloride solution or the like to dissolve the entire copper foil portion M1 (FIG. 6(b)). By laminating and bonding the second resin substrate (prepreg layer) B2 and copper foil M2 on both sides of the etched first resin substrate (resin core layer) B1 (Figure 6(c)), it is made for alignment Test piece T2 for the measurement of reflow heat resistance (Figure 6(d)). Next, the produced test piece T2 was passed through a reflow furnace, and was passed through under the condition of heating at a maximum temperature of 260°C for 10 seconds. When it was repeatedly passed through the reflow furnace under this condition, the test piece that did not cause interlayer peeling between the resin core layer B1 and the prepreg layer B2 after 15 passes was evaluated as "◎ (pass)". The test piece that passed 13 to 14 times with interlayer peeling was evaluated as "○ (pass)", the test piece that passed 10 to 12 times with interlayer peeling was evaluated as "△ (pass)", and then the number of passes was insufficient Delamination occurred 10 times The test piece was evaluated as "× (unacceptable)".

Furthermore, this embodiment comprehensively evaluates the performance based on the results of the evaluation of the transmission characteristics, adhesion, and reflow heat resistance through the above (4) to (6). Regarding this comprehensive evaluation, in the evaluation of adhesion, reflow heat resistance, transmission characteristics (20GHz), and transmission characteristics (70GHz), the case where there are more than three ◎ and the remaining ○ is evaluated as "◎ (pass)", and ◎ If the number is 0 to 2 and the remainder is ○, the case is evaluated as "○ (pass)", the case of △ 1 to 4 without × is evaluated as "△ (pass)", and then the case with more than 1 × is evaluated It is evaluated as "× (unqualified)".

According to Table 2, it can be seen that the adhesion, transmission characteristics and reflow heat resistance of the surface-treated copper foils of Examples 1 to 20 and the first resin substrate (insulating substrate) have all reached the acceptable level. On the other hand, at least one of the dielectric constant of the first resin substrate of Comparative Examples 1 to 17, the interface height H of the bonding interface, and the number of concavities and convexities is outside the scope of the present invention, and therefore, sufficient characteristics cannot be obtained. Fig. 7 is a comparison of Examples 1 to 20 (black squares in Fig. 7) and Comparative Examples 1 to 17 (white triangles in Fig. 7), based on the interface height of the bonding interface between the first resin substrate and the second resin substrate H is the horizontal axis, and the number of concavities and convexities existing in the bonding interface is the vertical axis when drawing. It can be seen from FIG. 7 that the interface height of the bonding interface of Examples 1 to 20 is in the range of 0.15 to 0.85 μm, and the number of concavities and convexities existing in the bonding interface is in the range of 11 to 30 per 2.54 μm width.

[Industrial availability]

The present invention can provide a surface-treated copper foil, which is suitable for high-performance and high-functional copper-clad laminates that can support high-frequency information communication equipment that can support high-speed transmission of large-capacity information. Or printed wiring board, in the copper-clad laminate or printed wiring board made of the surface-treated copper foil, it can meet the high level of the resin substrate with low dielectric constant and dielectric loss tangent and excellent dielectric properties. Full adhesion, reflow heat resistance and transmission characteristics. Furthermore, it is possible to provide a copper-clad laminate or printed wiring board manufactured using this surface-treated copper foil.

Claims (20)

A surface-treated copper foil, which is used to form a copper-clad laminate by lamination and bonding with a first resin substrate with a dielectric constant of 2.6 to 4.0, and is characterized in that: the bonding surface with the first resin substrate has The surface treatment layer that satisfies the condition 1 shown below: Condition 1: When the second resin substrate is laminated and bonded on the surface of the first resin substrate obtained by dissolving the copper foil part from the copper-clad laminate by etching The interface height of the bonding interface between the first resin substrate and the second resin substrate is 0.15 to 0.85 μm, and the number of concavities and convexities existing in the bonding interface is 11 to 30 per 2.54 μm width. The surface-treated copper foil described in the first item of the scope of patent application, wherein the number of concavities and convexities existing in the bonding interface is 15 to 25 per 2.54 μm width. The surface-treated copper foil described in item 1 or 2 of the scope of patent application, wherein the interface height of the bonding interface is 0.18 to 0.50 μm. The surface-treated copper foil described in item 3 of the scope of patent application, wherein the interface height of the bonding interface is 0.20 to 0.25 μm. The surface-treated copper foil described in item 1 or item 2 of the scope of patent application, wherein the dielectric constant of the first resin substrate is 3.0 to 3.9. The surface-treated copper foil described in item 3 of the scope of patent application, wherein the dielectric constant of the first resin substrate is 3.0 to 3.9. The surface-treated copper foil described in item 1 or item 2 of the scope of patent application, wherein the interface inclination angle θ existing at the bonding interface is 15° to 85°. The surface-treated copper foil as described in item 3 of the scope of patent application, in which there are The inclination angle θ of the interface at the bonding interface is 15° to 85°. The surface-treated copper foil described in item 5 of the scope of patent application, wherein the interface inclination angle θ existing at the bonding interface is 15° to 85°. A copper-clad laminate, which combines the surface-treated copper foil described in any one of items 1 to 9 in the scope of the patent application and the first resin substrate with the bonding surface of the surface-treated copper foil and the first It is formed by laminating and bonding the resin substrates facing each other. A printed wiring board using the surface-treated copper foil described in any one of items 1 to 9 in the scope of patent application. A printed wiring board, which has one or more resin laminates formed by laminating and bonding a first resin substrate and a second resin substrate with a dielectric constant of 2.6 to 4.0, and is characterized in that: The interface height of the bonding interface between the resin substrate and the second resin substrate is 0.15 to 0.85 μm, and the number of concavities and convexities existing in the bonding interface is 11 to 30 per 2.54 μm width. The printed wiring board described in item 12 of the scope of patent application, wherein the number of concavities and convexities existing in the bonding interface is 15 to 25 per 2.54 μm width. The printed wiring board described in item 12 or 13 of the scope of patent application, wherein the interface height of the bonding interface is 0.18 to 0.50 μm. The printed wiring board described in item 14 of the scope of patent application, wherein the interface height of the bonding interface is 0.20 to 0.25 μm. The printed wiring board according to item 12 or 13 of the scope of patent application, wherein the dielectric constant of the first resin substrate is 3.0 to 3.9. The printed wiring board according to claim 14, wherein the dielectric constant of the first resin substrate is 3.0 to 3.9. The printed wiring board described in item 12 or 13 of the scope of patent application, wherein the interface inclination angle θ existing in the bonding interface is 15° to 85°. In the printed wiring board described in item 14 of the scope of patent application, the inclination angle θ of the interface existing at the bonding interface is 15° to 85°. The printed wiring board described in item 16 of the scope of patent application, wherein the interface inclination angle θ existing in the bonding interface is 15° to 85°.

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