JP4826569B2 - Metal plate material for printed wiring board and manufacturing method thereof - Google Patents

Description

  The present invention relates to a metal plate material for a printed wiring board suitable for a printed wiring board for a relatively large current capacity, such as a printed wiring board for automobiles, and a method for manufacturing the same.

  As a typical field that is required to have a relatively large current capacity, there is a so-called automobile electronics field, and the use of automobiles in electronics has been increasingly developed in recent years. Among them, for example, in a junction box, a bus bar is generally used for energizing a large current. The distribution structure such as this bus bar has the feature that it has good durability against environmental changes such as severe temperature and humidity, but on the other hand, there are significant spatial restrictions and the design is hindered by the restrictions. The degree of freedom tends to be low. Therefore, it is desired to make the entire wiring structure of the junction box into a printed wiring board. However, in order to realize this, a highly durable and reliable printed wiring board that does not cause disconnection or wiring deterioration even if a relatively large current is continuously applied in a severe operating environment. It is strongly requested to use it.

  A printed wiring board is manufactured by processing a so-called copper-clad substrate, which is formed by laminating a copper foil or a copper thin plate on the surface of a plate-like or sheet-like glass epoxy substrate. The copper-clad board is made of, for example, a flame-retardant resin substrate for printed wiring boards made of a composite material of glass fiber and epoxy resin, such as FR4 (Frame Regentant Type 4), and a copper plate material having a thickness of several tens to 100 μm In order to make this bonding more reliable, a roughening treatment is applied to the entire surface of the copper plate material. It is desirable to apply.

As a typical example of such a conventional roughening process, there is a technique proposed by Japanese Patent Application Laid-Open No. 2004-200557 (Patent Document 1).
This is because the surface of a relatively thick metal plate having a thickness of 0.1 mm or more is etched entirely in the manner of so-called half-etching, and averaged along the grain boundaries of the metal constituting the metal plate. An average particle size of 0.1 μm to 10 μm is formed by electrodeposition using the fact that a first roughened surface comprising a large number of convex portions having a particle size of about 1 μm to 30 μm is formed and an electric field is concentrated along the grain boundary. The second roughened surface is formed by intensively adhering the fine particles along the grain boundary.

Japanese Patent Laid-Open No. 2004-200557

However, even with the technique proposed in Japanese Patent Application Laid-Open No. 2004-200557 as described above, for example, in a severe use environment such as in an engine room as in the case of a printed wiring board corresponding to a large current for automobiles. However, there is a problem that the durability of the bonding force between the resin base material and the metal plate material is not sufficient, and a circuit, a heat dissipation material, or the like formed by processing the metal plate material is peeled off.
That is, in the technique proposed in the above Japanese Patent Application Laid-Open No. 2004-200557, fine particles are appropriately concentrated and adhered along the grain boundaries of the metal material constituting the metal plate, Even in such a case, fine particles are not concentrated in the portion other than the vicinity of the grain boundary than the portion of the grain boundary (the density of the fine particles is not necessarily sufficient). Under extremely harsh usage environments such as automobile applications, the durability of bonding is insufficient, and metal plate materials may be peeled off or partially peeled off.

  In addition, for example, a thin rolled copper foil having a thickness of about 10 μm to less than 100 μm is subjected to a roughening treatment on the surface thereof, so that the durability and reliability of bonding with a resin base material such as a polyimide film base material is achieved. Various techniques have been proposed for increasing the image quality. However, since these techniques are suitable for rolled copper foil having a very thin thickness, it is practically difficult or impossible to apply to a thick metal plate having a thickness of 100 μm or more.

  The present invention has been made in view of such problems, and its purpose is to provide a resin substrate for a printed wiring board, even under extremely harsh environments such as temperature and humidity, such as a printed wiring board for automobiles. An object of the present invention is to provide a metal sheet for printed wiring board and a method for producing the same, which can maintain high durability and reliability for bonding between the metal sheet and the metal sheet for printed wiring board.

The first metal plate material for a printed wiring board according to the present invention is a groove provided on a rolled copper foil having a thickness of 100 μm or more at the thickest portion, which is bonded to a plate-shaped resin substrate for a printed wiring board. A metal plate material for a printed wiring board in which fine particles are adhered to the groove , and the groove has a ten-point average surface roughness of the surface on the surface of the rolled copper foil bonded to the resin substrate for the printed wiring board. are forms formed such that the Rz of 4.5 [mu] m or more ~ 6.5 [mu] m or less, and the fine particles in the particle diameter 1.2μm or more ~4.0μm less, the fine particles in the interior of the groove The ratio of the area to which the film adheres to the groove area is 3% or more and 60% or less, and the peel strength according to the T-peel method is 5.3 N / mm to 6.2 N / mm. It is said.

  The second metal plate material for a printed wiring board according to the present invention is the metal plate material for the first printed wiring board, wherein the fine particles are any one of Cu, Ni, Zn, Co, Fe, Mo, and W. It is characterized by comprising a material composed of a metal element or a material combining two or more metal elements.

  The third metal plate material for a printed wiring board according to the present invention is the above-described first or second metal plate material for a printed wiring board, wherein the particle size of the fine particles is 5% to 50% with respect to the value of Rz. It is characterized by being.

According to a fourth printed wiring board metal plate of the present invention, in any one of the first to third printed wiring board metal plates, the adhesion occupation area ratio of the fine particles to the entire surface of the printed wiring board metal plate However, it is characterized by being 60% to 95% of the total area of the metal sheet material for printed wiring boards.

The first method for producing a metal plate material for a printed wiring board according to the present invention has a thickness of 100 μm or more at the thickest portion bonded to a plate-shaped resin substrate for a printed wiring board , and rolled copper foil A method for producing a printed wiring board metal plate material in which fine particles are adhered to a groove provided in the printed wiring board, wherein the rolled copper foil is bonded to the printed wiring board resin substrate. A first roughening step of forming grooves on the surface to have a ten-point average surface roughness Rz of 4.5 μm or more to 6.5 μm or less, and the first rough surface The ratio of the area where fine particles having a particle size of 0.2 μm to 4.0 μm adhere to the inside of the groove to the surface of the groove is 3% to 60%. including a second roughened depositing as It is characterized by that.

  The second method for producing a metal plate material for a printed wiring board according to the present invention is the above-described first method for producing a metal plate material for a printed wiring board, wherein the second roughening step includes etching, shot blasting, and electric roughening. It is characterized by being performed by any one of plating or a combination of two or more.

  A third method for producing a metal sheet for printed wiring board according to the present invention is the first or second method for producing a metal sheet for printed wiring board, wherein the first roughening treatment and the second roughening are performed. After the treatment, it is further characterized in that a treatment combining any one or two or more of Ni plating, Zn plating, chromate treatment, and silane coupling treatment is performed.

  Moreover, as a metal plate material of the printed wiring board metal plate material itself, a copper plate material that is most often used is generally suitable. However, it is needless to say that the present invention is not limited to this. In addition, for example, the present invention can be applied to an aluminum plate. Furthermore, in recent years, a hybrid composite material having a high thermal conductivity in which a metal and an organic material are combined has been developed, and the same treatment can be applied to such a material.

  According to the present invention, the 10-point average surface roughness Rz of the surface of the metal plate material for a printed wiring board having a maximum thickness of 100 μm or more is 1.0 μm. Since grooves are formed so as to be 10 μm or less and fine particles having a particle diameter of 0.2 μm or more and 4.0 μm or less are adhered, the resin substrate for printed wiring board is a metal plate material for printed wiring board. In addition to three-dimensionally biting in the depth direction of the groove, the resin substrate for the printed wiring board bites into the irregularities on the surface due to the adhesion of the fine particles, resulting in extremely strong bonding. As a result, it becomes possible to maintain high durability and reliability with respect to the bonding between the printed wiring board resin substrate and the printed wiring board metal plate.

  In particular, by setting the particle size of the fine particles to a value of 5% to 50% with respect to the Rz value on the surface of the metal plate material for printed wiring boards, it is hindered due to the presence of fine particles in the vicinity of the grooves. The resin substrate for printed wiring board can be bite in three dimensions in the depth direction of the groove of the metal plate material for printed wiring board, and thus, the resin substrate for printed wiring board. It is possible to more reliably maintain the high durability and reliability of the bonding between the metal plate material for printed wiring boards.

  In particular, by setting the area where the fine particles adhere to the groove to be 3% or more to 60% or less of the area of the groove, it is possible to print more reliably without being hindered by the presence of the fine particles near the groove. The printed wiring board resin base material can be bite in three dimensions in the depth direction of the groove of the wiring board metal plate material, and thereby the printed wiring board resin base material and the printed wiring board metal plate material It becomes possible to more reliably maintain high durability and reliability of bonding.

  In addition, the ratio of the area occupied by adhesion of fine particles to the entire surface of the metal sheet for printed wiring boards is set to 60% to 95% of the total area of the metal sheet for printed wiring boards. The printed wiring board resin base material can be bite in three dimensions in the depth direction of the groove of the printed wiring board metal plate material without being obstructed, and the printed wiring board metal plate material The bonding force of the printed wiring board resin base material on the entire surface of the printed wiring board can be enhanced, thereby further enhancing the durability and reliability of the bonding between the printed wiring board resin base material and the printed wiring board metal plate material. It becomes possible to maintain it reliably.

  Moreover, after performing the 1st surface roughening process and the 2nd surface roughening process to the metal plate material for printed wiring boards, it is any one of Ni plating, Zn plating, chromate processing, and silane coupling processing. Or it becomes possible to maintain reliably further high durability and reliability about joining of the resin base material for printed wiring boards, and the metal plate material for printed wiring boards by performing the process which combined two or more. .

Hereinafter, the metal plate material for printed wiring boards and the manufacturing method thereof according to the present embodiment will be described with reference to the drawings.
FIG. 1 is a diagram showing a laminated structure of a metal plate material for a printed wiring board according to an embodiment of the present invention, FIG. 2 is a diagram showing its main manufacturing process, and FIG. 3 is an embodiment of the present invention. As a comparative example in the operation of the metal plate material for a printed wiring board according to the present invention, the surface structure (a) when the groove is not formed on the surface of the metal plate for the printed wiring board and the groove is filled with fine particles It is a figure which shows typically the surface structure (b).

As shown in FIG. 1, the printed wiring board metal plate 1 according to the present embodiment is firmly bonded to the surface of the printed wiring board resin substrate 2 by a thermocompression bonding process such as a hot press method. Yes.
The printed wiring board metal plate 1a (also referred to as a wiring pattern layer) is subjected to the first roughening treatment and the second roughening treatment, and then the printed wiring board resin substrate 2 on the wiring formation side. Bonded to the surface and further patterned by a photoetching method or the like to form a wiring pattern layer.
The printed wiring board metal plate 1b (also referred to as a heat sink layer) is subjected to the first roughening treatment and the second roughening treatment, and then the wiring forming side of the printed wiring board resin substrate 2 is defined as A heat sink layer is formed by bonding to the opposite surface (back surface side).

As a metal material of the metal plate material 1a for a printed wiring board, for example, a relatively large current is stable in a limited space (that is, with a limited wiring width) required as a wiring pattern layer of an automotive printed wiring board. In order to secure a current capacity that can be passed through, a copper-based board material for a printed wiring board having a thickness of 100 μm or more is preferably used.
The metal material for the printed wiring board metal plate 1b is for a printed wiring board having a thickness of 100 μm or more in the same manner as the metal material for the printed wiring board metal plate 1a in order to ensure the heat dissipation characteristics required for the heat sink layer. A copper-based plate material is preferably used.

  As shown schematically in FIG. 2 (b), the first roughening treatment is performed on the surface of the metal plate material 1 for printed wiring board which is bonded to the resin base material 2 for printed wiring board. The groove 3 is formed such that the ten-point average surface roughness Rz of the surface is 1.0 μm or more and 10 μm or less. In other words, a large number of grooves 3 set to such a depth and density that the ten-point average surface roughness Rz on the surface of the printed wiring board metal plate 1 is 1.0 μm or more to 10 μm or less, That is, it is provided on the surface of the printed wiring board metal plate 1.

  Further, the surface of the printed wiring board metal plate 1 bonded to the printed wiring board resin substrate 2 is schematically shown in FIG. 2C as a second roughening treatment. In addition, fine particles 4 having a particle size of 0.2 μm to 4.0 μm are attached. The fine particles 4 may be one or more of Cu (copper), Ni (nickel), Zn (zinc), Co (cobalt), Fe (iron), Mo (molybdenum), and W (tungsten). It consists of a material that combines metal elements. The particle size of the fine particles 4 is set to a value of 5% to 50% with respect to the Rz value on the surface of the metal plate material 1 for printed wiring board. The distribution density of the fine particles 4 is adjusted to be not less than 60% and not more than 95% of the total area of the metal plate material 1 for a printed wiring board, and in particular, the adhesion area of the fine particles 4 in the groove 3 is It is adjusted to be 3% to 60% of the area in the groove 3. Here, the area in the groove 3 refers to the total surface area including the side surface 3 a and the bottom surface 3 b of the groove 3.

The printed wiring board resin substrate 2 is a flame-retardant resin material made of a composite material of glass fiber and epoxy resin such as FR4 (Frame Regentant Type 4). The printed wiring board metal plate 1 obtained by subjecting the surface of the printed wiring board resin substrate 2 to the first roughening treatment and the second roughening treatment is hot-pressed by a hot press method or the like. Both are firmly joined.

In particular, the first roughening treatment step and the second roughening treatment step in the manufacturing process of the printed wiring board metal sheet 1 are performed according to the flow shown in FIG.
First, an untreated copper-based plate 1c as shown in FIG. 2 (a) is prepared. Grooves 3 are formed on the surface of the copper-based plate 1c as shown in FIG. The groove 3 has a depth and density (Rz (ten-point average surface roughness) of the surface of the printed wiring board metal plate 1 formed by forming the groove 3 so as to be 1.0 μm or more and 10 μm or less. The number or area ratio per unit area on the surface of the metal plate material 1 for printed wiring boards is set, and is formed by a shot blast method, an electro rough plating method, an etching method, a mechanical rubbing method, or the like.

In the first roughening treatment, the groove 3 is formed so that the surface roughness Rz of the printed wiring board metal plate 1 is 1.0 μm to 10 μm as described above. Secure a strong bonding force between the printed wiring board metal plate 1 and the printed wiring board resin substrate 2 by three-dimensionally biting the resin of the printed wiring board resin substrate 2 in the direction. It is an object. In comparison with this purpose, when Rz is less than 1.0 μm, the depth of the groove 3 is shallow, so that a sufficient bonding force cannot be ensured. For this reason, Rz is desirably 1.0 μm or more.
Conversely, when Rz exceeds 10 μm, the groove 3 tends to be too deep. For this reason, it becomes difficult for the resin of the resin substrate 2 for printed wiring boards to enter completely in the depth direction of the groove 3, and so-called voids (voids in which the resin cannot be completely filled) are formed near the bottom of the groove 3. ) Occurs. As a result, the air or water vapor left in the voids expands during heating and damages the wiring board or gradually oozes out toward the surface and corrodes the copper in the wiring pattern layer. Become. For this reason, Rz is desirably 10 μm or less.

  As shown in FIG. 2 (c), the surface of the metal plate material for printed wiring board 1 subjected to the first roughening treatment as described above has a particle size of 0 as the second roughening treatment. The fine particles 4 of 2 μm or more and 4.0 μm or less have an in-plane distribution density of 60% or more and 95% or less with respect to the total area of the metal plate material 1 for a printed wiring board, and The fine particles 4 are adhered by, for example, an electroplating method so that the adhesion area is 3% to 60% of the area in the groove 3. The fine particles 4 are attached to the surface of the printed wiring board metal plate 1 that has been subjected to the first roughening treatment, because the fine particles 4 adhere to the surface of the printed wiring board metal plate 1. The object is to further increase the bonding area with the resin substrate 2 for printed wiring boards by minute irregularities. By increasing the bonding area in this way, it is possible to realize extremely strong bonding between the printed wiring board metal plate 1 and the printed wiring board resin substrate 2 in combination with the above-described enhancement of the bonding force by the grooves 3. Is possible.

  As the fine particles 4 adhered to the surface of the printed wiring board metal plate material 1 by such an electroplating method, any one or more metal elements of Cu, Ni, Zn, Co, Fe, Mo, and W are used. Those made of combined materials are desirable. However, it goes without saying that the present invention is not limited to these.

Here, as schematically shown in FIG. 3A, if the groove 3 is not formed on the surface of the printed wiring board metal plate 1 (the first roughening treatment has not been performed). In this case, the fine particles 4 adhere almost uniformly on the smooth surface of the metal plate 1 for printed wiring board. However, since the groove 3 is not formed, the three-dimensional structure in the depth direction is provided. Since there is no encroachment of the resin, the bonding force is extremely small as compared with the printed wiring board metal plate 1 according to the present embodiment.
On the other hand, when the groove 3 is formed like the metal plate material 1 for a printed wiring board according to the present embodiment, the bonding force is dramatically increased by the groove 3 as described above. On the other hand, as shown schematically in FIG. 3B, the adhesion of the fine particles 4 tends to concentrate on the ridges (edges) of the grooves 3. This is because when the fine particles 4 are attached to the surface of the metal plate material 1 for a printed wiring board, the electric field is concentrated on the edge portion of the groove 3 by the so-called edge effect, and the fine particles 4 are concentrated on that portion. Because. If the fine particles 4 concentrate and adhere to the ridges of the grooves 3 in this way, the ridges, that is, the entrance portions of the grooves 3 are blocked by the fine particles 4, and the resin substrate 2 for printed wiring board 2 It may be difficult for the resin to bite in the depth direction of the groove 3.

From such a viewpoint, the particle size of the fine particles 4 is desirably 4.0 μm or less at the maximum. However, if the particle diameter is too small, the adhesion force of the fine particles 4 itself to the surface of the printed wiring board metal plate 1 is insufficient and the particles 4 are likely to fall off. For this reason, the particle diameter of the fine particles is desirably at least 0.2 μm.
Further, from the same viewpoint as described above, the particle diameter of the fine particles 4 is desirably set to a value of 5% to 50% with respect to the Rz value of the surface of the metal plate material 1 for printed wiring board. That is, when the particle size of the fine particles 4 is more than 50% of Rz (that is, approximately the average value of the depth of the groove 3), there is a high possibility that the fine particles 4 block the inside of the groove 3, and the particle size is Rz. This is because if it is less than 5%, there is a high possibility that the fine particles 4 will drop off from the surface of the printed wiring board metal plate 1.
From the same viewpoint as described above, it is desirable that the adhesion area of the fine particles 4 in the groove 3 is 3% to 60% of the area in the groove 3.
Moreover, it is desirable that the in-plane distribution density of the fine particles 4 on the entire surface of the printed wiring board metal plate 1 is the total area of the printed wiring board metal plate 1. When the in-plane distribution density of the fine particles 4 on the entire surface of the printed wiring board metal plate 1 is less than 60%, the effect of increasing the bonding area with the printed wiring board resin substrate 2 is sufficiently obtained. This is because there is a high possibility that it will disappear, and if it exceeds 95%, there is a high possibility that the fine particles 4 will block the groove 3 as described above.

  According to such a metal plate material for a printed wiring board and a manufacturing method thereof according to the present embodiment, the printed wiring board metal plate material 1 having a maximum thickness of 100 μm or more is bonded to the resin substrate 2 for the printed wiring board. The groove 3 is formed on the surface to be the first roughening treatment so that the ten-point average surface roughness Rz of the surface of the printed wiring board metal sheet 1 is 1.0 μm or more and 10 μm or less, In addition, since the fine particles 4 having a particle size of 0.2 μm to 4.0 μm are attached as the second roughening treatment, the printed wiring board resin substrate 2 is formed in the groove of the printed wiring board metal plate material 1. 3 in the depth direction, and the resin of the printed wiring board resin base material 2 bites into the unevenness of the surface of the printed wiring board metal plate 1 due to the adhesion of the fine particles 4 to increase the bonding area. Print The metal board material 1 for wiring boards and the resin base material 2 for printed wiring boards are joined extremely strongly. As a result, it is possible to maintain high durability and reliability for joining the printed wiring board metal plate 1 and the printed wiring board resin substrate 2.

  In addition, the fine particles 4 are made of a material in which any one or two or more metal elements of Cu, Ni, Zn, Co, Fe, Mo, and W are combined. The fine particles 4 that can adhere to the surface of the plate material 1 can be attached by a simple electroplating process, and thereby high durability for joining the metal plate material 1 for a printed wiring board and the resin base material 2 for the printed wiring board. Reliability and reliability can be reliably maintained.

In addition, by setting the particle size of the fine particles 4 to be not less than 5% and not more than 50% with respect to the value of Rz on the surface of the metal plate material 1 for a printed wiring board, the presence of the fine particles 4 in the vicinity of the grooves 3 The resin of the printed wiring board resin base material 2 can be bite in three-dimensionally in the depth direction of the groove of the printed wiring board metal plate 1 without being obstructed. It becomes possible to reliably maintain high durability and reliability for joining the metal plate material 1 for a plate and the resin base material 2 for a printed wiring board.

  Further, by setting the area of the groove 3 to which the fine particles 4 adhere to be not less than 3% to not more than 60% of the area of the groove 3, it is further ensured without being hindered by the presence of the fine particles 4 in the groove 3. The resin of the printed wiring board resin base material 2 can be bite in three dimensions in the depth direction of the groove 3 of the printed wiring board metal plate material 1, whereby the printed wiring board metal plate material 1 and the printed wiring It is possible to reliably maintain high durability and reliability for bonding with the resin base material 2 for plates.

  Further, by setting the in-plane distribution density of the fine particles 4 on the entire surface of the printed wiring board metal plate 1 to 60% to 95% of the total area of the printed wiring board metal plate 1, a printed wiring board resin is obtained. The joint area with the base material 2 can be effectively increased, and the depth of the groove 3 of the metal plate 1 for printed wiring board is more surely prevented without being hindered by the presence of the fine particles 4 in the groove 3. The resin of the printed wiring board resin base material 2 can be three-dimensionally bited in the direction, and thereby high durability for joining the printed wiring board metal plate material 1 and the printed wiring board resin base material 2 Reliability and reliability can be reliably maintained.

The printed wiring board metal plate material 1 as described in the above embodiment is manufactured, and bonded to the front and back of the printed wiring board resin base material 2 by a hot press method. Was made. Further, as a comparative example, a printed wiring board metal plate material having a setting different from the setting described in the above embodiment was manufactured, and a printed wiring board of each comparative example was manufactured using the metal sheet material. And the peeling strength of the printed wiring board of each of these Examples and each comparative example and the bonding strength retention after 24 hours of PCT (Pressure Cooker Test) were confirmed.
FIG. 4 is a diagram schematically illustrating a method for measuring the peel strength of the printed wiring board of each example and each comparative example, and FIG. 5 relates to the metal plate material for the printed wiring board of each example and each comparative example. It is a figure which shows collectively the peeling strength of each setting printed wiring board produced using it, and the joint strength retention after PCT. Here, in FIG. 5 and the following description, the unit of peel strength is represented by [N / mm], and the unit of bond strength retention is the ratio of the bond strength after PCT to the bond strength before PCT. It was expressed as [%].

  As a copper-type board | plate material 1c which is a copper plate base material of the metal board | plate material 1 for printed wiring boards, the oxygen-free copper plate of 20 cm x 10 cm x 0.28 mm was used. The surface was degreased and then immersed in 12 wt% sulfuric acid for 30 seconds to remove the oxide film on the surface.

Then, as the first roughening treatment, the grooves 3 are formed on the surface of the copper-based plate 1c by a wet etching method using a hydrogen peroxide-based etchant, and the surface roughness Rz of the entire surface is 0.8 μm or more. It was made to become a numerical value falling within a range of ˜12 μm or less.
More specifically, for each example, Examples 1, 2, and 4 have Rz = 4.5 μm, Example 3 has Rz = 6.5 μm, and Comparative Examples 1, 3, and 4 have Rz = 4.5 μm. The grooves 3 were formed so that Comparative Example 5 had Rz = 0.8 μm and Comparative Example 6 had Rz = 12 μm. In Comparative Example 2, the groove 3 was not formed (that is, the first roughening treatment was not performed).

Subsequently, as a second roughening treatment, electric roughening was performed at a current density of 20 A / dm ^{2 to} 50 A / dm ² while keeping the liquid temperature at 40 ° C. using an aqueous solution of 140 g / L copper sulfate to which additives were added. Plating was performed to attach fine particles 4 having a particle size of 0.2 μm to 4.0 μm to the surface of the copper-based plate 1c.
More specifically, for each example, the average particle size of the fine particles 4 was 1.2 μm in Examples 1 and 3, and 2.3 μm in Examples 2 and 4. In addition, the current density and the processing time of the electrolytic copper plating are 9 seconds (indicated as electrolytic copper plating B in FIG. 5) at 30 A / dm ² in Examples 1 and 3, and 50 A / dm ² in Examples 2 and 4. 9 seconds (indicated as electrolytic copper plating C in FIG. 5). According to the setting of these electrolytic copper plating process conditions, the fine particles 4 adhered in each example have an in-plane distribution density of 60% to 95% with respect to the total area of the metal plate material 1 for a printed wiring board. In addition, the adhesion density of the particles 4 inside the groove 3 was 3% or more and 60% or less over the entire area in the groove 3.

Particularly in Example 4, Ni—Co alloy plating and silane cups were further formed on the surface of the printed wiring board metal plate 1 subjected to the first and second roughening treatments with the same specifications as in Example 2. Ring treatment was applied. Ni—Co alloy plating was performed for 10 seconds at a current density of 1.5 A / dm ² using 150 g / L NiSO ₄ and 40 g / L CoSO ₄ as plating solutions. Then, the silane coupling agent process by the general infiltration method was performed.

On the other hand, for each comparative example, the average particle size of the fine particles 4 was 1.2 μm in Comparative Examples 2, 5, and 6, 0.1 μm in Comparative Example 3, and 4.1 μm in Comparative Example 4. In addition, the current density and the processing time of the electrolytic copper plating were set to 9 seconds (indicated as electrolytic copper plating B in FIG. 5) at 30 A / dm ² in Comparative Examples 2, 5, and 6, and 20 A / dm ² in Comparative Example 3. It was 4 seconds (indicated as electrolytic copper plating A in FIG. 5), and in comparative example 4, it was 15 seconds at 50 A / dm ² (indicated as electrolytic copper plating D in FIG. 5). In Comparative Example 1, the fine particles 4 were not attached (that is, the second roughening treatment was not performed). According to the setting of the process conditions for these electrolytic copper plating, in the case of Comparative Examples 2, 5, and 6, the adhesion state of the fine particles 4 is the same as that described in the above embodiment as in each Example. The numerical range was satisfied. In the case of Comparative Example 3, the current density and the processing time are insufficient, and the distribution density of the fine particles 4 is insufficient. In the case of Comparative Example 4, the current density and the processing time are excessive, and the distribution density of the fine particles 4 is insufficient. Became excessive. In the case of Comparative Example 1, as described above, the fine particles 4 are not attached at all.

  Here, the particle size of the fine particles 4 was measured by SEM (scanning electron microscope) observation. Specifically, 20 fine particles 4 in the vicinity of the groove 3 are selected, the area is detected, the diameter of a perfect circle having an equivalent area is calculated, and the average value of the diameters of the 20 circles is calculated. The average particle size was taken.

  The metal plate material 1 for printed wiring board of each Example and each comparative example manufactured in this way was used as a resin substrate 2 for printed wiring board using GEA67-N (product name) manufactured by Hitachi Chemical Co., Ltd. The surface was joined by the hot press method, and the printed wiring board of each Example and each comparative example was produced. Then, an experiment (measurement) was performed to confirm the peel strength of the printed wiring boards of each of the examples and the comparative examples and the bonding strength retention after leaving the PCT for 24 hours.

The peel strength was measured by the T-peel method (see IPC-TM-650) as schematically shown in FIG. That is, after the printed wiring board metal plate 1 is bonded to both the front and back surfaces of the printed wiring board resin substrate 2 by the hot press method, the printed wiring board metal plate 1 on the front and back is peeled up and down respectively. The force applied to the peeling was measured. The peel strength measured in this way was defined as the bonding strength in a normal state. Then, the same peeling strength measurement is performed on each printed wiring board after being left for 24 hours as PCT, and the ratio of the bonding strength measured thereby to the normal bonding strength is expressed in% as the bonding strength retention rate. did. PCT was performed for 24 hours at a temperature of 121 ° C., a humidity of 97%, and a pressure of 196 kPa.
As target values (acceptance standard values), the peel strength was 5.0 N / mm or more and the bonding strength retention was 70% or more.

The result was as shown in FIG.
That is, it was confirmed that each of the metal sheet materials 1 for printed wiring boards of each Example satisfies both the target peel strength of 5.0 N / mm or more and the bonding strength retention of 70% or more.
On the other hand, in the case of the comparative example, it is confirmed that none of them can satisfy one or both of the target peel strength of 5.0 N / mm or more and the bonding strength retention of 70% or more. It was.

More specifically, the surface roughness Rz due to the grooves 3 was formed in the same specifications as in the example, but in the case of Comparative Example 1 in which the fine particles 4 were not attached at all, the peel strength and the bonding strength retention rate. Neither of them met the target value.
In the case of Comparative Example 2 in which the fine particles 4 are adhered but the grooves 3 are not formed at all, neither the peeling strength nor the bonding strength retention rate is satisfied.
The surface roughness Rz due to the groove 3 was formed to the same specifications as in the example, but in the case of Comparative Example 3 in which the particle size of the fine particles 4 was too small than the specification of the example, the peel strength achieved the target value. Although it was possible, the result was that the bonding strength retention rate was not satisfied.
The surface roughness Rz due to the grooves 3 was formed to the same specifications as in the example, but in the case of Comparative Example 4 where the particle size of the fine particles 4 is too larger than the specification of the example, the peel strength achieved the target value. Although it was possible, the result was that the bonding strength retention rate was not satisfied.
The particle size, distribution density, and the like of the fine particles 4 are the same as in the specification of the example, but in the case of Comparative Example 5 in which the surface roughness Rz due to the groove 3 is too small than the specification of the example, the peel strength is the target. Although the value could be achieved, the result was that the bonding strength retention rate was not satisfied.
The particle size, distribution density, and the like of the fine particles 4 are the same as the specifications of the example, but in the case of Comparative Example 6 where the surface roughness Rz due to the grooves 3 is too larger than the specifications of the example, the peel strength is the target. Although the value could be achieved, the result was that the bonding strength retention rate was not satisfied.

From such experimental results, the metal plate material for printed wiring board of each example, in which the grooves 3 are formed with the specifications as described in the above embodiment to adjust the surface roughness Rz and the fine particles 4 are adhered. 1, it was confirmed that both the target peel strength of 5.0 N / mm or more and the bonding strength retention of 70% or more can be achieved.
Moreover, it was confirmed that the metal plate material for printed wiring board of each comparative example could not satisfy one or both of the target peeling strength of 5.0 N / mm or more and the bonding strength retention of 70% or more. .
Furthermore, even when a printed wiring board was manufactured under the same condition setting as in the above example using a plate material with a plate thickness of 100 μm, a plate material with a plate thickness of 1000 μm, and a plate material with a plate thickness of 3000 μm, The target value was achieved.

  Moreover, when the surface of the metal plate material 1 for printed wiring boards of each Example is observed by SEM, in either case, as schematically shown in FIG. 2 (c), the resin of the resin substrate 2 for printed wiring boards The groove 3 having an appropriate depth that can be completely entrapped without causing voids or the like is formed, and the fine particles 4 adhere to the groove 3 at an appropriate density without blocking the ridge (entrance) of the groove 3. It was confirmed that

From the results of these experiments, observations and discussions, the following conclusions were obtained.
If the surface roughness Rz is too small, it is difficult to sufficiently obtain the resin bite (so-called anchor effect) of the resin substrate 2 for the printed wiring board with respect to the metal plate material 1 for the printed wiring board. If it is too large, there is no problem in the peeling strength itself, but the bonding strength retention after PCT is significantly reduced.
If the particle diameter of the fine particles 4 is too small or the distribution density thereof is too small, sufficient bonding strength retention cannot be achieved. In particular, when the distribution density of the fine particles 4 in the vicinity of the ridge portion of the groove 3 or in the groove 3 is too large, or the particle diameter of the fine particles 4 is too large, as schematically shown in FIG. The fine particles 4 block the grooves 3, and the biting of the resin of the printed wiring board resin base material 2 into the printed wiring board metal plate material 1 is hindered, so that the bonding strength retention after PCT is significantly reduced.
Holding the peel strength and bonding strength by further applying Ni / Co plating and silane coupling treatment to the printed wiring board metal plate 1 that has been subjected to the first roughening treatment and the second roughening treatment. Both rates can be even better.

As described above, according to the metal plate material 1 for a printed wiring board according to the present embodiment, printing on the resin base material 2 for the printed wiring board can be performed even under an extremely severe environment such as temperature and humidity as in the PCT experiment. It was confirmed that it was possible to maintain high durability and reliability with respect to the bonding of the metal plate material 1 for wiring boards.
In the above-described embodiments and examples, the case of using the most commonly used copper plate material as the metal plate material of the printed wiring board metal plate material 1 itself has been described, but it is of course not limited thereto. is there. In addition, for example, an aluminum plate or the like can be used. Or if it is a metal plate material with the surface wettability with respect to resin equivalent to a copper plate, it is applicable also to the board | plate material which consists of other materials.
In addition to the Ni / Co plating and silane coupling treatment performed in Example 2, for example, only Ni plating, only Zn plating, only silane coupling treatment, only chromate treatment, or a combination of two or more thereof Etc. are also possible.

It is a figure which shows the laminated structure of the metal plate material for printed wiring boards which concerns on one embodiment of this invention. It is a figure which shows the main manufacturing processes of the metal plate material for printed wiring boards shown in FIG. As a comparative example in the operation of the metal plate material for a printed wiring board according to one embodiment of the present invention, the surface structure (a) and the groove in the case where the groove is not formed on the surface of the metal plate for the printed wiring board are flat. It is a figure which shows typically the surface structure (b) at the time of being filled with microparticles | fine-particles. It is a figure which shows typically about the measuring method of the peeling strength of the printed wiring board of each Example and each comparative example. It is a figure which shows collectively the various settings regarding the metal plate material for printed wiring boards of each Example and each comparative example, and the joint strength of each printed wiring board produced using it, and the joint strength retention after PCT.

Explanation of symbols

1 Metal Plate Material for Printed Wiring Board 2 Resin Base Material for Printed Wiring Board 3 Groove 4 Fine Particle

Claims (7)

A metal plate material for a printed wiring board that has a thickness of 100 μm or more at the thickest portion and is adhered to a plate-shaped resin substrate for a printed wiring board , and fine particles are adhered to a groove provided in a rolled copper foil. And
The groove has a ten-point average surface roughness Rz of 4.5 μm or more to 6.5 μm or less on the surface of the rolled copper foil bonded to the resin substrate for a printed wiring board. It is form formed as, and,
The fine particles have a particle size of 1.2 μm or more and 4.0 μm or less , and the ratio of the area where the fine particles adhere to the inside of the groove to the groove area is 3% or more and 60% or less,
A metal sheet material for a printed wiring board , having a peel strength by a T-peel method of 5.3 N / mm to 6.2 N / mm . In the metal plate material for printed wiring boards according to claim 1,
The print is characterized in that the fine particles are made of a material made of any one metal element of Cu, Ni, Zn, Co, Fe, Mo, and W or a material made by combining two or more metal elements. Metal plate material for wiring boards. In the metal plate material for printed wiring boards according to claim 1 or 2,
The fine metal particle has a particle size of 5% to 50% with respect to the Rz value. In the metal plate material for printed wiring boards according to any one of claims 1 to 3 ,
A metal plate material for a printed wiring board, wherein a ratio of the occupied area of the fine particles to the entire surface of the metal plate material for the printed wiring board is 60% to 95% of the total area of the metal plate material for the printed wiring board . A metal plate material for a printed wiring board in which the thickest part has a thickness of 100 μm or more and is adhered to a plate-like resin substrate for a printed wiring board , and fine particles are adhered to a groove provided in a rolled copper foil. A manufacturing method of
The ten-point average surface roughness Rz of the surface is 4.5 μm or more to the surface of the rolled copper foil bonded to the resin substrate for the printed wiring board in the printed wiring board metal plate . A first roughening step of forming grooves so as to be 5 μm or less;
The ratio of the area where fine particles having a particle size of 0.2 μm to 4.0 μm adhere to the inside of the groove to the surface of the first roughened surface with respect to the groove area is 3%. A method for producing a metal sheet material for a printed wiring board, comprising: a second roughening step for adhering to 60% or less . In the manufacturing method of the metal plate material for printed wiring boards of Claim 5 ,
The method for producing a metal plate material for a printed wiring board, wherein the second roughening step is performed by any one or a combination of two or more of etching, shot blasting, and electric roughening plating. In the manufacturing method of the metal plate material for printed wiring boards of Claim 5 or 6 ,
After performing the first roughening treatment and the second roughening treatment, any one or more of Ni plating, Zn plating, chromate treatment, and silane coupling treatment is further combined. The manufacturing method of the metal plate material for printed wiring boards characterized by performing a process.

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