JP2000114720A - Manufacture of layered printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a contraction factor and the variation of the contraction factor in a heat press process. SOLUTION: A manufacturing method includes a heat press process in which metal foils 4 and 5 are overlaid on the surface and rear 1A and 1B of a copper plate 1 or a layered printed interconnection board with prepregs 2 and 3 therebetween respectively and the layered body is held between a pair of interposed bodies KT1 and KT2 to be heated and compressed. The cusion units KT1 and KT2 have surfaces KT1B and KT2B which are pressed against the metal foils 4 and 5 and have surface roughnesses Rz of not less than 0.4 μm and less than 5 μm respectively. Although the copper foils 4 and 5, etc., tend to contract following the curing contraction of the prepregs 2 and 3, etc., as contraction is obstructed by the friction between the contact surfaces KT1B and KT2A of the interposed bodies KT1 and KT2 and the copper foils 4 and 5, etc., the contraction of the layered printed interconnection board is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated printed wiring board in which an insulating layer and a wiring layer are laminated, and more particularly, to a method for manufacturing a laminated printed wiring board formed by sandwiching an interposed member and hot pressing. .

[0002]

2. Description of the Related Art Conventionally, in order to reduce the size and speed of electronic devices, it has been required to reduce the thickness, increase the number of layers, and reduce the pitch of conductor patterns, etc. for laminated printed wiring boards. Thinning of layers, a method of laminating the layers, a method of forming a conductor pattern, and the like are being studied. First, FIG.
A conventional method for manufacturing a laminated printed wiring board will be described with reference to FIGS. As shown in FIG.
The copper foils 104 and 105 are overlapped on the front surface 101A and the back surface 101B of the first through the prepregs 102 and 103, respectively. The prepreg 10 is vacuum-pressed with the upper die PU and the lower die PD.
2103 resin is cured to form a resin insulation layer 11
2,113. Then, as shown in FIG.
The layers 04 and 105 are etched to form wiring layers 114 and 115 having a predetermined pattern.

Further, in the same manner as above, a resin insulating layer and a wiring layer are laminated. That is, as shown in FIG. 10, this laminated printed wiring board 110 is used as a laminated printed wiring board, and copper foils 108 and 109 are superimposed on front and back surfaces 110A and 110B via prepregs 106 and 107, respectively. Further, the upper and lower molds PU and PD are sandwiched between the two inserts KS1 and KS2, and are subjected to vacuum heating press to harden the resin of the prepregs 106 and 107 to form resin insulating layers 126 and 127, respectively. Then, as shown in FIG. 11, the copper foils 108 and 109 are etched or the like to form wiring layers 128 and 129 of a predetermined pattern. Further, blind holes 121 and 122 are formed in the resin insulating layers 126 and 127 by laser processing or the like in order to connect the wiring layers 128 and 114 or the wiring layers 129 and 115 with each other. Forming the wiring layer 114,
A predetermined circuit is formed by processing such as connection with the receiving lands 114U and 115U formed on the 115, and the laminated printed wiring board 120 is manufactured.

[0004] When further lamination is desired, the above steps are repeated to produce a laminated printed wiring board in which a desired number of resin insulating layers and wiring layers are laminated. Also,
Although not shown, of the laminated printed wiring board 120,
When it is desired to connect the wiring layers 114, 128 on the front surface 101A side of the copper plate 101 and the wiring layers 115, 129 on the rear surface 101B side, the copper plate 101 or the resin insulating layers 112, 113, 1
A through hole penetrating through holes 26 and 127 is formed, and a through-hole conductor is formed on the inner periphery of the through-hole by copper plating or the like for connection.

[0005]

However, in this way, the laminated printed wiring boards 110, 1 are heated by a press.
20 are manufactured, the laminated printed wiring boards 110, 120
It has been found that the size in the direction along the surface (front surface or back surface) becomes smaller, that is, the laminated printed wiring boards 110 and 120 are formed to contract in the direction along the surface. Although the cause is not clear, it is related to the curing shrinkage behavior during curing of the prepreg 102 and the like and the subsequent shrinkage during cooling.
It is considered that when 6 and the like are cured, they are largely cured and shrunk, and are also pulled by the prepreg (resin insulating layer) to shrink the copper foil 108 and the like and the laminated printed wiring board 110 (or the copper plate 101).

[0006] In particular, when the amount of shrinkage of the laminated printed wiring board 120 is large, for example, the planar dimension of the wiring board 120 measured from a reference point (not shown) greatly deviates.
Moreover, immediately after pressing (before forming the wiring layers 128 and 129).
Since the copper foils 108 and 109 cover the surface, the positions of the wiring layers 114 and 115 cannot be determined. Therefore, FIG.
As shown in FIG. 2, even when the blind via 121 is formed at a predetermined position of the formed laminated printed wiring board 120, the receiving land 114U formed on the surface 110A of the laminated printed wiring board 110 is shifted from the predetermined position. As a result (d in the figure), the blind via 121 may come off the receiving land 114U, and a connection failure may occur. In particular, such inconvenience tends to occur remarkably on a high-precision printed wiring board in which fine wirings and vias are formed. This is because a slight displacement easily causes a connection failure.

On the other hand, when the shrinkage ratio (shrinkage amount) is known in advance, it can be dealt with by manufacturing by correcting the dimensions in consideration of the shrinkage ratio. However, since the shrinkage in the heating press process has a large shrinkage ratio (shrinkage amount) and a large variation, the shrinkage ratio (shrinkage amount) is predicted and taken into consideration in advance, and the laminated printed wiring such as the positioning of the blind via is determined. It is difficult to design the board 120, and the higher the precision of the printed wiring board, the lower the yield is.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce a shrinkage rate (shrinkage amount) in a heating press step in a method of manufacturing a laminated printed wiring board having a heating press step. In addition, it is possible to reduce the variation in the shrinkage rate (shrinkage amount). Furthermore, it is possible to form a wiring layer with high dimensional accuracy, and to provide a method for manufacturing a multilayer printed wiring board with high manufacturing yield and high reliability. To provide.

[0009]

Means for Solving the Problems, Actions and Effects The means for solving the problem is that a metal foil is laminated via a prepreg on the front and back surfaces of a metal plate or a laminated printed wiring board, respectively, and the surface roughness is Rz = 0. This is a method for manufacturing a laminated printed wiring board, comprising a heating press step of hot-pressing while sandwiching the metal foil between two contact surfaces of 4 μm or more and Rz = less than 5 μm.

According to the present invention, a metal foil is placed on the front and back surfaces of a metal plate or a printed wiring board to be laminated via a prepreg, and the metal foils are brought into contact with the two contacting surfaces. And a step of hot-pressing the sheet. Moreover, the surface roughness of the contact surface is Rz = 0.
The range is 4 μm or more and less than 5 μm. In this case, the shrinkage ratio of the laminated printed wiring board after the hot pressing can be reduced, and the variation in the shrinkage ratio can be suppressed. This is because, in the heating press step, when the prepreg cures and shrinks, the metal foil is pulled in the direction of shrinking, whereas the contact surface in contact with the metal foil prevents shrinkage of the metal foil due to friction. It is considered that it suppresses shrinkage of the metal foil, prepreg (resin insulating layer), and laminated printed wiring board (or metal plate). Moreover,
It is considered that because the surface roughness was set, a frictional force was stably generated between the metal foil and the contact surface, and the metal foil was fixed.

Therefore, the wiring layer can be formed with high dimensional accuracy. For example, even if a blind via is formed at a predetermined position on a molded laminated printed wiring board, the blind via is located at a position off the receiving land as in the conventional case. It is formed, and no electrical failure occurs, and the connection can be made reliably. Alternatively, even when a through hole is formed in a molded laminated printed wiring board and a through-hole conductor is formed, a through via is formed at a position deviated from a through hole formed at a predetermined position on a metal plate (or a laminated printed wiring board to be laminated). It is possible to reliably connect the wiring layers without being formed. Therefore, it is possible to eliminate a defect such as a connection failure due to shrinkage and to improve yield and reliability. In addition, it is possible to design in consideration of the shrinkage (amount), and it is possible to manufacture a high-precision laminated printed wiring board having finer wiring and the like.

Here, the surface roughness of the two contact surfaces needs to be Rz = 0.4 μm or more and Rz = less than 5 μm, respectively. This is because if Rz is less than 0.4 μm, the shrinkage rate increases, and the variation in shrinkage also increases.
This is because sufficient frictional resistance cannot be obtained between the contact surface and the metal foil, so that when the metal foil is pulled by the shrinkage of the prepreg, slippage occurs between the contact surface and the metal foil, It is considered that because the foil shrinks in accordance with the shrinkage of the prepreg, the prepreg, the metal plate, and the printed wiring board to be laminated shrink greatly, and the shrinkage rate of the entire laminated printed wiring board increases. Further, it is considered that the amount of slip is not constant but has a variation, so that the variation in the shrinkage ratio also increases.
On the other hand, when Rz exceeds 5 μm, the irregularities existing on the contact surface become too large, and the irregularities are transferred to the metal foil, and the metal foil is partially broken.

In order to keep the surface roughness in the above range, the contact surface may be finished by using a known processing technique. May be adjusted as appropriate to adjust the surface roughness. Here, the contact surface refers to a surface that comes into contact with and presses the metal foil, and may be, for example, a press surface of a press die (upper die and lower die). In the case where an interposer is interposed between the press die and the metal foil, it refers to the surface of the interposer that comes into contact with the metal foil.

The metal plate may be selected in consideration of conductivity, workability, and the like, and examples thereof include a copper plate and a copper alloy plate. In addition, a laminate having a suitable thickness may be used in consideration of the rigidity and the like of the laminated printed wiring board to be manufactured. The printed wiring board to be laminated may be any printed wiring board capable of laminating a resin insulating layer and a wiring layer on the front and back surfaces, for example, a wiring board formed on both sides of a board made of a composite material such as glass epoxy or And a laminated printed wiring board in which a plurality of wiring layers and insulating layers are alternately laminated. The printed wiring board to be laminated may be one manufactured by the manufacturing method of the present invention or another manufacturing method.

The prepreg may be appropriately selected in consideration of the insulating property, moisture resistance, heat resistance and the like of the cured resin insulating layer. For example, thermosetting resins such as epoxy resins and polyimide resins, composite materials of these resins with glass fibers (glass woven fabric, glass non-woven fabric), and composite materials of organic fibers such as polyester and aramid fibers (aramid cloth, etc.) , Composite materials in which a thermosetting resin such as an epoxy resin is impregnated into a fluororesin base material having a three-dimensional network structure such as continuous porous PTFE, and a composite material such as a thermosetting resin and an inorganic powder such as a ceramic powder. No. Further, the metal foil may be selected in consideration of conductivity, easiness of etching, and the like, and examples thereof include a copper foil. The thickness may be appropriately selected according to the design of the laminated printed wiring board, for example, by selecting an appropriate thickness for forming a wiring layer.

Here, in the above-mentioned method for manufacturing a laminated printed wiring board, an intervening body is interposed between the metal foil and the press die, and the abutting surfaces are respectively provided with the two interposed bodies. It is preferable to use a method of manufacturing a laminated printed wiring board, characterized in that the surface is a surface to be brought into contact with the metal foil.

According to the present invention, the metal foil is laminated on the front and back surfaces of the metal plate or the laminated printed wiring board via the prepreg, and the metal foil is brought into contact with each of the two inserts. A step of performing hot pressing with a press die (upper die and lower die) between them. In addition, the surface roughness of the surface of the interposed body that comes into contact with the metal foil is in the range of Rz = 0.4 μm or more and less than 5 μm. This interposed body is prepared separately from the press die, and the surface roughness of the contact surface is finished using the above-mentioned known processing technique. In general, press dies are designed according to the structure of the press machine, so they tend to have large and complex shapes.To finish or maintain or maintain the press surface to a predetermined surface roughness It takes a lot of trouble and cost. On the other hand, in the case where an insert is interposed between the press die and the metal foil instead of processing the press surface of the press die, the contact surface of the insert is easy. Therefore, the burden such as labor and cost can be reduced.

Further, since this interposer is designed separately from the press die, there is an advantage that the shape and the material can be freely designed according to the laminated printed wiring board to be manufactured. In other words, when a material having a coefficient of thermal expansion similar to that of the metal foil is selected, the behavior during heating and cooling can be made closer to the metal foil, and the slip between the metal foil and the metal foil can be further suppressed. It is preferable because shrinkage of the plate and its variation can be suppressed. For example, as described below, when a copper foil is used as the metal foil, copper of the same material or stainless steel (SUS304, SUS30
2 etc.). The dimensions such as the thickness of the interposer may be appropriately designed in consideration of the heat capacity and heat transfer at the time of hot pressing and the size and thickness of the laminated printed wiring board to be manufactured. The insert is a press mold (upper and lower dies)
Alternatively, the pressure may be applied repeatedly by pressing each time, or may be integrated with the press die.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying a method for manufacturing a laminated printed wiring board according to the present invention will be described below with reference to the drawings. First, as shown in FIG. 1, a continuous porous P is formed on a front surface 1A and a back surface 1B of a copper plate 1 having a substantially plate shape having a thickness of 35 μm and having a plurality of through holes 1H formed at predetermined positions.
Copper foils 4 and 5 each having a thickness of 12 μm are stacked via prepregs 2 and 3 made of a composite material in which TFE is impregnated with an epoxy resin, and the contact surfaces KT1B and KT2A are each finished to a predetermined surface roughness. It is sandwiched between the inserts KT1 and KT2. Further, this is sandwiched between the upper die PU and the lower die PD, the upper die PU is lowered, and the upper die PU and the lower die PD are vacuum-heat-pressed to harden the resin of the prepregs 2 and 3 so that the resin insulating layers are respectively formed. 12, and 13. In this heating press step, the resin of the prepregs 2 and 3 is cured by heating in a vacuum state while pressing, and the copper plate 1 and the resin insulating layers 12 and 3 are cured.
13, and the resin insulating layers 12, 13 and the copper foils 4, 5 are joined. Then, it cools, pressing.

Here, the copper plate 1, the prepregs 2, 3 and the copper foils 4, 5 have a substantially plate shape of 330 × 330 mm. The inserts KT1 and KT2 are made of stainless steel SUS304 having the same expansion coefficient as the copper foils 4 and 5, and the contact surfaces KT1B and KT2A have a surface roughness of Rz = 2.0 μm.
? It is finished to become. In addition, SUS3
04 has almost the same coefficient of thermal expansion as copper foils 4 and 5,
The behavior of inserts KT1 and KT2 during heating and cooling was
5 and the slip between the copper foils 4 and 5 can be suppressed, so that the contraction and the variation of the laminated printed wiring board can be suppressed. This insert KT1,
The finishing of the contact surfaces KT1B and KT2A of KT2 will be described later.

The press-formed laminated printed wiring board has a structure in which resin insulating layers 12 and 13 are bonded to the front and back surfaces 1A and 1B of the copper plate 1, and copper foils 4 and 5 are further bonded to the front and back surfaces. Next, as shown in FIG. 2, the copper foils 4 and 5 are subjected to etching or the like to form wiring layers 14 and 15 having a predetermined pattern. Further, the wiring layer 14 on the front surface 10A and the back surface 10B
In order to connect the wiring layer 15 with the wiring layer 15, a through hole connecting the front and back surfaces 10A and 10B is formed at a position where the through hole 1H previously formed at a predetermined position of the copper plate 1 is located, and an inner periphery thereof is formed. A through-hole conductor 16 is formed by copper plating, and a via or the like is formed by filling a gap between the holes with an epoxy 17 or the like.

Further, a resin insulating layer and a wiring layer are laminated in the same manner as described above. That is, as shown in FIG. 3, the laminated printed wiring board 10 is used as a laminated printed wiring board, and copper foils 8 and 9 are superimposed on the front and back surfaces 10A and 10B via prepregs 6 and 7, respectively. Surface KT1B,
Two inserts KT1, each of which has a surface roughened KT2A.
Insert between KT2. Lower the upper PU to lower the upper P
U and the lower die PD are vacuum-heat-pressed to cure the resin of the prepregs 6 and 7 so that the resin insulating layers 26 and 2 are respectively formed.
7 is assumed.

Then, as shown in FIG. 4, the copper foils 8 and 9 are subjected to etching or the like so that the wiring layers 28 and 2 having a predetermined pattern are formed.
9 is formed. Also, blind holes 23 and 24 are formed in the resin insulating layers 26 and 27 by laser processing or the like, and the wiring layers 28 are formed.
In order to connect the wiring layers 14 and the wiring layer 29 and the wiring layer 15, blind vias 21 and 22 are formed, and the receiving lands 14U and 15 formed in the wiring layers 14 and 15 are formed.
Processing such as connection with U is performed. Although not shown, the wiring layer 28 on the front surface 20A and the wiring layer 29 on the rear surface 20B are not shown.
In order to connect the front and back surfaces 20A, 20A, the through holes 1H, which have been formed at predetermined positions of the copper plate 1 in advance, are located.
The laminated printed wiring board 20 is manufactured by forming a through-hole connecting the wires 20B and forming a through-hole conductor by copper plating on the inner periphery thereof. By repeating the above-described steps, a desired number of wiring layers and resin insulating layers are laminated, and a laminated printed wiring board 30 as shown in FIG. 5 is manufactured. This laminated printed wiring board 30 had good connection between each wiring layer and the via, and did not cause disconnection (disconnection).

Next, FIG. 6 and Table 1 show the relationship between the surface roughness of the surfaces KT1B and KT2A of the interposed bodies KT1 and KT2 which are in contact with the copper foils 4, 5, 8, and 9, and the shrinkage of the laminated printed wiring board. This will be described with reference to FIG. Copper foil 4,5,8,9
The following investigation was conducted on the surface roughness of the contact surfaces KT1B and KT2A. First, the contact surfaces KT1B and KT2A of the inserts KT1 and KT2 are buff-polished using abrasive grains having different numbers, and the surface roughness is adjusted in eight steps in the range of Rz = 0.1 to 5.0 μm. did. This contact surface KT1
The surface roughness of B, KT2A was measured by a contact type surface roughness measuring instrument.

Then, as shown in FIG.
At a predetermined position, a through hole 1 penetrating the front and back surfaces 1A, 1B
MA, 1 MB was formed at a distance L (about 250 mm). Next, as shown in FIG.
Lay the prepregs 2 and 3 on the copper plate 1 and further thickness 12 μm
The laminated printed wiring board 10C which laminated | stacked the copper foils 4 and 5 of this was manufactured. Here, processing for forming the wiring layer is not performed. Next, as shown in FIG. 6C, the copper foil 4 near the position where the through holes 1MA and 1MB previously formed in the copper plate 1 are located.
And the resin insulating layer 12 are removed, and the through holes 1MA and 1MB are removed.
The distance M between them was measured. Then, based on the measurement results of the distance L and the distance M, the shrinkage ratio S of the laminated printed wiring board 10C is determined.
Was calculated according to the following equation. In addition, 5 panels were prepared for the same surface roughness, and 4 panels were prepared for each panel.
The location was measured to obtain a total of 20 data. Shrinkage ratio S = (LM) / L * 100 (%) Further, for each surface roughness, the average value Sm of the shrinkage ratio and the maximum value S of the shrinkage ratio are calculated from the results of the 20 calculations by the above formula.
max, shrinkage minimum value Smin, shrinkage variation Sr
(The value obtained by subtracting the minimum value Smin from the maximum value Smax). In addition, since some of the copper foils 4 and 5 were torn, the tear rate T of the copper foils 4 and 5 after the hot pressing step was determined. These results are summarized in Table 1, and the relationship between the surface roughness Rz and the average value Sm of the shrinkage is shown in FIG.

[0026]

[Table 1]

As is clear from the results in Table 1 and FIG.
As the surface roughness Rz increases, the average value Sm of the shrinkage rate rapidly decreases, and the average value Sm at Rz = 0.4 or more.
Is substantially constant, and it is understood that the average value Sm is particularly small and constant when Rz = 0.6 or more. On the other hand, the variation Sr of the shrinkage also decreases rapidly as the surface roughness Rz increases, and the variation Sr is almost constant at Rz = 0.4 or more, and the variation Sr particularly decreases at Rz = 2.0 or more. I understand. Furthermore, regarding the state of the copper foil,
When Rz = 4.0, the copper foil is not broken, but Rz = 5.
At 0, it can be seen that the copper foil is torn. From this, it can be seen that when the surface roughness Rz is in the range of 0.4 ≦ Rz <5.0, the average value Sm and the variation Sr are almost constant and small, and the copper foil is not broken. Preferably, the range is 0.6 ≦ Rz <5.0. This is because the average value Sm is particularly small, the variation Sr is almost constant and the copper foil is not broken. More preferably, the range is 2.0 ≦ Rz <5.0. This is because the average value Sm and the variation Sr are particularly small, and the copper foil is not broken. Further, 2.0 ≦ Rz ≦ 4.0
In the range, the average value Sm and the variation Sr are particularly small, and the copper foil is not broken. Although data is not shown, substantially the same result was obtained even when the same shrinkage rate was measured for a case where a plurality of layers were further laminated from the state of FIG. 6B.

The reason that the shrinkage of the laminated printed wiring board is suppressed as described above is that when the prepregs 2 and 3 cure and shrink in the heating press step, the copper foils 4 and 5 in contact with the prepregs 2 and 3 are pulled in a direction to shrink. On the other hand, the inserts KT1 and KT2 abutting on the copper foils 4 and 5 prevent the copper foils 4 and 5 from contracting due to friction. As a result, it is considered that the shrinkage of the copper foils 4 and 5, the prepregs 2 and 3 (the resin insulating layers 12 and 13), and the copper plate 1 (or the laminated printed wiring boards 10 and 20) is suppressed.

From the above, of the interpolated bodies KT1 and KT2,
When the surface roughness of the surfaces KT1B and KT2A that are in contact with the copper foils 4, 5, 8, and 9, respectively, is within the above ranges, the shrinkage of the laminated printed wiring boards 10, 20, and 30 after hot pressing is reduced, and Variation in shrinkage can also be suppressed. Therefore, for example, the molded laminated printed wiring board 20
Even if the blind vias 21 and 22 are formed at predetermined positions, the blind vias 21 and 22 are formed at positions deviated from the receiving lands 14U and 15U as in the related art, and no electrical failure occurs. Connection can be made securely. Alternatively, the formed laminated printed wiring boards 10, 2
0, the copper plate 1 (or the printed wiring board 10 to be laminated) is formed even when the through-hole conductor 16 is formed.
The wiring layers can be reliably connected without forming the through via 16 at a position deviating from the through hole formed at the predetermined position. Therefore, it is possible to eliminate a defect such as a connection failure due to shrinkage and to improve yield and reliability. In addition, a design that allows for a shrinkage (amount) becomes possible, and a high-precision laminated printed wiring board 30 having finer wiring and the like can be manufactured.

In the above, the present invention has been described with reference to the embodiments. However, it is needless to say that the present invention is not limited to the above embodiments, and can be appropriately modified and applied without departing from the gist thereof. . For example, although the copper plate 1 having a thickness of 35 μm was used as the metal plate, the thickness may be selected in consideration of the rigidity of the metal plate or the multilayer printed wiring board, for example, a thickness of 50 μm, 100 μm, 150 μm, or the like. May be used. Further, as the metal foil, a copper foil having a thickness of 12 μm was used, but it may be selected in consideration of the ease of processing of the wiring layer and the like, and a metal foil thicker or thinner, for example, 9 μm, 15 μm, 20 μm, Thicknesses such as 30 μm can be used.

In the above embodiment, the copper plate 1 has a through hole 1H which has been opened in advance. However, after lamination, a metal foil (copper foil) or a resin insulating layer may be punched at once. You may do it. Further, in the above embodiment, the resin insulating layer is perforated by laser processing, but may be perforated by a drill. Alternatively, the holes may be formed at once by laser processing, including the metal plate (copper plate 1) and the metal foil (copper foils 4, 5 and the like).

In the above-described embodiment, the laminated printed wiring board 30 is manufactured by interposing the inserts KT1 and KT2 between the upper die PU or the lower die PD and the copper foils 4, 5, etc. Without using the inserts KT1 and KT2, the lower surface (press surface) of the upper die PU and the upper surface (press surface) of the lower die PD are each finished to the above-described surface roughness, and these surfaces are directly formed on the copper foil. The heat pressing may be performed so as to be in contact.
Further, the inserts KT1 and KT2 may be bonded to the upper die PU and the lower die PD, respectively, and may be subjected to heat press working integrally. In this case, it is possible to eliminate the trouble of overlaying the inserts KT1 and KT2 on the copper foils 4 and 8 or laying the inserts KT1 and KT2 under the copper foils 5 and 9 every time hot pressing is performed.

[Brief description of the drawings]

FIG. 1 is an explanatory view illustrating a step of laminating a prepreg and a copper foil on both surfaces of a copper plate by hot pressing in a method of manufacturing a laminated printed wiring board according to an embodiment.

FIG. 2 is a partially enlarged cross-sectional view of a (substrate) laminated printed wiring board in which a wiring layer is formed by processing a laminated copper foil in the method of manufacturing a laminated printed wiring board according to the embodiment.

FIG. 3 is an explanatory view illustrating a step of laminating a prepreg and a copper foil on a laminated printed wiring board shown in FIG. 2 by a hot press in the method of manufacturing a laminated printed wiring board according to the embodiment.

4 is a partially enlarged cross-sectional view of a (printed) laminated printed wiring board in which a wiring layer is formed by processing a copper foil laminated in the step shown in FIG. 3 in the method for manufacturing a laminated printed wiring board according to the embodiment; is there.

FIG. 5 is a partially enlarged cross-sectional view of the laminated printed wiring board completed by the method for manufacturing a laminated printed wiring board according to the embodiment.

6A and 6B are explanatory diagrams illustrating a method for measuring a shrinkage ratio of a laminated printed wiring board, wherein FIG. 6A is a method for measuring a distance L between through holes formed in a copper plate before hot pressing, and FIG. (C) shows a method of measuring the distance M corresponding to the distance L between the through holes formed in the copper plate in the laminated printed wiring board.

FIG. 7 is a graph showing the relationship between the surface roughness Rz of the contact surface of the interposer and the average value Sr of the shrinkage of the laminated printed wiring board.

FIG. 8 is an explanatory view illustrating a step of laminating a prepreg and a copper foil on both surfaces of a copper plate by a hot press in a method of manufacturing a laminated printed wiring board in a conventional technique.

FIG. 9 is a partially enlarged cross-sectional view of a (substrate) laminated printed wiring board in which a wiring layer is formed by processing a laminated copper foil in a method of manufacturing a laminated printed wiring board in a conventional technique.

FIG. 10 is an explanatory view illustrating a step of laminating a prepreg and a copper foil on the laminated printed wiring board shown in FIG. 2 by a hot press in a method of manufacturing a laminated printed wiring board in a conventional technique.

FIG. 11 is a partially enlarged cross-sectional view of a (substrate) laminated printed wiring board in which a wiring layer is formed by processing copper foil laminated in the process described in FIG. is there.

FIG. 12 is an explanatory view illustrating a state in which a blind via comes off a receiving land due to shrinkage of a laminated printed wiring board according to a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Copper plate (metal plate) 1A (copper plate) front surface 1B (copper plate) back surface 2,3,6,7 Prepreg 4,5,8,9 Copper foil (metal foil) 10,20 Laminated printed wiring board (laminated print (Wiring board) 10A (laminated printed wiring board 10)
Surface 10B (laminated printed wiring board 10)
Back) 20A (laminated printed wiring board 20)
Surface 20B (laminated printed wiring board 20)
) Back surface 12, 13, 26, 27 Resin insulating layer 14, 15, 28, 29 Wiring layer 30 Laminated printed wiring board KT1, KT2 Interposed body KT1B, KT2A (of interposed body) Contact surface PU Upper die PD Lower Type

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F100 AB01A AB17C AB17E AB33C AB33E AK18 AK53 AT00E BA05 BA06 BA10E DH01B DH01D DJ10 EC01 EJ59 EJ82 GB43 JA03 JL02 JL04 5E346 AA03 AA12 AA24 BB01 CC08 EE09 EE06

Claims (2)

[Claims] 1. A metal foil is laminated on the front and back surfaces of a metal plate or a printed wiring board to be laminated via prepregs, and two contact surfaces having a surface roughness of not less than Rz = 0.4 μm and less than Rz = 5 μm, respectively. A method for manufacturing a laminated printed wiring board, comprising a heating press step of heating and pressing while holding the metal foil in contact with the metal foil. 2. The method for manufacturing a laminated printed wiring board according to claim 1, wherein an interposed body is interposed between the metal foil and a press die, and the contact surfaces are two A method for manufacturing a laminated printed wiring board, which is a surface of the interposer that is in contact with the metal foil.