KR20110097961A - Multilayer printed board and method for manufacturing the same - Google Patents

Abstract

The multilayer printed circuit board 10 includes a resin film 15 having a through hole 11, a conductive pattern 12 formed on one side, and a conductive through hole 14 formed integrally with the conductive pattern 12 on the inner wall of the through hole. ) Are overlapped with each other in the vertical direction. Between two adjacent resin films among the plurality of resin films 15, the conductor patterns 12 and the conductors 23 which are bonded to each other with the conductive pattern 12 and the conductive through holes 14 are provided, respectively. The interlayer connection between the conductor patterns 12 of each resin film is integrated with the conductor pattern 12 and the conductive through hole 14 and the conductor 23 without interposing another resin film between two adjacent resin films. Through).

Description

Multilayer printed circuit board and manufacturing method therefor {MULTILAYER PRINTED BOARD AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a multilayer printed circuit board and a manufacturing method thereof.

Conventionally, as a manufacturing method of a multilayer printed circuit board, there exists a manufacturing method of the multilayer substrate disclosed by following patent document 1, patent document 2, etc., for example.

Patent Document 1 manufactures a plurality of double-sided substrates having interlayer connection, and laminates the plurality of double-sided substrates through a film-like insulator which is subjected to interlayer connection, thereby manufacturing a multilayer substrate having electrodes on both sides of the substrate. Is disclosed.

Patent Document 2 discloses a method of manufacturing a multilayer substrate having electrodes on both sides by laminating a single-sided conductor pattern film having a conductor pattern formed only on one side of the resin film and removing the resin film so that the electrodes are exposed. In addition, Patent Document 2 removes the single-sided conductor pattern film forming the surface of the multilayer substrate, and the bottom-side via hole having the conductor pattern as the bottom is formed in the single-sided conductor pattern film, and the conductive paste is filled in the bottomed via hole. Thereby, the technique which conducts the conductor pattern of adjacent single-sided conductor pattern films via this electrically conductive paste is disclosed. According to this, the conductive pattern layers of the multilayer substrate can be conducted by the conductive paste in the via holes.

Japanese Patent Laid-Open No. 2000-38464 (Japanese Patent No. 3355142) Japanese Patent Laid-Open No. 2003-86948 (Japanese Patent No. 3407737)

By the way, in the prior art disclosed by the said patent document 1, it is a structure in which another resin film is interposed between two adjacent resin films of the some resin film in which the conductor pattern was formed in the single side | surface. Moreover, also in the prior art disclosed by the said patent document 2, it is a structure in which another resin film is interposed between two adjacent resin films of the some resin film in which the conductor pattern was formed in both surfaces. For this reason, a large number of parts increases manufacturing cost.

Moreover, at the time of a fusion | melting press, another resin film tends to deform | transform between two adjacent resin films, and it is difficult to take all the interlayer connection electrically, and the interlayer connection reliability is low. In particular, when a thermoplastic resin is used for the resin film, the film tends to deform during the fusion press, and the problem that the variation occurs in the thickness as a multilayer substrate was remarkable.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and an object thereof is to provide a multilayer printed circuit board having high interlayer connection reliability and a method of manufacturing the same, while reducing the number of parts and reducing manufacturing costs. have.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the multilayer printed circuit board which concerns on invention of Claim 1 has the resin film which has a through hole, the conductor pattern formed in the single side | surface, and the conductive through hole formed integrally with the said conductor pattern in the inner wall of the said through hole, respectively. A plurality of sheets of the plurality of resin films are overlapped with each other in the vertical direction, and conductors respectively provided between the conductor patterns opposing between two adjacent resin films and the land portion of the conductive through hole are bonded to each other between metals. It is characterized by.

According to this structure, the conductor pattern formed in the single side | surface and the resin film which has a conductive through-hole are the same in the up-down direction, and a plurality of sheets overlap and the conductor is opposed between two adjacent resin films among these resin films. Coupling between the conductor pattern and the conductive through hole and the metal. Thereby, between two adjacent resin films, the opposing conductor pattern and the conductive through hole are electrically connected by the conductor and mechanically coupled. In the multilayered printed circuit board integrated in this manner, the interlayer connection between the conductor patterns of each resin film is connected to the conductor pattern and the conductive through hole and conductor without interposing another resin film between two adjacent resin films. Is done through. Therefore, the number of parts can be reduced, the manufacturing cost can be reduced, and the interlayer connection reliability is high.

In the multilayer printed circuit board according to the invention of claim 2, the conductor pattern and the conductive through hole have a base metal layer and a conductor layer formed on the base metal layer, and the conductor pattern is formed on the conductor layer. do.

According to this structure, by making a conductor pattern and a conductive through hole into the two-layer structure which has a base metal layer and a conductor layer, adhesiveness with the resin film of a conductor layer becomes favorable, and interlayer connection reliability improves further.

In the multilayer printed circuit board according to the invention of claim 3, the base metal layer is formed of a Ni-P alloy having a thickness of 2 to 6% and a thickness of 0.05 micrometer, and the conductor layer is formed of Cu. .

A multilayer printed circuit board according to the invention of claim 4 is characterized in that the conductor is a metal containing Sn.

The multilayer printed circuit board which concerns on invention of Claim 5 is a thermoplastic resin whose glass transition point and melting | fusing point are 150 degreeC or more and 350 degrees C or less, The said resin film is characterized by the above-mentioned.

In the multilayer printed circuit board which concerns on invention of Claim 6, the said resin film is a film in which crystal has optical anisotropy, It is characterized by the above-mentioned.

In the multilayer printed circuit board which concerns on invention of Claim 7, the said resin film contains polyaryl ketone resin and amorphous polyetherimide, It is characterized by the above-mentioned.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of the multilayer printed circuit board which concerns on the invention of Claim 8 consists of a through hole, the conductor pattern formed in the single side | surface, and the conductive through hole formed integrally with the said conductor pattern in the inner wall of the said through hole, respectively. The process of producing the resin film which has, the process of forming the plating layer containing Sn in at least one of the said conductor pattern of the said resin film, and the land part of the said through-hole, and the said some resin films are made the same in the up-down direction While laminating the conductive layer and the conductive through-hole facing each other between the two adjacent resin films so as to sandwich a plating layer containing Sn, respectively, a laminate in which a plurality of the resin films are laminated is opened. It is characterized by including the process of overlapping by a fusion press.

According to this structure, the conductor pattern formed in the single side | surface and the resin film which has a conductive through-hole are made the same in the up-down direction, and several sheets overlap, and it contains Sn between two adjacent resin films among these several resin films. The conductor formed by melting the plated layer by the thermal fusion press bonds the opposing conductor pattern and the land portion of the conductive through hole to the metal. Thereby, between two adjacent resin films, the opposing conductor pattern and the land portion of the conductive through hole are electrically connected by the conductor and mechanically coupled. In the multilayered printed circuit board integrated in this manner, the interlayer connection between the conductor patterns of each resin film is connected to the conductor pattern and the conductive through hole and conductor without interposing another resin film between two adjacent resin films. Is done through. Therefore, the number of parts can be reduced, the manufacturing cost can be reduced, and the interlayer connection reliability is high.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the manufacturing method of the multilayer printed circuit board which concerns on invention of Claim 9 includes the through-hole, the conductor pattern formed in the single side | surface, and the conductive through-hole formed integrally with the said conductor pattern in the inner wall of the said through-hole, respectively. A conductive paste or a metal powder is formed between the step of producing a resin film to have, and the plurality of the resin films having the same up-down direction, and between the conductor pattern and the land portion of the conductive through hole facing each other between two adjacent resin films. And laminated | stacked through each other, and the process of superimposing the laminated body which laminated | stacked the several sheets of said resin film by the heat-sealing press is characterized by the above-mentioned.

According to this structure, the conductor pattern formed in the single side | surface and the resin film which has a conductive through-hole are the same in the up-down direction, and a plurality of sheets overlap, and the electrically conductive paste hardens between two adjacent resin films among these several sheets of resin film. The conductor thus formed is bonded to the opposite conductor pattern, the conductive through hole, and the metal. Thereby, between two adjacent resin films, the opposing conductor pattern and the conductive through hole are electrically connected by the conductor and mechanically coupled. In the multilayered printed circuit board integrated in this manner, the interlayer connection between the conductor patterns of each resin film is connected to the conductor pattern and the conductive through hole and conductor without interposing another resin film between two adjacent resin films. Is done through. Therefore, the number of parts can be reduced, the manufacturing cost can be reduced, and the interlayer connection reliability is high.

The manufacturing method of the multilayer printed circuit board which concerns on invention of Claim 10 forms the base metal layer by electroless-plating on the single side | surface of the said resin film and the inner wall of the said through hole in the process of manufacturing the said resin film, The said base metal layer After forming a conductor layer by electroplating on it, the said conductor pattern is formed in the said conductor layer, It is characterized by the above-mentioned.

According to this structure, adhesiveness of a conductor layer becomes favorable by making the conductor of a conductor pattern, and a conductive through hole into the two-layer structure which has a base metal layer and a conductor layer. Thereby, interlayer connection reliability improves further. In addition, since the base metal layer is formed by electroless plating, the thickness of the conductor between the conductor pattern and the conductive through hole can be reduced. Thereby, a fine conductor pattern can be formed. On the other hand, in the prior art disclosed in the above Patent Documents 1 and 2, since the conductor pattern is formed after the copper foil is fused and pressed to the film, the thickness of the copper foil is limited and is not suitable for fine processing. Further, since the conductor pattern and the conductive through hole are formed at the same time, the conductor thickness of the conductor pattern and the conductive through hole is uniform while the connection reliability is high.

The manufacturing method of the multilayer printed circuit board which concerns on invention of Claim 11 is the said electrically conductive paste containing the metal powder containing at least Sn, Cu, and Ag, It is characterized by the above-mentioned.

According to the present invention, the number of parts can be reduced, the manufacturing cost can be reduced, and a multilayer printed circuit board with high interlayer connection reliability can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows schematic structure of a part of multilayer printed circuit board which concerns on 1st Embodiment.
FIG. 2 is an enlarged partial cross-sectional view of a portion of FIG. 1; FIG.
(A)-(D) is a process chart which shows the manufacturing procedure of a resin film.
4 is an explanatory diagram showing the arrangement order of the respective constituent members before performing the heat fusion press;
5 is a cross-sectional view illustrating a schematic configuration of a part of a multilayer printed circuit board according to the second embodiment.
6 (A) to (D) are process charts showing the production procedure of the resin film.
7 is an explanatory diagram showing the arrangement order of the respective constituent members before the implementation of the thermal fusion press.

Next, each embodiment which actualized this invention is described based on drawing. In addition, in description of each embodiment, the same code | symbol is attached | subjected to the same site | part, and the overlapping description is abbreviate | omitted.

(1st embodiment)

The multilayer printed circuit board which concerns on 1st Embodiment is demonstrated based on FIG.

1 is a cross-sectional view showing a schematic configuration of a part of a multilayer printed circuit board according to the first embodiment, and FIG. 2 is an enlarged partial cross-sectional view of a part of FIG. 1.

The multilayer printed circuit board 10 shown in FIG. 1 is formed in three multilayer printed circuit boards as an example. The multilayer printed circuit board 10 includes a through hole 11, a conductive pattern 12 formed on one side, and a conductive through hole 14 formed integrally with the conductive pattern 12 on the inner wall of the through hole 11, respectively. The resin film 15A, 15B, 15C which has is made the same in the up-down direction, and is overlapping several sheets.

In this embodiment, three resin films 15A, 15B, and 15C each having the same shape are overlapped as an example. These three resin films 15A, 15B, and 15C are superposed so that the center of the conductive through hole 14 may coincide.

In the multilayered printed circuit board 10, the conductive through holes 14 of the resin films 15A, 15B, and 15C are opposite to the surface on which the conductor pattern 12 is formed from the inner wall of the through hole 11. Each of the lands 14a (see FIG. 3D) is bent and extended on its surface.

In this multilayer printed circuit board 10, the conductor pattern which opposes between two adjacent resin films among resin films 15A, 15B, and 15C, ie, between resin films 15A and 15B and resin films 15B and 15C, is opposed. The conductors 23, which are bonded to each other with the land portion 14a of the 12 and the conductive through hole 14, are provided. The conductor 23 is plated with Sn (plating Sn) on the land portion 14a of the conductive through hole 14 to form a Sn plating layer 23A (see FIG. 3E), Sn in the Sn plating layer 23A is melted at the time of fusion press or after press. Thereby, the conductor pattern 12 and the land part 14a of the conductive through hole 14 which oppose between two adjacent resin films 15A and 15B and the resin films 15B and 15C are respectively connected to a conductor ( 23) are electrically connected and mechanically coupled together.

The multilayer printed circuit board 10 includes a resist film 41 covering the entire conductor pattern 12 of one of the resin films 15A and 15C (resin film 15C) on both sides thereof, and the other ( The resist film 42 which covers the whole land 14a of the conductive through hole 14 of the resin film 15A is provided. The resist film 41 is provided with a through hole 41a for exposing a part of the conductor pattern 12 (a portion serving as an electrode). On the other hand, the through film 42a for exposing the land 14a of the conductive through hole 14 is formed in the resist film 42.

In addition, the conductor pattern 12 and the conductive through hole 14 of each resin film 15A, 15B, and 15C are formed in one conductor 13. As shown in FIG. 2, this conductor 13 has a base metal layer 13a and a conductor layer 13b formed on the base metal layer 13a. The conductor pattern 12 is formed in the conductor layer 13b on one side of each resin film 15A, 15B, 15C.

The resin films 15A, 15B, and 15C and the resist films 41 and 42 are made of the same film base material, for example. Although a film base material may use a common glass cloth base epoxy resin, BT resin, etc., it is more preferable to use a thermoplastic resin for a film base material from a viewpoint of joining two or more sheets by fusion press. Examples of the thermoplastic film include a liquid crystal polymer film, polyetheretherketone (PEEK), polyethersulfone (PES), polyphenyleneether (PPE), and polytetrafluoroethylene (PTFE). Moreover, you may use a thermoplastic polyimide.

The multilayer printed circuit board 10 having the above configuration is integrated by heat fusion press in a state in which the resin films 15A, 15B and 15C and the resist films 41 and 42 are laminated as shown in FIG. 1. By this heat fusion press, Sn of 23 A of Sn plating layers melts, and the conductor 23 which metal-bonded with the land pattern 14a of the conductor pattern 12 and the conductive through-hole 14 is produced | generated. In this way, in the multilayered printed circuit board 10 integrated with each other, between the resin patterns 15A, 15B, and 15C between two adjacent resin films, the other resin film is not interposed, but between the conductor patterns 12 of each resin film. The interlayer connection is made via the conductive pattern 12 and the conductive through hole 14 and the conductor 23 integrally with each other.

Next, the manufacturing method of the multilayer printed circuit board 10 which has the said structure is demonstrated based on FIG. 3 and FIG. It is process drawing which shows the manufacturing procedure of a resin film, and FIG. 4 is explanatory drawing which shows the arrangement order of each structural member before implementation of a heat fusion press.

(1) First, a resin film having a through hole 11, a conductor pattern 12 formed on one side, and a conductive through hole 14 formed integrally with the conductor pattern 12 on the inner wall of the through hole 11, respectively. The process of producing (15A, 15B, 15C) is performed. Since these resin films 15A, 15B, and 15C have the same structure, the process of producing the resin film 15A is demonstrated here.

In this step, first, the through hole 11 is formed in the resin film 15A shown in FIG. 3A by punching (see FIG. 3B).

Subsequently, as shown in FIG. 3C, the base metal layer 13a and the conductor layer 13b formed on the base metal layer 13a on both surfaces of the resin film 15A and the inner wall of the through hole 11. Conductor 13 (see Fig. 2) is formed. The base metal layer 13a is formed by an electroless plating process. In addition, the conductor layer 13b is formed by an electroplating process.

Next, in the conductor 13, the conductor pattern 12 is formed in the conductor layer 13b (see FIG. 2) of the conductor 13 on one side of the resin film 15A by photoetching or the like (Fig. 3). (D)). In addition, the conductor on the surface on the opposite side to the conductor pattern 12 of the resin film 15A is removed by etching or the like leaving the land 14a of the conductive through hole 14.

(2) Next, Sn plating (Sn electroplating) is performed on the conductive through holes 14 and the land portions 14a of the resin films 15B and 15C to form Sn plating layers 23A (FIG. 3E). Reference).

Sn electroplating used Rotexan EC-J made from Meltex as an additive.

Sn electric plating solution

1 st tin sulfate 40 g / L

Sulfuric acid 100mL / L

Additive Ronastan EC-J

Temperature 20 ℃

Current density 2 A / dm ²

In addition, it is not limited only to Sn, It may be Sn-Cu alloy plating (plating bath: Topfried BR etc. made by Okuno Seyaku Kogyo Co., Ltd.). Sn-Ag alloy plating may be sufficient.

The Sn plating method is not limited to electroplating, and may be substituted plating. In that case, after etching the both-side conductor pattern, it immersed in the following plating liquid (any of three types is possible), and the copper surface was substituted and Sn was formed into 2 micrometers.

Substitution plating:

Tin 1 Chloride 18.8 g / L

Sodium Cyanide 188g / L

Sodium Hydroxide 22.5g / L

Room temperature

Sodium Tartrate 60g / L

Sodium Cyanide 120g / L

Sodium Hydroxide 7.5g / L

Temperature 21-65 ℃

1 st tin chloride 6 g / L

Thiourea 55g / L

Tartaric Acid 39g / L

Temperature 12-14 ℃

(3) Next, as shown in FIG. 4, the resin films 15A, 15B, and 15C were laminated in the vertical direction, and the resist film 41 was formed on the resin film 15C. The resist film 42 is laminated | stacked under 15A), respectively, and the process of superimposing a laminated | stacked laminated body by a heat welding press is performed.

By the thermal fusion press, the conductive paste 23A provided between each of the conductor patterns 12 and the both ends 25a of the conductive through holes 25 is cured, and the conductor patterns 12 and the conductive through holes 14 are cured. A conductor 23 is formed between the end portion 14a of the ()) and the metal, and the multilayer printed circuit board 10 shown in FIG. 1 is completed. Thereby, the multilayered printed circuit board 10 shown in FIG. 1 is completed. By heat fusion press, the Sn plating layer 23A formed between each conductor pattern 12 and the land part 14a of the conductive through hole 14 melts, and the land part of the conductor pattern 12 and the conductive through hole is melted. A conductor (metal including Sn) 23 bonded to the metal 14a and 14a is obtained.

In addition, after performing a thermal fusion press at a temperature lower than the Sn melting point, heat may be applied to the Sn melting point or higher to melt the Sn to form a conductor bonded to the metal.

In addition, although the process mentioned above showed the example in which each through-hole 14 of the resin films 15A, 15B, and 15C becomes coaxial, it is not necessary for each conductive through-hole 14 to be coaxial. none. Between two adjacent resin films, the land portion 25a of the conductive pattern 12 and the conductive through hole 25 of the resin film 22 may be intermetallic bonded by the conductor 23 at an arbitrary place. .

According to 1st Embodiment comprised as mentioned above, the following effects are exhibited.

○ Two adjacent resin films of the resin patterns 15A, 15B, and 15C (multiple resin films) having the conductive pattern 12 formed on one side and the conductive through hole 14 are the same in the vertical direction. Between the resin films, the conductors 23 are bonded to the land portions 14a of the conductor patterns 12 and the conductive through holes 14 that face each other. The conductor 23 melts Sn in the Sn plating layer 23A during or after thermal fusion pressing. Thereby, between the two adjacent resin films, the opposing conductor pattern 12 and the conductive through-hole 14 are electrically connected by the conductor 23, and are mechanically coupled. In the multilayered printed circuit board 10 integrated in this manner, the interlayer connection between the conductor patterns of each resin film is integrated with the conductor pattern 12 without interposing another resin film between two adjacent resin films. It is made through the through hole 14 and the conductor 23. Therefore, the number of parts can be reduced, the manufacturing cost can be reduced, and a multilayer printed circuit board with high interlayer connection reliability can be obtained.

○ The resin film of the conductor layer 13b by making the one conductor 13 in which the conductor pattern 12 and the conductive through hole 14 are formed into a two-layer structure which has the base metal layer 13a and the conductor layer 13b. Since adhesiveness with is improved, interlayer connection reliability improves further.

Since the underlying metal layer 13a is formed by electroless plating, the conductor thickness of the conductor pattern 12 and the conductive through hole 14 can be made thin. Thereby, the fine conductor pattern 12 can be formed.

Since the conductor pattern 12 and the conductive through hole 14 are formed at the same time, the conductor thickness of the conductor pattern 12 and the conductive through hole 14 is uniform while the connection reliability is high.

(2nd embodiment)

The multilayered printed circuit board 10A according to the second embodiment will be described with reference to FIGS. 5 to 7.

Next, the multilayer printed circuit board 10A which concerns on 2nd Embodiment of this invention is demonstrated based on FIG.

In the multilayer printed circuit board 10 of the first embodiment, the conductor 23 bonded to the conductor pattern 12 and the conductive through hole 14 and the metal is obtained by melting Sn of the Sn plating layer 23A.

On the other hand, in the multilayer printed circuit board 10A according to the second embodiment, the conductor 33 (see FIG. 5) that is coupled between the conductor pattern 12 and the conductive through hole 14 and the metal is a conductive paste ( 33A) (FIG. 6E, FIG. 7) is hardened | cured. Thereby, the conductor pattern 12 and the conductive through-hole 14 which oppose between two adjacent resin films, ie, between resin films 15A and 15B and between resin films 15B and 15C, have conductors 33. It is electrically connected and mechanically coupled via. That is, in this multilayer printed circuit board 10A, the conductive through hole 14 formed in the inner wall of the conductive through hole 11 in the resin films 15 (15A, 15B, 15C), the conductor 33, and the resin The conductive through hole 25 in the film 22 is used for interlayer connection. The other structure of the multilayer printed circuit board 10A is the same as that of the multilayer printed circuit board 10 of 1st Embodiment.

Next, the manufacturing method of the multilayer printed circuit board 10A which has the said structure is demonstrated based on FIG. 6 and FIG. It is process drawing which shows the manufacturing procedure of a resin film, and FIG. 7 is explanatory drawing which shows the arrangement order of each structural member before implementation of a heat fusion press.

In this case, after performing the process of said (1) (refer FIG.6 (A)-(D)), the process of said (2), (3) is carried out following process (2A), (3A) Substituted by

(3A) The conductive paste 33A is interposed between the conductor pattern 12 and both land portions 25a of the second conductive through holes 25 (see FIG. 7E). In this example, the conductive paste 33A is applied onto both land portions 25a of the second conductive through holes 25.

(4A) Next, the process of laminating | stacking the 1st resin film 15 and the 2nd resin film 22 alternately is performed.

In this process, the resist film 42, the 1st resin film 15, the 2nd resin film 22, and the resist film 41 are laminated | stacked in the order shown in FIG. 8, and these laminated bodies are superimposed by heat fusion press. do. Thereby, the multilayered printed circuit board 10A shown in FIG. 1 is completed. By heat-sealing press, the electrically conductive paste 33A provided between each conductor pattern 12 and both land parts 25a of the 2nd conductive through-holes 25 hardens | cures, and the conductor pattern 12 and the 2nd It becomes the conductor 33 which couple | bonded with both land parts 25a of the conductive through-hole 25 and metal.

According to the multilayered printed circuit board 10A produced in this manner, the conductor patterns 12 and the conductive through holes 14 which face each other between the two adjacent first resin films 15 and 15 form the conductor 33. Since they are electrically connected and mechanically coupled through the same, the same effects as those of the first embodiment can be obtained.

(Example 1)

<Method for Manufacturing Multilayer Printed Board 10 or 10A>

Sn plating was performed on the land portion 14a and the inner wall of the conductive through hole 14. Sn plating formed the Sn plating layer 23A of 1 micrometer thickness.

Subsequently, the resist film 42, the some resin film, and the resist film 41 were laminated | stacked in the order shown in FIG. 7, and the collective thermal fusion press was performed.

It carried out in the range of the press temperature of 150-350 degreeC, and the press pressure of 0.5-10 Mpa. In Example 1 shown in Table 1 below, Sn plated on the land portion 14a was melted by a press of 1 MPa at 280 ° C., and an electrical connection was made by coupling the conductive through hole with the metal between the conductor pattern.

In Example 2, a 50-micrometer-thick liquid crystalline polymer film (BIAC (registered trademark) BC manufactured by Japan Gore-Tex Corporation) was used as the film substrate.

In Example 3, PEEK / PEI (IBUKI (registered trademark) manufactured by Mitsubishi Jushi Co., Ltd.) having a thickness of 50 µm was used as the film substrate. The press pressure and the press temperature were thermally fused under the conditions shown in Table 1.

Examples 4-6 produced the multilayer board | substrate on the resin film shown in Table 1, and press conditions. Ag paste was used for the connection of the conductive through-hole of a 2nd film, and the conductor pattern of a 1st resin film. The conductive paste 33A is applied by screen printing, the conductive paste 33A is cured by thermal fusion press, and the conductor 33 (see FIG. 6) on which each conductive paste 33A is cured is subjected to a conductor pattern and The second conductive through hole was bonded to the metal. As the electrically conductive paste 33A, Fujitaku Kasei Doctite XA-824 was used. Press conditions are shown in Table 1.

Examples 7-9 produced the multilayer board | substrate on the resin film shown in Table 1, and press conditions. AgSn paste was used for connection of the conductive through-hole of a 2nd film, and the conductor pattern of a 1st resin film. As for the detail of the paste, the thing of Paragraph 0075 of Unexamined-Japanese-Patent No.3473601 was used. In the same manner as in Examples 4 to 6, a multilayer substrate was produced.

The through hole 11 was formed by the carbon dioxide gas laser.

The through-hole 11 may use not only a carbon dioxide gas laser but a UV-YAG laser in a small diameter, and may use an excimer laser. In addition, you may process the through hole 11 with a mechanical drill.

Film roughening and desmear:

The punched-out 1st resin film 15 was immersed in strong alkali, the surface was melt | dissolved, and it roughened.

Irregularities were formed on the surface by immersion in 10 ssd potassium hydroxide solution at 80 ° C. for 15 to 30 minutes. At the same time, the resin smear generated during the formation of the through hole 11 was dissolved and removed, and the surface of the inner wall of the through hole 11 was also roughened.

By electroless plating, Ni-P was plated on the surface of the resin film 15 as base plating (base metal layer 13a).

A conditioner treatment, an electroless plating treatment of a nickel phosphorus alloy, a heat treatment, and an electroplating treatment of copper were carried out in order to prepare a film metal-clad laminate.

Electroless Plating:

The conditioner treatment wash | cleaned the surface of a polymer film by the OPC-350 conditioner by the Seiku Kogyo Co., Ltd .. Here, the OPC-500 catalyst made by Okuno Seyaku Kogyo Co., Ltd. and the OPC-500 accelerator were used as the catalyst imparting liquid containing palladium.

In the electroless plating treatment of the nickel alloy, nickel (Ni) -phosphorus (P) plating was performed on both surfaces of the first resin film 15. The phosphorus concentration was 5% or less, and was selected from commercially available nickel-phosphorus plating solutions. Ni plating thickness was formed to 0.2 micrometer thickness using the chemical nickel EXC of Okuno Seyaku Kogyo Co., Ltd.

The plating liquid is not limited to this, and may be used N-plate Ni-426 of Meldex, Top Nicolon LPH-LF of Okuno Seyaku Kogyo Co., Ltd., and the like.

You may heat-process in order to improve adhesiveness before copper plating. The heating for 30 second-30 minutes was performed at the temperature of 230-250 degreeC. In this example, heating was performed at 240 ° C. for 3 minutes.

Copper electroplating:

Further, copper electroplating was performed to form the conductor layer 13b of the conductor 13 to a thickness of 1 to 10 micrometers. The electroplating process of copper (Cu) formed copper so that the conductor thickness of the conductor layer 13b might be 5 micrometers. The copper electroplating solution used the following. As an additive, Cubelite TH-RIII manufactured by Ebara Yuji Light Co., Ltd. was used.

Copper Sulfate 120g / L

Sulfuric acid 150g / L

Concentrated hydrochloric acid 0.125mL / L (as chlorine ion)

Fabrication of conductor pattern 12:

The conductor pattern 12 formed the circuit on both surfaces (the conductor layer 13b of the conductor 13) of the 1st resin film 15 by the subtractive method. The photosensitive resist was apply | coated, and it exposed by ultraviolet-ray, and developed. Subsequently, after performing an etching process to form a conductor pattern, the resist was peeled off. Further, finer circuit formation may be performed by using a semi-additive method in which the electroplating thickness (conductor thickness) is set to 2 to 3 micrometers in thickness and the electroplating is applied to the conductor pattern portion after the plating resist is formed. none.

<Method for Manufacturing Multilayer Printed Board 10A>

33 A of electrically conductive pastes were apply | coated by screen printing on both land parts 25a of each 2nd electroconductive through-hole 25. As shown in FIG.

Next, the resist film 42, the 1st resin film 15, the 2nd resin film 22, and the resist film 41 were laminated | stacked in the order shown in FIG. 5, and the package thermal fusion press was performed.

It carried out in the range of the press temperature of 150-350 degreeC, and the press pressure of 0.5-10 Mpa. By this press, each conductive paste 33A is hardened, and the conductor 33 which each conductive paste 33A hardened is couple | bonded with a conductor pattern, a 2nd conductive through-hole, and metal.

The conductor 33 and the conductor pattern 12 of the resin film 15 were electrically connected. As the electrically conductive paste 33A, Fujitaku Kasei Doctite XA-824 was used. As the conductive paste 33A, AgSn paste was used. As for the detail of the paste, the thing of Paragraph 0075 of Unexamined-Japanese-Patent No.3473601 was used.

In Example 2, a 50-micrometer-thick liquid crystal polymer film (Vecstar (registered trademark) CT-50N manufactured by Kuraray Co., Ltd.) was used as the film substrate.

In Example 3, PEEK / PEI (IBUKI (registered trademark) manufactured by Mitsubishi Jushi Co., Ltd.) having a thickness of 50 µm was used as the film substrate.

In Examples 4, 5, 7 and 8, the same film substrate as in Example 2 was used.

In Examples 6 and 9, the same film substrate as in Example 3 was used.

In addition, in Examples 2-9, the multilayer board | substrate was produced like Example 1, and press pressure and temperature were performed on the conditions of Table 1.

(Comparative Example)

As a comparative example 1-6, the single-sided laminated board and the double-sided laminated board which used the copper foil and the film were used, and the multilayer paste was produced by heat-sealing the thing which filled the electrically conductive paste in the blind via hole formed in the film for interlayer connection. The conditions are shown in Table 2 below.

The preparation method of the multilayer board | substrate of Comparative Examples 1-6 is shown below.

The conductor pattern was formed by the etching using the copper clad laminated board which heat-fused copper foil and the film. Via holes were formed by laser.

The electrically conductive paste was apply | coated to the via hole of the film by the screen printing method.

The fusion | melting of the film which embedded the electrically conductive paste was piled up in plural sheets, and the collective thermal fusion press was performed. It carried out in the range of the press temperature of 230-350 degreeC, and the press pressure of 0.5-10 Mpa. In this press, the films were fused together, and the conductive paste filled in the via holes of the film was cured to electrically connect the conductive paste and the conductor pattern of the film. As the electrically conductive paste, Doctite XA-824 from Fujikura Kasei was used as the Ag paste. As the conductive paste, AgSn paste was used. As for the detail of the paste, the thing of Paragraph 0075 of Unexamined-Japanese-Patent No.3473601 was used.

Comparison of Connection Reliability:

The six-layer board | substrate of the conductor pattern conforming to L of the negative part 2.1 of JIS C 5012 was produced. However, the hole diameter of the interlayer connection part was 100 micrometers, the land diameter was 0.5 mm, the wiring width was 0.3 mm, and the gap between the through holes was 7.62 mm. In the comparative example, via holes having a diameter of 100 micrometers were produced at the same through hole positions as the present invention to fill the conductive paste. In this invention, the temperature cycle test corresponding to 9.1.3 description condition 1 of JIS C 5012 was implemented, and it investigated about the interlayer connection reliability. Connection failure was considered when the resistance value increased by 20% or more with respect to the initial resistance.

According to each of the above examples, the following effects were obtained.

Press thickness deformation amount after fusion press is small.

Through-hole connection reliability is high.

In addition, this invention can also be actualized in the following changes.

In each said embodiment, the number of laminated | multilayer of a resin film is not limited to "3", This invention is applicable widely to the multilayer printed circuit board which laminated | stacked the several sheets of resin film.

In the second embodiment, a metal powder may be used instead of the conductive paste 33A.

10, 10A: multilayer printed circuit board
11: through hole
12: conductor pattern
13: conductor
13a: base metal layer
13b: conductor layer
14: Challenge Through Hole
15, 15A, 15B, 15C: Resin Film
23, 33: conductor
23A: Plating layer containing Sn
33A: conductive paste

Claims (11)

A plurality of resin films each having a through hole, a conductor pattern formed on one side, and a conductive through hole formed integrally with the conductor pattern on the inner wall of the through hole are overlapped in the up-down direction,
A multilayer printed circuit board, wherein a conductor provided respectively between the conductor patterns facing each other between two adjacent resin films among the plurality of resin films and the land portion of the conductive through hole are bonded between metals. The multilayer printed circuit board according to claim 1, wherein the conductor pattern and the conductive through hole have a base metal layer and a conductor layer formed on the base metal layer, and the conductor pattern is formed in the conductor layer. 3. The multilayer printed circuit board of claim 2, wherein the base metal layer is formed of a Ni-P alloy having a thickness of 2 to 6% and a thickness of 0.05 micrometers, and the conductor layer is formed of Cu. The multilayer printed circuit board according to any one of claims 1 to 3, wherein the conductor is a metal containing Sn. The multilayer printed circuit board according to any one of claims 1 to 4, wherein the resin film is a thermoplastic resin having a glass transition point and a melting point of 150 ° C or more and 350 ° C or less. The multilayer printed circuit board according to any one of claims 1 to 4, wherein the resin film is a film in which crystals have optical anisotropy. The multilayer printed circuit board according to any one of claims 1 to 4, wherein the resin film comprises a polyaryl ketone resin and an amorphous polyetherimide. A step of producing a resin film each having a through hole, a conductor pattern formed on one side, and a conductive through hole formed integrally with the conductor pattern on an inner wall of the through hole;
Forming a plating layer containing Sn in at least one of the conductor pattern of the resin film and the land portion of the conductive through hole;
The plurality of resin films are laminated so that a plating layer containing Sn is interposed between the conductor pattern and the conductive through hole facing each other between the two adjacent resin films with the same vertical direction. Process of superimposing the laminated body which laminated | stacked the several sheets of the said resin film by the heat-sealing press
A method for producing a multilayer printed circuit board comprising: A step of producing a resin film each having a through hole, a conductor pattern formed on one side, and a conductive through hole formed integrally with the conductor pattern on an inner wall of the through hole;
While laminating the plurality of resin films with the conductive paste or the metal powder interposed between the conductor pattern and the land portion of the conductive through hole facing each other between two adjacent resin films with the same vertical direction, Process of superimposing the laminated body which laminated | stacked the several sheets of the said resin film by the heat-sealing press
A method for producing a multilayer printed circuit board comprising: The process for producing the resin film according to claim 8 or 9, wherein a base metal layer is formed on one side of the resin film and an inner wall of the through hole by electroless plating, and the electroplating is performed on the base metal layer. By forming a conductor layer, then forming the conductor pattern on the conductor layer. The method of manufacturing a multilayer printed circuit board according to claim 9, wherein said conductive paste contains a metal powder containing at least Sn, Cu, and Ag.

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