JP5831342B2 - Multilayer substrate manufacturing method - Google Patents

Description

  The present invention relates to a method for producing a multilayer substrate in which a plurality of resin films are laminated to form a laminated body, and the laminated body is integrated by pressing from above and below both sides in a laminating direction with a press plate. is there.

  Conventionally, there has been proposed a multilayer board in which a plurality of wiring patterns are formed in multiple layers in a resin, and the plurality of wiring patterns are electrically connected via an interlayer connection member.

  Such a multilayer substrate is manufactured as follows, for example. That is, first, a plurality of resin films in which a wiring pattern is formed on one surface and a conductive member is filled in a via hole having the wiring pattern as a bottom surface are prepared. And a some resin film is laminated | stacked and a laminated body is comprised. Then, this laminate is placed between a pair of press plates, and the laminate is pressed while being heated from above and below both sides in the stacking direction, thereby joining the resin films and sintering the conductive paste. An interlayer connection member is formed. Thereby, the multilayer substrate with which the laminated body was integrated is manufactured.

  However, in the above manufacturing method, the press plate is brought into direct contact with the laminate to integrate the laminate, so that the pressure applied to the laminate is in-plane due to unevenness caused by the wiring pattern formed on one surface of the resin film. Will vary. For this reason, there is a problem that the flow amount of the resin in the vicinity of the wiring pattern is different from the flow amount of other parts, and the positional deviation of the wiring pattern and the positional displacement of the interlayer connection member (conductive paste) occurs.

  In order to solve this problem, for example, Patent Document 1 proposes that a cushioning material in which a glass fiber nonwoven fabric is packed with a packing material is disposed between a laminate and a press plate. According to this, when the laminated body is integrated, the glass fiber nonwoven fabric is pulverized or melted, so that the cushioning material has a shape corresponding to the unevenness caused by the wiring pattern, and the laminated body is pressed through this cushioning material. Pressurized from the plate. Therefore, it can suppress that the pressure applied to a laminated body varies in a plane.

JP 2010-147419 A

  In the manufacturing method of the above-mentioned patent document 1, in order to make the shape corresponding to the unevenness caused by the wiring pattern by pulverizing or melting the glass fiber nonwoven fabric, a packaging material necessary only for packing the glass fiber nonwoven fabric is an essential member. It becomes. However, at present, there is a desire to reduce the number of parts by eliminating the packing material.

  An object of this invention is to provide the manufacturing method of the multilayer substrate which can suppress the dispersion | variation in the surface of the pressure applied to a laminated body, without using a packing material in view of the said point.

In order to achieve the above object, according to the first aspect of the present invention, a wiring pattern (11) is formed on one surface (20a) and a via hole (21) having the wiring pattern as a bottom surface is formed. A step of laminating a plurality of resin films including a resin film (20) filled with a conductive paste (22) to form a laminate (30), and the laminate between a pair of press plates (30) And placing the cushioning material (50) between the laminated body and the press plate, and pressurizing and unifying the laminated body while heating with the press plate from the lamination direction via the cushioning material. And using a material composed of an inorganic material-based fiber nonwoven fabric containing an organic binder as a cushioning material . In the placement step, the cushioning material and the laminate are viewed from the stacking direction of the laminate. Planar shape In the step of arranging and integrating a pair of release papers that are larger than the cushioning material, one end of the pair of release papers and the other of the pair of release papers while contacting the pair of release papers on the side of the laminate It is characterized in that it is spaced apart from the end portion .

  According to this, when integrating a laminated body, an inorganic material type fiber nonwoven fabric is tied together by an organic binder, and a buffer material plastically deforms according to the unevenness | corrugation resulting from a wiring pattern. And since a laminated body is heated and pressurized via this buffer material, the packaging material which packs a buffer material is not required, but the in-plane dispersion | variation in the pressure applied to a laminated body can be suppressed.

Moreover , it can suppress that the buffering material arrange | positioned between a laminated body and a press board contacts, and it can suppress that a multilayer substrate is covered with a buffering material.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is sectional drawing of the multilayer substrate in 1st Embodiment of this invention. It is sectional drawing which shows the manufacturing process of the multilayer substrate shown in FIG. It is sectional drawing which shows the manufacturing process of the multilayer substrate in 2nd Embodiment of this invention. It is sectional drawing when a laminated body is integrated using the release paper whose planar shape is smaller than the planar shape which looked at the laminated body from the lamination direction.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
A first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, in the multilayer substrate of this embodiment, a plurality of wiring patterns 11 are formed in a multilayer in a thermoplastic resin 10, and the plurality of wiring patterns 11 are electrically connected via an interlayer connection member 12. It is connected.

  Next, a method for manufacturing such a multilayer substrate will be described with reference to FIG.

  First, as shown in FIG. 2A, a copper foil or the like is formed on one surface 20a of the resin film 20, and the copper foil is patterned to form a wiring pattern 11. A via hole 21 having the wiring pattern 11 as a bottom is formed by a carbon dioxide laser or the like. Thereafter, the conductive paste 22 is filled into the via hole 21 by a screen printer or the like. The conductive paste 22 is, for example, a paste that is kneaded by adding an organic solvent such as paraffin to metal particles such as Ag and Sn.

  Next, as shown in FIG. 2B, a laminate 30 is formed by laminating a plurality of (eight in FIG. 2) resin films 20 subjected to the process of FIG. Specifically, the laminate 30 is configured by laminating a plurality of resin films 20 so that one surface 20a of the resin film 20 on which the wiring pattern 11 is formed is positioned at both ends of the laminate 30 in the lamination direction. Although not particularly limited, in the present embodiment, the first to fourth sheets of the resin film 20 constituting the lower layer are laminated so that one surface 20a is positioned on the lower side, and the fifth to eighth sheets constituting the upper layer. The resin film 20 is laminated so that one surface 20a is positioned on the upper side. That is, the fourth and fifth resin films 20 constituting the laminate 30 are arranged so that the conductive pastes 22 are in contact with each other, and the other resin films 20 are symmetrical with respect to these resin films 20. Are stacked.

  In this embodiment, the plurality of resin films 20 are a plurality of thermoplastic resin films made of polyetheretherketone (PEEI), polyetherketone (PEK), etc. The thermosetting resin film which consists of a thermoplastic resin film of this, and several sheets of polyimide (PI) etc. may be sufficient. In the case where the plurality of resin films 20 are a thermoplastic resin film and a thermosetting resin film, it is preferable that the thermoplastic resin film and the thermosetting resin film are alternately laminated.

  Subsequently, as shown in FIG. 2C, the laminate 30 is disposed between the pair of hot press plates 40, and the buffer material 50 and the release paper 60 are provided between the laminate 30 and the hot press plate 40. Place. Specifically, among the laminate 30 and the hot press plate 40, the release paper 60 is arranged on the laminate 30 side, and the cushioning material 50 is arranged on the hot press plate 40 side.

  The buffer material 50 suppresses in-plane variation of the pressure applied to the laminate 30 in the step of FIG. 2D described later, and is made of an inorganic material fiber nonwoven fabric containing an organic binder. Examples of the organic binder include acrylamide and acrylic resin, and examples of the inorganic material include glass, ceramic, rock wool, and slag wool. Moreover, since the release material 60 contains the organic binder, the release material 60 suppresses the attachment of the release material 50 to the laminated body 30 in the step of FIG. In the step 2 (d), a polyimide (PI) film, a polytetrafluoroethylene (PTFE) film, or the like that is not bonded to the laminate 30 is used.

  In the present embodiment, the laminate 30, the hot press plate 40, the cushioning material 50, and the release paper 60 have a rectangular planar shape and the same size. The planar shape is a shape when the stacked body 30 is viewed from the stacking direction side. Moreover, the hot press board 40 is comprised, for example with electroconductive metals, such as titanium, and the thing of the structure which generate | occur | produces heat | fever when it supplies with electricity is used.

  Then, as shown in FIG. 2 (d), the laminated body 30 is pressed while being heated from the upper and lower surfaces in the laminating direction by the hot press plate 40, and the buffer material 50 is applied to the wiring pattern 11 formed on each resin film 20. While plastically deforming according to the unevenness caused, the resin films 20 are joined and the conductive paste 22 is sintered to form the interlayer connection member 12 and the laminate 30 is integrated.

  At this time, the buffer material 50 is not shattered because the inorganic material fiber nonwoven fabric is held together by the organic binder. Thereafter, although not particularly illustrated, the release paper 60 is peeled from the multilayer substrate, whereby the multilayer substrate shown in FIG. 1 is manufactured.

  As described above, in this embodiment, the buffer material 50 is configured using an inorganic material-based fiber nonwoven fabric containing an organic binder. For this reason, when the laminated body 30 is heated and heated by the hot press plate 40, the inorganic material-based fiber nonwoven fabric is held together by the organic binder, and the cushioning material 50 is plastically deformed according to the unevenness caused by the wiring pattern 11. To do. For this reason, the packaging material which packs the buffer material 50 is not required, but the in-plane dispersion | variation in the pressure applied to the laminated body 30 can be suppressed.

(Second Embodiment)
A second embodiment of the present invention will be described. In the present embodiment, the heat press plate 40 having a larger planar shape than the laminated body 30 is used as compared with the first embodiment, and the other aspects are the same as those in the first embodiment, and thus the description thereof is omitted here. To do.

  As shown in FIG. 3A, in the present embodiment, the hot press plate 40 and the buffer material 50 having a larger planar shape than the laminate 30 are used. In addition, the planar shape of the hot press board 40 and the buffer material 50 is made into the same magnitude | size. The release paper 60 has a larger planar shape than the hot press plate 40 and the buffer material 50.

  The laminate 30 is configured by laminating four resin films 20, and the length (thickness) of the laminate 30 in the stacking direction is shorter than that of the first embodiment.

  And as FIG.3 (b) shows, it pressurizes and integrates the laminated body 30 from the upper and lower surfaces of a lamination direction. Specifically, the release paper 60 disposed above the laminate 30 and the release paper 60 disposed below the laminate 30 are brought into contact with the side of the laminate 30. In other words, the buffer material 50 disposed above the stacked body 30 and the buffer material 50 disposed below the stacked body 30 are not brought into contact with each other. Thereafter, although not particularly illustrated, the release paper 60 is peeled from the multilayer substrate.

  As described above, in the present embodiment, the hot press plate 40 and the buffer material 50 are larger in planar shape than the laminate 30. For this reason, the outer edge part of the laminated body 30 can also be pressurized reliably, and also the in-plane dispersion | variation in a pressure can be suppressed.

  In addition, since the release paper 60 having a larger planar shape than the buffer material 50 is used, the buffer material 50 disposed above the laminate 30 and the laminate 30 are disposed when the laminate 30 is integrated. It can suppress that the made buffer material 50 contacts. For this reason, it can suppress that a multilayer substrate is covered with the buffer material 50. FIG.

  That is, the buffer material 50 is configured to include an organic binder, and the buffer material 50 is joined when the buffer materials 50 come into contact with each other when the stacked body 30 is integrated. In particular, when the length in the stacking direction of the stacked body 30 is short as in the present embodiment, as shown in FIG. 4A, when a release paper 60 having a smaller planar shape than the cushioning material 50 is used, As shown in FIG. 4B, the buffer members 50 come into contact with each other when the stacked body 30 is integrated. Then, the buffer materials 50 are joined to each other so that the multilayer substrate is covered with the buffer material 50, and it is difficult to peel the buffer material 50 from the multilayer substrate.

  For this reason, the multilayer substrate is covered with the buffer material 50 by using a release paper 60 having a larger planar shape than the buffer material 50 and preventing the buffer materials 50 from contacting each other when the laminated body 30 is integrated. This can be suppressed, and the buffer material 50 can be easily peeled from the multilayer substrate.

(Other embodiments)
In each of the above-described embodiments, the laminated body 30, the heat press plate 40, the buffer material 50, and the release paper 60 have been described as examples having a planar rectangular shape. The shape is not particularly limited.

  In each of the above embodiments, for example, when the outer edge portion of the multilayer substrate is removed, that is, when the outer edge portion of the multilayer substrate does not have to be securely bonded, the planar shape of the hot press plate 40 is laminated. It may be smaller than the planar shape of the body 30. In this case, the planar shape of the buffer material 50 only needs to be larger than the planar shape of the hot press plate 40 and may be larger or smaller than the planar shape of the laminate 30. In addition, when using the thing larger in planar shape than the laminated body 30 as the buffer material 50, by using the thing whose planar shape is larger than the planar shape of the shock absorbing material 50 as the release paper 60 like the said 2nd Embodiment, It is possible to prevent the multilayer substrate from being covered with the buffer material 50 when the laminated body 30 is integrated.

  Furthermore, in each said embodiment, it is good also as the laminated body 30 which equips the both ends of the lamination direction with the resin film 20 which is not provided with the wiring pattern 11, the conductive paste 22, etc. FIG. When the laminated body 30 is configured in this way, all the resin films 20 including the wiring pattern 11 and the conductive paste 22 may be laminated so that the one surface 20a is on the lower side.

DESCRIPTION OF SYMBOLS 11 Wiring pattern 20 Resin film 20a One side 21 Via hole 22 Conductive paste 30 Laminated body 40 Hot press board (press board)
50 cushioning material 60 release paper

Claims (1)

A wiring film (11) is formed on one surface (20a) and a via hole (21) having the wiring pattern as a bottom surface is formed, and a resin film in which a conductive paste (22) is filled in the via hole ( 20) to laminate a plurality of resin films to form a laminate (30);
An arrangement step of disposing the laminate between a pair of press plates (30) and disposing a buffer material (50) between the laminate and the press plate, respectively.
A step of pressing and integrating the laminated body while heating with the press plate from the laminating direction via the cushioning material,
As the cushioning material, using an inorganic material-based fiber nonwoven fabric containing an organic binder ,
In the arrangement step, between each of the cushioning material and the laminate, a pair of release paper having a planar shape as viewed from the lamination direction of the laminate is larger than the cushioning material,
In the step of integrating, the one end of the pair of release papers and the other end of the pair of release papers are spaced apart while the pair of release papers is in contact with the side of the laminate. A method for producing a multilayer substrate.

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