JP2011082428A - Wiring board, multilayer wiring board, and method of manufacturing multilayer wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a multilayer wiring board that satisfies both electric connection by conductive paste and physical connection by resin flow of an adhesive sheet when a wiring board provided with a plurality of connection terminals and wiring for connecting those connection terminals on one surface or both surfaces of a base is connected by an adhesive sheet having, at a predetermined position, a via filled with conductive paste containing at least conductive particles and a curable resin. <P>SOLUTION: The wiring board is provided with the plurality of connection terminals and the wiring for connecting those connection terminals on one surface or both surfaces of the base, and an insulating resin composition layer is provided partially on at least one surface of the base, a wiring surface, and connection terminal surfaces, wherein a maximum thickness of the insulating resin composition layer provided to the connection terminal surfaces is ≤6 μm and a difference between a height of the insulating resin composition on the connection terminals and a height of the insulating resin composition on the base is ≤5 μm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wiring board, a multilayer wiring board, and a manufacturing method thereof.

  In recent years, with the miniaturization and high density of electronic devices, it has been strongly demanded that a multilayer wiring board capable of mounting semiconductor chips such as LSIs with high density be supplied at low cost. In such a multilayer wiring board, it is important to electrically connect a plurality of wiring patterns formed at a fine wiring pitch with high connection reliability.

  In response to such demands for highly accurate and multifunctional electronic devices, conventional wiring boards that perform circuit formation by etching on copper-clad laminates and connect conductors by drilling and plating are no longer required. In order to solve such problems, the multilayer wiring board requires a structure in which a plurality of layers of conductors are connected by inner via holes. Various manufacturing methods corresponding to this, for example, inner wiring, are required. A multilayer wiring board manufacturing method has been proposed in which a conductive paste is used as a via hole to connect conductors. (For example, see Patent Documents 1 and 2)

JP-A-6-268345 JP-A-8-195561

  A method for manufacturing a multilayer wiring board having a four-layer board structure in which a conductive paste is used as an inner via hole for connection between conductors will be described below with reference to FIG. A release film 2 is applied to both surfaces of a prepreg 1 obtained by impregnating and drying a synthetic resin such as an epoxy resin or a polyimide resin on a substrate such as a glass cloth or an aramid fiber cloth as shown in FIG. In addition, a through hole 3 is formed at the predetermined position as shown in FIG.

  Next, the conductive paste 4 is printed on the entire surface of the releasable film 2 to fill the inside of the through hole 3 with the conductive paste 4 as shown in FIG. As shown to e), the release film 2 distribute | arranged to both surfaces of the prepreg 1 is peeled. Thereby, the adhesive sheet 5 with vias in which the conductive paste 4 is disposed only at a predetermined position can be obtained.

  Thereafter, the metal foil 6 is arranged on the surface of the adhesive sheet with via 5 on which the conductive paste is arranged, and the metal foil 6 is electrically connected to each other by being sandwiched between the metal plates and heated and pressed as shown in FIG. obtain. Then, by removing unnecessary portions of the metal foil 6 by etching, a two-layer board 7 (wiring board) shown in FIG.

  Next, as shown in FIG. 1 (h), 5 is disposed on both sides of the two-layer plate 7 and a metal foil 6 is disposed on the outside of the adhesive sheet with vias on which the conductive paste is disposed. To do. Thereafter, the metal plate 6 is sandwiched from both sides, heated and pressurized, and the via-fitted adhesive sheet 5 on which the two-layer plate 7 and the conductive paste are arranged are integrated with the metal foil 6 as shown in FIG. Thereafter, unnecessary portions are eliminated by etching the metal foil 6 to obtain a four-layer plate 9 shown in FIG.

  Bonding with vias filled with conductive paste in place between wiring boards manufactured by conventional methods of circuit formation by etching on copper-clad laminates and connection between conductors by drilling and plating There is also provided a method for manufacturing a high-density multilayer wiring board by arranging sheets, integrating them by heating and pressing, and electrically connecting them.

However, the method of manufacturing the multilayer board by sequentially laminating the adhesive sheets with vias on which the conductive paste is disposed requires time for manufacturing, and the adhesive sheet with vias and the metal foil are arranged on both surfaces of the two-layer board. In the process of etching the metal foil after heating and pressurizing and eliminating unnecessary portions, if the metal foil of the portion that should not be excluded is excluded, there may be a problem that the entire multilayer wiring board becomes defective. is there.
In addition, a method of manufacturing a multilayer board by arranging and laminating via-attached adhesive sheets in which conductive paste is arranged between wiring boards is an adhesive sheet having vias filled with conductive paste in a predetermined place on a wiring board When integrated with heat and pressure, poor electrical connection due to the conductive paste may occur, or there may be physical connection failure that causes a gap between the adhesive sheet and the wiring board. It was. Therefore, it is easy to manufacture, and it is a problem to achieve both electrical connection and physical connection.

  The present invention solves the above-described problem. A wiring board in which a plurality of connection terminals and wirings connecting the connection terminals are provided on one or both surfaces of a substrate surface are formed by using conductive particles and a curable resin. It is possible to achieve both electrical connection with conductive paste and physical connection with resin flow of adhesive sheet when connecting via adhesive sheet that has at least a via filled with conductive paste in place A method for manufacturing a multilayer wiring board is proposed.

The present invention relates to the following.
(1) A wiring board in which a plurality of connection terminals and wirings connecting the connection terminals are provided on one or both surfaces of the substrate surface, and at least one substrate surface on one side and the wiring surface and the connection terminal surface A wiring board in which an insulating resin composition layer is provided at a portion, and a maximum thickness d1 of the insulating resin composition layer provided on the surface of the connection terminal is 6 μm or less.
(2) The wiring board according to (1), wherein the maximum height difference d2 on the surface of the insulating resin composition layer is 5 μm or less.
(3) A multilayer wiring board in which a plurality of wiring boards are electrically connected by an adhesive sheet having vias filled with a conductive paste containing at least conductive particles and a curable resin at predetermined locations, and the wiring boards A multilayer wiring board in which at least one of the wiring board is the wiring board according to (1) or (2), and a surface having a maximum thickness d1 of an insulating resin composition layer provided on the surface of the connection terminal of 6 μm or less is in contact with the sheet.
(4) A release film is bonded to at least one surface of the adhesive sheet, and then the sheet and the release film penetrate through the sheet and the release film in a thickness direction at a predetermined position of the adhesive sheet to which the release film is bonded. Open a hole, fill the through-hole with a conductive paste containing at least conductive particles and a curable resin, then remove the release film, and then heat and press the circuit board on both sides of the sheet. A method of manufacturing a multilayer wiring board to be processed, wherein at least one of the wiring boards is the wiring board described in (1) or (2), and the maximum thickness d1 of the insulating resin composition layer provided on the surface of the connection terminal is A method for producing a multilayer wiring board, wherein the sheet is superposed on a surface side of 6 μm or less.

  According to the present invention, a wiring board in which a plurality of connection terminals and wirings connecting the connection terminals are provided on one or both surfaces of a substrate surface are filled with a conductive paste containing at least conductive particles and a curable resin. A stable electrical connection between the wiring boards by the conductive paste when connecting with the adhesive sheet having a predetermined position, and a gap in the insulating resin composition between the wiring boards by the resin flow of the adhesive sheet is generated It is possible to implement a balance with stable physical connection without any problems.

It is sectional drawing which shows the manufacturing process of the multilayer printed wiring board of the conventional 4 layer board structure. It is sectional drawing of a wiring board in the case of having an insulating resin composition layer on one side of the present invention. It is a wiring board cross-sectional enlarged view in the case of having an insulating resin composition layer on one side of the present invention. It is sectional drawing which shows the manufacturing method of the multilayer wiring board which becomes one Example of this invention.

The cross-sectional structure of the wiring board of the present invention will be described below with reference to FIGS. 2 is a cross-sectional view of the wiring board, and FIG. 3 is an enlarged view thereof.
The wiring board of the present invention is composed of a connection terminal 12, wiring (not shown), an insulating resin composition layer 10, and the like on one side or both sides of a substrate 11. The basic structure of this wiring board is called a general multilayer wiring board, and the interlayer connection may be by plating or by conductive paste. For example, a through-hole wiring board or a build-up wiring board.
The base material, connection terminal, and wiring constituting the wiring board of the present invention may be of the material and shape used in general wiring boards.
The base material is a material used for a general multilayer wiring board, for example, a woven fabric or non-woven fabric impregnated with a thermosetting resin composition and cured. Examples of the thermosetting resin composition include an epoxy resin and phenol. Resin, polyimide resin, bismaleimide resin and the like can be used, and glass cloth, glass paper, amide cloth, amide paper and the like can be used as the woven or non-woven fabric.
The connection terminal is a metal terminal for electrical connection with other multilayer wiring boards and semiconductor elements, and is electrically connected with solder balls, conductive paste, or the like.
The wiring is a conductor that electrically connects the connection terminals.

One of the features of the wiring board of the present invention is that an insulating resin composition layer is provided on at least one surface of the wiring board so as to cover a part of the substrate surface, the wiring surface, and the connection terminal surface.
In the present invention, the surface of the connection terminal means not a side surface of the terminal (a surface perpendicular or substantially perpendicular to the substrate) but a surface in contact with the outside that is parallel or substantially parallel to the substrate surface. That is, the insulating resin layer 10 is provided so as to cover the upper portion of the connection terminal 12 as shown in FIG. At this time, the substrate surface, the wiring surface (including side surfaces) and the connection terminals are all covered with the insulating resin composition layer.

An important feature of the present invention is the maximum thickness (d1 in FIG. 3) of the insulating resin layer covering the surface of the connection terminal. By adjusting d1, an adhesive sheet having vias filled with a conductive paste in a predetermined place is provided. It is possible to provide a wiring board that is excellent in connectivity (electrical and physical connection) when used as a wiring board that is integrated and connected by heating and pressing. The connectivity also depends on the protruding height of the conductive paste to be connected, and the larger the protruding height, the higher the connection reliability tends to be. However, from the viewpoint of manufacturing, it is preferable that the protruding height is small. If the protruding height is large, the protruding portion of the conductive paste may be removed in the step of peeling the release film. At present, considering the connection reliability, the protruding height of the conductive paste is generally 20 μm or more, and cannot be extremely increased from the viewpoint of manufacturing. If good connection can be obtained when the protruding height of the conductive paste is 20 μm, sufficiently good connection can be obtained when the protruding height is more than that, and a via filled with the conductive paste can be obtained. When using an adhesive sheet with a via filled with a general conductive paste in place as a wiring board to which an adhesive sheet having a predetermined place is arranged and connected by heating and pressing, the conductive sheet It can be used without depending on the protruding height of the paste.
As a result of continuing intensive studies from such a viewpoint, the present inventors have found that the maximum thickness (d1 in FIG. 3) of the insulating resin layer covering the connection terminal surface needs to be 6 μm or less. . As a result, it has been found that when an adhesive sheet having vias filled with a conductive paste is arranged in a predetermined place and used as a wiring board to be connected integrally by heating and pressing, it is excellent in electrical and physical connection. It was.
Furthermore, the maximum height difference (d2 in FIG. 3) on the surface of the insulating resin composition layer is preferably 5 μm or less from the viewpoint of improving physical connectivity.
d1 and d2 tend to depend on the thickness of the film or sheet used to form the insulating resin composition layer. When the thickness of the film is thick, d1 increases, and when it is thin, d2 increases. Otherwise, d1 and d2 do not fall within the scope of the present invention.

  The insulating resin composition layer is preferably made of a resin composition having a resin flow of 5000 Pa · s or less during heating and pressurization. Thereby, it becomes easy to adjust d1 to 6 μm or less and to adjust d2 to 5 μm or less. Further, for example, a photosensitive solder resist or an insulating resin adhesive sheet used for manufacturing a wiring board can be used. As the photosensitive solder resist, those generally used for semiconductor device mounting package substrates and wiring boards can be used. As such, a dry film type FOTEC FZ-2500G (Hitachi Chemical Industry Co., Ltd., trade name) can be used. In addition, as the insulating resin adhesive sheet, an epoxy or polyimide system generally used for a semiconductor element package substrate or a wiring board can be used. As such an adhesive sheet, an adhesive sheet in which a thermosetting resin composition is applied on a polyethylene terephthalate film, and heated and dried to form a film can be used. As the thermosetting resin composition, epoxy resin, phenol resin, polyimide resin, bismaleimide resin and the like can be used. The sheet forming the insulating resin composition layer is preferably a sheet having a thickness equal to or greater than the thickness of the connection terminal, and more preferably about 5 μm thicker than the connection terminal thickness. For example, if the connection terminal thickness is 20 μm, an insulating resin composition having a thickness of 25 μm is used. As a method for forming the connection terminal, for example, in the case of a dry film type solder resist, after being crimped using a vacuum laminator, It can be formed by exposure, development, and full cure, which are solder resist processing steps. Further, when an insulating resin adhesive sheet is used, it can be formed by using a vacuum laminator or a vacuum press machine and crimping to the surface of the multilayer wiring board and removing the resin on the surface of the connection terminal by laser processing or the like. Even when d1 is 6 μm or more, d1 can be 6 μm or less and d2 can be 5 μm or less by polishing the surface using buffing or the like. As a result, the surface of the substrate is flattened, and by placing the flattened surface on the side of the adhesive sheet filled with the conductive paste, the conductive paste is not affected by the thickness of the connection terminal. The filled adhesive sheet can easily achieve both electrical connection between the wiring boards and physical connection of the insulating resin composition between the wiring boards by resin flow of the adhesive sheet. When d1 exceeds 6 μm, the electrical connection between the conductive paste and the connection terminal surface becomes unstable.

  The adhesive sheet having a through hole filled with the conductive paste of the present invention can use an epoxy or polyimide-based adhesive for multilayering, and a plurality of wiring boards can be bonded together by pressing or laminating. Can do. As such an adhesive, for example, a thermosetting resin composition is impregnated into a woven or non-woven fabric, heated and dried, and applied to a semi-cured prepreg or a polyethylene terephthalate film. Then, an adhesive sheet that is heated and dried to form a film can be used. As the thermosetting resin composition, an epoxy resin, a phenol resin, a polyimide resin, a bismaleimide resin, or the like can be used. As the woven or non-woven fabric, glass cloth, glass paper, amide cloth, amide paper, or the like can be used.

  The adhesive material is preferably an elastomer material. Thereby, since the elastomer material as an adhesive agent can absorb the distortion produced by the difference in the dimensional behavior of a plurality of wiring boards, it becomes possible to suppress the warp of the laminated multilayer wiring boards. In particular, when materials and thicknesses of a plurality of wiring boards to be bonded are different, the dimensional behavior of the wiring boards at the time of manufacture and use is different, so an elastomer material is used as an adhesive used for bonding a plurality of wiring boards. Is effective. As such an adhesive, for example, AS-2600W (manufactured by Hitachi Chemical Co., Ltd., trade name) can be used.

  The conductive paste provided on the adhesive sheet of the present invention comprises at least one conductive metal (for example, gold, silver, copper, palladium, tin, nickel, etc.) and an epoxy resin, a phenol resin, a polyimide resin, and the like as a conductive component. It is desirable to form from at least one thermosetting resin selected from acrylic resins.

  The adhesive sheet of the present invention is a prepreg obtained by impregnating a thermosetting resin composition into a woven or non-woven fabric, or a release sheet using a press or a laminate on at least one side of a resin sheet semi-cured from the thermosetting resin composition. A through-hole is formed in a state where the adhesive film is bonded. Although there is no restriction | limiting in particular in the thickness of an adhesive sheet, It is desirable that they are 30 micrometers or more and 100 micrometers or less. When the thickness is less than 30 μm, there is a high risk that the conductive paste to be filled later will be peeled off from the through hole when the release film is peeled off. On the other hand, when the thickness is larger than 100 μm, it is difficult to sufficiently fill the through holes with a conductive paste to be filled later. The thickness of the release film used is 20 μm or more. When the thickness is 20 μm or less, even when d1 is adjusted to 6 μm or less, the protruding height of the conductive paste is low, and the conductive paste is insufficiently compressed when bonding a plurality of wiring boards. The connection is likely to be unstable. Furthermore, the thickness of the releasable film is preferably 50 μm or less. In the case of 50 μm or more, when the release film is peeled off from the adhesive sheet, a part of the conductive paste to be filled in the next step is taken together with the release film, and a plurality of wiring boards are bonded together. There is a possibility that the conductive paste becomes insufficiently compressed and the electrical connection becomes unstable. It is further desirable to select an appropriate thickness depending on the thickness of the adhesive sheet to be used and the diameter of the through hole. In addition, as such a releasable film, for example, Fine Peel 500NC (trade name, manufactured by Reiko Co., Ltd.) can be used. Although there is no restriction | limiting in particular in formation of a through-hole, It is desirable to carry out from the side by which the release film was stuck by the carbon dioxide laser. The conductive paste is filled from the side on which the release film is pasted by screen printing or the like. Thereby, it is possible to fill the conductive paste only in the through holes formed in the adhesive sheet. After filling with the conductive paste, by removing the releasable film attached to the surface of the adhesive sheet, the conductive paste is not attached to any part other than the through holes, and the releasability from the surface of the adhesive sheet. An adhesive sheet formed with a conductive paste having a shape in which the conductive paste protrudes by the thickness of the film can be obtained. In addition, when it becomes a wiring board, an adhesive sheet and an electrically conductive paste harden | cure, and the electrical connection of the upper surface lower surface of an adhesive sheet is attained by the metal powder in an electrically conductive paste.

  The manufacturing method of the multilayer wiring board of this invention is demonstrated below, using FIG. The adhesive sheet with vias of the present invention is disposed between the wiring boards of the present invention. Moreover, the direction of the wiring board of this invention is arrange | positioned so that the insulating resin composition layer formed so that it may become in the said conditions turns into an adhesive sheet side. Thus, after arrange | positioning each wiring board and an adhesive sheet, a multilayer wiring board as shown in FIG.4 (b) can be manufactured by heating and pressurizing using means, such as a press. Further, as shown in FIG. 4 (b '), three or more multilayer wiring boards can be manufactured using two or more adhesive sheets with vias.

Hereinafter, the present invention will be described in detail with reference examples and examples. In addition, this invention is not restrict | limited to a following example.
Example 1
[Production of wiring board provided with insulating resin composition layer]

  MARK- which is an NC drill machine on MCL-E-679FG (trade name, manufactured by Hitachi Chemical Co., Ltd.), which is a 0.6 mm thick epoxy resin glass cloth copper clad laminate with 12 μm thick copper foil bonded together 20 (manufactured by Hitachi Via Mechanics Co., Ltd., product name) was used to form a through hole with a diameter of 0.2 mm, and then the inner wall of the hole was cleaned with an aqueous sodium permanganate solution at a temperature of 50 degrees for 15 minutes. L-59 (manufactured by Hitachi Chemical Co., Ltd., trade name), copper sulfate 10 g / L, EDTA 40 g / L, formalin 10 ml / L, PH 12.2 at a temperature of 70 ° C. and a time of 8 hours. The copper foil surface and the inner wall of the hole were subjected to 15 μm copper plating.

  Next, PHP-900IR-1 (trade name, manufactured by Yamaei Chemical Co., Ltd.), which is a permanent hole-filling ink, is filled inside the hole, and then a UV-curable etching resist dry film H-9025K (Hitachi) is formed on both surfaces of the substrate. Kasei Kogyo Co., Ltd., trade name) is pressure-bonded using a roll laminator under the conditions of pressure 0.2 MPa, temperature 110 ° C., speed 1.5 m / min, and then a negative mask is bonded to the surface and irradiated with ultraviolet rays. After the circuit pattern is baked and developed by spraying a 1% sodium carbonate aqueous solution to form an etching resist, the exposed copper portion without the etching resist is sprayed and sprayed with ferric chloride, hydrochloric acid, sulfuric acid / hydrogen peroxide. Etching is performed with ferric chloride etching solution composed of the composition under the conditions of pressure 0.1 MPa and speed 4.3 m / min. Further the etching resist was removed by spraying a 3% sodium hydroxide solution, to form a wiring. At that time, the connection terminal diameter was set to φ0.5 mm.

  Next, HIST-7300 (manufactured by Hitachi Chemical Co., Ltd., trade name) is used, pre-bonding treatment is performed by roughening the copper surface at a spray pressure of 0.1 MPa and a speed of 4.0 m / min, and then UV curable. Solder resist dry film FZ-2500G (trade name, manufactured by Hitachi Chemical Co., Ltd.) 25 μm was used with a vacuum laminator MVLP-500 (trade name, manufactured by Meiki Seisakusho Co., Ltd.), temperature 80 ° C., pressure 0.4 MPa. Then, pressure bonding is performed for 30 seconds, and then a negative mask is laminated on the surface, irradiated with 400 mJ of ultraviolet light, further developed by spray spraying with a 1.5% sodium carbonate aqueous solution, and further cured by irradiation with 1 J of ultraviolet light. And dried at 160 ° C. for 60 minutes to form an insulating resist. At that time, the opening diameter of the solder resist was set to φ0.4 mm. HIST-7300 (manufactured by Hitachi Chemical Co., Ltd., trade name) was used, and adhesion pretreatment was performed by roughening the copper surface at a spray pressure of 0.1 MPa and a speed of 4.0 m / min.

[Preparation of adhesive sheet with vias]
AS-2600W (trade name, manufactured by Hitachi Chemical Co., Ltd.), which is an adhesive sheet having a thickness of 50 μm, a width of 518 mm, and a length of 454 mm, has a releasability of 21 μm in thickness, 520 mm in width, and 462 mm in length. Fine peel 500NC (trade name, manufactured by Reiko Co., Ltd.), a film, and MVLP-500 (trade name, manufactured by Meiki Seisakusho Co., Ltd.), a vacuum laminator, were used at a temperature of 60 ° C., a pressure of 0.5 MPa, and a time of 30 seconds. Under the conditions, the surface resin component of the adhesive sheet was melted and pasted. Next, using a laser processing machine H · MARK-30L (trade name, manufactured by Hitachi Via Mechanics Co., Ltd.), a through-hole is formed in a predetermined place under the condition that the releasable film opening diameter of the laser light irradiation surface is 150 μm. Formed. Next, the entire surface of the conductive paste was printed with the laser light irradiation surface facing up, and the conductive paste was filled into the through holes.

[Production of multilayer wiring boards]
Both sides of the release film of the adhesive sheet with vias produced by the above method are peeled off, and the insulating resin composition layer on the side of the adhesive sheet with vias is provided on the wiring board provided with two insulating resin composition layers so as to sandwich the film. Are aligned by a pin lamination method, sandwiched between 1 mm thick metal plate DP-2 (trade name, manufactured by Taika Kogyo Co., Ltd.), stacked in five layers, and an initial temperature of 30 ° C. Was inserted through a cushion board R-225RX (manufactured by Kinyo Co., Ltd., trade name) between hot plates of No. 140, heated and pressurized in vacuum at a temperature of 200 ° C. and a pressure of 5 MPa for 140 minutes, and taken out after cooling. .

(Comparative Example 1)
[Production of wiring board provided with insulating resin composition layer]
The insulating resin composition layer was prepared in the same manner as in the example except that a 30 μm thick UV-curable solder resist dry film FZ-2500G (trade name, manufactured by Hitachi Chemical Co., Ltd.) 5 μm thicker than the example was used.

[Preparation of adhesive sheet with vias]
It produced similarly to the Example.

[Production of multilayer wiring boards]
It produced similarly to the Example.

(Comparative Example 2)
[Production of wiring board provided with insulating resin composition layer]
It produced similarly to the Example except having used 25 micrometer dry film PFR-800AUS402 (Taiyo Ink Co., Ltd. product name) for ultraviolet curing type solder resist as an insulating resin composition layer.

[Preparation of adhesive sheet with vias]
It produced similarly to the Example.

[Production of multilayer wiring boards]
It produced similarly to the Example.

(Comparative Example 3)
[Production of wiring board provided with insulating resin composition layer]
The solder resist was prepared in the same manner as in the example except that the opening diameter of the solder resist was set to φ0.6 mm.

[Preparation of adhesive sheet with vias]
It produced similarly to the Example.

[Production of multilayer wiring boards]
It produced similarly to the Example.

(Comparative Example 4)
[Production of wiring board provided with insulating resin composition layer]
It produced similarly to the Example except not having apply | coated the soldering resist.

[Preparation of adhesive sheet with vias]
It produced similarly to the Example.

[Production of multilayer wiring boards]
It produced similarly to the Example.

  About the Example and the comparative example, the connection reliability test was done, cross-section observation was conducted after that, the presence or absence of a void was confirmed, and the insulation resin composition layer thickness d1 and d2 on a connection terminal and a base material were measured.

[Connection reliability test]
After performing dehumidification treatment at 125 ° C. for 2 hours using the substrates prepared in Examples and Comparative Examples, reflow treatment at 260 ° C. for 10 seconds or more was performed five times, and connection resistance meter 3541 RESISTANCE HiTESTER (Hioki Electric Co., Ltd.) Substrate connection resistance was measured using the product name. A connection resistance value that was increased by 20% or more compared to the initial value (before drying at 125 ° C. for 2 hours) was regarded as rejected.

  Table 2 shows the results. In the example, there was no void, the initial resistance value was small, and the connection reliability was OK. In Comparative Examples 1 and 2, compared with the Example, there was no void, but the initial resistance value was large and the connection reliability was NG. In Comparative Examples 3 and 4, generation of voids was observed around the opening of the solder resist.

（参考例）
ビア付き接着シートを作成の離型フィルムを通常より薄く調整したものと銅箔を使用し、ｄ１の値を検討した。
［ビア付接着シートの作製］
厚さが５０μｍ、幅が５１８ｍｍ、長さ４５４ｍｍの接着シートであるＡＳ−２６００Ｗ（日立化成工業株式会社製、商品名）の両面に厚さが１１μｍ，幅が５２０ｍｍ、長さ４６２ｍｍの離型性フィルムであるファインピール５００ＮＣ（株式会社麗光製、商品名）または、厚さが１４μｍ，幅が５２０ｍｍ、長さ４６２ｍｍの離型性フィルムであるファインピール５００ＮＣ（株式会社麗光製、商品名）を真空ラミネーターであるＭＶＬＰ−５００（株式会社 名機製作所製、商品名）を用い、温度６０℃、圧力０．５ＭＰａ、時間３０秒の条件で圧着し、接着シートの表面樹脂成分を溶融させて貼り付けた。次いで、レーザー加工機であるＨ・ＭＡＲＫ−３０Ｌ（日立ビアメカニクス株式会社製、商品名）を用いてレーザー光照射面の離型性フィルム開口径が１５０μｍとなる条件にて所定の場所に貫通孔を形成した。次いで、レーザー光照射面を上にした状態で導電性ペーストを全面印刷し、貫通孔内に導電性ペーストを充填した。
［多層配線板の作製］
上記方法により作製したビア付接着シートの離型性フィルムを両面とも剥離し、これを挟み込むように２枚の銅箔ではさみ、厚さ１ｍｍの金属板ＤＰ−２（太華工業株式会社製、商品名）で挟み、これを５段重ね合わせ、初期温度３０℃の加熱プレスの熱盤間にクッションボードＲ−２２５ＲＸ（株式会社 金陽社製、商品名）を介し挿入し、真空中で温度２００℃、圧力５ＭＰａの条件にて１４０分間加熱加圧し、冷却後取り出した。次いで、基板両表面に、紫外線硬化型エッチングレジスト用ドライフィルムＨ−９０２５Ｋ（日立化成工業株式会社製、商品名）をロールラミネーターを用い、圧力０．２ＭＰａ、温度１１０℃、速度１．５ｍ／ｍｉｎの条件で圧着し、次いでその表面にネガ型マスクを張り合わせ、紫外線を照射し、回路パターンを焼付け、１％の炭酸ナトリウム水溶液のスプレー噴霧によって現像し、エッチングレジストを形成した後、そのエッチングレジストの無い銅露出部分をスプレー噴霧によって、塩化第二鉄、塩酸、硫酸過水の組成からなる塩化第二鉄エッチング液で圧力０．１ＭＰａ、速度４．３ｍ／ｍｉｎの条件でエッチングを行い、さらに３％水酸化ナトリウム水溶液の噴霧によってエッチングレジストを除去し、配線を形成した。
初期抵抗値及び初期抵抗値のバラツキを評価した。

(Reference example)
The value of d1 was examined by using a release film for preparing an adhesive sheet with vias, which was adjusted to be thinner than usual, and copper foil.
[Preparation of adhesive sheet with vias]
AS-2600W (trade name, manufactured by Hitachi Chemical Co., Ltd.), an adhesive sheet having a thickness of 50 μm, a width of 518 mm, and a length of 454 mm, has a releasability of 11 μm, width of 520 mm, and length of 462 mm. Fine peel 500NC (trade name, manufactured by Reiko Co., Ltd.) which is a film, or fine peel 500NC (trade name, manufactured by Reiko Co., Ltd.) which is a releasable film having a thickness of 14 μm, a width of 520 mm and a length of 462 mm Is bonded using a vacuum laminator MVLP-500 (trade name, manufactured by Meiki Seisakusho Co., Ltd.) at a temperature of 60 ° C., a pressure of 0.5 MPa, and a time of 30 seconds to melt the surface resin component of the adhesive sheet. Pasted. Next, using a laser processing machine H · MARK-30L (trade name, manufactured by Hitachi Via Mechanics Co., Ltd.), a through-hole is formed in a predetermined place under the condition that the releasable film opening diameter of the laser light irradiation surface is 150 μm. Formed. Next, the entire surface of the conductive paste was printed with the laser light irradiation surface facing up, and the conductive paste was filled into the through holes.
[Production of multilayer wiring boards]
The release film of the adhesive sheet with vias prepared by the above method is peeled off on both sides, and sandwiched between two copper foils so as to sandwich this, and a metal plate DP-2 having a thickness of 1 mm (manufactured by Taika Kogyo Co., Ltd., (Product name), 5 layers are stacked, and inserted between the hot plates of a heating press with an initial temperature of 30 ° C. via a cushion board R-225RX (trade name, manufactured by Kinyo Co., Ltd.), and the temperature is 200 ° C. in a vacuum. The mixture was heated and pressurized for 140 minutes under the condition of a pressure of 5 MPa, taken out after cooling. Next, a UV laminating etching resist dry film H-9025K (manufactured by Hitachi Chemical Co., Ltd., trade name) is applied to both surfaces of the substrate using a roll laminator, pressure 0.2 MPa, temperature 110 ° C., speed 1.5 m / min. Then, a negative mask is laminated on the surface, irradiated with ultraviolet rays, the circuit pattern is baked, developed by spraying with a 1% sodium carbonate aqueous solution, and an etching resist is formed. Etching is performed on the exposed copper exposed portion by spraying with a ferric chloride etching solution composed of ferric chloride, hydrochloric acid, and sulfuric acid / hydrogen peroxide under the conditions of a pressure of 0.1 MPa and a speed of 4.3 m / min. The etching resist was removed by spraying with a sodium hydroxide aqueous solution to form a wiring.
The initial resistance value and the variation in the initial resistance value were evaluated.

この結果、表１に示すように離型性フィルム２の厚みが１４μｍと比較し、１１μｍとなると初期抵抗値及びバラツキが大きくなる事が分かった。この事より、安定した電気的接続を確保する為には、ビア付接着シートから突出するビアの高さを、最低１４μｍ確保する事が必要であることが分かった。つまり、通常使用する離型性フィルム厚みが２０μｍまたはそれ以上であり、最低必要なビア突出高さが１４μｍであることを考慮すると、本検討の結果からもｄ１の最大値は６μｍとなる。

As a result, as shown in Table 1, it was found that when the thickness of the releasable film 2 was 11 μm, the initial resistance value and the variation were increased. From this, it has been found that in order to ensure stable electrical connection, it is necessary to secure a minimum height of 14 μm of the via protruding from the adhesive sheet with via. In other words, considering that the normally used release film thickness is 20 μm or more and the minimum required via protrusion height is 14 μm, the maximum value of d1 is 6 μm also from the result of this study.

DESCRIPTION OF SYMBOLS 1 Prepreg 2 Release film 3 Through-hole 4 Conductive paste 5 Adhesive sheet with via 6 Metal foil 7 Two-layer board (two-layer printed wiring board)
8 4 layer shield plate 9 4 layer plate (4 layer printed wiring board)
DESCRIPTION OF SYMBOLS 10 Insulating resin composition layer 11 Base material 12 Connection terminal 13 Wiring board 14 provided with insulating resin composition layer Multilayer wiring board

Claims (4)

  A wiring board in which a plurality of connection terminals and wirings connecting the connection terminals are provided on one or both surfaces of the base material surface, and insulated at least on one side of the base material surface and the wiring surface and a part of the connection terminal surface A wiring board in which a resin composition layer is provided and a maximum thickness d1 of an insulating resin composition layer provided on the surface of the connection terminal is 6 μm or less.   The wiring board according to claim 1, wherein the maximum height difference d2 on the surface of the insulating resin composition layer is 5 μm or less.   A multilayer wiring board in which a plurality of wiring boards are electrically connected by an adhesive sheet having vias filled with a conductive paste containing at least conductive particles and a curable resin at a predetermined place, and at least one of the wiring boards The multilayer wiring board according to claim 1 or 2, wherein a surface having a maximum thickness d1 of an insulating resin composition layer provided on the surface of the connection terminal of 6 μm or less is in contact with the sheet.   A release film is bonded to at least one surface of the adhesive sheet, and then a through-hole that penetrates the sheet and the release film in the thickness direction is opened at a predetermined position of the adhesive sheet to which the release film is bonded. A multilayer in which the through-holes are filled with a conductive paste containing at least conductive particles and a curable resin, then the release film is removed, and then a wiring board is superposed on both sides of the sheet and heat-pressed. A method for manufacturing a wiring board, wherein at least one of the wiring boards is the wiring board according to claim 1 or 2, and the maximum thickness d1 of the insulating resin composition layer provided on the surface of the connection terminal is 6 μm or less. A method of manufacturing a multilayer wiring board in which the sheet is overlaid on the substrate.

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