JP4641588B2 - Capacitor and multilayer printed wiring board - Google Patents

Description

【０１８１】
【表２】

【０１８２】
表１に示したように、実施例１〜５で得られた多層プリント配線板について、１０００サイクルのヒートサイクル試験を行った場合、コンデンサと接着剤と間での剥離は発生しておらず、接着剤中にもクラックは発生していなかった。
また、短絡や断線、層間樹脂絶縁層の膨れも発生していなかった。
【０１８３】
また、２０００サイクルのヒートサイクル試験を行った場合には、実施例３で得られた多層プリント配線板では、誘電体表面の一部で、コンデンサと接着剤と間での剥離が発生しており、接着剤中にもわずかにクラックが発生していたが、製品に影響を与える程のものではなく、短絡や断線、層間樹脂絶縁層の膨れは発生していなかった。
また、実施例４で得られた多層プリント配線板では、金属層表面の一部で、コンデンサと接着剤と間での剥離が発生しており、接着剤中にもわずかにクラックが発生していたが、製品に影響を与える程のものではなく、短絡や断線、層間樹脂絶縁層の膨れは発生していなかった。
【０１８４】
また、実施例１、２および５で得られた多層プリント配線板では、コンデンサと接着剤と間での剥離は発生しておらず、接着剤中にもクラックは発生していなかった。
また、この場合でも、短絡や断線、層間樹脂絶縁層の膨れも発生していなかった。
【０１８５】
さらに、表２に示したように、実施例１〜５で基板に埋設したコンデンサは、信頼性試験の前後で静電容量に変化が少なく、導体回路−コンデンサの間においても、電気的接続による影響が殆どない。
【０１８６】
【発明の効果】
以上説明したように、第一の本発明のコンデンサは、その表面の少なくとも一部の接触角が７〜４５°であるため、多層プリント配線板の基板に内蔵された場合には、内蔵させる際に用いた接着剤との密着性が高く、コンデンサと接着剤との間で剥離が発生したり、該接着剤にクラックが発生したりすることがなく、多層プリント配線板に内蔵するコンデンサとして好適である。
【０１８７】
また、第二の本発明のコンデンサは、その表面の少なくとも一部にコーティング層が形成されているため、多層プリント配線板の基板に内蔵された場合には、内蔵させる際に用いた接着剤との密着性が高く、コンデンサと接着剤との間で剥離が発生したり、該接着剤にクラックが発生したりすることがなく、多層プリント配線板に内蔵するコンデンサとして好適である。
【０１８８】
また、本発明の多層プリント配線板は、コンデンサが内蔵されているため、ＩＣチップとコンデンサとの距離が短く、高周波数で駆動するＩＣチップを実装した場合でもループインダクタンスが充分低い。
さらに、内蔵されるコンデンサは、第一または第二の本発明のコンデンサであり、プラズマ処理、酸処理、洗浄処理等が施されていたり、コーティング層が形成されていたりするため、コンデンサと接着剤との間で剥離が発生したり、該接着剤にクラックが発生したりすることがない。そのため、上記多層プリント配線板は、コンデンサの端子とバイアホールとの間の接続が遮断されたり、層間樹脂絶縁層に膨れが生じたりすることがなく、電気的接続性、信頼性に優れる。
【図面の簡単な説明】
【図１】（ａ）〜（ｂ）は、本発明のカーボンの一例を模式的に示す断面図である。
【図２】本発明の多層プリント配線板の一例を模式的に示す断面図である。
【図３】図２に示す多層プリント配線板にＩＣチップを実装し、ドータボードに取り付けた状態を模式的に示す断面図である。
【図４】（ａ）〜（ｄ）は、本発明の多層プリント配線板の製造工程を模式的に示す断面図である。
【図５】（ａ）〜（ｃ）は、本発明の多層プリント配線板の製造工程を模式的に示す断面図である。
【図６】（ａ）〜（ｃ）は、本発明の多層プリント配線板の製造工程を模式的に示す断面図である。
【図７】（ａ）〜（ｃ）は、本発明の多層プリント配線板の製造工程を模式的に示す断面図である。
【図８】（ａ）〜（ｃ）は、本発明の多層プリント配線板の製造工程を模式的に示す断面図である。
【図９】本発明の多層プリント配線板の別の一例を模式的に示す断面図である。
【図１０】（ａ）〜（ｄ）は、本発明の多層プリント配線板の製造工程を模式的に示す断面図である。
【図１１】（ａ）〜（ｃ）は、本発明の多層プリント配線板の製造工程を模式的に示す断面図である。
【図１２】（ａ）〜（ｃ）は、本発明の多層プリント配線板の製造工程を模式的に示す断面図である。
【図１３】本発明の多層プリント配線板の更に別の一例を模式的に示す断面図である。
【図１４】（ａ）〜（ｄ）は、本発明の多層プリント配線板の製造工程を模式的に示す断面図である。
【図１５】（ａ）、（ｂ）は、従来の多層プリント配線板のループインダクタンスの説明図であり、（ｃ）は、本発明の多層プリント配線板のループインダクタンスの説明図である。
【符号の説明】
１０、１１０、２１０ 多層プリント配線板
２０、１２０、２２０ コンデンサ
２１ 第１電極
２２ 第２電極
２３ 誘電体
２４ 第１導電膜
２５ 第２導電膜
２６、２２６、３２６ 金属層
２７、２２７、３２７ 粗面
３０ 基板
４０、６０ 層間樹脂絶縁層
４６、６６ バイアホール
４８、６８ 導体回路
７０ ソルダーレジスト層
７６ 半田バンプ
９０ ＩＣチップ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a capacitor incorporated in a multilayer printed wiring board and a multilayer printed wiring board incorporating the capacitor.
[0002]
[Prior art]
Conventionally, in a printed wiring board for a package substrate, a chip capacitor is surface-mounted in order to reduce loop inductance from the power source to the power source / ground of the IC chip. That is, the loop inductance that causes transmission loss is the wiring length from the power supply terminal 192P of the IC chip 190 shown in FIG. 15A to the power supply via the power supply line in the printed wiring board 300 and the power supply to the printed wiring board 300. It is proportional to the wiring length between the ground terminals 192E of the IC chip 190 via the ground wire. For this reason, as shown in FIG. 15B, a chip capacitor 200 is surface-mounted on a printed wiring board 300, and a chip capacitor is interposed between the power supply and the power supply terminal / ground terminal of the IC chip. Can be shortened as shown by the solid line in the figure.
[0003]
However, since the reactance of the loop inductance depends on the frequency, even if the chip capacitor is mounted on the surface of the multilayer printed wiring board as the IC chip drive frequency increases, the loop inductance is sufficiently reduced. I can't do that.
[0004]
[Means for Solving the Problems]
Therefore, the present inventors have conducted extensive research to further reduce the loop inductance from the power source to the power source / ground of the IC chip, and as a result, have found that a capacitor may be built in the multilayer printed wiring board. In addition, an interlayer resin insulation layer and a conductor circuit are sequentially formed on a substrate on which a capacitor is built-in or housed (hereinafter also referred to simply as “built-in”), and the electronic component, the conductor circuit, and We proposed a multilayer printed circuit board in which upper and lower conductor circuits are connected via via holes.
In such a multilayer printed wiring board, the distance between the IC chip and the capacitor is shorter than when the capacitor is mounted on the surface, and the loop inductance is sufficiently low even when the IC chip driven at a high frequency is mounted. .
[0005]
In the multilayer printed wiring board, a cavity for incorporating a capacitor such as a counterbore (concave portion) or a through-hole is provided in the substrate, and the capacitor is attached in the cavity via an adhesive. An interlayer resin insulation layer and a conductor circuit are formed on both surfaces of the substrate in which the capacitor is incorporated, and a via hole is provided between the capacitor connection terminal, the upper conductor circuit, and the upper and lower conductor circuits via the interlayer resin insulation layer. Connected through.
[0006]
However, a conventional multilayer printed wiring board mounting capacitor is manufactured for surface mounting, and usually only one surface of the capacitor contacts the surface of the multilayer printed wiring board, and the capacitor is built in the substrate. The usage pattern was not supposed. Therefore, the surface state of the capacitor is usually not uniform, and foreign matter such as oil is present. Therefore, when the capacitor is built in the substrate, the surface state is non-uniform. There is a problem that peeling occurs between the adhesive and the adhesive or cracks occur in the adhesive. In this case, the connection between the capacitor terminal and the via hole is interrupted, or the interlayer resin insulation layer is swollen, which causes a decrease in the electrical connectivity and reliability of the multilayer printed wiring board. It was.
[0007]
In addition to the above, other conventional techniques for embedding a capacitor in a substrate include JP-A-6-326472, JP-A-7-263619, JP-A-11-45955, JP-A-11-126978, and JP-A-1 -31868 publication.
[0008]
Japanese Patent Application Laid-Open No. 6-326472 discloses an invention in which a capacitor is embedded in a resin substrate made of glass epoxy, and by embedding the capacitor in the substrate in this way, noise of the power source is reduced, and a chip is provided. It is described that there is no need for a space for mounting a capacitor, and that the effect of reducing the size of the substrate can be obtained.
[0009]
Japanese Patent Application Laid-Open No. 7-263619 discloses an invention in which a capacitor is embedded in a substrate made of ceramic, alumina, or the like, and this capacitor is connected between a power supply layer and a ground layer. Thus, it is described that the effect that the length of the wiring can be shortened and the inductance can be reduced is obtained.
[0010]
However, even in a substrate in which the capacitor described in these publications is embedded, for example, when a reliability test is repeated 1000 times in a heat cycle, the electrical characteristics are deteriorated, cracks are generated in the substrate or the interlayer resin insulation layer, the capacitor There has been a problem that peeling occurs between the substrate and the substrate or the interlayer resin insulation layer.
[0011]
As a result of intensive studies to solve the above problems, the present inventors have improved the wettability of the capacitor surface or formed a uniform coating layer on the capacitor surface, whereby As a result, it was found that the adhesiveness of the capacitor was improved and peeling between the capacitor and the adhesive was less likely to occur and cracks were not easily generated in the adhesive.
[0015]
In the multilayer printed wiring board of the present invention, an interlayer resin insulation layer and a conductor circuit are sequentially formed on a substrate in which a capacitor is built in or stored, and the capacitor, the conductor circuit, and the upper and lower conductor circuits are formed. Is a multilayer printed wiring board connected through via holes, and at least a part of the surface of the capacitor is subjected to at least one of plasma treatment, cleaning treatment and acid treatment, A coating layer is formed,The substrate is a substrate having a cavity,The coating layer formed on the surface of the capacitor isFormed on the substrateIt is characterized by being bonded to the inner wall surface of the cavity.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The capacitor according to the first aspect of the present invention is a capacitor housed or built in a multilayer printed wiring board, and at least a part of the surface thereof has a contact angle with water (hereinafter also simply referred to as a contact angle) of 7 to 45 ° C. It is characterized by being.
[0017]
According to the capacitor of the first aspect of the present invention, since the contact angle with respect to water on the surface is 7 to 45 °, when this capacitor is embedded in the cavity of the substrate of the multilayer printed wiring board via an adhesive, Adhesiveness with the adhesive is uniform and can be satisfactorily adhered, and peeling between the capacitor and the adhesive does not occur, and cracks do not occur in the adhesive. Therefore, the capacitor according to the first aspect of the present invention is suitable for use in a multilayer printed wiring board.
[0018]
In the capacitor according to the first aspect of the present invention, at least a part of the surface has a contact angle with water of 7 to 45 °.
When the contact angle is less than 7 °, it is practically difficult. On the other hand, when the contact angle exceeds 45 °, adhesion is caused at the interface between the capacitor and the adhesive when the capacitor is built in the multilayer printed wiring board. Agent floating or peeling may occur.
[0019]
Next, the shape of the capacitor of the first invention will be described with reference to the drawings. As a capacitor | condenser of 1st this invention, the capacitor | condenser etc. of the shape shown to Fig.1 (a)-(c) are mentioned, for example.
1A to 1C are cross-sectional views schematically showing an example of the capacitor of the first present invention.
[0020]
As shown in FIGS. 1A to 1C, the capacitors 20, 120, and 220 include a first electrode 21 and a second electrode 22, and a dielectric 23 sandwiched between the first electrode 21 and the second electrode 22. The dielectric 23 includes a plurality of first conductive films 24 connected to the first electrode 21 side and a plurality of second conductive films 25 connected to the second electrode 22 side.
[0021]
Furthermore, in the capacitor 20 shown in (a), a metal layer 26 made of Sn or the like is formed around the first electrode 21 and the second electrode 22.
Further, in the capacitor 120 shown in (b), a metal layer 126 is formed in a portion excluding the upper surfaces of the first electrode 21 and the second electrode 22.
Thus, by forming the metal layers 26 and 126, rust prevention, solderability, etc. can be improved.
The metal layer may not be formed at all as shown in (c), or may be formed only on any one of the upper surface, side surface, and lower surface of the electrode.
[0022]
The capacitor of the present invention is a capacitor having such a shape, and at least a part of the contact angle of the surface is kept at 7 to 45 °, so that the adhesiveness with the adhesive is excellent. Therefore, in consideration of the adhesiveness with the required adhesive, the capacitor may have a contact angle of at least a part of the capacitor surface within the above range, but the contact angle of the entire surface of the capacitor is within the above range. It is desirable to be.
[0023]
Examples of the method for adjusting the contact angle of the capacitor surface within the above range include a method of subjecting the capacitor surface to plasma treatment, cleaning treatment, acid treatment, and the like.
[0024]
Examples of the plasma treatment include a method using oxygen, nitrogen, carbon dioxide, carbon tetrachloride and the like.
Among these, it is desirable to use oxygen. This is because the capacitor is not damaged and can be processed at low cost.
[0025]
In addition, the plasma radiation amount in the plasma treatment is desirably 200 to 1000 W, and the treatment time is desirably 1 to 20 minutes under vacuum. If the treatment time is less than 1 minute, the contact angle may not be improved to the above range, whereas if it exceeds 20 minutes, the effect of improving the contact angle may be offset.
Moreover, it is desirable to perform the said process under pressure reduction.
[0026]
Examples of the cleaning treatment include alkali cleaning, acid cleaning, and neutral cleaning.
In the cleaning treatment, the contact angle on the capacitor surface can be set within the above range mainly by a degreasing action or a removing action of foreign matters such as an oxide film.
[0027]
The alkali cleaning is performed by, for example, spraying a solution in which a salt of caustic soda or alkaline silicic acid, carbonic acid, phosphoric acid, condensed phosphoric acid or the like is added to an anionic surfactant and a nonionic surfactant. It can be carried out by immersing the capacitor inside. Moreover, it can also carry out by the electrolytic cleaning method which added surfactant.
[0028]
The acid cleaning can be performed, for example, by spraying a solution obtained by adding a cationic surfactant to an acid such as sulfuric acid or hydrochloric acid, or immersing a capacitor in the solution.
[0029]
Examples of the acid treatment include a method of immersing in a solution containing at least one acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid.
In these, the process performed using a sulfuric acid and / or a hydrofluoric acid is desirable.
This is because the contact angle can be improved within the above range in a short time, and no residue remains on the capacitor surface after the treatment.
[0030]
In the acid treatment, the concentration of the acid in the solution is preferably 10% by weight or more.
This is because when the acid concentration is less than 10% by weight, it takes a long time to improve the contact angle to the above range, and as a result, the capacitor may be altered or deformed.
[0031]
Further, the immersion time in the acid solution may be appropriately selected in consideration of the type of acid to be used and its concentration, but it is usually preferably 1 to 15 minutes.
If the immersion time is less than 1 minute, the contact angle may not be improved to the above range, whereas if it exceeds 15 minutes, the effect of improving the contact angle may be offset. The immersion time in the acid solution is more preferably 2 to 10 minutes. This is because it is easy to make the contact angle more desirable and damage to the metal or the like is small.
Moreover, as for the liquid temperature of the solution which consists of the said acid, 20-40 degreeC is desirable.
This is because if the temperature exceeds 40 ° C., the capacitor may be altered or deformed.
[0032]
Such a processing method may be used independently and may be used combining several processing methods. Therefore, each of the electrode surface, the metal layer surface, and the dielectric surface may be treated by different methods.
By using such a method to form a rough surface on at least a part of the capacitor surface, a conventional surface mounting capacitor can be made suitable for being incorporated in a multilayer printed wiring board.
[0033]
In the present specification, the part of the capacitor surface means the entire surface of a part formed of the same material, and does not mean an arbitrary part of the capacitor surface. Therefore, for example, in the capacitor having the shape shown in FIG. 1, when the side surface of the metal layer 26 corresponds to a part of the capacitor surface referred to in this specification, the entire side surface of the metal layer 26 has a contact angle in the above range, A part of the side surface of the metal layer 26 does not have a contact angle in the above range.
[0034]
Next, the capacitor of the second invention will be described.
The capacitor of the second aspect of the present invention is a capacitor to be housed or built in a multilayer printed wiring board,
At least a part of the surface is characterized in that a coating layer is formed after at least one of plasma treatment, cleaning treatment and acid treatment is performed.
[0035]
According to the capacitor of the second aspect of the present invention, since the coating layer is formed on the surface and the surface is uniform, the capacitor is embedded in the cavity of the substrate of the multilayer printed wiring board via an adhesive. Is excellent in adhesiveness with the adhesive and does not cause separation between the capacitor and the adhesive or cracks in the adhesive. Therefore, the capacitor according to the second aspect of the present invention is also suitable for incorporation in a multilayer printed wiring board.
[0036]
In the capacitor according to the second aspect of the present invention, at least a part of the surface thereof is subjected to at least one of plasma treatment, cleaning treatment, and acid treatment, and then a coating layer is formed.
[0037]
As the plasma treatment, cleaning treatment, and acid treatment, methods similar to those treatment methods used for improving the contact angle of the surface of the first capacitor can be used.
Accordingly, in the capacitor of the second aspect of the present invention, foreign matters such as oil on the capacitor surface are removed.
[0038]
Furthermore, in the capacitor according to the second aspect of the present invention, a coating layer is formed after the above treatment.
The material of the coating layer is not particularly limited. However, since the capacitor is built in the multilayer printed wiring board via an adhesive, a material having excellent affinity with the adhesive to be used is desirable.
[0039]
Accordingly, the material of the coating layer may be appropriately selected in consideration of the material of the adhesive, and a resin is usually desirable.
Examples of the method for forming the coating layer include a method in which a vinyl monomer or the like is graft-polymerized on the surface of the dielectric, or an active group is generated on the surface of the dielectric by mechanical treatment such as ultrasonic treatment. Examples thereof include a method of reacting a group with a polymer, and a method of reacting the reactive group with vinyltrichlorosilane, vinyltriethoxysilane or the like when a reactive group such as a hydroxyl group is present on the dielectric surface.
Such a capacitor according to the second aspect of the present invention has a coating layer formed on at least a part of the surface of the capacitor according to the first aspect of the present invention. For example, the capacitor shown in FIGS. A coating layer is formed on at least a part of the surface.
[0040]
Next, the multilayer printed wiring board of the present invention will be described.
In the multilayer printed wiring board of the present invention, an interlayer resin insulating layer and a conductor circuit are sequentially formed on a substrate in which a capacitor is incorporated or accommodated, and the capacitor, the conductor circuit, and the upper and lower conductor circuits have via holes. A multilayer printed wiring board connected via
The capacitor is a capacitor according to the first or second aspect of the present invention.
[0041]
According to the multilayer printed wiring board of the present invention, since the capacitor of the first or second aspect of the present invention is built in the substrate, peeling occurs between the capacitor and the adhesive, or the adhesive has cracks. It does not occur. Therefore, the multilayer printed wiring board is excellent in electrical connectivity and reliability without disconnecting the connection between the capacitor terminal and the via hole or causing the interlayer resin insulation layer to swell.
[0042]
In this case, the resin around the capacitor expands and contracts due to heat cycle, etc., and stress is generated in the resin due to this expansion and contraction, but in the capacitor of the present invention, the resin is bonded to the capacitor with a uniform adhesive force as a whole. The stress does not concentrate on a part of the resin.
As a result, the peripheral resin does not crack or peel off from the capacitor, and the capacitor does not shift.
[0043]
The multilayer printed wiring board of the present invention will be described below with reference to the drawings.
First, a first embodiment of the multilayer printed wiring board will be described.
FIG. 2 is a cross-sectional view schematically showing an example of the multilayer printed wiring board of the present invention. FIG. 3 is a schematic view showing a state in which an IC chip is mounted on the multilayer printed wiring board shown in FIG. FIG.
[0044]
As shown in FIG. 2, the multilayer printed wiring board 10 is formed with a capacitor 20, a substrate 30 containing the capacitor 20, and interlayer resin insulation layers 40 and 60. A via hole 46 and a conductor circuit 48 are formed in the interlayer resin insulation layer 40, and a via hole 66 and a conductor circuit 68 are formed in the interlayer resin insulation layer 60. A through hole 36 is formed to connect the upper and lower conductor circuits via the substrate 30.
[0045]
Further, a solder resist layer 70 is disposed on the interlayer insulating layer 60, and a conductor circuit 68 (including the via hole 66) under the opening 71 of the solder resist layer 70 includes a daughter board, a mother board, and the like. Solder bumps 76 for connecting to an external substrate are provided via a nickel plating layer and a gold plating layer.
[0046]
In the multilayer printed wiring board 10, the capacitor 20 is built in the substrate via the adhesive 32, and the capacitor 20 is the capacitor of the first or second aspect of the present invention. For this reason, the adhesiveness between the capacitor 20 and the adhesive 32 is high, and even under heat cycle conditions, peeling occurs on the contact surface between the capacitor 20 and the adhesive 32 or cracks occur in the adhesive. There is no. Therefore, the connection between the capacitor terminal and the via hole is not cut off and the interlayer resin insulating layer is not swollen, and the multilayer printed wiring board 10 is excellent in electrical connectivity and reliability.
[0047]
It does not specifically limit as said adhesive agent, For example, an epoxy resin, a phenol resin, etc. are mentioned.
[0048]
Further, as shown in FIG. 3, in the multilayer printed wiring board on which the IC chip 90 is mounted and attached to the daughter board, the bumps 76 formed in the openings 71 of the upper solder resist layer 70 and the IC chip 90 Pads 92S1, 92S2, 92P1, and 92P2 are connected. The bumps 76 formed in the openings 71 of the lower solder resist layer 70 are connected to the pads 96S1, 96S2, 96P1, and 96P2 of the daughter board 94.
[0049]
Also, the signal pad 92S2 of the IC chip 90 shown in FIG. 3 is a signal pad of the daughter board 94 via the bump 76-conductor circuit 68-via hole 66-through hole 36-via hole 66-bump 76. It is connected to 96S2. On the other hand, the signal pad 92S1 of the IC chip 90 is connected to the signal pad 96S1 of the daughter board 94 via the bump 76-via hole 66-through hole 36-via hole 66-bump 76.
[0050]
The power supply pad 92P1 of the IC chip 90 is connected to the first electrode 21 of the chip capacitor 20 via the bump 76-via hole 66-conductor circuit 48-via hole 46. On the other hand, the power supply pad 96P1 of the daughter board 94 is connected to the first electrode 21 of the chip capacitor 20 via the bump 76-via hole 66-through hole 36-conductor circuit 48-via hole 46.
[0051]
The power supply pad 92P2 of the IC chip 90 is connected to the second electrode 22 of the chip capacitor 20 via the bump 76, the via hole 66, the conductor circuit 48, and the via hole 46. On the other hand, the power supply pad 96P2 of the daughter board 94 is connected to the second electrode 22 of the chip capacitor 20 via the bump 76-via hole 66-through hole 36-conductor circuit 48-via hole 46.
[0052]
Therefore, in the multilayer printed wiring board of the present invention, as shown in FIG. 15C, by incorporating the capacitor 20 in the substrate, the capacitor 20 is disposed directly under the IC chip 90, and the capacitor 20 is interposed. The distance between the power supply and the power supply terminal 92E / earth terminal 92P of the IC chip 90, that is, the loop length that determines the loop inductance is further shortened as shown by the solid line in FIG.
As a result, even when the IC chip 90 that is driven at a high frequency is mounted, the loop inductance is sufficiently low, and power can be instantaneously supplied to the IC chip side.
[0053]
Further, by providing the through hole 36 between the capacitors 20, the signal line can be prevented from passing through the capacitor. Therefore, it is possible to prevent reflection due to impedance discontinuity due to the high dielectric material that occurs when the signal line passes through the capacitor, and signal propagation delay due to passage through the high dielectric material.
[0054]
Next, a method for manufacturing the multilayer printed wiring board according to the first embodiment shown in FIG. 2 (first multilayer printed wiring board manufacturing method) will be described with reference to FIGS.
[0055]
(1) A resin film 40α having a metal film 41 laminated on one side is used as a starting material (see FIG. 4A). Examples of the resin film 40α include a thermosetting resin such as an epoxy resin, a bismaleimide / triazine (BT) resin, a polyimide resin, and an olefin resin, or a resin composite of a thermosetting resin and a thermoplastic resin. Is mentioned. A photosensitive resin can also be used.
[0056]
Specific examples of the polyolefin resin include polyethylene, polypropylene, polyisobutylene, polybutadiene, polyisoprene, cycloolefin resin, and copolymers of these resins.
As a commercial item of the said polyolefin resin, the Sumitomo 3M brand name: 1592 etc. are mentioned, for example. Moreover, as a commercial item of thermoplastic polyolefin-type resin whose melting | fusing point is 200 degreeC or more, the brand name: TPX (melting | fusing point 240 degreeC) made by Mitsui Petrochemical Industry Co., Ltd. Melting point of 270 ° C.).
[0057]
Of these, cycloolefin resins are desirable.
Cycloolefin resin has a low dielectric constant, and even when high-frequency signals in the GHz band are used, signal delays and signal errors are less likely to occur, and mechanical properties, particularly high rigidity, make it a solid interlayer resin insulator. As a result, the connection reliability of the multilayer printed wiring board can be sufficiently ensured.
[0058]
In addition, since the cycloolefin resin is excellent in adhesion to the conductor circuit, the interlayer resin insulation layer can be prevented from peeling from the conductor circuit, and cracks in the interlayer resin insulation layer due to the peeling can be prevented. Occurrence and the like can also be prevented.
Furthermore, since the cycloolefin resin has a low water absorption rate, the electrical insulation between the conductor circuits is increased and the reliability is improved.
[0059]
The cycloolefin-based resin is preferably a homopolymer or copolymer of a monomer composed of 2-norbornene, 5-ethylidene-2-norbornene, or a derivative thereof. Examples of the derivative include those in which an amino group for forming a bridge, a maleic anhydride residue, or a maleic acid-modified one is bonded to a cycloolefin such as 2-norbornene.
Examples of the monomer for synthesizing the copolymer include ethylene and propylene.
[0060]
The cycloolefin-based resin may be a mixture of two or more of the above-described resins, or may include a resin other than the cycloolefin-based resin.
Moreover, when the said cycloolefin resin is a copolymer, a block copolymer may be sufficient and a random copolymer may be sufficient.
[0061]
The cycloolefin resin is preferably a thermosetting cycloolefin resin. This is because by heating to form a crosslink, the rigidity becomes higher and the mechanical properties are improved.
The glass transition temperature (Tg) of the cycloolefin resin is preferably 130 to 200 ° C.
[0062]
The cycloolefin-based resin may not contain a filler or the like, or may contain a flame retardant such as aluminum hydroxide, magnesium hydroxide, or phosphate ester.
[0063]
The resin composite includes a thermoplastic resin and a thermosetting resin.
Examples of the thermoplastic resin include polysulfone (PSF), polyether sulfone (PES), polyphenylene sulfone (PPS), polyphenylene sulfide (PPES), polyphenylene ether (PPE), polyetherimide (PI), phenoxy resin, A fluororesin etc. are mentioned.
Of these, polysulfone (PSF), polyethersulfone (PES), polyetherimide (PI) and / or phenoxy resin are desirable. This is because it is excellent in heat resistance and insulation and has a high toughness value, and is therefore particularly suitable for forming an interlayer resin insulation layer having excellent crack resistance and shape retention.
[0064]
As said thermosetting resin, an epoxy resin, a phenol resin, a polyimide resin etc. are mentioned, for example. Further, the thermosetting resin may be a sensitized resin, and specific examples thereof include those obtained by acrylate reaction of methacrylic acid, acrylic acid, and the like with a thermosetting group. In particular, an acrylated epoxy resin is desirable. Among these, an epoxy resin having two or more epoxy groups in one molecule is more desirable.
[0065]
Examples of the epoxy resin include cresol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, alkylphenol novolac type epoxy resin, biphenol F type epoxy resin, naphthalene type epoxy resin, Examples thereof include cyclopentadiene type epoxy resins, epoxidized products of condensates of phenols and aromatic aldehydes having a phenolic hydroxyl group, triglycidyl isocyanurate, and alicyclic epoxy resins. These may be used alone or in combination of two or more. Thereby, it will be excellent in heat resistance.
[0066]
The mixing ratio of the thermoplastic resin and the thermosetting resin in the resin composite is preferably thermosetting resin / thermoplastic resin = 95/5 to 50/50. This is because a high toughness value can be ensured without impairing heat resistance.
[0067]
Specific examples of the resin composite include, for example, coarse particles in which particles soluble in an acid or an oxidizing agent (hereinafter referred to as soluble particles) are dispersed in a resin that is hardly soluble in an acid or oxidizing agent (hereinafter referred to as a poorly soluble resin). Examples thereof include a resin composition for forming a chemical surface.
As used herein, the terms “slightly soluble” and “soluble” refer to those having a relatively high dissolution rate as “soluble” for convenience when immersed in the same roughening solution for the same time. The slow one is called “slightly soluble” for convenience.
[0068]
Examples of the soluble particles include resin particles soluble in an acid or an oxidizing agent (hereinafter, soluble resin particles), inorganic particles soluble in an acid or an oxidizing agent (hereinafter, soluble inorganic particles), and a metal soluble in an acid or an oxidizing agent. Examples thereof include particles (hereinafter, soluble metal particles). These soluble particles may be used alone or in combination of two or more.
[0069]
The shape of the soluble particles is not particularly limited, and examples thereof include spherical shapes and crushed shapes. Moreover, it is desirable that the soluble particles have a uniform shape. This is because a roughened surface having unevenness with uniform roughness can be formed.
[0070]
The average particle size of the soluble particles is preferably 0.1 to 10 μm. If it is the range of this particle size, you may contain a 2 or more types of different particle size thing. That is, it contains soluble particles having an average particle size of 0.1 to 0.5 μm and soluble particles having an average particle size of 1 to 3 μm. Thereby, a more complicated roughened surface can be formed and it is excellent also in adhesiveness with a conductor circuit. In the present specification, the particle size of the soluble particles is the length of the longest part of the soluble particles.
[0071]
The soluble resin particle is not particularly limited as long as it has a higher dissolution rate than the hardly soluble resin when immersed in a solution comprising an acid or an oxidizing agent. Specific examples thereof include, for example, an epoxy resin, Examples include phenol resins, phenoxy resins, polyimide resins, polyphenylene resins, polyolefin resins, fluororesins, amino resins (melamine resins, urea resins, guanamine resins) and the like, and even those consisting of one of these resins. It may be a mixture of two or more resins.
[0072]
Moreover, as the soluble resin particles, resin particles made of rubber can be used. Examples of the rubber include polybutadiene rubber, epoxy-modified, urethane-modified, various modified polybutadiene rubbers such as (meth) acrylonitrile modification, (meth) acrylonitrile-butadiene rubber containing a carboxyl group, and the like. By using these rubbers, the soluble resin particles are easily dissolved in an acid or an oxidizing agent. That is, when soluble resin particles are dissolved using an acid, acids other than strong acids can be dissolved. When soluble resin particles are dissolved using an oxidizing agent, permanganese having a relatively low oxidizing power is used. Even acids can be dissolved. Even when chromic acid is used, it can be dissolved at a low concentration. Therefore, no acid or oxidant remains on the resin surface. As described later, when a catalyst such as palladium chloride is applied after the roughened surface is formed, the catalyst is not applied or the catalyst is oxidized. There is nothing to do.
[0073]
Examples of the soluble inorganic particles include particles composed of at least one selected from the group consisting of aluminum compounds, calcium compounds, potassium compounds, magnesium compounds, and silicon compounds.
[0074]
Examples of the aluminum compound include alumina and aluminum hydroxide. Examples of the calcium compound include calcium carbonate and calcium hydroxide. Examples of the potassium compound include potassium carbonate. Examples of the magnesium compound include magnesia, dolomite, and basic magnesium carbonate. Examples of the silicon compound include silica and zeolite. These may be used alone or in combination of two or more.
[0075]
Examples of the soluble metal particles include particles composed of at least one selected from the group consisting of copper, nickel, iron, zinc, lead, gold, silver, aluminum, magnesium, calcium, and silicon. Further, the surface layer of these soluble metal particles may be coated with a resin or the like in order to ensure insulation.
[0076]
When two or more kinds of the soluble particles are used in combination, the combination of the two kinds of soluble particles to be mixed is preferably a combination of resin particles and inorganic particles. Since both have low conductivity, insulation between the upper and lower conductor circuits can be ensured, and thermal expansion can be easily adjusted with the hardly soluble resin, and no cracks are generated in the interlayer resin insulation layer. This is because no peeling occurs between the resin insulating layer and the conductor circuit.
[0077]
The hardly soluble resin may be any resin that can maintain the shape of the roughened surface when the roughened surface is formed using an acid or an oxidizing agent in the interlayer resin insulating layer. The thermoplastic resin and the thermosetting resin may be used. Mixtures with functional resins can be used.
[0078]
When the roughened surface forming resin composition is used as the resin composite, the soluble particles are desirably dispersed almost uniformly in the hardly soluble resin. This is because a roughened surface having unevenness with uniform roughness can be formed, and adhesion with a conductor circuit including a via hole can be secured.
Moreover, you may use the film containing a soluble particle only in the surface layer part which forms a roughening surface. In this case, since the portions other than the surface layer portion of the film are not exposed to the acid or the oxidizing agent, the insulation between the conductor circuits through the interlayer resin insulation layer is reliably maintained.
[0079]
The mixing weight ratio of the soluble particles is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, based on the solid content of the hardly soluble resin.
When the mixing weight ratio of the soluble particles is less than 5% by weight, a roughened surface with sufficient roughness may not be formed. When the mixing weight ratio exceeds 50% by weight, the soluble particles are dissolved using an acid or an oxidizing agent. When the roughened surface is formed, it melts to the deep part of the interlayer resin insulation layer, and insulation between the upper and lower conductor circuits through the resin insulation layer cannot be secured, causing a short circuit. There is.
[0080]
The roughened surface-forming resin composition preferably contains a curing agent, other components, and the like in addition to the thermoplastic resin and the thermosetting resin.
Examples of the curing agent include imidazole curing agents, amine curing agents, guanidine curing agents, epoxy adducts of these curing agents, microcapsules of these curing agents, triphenylphosphine, and tetraphenylphosphorus. And organic phosphine compounds such as nium tetraphenylborate.
[0081]
As for content of the said hardening | curing agent, it is desirable that it is 0.05 to 10 weight% with respect to the resin composition for roughening surface formation. If it is less than 0.05% by weight, the resin composite is not sufficiently cured when the interlayer resin insulation layer is formed, and a roughened surface is formed on the surface of the interlayer resin insulation layer by using an acid or an oxidant. May increase the degree of penetration of the resin film, and the insulating properties of the interlayer resin insulation layer may be impaired. On the other hand, if it exceeds 10% by weight, an excessive curing agent component may change the composition of the resin, which may lead to a decrease in reliability.
[0082]
Examples of the other components include fillers such as inorganic compounds and resins that do not affect the formation of the roughened surface.
Examples of the inorganic compound include silica, alumina, and dolomite. Examples of the resin include polyimide resin, polyacrylic resin, polyamideimide resin, polyphenylene resin, melanin resin, and olefin resin. By containing these fillers, the thermal expansion coefficient is matched, heat resistance and chemical resistance are improved, and the performance of the multilayer printed wiring board can be further improved.
[0083]
Moreover, the said resin composition for roughening surface formation may contain the solvent. Examples of the solvent include ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and aromatic hydrocarbons such as ethyl acetate, butyl acetate, cellosolve acetate, toluene, and xylene. These may be used alone or in combination of two or more.
[0084]
(2) Next, the metal film 41 is pattern-etched to form a predetermined circuit pattern 42 (see FIG. 4B). Subsequently, the capacitor 20 that has been subjected to the above-described plasma treatment or the like is adhered to the circuit pattern 42 on the lower surface of the resin film 40α via an adhesive material 34 such as solder or conductive paste.
In this case, since the capacitor is connected to the circuit pattern 42 via an adhesive material such as solder, it is desirable that a metal layer made of Sn is formed around the first and second electrodes of the capacitor.
[0085]
(3) Separately from the resin film 40α, a substrate 30α having a cavity 31 in which the capacitor 20 is built is prepared.
The cavity 31 is formed by bonding, injection molding, or the like between a prepreg having a through hole and a through hole and a prepreg having no through hole.
The substrate 30α is not particularly limited as long as it is generally used for printed wiring boards. For example, a resin obtained by impregnating a reinforcing material such as a glass epoxy resin or a core material into an epoxy resin, a BT resin, a phenol resin, or the like. And a substrate laminated with a prepreg impregnated with an epoxy resin. Moreover, you may use a double-sided copper clad laminated board, a single-sided board, the resin board which does not have a metal film, a resin film, etc.
[0086]
(4) Next, the resin film 40α to which the capacitor 20 is attached, the substrate 30α having the cavity 31 and another resin film 40α are laminated and then pressed (FIGS. 4C and 4D). )), And then, if necessary, a cured layer 40β of the resin film is formed by heating and curing (see FIG. 5A). At this time, by applying an adhesive to the inner wall surface of the cavity 31 and / or the capacitor in advance, the capacitor is bonded to the inner wall surface of the cavity 31 via the adhesive 32.
[0087]
(5) Next, a via hole opening 43 is formed in the cured layer 40β of the resin film to form the interlayer resin insulating layer 40 (see FIG. 5B).
The via hole opening 43 is formed by laser processing. At this time, as a laser to be used, for example, carbon dioxide (CO₂ ) Laser, ultraviolet laser, excimer laser and the like. Among these, an excimer laser and a short pulse carbon dioxide laser are desirable.
[0088]
As will be described later, the excimer laser can form a large number of via hole openings at a time by using a mask or the like in which a through hole is formed in a portion where a via hole opening is formed. This is because the pulse carbon dioxide laser has little resin residue in the opening, and damage to the resin around the laser irradiation site is particularly small.
[0089]
Among excimer lasers, it is desirable to use a hologram type excimer laser. The hologram method is a method of irradiating a target object with laser light through a hologram, a condensing lens, a laser mask, a transfer lens, and the like. Can be formed efficiently.
[0090]
When a carbon dioxide laser is used, the pulse interval is 10^-Four-10^-8It is desirable to be seconds. In addition, the time for irradiating the laser for forming the opening is desirably 10 to 500 μm seconds.
Further, the through-hole of the mask in which the through-hole is formed in the portion forming the opening for the via hole needs to be a perfect circle in order to make the spot shape of the laser light a perfect circle, and the diameter of the through-hole is About 0.1 to 2 mm is desirable.
[0091]
In addition, by irradiating laser light through an optical system lens and a mask, a large number of openings for via holes can be formed at one time. This is because laser light having the same intensity and the same irradiation intensity can be irradiated to a plurality of portions through the optical system lens and the mask.
[0092]
When a photosensitive resin is used as the resin film 40α, a via hole opening may be formed by exposure / development processing.
In this case, it is desirable to perform exposure / development processing after laminating and pressing the resin film 40α and before heat curing.
This is because a completely cured layer is not suitable for forming an opening by exposure / development processing, and an opening having a desired shape cannot be formed.
[0093]
(6) Next, desmear processing is performed as necessary. The desmear treatment can be carried out using an oxidizing agent comprising an aqueous solution such as chromic acid or permanganate. Also oxygen plasma, CF_Four You may process by the mixed plasma of oxygen and oxygen, corona discharge, etc. Further, the surface can be modified by irradiating with ultraviolet rays using a low-pressure mercury lamp.
Thereafter, through-holes 33 for through holes are formed by drilling or laser processing. The diameter of the through hole 33 for the through hole is preferably 50 to 500 μm (see FIG. 5C).
[0094]
Further, after the through hole 33 for through hole is formed, a roughened surface may be formed on the surface of the interlayer resin insulating layer 40 (including the via hole opening and the inner wall surface of the through hole through hole).
For example, when the polyolefin resin is used as the material of the interlayer resin insulation layer 40, a roughened surface can be formed by plasma treatment, and when the roughened surface forming resin composition is used. The roughened surface can be formed using an acid or an oxidizing agent.
[0095]
(7) Next, the thin film conductor layer 44 is formed on the surface of the interlayer resin insulation layer 40 (including the via hole opening and the inner wall surface of the through hole through hole) by electroless plating, sputtering, or the like (FIG. 6A). reference). The thin film conductor layer 44 may be a single layer or may be composed of two or more layers.
In addition, when forming a thin film conductor layer by electroless plating, it is desirable to provide a catalyst nucleus such as a palladium catalyst on the surface of the interlayer resin insulation layer 40 in advance.
[0096]
Examples of the material of the thin film conductor layer 44 include tin, zinc, copper, nickel, cobalt, thallium, lead, and the like. Among these, those made of copper, copper and nickel are desirable from the viewpoint of excellent electrical characteristics, economical efficiency, and the like.
The thickness of the thin film conductor layer 44 is preferably 0.6 to 1.2 μm when the thin film conductor layer is formed by electroless plating, and 0.1 to 1.0 μm when formed by sputtering. desirable.
[0097]
(8) Next, a plating resist 51 is formed using a dry film on a part of the interlayer resin insulation layer 40 on which the thin film conductor layer 44 is formed, and then electrolytic plating is performed using the thin film conductor layer 44 as a plating lead. An electrolytic plating layer 45 is deposited on the plating resist non-forming portion (see FIG. 6B).
As the electrolytic plating, copper plating is desirable.
At this time, the via hole opening may be filled with electrolytic plating to form a field via structure. After filling the via hole opening with a conductive paste, a lid plating layer is formed thereon to form a field via structure. Also good. By forming the field via structure, a via hole can be provided immediately above the via hole.
[0098]
(9) Next, after removing the plating resist 51, the thin film conductor layer 44 existing under the plating resist 51 is dissolved and removed by etching, and a conductor circuit 48 comprising the thin film conductor layer 44 and the electrolytic plating layer 45, A via hole 46 and a through hole 36 are formed (see FIG. 6C).
When the thin film conductor layer 44 is formed by electroless plating after depositing the catalyst, the catalyst on the interlayer resin insulating layer 40 may be removed using an acid or an oxidizing agent. By removing the catalyst, it is possible to prevent a reduction in electrical characteristics.
[0099]
(10) Next, a roughened surface is formed on the surfaces of the conductor circuit 48, the via hole 46, and the through hole 36 as necessary. The roughened surface can be formed by etching, blackening reduction, plating, or the like.
[0100]
The said etching process can be performed using the etching liquid containing an organic acid and a cupric complex, for example.
Examples of the organic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, acrylic acid, crotonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, maleic acid, benzoic acid, glycolic acid, Examples include lactic acid, malic acid and sulfamic acid.
These may be used alone or in combination of two or more. In the mixed solution, the content of the organic acid is preferably 0.1 to 30% by weight. This is because the solubility of oxidized copper can be maintained and catalyst stability can be ensured.
[0101]
The cupric complex is preferably an azole cupric complex. This cupric complex of azoles acts as an oxidizing agent that oxidizes metallic copper and the like. Examples of azoles include diazole, triazole, tetrazole and the like. Among these, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 2-undecylimidazole are desirable. In the etching solution, the content of the cupric complex is preferably 1 to 15% by weight. This is because it is excellent in solubility and stability and can also dissolve noble metals such as Pd constituting the catalyst nucleus.
[0102]
Specific methods of the blackening reduction treatment include NaOH (10 g / l), NaClO.₂ (40 g / l), Na_Three PO_Four A blackening treatment using an aqueous solution containing (6 g / l), and NaOH (10 g / l), NaBH_Four And a method of performing a reduction treatment using an aqueous solution containing (6 g / l) as a reduction bath.
[0103]
Specific methods of the plating treatment include copper sulfate (1-40 g / l), nickel sulfate (0.1-6.0 g / l), citric acid (10-20 g / l), sodium hypophosphite. (= 10-100 g / l), boric acid (10-40 g / l) and surfactant (manufactured by Nissin Chemical Industry Co., Surfinol 465) (0.01-10 g / l), electroless at pH = 9 The method etc. which perform electroless plating with a plating bath are mentioned.
[0104]
(11) Next, the inside of the through hole 36 is filled with a resin filler, and then a resin film 60α is pasted on both surfaces of the substrate 30 on which the conductor circuit 48 is formed (see FIG. 7A).
As the resin filler, there can be used a non-conductive resin whose main component is a resin such as an epoxy resin, a conductive resin containing a metal paste such as copper, and the like. Moreover, you may use the resin filler which mix | blended inorganic fillers, such as a silica, with the thermosetting epoxy resin, and matched the thermal expansion coefficient with the interlayer resin insulation layer.
Moreover, as the resin film 60α, the same resin film 40α can be used.
[0105]
(12) Next, if necessary, after curing the resin film, the above steps (5) to (10) (excluding the through hole forming step) are repeated to further increase the interlayer A resin insulating layer 60 and a conductor circuit 66 (via hole 68) are formed (see FIGS. 7B to 8B).
[0106]
(13) Next, a solder resist layer 70 having an opening 71 is formed on the substrate surface including the outermost conductor circuit 68. As said soldering resist layer, what consists of a polyphenylene ether resin, polyolefin resin, a fluorine resin, a thermoplastic elastomer, a soldering resist resin composition etc. is mentioned, for example.
The solder resist layer is coated with an uncured resin (resin composition) by a roll coater method, or after thermocompression bonding of an uncured resin film, followed by laser processing, exposure / development processing, etc. It is formed by performing a curing process or the like.
[0107]
Examples of the solder resist resin composition include (meth) acrylates of novolak-type epoxy resins, imidazole curing agents, bifunctional (meth) acrylate monomers, and heavy (meth) acrylate esters having a molecular weight of about 500 to 5,000. Examples include thermosetting resins composed of coalesced bisphenol-type epoxy resins, photosensitive monomers such as polyvalent acrylic monomers, paste-like fluids containing glycol ether solvents, and the like. It is desirable that the pressure is adjusted to 10 Pa · s.
[0108]
Examples of the (meth) acrylate of the novolak type epoxy resin include an epoxy resin obtained by reacting a glycidyl ether of phenol novolak or cresol novolak with acrylic acid or methacrylic acid.
Moreover, it does not specifically limit as said bifunctional (meth) acrylic acid ester monomer, For example, various diols, ester of acrylic acid, methacrylic acid, etc. are mentioned.
The opening 71 is formed by exposure / development processing, laser processing, or the like.
[0109]
(14) Thereafter, by forming a nickel plating layer 72, a gold plating layer 74, etc. on the conductor circuit 68 in the opening 71 of the solder resist layer 70, a solder pad is provided, and a solder paste is provided on the solder pad. Is printed and reflowed at 200 ° C. to form solder bumps 76. As a result, a multilayer printed wiring board having the IC chip 20 built in the substrate and having solder bumps can be obtained (see FIG. 2).
In addition, after printing solder paste on the opening of the solder resist layer, a conductive pin is placed on the opening and reflowed at 200 ° C., thereby connecting to an external terminal (PGA (Pin Grid Array)). It is good also as a multilayer printed wiring board by which is arranged.
[0110]
Next, a multilayer printed wiring board according to a second embodiment will be described with reference to FIG.
FIG. 9 is a sectional view schematically showing an example of the multilayer printed wiring board of the present invention.
The multilayer printed wiring board 110 of the second embodiment shown in FIG. 9 is substantially the same as the multilayer printed wiring board of the first embodiment.
However, the multilayer printed wiring board 110 differs in the method of incorporating the capacitor.
That is, in the first embodiment, the first electrode 21 and the second electrode 22 of the capacitor and the via hole 46 are electrically connected using an adhesive material 34 such as solder or conductive paste. In the multilayer printed wiring board of the second embodiment, the first electrode 21 and the second electrode 22 are plated to electrically connect the via hole. Therefore, capacitors suitable for each built-in method are used.
[0111]
Therefore, the capacitors used in the first and second embodiments will be described.
In the capacitor 20 used in the first embodiment, as shown in FIG. 1A, a metal layer 26 made of Sn or the like is formed on the outer periphery of the first electrode 21 and the second electrode 22. This is because when the metal layer 26 made of Sn or the like is provided, solderability is improved and a rust prevention effect is provided. Therefore, when the capacitor of the second aspect of the present invention is used, it is desirable that no coating layer is formed on the soldered portion.
[0112]
On the other hand, as shown in FIG. 1B, the capacitor 120 used in the second embodiment is formed with a metal layer 126 so that the upper surfaces of the first electrode 21 and the second electrode 22 are exposed. Therefore, it is suitable for connecting an electrode and a via hole using plating. When the capacitor of the second aspect of the present invention is used, it is desirable that a coating layer is not formed on the exposed electrode portion.
In addition, when an electrode and a via hole are connected by plating, the connection resistance can be reduced.
[0113]
Next, a method for manufacturing the multilayer printed wiring board shown in FIG. 9 (second multilayer printed wiring board manufacturing method) will be described with reference to FIGS.
[0114]
(1) A through hole for incorporating a capacitor is formed in a bismaleimide / triazine resin (BT resin) plate 35, and a laminated plate 30α in which four of these are laminated and two BT resin plates 35 in which no through hole is formed are laminated. The laminated plate 30β thus obtained is used as a starting material (see FIG. 10A).
As the laminated plates 30α and 30β, in addition to the laminated plate made of the BT resin, for example, those made of an epoxy resin or a phenol resin, or those containing a reinforcing material such as a glass cloth can be used.
[0115]
(2) Next, the capacitor 120 subjected to the above-described plasma treatment or the like is built in the through hole 37 formed in the laminated plate 30α. The capacitor 120 is attached in the through hole 37 via the adhesive 32. Then, after laminating the laminated plate 30α and the laminated plate 30β, the substrate 30 with a built-in capacitor is obtained by pressure bonding (see FIG. 10B).
As said adhesive agent, the thing similar to the adhesive agent used with the manufacturing method of the 1st multilayer printed wiring board can be used.
[0116]
(3) Next, after laminating the resin film 40α on both surfaces of the capacitor-embedded substrate 30, pressure bonding is performed, and then, if necessary, the cured layer 40β of the resin film is formed by heat curing (FIG. 10 ( c) and (d)).
The resin film 40α is the same as that used in the first multilayer printed wiring board manufacturing method, that is, a thermosetting resin such as an epoxy resin, a BT resin, a polyimide resin, an olefin resin, or a thermosetting resin. A mixture with a thermoplastic resin or the like can be used.
[0117]
(4) Next, through-hole openings 33 are formed by drilling or laser processing (see FIG. 11A). The diameter of the through-hole opening 33 is preferably 50 to 500 μm.
Next, via hole openings 43 are formed in the cured layer 40β of the resin film formed on both surfaces of the substrate to form the interlayer resin insulating layer 40 (see FIG. 5B).
The via hole opening 43 is formed by laser processing. At this time, as the laser to be used, a laser similar to the method for manufacturing the first multilayer printed wiring board can be used.
When a photosensitive resin is used as the resin film 40α, a via hole opening may be formed by exposure / development processing.
[0118]
(5) Next, desmear processing is performed as necessary. In particular, when a via hole opening is formed using a carbon dioxide laser, it is desirable to perform a desmear process.
The desmear process can be performed by a method similar to the method for manufacturing the first multilayer printed wiring board.
Further, after completion of the desmear process, a roughened surface may be formed on the surface of the interlayer resin insulating layer 40 (including the inner wall surfaces of the via hole opening 43 and the through hole through hole 33) as necessary.
[0119]
(6) Next, the thin film conductor layer 44 is formed on the surface of the interlayer resin insulating layer 40 (including the inner wall surfaces of the via hole opening 43 and the through hole through hole 33) by electroless plating, sputtering, or the like (FIG. 11 ( c)). The thin film conductor layer 44 may be a single layer or may be composed of two or more layers.
In addition, when forming a thin film conductor layer by electroless plating, it is desirable to provide a catalyst nucleus such as a palladium catalyst on the surface of the interlayer resin insulation layer 40 in advance.
The material and thickness of the thin film conductor layer 44 are preferably the same as those in the first multilayer printed wiring board manufacturing method.
[0120]
(7) Next, a plating resist 51 is formed on a part of the interlayer resin insulation layer 40 on which the thin film conductor layer 44 is formed using a dry film (see FIG. 12A), and then the thin film conductor layer 44 is formed. Electrolytic plating is performed as a plating lead, and an electrolytic plating layer 45 is deposited on the plating resist non-forming portion (see FIG. 12B).
The formation of the plating resist 51 and the deposition of the electrolytic plating layer 45 can be performed by a method similar to the method for manufacturing the first multilayer printed wiring board.
[0121]
(8) Next, after removing the plating resist 51, the thin film conductor layer 44 existing under the plating resist 51 is dissolved and removed by etching, and a conductor circuit 48 comprising the thin film conductor layer 44 and the electrolytic plating layer 45, Via holes 46 and through holes 36 are formed (see FIG. 12C).
When the thin film conductor layer 44 is formed by electroless plating after depositing the catalyst, the catalyst on the interlayer resin insulating layer 40 may be removed using an acid or an oxidizing agent. By removing palladium used as the catalyst, it is possible to prevent a reduction in electrical characteristics.
[0122]
After this, although not shown, the method is similar to the method shown in FIGS. 7A to 8C.
(9) Next, roughened surfaces are formed on the surfaces of the conductor circuit 48, the via hole 46, and the through hole 36 as necessary. The roughened surface can be formed by etching treatment, blackening reduction treatment, plating treatment, or the like, as in the first manufacturing method.
[0123]
(10) Next, the inside of the through hole 36 is filled with a resin filler.
As said resin filler, the thing similar to the manufacturing method of a 1st multilayer printed wiring board can be used.
[0124]
(11) Next, if necessary, by repeating the steps (3) to (10) (excluding the through-hole forming step), the upper interlayer resin insulation layer 60 and the conductor circuit 68 ( Via hole 66).
[0125]
(12) Further, in the same manner as in the first multilayer printed wiring board manufacturing method (13) and (14), a solder resist layer and a solder bump are formed to obtain a multilayer printed wiring board with a built-in capacitor. (See FIG. 9).
[0126]
Next, a multilayer printed wiring board according to a third embodiment will be described with reference to FIG.
FIG. 13 is a cross-sectional view schematically showing an example of the multilayer printed wiring board of the present invention.
The multilayer printed wiring board 210 of the third embodiment shown in FIG. 13 is substantially the same as the multilayer printed wiring board of the second embodiment.
However, the multilayer printed wiring board 210 differs in the method of incorporating a capacitor. That is, in the second embodiment, only the IC chip side (upper side) of the first electrode 21 and the second electrode 22 is electrically connected, but in the present embodiment, the first electrode 21 and the second electrode 22 are connected. The IC chip side (upper side) and the daughter board side (lower side) are both electrically connected. Therefore, the external electrode of the capacitor has a so-called through-hole function, and the package structure can be simplified, so that it can be applied to a high-frequency IC chip.
[0127]
Next, a method for manufacturing the multilayer printed wiring board shown in FIG. 13 (third method for manufacturing a multilayer printed wiring board) will be described with reference to FIG.
(1) First, a through hole 37 in which a capacitor is built is formed in a laminate 30α formed by laminating bismaleimide / triazine resin (BT resin) plates (see FIG. 14A).
As the laminated plate 30α, in addition to the laminated plate made of the BT resin, for example, one made of an epoxy resin or a phenol resin, or one containing a reinforcing material such as glass cloth can be used.
[0128]
Next, the capacitor 220 subjected to the above-described plasma processing or the like is built in the through hole 37 in the laminated plate 30α (see FIG. 14B). An adhesive is applied in advance to the inner wall surface of the through hole 37, and the capacitor 220 is bonded to the inner wall surface of the through hole 37 via the adhesive.
[0129]
(2) The resin film 40α, the laminated plate 30α containing the capacitor 220, and the resin film 40α are laminated, pressure-bonded, and then heated and cured to cure the substrate 30 and the resin film 40β containing the capacitor 220. (See FIGS. 14C and 14D).
(3) Thereafter, in the same manner as in steps (4) to (12) of the second manufacturing method, an interlayer resin insulation layer and a conductor circuit are sequentially formed on both surfaces of the capacitor-embedded substrate 130, and further, solder is formed on the outermost layer. A multilayer printed wiring board with a built-in capacitor is manufactured by forming a resist layer (see FIG. 13).
[0130]
In addition, embodiments of the multilayer printed wiring board of the present invention are not limited to the first to third embodiments described above, and may be, for example, a form in which a large number of capacitors are incorporated in parallel in one cavity. In the multilayer printed wiring board of such an embodiment, the shortage of the power supply voltage can be compensated, and the malfunction of the IC can be eliminated. Therefore, such a multilayer printed wiring board is optimal for flip chip use.
[0131]
In such a multilayer printed wiring board, since the capacitor is built in the substrate, when the IC chip is mounted, the distance between the IC chip and the capacitor is short, and even when the IC chip driven at a high frequency is mounted. The loop inductance is sufficiently low. Further, the capacitor built in the substrate is the capacitor according to the first or second aspect of the present invention, and since the above-described plasma treatment or the like is performed, the adhesiveness between the capacitor and the adhesive is high, and under heat cycle conditions. However, peeling does not occur on the contact surface between the capacitor and the adhesive, and cracks do not occur in the adhesive. Therefore, the connection between the capacitor terminal and the via hole is not cut off, and the interlayer resin insulating layer is not swollen, and the electrical connectivity and reliability are excellent.
[0132]
【Example】
Hereinafter, the present invention will be described in more detail.
[0133]
Example 1
(1) An epoxy resin film 40α in which a metal film 41 made of copper is laminated on one side is used as a starting material (see FIG. 4A).
First, a predetermined circuit pattern 42 was formed by pattern-etching the metal film 41 (see FIG. 4B).
[0134]
(2) Next, the capacitor 20 was attached to the circuit pattern 42 formed on the resin film 40α via the solder 34 (see FIG. 4C).
As the capacitor 20, a capacitor obtained by subjecting the surface of a commercially available chip capacitor (Murata Manufacturing Co., Ltd., GPM33) to plasma treatment under the following conditions was used. The contact angle of the capacitor surface before the plasma treatment is 52 ° on the surface of the metal layer 26 and the surface of the dielectric 23 is 59 °. The contact angle after the plasma treatment is 10 ° on the surface of the metal layer 26 and the dielectric 23. The surface was 15 ° (see FIG. 1 (a)).
[0135]
As the plasma treatment, a plasma cleaning apparatus (manufactured by Matsushita Electric Industrial Co., Ltd., PC12F-G type) was used, under vacuum (0.01 Pa), plasma irradiation amount 800 W, oxygen supply amount 300 sec. / M, oxygen supply pressure 0.15 MPa, treatment time 5 minutes.
[0136]
Further, the measurement of the contact angle on the capacitor surface was performed using Elma Contact Angle Measurement Model 360 (manufactured by Elma Sales Co., Ltd.). In addition, the measurement was performed 3 times and the average value of 3 times was made into the contact angle.
[0137]
(3) Separately from the above, a substrate 30α having a cavity 31 for containing the capacitor 20 is prepared.
Next, after applying an adhesive to the inner wall of the cavity 31, the resin film 40α to which the capacitor 20 is attached, the substrate 30α having the cavity 31 formed therein, and another resin film 40α are stacked and pressed ( (Refer FIG.4 (c) and (d)).
An epoxy resin was used as the adhesive.
[0138]
(4) Next, a heat curing process was performed to form a substrate 30 containing the capacitor 20 and a cured layer 40β of a resin film (see FIG. 5A).
Subsequently, CO 2 having a wavelength of 10.4 μm is passed through a mask having a through-hole formed on the cured layer 40β of the resin film.₂ For via holes with a diameter of 60 μm on the resin film cured layer 40β under the conditions of a gas laser with a beam diameter of 4.0 mm, a dopp-hat mode, a pulse width of 8.0 μs, a mask through-hole diameter of 1.0 mm, and two shots. An opening 43 was formed to form an interlayer resin insulating layer 40 (see FIG. 5B). Thereafter, desmear treatment was performed using oxygen plasma.
[0139]
(5) Next, a through hole 33 having a diameter of 300 μm was formed by drilling in the substrate 30 on which the interlayer resin insulating layer 50 was formed (see FIG. 5C).
Further, a palladium catalyst (manufactured by Atotech) is applied to the surface of the interlayer resin insulation layer 40 (including the inner wall surfaces of the via hole opening 43 and the through-hole through hole 33), thereby the surface of the interlayer resin insulation layer 40. The catalyst nuclei were attached to.
[0140]
(6) Next, the substrate is immersed in an electroless copper plating aqueous solution having the following composition, and a thin film having a thickness of 0.6 to 0.9 μm is formed on the entire surface of the interlayer resin insulating layer 40 and the through hole 33 for the through hole. A conductor layer (electroless copper plating layer) 44 was formed (see FIG. 6A).
[Electroless plating aqueous solution]
NiSO_Four               0.003 mol / l
Tartaric acid 0.200 mol / l
Copper sulfate 0.030 mol / l
HCHO 0.050 mol / l
NaOH 0.100 mol / l
α, α'-bipyridyl 40 mg / l
Polyethylene glycol (PEG) 0.10 g / l
[Electroless plating conditions]
40 minutes at 35 ° C liquid temperature
[0141]
(7) Next, a commercially available photosensitive dry film is attached to the electroless copper plating 44, and a mask is placed thereon, and 100 mJ / cm.² Then, a plating resist 51 was provided by developing with 0.8% sodium carbonate aqueous solution.
Further, the substrate is washed and degreased with water at 50 ° C., washed with water at 25 ° C., washed with sulfuric acid, and then subjected to electrolytic copper plating under the following conditions. 45 was formed (see FIG. 6B).
[0142]
(Electrolytic plating aqueous solution)
Sulfuric acid 2.24 mol / l
Copper sulfate 0.26 mol / l
Additive 1.95 ml / l
(Manufactured by Atotech Japan, Kaparaside GL)
[Electrolytic plating conditions]
Current density 1 A / dm²
65 minutes
Temperature 22 ± 2 ° C
[0143]
(8) Next, after removing the plating resist 51 with 5% KOH, the electroless plating layer 44 under the plating resist 51 is removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide, and the interlayer resin insulation is removed. Conductor circuits 48 and via holes 46 were formed in the layer 40, and through holes 36 were formed in the substrate 30 (see FIG. 6C).
[0144]
(9) Next, the surfaces of the conductor circuit 48, the via hole 46, and the through hole 36 are etched using an etchant composed of an organic acid salt and a cupric complex, thereby roughening the surface. (Not shown) was formed.
Further, the substrate on which the conductor circuit 48 and the like are formed is immersed in a 70 ° C. solution containing 800 g / l of chromic acid for 3 minutes, and the surface of the interlayer resin insulation layer 40 between the conductor circuits located in the conductor circuit non-formation portion. Was etched by 1 μm to remove the palladium catalyst remaining on the surface.
[0145]
Furthermore, the resin filler layer 38 was formed by filling the through hole 36 with a resin filler using a squeegee and drying at 100 ° C. for 20 minutes.
The resin filler is 100 parts by weight of a bisphenol F-type epoxy monomer (manufactured by Yuka Shell Co., Ltd., molecular weight: 310, YL983U), the average particle diameter coated with a silane coupling agent is 1.6 μm, and the maximum SiO whose particle size is 15 μm or less₂ 170 parts by weight of spherical particles (manufactured by Adtech, CRS 1101-CE) and 1.5 parts by weight of a leveling agent (Perenol S4, manufactured by San Nopco) are placed in a container and mixed by stirring. What was prepared to 49 Pa.s was used. Here, 6.5 parts by weight of an imidazole curing agent (manufactured by Shikoku Kasei Co., Ltd., 2E4MZ-CN) was used as the curing agent.
[0146]
Thereafter, the resin film 60α was attached to both surfaces of the substrate (see FIG. 7A). A resin film made of an epoxy resin was used as the resin film 60α.
[0147]
(10) By repeating the steps (4) to (8) (excluding the through hole forming step), an upper conductor circuit 68 (including the via hole 66) is formed, and then the conductor By etching the surface of the circuit 66 to form a roughened surface (not shown), a multilayer wiring board having a conductor circuit formed on the outermost layer was obtained (FIG. 7B to FIG. 8). b)).
[0148]
(11) Next, a photosensitizing agent obtained by acrylating 50% of an epoxy group of a cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.) dissolved in diethylene glycol dimethyl ether (DMDG) to a concentration of 60% by weight. 46.67 parts by weight of oligomer (molecular weight 4000), 80 parts by weight of bisphenol A type epoxy resin dissolved in methyl ethyl ketone (manufactured by Yuka Shell, trade name: Epicoat 1001), 15 parts by weight of imidazole curing agent (manufactured by Shikoku Kasei Co., Ltd.) , Trade name: 2E4MZ-CN) 1.6 parts by weight, polyfunctional acrylic monomer (manufactured by Kyoei Chemical Co., Ltd., trade name: R604) which is a photosensitive monomer, polyvalent acrylic monomer (manufactured by Kyoei Chemical Co., Ltd., product) Name: DPE6A) 1.5 parts by weight, dispersion antifoaming agent (manufactured by San Nopco, trade name: S-65) 0.7 A weight part is put into a container, and a mixed composition is prepared by stirring and mixing. 2.0 parts by weight of benzophenone (manufactured by Kanto Chemical Co., Inc.) as a photoweight initiator and Michler's ketone as a photosensitizer for the mixed composition. (Kanto Chemical Co., Ltd.) 0.2 parts by weight was added to obtain a solder resist composition having a viscosity adjusted to 2.0 Pa · s at 25 ° C.
Viscosity measurement was performed using a B-type viscometer (DVL-B type, manufactured by Tokyo Keiki Co., Ltd.). In the case of 4 or 6 rpm, the rotor No. 3 according.
[0149]
(12) Next, the above-mentioned solder resist composition is applied to a multilayer wiring board in a thickness of 20 μm and dried at 70 ° C. for 20 minutes and at 70 ° C. for 30 minutes. A photomask having a thickness of 5 mm on which the pattern of the portion is drawn is brought into close contact with the solder resist layer 70 to 1000 mJ / cm² Were exposed to UV light and developed with DMTG solution to form openings 71 having a diameter of 200 μm (see FIG. 8C).
[0150]
(13) Next, the substrate on which the solder resist layer 70 is formed is nickel chloride (2.3 × 10^-1mol / l), sodium hypophosphite (2.8 × 10^-1mol / l), sodium citrate (1.6 × 10^-1A nickel plating layer (not shown) having a thickness of 5 μm was formed in the opening 71 by immersing in an electroless nickel plating solution containing 0.5 mol / l) of pH = 4.5. Further, the substrate was made of potassium gold cyanide (7.6 × 10 6^-3mol / l), ammonium chloride (1.9 × 10^-1mol / l), sodium citrate (1.2 × 10^-1mol / l), sodium hypophosphite (1.7 × 10^-1mol / l) is immersed in an electroless plating solution at 80 ° C. for 7.5 minutes to form a gold plating layer (not shown) having a thickness of 0.03 μm on the nickel plating layer. Solder pads were formed on the circuit 68 and the like.
[0151]
(14) Thereafter, solder bumps 76 were formed by printing solder paste in the openings 71 of the solder resist layer 70 and reflowing at 200 ° C. As a result, the multilayer printed wiring board 10 including the capacitor 20 and having the solder bumps 76 was obtained (see FIG. 2).
[0152]
(Example 2)
(1) Four prepregs 35 impregnated with epoxy resin are laminated, and a laminate 30α having a through hole for incorporating a capacitor and a laminate 30β having two prepregs 35 laminated are used as starting materials ( FIG. 10 (a)).
[0153]
(2) Next, the capacitor 120 is attached to the through hole formed in the laminated plate 30α with an adhesive (thermosetting resin) interposed therebetween, and the laminated plate 30α and the laminated plate 30β are laminated and pasted. As a result, a substrate 30 with a built-in was obtained (see FIG. 10B). Note that the adhesive was also interposed between the bottom surface of the capacitor 120 and the laminated plate 30β.
[0154]
As the capacitor 120, a commercially available chip capacitor (Murata Manufacturing Co., Ltd., GPM33) was used which was subjected to acid treatment by immersing it in a sulfuric acid solution having a concentration of 15 wt% and a temperature of 25 ° C. for 5 minutes. The contact angle of the capacitor surface before the acid treatment is 57 ° on the surface of the metal layer 26 and the surface of the dielectric 23 is 52 °. The contact angle after the acid treatment is 11 ° on the surface of the metal layer 26 and the dielectric 23 surface was 14 degrees (refer to Drawing 1 (b)).
[0155]
(3) Next, the resin film 40α is laminated and pressed on the upper and lower sides of the substrate 30 containing the capacitor 120, and then heat-cured, and the cured layer 40β of the resin film is formed on both surfaces of the substrate containing the capacitor 120. Formed (see FIGS. 10C and 10D).
As the resin film 40α, a resin film made of a thermosetting cycloolefin resin was used.
[0156]
(4) Next, a through hole 33 having a diameter of 300 μm was formed by drilling in the substrate 30 on which the cured layer 40β of the resin film was formed (see FIG. 11A).
[0157]
Subsequently, CO 2 having a wavelength of 10.4 μm is passed through a mask having a through-hole formed on the cured layer 40β of the resin film.₂ For via holes with a diameter of 60 μm on the resin film cured layer 40β under the conditions of a gas laser with a beam diameter of 4.0 mm, a dopp-hat mode, a pulse width of 8.0 μs, a mask through-hole diameter of 1.0 mm, and two shots. An opening 43 was formed to form an interlayer resin insulation layer 40 (see FIG. 11B). Thereafter, desmear treatment was performed using oxygen plasma.
[0158]
(5) Next, plasma treatment was performed using SV-4540 manufactured by Nippon Vacuum Technology Co., Ltd., and a roughened surface (not shown) was formed on the surface of the interlayer resin insulation layer 40. At this time, argon gas was used as the inert gas, and plasma treatment was performed for 2 minutes under the conditions of power 200 W, gas pressure 0.6 Pa, and temperature 70 ° C.
[0159]
(6) Next, using the same apparatus and using the internal argon gas, sputtering with a Ni—Cu alloy as a target was performed under conditions of atmospheric pressure 0.6 Pa, temperature 80 ° C., power 200 W, and time 5 minutes, A thin film conductor layer 44 made of a Ni—Cu alloy and having a thickness of 0.2 μm was formed on the surface of the interlayer resin insulation layer 40 and the through hole 33 (see FIG. 11C).
[0160]
(7) Next, a commercially available photosensitive dry film is attached to the electroless copper plating 44, and a mask is placed thereon, and 100 mJ / cm.² Then, a plating resist 51 was provided by developing with a 0.8% sodium carbonate aqueous solution (see FIG. 12A).
Further, the substrate is washed and degreased with water at 50 ° C., washed with water at 25 ° C., washed with sulfuric acid, and then subjected to electrolytic copper plating under the following conditions. 45 was formed (see FIG. 12B).
[0161]
(Electrolytic plating aqueous solution)
Sulfuric acid 2.24 mol / l
Copper sulfate 0.26 mol / l
Additive 1.95 ml / l
(Manufactured by Atotech Japan, Kaparaside GL)
[Electrolytic plating conditions]
Current density 1 A / dm²
65 minutes
Temperature 22 ± 2 ° C
[0162]
(8) Next, after removing the plating resist 51 with 5% KOH, the electroless plating layer 44 under the plating resist 51 is removed by etching with a mixed solution of sulfuric acid and hydrogen peroxide, and the interlayer resin insulation is removed. Conductor circuits 48 and via holes 46 were formed in the layer 40, and through holes 36 were formed in the substrate 30 (see FIG. 12C).
[0163]
(9) Next, the surfaces of the conductor circuit 48, the via hole 46, and the through hole 36 are etched using an etchant composed of an organic acid salt and a cupric complex, thereby roughening the surface. (Not shown) was formed.
Further, the substrate on which the conductor circuit 48 and the like are formed is immersed in a 70 ° C. solution containing 800 g / l of chromic acid for 3 minutes, and the surface of the interlayer resin insulation layer 40 between the conductor circuits located in the conductor circuit non-formation portion. Was etched by 1 μm to remove the palladium catalyst remaining on the surface.
[0164]
Furthermore, the resin filler layer 38 was formed by filling the through hole 36 with a resin filler using a squeegee and drying at 100 ° C. for 20 minutes.
In addition, as a resin filler, the thing similar to the resin filler used in Example 1 was used.
[0165]
Thereafter, a resin film 60α was attached to both surfaces of the substrate. The resin film 60α is the same as the resin film 40α.
[0166]
(10) By repeating the steps (4) to (8) above, a further upper conductor circuit 68 (including the via hole 66) is formed, and then the surface of the conductor circuit 66 is etched to roughen the surface. By forming a chemical surface (not shown), a multilayer wiring board having a conductor circuit formed on the outermost layer was obtained.
[0167]
(11) In the same manner as (11) to (14) in Example 1, the multilayer printed wiring board 110 having the capacitor 120 and having the solder bumps 76 was obtained (see FIG. 9).
[0168]
Example 3
In Example 2, as a capacitor, the dielectric surface of a commercially available chip capacitor (Murata Manufacturing Co., Ltd., GPM33) was coated with a resin, and then a sulfuric acid solution having a concentration of 15% by weight and a temperature of 25 ° C. was sprayed on the metal layer. A multilayer printed wiring board was produced in the same manner as in Example 2 except that the acid treatment was performed for 5 minutes and then the coated resin was peeled off, that is, a capacitor having an acid treatment only on the metal layer surface was used. .
The contact angle of the capacitor surface before acid treatment was 52 ° on the metal layer surface and 57 ° on the dielectric surface, and the contact angle on the metal layer surface after acid treatment was 14 °.
[0169]
(Example 4)
In Example 2, as a capacitor, the surface of a metal layer of a commercially available chip capacitor (Murata Manufacturing Co., Ltd., GPM33) is coated with a resin, and then a sulfuric acid solution having a concentration of 15% by weight and a temperature of 25 ° C. is sprayed on the dielectric surface. A multilayer printed wiring board is manufactured in the same manner as in Example 2 except that a capacitor that has been subjected to acid treatment for 5 minutes and then the coated resin is peeled off, that is, a capacitor that has been subjected to acid treatment only on the dielectric surface is used. did.
The contact angle of the capacitor surface before acid treatment was 52 ° on the metal layer surface and 57 ° on the dielectric surface, and the contact angle on the dielectric surface after acid treatment was 14 °.
[0170]
(Example 5)
(1) A bismaleimide-triazine (BT) resin plate 30α having a through-hole 37 for incorporating a capacitor was used as a starting material (see FIG. 14A).
[0171]
(2) Next, the capacitor 220 was attached to the through-hole formed in the laminated plate 30α with an adhesive (thermosetting resin) interposed therebetween to obtain the substrate 30 having the capacitor 220 built therein (see FIG. 14B). ).
The capacitor 220 is degreased by immersing a commercially available chip capacitor (Murata Manufacturing Co., Ltd., GPM33) in an alkaline cleaning solution (KOH: 15 vol%) at a liquid temperature of 50 ° C. for 3 minutes, and then an acid solution (sulfuric acid: 10 vol). %) And neutralized with a washing treatment. The contact angle of the capacitor surface before the cleaning treatment is 52 ° on the surface of the metal layer 26 and the surface of the dielectric 23 is 57 °. The contact angle after the cleaning treatment is 12 ° on the surface of the metal layer 26 and the dielectric 23. The surface was 14 ° (see FIG. 1B).
[0172]
(3) Next, the resin film 40α is laminated and pressed on the upper and lower sides of the substrate 30 containing the capacitor 220, and then heat-cured, and a cured layer 40β of resin film is formed on both surfaces of the substrate containing the capacitor 220. It formed (refer FIG.14 (c) and (d)).
As the resin film 40α, a resin film made of a thermosetting cycloolefin resin was used.
[0173]
(4) Hereinafter, using the same method as (4) to (11) in Example 2, a multilayer printed wiring board 210 having a capacitor 220 and having solder bumps 76 was obtained (see FIG. 13).
In the second embodiment, the multilayer printed wiring board is manufactured so that only the upper surfaces of the first and second electrodes 21 and 22 of the capacitor 120 are connected to the via hole. However, in the present embodiment, the first of the capacitor 220 is manufactured. The multilayer printed wiring board was manufactured so that the second electrodes 21 and 22 and the upper and lower surfaces were connected to the via holes.
[0174]
About the multilayer printed wiring board obtained in Examples 1-5, after performing a heat cycle test on the following conditions, by the following evaluation method, the presence or absence of generation | occurrence | production of peeling between a capacitor | condenser and adhesive agent, in adhesive agent The presence or absence of occurrence of cracks in the substrate, the presence or absence of occurrence of short circuit or disconnection, and the presence or absence of swelling of the interlayer resin insulation layer were evaluated. The results are shown in Table 1.
[0175]
Heat cycle test (reliability test)
The obtained multilayer printed wiring board was maintained in an atmosphere at 130 ° C. for 3 minutes, and then a cycle in which the multilayer printed wiring board was maintained in an atmosphere at −65 ° C. for 3 minutes was repeated 1000 times and 2000 times.
[0176]
Evaluation methods
(1) Presence or absence of peeling between the capacitor and adhesive
The multilayer printed wiring board was cut with a cutter, and the cut section was observed with a microscope. Here, the multilayer printed wiring board was cut so as to cut the capacitor.
The results are shown in Table 1 below.
[0177]
(2) Presence or absence of cracks in the adhesive
The multilayer printed wiring board was cut in the same manner as in (1) above, and the cross section was observed with a microscope. The results are shown in Table 1 below.
[0178]
(3) Presence or absence of short circuit or disconnection
After mounting the IC chip on the multilayer printed wiring board, a continuity test was performed, and the continuity state was evaluated from the results displayed on the monitor. The results are shown in Table 1 below.
(4) Interstitial resin insulation layer presence or absence of swelling
The multilayer printed wiring board was cut in the same manner as in (1) above, and the cross section was observed with a microscope. The results are shown in Table 1 below.
[0179]
(5) Capacitance measurement before and after reliability test
The capacitance of the capacitor was measured before and after the reliability test using a picoammeter. The results are shown in Table 2 below.
[0180]
[Table 1]

[0181]
[Table 2]

[0182]
As shown in Table 1, for the multilayer printed wiring boards obtained in Examples 1 to 5, when a heat cycle test of 1000 cycles was performed, no peeling between the capacitor and the adhesive occurred, There were no cracks in the adhesive.
Further, no short circuit, disconnection, or swelling of the interlayer resin insulation layer occurred.
[0183]
In addition, when the heat cycle test of 2000 cycles was performed, in the multilayer printed wiring board obtained in Example 3, peeling occurred between the capacitor and the adhesive on a part of the dielectric surface. Although a slight crack was also generated in the adhesive, it did not affect the product, and no short circuit, disconnection, or swelling of the interlayer resin insulation layer occurred.
Further, in the multilayer printed wiring board obtained in Example 4, peeling between the capacitor and the adhesive occurred on a part of the metal layer surface, and a slight crack was generated in the adhesive. However, it did not affect the product, and no short circuit, disconnection, or swelling of the interlayer resin insulation layer occurred.
[0184]
Further, in the multilayer printed wiring boards obtained in Examples 1, 2, and 5, peeling between the capacitor and the adhesive did not occur, and no cracks occurred in the adhesive.
Also in this case, no short circuit, disconnection, or swelling of the interlayer resin insulation layer occurred.
[0185]
Further, as shown in Table 2, the capacitors embedded in the substrates in Examples 1 to 5 have little change in capacitance before and after the reliability test, and the electrical connection is also made between the conductor circuit and the capacitor. There is almost no influence.
[0186]
【The invention's effect】
As described above, the capacitor according to the first aspect of the present invention has a contact angle of 7 to 45 ° on at least a part of the surface thereof. Adhesive with adhesive used for high-power, suitable for capacitors built into multilayer printed wiring boards without causing separation between capacitors and adhesives or cracks in the adhesives It is.
[0187]
In addition, since the capacitor of the second aspect of the present invention has a coating layer formed on at least a part of the surface thereof, when incorporated in the substrate of the multilayer printed wiring board, the adhesive used when incorporating the Therefore, it is suitable for a capacitor to be built in a multilayer printed wiring board without causing peeling between the capacitor and the adhesive or cracking in the adhesive.
[0188]
Further, since the multilayer printed wiring board of the present invention has a built-in capacitor, the distance between the IC chip and the capacitor is short, and even when an IC chip driven at a high frequency is mounted, the loop inductance is sufficiently low.
Further, the built-in capacitor is the capacitor according to the first or second aspect of the present invention, and is subjected to plasma treatment, acid treatment, cleaning treatment or the like, or a coating layer is formed. No peeling occurs between them and no cracks occur in the adhesive. Therefore, the multilayer printed wiring board is excellent in electrical connectivity and reliability without disconnecting the connection between the capacitor terminal and the via hole or causing the interlayer resin insulation layer to swell.
[Brief description of the drawings]
1A to 1B are cross-sectional views schematically showing an example of carbon of the present invention.
FIG. 2 is a cross-sectional view schematically showing an example of a multilayer printed wiring board according to the present invention.
3 is a cross-sectional view schematically showing a state in which an IC chip is mounted on the multilayer printed wiring board shown in FIG. 2 and attached to a daughter board.
FIGS. 4A to 4D are cross-sectional views schematically showing manufacturing steps of the multilayer printed wiring board of the present invention. FIGS.
FIGS. 5A to 5C are cross-sectional views schematically showing manufacturing steps of the multilayer printed wiring board of the present invention.
6A to 6C are cross-sectional views schematically showing manufacturing steps of the multilayer printed wiring board of the present invention.
7A to 7C are cross-sectional views schematically showing manufacturing steps of the multilayer printed wiring board of the present invention.
8A to 8C are cross-sectional views schematically showing manufacturing steps of the multilayer printed wiring board of the present invention.
FIG. 9 is a cross-sectional view schematically showing another example of the multilayer printed wiring board of the present invention.
FIGS. 10A to 10D are cross-sectional views schematically showing manufacturing steps of the multilayer printed wiring board of the present invention.
11A to 11C are cross-sectional views schematically showing manufacturing steps of the multilayer printed wiring board of the present invention.
FIGS. 12A to 12C are cross-sectional views schematically showing manufacturing steps of the multilayer printed wiring board of the present invention.
FIG. 13 is a sectional view schematically showing still another example of the multilayer printed wiring board of the present invention.
14A to 14D are cross-sectional views schematically showing manufacturing steps of the multilayer printed wiring board of the present invention.
FIGS. 15A and 15B are explanatory diagrams of loop inductance of a conventional multilayer printed wiring board, and FIG. 15C is an explanatory diagram of loop inductance of the multilayer printed wiring board of the present invention.
[Explanation of symbols]
10, 110, 210 Multilayer printed wiring board
20, 120, 220 capacitor
21 First electrode
22 Second electrode
23 Dielectric
24 First conductive film
25 Second conductive film
26, 226, 326 metal layer
27, 227, 327 Rough surface
30 substrates
40, 60 interlayer resin insulation layer
46, 66 Via hole
48, 68 conductor circuit
70 Solder resist layer
76 Solder bump
90 IC chip

Claims (3)

A multilayer in which an interlayer resin insulating layer and a conductor circuit are sequentially formed on a substrate in which a capacitor is built in or accommodated in a cavity, and the capacitor, the conductor circuit, and the upper and lower conductor circuits are connected via via holes. A printed wiring board,
At least a part of the surface of the capacitor is subjected to at least one of plasma treatment, cleaning treatment and acid treatment, and then a coating layer is formed.
The substrate is a substrate having a cavity,
The multilayer printed wiring board, wherein the coating layer formed on the surface of the capacitor is bonded to an inner wall surface of a cavity formed on the substrate .   The coating layer is a method in which a vinyl monomer or the like is graft-polymerized on the dielectric surface, a method in which an active group is generated on the dielectric surface by a mechanical treatment such as ultrasonic treatment, and the active group reacts with the polymer. The multilayer printed wiring board according to claim 1, wherein the multilayer printed wiring board is formed by a method of reacting a hydroxyl group present on the dielectric surface with vinyltrichlorosilane or vinyltriethoxysilane.   The multilayer printed wiring board according to claim 1, wherein the coating layer formed on the surface of the capacitor is bonded to the inner wall surface of the cavity via an adhesive.

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