JP3795460B2 - Printed wiring board, semiconductor device, and printed wiring board manufacturing method - Google Patents

Description

【００８１】
電極間における誘電体膜の厚みＴ１＋Ｔ２は、導電体膜２および５の周縁部と中央部とにおいて誘電体膜の厚みをそれぞれ測定し、その測定値を平均することにより求めた。また、１（Ｖ）の直流電圧のテスターにより電極間の導通をチェックして短絡の有無を調べた。そして、短絡していないコンデンサにおいて、コンデンサの容量密度、および静電容量のばらつきの評価を行なった。
【００８２】
導電体膜２および５にインピーダンスアナライザを接続し、測定周波数１（ＭＨｚ）、振幅１（Ｖ）の信号を用いて各々のコンデンサの静電容量を測定した。そして、この静電容量の値をＸ線透過観察によって導き出した導電体膜２および５の面積で割り、コンデンサの容量密度を求めた。表１には、このようにして求められたコンデンサの容量密度の平均値を示した。
【００８３】
また、測定された各々のコンデンサの静電容量の値から標準偏差を導出し、その標準偏差の３倍の値をコンデンサの静電容量の平均値で割ることによって、静電容量のばらつきを求めた。
【００８４】
表１を参照して、実施品１から３のプリント配線板には６μｍの厚みを有するフィルム状誘電体膜４を設けた。これに対して、比較品１から３のプリント配線板には、フィルム状誘電体膜４を設けなかった。この結果、実施品１から３のプリント配線板では静電容量のばらつきを低く抑えることができたが、比較品１および２のプリント配線板では、静電容量のばらつきが大きくなった。また、誘電体膜の厚みが小さかった比較品１のプリント配線板では７８４個中２１個のコンデンサで短絡が発生した。以上のことから、フィルム状誘電体膜４を設けることによって、電極間の短絡を防止し、かつ静電容量のばらつきを抑制できることを確認できた。
【００８５】
なお、比較品３のプリント配線板では、フィルム状誘電体膜４を設けなかったにもかかわらず、静電容量のばらつきを抑制することができた。これは、比較品３のプリント配線板では、誘電体膜の厚みが十分に大きく、基材１上の凹凸による影響をあまり受けなかったためと考えられる。しかし、比較例３のプリント配線板では、コンデンサの容量密度が小さくなり、コンデンサをプリント配線板に高密度に内蔵できないという問題が生じた。
【００８６】
また、実施品１から３のプリント配線板では、誘電体膜の厚みＴ１＋Ｔ２に対する接着剤３の厚みＴ１の割合が、０．４以下であるのに対して、比較品４のプリント配線板では、０．４を超え０．６０とした。この結果、比較品４のプリント配線板ではコンデンサの静電容量のばらつきを十分に抑制できなかった。このことから、誘電体膜の厚みＴ１＋Ｔ２に対する接着剤３の厚みＴ１の割合を、０＜Ｔ１／（Ｔ１＋Ｔ２）≦０．４の範囲内に設定することによって、コンデンサの静電容量のばらつきを十分に抑制できることを確認できた。
【００８７】
また、実施品４のプリント配線板では、図１０に示すプリント配線板２０と同様に導電体膜５に接触する接着剤３ａを設けず、導電体膜２に接触する接着剤３のみを設けた。しかし、この場合であっても、導電体膜５に十分に密着するようにフィルム状誘電体膜４を設けておけば、コンデンサの静電容量のばらつきを十分に抑制し、かつ電極間の短絡を防止するコンデンサを内蔵するプリント配線板を実現できることを確認できた。
【００８８】
今回開示された実施の形態および実施例はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。
【００８９】
【発明の効果】
以上説明したように、この発明に従えば、ばらつきのない所望の容量密度で形成されるとともに、互いに向い合う電極間で発生する短絡を確実に防止できるコンデンサを内蔵するプリント配線板、そのプリント配線板を備える半導体装置、およびそのプリント配線板の製造方法を提供することができる。
【図面の簡単な説明】
【図１】 この発明の実施の形態１におけるプリント配線板を示す断面図である。
【図２】 図１中に示すプリント配線板の製造方法の第１工程を示す断面図である。
【図３】 図１中に示すプリント配線板の製造方法の第２工程を示す断面図である。
【図４】 図１中に示すプリント配線板の製造方法の第３工程を示す断面図である。
【図５】 図１中に示すプリント配線板の製造方法の第４工程を示す断面図である。
【図６】 図１中に示すプリント配線板の製造方法の第５工程を示す断面図である。
【図７】 図１中に示すプリント配線板の製造方法の第６工程を示す断面図である。
【図８】 実施の形態２におけるプリント配線板の製造方法の第１工程を示す断面図である。
【図９】 実施の形態２におけるプリント配線板の製造方法の第２工程を示す断面図である。
【図１０】 この発明の実施の形態３におけるプリント配線板を示す断面図である。
【図１１】 図１０中に示すプリント配線板の製造方法の第１工程を示す断面図である。
【図１２】 図１０中に示すプリント配線板の製造方法の第２工程を示す断面図である。
【図１３】 図１０中に示すプリント配線板の製造方法の第３工程を示す断面図である。
【図１４】 図１０中に示すプリント配線板の製造方法の第４工程を示す断面図である。
【図１５】 図１０中に示すプリント配線板の製造方法の第５工程を示す断面図である。
【図１６】 この発明の実施の形態４における半導体装置を示す断面図である。
【符号の説明】
１，６ 基材、１ａ 主表面、２，５ 導電体膜、３，３ａ，３ｂ 接着剤、４ フィルム状誘電体膜、１０，２０ プリント配線板、３０ 半導体装置、３２ 半導体チップ、３３ 多層プリント配線板。[0001]
BACKGROUND OF THE INVENTION
The present invention generally relates to a printed wiring board, a semiconductor device including the printed wiring board, and a method for manufacturing the printed wiring board, and more specifically, a printed wiring board including a capacitor element, and the printed wiring board. The present invention relates to a semiconductor device provided and a method for manufacturing the printed wiring board.
[0002]
[Prior art]
Multilayer printed wiring boards with high wiring density are manufactured by a so-called build-up method. In the manufacturing process of a multilayer printed wiring board by the build-up method, an insulator layer and a conductor layer are stacked in order on the core substrate. At this time, holes are successively formed at predetermined positions, and the holes are filled with a conductive resin or are plated with metal to obtain electrical connection between layers. In the method of electrically connecting the layers by through holes, it is necessary to make holes that penetrate all the conductor layers, whereas in the build-up method, only between the conductor layers that require electrical connection. What is necessary is just to make a hole. For this reason, according to the multilayer printed wiring board manufactured by the build-up method, it is possible to realize high density wiring.
[0003]
In such a multilayer printed wiring board, there is a case in which a parallel plate capacitor having a conductive layer facing each other as a capacitor electrode and an insulating layer provided between the conductive layers facing each other as a dielectric is incorporated. is there. And the multilayer printed wiring board which incorporated the capacitor | condenser in this way is disclosed by the patent 2738590 specification as a capacitive printed wiring board (patent document 1).
[0004]
The capacitive printed wiring board disclosed in Patent Document 1 includes a capacitor laminate inside a printed wiring board. The capacitor laminate is composed of a pair of conductive sheets provided at a predetermined interval and a dielectric sheet provided between the pair of conductive sheets. The conductive sheet is formed from a conductive material, preferably copper, and the dielectric sheet is formed from a ceramic filled with, for example, an epoxy. A device is attached to the surface of the capacitive printed wiring board, and the device is connected to a pair of conductive sheets via a power line and a ground line.
[0005]
Moreover, a multilayer printed wiring board with a built-in capacitor is disclosed as a multilayer board in Japanese Patent Application Laid-Open No. 2002-204073 (Patent Document 2).
[0006]
The multilayer board disclosed in Patent Document 2 includes a film having a circuit formed on the surface thereof, a fiber reinforced resin layer provided on both surfaces of the film, and an outer layer circuit provided on the fiber reinforced resin layer. To form a capacitor circuit in the film, the film is filled with a high dielectric constant inorganic powder such as lead zirconate titanate (PZT). In this case, the capacitance of the capacitor can be kept large and constant by using a thin film having a constant thickness.
[0007]
[Patent Document 1]
Japanese Patent No. 2738590
[0008]
[Patent Document 2]
JP 2002-204073 A
[0009]
[Problems to be solved by the invention]
In the capacitive printed wiring board disclosed in Patent Document 1, an epoxy that is a thermosetting resin is used for a dielectric sheet that serves as a dielectric of a capacitor laminate. When manufacturing a capacitor laminate, a pair of conductive sheets is placed until a distance between the pair of conductive sheets reaches a predetermined value by placing a fluid epoxy between the pair of conductive sheets. Press. Thereafter, the epoxy is cured by applying heat to the epoxy to complete the capacitor laminate.
[0010]
However, it is difficult to accurately control the distance between the pair of conductive sheets in a state where an epoxy having fluidity is arranged. That is, during the step of pressing the pair of conductive sheets, an excess portion of the epoxy disposed between the pair of conductive sheets moves from the central portion of the conductive sheet to the outer peripheral portion and is discharged to the outside. For this reason, the thickness of the dielectric sheet tends to increase at the central portion of the conductive sheet, and the thickness of the dielectric sheet tends to decrease at the outer peripheral portion. Since the capacitance density of the capacitor is determined by the distance between the pair of conductive sheets and the dielectric constant of the dielectric sheet, the distance between the pair of conductive sheets is not accurately controlled, so that the capacitor can have a desired capacitance density. In other words, there is a problem that the capacitor cannot be formed or the capacitance density of the capacitor varies.
[0011]
In order to increase the capacitance density of the capacitor, it is necessary to reduce the distance between the pair of conductive sheets. However, as described above, since it is difficult to accurately control the distance between the pair of conductive sheets, a portion that is too close to the planned distance may occur. In this case, defects such as pinholes, cracks or voids may occur in the dielectric sheet in that portion, or a pair of conductive sheets may come into contact with each other to cause a short circuit. In particular, since the film thickness of the dielectric sheet tends to be small at the outer peripheral portion of the conductive sheet, such a problem is likely to occur, and the withstand voltage of the capacitor cannot be sufficiently secured.
[0012]
In the multilayer board disclosed in Patent Document 2, a capacitor circuit is formed by filling a film with inorganic powder having a high dielectric constant. However, this high dielectric constant inorganic powder is usually added to an epoxy resin or the like and filled into a film in a fluid state. For this reason, there exists a possibility that the problem demonstrated above may generate | occur | produce similarly.
[0013]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problem, and is a printed wiring that has a capacitor with a built-in capacitor that can be formed with a desired capacitance density without variation and that can reliably prevent a short circuit between electrodes facing each other It is providing a board, a semiconductor device provided with the printed wiring board, and a manufacturing method of the printed wiring board.
[0014]
[Means for Solving the Problems]
The printed wiring board according to the present invention is provided between the first and second conductive films facing each other, the first conductive film and the second conductive film, and the first and second conductive films. A first dielectric film in contact with at least one of the conductor films, and a condition between the first conductor film and the second conductor film, wherein the first dielectric film has fluidity. And a second dielectric film in a solid state. When the thicknesses of the first and second dielectric films are T1 and T2, the relationship 0 <T1 / (T1 + T2) ≦ 0.4 is satisfied.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0016]
(Embodiment 1)
1 is a cross-sectional view showing a printed wiring board according to Embodiment 1 of the present invention. Referring to FIG. 1, printed wiring board 10 includes a base material 1 having a main surface 1 a, a conductor film 2 provided on the main surface 1 a of the base material 1, and a base material 1 and a conductor film 2. The substrate 6 and the conductor film 5 face each other, and the adhesive 3a, the film-like dielectric film 4 and the adhesive 3b provided between the conductor films 2 and 5 are provided. Inside the printed wiring board 10 is a capacitor having conductive films 2 and 5 facing each other as electrodes, and an adhesive 3a, a film-like dielectric film 4 and an adhesive 3b provided between the electrodes as dielectrics. It is configured.
[0017]
On the main surface 1a of the base material 1, the conductor film 2 is provided so as to protrude from the main surface 1a. The substrate 1 is made of glass epoxy. The conductor film 2 is made of copper and has a thickness of T3. In the present embodiment, the substrate 1 is formed of glass epoxy, but may be formed of glass bismaleimide triazine, glass polyphenylene oxide, polyimide, paper phenol, alumina, or the like instead of glass epoxy.
[0018]
An adhesive 3 b is provided so as to cover the main surface 1 a of the substrate 1 and the conductor film 2 exposed from the conductor film 2. A film-like dielectric film 4 and an adhesive 3a are sequentially laminated on the adhesive 3b. The top surface of the adhesive 3a is formed flat.
[0019]
Adhesives 3a and 3b are 1 × 10 at a temperature of 150 ° C. ^Five It has a viscosity of (P) and is formed from a thermosetting epoxy resin that cures at a temperature of 180 (° C.). The film-like dielectric film 4 is made of polyphenylene sulfide having a relative dielectric constant of 3. During the manufacturing process of the printed wiring board 10 in which the adhesives 3a and 3b are laminated at predetermined positions, the adhesives 3a and 3b have fluidity. Under the condition that the adhesives 3a and 3b have fluidity, the film-like dielectric film 4 is in a solid state.
[0020]
The adhesives 3a and 3b are formed from other materials that have fluidity under the conditions at the time of lamination and excellent adhesion to the conductor film 2, the substrate 1, and the film-like dielectric film 4. Also good. Examples of such materials include bismaleimide triazine resin, urethane resin, melamine resin, silicon resin, polyacrylic resin, urea resin, and phenol resin.
[0021]
Further, the film-like dielectric film 4 may be formed from other materials that do not melt or decompose under the condition that the adhesives 3a and 3b have fluidity. Examples of such materials include polyphenyl sulfone, polyimide, polyether imide, polyphenyl oxide, polyamide, polycarbonate, liquid crystal polyester, polyester, polyvinyl chloride, polysilane, polyethyl ether ketone, acetate, or polypropylene.
[0022]
A conductor film 5 is provided on the top surface of the adhesive 3 a at a position facing the conductor film 2. The conductor film 5 is made of copper. A substrate 6 is provided so as to cover the top surface of the adhesive 3 a exposed from the conductor film 5 and the conductor film 5. The base material 6 is formed of a material such as glass epoxy as with the base material 1. In this embodiment, the conductor films 2 and 5 are made of copper. However, the conductor films 2 and 5 may be made of a material having sufficient conductivity to function as an electrode of a capacitor. Examples of such a material include conductive polymers such as other metals or polythiophene.
[0023]
Adhesive 3b, film-like dielectric film 4 and adhesive 3a provided at positions where conductor films 2 and 5 face each other have thicknesses T1b, T2 and T1a, respectively. The adhesive 3 is constituted by the adhesives 3a and 3b, and the adhesive 3 has a thickness of T1 = T1a + T1b. That is, a dielectric film having a thickness of T = T1 + T2 is provided between the conductor films 2 and 5. The ratio T1 / T of the thickness of the adhesive 3 to the thickness of the dielectric film satisfies the relationship 0 <T1 / T ≦ 0.4.
[0024]
The capacitance density of the capacitor constituted by the conductive films 2 and 5 facing each other, the adhesives 3a and 3b and the film-like dielectric film 4 provided between the conductive films 2 and 5 is shown below ( It is obtained by the equation (1). Note that the capacitance density of a capacitor refers to a capacitance per unit area of the capacitor. Further, since the additive rule of the dielectric constant is established between the adhesives 3a and 3b and the film-like dielectric film 4, the dielectric constant ε of the dielectric film in the equation (1) can be obtained.
[0025]
Capacitance density = dielectric constant ε of dielectric film / thickness T of dielectric film (1)
Therefore, the adhesives 3a and 3b constituting the dielectric film and the film-like dielectric are provided on the condition that the ratio of the thickness of the adhesive 3 to the thickness of the dielectric film satisfies the relationship of 0 <T1 / T ≦ 0.4. By setting the thickness of the body film 4 to a predetermined thickness, a desired capacitance density can be obtained with a capacitor. Furthermore, in this embodiment, the film-like dielectric film 4 is formed from polyphenylene sulfide and the adhesive 3 is formed from glass epoxy. However, the film-like dielectric film 4 and the adhesive 3 are made of materials having appropriate dielectric constants. Thus, the capacitance density of the capacitor can be set to a desired value.
[0026]
Printed wiring board 10 according to the first embodiment of the present invention includes conductive films 2 and 5 as first and second conductive films facing each other, and between conductive film 2 and conductive film 5. The adhesives 3a and 3b as the first dielectric films that are in contact with at least one of the conductor films 2 and 5, and the conductors 3 and 5 are provided between the conductor film 2 and the conductor film 5. And 3b are provided with a film-like dielectric film 4 as a second dielectric film that is in a solid state under the condition that it has fluidity. When the thicknesses of the adhesives 3a and 3b and the film-like dielectric film 4 are T1 and T2, the relationship of 0 <T1 / (T1 + T2) ≦ 0.4 is satisfied.
[0027]
The printed wiring board 10 further includes a base material 1 having a main surface 1a provided with a conductor film 2 protruding therefrom. Adhesive 3b is provided to cover conductor film 2 and main surface 1a.
[0028]
Note that the printed wiring board 10 can be used as a multilayer printed wiring board by alternately stacking the insulating layers and the conductive layers on the conductive film 5 alternately in layers and sequentially obtaining electrical connection between the layers. Can do.
[0029]
2-7 is sectional drawing which shows the process of the manufacturing method of the printed wiring board shown in FIG. A method for manufacturing the printed wiring board 10 shown in FIG. 1 will be described with reference to FIGS.
[0030]
Referring to FIG. 2, copper plating is performed on main surface 1a of substrate 1 to form copper foil 11 having thickness T3. Instead of performing copper plating on the substrate 1, a double-sided copper-clad plate may be used.
[0031]
Referring to FIG. 3, a resist film (not shown) having a predetermined pattern shape is formed on copper foil 11. Using this resist film as a mask, the copper foil 11 is etched to remove a part of the copper foil 11. Thereafter, the resist film (not shown) is removed. Thereby, the conductor film 2 having a thickness T3 is formed on the main surface 1a of the substrate 1.
[0032]
Referring to FIG. 4, apart from the step performed on substrate 1 shown in FIGS. 2 and 3, adhesives 3a and 3b having thicknesses t1a and t1b are formed on both surfaces of film-like dielectric film 4 having thickness T2. Provide. At this stage, the adhesive 3 constituting the adhesives 3a and 3b has a thickness of t1 = t1a + t1b. Thereby, the laminated body of the dielectric film which consists of the adhesive agent 3a, the film-form dielectric film 4, and the adhesive agent 3b is formed.
[0033]
Even if the surface of the film-like dielectric film 4 is subjected to corona discharge treatment, ozone treatment, oxygen plasma treatment or the like to improve the paintability and adhesion between the film-like dielectric film 4 and the adhesives 3a and 3b. good. Further, for the purpose of protecting the laminated body of dielectric films, a cover film (not shown) is laminated on the surfaces of the adhesives 3a and 3b until the next process.
[0034]
Referring to FIG. 5, a copper foil 12 is prepared. Each member is positioned so that the laminate of the dielectric film composed of the adhesive 3a, the film-like dielectric film 4 and the adhesive 3b is sandwiched between the base material 1 on which the conductor film 2 is formed and the copper foil 12. To do.
[0035]
In this state of positioning, both surfaces of the substrate 1 and the copper foil 12 are sandwiched between pressure plates, and pressing by vacuum hot pressing is performed. At this time, pressing is performed until the thicknesses t1a and t1b of the adhesives 3a and 3b become the thicknesses T1a and T1b at the positions where the conductor film 2 and the copper foil 12 face each other.
[0036]
A stainless steel (SUS) plate having a thickness of 2 mm is used as the pressure plate used in the vacuum hot press, the heating rate is 3 (° C./min), and the maximum temperature is 180 (° C.). In this embodiment, a vacuum hot press is used. However, a hot press, a laminator, or a combination thereof may be used as appropriate instead of the vacuum hot press.
[0037]
Referring to FIG. 6, adhesives 3 a and 3 b are cured by the process shown in FIG. 5, and copper foil 12, dielectric film laminate, and substrate 1 on which conductor film 2 is formed are integrated. Turn into.
[0038]
Referring to FIG. 7, a resist film (not shown) having a predetermined pattern shape is formed on copper foil 12. Using the resist film as a mask, the copper foil 12 is etched to remove a part of the copper foil 12. Thereafter, the resist film (not shown) is removed. Thereby, the conductor film 5 is formed on the adhesive 3a.
[0039]
Referring to FIG. 1, base material 6 made of glass epoxy is formed so as to cover conductor film 5 and the top surface of adhesive 3 a exposed from conductor film 5. Through the above steps, the printed wiring board 10 shown in FIG. 1 is completed.
[0040]
In the manufacturing method of the printed wiring board 10 according to the first embodiment of the present invention, the adhesive 3 having fluidity and thickness t1 between the conductor film 2 and the conductor film 5, and the solid The step of positioning the film-like dielectric film 4 having a thickness of T2 and the conductive material until the thickness t1 of the adhesive 3 becomes T1 satisfying the relationship of 0 <T1 / (T1 + T2) ≦ 0.4. A step of pressing the body film 2 and the conductor film 5 and a step of curing the adhesive 3 after the pressing step are provided.
[0041]
According to the printed wiring board 10 configured as described above and the manufacturing method thereof, the dielectric of the capacitor built in the printed wiring board 10 is bonded to the adhesives 3a and 3b having fluidity during lamination during the manufacturing process. And a film-like dielectric film 4 in a solid state. For this reason, the film-like dielectric film 4 serves as a spacer during the pressing step shown in FIG. 5 and prevents a short circuit between the electrodes caused by contact between the conductor films 2 and 5. In particular, in order to obtain a larger capacity density in the capacitor, it is necessary to reduce the distance between the conductor films 2 and 5, but even in such a case, it is certain that a short circuit will occur between the electrodes. Can be prevented.
[0042]
In the process shown in FIG. 5, the adhesives 3a and 3b flow on the main surface 1a of the substrate 1 until the thicknesses change from t1a and t1b to T1a and T1b, respectively. At this time, unevenness on the main surface 1a of the substrate 1 causes variations in the pressure applied during pressing, and a difference in the amount of flow of the adhesives 3a and 3b occurs. This causes the thickness of the dielectric film after pressing to be non-uniform and cause the capacitance density of the capacitor to vary. In particular, when it is desired to reduce the thickness of the dielectric film, the influence of the difference in the flow rate of the adhesives 3a and 3b becomes relatively large, and the capacitance density of the capacitor varies greatly.
[0043]
However, by using the film-like dielectric film 4, the thickness of the adhesives 3a and 3b can be reduced while keeping the capacitance density of the capacitors the same. As a result, it is possible to realize the printed wiring board 10 incorporating the capacitor formed with a desired capacitance density without variation.
[0044]
Further, the ratio T1 / T of the thickness of the adhesive 3 to the thickness of the entire dielectric film satisfies the relationship of 0 <T1 / T ≦ 0.4. When T1 / T is larger than 0.4, the ratio of the thickness of the adhesive 3 having fluidity to the thickness of the entire dielectric film becomes too large, and the above-described film-shaped dielectric film 4 is used. The effect of cannot be obtained sufficiently. Therefore, by setting T1 / T within the range of 0 <T1 / T ≦ 0.4, variations in the capacitance density of the capacitor can be sufficiently suppressed.
[0045]
Further, the adhesive 3 b is provided in contact with the conductor film 2 protruding from the main surface 1 a of the substrate 1. And when the adhesive agent 3b is laminated | stacked so that the conductor film 2 and the base material 1 may be covered, the adhesive agent 3b has fluidity | liquidity. For this reason, the adhesiveness between the adhesive 3b, the conductor film 2 and the substrate 1 can be ensured, and further, it is possible to prevent defects such as pinholes, cracks or voids from occurring in the dielectric film. Thereby, the capacitor provided in the printed wiring board 10 can be operated in a desired state.
[0046]
(Embodiment 2)
The printed wiring board according to the second embodiment of the present invention has the same structure as that of the printed wiring board 10 according to the first embodiment. However, the process of manufacturing the printed wiring board in the second embodiment is different from the printed wiring board 10 in the first embodiment.
[0047]
8 and 9 are cross-sectional views showing the steps of the method for manufacturing a printed wiring board in the second embodiment. The steps shown in FIGS. 2 and 3 of the method for manufacturing printed wiring board 10 in the first embodiment are followed by the steps shown in FIGS. Further, this is followed by the steps shown in FIGS. 6, 7 and 1 of the method for manufacturing printed wiring board 10 in the first embodiment. In the following, description of overlapping manufacturing steps is omitted.
[0048]
Referring to FIG. 8, adhesive 3a having thickness t1a, dielectric film 4 having thickness T2 and adhesive 3b having thickness t1b are sequentially laminated on the surface of copper foil 12.
[0049]
Referring to FIG. 9, a laminate composed of adhesive 3 b, film-like dielectric film 4, adhesive 3 a and copper foil 12 so that conductor film 2 formed on substrate 1 and adhesive 3 b face each other. Position the body. In this state of positioning, both surfaces of the substrate 1 and the copper foil 12 are sandwiched between pressure plates, and pressing by vacuum hot pressing is performed. At this time, pressing is performed until the thicknesses t1a and t1b of the adhesives 3a and 3b become the thicknesses T1a and T1b at the position where the conductor film 2 and the copper foil 12 face each other.
[0050]
In the method for manufacturing a printed wiring board according to the second embodiment of the present invention, the steps of positioning the adhesives 3a and 3b and the film-like dielectric film 4 include the steps of positioning the adhesives 3a and 3b and the film-like dielectric on the conductor film 5. A step of forming a laminate in which the body film 4 is laminated; and a step of laminating the laminate on the conductor film 2.
[0051]
According to the method of manufacturing a printed wiring board configured as described above, the adhesive 3a, the film-like dielectric film 4 and the adhesive 3b are sequentially laminated on the basis of the highly rigid copper foil 12. For this reason, although each of the adhesive 3a, the film-like dielectric film 4 and the adhesive 3b has low rigidity, it becomes easy to bundle these laminates during the pressing step shown in FIG. Further, it is not necessary to provide a cover film for protecting the adhesive 3a on the surface of the adhesive 3a on the side where the copper foil 12 is previously provided. For the above reasons, the printed wiring board manufacturing process can be made easier and simpler.
[0052]
(Embodiment 3)
FIG. 10 is a sectional view showing a printed wiring board according to Embodiment 3 of the present invention. Referring to FIG. 10, printed wiring board 20 has basically the same structure as printed wiring board 10 in the first embodiment. In the following, description of overlapping structures is omitted.
[0053]
An adhesive 3 is provided so as to cover the main surface 1a of the substrate 1 and the conductor film 2 exposed from the conductor film 2. A film-like dielectric film 4 is provided on the adhesive 3. The top surface of the film-like dielectric film 4 is formed flat. On the top surface of the film-like dielectric film 4, a conductor film 5 made of copper is provided at a position facing the conductor film 2. A substrate 6 made of glass epoxy or the like is provided so as to cover the top surface of the film-like dielectric film 4 exposed from the conductor film 5 and the conductor film 5.
[0054]
The adhesive 3 is formed from an epoxy resin or the like, and the film-like dielectric film 4 is formed from polyphenylene sulfide or the like. During the manufacturing process of the printed wiring board 20 in which the adhesive 3 is laminated at a predetermined position, the adhesive 3 has fluidity. Under the condition that the adhesive 3 has fluidity, the film-like dielectric film 4 is in a solid state.
[0055]
The adhesive 3 and the film-like dielectric film 4 provided at positions where the conductor films 2 and 5 face each other have thicknesses T1 and T2, respectively. As a result, a dielectric film having a thickness of T = T1 + T2 is provided between the conductor films 2 and 5. The ratio T1 / T of the thickness of the adhesive 3 to the thickness of the dielectric film satisfies the relationship 0 <T1 / T ≦ 0.4.
[0056]
In printed wiring board 20 according to the third embodiment of the present invention, adhesive 3 is provided in contact with only conductive film 2 among conductive films 2 and 5.
[0057]
11 to 15 are cross-sectional views showing the steps of the method for manufacturing the printed wiring board shown in FIG. The steps shown in FIGS. 11 to 15 and FIG. 10 follow the steps shown in FIGS. 2 and 3 of the method for manufacturing printed wiring board 10 in the first embodiment. In the following, description of overlapping manufacturing steps is omitted.
[0058]
Referring to FIG. 11, film dielectric film 4 having a thickness of T2 is thermocompression bonded to the surface of copper foil 21. In providing the dielectric film 4 on the surface of the copper foil 21, a dielectric dissolved in a solvent may be applied to the surface of the copper foil 21. Further, a ceramic dielectric may be deposited on the surface of the copper foil 21 by a wet method typified by a sol-gel method. Further, a dielectric may be attached to the surface of the copper foil 21 by a vapor phase method typified by a chemical vapor deposition method, and the dielectric is formed on the surface of the copper foil 21 by anodizing the copper foil 21. Also good.
[0059]
Referring to FIG. 12, an adhesive 3 having a thickness t1 is provided on a film-like dielectric film 4. At this time, the adhesive 3 is provided so that the thickness t1 of the adhesive 3 covering the conductor film 2 is smaller than the thickness T3 of the conductor film 2 in a subsequent process.
[0060]
Referring to FIG. 13, a laminate made of adhesive 3, film-like dielectric film 4 and copper foil 21 is used as the base material so that conductor film 2 formed on base material 1 and adhesive 3 face each other. Position with respect to 1. In the state of positioning as described above, both surfaces of the substrate 1 and the copper foil 21 are sandwiched between pressure plates, and pressing by vacuum hot pressing is performed. At this time, pressing is performed until the thickness t1 of the adhesive 3 reaches the thickness T1 at the position where the conductor film 2 and the copper foil 21 face each other.
[0061]
Referring to FIG. 14, adhesive 3 is cured by the process shown in FIG. 13, and a laminate including adhesive 3, film-like dielectric film 4 and copper foil 21, and base on which conductor film 2 is formed. The material 1 is integrated.
[0062]
Referring to FIG. 15, a resist film (not shown) having a predetermined pattern shape is formed on copper foil 21. Using the resist film as a mask, the copper foil 21 is etched to remove a part of the copper foil 21. Thereafter, the resist film (not shown) is removed. Thereby, the conductor film 5 is formed on the film-like dielectric film 4.
[0063]
Referring to FIG. 10, base material 6 made of glass epoxy is formed so as to cover conductor film 5 and the top surface of adhesive 3 a exposed from conductor film 5. Through the above steps, the printed wiring board 20 shown in FIG. 10 is completed.
[0064]
In the method of manufacturing printed wiring board 20 according to the third embodiment of the present invention, conductor film 2 is provided on main surface 1a of substrate 1 and has a thickness T3, and is used as the first dielectric film. The adhesive 3 is provided so as to cover the conductor film 2 and the main surface 1a, and the thickness t1 of the adhesive 3 before pressing satisfies the relationship of t1 <T3.
[0065]
According to the printed wiring board 20 configured as described above and the manufacturing method thereof, the conductor film 5 is provided in direct contact with the film-like dielectric film 4 without using an adhesive. The conductor film 5 is not provided in a state of protruding from the base material 6, and the adhesion between the conductor film 5 and the dielectric film can be kept relatively good without using an adhesive. For this reason, the capacitor built in the printed wiring board 20 can be composed of four layers of the conductor film 5, the film-like dielectric film 4, the adhesive 3, and the conductor film 2. Thereby, while improving the yield at the time of the manufacturing process of the printed wiring board 20, the printed wiring board 20 can be manufactured cheaply through simplification of material management.
[0066]
In addition, when the thickness of the dielectric film is reduced, the tensile strength of the dielectric film is lowered, and the dielectric film may break due to a certain level of tension applied during the manufacturing process. However, when the film-like dielectric film 4 which is a dielectric film is thermally compressed on the surface of the copper foil 21, or when a dielectric dissolved in a solvent is applied to the surface of the copper foil 21, the dielectric film No tension is applied to the. For this reason, the dielectric film can be formed thinner to increase the capacitance density of the capacitor.
[0067]
In the step shown in FIG. 13, the adhesive 3 is provided so that the thickness t <b> 1 of the adhesive 3 is smaller than the thickness T <b> 3 of the conductor film 2. Thereby, the press performed in this process can be performed quickly and easily.
[0068]
That is, a part of the adhesive 3 provided on one surface of the film-like dielectric film 4 extends from the main surface 1a of the substrate 1 to the outside until the thickness of the adhesive 3 changes from t1 to T1. Leaked. However, it takes time to move the adhesive 3 on the main surface 1 a of the substrate 1. Further, since a thermosetting epoxy resin is used for the adhesive 3, curing of the adhesive 3 b starts when the adhesive 3 that flows out to the outside is still on the main surface 1 a of the substrate 1. There is a fear.
[0069]
Thus, by making the thickness t1 of the adhesive 3 before the pressing step smaller than the thickness T3 of the conductor film 2, the above-mentioned problems can be solved and the pressing step can be performed quickly and easily. In addition, when the adhesive 3 located on the conductor film 2 is pressed, it moves to the main surface 1a of the substrate 1. For this reason, in the printed wiring board 20, the top surface of the adhesive 3 is formed at a position higher than the top surface of the conductor film 2, and the above-described adhesive 3 completely covers the conductor film 2 while ensuring the form described above. The effect of can be produced.
[0070]
Under the present circumstances, thickness t1 of the adhesive agent 3 before a press process is the ratio of the area which occupies on the main surface 1a of the conductor film 2 with respect to the area of the main surface 1a of the base material 1 (henceforth, the area occupation rate of the conductor film 2). It is preferable to adjust appropriately.
[0071]
When the area occupation ratio of the conductor film 2 is relatively small, the adhesive 3 on the conductor film 2 tends to flow on the main surface 1a of the substrate 1. For this reason, more adhesive that moves onto the main surface 1a is required, and the thickness t1 of the adhesive 3 before the pressing step is a value close to the thickness T3 of the conductor film 2. Further, when the area occupation ratio of the conductor film 2 is relatively large, the adhesive 3 on the conductor film 2 is less likely to flow on the main surface 1 a of the substrate 1. For this reason, since the adhesive which moves on the main surface 1a is not so much needed, the thickness t1 of the adhesive 3 before a press process becomes a smaller value.
[0072]
For example, when the area occupation ratio of the conductor film 2 is 15%, the thickness t1 of the adhesive 3 before the pressing step is 10 μm with respect to the thickness T3 = 18 μm of the conductor film 2. However, if the area occupancy of the conductor film 2 is 10%, the thickness t1 of the adhesive 3 before the pressing step is set to a larger value, and if the area occupancy of the conductor film 2 is 50%, The thickness t1 of the adhesive 3 before the pressing step is set to a smaller value.
[0073]
(Embodiment 4)
FIG. 16 is a sectional view showing a semiconductor device according to the fourth embodiment of the present invention. Referring to FIG. 16, the semiconductor device 30 includes a multilayer printed wiring board 33 and a semiconductor chip 32 provided on the multilayer printed wiring board 33. Similar to the printed wiring board 10 in the first embodiment, the conductor film 2, the adhesive 3b, the film-like dielectric film 4, the adhesive 3a, and the conductor film 5 are sequentially laminated on the base material 1. . On the conductor film 5, insulator layers and conductor layers are alternately stacked in multiple layers, and a multilayer printed wiring board 33 having a top surface 34 is formed.
[0074]
A plurality of bumps 31 are provided on the top surface 34 of the multilayer printed wiring board 33. A semiconductor chip 32 is provided in electrical connection with the bumps 31. The bumps 31 and the conductor film 5 are electrically connected by wiring connected between the layers of the multilayer printed wiring board 33.
[0075]
A semiconductor device 30 according to the fourth embodiment of the present invention includes a multilayer printed wiring board 33 and a semiconductor chip 32 as a semiconductor element connected to the conductor film 5 as at least one of the conductor films 2 and 5. Prepare.
[0076]
According to the semiconductor device 30 configured as described above, the multilayer printed wiring board 33 electrically connected to the semiconductor chip 32 can exhibit the same effects as those described in the first embodiment.
[0077]
【Example】
Referring to FIG. 1, substrates 1 and 6 were formed from a glass epoxy substrate having a square shape of 340 mm × 340 mm. An adhesive 3 having a thickness T1 = T1a (adhesive 3a) + T1b (adhesive 3b), with the conductive film 2 having a thickness T3 = 18 μm and the conductive film 5 facing the conductive film 2 as electrodes, 784 capacitors each having a film-like dielectric film 4 having a thickness T2 as a dielectric film were formed in a matrix of every 10 mm in a range excluding the 30 mm area from the peripheral edges of the substrates 1 and 6. In order to obtain electrical connection with the conductor films 2 and 5, holes reaching the conductor films 2 and 5 were formed with a carbon dioxide laser processing machine, and chemical copper plating was performed on the holes.
[0078]
In addition to the carbon dioxide laser processing machine, a processing machine using another light source such as an excimer laser processing machine or a YAG laser processing machine can also be used. Further, instead of chemical copper plating, electrolytic copper plating can be performed, or a metal material or conductive resin other than copper can be used.
[0079]
By changing the values of the thickness T1 of the adhesive 3 and the thickness T2 of the film-like dielectric film 4, respectively, the printed wiring board of the products 1 to 4 of the present invention and the comparative product 1 for confirming the effect of the present invention 784 pieces of each of the four printed wiring boards were prepared. At this time, the printed wiring board was prepared by changing the thickness t1b of the adhesive 3b constituting the adhesive 3 before pressing. Then, the capacitance density of the capacitor built in the printed wiring board, the variation in capacitance, and the frequency of occurrence of a short circuit are obtained, the thickness t1b of the adhesive 3b before pressing, the thickness T2 of the film-like dielectric film 4, the electrode Table 1 shows the thickness T1 + T2 of the dielectric film between them and the ratio of the thickness of the adhesive 3 to the thickness of the dielectric film between the electrodes.
[0080]
[Table 1]

[0081]
The thickness T1 + T2 of the dielectric film between the electrodes was determined by measuring the thickness of the dielectric film at the peripheral and central portions of the conductor films 2 and 5, respectively, and averaging the measured values. In addition, the continuity between the electrodes was checked with a DC voltage tester of 1 (V) to check for short circuits. And in the capacitor | condenser which is not short-circuited, the capacitance density of a capacitor | condenser and the dispersion | variation in an electrostatic capacitance were evaluated.
[0082]
An impedance analyzer was connected to the conductor films 2 and 5, and the capacitance of each capacitor was measured using a signal having a measurement frequency of 1 (MHz) and an amplitude of 1 (V). Then, the capacitance value was divided by the areas of the conductor films 2 and 5 derived by X-ray transmission observation to determine the capacitance density of the capacitor. Table 1 shows the average value of the capacitance density of the capacitors thus obtained.
[0083]
In addition, the standard deviation is derived from the measured capacitance value of each capacitor, and the dispersion of the capacitance is obtained by dividing the value of three times the standard deviation by the average value of the capacitance of the capacitor. It was.
[0084]
Referring to Table 1, the printed wiring boards of Examples 1 to 3 were provided with a film-like dielectric film 4 having a thickness of 6 μm. On the other hand, the film-like dielectric film 4 was not provided on the printed wiring boards of the comparative products 1 to 3. As a result, in the printed wiring boards of Examples 1 to 3, it was possible to suppress the variation in capacitance, but in the printed wiring boards of Comparative products 1 and 2, the variation in capacitance was large. Further, in the printed wiring board of the comparative product 1 in which the thickness of the dielectric film was small, a short circuit occurred in 21 capacitors out of 784. From the above, it was confirmed that the provision of the film-like dielectric film 4 can prevent short-circuiting between electrodes and suppress variation in capacitance.
[0085]
In addition, in the printed wiring board of the comparative product 3, although the film-like dielectric film | membrane 4 was not provided, the dispersion | variation in an electrostatic capacitance was able to be suppressed. This is presumably because the thickness of the dielectric film was sufficiently large in the printed wiring board of the comparative product 3 and was not significantly affected by the unevenness on the substrate 1. However, the printed wiring board of Comparative Example 3 has a problem that the capacitance density of the capacitor is reduced, and the capacitor cannot be embedded in the printed wiring board at a high density.
[0086]
Further, in the printed wiring boards of Examples 1 to 3, the ratio of the thickness 3 of the adhesive 3 to the thickness T1 + T2 of the dielectric film is 0.4 or less, whereas in the printed wiring board of the comparative product 4, It exceeded 0.4 and was set to 0.60. As a result, the printed wiring board of the comparative product 4 could not sufficiently suppress the variation in the capacitance of the capacitor. Therefore, by setting the ratio of the thickness T1 of the adhesive 3 to the thickness T1 + T2 of the dielectric film within the range of 0 <T1 / (T1 + T2) ≦ 0.4, sufficient variation in the capacitance of the capacitor can be obtained. It was confirmed that it can be suppressed.
[0087]
Moreover, in the printed wiring board of the implementation product 4, the adhesive 3a that contacts the conductor film 5 was not provided as in the printed wiring board 20 shown in FIG. . However, even in this case, if the film-like dielectric film 4 is provided so as to be in close contact with the conductor film 5, variation in the capacitance of the capacitor can be sufficiently suppressed, and a short circuit between the electrodes can be achieved. It has been confirmed that a printed wiring board with a built-in capacitor can be realized.
[0088]
It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0089]
【The invention's effect】
As described above, according to the present invention, a printed wiring board having a built-in capacitor that is formed with a desired capacitance density without variation and can reliably prevent a short circuit between electrodes facing each other, and the printed wiring A semiconductor device including a board and a method for manufacturing the printed wiring board can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a printed wiring board according to Embodiment 1 of the present invention.
2 is a cross-sectional view showing a first step of the method of manufacturing the printed wiring board shown in FIG.
3 is a cross-sectional view showing a second step of the method of manufacturing the printed wiring board shown in FIG.
4 is a cross-sectional view showing a third step of the method of manufacturing the printed wiring board shown in FIG. 1. FIG.
FIG. 5 is a cross-sectional view showing a fourth step of the method of manufacturing the printed wiring board shown in FIG.
6 is a cross-sectional view showing a fifth step of the method of manufacturing the printed wiring board shown in FIG. 1. FIG.
7 is a cross-sectional view showing a sixth step of the method of manufacturing the printed wiring board shown in FIG. 1. FIG.
8 is a cross-sectional view showing a first step of a method of manufacturing a printed wiring board in the second embodiment. FIG.
9 is a cross-sectional view showing a second step of the method of manufacturing the printed wiring board in the second embodiment. FIG.
FIG. 10 is a cross-sectional view showing a printed wiring board according to Embodiment 3 of the present invention.
11 is a cross-sectional view showing a first step of the method of manufacturing the printed wiring board shown in FIG.
12 is a cross-sectional view showing a second step of the method of manufacturing the printed wiring board shown in FIG.
13 is a cross-sectional view showing a third step of the method of manufacturing the printed wiring board shown in FIG.
14 is a cross-sectional view showing a fourth step of the method of manufacturing the printed wiring board shown in FIG.
15 is a cross-sectional view showing a fifth step of the method of manufacturing the printed wiring board shown in FIG.
FIG. 16 is a cross sectional view showing a semiconductor device according to a fourth embodiment of the present invention.
[Explanation of symbols]
1,6 Substrate, 1a Main surface, 2,5 Conductor film, 3,3a, 3b Adhesive, 4 Film-like dielectric film, 10,20 Printed wiring board, 30 Semiconductor device, 32 Semiconductor chip, 33 Multilayer print Wiring board.

Claims (9)

First and second conductive films facing each other;
A first dielectric film provided between the first conductor film and the second conductor film and in contact with at least one of the first and second conductor films;
A second dielectric film provided between the first conductor film and the second conductor film, wherein the first dielectric film is in a solid state under conditions where the first dielectric film has fluidity. ,
A printed wiring board satisfying a relationship of 0 <T1 / (T1 + T2) ≦ 0.4, where T1 and T2 are the thicknesses of the first and second dielectric films. The substrate further includes a base material having a main surface on which the first conductor film protrudes, and the first dielectric film is provided so as to cover the first conductor film and the main surface. The printed wiring board according to claim 1. The printed wiring board according to claim 2, wherein the first dielectric film is provided in contact with only the first conductor film of the first and second conductor films. The first dielectric film includes at least one selected from the group consisting of epoxy resin, bismaleimide triazine resin, urethane resin, melamine resin, silicon resin, polyacrylic resin, urea resin, and phenol resin. The printed wiring board according to any one of 1 to 3. The second dielectric film is made of polyphenylene sulfide, polyphenylsulfone, polyimide, polyetherimide, polyphenyl oxide, polyamide, polycarbonate, liquid crystal polyester, polyester, polyvinyl chloride, polysilane, polyethyl ether ketone, acetate, and polypropylene. The printed wiring board of any one of Claim 1 to 4 containing at least 1 sort (s) chosen from the group. A semiconductor device comprising: the printed wiring board according to claim 1; and a semiconductor element connected to at least one of the first and second conductor films. A first dielectric film having fluidity and having a thickness of t1 between the first conductor film and the second conductor film; and a second dielectric film having a thickness of T2 in a solid state. Positioning the dielectric film;
Pressing the first and second conductive films until a thickness t1 of the first dielectric film reaches T1 satisfying a relationship of 0 <T1 / (T1 + T2) ≦ 0.4;
A method of manufacturing a printed wiring board, comprising: a step of curing the first dielectric film after the step of pressing. The first conductor film is provided on the main surface of the substrate and has a thickness of T3, and the first dielectric film is provided so as to cover the first conductor film and the main surface. The printed wiring board manufacturing method according to claim 7, wherein a thickness t1 of the first dielectric film before pressing satisfies a relationship of t1 <T3. The step of positioning the first and second dielectric films includes a step of forming a laminate in which the first and second dielectric films are laminated on the second conductor film; and The method for producing a printed wiring board according to claim 7, further comprising a step of laminating the first conductor film.

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