JP2006147967A

JP2006147967A - Circuit board and its manufacturing method

Info

Publication number: JP2006147967A
Application number: JP2004338396A
Authority: JP
Inventors: Hiroyuki Yamanaka; 浩之山仲
Original assignee: Shin Kobe Electric Machinery Co Ltd
Current assignee: Resonac Corp
Priority date: 2004-11-24
Filing date: 2004-11-24
Publication date: 2006-06-08

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit board capable of suppressing a whitening phenomenon and separation of a synthetic resin board to occur when a press-fit terminal is inserted thereinto. <P>SOLUTION: Two contact points 15e of a press-fit contact 15b are pressed to the inner face of the cylindrical conductive part 7c of a through hole conductive part 7 by a spring force, so that a press-fit terminal 15 is connected to the through hole conductive part 7. The press-fit contact 15b is press-fitted into the through hole conductive part 7 so that the two contact points 15e of the press-fit contact 15b are arranged in a direction D1 that a warp thread 5a having a more number per unit length extends out of a warp thread and a cross thread which constitute a glass cloth 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、回路基板及びその製造方法に関するものであり、特にプレスフィット端子を用いる回路基板及びその製造方法に関するものである。 The present invention relates to a circuit board and a manufacturing method thereof, and particularly to a circuit board using a press-fit terminal and a manufacturing method thereof.

回路基板に搭載される部品、コネクタ等は、通常、半田付けによりプリント配線基板の配線パターンに接続されている。しかしながら、最近では環境に関する規制の中で鉛フリーの要求が高まっており、プリント配線基板への部品の実装に使用される半田についても鉛フリー化の対象となっている。実装部品には表面実装部品とスルーホールに挿入する挿入部品とがあり、表面実装を行う際のリフロー工程における半田においては、鉛フリー半田が主流となってきている。しかしながら、コネクタ等の挿入部品実装時のスポットフローでは、コスト面から鉛フリー半田を使用することがほとんど無く、鉛入りの半田を使用していた。そこで、最近では、半田を使用する技術に代わり、半田を使用しないで圧入だけで接続をするプレスフィット工法により部品、コネクタ等を接続した回路基板が、民生機器などにおいて既に実施され、車載用途部品に関しても一部使用されている。 Components, connectors and the like mounted on the circuit board are usually connected to the wiring pattern of the printed wiring board by soldering. However, recently, the demand for lead-free has been increasing in environmental regulations, and solder used for mounting components on a printed wiring board is also subject to lead-free. There are two types of mounting components: surface mounting components and insertion components that are inserted into through-holes. Lead-free solder has become the mainstream of solder in the reflow process when performing surface mounting. However, in the spot flow when mounting an insertion component such as a connector, lead-free solder is rarely used from the viewpoint of cost, and lead-containing solder is used. Therefore, recently, circuit boards with parts, connectors, etc. connected by the press-fit method of connecting by press-fitting without using solder instead of using solder have already been implemented in consumer devices. Some are also used.

例えば、特開平１０−２０８７９８号公報（特許文献１）の図２には、筒状導電部を備えたスルーホール導電部が形成されたプリント配線基板に対して、プレスフィット端子の圧入接触部をスルーホール導電部の筒状導電部内に圧入することにより、プレスフィット端子をプリント配線基板に対して接続している。圧入接触部は、筒状導電部の内径よりわずかに大きい幅寸法を有し、中央に貫通孔を有する平板部により構成されている。この構造により、圧入接触部の筒状導電部の径方向に延びる方向の両端部は、筒状導電部の内面にバネ力により強く押しつけられている。 For example, in FIG. 2 of Japanese Patent Laid-Open No. 10-208798 (Patent Document 1), a press-fit terminal press-fit contact portion is formed on a printed wiring board on which a through-hole conductive portion having a cylindrical conductive portion is formed. The press-fit terminal is connected to the printed wiring board by press-fitting into the cylindrical conductive portion of the through-hole conductive portion. The press-fit contact portion has a width dimension slightly larger than the inner diameter of the cylindrical conductive portion, and is configured by a flat plate portion having a through hole in the center. With this structure, both ends of the press-fitting contact portion in the direction extending in the radial direction of the cylindrical conductive portion are strongly pressed against the inner surface of the cylindrical conductive portion by a spring force.

特開平１０−２０８７９８号公報Japanese Patent Laid-Open No. 10-208798

しかしながら、プリント配線基板のスルーホール導電部にプレスフィット端子を挿入すると、合成樹脂基板の圧入接触部に押された部分が損傷を受けて合成樹脂基板に白化現象が発生し、ガラス繊維と樹脂との間で剥離が発生する。図５は、プレスフィット端子が接続された回路基板において、ランド部をエッチングにより除去した後のスルーホール導電部の周囲のプリント配線基板の断面の顕微鏡写真である。本写真に示すように、プレスフィット端子が接続された回路基板では、白化現象Ｗが発生しているのが確認できる。このような白化現象に基づく剥離が発生すると、車載用途のような厳しい環境下においては、剥離部分に水分が溜まりマイグレーションの発生原因となる。このような問題に対して、半田レベラーによる応力緩和やスルーホール径の公差を厳しくすることも考えられる。しかしながら、半田レベラーによる応力緩和では鉛フリー化に逆行する。また、スルーホール公差を厳しくすれば歩留まりが悪くなる。 However, when a press-fit terminal is inserted into the through-hole conductive part of the printed wiring board, the portion pressed by the press-fitting contact part of the synthetic resin substrate is damaged and a whitening phenomenon occurs in the synthetic resin substrate. Peeling occurs between the two. FIG. 5 is a micrograph of a cross section of the printed wiring board around the through-hole conductive portion after the land portion is removed by etching in the circuit board to which the press-fit terminals are connected. As shown in this photograph, it can be confirmed that the whitening phenomenon W occurs in the circuit board to which the press-fit terminals are connected. When peeling based on such a whitening phenomenon occurs, in a severe environment such as in-vehicle use, moisture accumulates in the peeling portion and causes migration. For such problems, it is conceivable to relieve stress due to the solder leveler and tighten the tolerance of the through hole diameter. However, stress relaxation by solder levelers goes against lead-free. Further, if the through-hole tolerance is tightened, the yield is deteriorated.

本発明の目的は、プレスフィット端子を挿入する際に発生する合成樹脂基板の白化現象及び剥離を抑制できる回路基板及びその製造方法を提供することにある。 The objective of this invention is providing the circuit board which can suppress the whitening phenomenon and peeling of a synthetic resin board | substrate which generate | occur | produce when inserting a press fit terminal, and its manufacturing method.

本発明が改良の対象とする回路基板は、補強用織布に合成樹脂が含浸されてなる合成樹脂基板の少なくと一方の面上に配線パターンが形成され、合成樹脂基板を厚み方向に貫通するようにスルーホールが形成され、スルーホールの内面上に配線パターンと電気的に接続された筒状導電部を備えたスルーホール導電部が形成されたプリント配線基板を備えている。そして、プリント配線基板の筒状導電部内に、対向する２つの接点部を有する圧入接触部を先端部に備えたプレスフィット端子の圧入接触部が圧入されて、圧入接触部の２つの接点部が筒状導電部の内面に押しつけられている。ここでいう「プリント配線基板」とは、内部に配線パターンを有しない回路基板及び多層回路基板の両方を含むものである。また、プリント配線基板に形成される「スルーホール導電部」には、プリント配線基板の配線パターンと電気的に接続されておらず、あくまでも端子の固定のためだけに設けられるいわゆるダミースルーホール導電部が含まれてよいのは勿論である。 The circuit board to be improved by the present invention has a wiring pattern formed on at least one surface of a synthetic resin board in which a reinforcing woven fabric is impregnated with a synthetic resin, and penetrates the synthetic resin board in the thickness direction. Through-holes are formed as described above, and a printed wiring board having a through-hole conductive portion including a cylindrical conductive portion electrically connected to the wiring pattern on the inner surface of the through-hole is provided. Then, a press-fit contact portion of a press-fit terminal provided with a press-fit contact portion having two contact portions facing each other in the cylindrical conductive portion of the printed wiring board is press-fitted, and the two contact portions of the press-fit contact portion are It is pressed against the inner surface of the cylindrical conductive part. The “printed wiring board” here includes both a circuit board having no wiring pattern therein and a multilayer circuit board. In addition, the “through-hole conductive part” formed on the printed wiring board is not electrically connected to the wiring pattern of the printed wiring board, and is a so-called dummy through-hole conductive part provided only for fixing the terminal. Of course, may be included.

本発明では、圧入接触部の２つの接点部が、補強用織布を構成する縦糸と横糸の内、単位長さあたりの本数が多くなる方の糸が延びている方向に並ぶように、圧入接触部をスルーホール導電部内に圧入する。本発明のように、圧入接触部の２つの接点部が、補強用織布を構成する縦糸と横糸の内、単位長さあたりの本数が多くなる方の糸が延びている方向に並ぶように、圧入接触部をスルーホール導電部内に圧入すると、圧入接触部の２つの接点部が接触する部分のプリント配線基板の近傍は、補強用織布を構成する糸の量が多く、白化現象や剥離が生じる合成樹脂の量は少ない。そのため、プレスフィット端子がスルーホール導電部内に挿入されても、合成樹脂基板に白化現象や剥離が生じるのを抑制することができる。 In the present invention, the two contact portions of the press-fit contact portion are press-fitted so that the warp yarn and the weft yarn constituting the reinforcing woven fabric are aligned in the direction in which the yarn having the larger number per unit length extends. The contact portion is press-fitted into the through-hole conductive portion. As in the present invention, the two contact portions of the press-fitting contact portion are arranged in a direction in which the yarn having the larger number per unit length of the warp yarn and the weft yarn constituting the reinforcing woven fabric extends. When the press-fit contact portion is press-fitted into the through-hole conductive portion, the portion of the press-contact contact portion where the two contact portions are in contact with each other in the vicinity of the printed wiring board has a large amount of yarn constituting the reinforcing woven fabric, and whitening phenomenon or peeling The amount of synthetic resin that produces is small. Therefore, even if the press-fit terminal is inserted into the through-hole conductive portion, it is possible to suppress the whitening phenomenon and the peeling from occurring on the synthetic resin substrate.

合成樹脂基板の表面には、単位長さあたりの本数が多くなる方の糸が延びている方向を示す印を表示するのが好ましい。このようにすれば、印を目印にして、プレスフィット端子をスルーホール導電部内に挿入することにより、圧入接触部の２つの接点部を、補強用織布を構成する縦糸と横糸の内、単位長さあたりの本数が多くなる方の糸が延びている方向に確実に並べることができる。 It is preferable to display on the surface of the synthetic resin substrate a mark indicating the direction in which the yarn having a larger number per unit length extends. If it does in this way, by using a mark as a mark and inserting a press-fit terminal into a through-hole conductive part, the two contact parts of a press-fit contact part are unit of warp and weft constituting a reinforcing woven fabric. The yarns with the larger number per length can be reliably arranged in the extending direction.

本発明が改良の対象とする回路基板の製造方法は、補強用織布に合成樹脂が含浸されてなる合成樹脂基板の少なくと一方の面上に配線パターンが形成され、合成樹脂基板を厚み方向に貫通するようにスルーホールが形成され、スルーホールの内面上に配線パターンと電気的に接続される筒状導電部を備えたスルーホール導電部が形成されたプリント配線基板の筒状導電部内に、対向する２つの接点部を有する圧入接触部を先端部に備えたプレスフィット端子の圧入接触部を圧入し、圧入接触部の２つの接点部を筒状導電部の内面に押しつける。本発明では、圧入接触部の２つの接点部が、補強用織布を構成する縦糸と横糸の内、単位長さあたりの本数が多くなる方の糸が延びている方向に並ぶように、圧入接触部をスルーホール導電部内に圧入する。本発明の方法でプリント配線基板を製造すれば、プレスフィット端子がスルーホール導電部内に挿入されても、合成樹脂基板に白化現象や剥離が生じるのを抑制することができる。 The method for manufacturing a circuit board to be improved by the present invention is such that a wiring pattern is formed on at least one surface of a synthetic resin substrate in which a reinforcing woven fabric is impregnated with a synthetic resin, and the synthetic resin substrate is formed in the thickness direction. In the cylindrical conductive part of the printed wiring board in which a through hole is formed so as to penetrate through and a through hole conductive part having a cylindrical conductive part electrically connected to the wiring pattern is formed on the inner surface of the through hole. The press-fit contact portion of a press-fit terminal having a press-fit contact portion having two contact portions facing each other is pressed into the tip portion, and the two contact portions of the press-fit contact portion are pressed against the inner surface of the cylindrical conductive portion. In the present invention, the two contact portions of the press-fit contact portion are press-fitted so that the warp yarn and the weft yarn constituting the reinforcing woven fabric are aligned in the direction in which the yarn having the larger number per unit length extends. The contact portion is press-fitted into the through-hole conductive portion. If a printed wiring board is manufactured by the method of the present invention, even if a press-fit terminal is inserted into a through-hole conductive part, it is possible to suppress the occurrence of whitening or peeling on the synthetic resin substrate.

本発明によれば、圧入接触部の２つの接点部が、補強用織布を構成する縦糸と横糸の内、単位長さあたりの本数が多くなる方の糸が延びている方向に並ぶように、圧入接触部をスルーホール導電部内に圧入するので、プレスフィット端子がスルーホール導電部内に挿入されても、合成樹脂基板に白化現象や剥離が生じるのを抑制することができる。 According to the present invention, the two contact portions of the press-fit contact portion are arranged in a direction in which the yarn having the larger number per unit length of the warp and weft constituting the reinforcing woven fabric extends. Since the press-fitting contact portion is press-fitted into the through-hole conductive portion, it is possible to suppress the occurrence of whitening or peeling on the synthetic resin substrate even if the press-fit terminal is inserted into the through-hole conductive portion.

以下、図面を参照して本発明の回路基板の実施の形態を詳細に説明する。図１は、プレスフィット端子を接続する前の本発明の一実施の形態の回路基板の斜視図であり、図２は、図１の部分拡大図である。両図に示すように、本例の回路基板は、プリント配線基板１と電気部品３とから構成されている。プリント配線基板１は、補強用織布を構成するガラスクロス５にエポキシ樹脂からなる合成樹脂を含浸したプリプレグ８枚を積層し、加圧加熱状態で一体化した板厚１．６mmの汎用ＦＲ−４両面板の合成樹脂基板２を備えている。合成樹脂は、プリプレグに対して４０重量％含浸されている。合成樹脂基板２の表面２ａ及び裏面２ｂには、銅箔等の導電性材料からなる図示しない所定の配線パターンが形成されている。ガラスクロス５は、図２において破線で概略的に示すように、基準厚２００μｍのガラス繊維で４４本／２５mmの密度の縦糸５ａと３３本／２５mmの密度の横糸５ｂとを構成するように織り込んだ旭シュエーベル株式会社製の「Ｇ７６２８（製品番号）」を使用した。
プリント配線基板１の縁部には、７つのスルーホール導電部７が並んで形成されている。そして、合成樹脂基板２の表面２ａには、単位長さあたりの本数が多くなる方の糸が延びている方向を示す印８が表示されている。本例では、縦糸５ａが横糸５ｂより単位長さあたりの本数が多いので、印８は、縦糸５ａが延びる方向Ｄ１に沿う矢印の形状を有している。 Embodiments of a circuit board according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of a circuit board according to an embodiment of the present invention before connecting a press-fit terminal, and FIG. 2 is a partially enlarged view of FIG. As shown in both figures, the circuit board of this example is composed of a printed wiring board 1 and an electrical component 3. The printed wiring board 1 is a general-purpose FR- having a thickness of 1.6 mm, in which eight prepregs impregnated with a synthetic resin made of epoxy resin are laminated on a glass cloth 5 constituting a reinforcing woven cloth and integrated in a pressurized state. A four-sided synthetic resin substrate 2 is provided. The synthetic resin is impregnated with 40% by weight with respect to the prepreg. A predetermined wiring pattern (not shown) made of a conductive material such as copper foil is formed on the front surface 2 a and the back surface 2 b of the synthetic resin substrate 2. The glass cloth 5 is woven so as to form warps 5a having a density of 44/25 mm and wefts 5b having a density of 33/25 mm and glass fibers having a reference thickness of 200 μm, as schematically shown by a broken line in FIG. “G7628 (product number)” manufactured by Asahi Schubel Co., Ltd. was used.
Seven through-hole conductive portions 7 are formed side by side at the edge of the printed wiring board 1. On the surface 2a of the synthetic resin substrate 2, a mark 8 indicating the direction in which the thread having a larger number per unit length extends is displayed. In this example, since the number of warp yarns 5a per unit length is greater than that of the weft yarns 5b, the mark 8 has an arrow shape along the direction D1 in which the warp yarns 5a extend.

スルーホール導電部７は、銅メッキにより形成されており、図３に示すように、合成樹脂基板２を厚み方向に貫通する横断面形状がほぼ円形のスルーホール２ｃの開口部の周囲と内面上に形成されている。スルーホール導電部７は、合成樹脂基板２の表面２ａ及び裏面２ｂに、スルーホール２ｃの開口部に沿ってそれぞれ形成された環状のランド部７ａ，７ｂと貫通孔１ａ内に配置された筒状導電部７ｃとを一体に有している。本例では、メッキにより平均２５μｍの厚みになるようにスルーホール導電部７を形成した。環状のランド部７ａ，７ｂの全部またはいくつかは、合成樹脂基板２上の図示しない配線パターンの所定部分と電気的に接続されている。 The through-hole conductive portion 7 is formed by copper plating, and as shown in FIG. 3, the periphery of the through-hole 2 c and the inner surface of the through-hole 2 c having a substantially circular cross section passing through the synthetic resin substrate 2 in the thickness direction. Is formed. The through-hole conductive portion 7 is a cylindrical shape disposed in the through-hole 1a and the annular land portions 7a and 7b formed on the front surface 2a and the back surface 2b of the synthetic resin substrate 2 along the opening of the through-hole 2c. The conductive portion 7c is integrally provided. In this example, the through-hole conductive portion 7 was formed by plating so as to have an average thickness of 25 μm. All or some of the annular land portions 7a and 7b are electrically connected to predetermined portions of a wiring pattern (not shown) on the synthetic resin substrate 2.

電気部品３は、本体部９と７つの接続端子１１とを有するいわゆる多極コネクタである。接続端子１１は、Ｌ字形を有しており、本体部９から延び出る基部１３と、基部１３に対してほぼ直角に曲げられた先端部分を構成するプレスフィット端子部１５とから構成されている。プレスフィット端子部１５は、図３に示すように、接続端子１１を形成するための金属板を打ち抜き加工する際に同時に形成されており、長手方向に延びる板状の中央部１５ａと圧入接触部１５ｂと一対の突出部１５ｃとを有している。圧入接触部１５ｂは、長手方向と直交する方向に中央部１５ａから相互に離れるように突出する一対の接触片１５ｈを有している。この接触片１５ｈは、先端側から基部１３側に向かうにしたがって中央部１５ａから徐々に離れるように傾斜する前方端面１５ｄと、中央部１５ａと平行に延びる側面１５ｅと、先端側から基部１３側に向かうにしたがって中央部１５ａに徐々に近づくように傾斜する後方端面１５ｆとを有している。一対の接触片１５ｈのそれぞれの側面１５ｅを結ぶ距離は、スルーホール導電部７の内径（１．０mm）をわずかに上回る寸法（１．２５mm）を有している。また、中央部１５ａの一対の一対の接触片１５ｈに挟まれた中央部分には、中央部１５ａの長手方向に延びて該中央部１５ａを厚み方向に貫通する楕円形の孔部１５ｇが形成されている。そして、図４に示すように、プレスフィット端子部１５がスルーホール導電部７内に挿入された状態では、圧入接触部１５ｂの一対の側面（２つの接点部）１５ｅは、筒状導電部７ｃの内面に押しつけられている。また、圧入接触部１５ｂは、該圧入接触部１５ｂの２つの接点部１５ｅが、ガラスクロス５を構成する縦糸と横糸の内、単位長さあたりの本数が多くなる方の糸（縦糸５ａ）が延びている方向Ｄ１に並ぶように、スルーホール導電部７内に圧入されている。なお、図２には、プレスフィット端子部１５がスルーホール導電部７内に挿入された状態の一対の接触片１５ｈを併せて描いている。 The electrical component 3 is a so-called multipolar connector having a main body portion 9 and seven connection terminals 11. The connection terminal 11 has an L-shape, and is composed of a base portion 13 extending from the main body portion 9 and a press-fit terminal portion 15 constituting a tip portion bent substantially at a right angle with respect to the base portion 13. . As shown in FIG. 3, the press-fit terminal portion 15 is formed at the same time as punching a metal plate for forming the connection terminal 11, and has a plate-like central portion 15 a extending in the longitudinal direction and a press-fit contact portion. 15b and a pair of protrusions 15c. The press-fit contact portion 15b has a pair of contact pieces 15h that protrude away from the center portion 15a in a direction orthogonal to the longitudinal direction. The contact piece 15h includes a front end surface 15d that is inclined so as to gradually move away from the central portion 15a from the distal end side toward the base portion 13 side, a side surface 15e that extends parallel to the central portion 15a, and a distal end side toward the base 13 side. The rear end face 15f is inclined so as to gradually approach the central portion 15a as it goes. The distance connecting the side surfaces 15e of the pair of contact pieces 15h has a dimension (1.25 mm) slightly exceeding the inner diameter (1.0 mm) of the through-hole conductive portion 7. Further, an elliptical hole portion 15g extending in the longitudinal direction of the central portion 15a and penetrating through the central portion 15a in the thickness direction is formed in the central portion sandwiched between the pair of contact pieces 15h of the central portion 15a. ing. As shown in FIG. 4, in a state where the press-fit terminal portion 15 is inserted into the through-hole conductive portion 7, the pair of side surfaces (two contact portions) 15e of the press-fit contact portion 15b are formed as the cylindrical conductive portion 7c. It is pressed against the inner surface. Further, the press-fit contact portion 15b has two contact portions 15e of the press-fit contact portion 15b, and the warp yarn and the weft yarn constituting the glass cloth 5 have a larger number of yarns per unit length (warp yarn 5a). The through-hole conductive portion 7 is press-fitted so as to be aligned in the extending direction D1. In FIG. 2, a pair of contact pieces 15 h in a state where the press-fit terminal portion 15 is inserted into the through-hole conductive portion 7 is also illustrated.

一対の突出部１５ｃは、圧入接触部１５ｂよりも基部１３側に離れた位置にあって、中央部１５ａから相互に離れるように突出しており、それぞれの先端間の距離は、スルーホール導電部７の内径（１．０mm）を大きく上回る寸法を有している。 The pair of projecting portions 15c are located farther toward the base portion 13 than the press-fit contact portion 15b, and project so as to be separated from the central portion 15a. It has dimensions that greatly exceed the inner diameter (1.0 mm).

本例では、合成樹脂基板２の表面２ａ側から図３の矢印Ａに示す方向に、プレスフィット端子部１５をスルーホール導電部７内に圧入して、図４に示すようにプレスフィット端子部１５とスルーホール導電部７とを接続して、プリント配線基板１にプレスフィット電気部品３を実装する。両者が接続された状態において、プレスフィット端子部１５の一対の肩部１５ｃとランド部７ａの表面とが当接する。また、プレスフィット端子部１５の圧入接触部１５ｂは、その接点部１５ｅがスルーホール導電部７の筒状導電部７ｃ内に当接した状態で、スルーホール導電部７の径方向に圧縮される。これにより、圧入接触部１５ｂの接点部１５ｅをスルーホール導電部７の筒状導電部７ｃの内面にバネ力により押しつける。本例の回路基板では、圧入接触部１５ｂの２つの接点部１５ｅが、ガラスクロス５を構成する縦糸と横糸の内、単位長さあたりの本数が多くなる方の糸（縦糸５ａ）が延びている方向Ｄ１に並ぶように、圧入接触部１５ｂがスルーホール導電部７内に圧入されているので、２つの接点部１５ｅが接触する部分のプリント配線基板の近傍は、ガラスクロス５の繊維の量が多く、白化現象や剥離が生じる合成樹脂の量は少ない。そのため、プレスフィット端子部１５がスルーホール導電部７内に挿入されても、合成樹脂基板２に白化現象や剥離が生じるのを抑制することができる。 In this example, the press-fit terminal portion 15 is press-fitted into the through-hole conductive portion 7 in the direction indicated by the arrow A in FIG. 3 from the surface 2a side of the synthetic resin substrate 2, and as shown in FIG. 15 and the through-hole conductive portion 7 are connected, and the press-fit electrical component 3 is mounted on the printed wiring board 1. In a state where both are connected, the pair of shoulder portions 15c of the press-fit terminal portion 15 and the surface of the land portion 7a come into contact with each other. The press-fit contact portion 15b of the press-fit terminal portion 15 is compressed in the radial direction of the through-hole conductive portion 7 with the contact portion 15e in contact with the cylindrical conductive portion 7c of the through-hole conductive portion 7. . Thereby, the contact portion 15e of the press-fit contact portion 15b is pressed against the inner surface of the cylindrical conductive portion 7c of the through-hole conductive portion 7 by a spring force. In the circuit board of this example, the two contact portions 15e of the press-fitting contact portion 15b are extended by the yarn (warp yarn 5a) having a larger number per unit length among the warp yarn and the weft yarn constituting the glass cloth 5. Since the press-fit contact portion 15b is press-fitted into the through-hole conductive portion 7 so as to be aligned in the direction D1, the vicinity of the printed wiring board where the two contact portions 15e are in contact is the amount of fiber of the glass cloth 5 The amount of synthetic resin that causes whitening and peeling is small. Therefore, even if the press-fit terminal portion 15 is inserted into the through-hole conductive portion 7, it is possible to suppress the whitening phenomenon and the peeling from occurring on the synthetic resin substrate 2.

次に、本例の回路基板（実施例）１０個と、比較例の回路基板１０個のプレスフィット端子部１５の挿入による白化現象の発生部分の平均長さ（図５に示す長さ寸法Ｌ）を測定した。比較例の回路基板では、圧入接触部１５ｂの２つの接点部１５ｅが、ガラスクロス５を構成する縦糸と横糸の内、単位長さあたりの本数が少なくなる方の糸（横糸５ｂ）が延びている方向Ｄ２に並ぶように、圧入接触部１５ｂをスルーホール導電部７内に圧入したものである。表１は、その結果を示している。 Next, the average length of the portion where the whitening phenomenon occurs due to insertion of 10 circuit boards (examples) of this example and 10 press-fit terminal portions 15 of the comparative example (the length dimension L shown in FIG. 5). ) Was measured. In the circuit board of the comparative example, the two contact portions 15e of the press-fitting contact portion 15b are extended by a yarn (weft yarn 5b) having a smaller number per unit length of the warp yarn and the weft yarn constituting the glass cloth 5. The press-fit contact portion 15b is press-fitted into the through-hole conductive portion 7 so as to line up in the direction D2. Table 1 shows the results.

表１より、実施例の回路基板は、比較例の回路基板に比べて白化現象の発生部分の平均長さが短いのが分かる。 From Table 1, it can be seen that the circuit board of the example has a shorter average length of the whitening occurrence portion than the circuit board of the comparative example.

プレスフィット端子を接続する前の本発明の実施の形態の回路基板の斜視図である。It is a perspective view of a circuit board of an embodiment of the invention before connecting a press fit terminal. 図１の部分拡大図である。It is the elements on larger scale of FIG. 図１に示す回路基板を説明するために用いる端子接続前の回路基板のプリント配線基板及びプレスフィット端子の断面図である。It is sectional drawing of the printed wiring board and press-fit terminal of the circuit board before the terminal connection used in order to demonstrate the circuit board shown in FIG. 本発明の実施の形態の回路基板を説明するために用いる端子接続後の回路基板のプリント配線基板及びプレスフィット端子の断面図である。It is sectional drawing of the printed wiring board and press-fit terminal of the circuit board after the terminal connection used in order to demonstrate the circuit board of embodiment of this invention. 従来の回路基板において、ランド部をエッチングにより除去した後のスルーホール導電部の周囲の断面の顕微鏡写真である。In the conventional circuit board, it is a microscope picture of the cross section around the through-hole conductive part after removing the land part by etching.

Explanation of symbols

１プリント配線基板
３電気部品
５ガラスクロス（補強用織布）
５ａ縦糸
５ｂ横糸
７スルーホール導電部
７ｃ筒状導電部
１５プレスフィット端子部
１５ｂ圧入接触部
１５ｅ側面（接点部） 1 Printed circuit board 3 Electrical parts 5 Glass cloth (woven cloth for reinforcement)
5a Warp 5b Weft 7 Through-hole conductive part 7c Cylindrical conductive part 15 Press-fit terminal part 15b Press-fit contact part 15e Side (contact part)

Claims

A wiring pattern is formed on at least one surface of a synthetic resin substrate in which a reinforcing woven fabric is impregnated with a synthetic resin, and a through hole is formed so as to penetrate the synthetic resin substrate in the thickness direction. A press-fitting having two contact portions facing each other in the cylindrical conductive portion of the printed wiring board in which a through-hole conductive portion having a cylindrical conductive portion electrically connected to the wiring pattern is formed on the inner surface of the printed wiring board In the circuit board in which the press-fit contact portion of the press-fit terminal having a contact portion at the tip portion is press-fitted, and the two contact portions of the press-fit contact portion are pressed against the inner surface of the cylindrical conductive portion,
The press-fitting is performed so that the two contact portions of the press-fitting contact portion are aligned in a direction in which the yarn having the larger number per unit length of warp yarns and weft yarns constituting the reinforcing woven fabric extends. A circuit board, wherein a contact portion is press-fitted into the through-hole conductive portion.

2. The circuit board according to claim 1, wherein a mark indicating a direction in which a yarn having a larger number per unit length extends is displayed on a surface of the synthetic resin substrate.

A wiring pattern is formed on at least one surface of a synthetic resin substrate in which a reinforcing woven fabric is impregnated with a synthetic resin, and a through hole is formed so as to penetrate the synthetic resin substrate in the thickness direction. Press-fit contact having two contact portions facing each other in the cylindrical conductive portion of the printed wiring board in which a through-hole conductive portion having a cylindrical conductive portion electrically connected to the wiring pattern is formed on the inner surface of the printed circuit board A method of manufacturing a circuit board, wherein the press-fit contact portion of a press-fit terminal provided with a tip portion is press-fitted, and the two contact portions of the press-fit contact portion are pressed against an inner surface of the cylindrical conductive portion,
The press-fitting is performed so that the two contact portions of the press-fitting contact portion are aligned in a direction in which the yarn having the larger number per unit length of warp yarns and weft yarns constituting the reinforcing woven fabric extends. A method for manufacturing a circuit board, comprising pressing a contact portion into the through-hole conductive portion.