JP2004007252A

JP2004007252A - Thin highly-stabilized piezo-oscillator and conductive connecting member

Info

Publication number: JP2004007252A
Application number: JP2002160367A
Authority: JP
Inventors: Tomio Sato; 佐藤　富雄
Original assignee: Toyo Communication Equipment Co Ltd
Current assignee: Toyo Communication Equipment Co Ltd
Priority date: 2002-05-31
Filing date: 2002-05-31
Publication date: 2004-01-08
Anticipated expiration: 2022-05-31
Also published as: JP4042471B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin highly-stabilized piezo-oscillator which simultaneously realizes increase in heating efficiency by adhering a piezoelectric vibrator to a heater closely despite of fitting the piezoelectric vibrator in a cutout formed in a second printed circuit board, a construction which keeps the piezoelectric vibrator warm efficiently by the second printed circuit board by arranging the piezoelectric vibrator closely to the second printed circuit board, and thinning close to its limit of a thickness ≤ 7.5 mm in addition. <P>SOLUTION: The piezo-oscillator is provided with the second printed circuit board 4 put on a first printed circuit board 2 with lead pins 3 in between, the piezoelectric vibrator 5, the heater 6, etc. mounted on the second printed circuit board. With the piezoelectric vibrator 5 and the heater 6 adhered closely via a conductive connecting member 15, the piezoelectric vibrator 5 and the heater 6 are fitted and supported in the recessed cutout 11 formed in the second printed circuit board. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、周波数制御デバイス等として使用される圧電発振器に関し、特に圧電振動子をヒータにより加熱するとともに、温度制御回路によってヒータ温度を制御する構成を備えながらも薄型化を可能とした圧電発振器、及び導電接続部材に関する。
【０００２】
【従来の技術】
移動体通信機器や伝送通信機器に用いる周波数制御デバイスである水晶発振器等の圧電発振器として、外部の温度変化に影響されることなく高安定な周波数を出力することができる恒温槽型圧電発振器が知られている。
更に、近年これらの分野では、各種機器に対して、小型、軽量で携帯可能であることが求められてきているため、それに対応して恒温槽型圧電発振器についても小型、軽量化が市場から求められている。
即ち、従来の恒温槽型圧電発振器の高さ寸法は、通常２０ｍｍ以上であり、場合によっては５０ｍｍ程度の高さ寸法まで大型化されたタイプも多用されてきた。しかし、近年、各種機器の小型化に対応して、恒温槽型圧電発振器についても他の大型部品と同等の高さ寸法まで低背化することが強く求められている。
ところで、従来の恒温槽型圧電発振器は、高安定な周波数を得るために、熱容量が大きい金属ブロック等の恒温槽（ｏｖｅｎ）の凹所内に圧電振動子を収容し、更に金属ブロックをヒータにより所定の温度に加熱していた。しかし、恒温槽として大型の金属ブロックを用いると、発振器全体の嵩が増大するため、小型、軽量化という要請を満たすことができなかった。また、金属ブロックを介して圧電振動子内部の圧電振動素子を加熱する構成であったため、ヒータからの熱が圧電振動素子に達して所定周波数に達するまでに長い時間を要するという問題があった。
このような従来の恒温槽型圧電発振器にあっては、金属ブロックを使用しているため、どのように工夫を凝らして薄型化を図ったとしても、発振器全体の高さ寸法を、９．２ｍｍとするのが限界であり、それ以下に抑えることは困難であった。
【０００３】
このような所から図９の断面図に示した如く、金属ブロックを使用せずにヒータを用いて圧電振動子を加熱する構成を備えた表面実装型の薄型高安定圧電発振器が提案されている。この薄型高安定圧電発振器（以下、圧電発振器、という）１００は、表面実装用の外部電極１０１ａを底部に備えた第１のプリント基板１０１と、第１のプリント基板１０１上の配線パターン（外部電極と導通）から立設されたリードピン１０２と、リードピン１０２の上部に接続固定され且つ該リードピンと導通する配線パターンを備えた第２のプリント基板１０３と、第２のプリント基板１０３底面の配線パターンにリード端子１０５ｂを接続することにより第２のプリント基板下面側に位置決めされた圧電振動子１０５と、圧電振動子１０５の缶ケース１０５ａが対面する第２のプリント基板下面の配線パターン上に電極部を接続配置されたセラミックヒータ１０６と、第２のプリント基板１０３上に搭載された回路部品（発振回路部品、温度コントロール回路部品等）１０７と、第１のプリント基板１０１上の各部品を含む空間を包囲するために第１のプリント基板上に固定された金属ケース１０８と、を備えている。
この圧電発振器１００にあっては、圧電振動子１０５を支持する第２のプリント基板１０３を金属ケース内空間のほぼ中央に浮いた状態で配置し、第１のプリント基板１０１及び缶ケース１０５ａとの熱的結合が粗になるように構成している。また、圧電振動子１０５を第２のプリント基板１０３の下面（或いは上面）に近接させて配置することにより可能な限り薄型化を図っているが、金属ケース１０８の高さは、第２のプリント基板１０３自体の肉厚、圧電振動子１０５、ヒータ１０６、回路部品１０７の厚さを全て加味して設定することになるため、薄型化には限界があった。
即ち、例えば、第１及び第２のプリント基板１０１、１０３の厚さを夫々１ｍｍ、圧電振動子１０５の厚さを３．２ｍｍ、セラミックヒータ１０６の厚さを０．５ｍｍ、圧電振動子及び第２のプリント基板と金属ケース１０８の内壁との間の間隔を夫々約１ｍｍ以上、金属ケース１０８の肉厚を０．２ｍｍとすれば、この圧電発振器１００の高さとしては７．７ｍｍが限界であり、高さ７．５ｍｍ以下という更なる低背化の要求に応えることはできない。
【０００４】
次に、図１０はヒータを備えない通常タイプの圧電発振器における薄型化対策を説明する図であり、圧電振動子１１１を、回路部品１１２を搭載したプリント基板１１０（第２のプリント基板）上に搭載する際にプリント基板１１０の一部を切欠き、この切欠き内に圧電振動子１１１の金属ケース１１１ａを落し込んで配置し、リード端子１１１ｂをプリント基板１１０上の配線パターン上に半田接続している。このように構成することにより、プリント基板の肉厚分だけ、圧電発振器の高さ方向寸法を薄型化することができるが、このような薄型化のための構造を図９に示した如き高安定圧電発振器１００に対して適用することは困難であるとされていた。
後述するように本発明は、第２のプリント基板に設けた切欠き内に圧電振動子を嵌合配置して薄型化を図った高安定圧電発振器を提案することを目的としているが、次の如き３つの条件を全て同時に満たさない限りその実現は不可能であるとされ、これまでこのような高安定圧電発振器は実現されていなかった。
即ち、図９に示した如く恒温槽としての金属ブロックを利用しない高安定圧電発振器１００は、圧電振動子１１１内の圧電振動素子を所定の温度に加熱して保温することにより周波数の安定化を図っているため、次の３つの要件を満たす必要がある。
ａ．圧電振動子の缶ケース１０５ａとセラミックヒータ１０６とを密着配置して加熱に際しての熱伝導のロスを少なくすること。
ｂ．金属ケース１０７への放熱を極力抑えて圧電振動子１０５を有効に保温するために、缶ケース１０５ａの外周面と金属ケース１０７との間に１ｍｍ以上の空気層を介在させること。
ｃ．圧電振動子１０５を第２のプリント基板の保温力を利用して保温するために、第２のプリント基板１０３の肉厚を薄くすることなく、第２のプリント基板１０３を圧電振動子の缶ケース１０５ａと接触させること。
しかし、この３つの要件を全て満たしつつ、第２プリント基板１０３に設けた切欠き内に圧電振動子１０５を嵌合配置して高さ７．５ｍｍ以下の薄型化を図った高安定圧電発振器を得ることは困難であるとされていた。具体的には、まず第２プリント基板１０３の一部を切欠いて形成した切欠き内に圧電振動子１０５を配置しようとすると、第２プリント基板上に搭載されるセラミックヒータ１０６と圧電振動子１０５とを離間させざるを得なかったため、要件ａの実現は困難であった。また、切欠き内に圧電振動子を配置すると、第２のプリント基板と圧電振動子とが離間せざるを得ず、その保温力を利用することは不可能であり、要件ｃの実現も困難であった。
更に、従来の高安定圧電発振器は、第２のプリント基板の面上に配置される構造であるため、保温性の点で問題があり、消費電力の増大を避けることができなかった。
【０００５】
【発明が解決しようとする課題】
本発明は上記に鑑みてなされたものであり、表面実装型の第１のプリント基板上にリードピンを介して架設した第２のプリント基板にヒータと圧電振動子等を搭載した上で、これらの部品を含む第１のプリント基板上の空間を圧電振動子等と非接触な状態で金属ケースにより包囲した高安定圧電発振器において、第２のプリント基板に切欠きを形成し、この切欠き内に圧電振動子を嵌合配置しながらも、圧電振動子とヒータとを密着させることによる加温効率の向上と、圧電振動子を第２のプリント基板に近接配置して第２のプリント基板により効率よく保温する構造と、更には厚さ７．５ｍｍ以下という極限に近い薄型化を同時に実現した薄型高安定圧電発振器を提供することを目的とする。
更に、本発明は、温度制御回路によってヒータ温度を制御する構造を備えた圧電発振器において、大型化の原因となる金属ブロック等の恒温槽を用いることなく、極限に近い薄型化を達成すると共に、発振周波数の安定化、低消費電力化、組立性の向上、及び低コスト化という各種要請を同時に満足することができる薄型高安定圧電発振器を提供することを他の目的とする。
【０００６】
【課題を解決するための手段】
上記目的を達成するため、請求項１の発明は、表面実装用の第１のプリント基板と、該第１のプリント基板上に立設した複数のリードピンと、該複数のリードピンの上部に架設固定された第２のプリント基板と、該第２のプリント基板に搭載される圧電振動子と、該圧電振動子を加熱するために第２のプリント基板に搭載されるヒータと、該第２のプリント基板上に搭載される発振回路部品及び温度補償回路部品と、第１のプリント基板上に固定されて前記各構成要素を包囲する金属ケースと、を備えた薄型高安定圧電発振器において、前記第２のプリント基板は、前記圧電振動子を嵌合する切欠きを有した絶縁基板と、該絶縁基板の面上に形成された配線パターンと、を備え、前記切欠きは凹状切欠きであり、該凹状切欠きの対向する２つの端縁に夫々個別に固定されて各端縁近傍に設けた前記配線パターンと電気的に接続されると共に前記圧電振動子及び前記ヒータを密着させた状態で前記凹状切欠き内に嵌合支持する導電接続部材と、を備え、前記ヒータの電極と前記配線パターンとの導通は導電接続部材を介して確保されることを特徴とする。
金属ブロックにより圧電振動子を保温しつつヒータにより加熱する恒温槽型圧電発振器はその小型化、特に低背化に限界があるため、金属ブロックを用いずに第２のプリント基板上において圧電振動子をヒータと密着させて加熱する構造の高安定圧電発振器が提案されている。しかし、この種の高安定圧電発振器は第２のプリント基板と圧電振動子とヒータ等の各部品の厚さが加算された高さとなるため、その薄型化、特に７．５ｍｍを下回る薄型化に限界があった。また、保温性にも問題があり、ヒータによる加熱効率が悪く、消費電力が多くなるという問題があった。
本発明によれば、金属ケース内に収容される第２のプリント基板に設けた切欠き内に圧電振動子とヒータとを密着させた状態で嵌合させるために、金具としての小型の導電接続部材を用いたので、第２のプリント基板の肉厚分だけ薄型化を図ることができ、７．５ｍｍ以下の薄型化を実現し、しかも保温性を高めた薄型高安定圧電発振器を提供することができる。また、組み付け手数も簡略化でき、生産性を高めることができる。
【０００７】
請求項２の発明は、請求項１において、前記導電接続部材は、前記第２のプリント基板に設けた前記凹状切欠きの一つの端縁に係合すると共に該端縁近傍の配線パターンに電気的に接続される係合片と、該係合片に連設されて前記ヒータの電極と接続されるヒータ接続片と、該ヒータ接続片との間でヒータ及び前記圧電振動子を挟圧保持する保持片と、を備えていることを特徴とする。
導電接続部材として板金を単純に加工した極めてシンプルな小型構造を備えたものを採用したので、導電接続部材自体の加工が容易であるばかりでなく、圧電振動子とヒータを導電接続部材に組み付けたユニットを形成する作業も容易であり、このユニットを第２のプリント基板の切欠き内に組み込み、半田固定や結線を行う作業も容易である。従って、生産性を高めることができる。
請求項３の発明は、請求項１又は２において、前記圧電振動子は、圧電振動素子を気密収容した缶ケースと、該缶ケースから外部に突出し前記第２のプリント基板上の配線パターンと接続されるリード端子とを備え、前記導電接続部材と金属ケースとの接触部に、絶縁材料を介在させたことを特徴とする。
これによれば、圧電振動子の缶ケースとヒータの電極とが導電接続部材を介して短絡することを防止できる。
請求項４の発明は、請求項１に記載の薄型高安定圧電発振器において使用される導電接続部材であって、前記第２のプリント基板に設けた凹状切欠きの一つの端縁に係合すると共に該端縁近傍の配線パターンに電気的に接続される係合片と、該係合片に連設されてヒータの電極と接続されるヒータ接続片と、該ヒータ接続片との間でヒータ及び前記圧電振動子を挟圧保持する保持片と、を備えていることを特徴とする。
このようなシンプル構造の導電接続部材を用いれば、圧電振動子とヒータとを密着させた状態でプリント基板に設けた切欠き内に嵌合配置することができるので、当該プリント基板の肉厚分だけ圧電発振器の高さを低背化することができるばかりでなく、プリント基板の保温性を利用して圧電発振器保温性を高め、消費電力を低減できる。
【０００８】
【発明の実施の形態】
以下、本発明を図面に示した実施の形態により詳細に説明する。
図１（ａ）（ｂ）及び（ｃ）は本発明の一実施形態に係る薄型高安定圧電発振器の外観斜視図、Ｘ−Ｘ断面図、及びＹ−Ｙ断面図であり、図２は第２のプリント基板及び導電接続部材等の平面図であり、図３（ａ）及び（ｂ）は導電接続部材の一例の構成を示す斜視図、及び正面図である。
図１に示した薄型高安定圧電発振器１は、表面実装用の外部電極２ａを底部に備えた第１のプリント基板２と、該第１のプリント基板２上の配線パターン（外部電極２ａと導通）上に立設した複数のリードピン３と、複数のリードピン３の上部に架設固定された第２のプリント基板４と、第２のプリント基板４上の配線パターン上に搭載（電気的機械的に接続）される圧電振動子５と、該圧電振動子５を加熱するために第２のプリント基板４に搭載されるチップ部品としてのセラミックヒータ６と、第２のプリント基板４上に搭載される発振回路部品、温度補償回路部品（温度制御回路部品）等の回路部品７と、第１のプリント基板２上のアースパターンに裾部を固定されることにより上記各構成要素を包囲する金属ケース８と、を備えている。
第２のプリント基板４は、圧電振動子５を嵌合する切欠き１１を有したガラスエポキシ、セラミック等から成る絶縁基板１０と、絶縁基板１０の面上に形成された配線パターン１２と、を備えている。この切欠き１１は、図２に示すように絶縁基板１０の一端縁に形成した凹状の切欠きであり、凹状切欠き１１の対向する２つの端縁１１ａの近傍に夫々設けた配線パターン１２ａには夫々導電性接続部材１５が半田により接続固定されている。各導電性接続部材１５は、圧電振動子５及びセラミックヒータ６を凹状切欠き１１内に嵌合支持する役割を果たしている。
導電接続部材１５は、図３に示すように、第２のプリント基板４の凹状切欠き１１の一つの端縁１１ａに係合すると共に端縁近傍の配線パターン１２に電気的に接続される係合片２０、２１と、係合片２０、２１に連設されてセラミックヒータ６の電極と接続されるヒータ接続片２２と、ヒータ接続片２２との間でセラミックヒータ６及び圧電振動子５を挟圧保持する保持片２３と、を備えている。導電接続部材１５に使用する材質は、導電性と熱伝導性に優れた金属、例えば銅、銅合金、アルミ、鉄等を用いる。
【０００９】
図３に示した導電接続部材１５においては、係合片２０、ヒータ接続片２２を一枚の矩形の板金Ａにて構成すると共に、他の係合片２１、保持片２３を他の板金Ｂに屈曲加工と切り起こし加工を施して構成し、これらをスポット溶接等により固定一体化している。即ち、保持片２３は矩形の板金Ｂの一端縁を９０度屈曲させて形成し、係合片２１は当該板金Ｂの他端縁に２本の平行な切り込み線を形成してから両切り込み線間に位置する板金部分を保持片２３とは逆方向へ９０度屈曲させて形成している。係合片２１の両側に位置する細幅の板金部分の先端部を９０度屈曲させて接続片２４とし、この接続片２４を板金Ａ上にスポット溶接により固定している。
なお、係合片２０を半田にて配線パターン１２ａに固定することにより十分な固定強度を確保できるのであれば、他方の係合片２１を省略しても差し支えない。
【００１０】
図４（ａ）（ｂ）は、２つの導電接続部材１５に対してセラミックヒータ６と圧電振動子２１を組み付ける手順を示している。まず（ａ）では、２つの導電接続部材１５をヒータ接続片２２と保持片２３とが対向するように位置決めし、（ｂ）に示すように２つのセラミックヒータ６の各電極６ａを各ヒータ保持片２２上に搭載した状態で半田３０により固定すると共に、セラミックヒータ６と保持片２３との間に圧電振動子５を圧入固定する。
圧電振動子５は、図４（ｃ）に示すように缶ケース５ａと、缶ケース５ａから引き出されたリード端子５ｂとを有している。缶ケース５ａ内には、図示しない圧電振動素子が気密封止された状態でリード端子５ｂの端部に接続支持されている。また、缶ケース５ａの外周には絶縁テープ３１等の絶縁材料を巻き付けて導電接続部材やヒータ電極との間を絶縁している。
【００１１】
次に、図５（ａ）及び（ｂ）はこのように組付けを完了した圧電振動子及びヒータユニット４０を第２のプリント基板４の凹状切欠き１１内に組み付ける手順を示している。
まず、図５（ａ）に示すように２つの係合片２０、２１の間に切欠き１１の端縁１１ａが入り込むように、ユニット４０を差し込む。図５（ｂ）、図１（ｃ）はユニット４０を切欠き１１内に組み付けた状態を示している。続いて、圧電振動子５の２本のリード端子５ｂを第２のプリント基板上のランド１２ｂ上に半田により固定する。
また、図１（ｃ）に示した如く、ヒータ接続片２２とセラミックヒータ６の電極６ａとの間、及び係合片２０と配線パターン１２ａとの間を夫々半田３０により固定する。これによって、ユニット４０の組付けが完了する。
このような構成を備えた圧電発振器１においては、各構成要素は次の如き厚さとすることができる。即ち、第１及び第２のプリント基板２、４の厚さを夫々１ｍｍ、圧電振動子（水晶振動子）５の厚さを３．２ｍｍ、セラミックヒータ６の厚さを０．５ｍｍ、圧電振動子及び第２のプリント基板と金属ケース８の内壁との間の間隔を夫々約１ｍｍ以上、金属ケース８の肉厚を０．２ｍｍとすれば、圧電発振器１の全高さは６．９ｍｍに対して、導電接続部材１５が圧電発振器やヒータの外周面よりも厚さ方向へ突出する量、及び第２のプリント基板上の半田の厚さ方向への突出量を加えた値となり、この合計値は圧電発振器の理想的な高さである７．５ｍｍをクリアすることになる。
【００１２】
次に、図６は本発明の圧電発振器の変形例であり、温度モニタ用のサーミスタ５０の配置例を示している。即ち、凹状切欠き１１の端縁１１ａに沿った一つの配線パターン１２ｃ上にサーミスタ５０を配置して圧電振動子５の温度をモニタし、温度情報を温度制御回路部品にフィードバックすることによってヒータ６による適切な温度制御を行うことが可能となる。
この例では、導電接続部材１５の一部、即ち係合片２１を基板端縁１１ａの基板面から離間させるように構成して、そこに形成される間隙内にサーミスタ５０を配置して係合片２１と接触させるようにしている。なお、この間隙の寸法をサーミスタの高さよりも大きく設定し、サーミスタ５０と係合片２１との間の隙間に樹脂を充填することにより、サーミスタと導電接続部材１５（圧電振動子５）との間の熱伝導率を高めてサーミスタの感度向上を図るようにしてもよい。
次に、図６（ａ）乃至（ｅ）は本発明の他の実施形態に係る導電接続部材を用いた薄型高安定圧電発振器の構成を示す縦断面図、第２のプリント基板の平面図、第２のプリント基板に導電接続部材等を組み付けた状態を示す平面図、側面図、及び導電接続部材の斜視図である。
この実施形態に係る導電接続部材１５は、一枚の矩形の金属板を用いて構成されている点が特徴的である。即ち、この導電接続部材１５は、矩形の板金の上下両端部を同方向に屈曲させて保持片６０及びヒータ接続片６１となし、更に板金本体部分の他面側に切り起こしによって少なくとも一つの係合片６２、６３を形成した構成を備えている。この導電接続部材１５を用いた圧電振動子５、ヒータ６の保持構造、及びこのユニットを第２のプリント基板の切欠き１１内に取り付ける構造は上記の実施形態と同様であるため説明は省略する。
この実施形態に係る導電接続部材１５によれば、スポット溶接等の煩雑な工程を経ることなく製造できるのでコストを低減できる。
【００１３】
また、図８（ａ）及び（ｂ）は本発明の他の実施形態に係る導電接続部材の斜視図、及び加工手順の説明図である。この導電接続部材１５においては、図６の導電接続部材１５が備える２つの係合片６２、６３の内の一方、この例では係合片６３をヒータ接続片６１と同一平面上に配置した構成が異なっている。
図８（ｂ）に示すように板金面の中央部にＨ型のスリットを形成してから、各折れ線に沿って折り曲げることにより、（ａ）に示した如き構成を実現できるので、図６の例と同様にスポット溶接等の煩雑な工程を省略した低コストな導電接続部材を得ることができる。
【００１４】
【発明の効果】
以上のように本発明によれば、第２のプリント基板に形成した切欠き内に圧電振動子を嵌合配置しながらも、圧電振動子とヒータとを密着させることによる加温効率の向上と、圧電振動子を第２のプリント基板に近接配置して第２のプリント基板により効率よく保温する構造と、更には厚さ７．５ｍｍ以下という極限に近い薄型化を同時に実現した薄型高安定圧電発振器を提供することができる。
また、温度制御回路によってヒータ温度を制御する構造を備えた圧電発振器において、大型化の原因となる金属ブロック等の恒温槽を用いることなく、極限に近い薄型化を達成すると共に、発振周波数の安定化、低消費電力化、組立性の向上、及び低コスト化という各種要請を同時に満足することができる薄型高安定圧電発振器を提供することができる。
即ち、まず請求項１の発明によれば、金属ケース内に金属ケースとは非接触で収容される第２のプリント基板に設けた切欠き内に圧電振動子とヒータとを密着させた状態で嵌合させるために、小型の導電接続部材を用いたので、第２のプリント基板の肉厚分だけ薄型化を図ることができ、７．５ｍｍ以下の薄型化を実現し、しかも保温性を高めた薄型高安定圧電発振器を提供することができる。また、組み付け手数も簡略化でき、生産性を高めることができる。
【００１５】
請求項２の発明によれば、導電接続部材として板金を単純に加工した極めてシンプルな小型構造を備えたものを採用したので、導電接続部材自体の加工が容易であるばかりでなく、圧電振動子とヒータを導電接続部材に組み付けたユニットを形成する作業も容易であり、このユニットを第２のプリント基板の切欠き内に組み込み、半田固定や結線を行う作業も容易である。従って、生産性を高めることができる。
請求項３の発明によれば、圧電振動子の缶ケースとヒータの電極とが導電接続部材を介して短絡することを防止できる。
請求項４の発明によれば、圧電振動子とヒータとを密着させた状態でプリント基板に設けた切欠き内に嵌合配置することができるので、当該プリント基板の肉厚分だけ圧電発振器の高さを低背化することができるばかりでなく、プリント基板の保温性を利用して圧電発振器保温性を高め、消費電力を低減できる。
【図面の簡単な説明】
【図１】（ａ）（ｂ）及び（ｃ）は本発明の一実施形態に係る薄型高安定圧電発振器の外観斜視図、Ｘ−Ｘ断面図、及びＹ−Ｙ断面図。
【図２】第２のプリント基板及び導電接続部材等の平面図。
【図３】（ａ）及び（ｂ）は導電接続部材の一例の構成を示す斜視図、及び正面図。
【図４】（ａ）乃至（ｃ）は２つの導電接続部材に対してセラミックヒータと圧電振動子を組み付ける手順を示す図。
【図５】（ａ）及び（ｂ）は組付けを完了した圧電振動子及びヒータユニットを第２のプリント基板の凹状切欠き内に組み付ける手順を示す図。
【図６】本発明の圧電発振器の変形例の要部構成図。
【図７】（ａ）乃至（ｅ）は本発明の他の実施形態に係る導電接続部材を用いた薄型高安定圧電発振器の構成を示す縦断面図、第２のプリント基板の平面図、第２のプリント基板に導電接続部材等を組み付けた状態を示す平面図、側面図、及び導電接続部材の斜視図。
【図８】（ａ）及び（ｂ）は本発明の他の実施形態に係る導電接続部材の斜視図、及び加工手順の説明図。
【図９】従来例に係る圧電発振器の構成を示す縦断面図。
【図１０】他の従来例の説明図。
【符号の説明】
１　薄型高安定圧電発振器、２　第１のプリント基板、２ａ　表面実装用の外部電極、３　リードピン、４　第２のプリント基板、５　圧電振動子、５ａ　缶ケース、５ｂ　リード端子、６　セラミックヒータ、７　回路部品、８　金属ケース、１０　絶縁基板、１１　切欠き、１１ａ　端縁、１２、１２ａ、１２ｂ、１２ｃ　配線パターン、１５　導電性接続部材、２０、２１　係合片、２２　ヒータ接続片、２３　保持片、２４　接合片、３０　半田、３１　絶縁テープ（絶縁材）、４０　ユニット、５０　サーミスタ、６１　ヒータ接続片、６２、６３
係合片。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a piezoelectric oscillator used as a frequency control device or the like, in particular, a piezoelectric oscillator that heats a piezoelectric vibrator with a heater and has a configuration in which a heater temperature is controlled by a temperature control circuit, but which can be made thinner. And a conductive connecting member.
[0002]
[Prior art]
As a piezoelectric oscillator such as a crystal oscillator which is a frequency control device used for mobile communication equipment and transmission communication equipment, a thermostatic oven type piezoelectric oscillator which can output a highly stable frequency without being affected by an external temperature change is known. Have been.
Furthermore, in recent years, in these fields, various devices have been required to be small, light, and portable, and accordingly, there has been a corresponding demand from the market for thermostatic chamber type piezoelectric oscillators. Have been.
That is, the height dimension of the conventional thermostatic oven type piezoelectric oscillator is usually 20 mm or more, and depending on the case, a type whose size is increased to about 50 mm has been frequently used. However, in recent years, in response to miniaturization of various devices, it has been strongly demanded that a thermostatic chamber type piezoelectric oscillator be reduced in height to the same height as other large components.
By the way, in order to obtain a highly stable frequency, a conventional thermostatic oven type piezoelectric oscillator accommodates a piezoelectric vibrator in a recess of a thermostatic oven (open) such as a metal block having a large heat capacity, and further heats the metal block by a heater. Had been heated to the temperature. However, if a large-sized metal block is used as a thermostat, the bulk of the oscillator as a whole increases, so that it has not been possible to satisfy the demand for a reduction in size and weight. Further, since the piezoelectric vibrating element inside the piezoelectric vibrator is heated via the metal block, there is a problem that it takes a long time until heat from the heater reaches the piezoelectric vibrating element and reaches a predetermined frequency.
In such a conventional thermostatic oven type piezoelectric oscillator, since a metal block is used, the height dimension of the entire oscillator is 9.2 mm, no matter how much effort is taken to reduce the thickness. Is the limit, and it has been difficult to keep it below that limit.
[0003]
From such a point, as shown in the cross-sectional view of FIG. 9, a surface-mounted thin high-stability piezoelectric oscillator having a configuration in which a piezoelectric vibrator is heated using a heater without using a metal block has been proposed. . The thin high-stability piezoelectric oscillator (hereinafter, referred to as a piezoelectric oscillator) 100 includes a first printed circuit board 101 having an external electrode 101a for surface mounting on the bottom, and a wiring pattern (external electrode) on the first printed circuit board 101. Lead wires 102 erected from the first printed circuit board 103, a second printed circuit board 103 having a wiring pattern connected and fixed to the top of the lead pins 102 and electrically connected to the lead pins 102, and a wiring pattern on the bottom surface of the second printed circuit board 103. The electrode portion is formed on the piezoelectric vibrator 105 positioned on the lower surface side of the second printed board by connecting the lead terminal 105b and the wiring pattern on the lower surface of the second printed board facing the can case 105a of the piezoelectric vibrator 105. The ceramic heater 106 connected and arranged is connected to a circuit component (oscillation circuit unit) mounted on the second printed circuit board 103. , And a temperature control circuit components and the like) 107, the metal case 108 fixed to the first printed circuit board to enclose a space containing the components on the first printed circuit board 101, a.
In this piezoelectric oscillator 100, a second printed circuit board 103 supporting a piezoelectric vibrator 105 is arranged so as to be floated at substantially the center of the space inside the metal case, and the first printed circuit board 101 and the can case 105a are connected to each other. The thermal coupling is configured to be coarse. Further, the piezoelectric vibrator 105 is arranged as close as possible to the lower surface (or upper surface) of the second printed circuit board 103 so as to make the piezoelectric vibrator 105 as thin as possible. Since the thickness of the substrate 103 itself and the thicknesses of the piezoelectric vibrator 105, the heater 106, and the circuit component 107 are all taken into account, there is a limit to the reduction in thickness.
That is, for example, the thicknesses of the first and second printed circuit boards 101 and 103 are each 1 mm, the thickness of the piezoelectric vibrator 105 is 3.2 mm, the thickness of the ceramic heater 106 is 0.5 mm, and the piezoelectric vibrator and the first If the distance between the printed circuit board 2 and the inner wall of the metal case 108 is about 1 mm or more and the thickness of the metal case 108 is 0.2 mm, the height of the piezoelectric oscillator 100 is limited to 7.7 mm. Therefore, it cannot meet the demand for further height reduction of 7.5 mm or less.
[0004]
Next, FIG. 10 is a view for explaining measures to reduce the thickness of a normal type piezoelectric oscillator without a heater. A piezoelectric vibrator 111 is mounted on a printed circuit board 110 (second printed circuit board) on which a circuit component 112 is mounted. At the time of mounting, a part of the printed circuit board 110 is cut out, a metal case 111a of the piezoelectric vibrator 111 is dropped and arranged in the cutout, and the lead terminal 111b is connected by soldering to a wiring pattern on the printed circuit board 110. ing. With this configuration, the height dimension of the piezoelectric oscillator can be reduced by the thickness of the printed circuit board. However, such a structure for reducing the thickness is highly stable as shown in FIG. It has been said that application to the piezoelectric oscillator 100 is difficult.
As described below, an object of the present invention is to propose a highly stable piezoelectric oscillator in which a piezoelectric vibrator is fitted and arranged in a notch provided in a second printed circuit board to reduce the thickness. Unless all three conditions are satisfied at the same time, it is considered impossible to realize this, and such a highly stable piezoelectric oscillator has not been realized until now.
That is, as shown in FIG. 9, the high-stable piezoelectric oscillator 100 that does not use a metal block as a thermostatic chamber stabilizes the frequency by heating the piezoelectric vibrating element in the piezoelectric vibrator 111 to a predetermined temperature and keeping it warm. Therefore, it is necessary to satisfy the following three requirements.
a. The can case 105a of the piezoelectric vibrator and the ceramic heater 106 are arranged in close contact with each other to reduce heat conduction loss during heating.
b. In order to minimize heat radiation to the metal case 107 and effectively keep the temperature of the piezoelectric vibrator 105, an air layer of 1 mm or more is provided between the outer peripheral surface of the can case 105a and the metal case 107.
c. In order to keep the piezoelectric vibrator 105 warm by using the heat retaining force of the second printed circuit board, the second printed circuit board 103 can be replaced with a piezoelectric vibrator can case without reducing the thickness of the second printed circuit board 103. 105a.
However, a high-stable piezoelectric oscillator having a height of 7.5 mm or less by fitting and arranging the piezoelectric vibrator 105 in a notch provided in the second printed circuit board 103 while satisfying all three requirements is provided. It was considered difficult to obtain. Specifically, first, when the piezoelectric vibrator 105 is to be arranged in a cutout formed by cutting out a part of the second printed board 103, the ceramic heater 106 and the piezoelectric vibrator 105 mounted on the second printed board 103 Has to be separated, and it is difficult to realize the requirement a. Further, when the piezoelectric vibrator is arranged in the notch, the second printed circuit board and the piezoelectric vibrator must be separated from each other, and it is impossible to use the heat retaining power, and it is difficult to realize the requirement c. Met.
Furthermore, the conventional high-stable piezoelectric oscillator has a structure in which it is disposed on the surface of the second printed circuit board, and thus has a problem in heat insulation, and it is not possible to avoid an increase in power consumption.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above, and a heater, a piezoelectric vibrator, and the like are mounted on a second printed circuit board which is provided via lead pins on a surface mounted first printed circuit board. A notch is formed in a second printed circuit board in a highly stable piezoelectric oscillator in which a space on a first printed circuit board including components is surrounded by a metal case in a non-contact state with a piezoelectric vibrator or the like. While the piezoelectric vibrator is fitted and arranged, the heating efficiency is improved by bringing the piezoelectric vibrator and the heater into close contact, and the piezoelectric vibrator is disposed close to the second printed circuit board to improve the efficiency by the second printed circuit board. It is an object of the present invention to provide a thin and highly stable piezoelectric oscillator that simultaneously realizes a structure that keeps heat well and a thickness that is as thin as 7.5 mm or less, which is close to the limit.
Furthermore, the present invention achieves a thinnest near the limit without using a constant temperature bath such as a metal block that causes a size increase in a piezoelectric oscillator having a structure in which a heater temperature is controlled by a temperature control circuit. It is another object of the present invention to provide a thin and highly stable piezoelectric oscillator that can simultaneously satisfy various requirements of stabilizing the oscillation frequency, reducing power consumption, improving assemblability, and reducing cost.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is a first printed circuit board for surface mounting, a plurality of lead pins erected on the first printed circuit board, and a bridge fixed above the plurality of lead pins. A second printed circuit board, a piezoelectric vibrator mounted on the second printed circuit board, a heater mounted on the second printed circuit board for heating the piezoelectric vibrator, and the second printed circuit board. A thin, high-stable piezoelectric oscillator, comprising: an oscillation circuit component and a temperature compensation circuit component mounted on a substrate; and a metal case fixed on a first printed circuit board and surrounding the components. The printed board includes an insulating substrate having a notch for fitting the piezoelectric vibrator, and a wiring pattern formed on a surface of the insulating substrate, wherein the notch is a concave notch, Two opposing concave notches Each of the piezoelectric vibrators and the heaters are individually fixed to an edge and electrically connected to the wiring pattern provided in the vicinity of the edge, and are fitted and supported in the concave notch in a state where the piezoelectric vibrator and the heater are in close contact with each other. A conductive connection member, wherein conduction between the electrode of the heater and the wiring pattern is ensured via the conductive connection member.
The thermostatic oven type piezoelectric oscillator, in which the piezoelectric vibrator is heated by the heater while the piezoelectric vibrator is kept warm by the metal block, has a limit in miniaturization, especially in height reduction. Therefore, the piezoelectric vibrator can be formed on the second printed circuit board without using the metal block. There has been proposed a highly stable piezoelectric oscillator having a structure in which a heater is brought into close contact with a heater and heated. However, this kind of high-stability piezoelectric oscillator has a height that is the sum of the thicknesses of the components such as the second printed circuit board, the piezoelectric vibrator, and the heater, so that the thickness is reduced, particularly, to less than 7.5 mm. There was a limit. In addition, there is a problem in heat retention, and there is a problem that heating efficiency by a heater is poor and power consumption is increased.
According to the present invention, the piezoelectric vibrator and the heater are fitted in a notch provided in the second printed circuit board accommodated in the metal case in a state where the piezoelectric vibrator and the heater are in close contact with each other. Since a member is used, the thickness can be reduced by the thickness of the second printed circuit board, and a thin, highly stable piezoelectric oscillator that achieves a thickness of 7.5 mm or less and has improved heat retention is provided. Can be. Further, the number of assembling steps can be simplified, and the productivity can be increased.
[0007]
According to a second aspect of the present invention, in the first aspect, the conductive connection member is engaged with one edge of the concave notch provided in the second printed circuit board and electrically connected to a wiring pattern near the edge. And a heater connecting piece connected to the electrode of the heater, the heater and the piezoelectric vibrator being held between the connecting piece and the heater connecting piece. And a holding piece to be formed.
As a conductive connection member, one with a very simple small structure made by simply processing sheet metal was adopted, so not only was the processing of the conductive connection member itself easy, but also the piezoelectric vibrator and heater were assembled to the conductive connection member. The work of forming the unit is easy, and the work of mounting this unit in the cutout of the second printed circuit board and fixing and connecting the solder is also easy. Therefore, productivity can be improved.
According to a third aspect of the present invention, in the first or second aspect, the piezoelectric vibrator is connected to a can case accommodating the piezoelectric vibrating element in an airtight manner, and protrudes outside from the can case to a wiring pattern on the second printed circuit board. And a contact portion between the conductive connecting member and the metal case, wherein an insulating material is interposed.
According to this, it is possible to prevent a short circuit between the can case of the piezoelectric vibrator and the electrode of the heater via the conductive connection member.
According to a fourth aspect of the present invention, there is provided a conductive connecting member used in the thin high-stability piezoelectric oscillator according to the first aspect, wherein the conductive connecting member is engaged with one edge of a concave notch provided in the second printed circuit board. An engagement piece electrically connected to the wiring pattern near the edge, a heater connection piece connected to the electrode of the heater connected to the engagement piece, and a heater between the heater connection piece and the heater connection piece. And a holding piece for holding the piezoelectric vibrator under pressure.
By using the conductive connection member having such a simple structure, the piezoelectric vibrator and the heater can be fitted and arranged in the notch provided in the printed board in a state where the piezoelectric vibrator and the heater are in close contact with each other. Not only can the height of the piezoelectric oscillator be reduced, but also the heat insulation of the printed circuit board can be used to enhance the heat retention of the piezoelectric oscillator and reduce power consumption.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
1 (a), 1 (b) and 1 (c) are an external perspective view, an XX sectional view, and a YY sectional view of a thin high-stability piezoelectric oscillator according to an embodiment of the present invention, and FIG. 3A and 3B are a perspective view and a front view, respectively, showing the configuration of an example of a conductive connecting member.
The thin high-stability piezoelectric oscillator 1 shown in FIG. 1 includes a first printed circuit board 2 having an external electrode 2a for surface mounting at the bottom, and a wiring pattern (conductively connected to the external electrode 2a) on the first printed circuit board 2. A) a plurality of lead pins 3 erected above, a second printed circuit board 4 erected and fixed above the plurality of lead pins 3, and mounted on a wiring pattern on the second printed circuit board 4 (electrically and mechanically). Connected), a ceramic heater 6 as a chip component mounted on the second printed circuit board 4 for heating the piezoelectric vibrator 5, and mounted on the second printed circuit board 4. A circuit component 7 such as an oscillation circuit component and a temperature compensation circuit component (temperature control circuit component); and a metal case 8 surrounding the above components by fixing the skirt to a ground pattern on the first printed circuit board 2. And .
The second printed circuit board 4 includes an insulating substrate 10 made of glass epoxy, ceramic or the like having a notch 11 into which the piezoelectric vibrator 5 is fitted, and a wiring pattern 12 formed on the surface of the insulating substrate 10. Have. The notch 11 is a concave notch formed at one edge of the insulating substrate 10 as shown in FIG. 2, and is formed in a wiring pattern 12 a provided near two opposing edges 11 a of the concave notch 11. The conductive connection members 15 are respectively connected and fixed by soldering. Each conductive connection member 15 has a function of fitting and supporting the piezoelectric vibrator 5 and the ceramic heater 6 in the concave notch 11.
As shown in FIG. 3, the conductive connection member 15 is engaged with one edge 11a of the concave notch 11 of the second printed circuit board 4 and is electrically connected to the wiring pattern 12 near the edge. The ceramic heater 6 and the piezoelectric vibrator 5 are connected between the mating pieces 20 and 21, the heater connecting piece 22 connected to the electrodes of the ceramic heater 6 and connected to the engaging pieces 20 and 21, and the heater connecting piece 22. And a holding piece 23 for holding the holding pressure. The material used for the conductive connection member 15 is a metal having excellent conductivity and heat conductivity, for example, copper, copper alloy, aluminum, iron, or the like.
[0009]
In the conductive connecting member 15 shown in FIG. 3, the engaging piece 20 and the heater connecting piece 22 are formed of one rectangular sheet metal A, and the other engaging piece 21 and the holding piece 23 are formed of another sheet metal B. Are bent and cut and raised, and these are fixedly integrated by spot welding or the like. That is, the holding piece 23 is formed by bending one end edge of the rectangular sheet metal B by 90 degrees, and the engaging piece 21 forms two parallel cut lines at the other end edge of the sheet metal B, and then forms both cut lines. The sheet metal portion located therebetween is formed by bending the holding piece 23 by 90 degrees in the opposite direction. The distal ends of the narrow sheet metal portions located on both sides of the engagement piece 21 are bent by 90 degrees to form connection pieces 24, and the connection pieces 24 are fixed on the sheet metal A by spot welding.
In addition, if sufficient fixing strength can be secured by fixing the engaging piece 20 to the wiring pattern 12a with solder, the other engaging piece 21 may be omitted.
[0010]
FIGS. 4A and 4B show a procedure for assembling the ceramic heater 6 and the piezoelectric vibrator 21 to the two conductive connection members 15. First, in (a), the two conductive connection members 15 are positioned so that the heater connection piece 22 and the holding piece 23 face each other, and as shown in (b), each electrode 6a of the two ceramic heaters 6 is held by each heater. The piezoelectric vibrator 5 is press-fitted and fixed between the ceramic heater 6 and the holding piece 23 while being fixed on the piece 22 with the solder 30.
As shown in FIG. 4C, the piezoelectric vibrator 5 has a can case 5a and lead terminals 5b drawn from the can case 5a. In the can case 5a, a piezoelectric vibration element (not shown) is connected to and supported by the end of the lead terminal 5b in a hermetically sealed state. An insulating material such as an insulating tape 31 is wrapped around the outer periphery of the can case 5a to insulate between the conductive connecting member and the heater electrode.
[0011]
Next, FIGS. 5A and 5B show a procedure for assembling the piezoelectric vibrator and the heater unit 40 which have been thus assembled into the concave notch 11 of the second printed circuit board 4.
First, as shown in FIG. 5A, the unit 40 is inserted so that the edge 11a of the notch 11 enters between the two engagement pieces 20 and 21. FIGS. 5B and 1C show a state in which the unit 40 is assembled in the notch 11. Subsequently, the two lead terminals 5b of the piezoelectric vibrator 5 are fixed on the lands 12b on the second printed circuit board by soldering.
Further, as shown in FIG. 1C, the solder 30 is fixed between the heater connecting piece 22 and the electrode 6a of the ceramic heater 6, and between the engaging piece 20 and the wiring pattern 12a. Thus, the assembly of the unit 40 is completed.
In the piezoelectric oscillator 1 having such a configuration, each component can have the following thickness. That is, the thickness of each of the first and second printed circuit boards 2 and 4 is 1 mm, the thickness of the piezoelectric vibrator (crystal vibrator) 5 is 3.2 mm, the thickness of the ceramic heater 6 is 0.5 mm, and the piezoelectric vibration Assuming that the distance between each of the first and second printed circuit boards and the inner wall of the metal case 8 is about 1 mm or more, and the thickness of the metal case 8 is 0.2 mm, the total height of the piezoelectric oscillator 1 is 6.9 mm. Thus, the sum of the amount by which the conductive connection member 15 protrudes in the thickness direction from the outer peripheral surface of the piezoelectric oscillator or the heater and the amount by which the solder on the second printed circuit board protrudes in the thickness direction is added. Clears the ideal height of the piezoelectric oscillator of 7.5 mm.
[0012]
Next, FIG. 6 shows a modification of the piezoelectric oscillator of the present invention, and shows an arrangement example of a thermistor 50 for temperature monitoring. That is, the thermistor 50 is arranged on one wiring pattern 12c along the edge 11a of the concave notch 11 to monitor the temperature of the piezoelectric vibrator 5, and feeds back the temperature information to the temperature control circuit component, thereby making the heater 6 , It is possible to perform appropriate temperature control.
In this example, a part of the conductive connecting member 15, that is, the engaging piece 21 is configured to be separated from the substrate surface of the substrate edge 11a, and the thermistor 50 is disposed in a gap formed there and engaged. The pieces 21 are brought into contact with each other. The size of the gap is set to be larger than the height of the thermistor, and the gap between the thermistor 50 and the engagement piece 21 is filled with resin, so that the gap between the thermistor and the conductive connection member 15 (piezoelectric vibrator 5) is increased. The thermal conductivity of the thermistor may be increased to improve the sensitivity of the thermistor.
Next, FIGS. 6A to 6E are longitudinal sectional views showing a configuration of a thin high-stable piezoelectric oscillator using a conductive connection member according to another embodiment of the present invention, a plan view of a second printed circuit board, It is a top view, a side view, and a perspective view of a conductive connection member showing the state where a conductive connection member and the like were assembled on a second printed circuit board.
The conductive connection member 15 according to this embodiment is characterized in that it is configured using a single rectangular metal plate. That is, this conductive connecting member 15 is formed by bending upper and lower ends of a rectangular sheet metal in the same direction to form a holding piece 60 and a heater connecting piece 61, and further, by cutting and raising the other side of the sheet metal main body, at least one connection member. It has a configuration in which mating pieces 62 and 63 are formed. The structure for holding the piezoelectric vibrator 5 and the heater 6 using the conductive connection member 15 and the structure for mounting the unit in the cutout 11 of the second printed circuit board are the same as those in the above-described embodiment, and therefore the description thereof is omitted. .
According to the conductive connection member 15 according to this embodiment, it is possible to manufacture without conducting a complicated process such as spot welding, so that the cost can be reduced.
[0013]
8A and 8B are a perspective view of a conductive connecting member according to another embodiment of the present invention and an explanatory view of a processing procedure. In this conductive connecting member 15, one of the two engaging pieces 62 and 63 provided in the conductive connecting member 15 of FIG. 6, in this example, the engaging piece 63 is arranged on the same plane as the heater connecting piece 61. Are different.
Since an H-shaped slit is formed at the center of the sheet metal surface as shown in FIG. 8B and then bent along each broken line, the configuration as shown in FIG. 8A can be realized. As in the example, it is possible to obtain a low-cost conductive connecting member in which complicated steps such as spot welding are omitted.
[0014]
【The invention's effect】
As described above, according to the present invention, while the piezoelectric vibrator is fitted and arranged in the notch formed in the second printed circuit board, the heating efficiency is improved by bringing the piezoelectric vibrator and the heater into close contact with each other. , A structure in which the piezoelectric vibrator is arranged close to the second printed circuit board to keep the temperature efficiently by the second printed circuit board, and furthermore, a thin and highly stable piezoelectric material which realizes a thickness as thin as 7.5 mm or less, which is close to the limit. An oscillator can be provided.
In addition, in a piezoelectric oscillator that has a structure in which the heater temperature is controlled by a temperature control circuit, it is possible to achieve an extremely thin type without using a constant temperature bath such as a metal block that causes the size to increase, and to stabilize the oscillation frequency. It is possible to provide a thin high-stability piezoelectric oscillator that can simultaneously satisfy various demands of low power consumption, low power consumption, improvement in assemblability, and low cost.
That is, according to the first aspect of the present invention, the piezoelectric vibrator and the heater are brought into close contact with each other in a notch provided in the second printed board accommodated in the metal case in a non-contact manner with the metal case. Since a small conductive connecting member is used for fitting, the thickness can be reduced by the thickness of the second printed circuit board, and the thickness can be reduced to 7.5 mm or less, and the heat retaining property can be improved. A thin and highly stable piezoelectric oscillator can be provided. Further, the number of assembling steps can be simplified, and the productivity can be increased.
[0015]
According to the second aspect of the present invention, since the conductive connecting member having a very simple and small structure formed by simply processing a sheet metal is employed, not only is the processing of the conductive connecting member itself easy, but also a piezoelectric vibrator. It is also easy to form a unit in which the unit and the heater are assembled to the conductive connection member, and it is also easy to incorporate this unit into a notch in the second printed circuit board and perform solder fixing and connection. Therefore, productivity can be improved.
According to the third aspect of the invention, it is possible to prevent a short circuit between the can case of the piezoelectric vibrator and the electrode of the heater via the conductive connection member.
According to the invention of claim 4, since the piezoelectric vibrator and the heater can be fitted and arranged in the notch provided in the printed circuit board in a state where the piezoelectric vibrator and the heater are brought into close contact with each other, the piezoelectric oscillator is provided by the thickness of the printed circuit board. Not only can the height be reduced, but also the thermal insulation of the piezoelectric oscillator can be enhanced by using the thermal insulation of the printed circuit board, and the power consumption can be reduced.
[Brief description of the drawings]
FIGS. 1A, 1B and 1C are an external perspective view, a cross-sectional view along XX, and a cross-sectional view along YY of a thin high-stability piezoelectric oscillator according to an embodiment of the present invention.
FIG. 2 is a plan view of a second printed circuit board, a conductive connection member, and the like.
FIGS. 3A and 3B are a perspective view and a front view showing a configuration of an example of a conductive connection member.
FIGS. 4A to 4C are diagrams showing a procedure for assembling a ceramic heater and a piezoelectric vibrator to two conductive connection members.
FIGS. 5A and 5B are diagrams showing a procedure for assembling the assembled piezoelectric vibrator and heater unit into a concave cutout of a second printed circuit board.
FIG. 6 is a main part configuration diagram of a modified example of the piezoelectric oscillator of the present invention.
FIGS. 7A to 7E are longitudinal sectional views showing a configuration of a thin high-stable piezoelectric oscillator using a conductive connecting member according to another embodiment of the present invention, a plan view of a second printed circuit board, and FIGS. The top view, the side view, and the perspective view of a conductive connection member which show the state which attached the conductive connection member etc. to the 2 printed circuit boards.
8A and 8B are a perspective view of a conductive connecting member according to another embodiment of the present invention and an explanatory view of a processing procedure.
FIG. 9 is a longitudinal sectional view showing the configuration of a piezoelectric oscillator according to a conventional example.
FIG. 10 is an explanatory view of another conventional example.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 thin high-stability piezoelectric oscillator, 2 first printed board, 2 a external electrode for surface mounting, 3 lead pin, 4 second printed board, 5 piezoelectric vibrator, 5 a can case, 5 b lead terminal, 6 ceramic heater, 7 Circuit component, 8 metal case, 10 insulating substrate, 11 notch, 11a edge, 12, 12a, 12b, 12c wiring pattern, 15 conductive connecting member, 20, 21 engaging piece, 22 heater connecting piece, 23 holding piece , 24 joining pieces, 30 solder, 31 insulating tape (insulating material), 40 units, 50 thermistor, 61 heater connecting pieces, 62, 63
Engagement piece.

Claims

A first printed board for surface mounting, a plurality of lead pins erected on the first printed board, a second printed board erected and fixed above the plurality of lead pins, and the second printed board A piezoelectric vibrator mounted on a substrate, a heater mounted on a second printed circuit board for heating the piezoelectric vibrator, an oscillation circuit component and a temperature compensation circuit component mounted on the second printed circuit board And a metal case fixed on a first printed circuit board and surrounding each of the constituent elements.
The second printed circuit board includes: an insulating substrate having a notch for fitting the piezoelectric vibrator; and a wiring pattern formed on a surface of the insulating substrate.
The notch is a concave notch, and the notch is individually fixed to two opposing edges of the concave notch, and is electrically connected to the wiring pattern provided near each edge, and the piezoelectric vibrator is provided. And a conductive connection member fitted and supported in the concave notch in a state where the heater is in close contact with the heater,
A thin and highly stable piezoelectric oscillator, wherein conduction between the electrode of the heater and the wiring pattern is ensured via a conductive connecting member.

An engagement piece that engages with one edge of the concave notch provided in the second printed circuit board and is electrically connected to a wiring pattern near the edge; A heater connecting piece connected to the heater and connected to an electrode of the heater, and a holding piece for holding the heater and the piezoelectric vibrator between the heater connecting piece and the heater connecting piece. The thin high-stability piezoelectric oscillator according to claim 1.

The piezoelectric vibrator includes a can case in which a piezoelectric vibrating element is hermetically housed, and a lead terminal projecting outside from the can case and connected to a wiring pattern on the second printed circuit board,
3. The thin and highly stable piezoelectric oscillator according to claim 1, wherein an insulating material is interposed at a contact portion between the conductive connecting member and the metal case.

2. A conductive connecting member used in the thin high-stability piezoelectric oscillator according to claim 1, wherein the wiring is engaged with one edge of a concave notch provided in the second printed circuit board and near the edge. An engagement piece electrically connected to the pattern, a heater connection piece connected to the heater electrode connected to the engagement piece, and the heater and the piezoelectric vibrator sandwiched between the heater connection piece and the heater connection piece; And a holding piece for pressure-holding the conductive connecting member.