JP4262804B2

JP4262804B2 - Hot air heating device

Info

Publication number: JP4262804B2
Application number: JP24452498A
Authority: JP
Inventors: 昌弘谷口; 公仁桑原; 耕一永井
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 1998-08-31
Filing date: 1998-08-31
Publication date: 2009-05-13
Anticipated expiration: 2018-08-31
Also published as: JP2000077843A

Description

【０００１】
【発明の属する技術分野】
本発明は、プリント基板に電子部品をリフロー半田付けするために使用したり、フロー半田付けに際して熱硬化性接着剤を硬化させるために使用する熱風加熱装置に関するものである。
【０００２】
【従来の技術】
従来より、面実装部品をプリント基板に半田付けする方法として、リフロー法とフロー法が用いられている。
【０００３】
リフロー法は、プリント基板にソルダーペーストを印刷等で塗布してその上に電子部品を装着し、その状態のプリント基板を加熱することで、ソルダーペーストを溶かし、半田付けするものである。
【０００４】
また、面実装部品のフロー法は、プリント基板に接着剤を塗布してその上に電子部品を装着し、接着剤を硬化させた後、プリント基板を反転し、噴流式半田槽にプリント基板を浸けることで、半田付けをする方法である。この場合、プリント基板にはリード付き部品も実装してあることが多いので、接着剤硬化時の加熱には、リード付き部品のある側の温度はできるだけ低くする必要がある。そのため、プリント基板の熱風加熱装置では、プリント基板の接着剤塗布面の温度は接着剤の硬化温度、例えば１３０℃以上の温度に加熱でき、プリント基板のリード付き部品の実装面は、リード付き部品の耐熱温度以下、例えば１００℃以下の温度にすることが要求される。
【０００５】
従って、リフロー加熱（リフロー法）と、接着剤硬化加熱（フロー法）とはそれぞれ違う設備を使用していたが、同じ設備でリフロー加熱（リフロー法）と接着剤加熱（フロー法）が可能な装置の要求が出ており、その結果種々の加熱装置が開発された。
【０００６】
その一例を図８に示す。プリント基板１は搬送装置２によって搬送経路を矢印Ａの方向へ搬送されて炉３の３組の加熱ユニット３ａ、３ｂ、３ｃの内部を通過する。炉３の内部では、矢印ａに示すように炉３の内部へ送り込まれた空気が、噴き出しノズル４から矢印ｂのように噴き出され、その空気の一部は矢印ｃを経て排気口５から矢印ｄのように排気され、残りの空気は炉３の内部で循環している。
【０００７】
リフロー半田付け時には、パネルヒータ６ａ、６ｂ、６ｃおよび、７ａ、７ｂ、７ｃで炉３の内部を赤外線で加熱し、噴き出しノズル４からの空気で攪拌されてプリント基板１の均一加熱が実現されている。
【０００８】
また、フロー半田付けの接着剤硬化時には下側のパネルヒータ７ａ、７ｂ、７ｃと噴き出しノズル４からの空気流をＯＦＦ状態にし、排気口５から矢印ｄのように排気しながら、上側のパネルヒータ６ａ、６ｂ、６ｃだけで加熱する。このようにして、炉３内の雰囲気温度をさげ、プリント基板１の下面温度を低く保つ方法などが開発されてきた。
【０００９】
【発明が解決しようとする課題】
ところで、最近、リフロー加熱時においても、プリント基板の半田付け面と反対側の面とで、温度差を付ける要望が出てきているが、プリント基板の半田付け面と前記半田付け面とは反対側の面とで温度差を付けるために、熱風加熱装置として赤外線加熱を採用すると、プリント基板と電子部品の赤外線吸収率の差や、熱容量の差により、同一基板内の温度差や、部品間の温度差が大きくなるという問題があった。
【００１０】
また、上記従来の加熱装置においては、熱風の一部を排気口５から排気するようにしていたので、熱効率が悪く、又炉３内の温度を精度良くコントロールすることができずに、温度のばらつきが生じるという問題があった。
【００１１】
さらに図８に示すものは３組の加熱ユニット３ａ、３ｂ、３ｃを備えているが、各加熱ユニット３ａ、３ｂ、３ｃの相互の熱影響があって、それぞれの加熱ユニット３ａ、３ｂ、３ｃ内の温度コントロールが困難であるという問題があった。
【００１２】
本発明は、上記従来の問題を解消し、搬送装置の搬送面に配設され、電子部品を実装したプリント基板の上下両面から効率良く熱風を供給でき、しかも、熱風をケーシング内で良好に循環できて熱効率が良く、プリント基板に吹き付けられる熱風の温度のばらつきを最小限に抑え、この温度を効率良くコントロールできる熱風加熱装置を提供することを目的としている。
【００１３】
【課題を解決するための手段】
上記目的を達成するために、本願の第 1発明の熱風加熱装置は、基板を搬送する搬送面を中央にして、その上下に複数組の熱風加熱ユニットがそれぞれ配置され、前記上下の熱風加熱ユニットのそれぞれのケーシング内には、空気を循環送風するためのファンと、送風される空気を加熱するためのヒータと、ヒータで加熱された熱風を前記基板に吹き付けるために前記ケーシングの基板側位置に基板搬送方向に対し直角方向に掛け渡されると共に基板搬送方向に複数本配置されたパイプ状のノズルと、ヒータで加熱された熱風をノズルの両側の取入口に導く送風路と、前記ノズルから基板に吹き付けられた熱風を前記ノズルの間から前記ファンの吸込口に案内するために複数枚配設された熱風案内プレートとを備え、前記ファンからヒータを経由して加熱された熱風を、前記送風路を経て各ノズルの両側の取入口に導いた後、各ノズルから基板に吹き付け、更にこの熱風を前記ノズルの間から熱風案内プレートで案内してファンの吸込口へ吸い込む熱風循環経路が形成され、前記上下の熱風加熱ユニットのケーシングのそれぞれにおける基板搬送方向の前後端部には、前記ケーシング内の熱風を外部へ漏らさずに前記ファンの吸込口に導くための熱風吸引部を設けた熱風加熱装置であって、パイプ状のノズルは、その長さ方向に、前記基板に向けて熱風を吹き付けるためのスリットが形成され、パイプ状のノズルの内部には、ノズルの両側より中央部に向けて次第に高くなる複数の整流プレートを、熱風の流れる方向に対して略直角向きにほぼ等間隔に配設し、ノズル内を通過する熱風の一部を前記各整流プレートによってせき止めて、スリットから熱風を基板に向けて均等に噴き出す構成としたことを特徴としている。
【００１４】
上記目的を達成するために、本願の第２発明の熱風加熱装置は、基板を搬送する搬送面を中央にして、その上下に複数組の熱風加熱ユニットがそれぞれ配置され、前記上下の熱風加熱ユニットのそれぞれのケーシング内には、空気を循環送風するためのファンと、送風される空気を加熱するためのヒータと、ヒータで加熱された熱風を前記基板に吹き付けるために前記ケーシングの基板側位置に基板搬送方向に対し直角方向に掛け渡されると共に基板搬送方向に複数本配置されたパイプ状のノズルと、ヒータで加熱された熱風をノズルの両側の取入口に導く送風路と、前記ノズルから基板に吹き付けられた熱風を前記ノズルの間から前記ファンの吸込口に案内するために複数枚配設された熱風案内プレートとを備え、前記ファンからヒータを経由して加熱された熱風を、前記送風路を経て各ノズルの両側の取入口に導いた後、各ノズルから基板に吹き付け、更にこの熱風を前記ノズルの間から熱風案内プレートで案内してファンの吸込口へ吸い込む熱風循環経路が形成され、前記上下の熱風加熱ユニットのケーシングのそれぞれにおける基板搬送方向の前後端部には、前記ケーシング内の熱風を外部へ漏らさずに前記ファンの吸込口に導くための熱風吸引部を設けた熱風加熱装置であって、基板搬送面より下側の熱風加熱ユニットにおいて、その内部のノズルの下側には、下側の熱風加熱ユニットのファン及びヒータを停止させたときに、上側の熱風加熱ユニットのノズルから噴き出されて基板搬送面より下方に流れた熱風が反転して上昇するのを阻止するための平板形状の上昇阻止プレートが配設されていることを特徴としている。
【００１５】
上記目的を達成するために、本願の第３発明の熱風加熱装置は、基板を搬送する搬送面を中央にして、その上下に複数組の熱風加熱ユニットがそれぞれ配置され、前記上下の熱風加熱ユニットのそれぞれのケーシング内には、空気を循環送風するためのファンと、送風される空気を加熱するためのヒータと、ヒータで加熱された熱風を前記基板に吹き付けるために前記ケーシングの基板側位置に基板搬送方向に対し直角方向に掛け渡されると共に基板搬送方向に複数本配置されたパイプ状のノズルと、ヒータで加熱された熱風をノズルの両側の取入口に導く送風路と、前記ノズルから基板に吹き付けられた熱風を前記ノズルの間から前記ファンの吸込口に案内するために複数枚配設された熱風案内プレートとを備え、前記ファンからヒータを経由して加熱された熱風を、前記送風路を経て各ノズルの両側の取入口に導いた後、各ノズルから基板に吹き付け、更にこの熱風を前記ノズルの間から熱風案内プレートで案内してファンの吸込口へ吸い込む熱風循環経路が形成され、前記上下の熱風加熱ユニットのケーシングのそれぞれにおける基板搬送方向の前後端部には、前記ケーシング内の熱風を外部へ漏らさずに前記ファンの吸込口に導くための熱風吸引部を設けた熱風加熱装置であって、基板搬送面より下側の熱風加熱ユニットにおいて、その内部のノズルの下面は、下側の熱風加熱ユニットのファン及びヒータを停止させたときに、上側の熱風加熱ユニットのノズルから噴き出されて基板搬送面より下方に流れた熱風が反転して上昇するのを阻止するために平坦面に形成されていることを特徴としている。
【００１６】
【００１７】
【００１８】
【００１９】
本願の第 1 〜第 3発明の熱風加熱装置によると、熱風加熱ユニットのケーシング内からケーシング外へ流出しようとする熱風をケーシングの基板搬送方向の前後端部に設けた熱風吸引部で吸引して回収することによって、上下左右の熱風加熱ユニット間の熱風の干渉を最小限に抑え、各熱風加熱ユニット内の温度を設定温度に安定させることができる。又上下左右の熱風加熱ユニットのケーシング内の熱風循環経路を循環する熱風が接触し混合することがないので、各熱風加熱ユニットの温度をそれぞれの設定温度に保つことができる。
【００２０】
また熱風案内プレートによって、ノズルから吹き出した熱風を効率良く再度ファンの吸込口に回収して循環使用することができるので、ケーシング内に熱風の淀みや渦が発生する部分がなくなるので、温度のばらつきの少ない均一な温度の雰囲気をつくりだすことができると共に、熱効率を向上させることができる。
【００２１】
更に、熱風加熱ユニットのケーシングの基板搬送方向の前後端部から外部へ流出しようとする熱風は熱風吸引部でケーシング内へ引き戻され、更に、ケーシングの前面板及び後面板の先端が基板搬送面に近接している結果、ケーシングの外側の空気をこの熱風吸引部で吸引することが少なくなるので、ケーシング内の熱風循環経路内の循環風量の均衡を保つことができる。
【００２２】
また、本願の第 1 発明によると、パイプ状のノズルの左右両側から中央部分に向かって流れる熱風は、ノズルの中央部に向けてほぼ等間隔に配設され、ノズルの両側より中央部に向けて次第に高くなる複数の整流プレートに当たってその一部がせき止められ、スリットから基板に向けて均等に吹き付けられることになる。このように複数の整流プレートをノズル内に配設したことによって、ノズルから基板に向けてばらつきが少ないほぼ均等な風量で熱風を吹き付けることができる。
【００２３】
本願の第２、第３発明によると、フロー法における基板上面に熱硬化性樹脂を硬化させて電子部品を固定する際に、下側熱風加熱ユニットのファン及びヒータを停止させて使用するとき、上側の熱風加熱ユニットのノズルから噴き出されて基板搬送面より下方に流れた熱風が反転して上昇しようとすると、この熱風が平板状の上昇阻止プレートや平坦面に形成されたノズル下面によってその上昇が阻止されることによって、基板の下面に対して熱風が当たるのを阻止できて、熱風による基板の下面への加熱を極力小さくできる。
【００２４】
従って、熱硬化性接着剤を硬化させる基板の上面は熱風によって強制的に加熱され、一方基板の下面は、自然対流による加熱のみとなるために、基板の上下両面に温度差を付けることができ、これによって基板の下面に装着されたリード付き部品の温度上昇を抑えることができる。
【００２５】
【発明の実施の形態】
以下、本発明に係る熱風加熱装置の実施の形態について、図を参照しつつ説明する。
【００２６】
図１〜図３は本発明の第１の実施形態の熱風加熱装置を示す。
【００２７】
本実施形態の熱風加熱装置では、図１に示すように、プリント基板（基板）１は搬送装置２によって矢印Ａの方向へ搬送される。この搬送装置２の基板搬送面１３を中央にして、その上下に熱風加熱ユニット８ａ〜８ｃ、９ａ〜９ｃが配置され、さらにその下流側には、プリント基板搬送面１３を中央にしてその上下に冷却ユニット１０、１１が配置されており、それぞれの運転を制御することによって、リフロー半田付けやフロー半田の場合の接着剤の硬化のいずれでも行なうことができるようになっている。
【００２８】
プリント基板搬送面１３の上下の熱風加熱ユニット８ａ〜８ｃ、９ａ〜９ｃはいずれも構成が同じであるので、ここでは図２〜図５に基づいて最上流側の熱風加熱ユニット８ａ、９ａの構成を例に挙げて説明する。
【００２９】
上側の熱風加熱ユニット８ａは、図２、図３、図５に示すように構成されている。熱風加熱ユニット８ａのケーシング１２は、頂板７２ａ、前面板７２ｂ、後面板７２ｃ、左側面板７２ｄ、右側面板７２ｅからなる底面開放の直方体形状の外装ケース７２を有すると共に、その内方側に位置する天井板７０ａ、左内側板７０ｂ、右内側板７０ｃ、左底面板７０ｄ、右底面板７０ｅからなる横断面ハット形状の内装ケース７０を有している。前記外装ケース７２と内装ケース７０とが組み合わされて、図５に示すように、横断面（基板搬送方向に対し垂直な断面）が門型となる送風路空間１５が形成されている。この送風路空間１５は上部空間１５ａ、左下側空間１５ｂ、右下側空間１５ｃからなる。又前記内装ケース７０に囲まれるようにして、底面が開放された凹空間１４がケーシング１２内方に形成されている。なお、前記送風路空間１５および凹空間１４は、共に基板搬送方向の前後端が前記前面板７２ｂ、後面板７２ｃによって閉塞されている。
【００３０】
前記送風路空間１５の上部空間１５ａの中央には、空気を循環送風するためのファン２０が、前記頂板７２ａに支持されて配置されている。このファン２０は前記頂板７２ａ上に配置したモータ３０によって回転駆動される。又前記上部空間１５ａには、左右１対のヒータ２２、２２が配置され、ファン２０から遠心方向（横方向）に突き出された空気を加熱するように構成されている。加熱された空気（熱風）は送風路空間１５の左右下方の空間、すなわち左下側空間１５ｂ及び右下側空間１５ｃに送られる。
【００３１】
ケーシング１２の凹空間１４内の下端近傍には、左右方向（基板搬送方向に対し直角方向）に掛け渡された複数本の断面円形パイプからなるノズル１７、１７…が前後方向（基板搬送方向）に等間隔で配置されている。ノズル１７の両側の取入口１７ａ、１７ｂは前記左内側板７０ｂ及び右内側板７０ｃに接続され、前記左下側空間１５ｂ及び右下側空間１５ｃにそれぞれ連通している。又ノズル１７の下面にはその長さ方向に、基板１に向けて熱風を吹き付けるためのスリット１８が形成されている。更に、図５に示すように、ノズル１７の内部には、その両側取入口１７ａ、１７ｂより中央部に向けて次第に高くなる複数の整流プレート２９、２９、…を、熱風の流れる方向に対して略直角向きにほぼ等間隔に配設し、ノズル１７内を通過する熱風の一部を前記各整流プレート２９によってせき止めて、スリット１８から熱風を基板１に向けて均等に噴き出しうるように構成している。
【００３２】
前記ヒータ２２を介してファン２０から送られてきた熱風は、前記送風路空間１５によって構成される送風路を経て各ノズル１７の両側の取入口１７ａ、１７ｂに達してノズル１７内に導入され、次いで上述のように各ノズル１７のスリット１８を通過して、基板１に吹き付けられ、基板１を加熱する。
【００３３】
前記凹空間１４内には、図３に示すように、基板１に吹き付けられた熱風を前記ノズル１７、１７…の間から受け入れ、前記ファン２０の吸込口６０に導くための複数枚の熱風案内プレート２５、２５、…が設けられている。前記吸込口６０は前記天井板７０ａの中央に開設されている。又前記熱風案内プレート２５、２５、…は、図３に示すような断面形状をしており、プレート間間隔が上方に向け漸次縮小するようになっている。
【００３４】
前記熱風案内プレート２５、２５、…の内、最も前側に位置するものは前側の熱風吸引部２７ａの内板２５ａを兼ねており、その断面形状は、前記前面板７２ｂ及び天井板７０ａに沿うように屈曲した形状となっている。前記内板２５ａと前記前面板７２ｂとの間に形成される前側の熱風吸引部２７ａは、ケーシング１２内の熱風を外部に漏らさず、前記ファン吸込口６０に導くために設けられたものである。そして熱風の外部への漏出を防ぐため、前面板７２ｂの下端は基板搬送面１３に近接し、内板２５ａの下端は前記前面板７２ｂの下端に対して段差ｈをもって基板搬送面１３から若干離れた位置にあるように構成している。前記熱風案内プレート２５、２５、…の内、最も後側に位置するものは後側の熱風吸引部２７ｂの内板２５ｂを兼ねており、前記内板２５ａと同様にその断面形状は、前記後面板７２ｃ及び天井板７０ａに沿うように屈曲した形状となっている。前記内板２５ｂと前記後面板７２ｃとの間に形成される後側の熱風吸引部２７ｂは、前側の熱風吸引部２７ａと同様に、ケーシング１２内の熱風を外部に漏らさず、前記ファン吸込口６０に導くために設けられたものであり、又そのために後面板７２ｃの下端は基板搬送面１３に近接し、内板２５ｂの下端は前記後面板７２ｃの下端に対して段差ｈをもって基板搬送面１３から若干離れた位置にあるように構成されたものである。
【００３５】
下側の熱風加熱ユニット９ａは、図３に示すように基本的には上側の熱風加熱ユニット８ａと同様に構成され、両者は上下対称構造となるように構成されている。しかし次の２点において下側の熱風加熱ユニット９ａは、上側のそれ８ａと異なる構成を有している。
【００３６】
第１点は、下側の熱風加熱ユニット９ａ内のノズル１７の下側に、図３に示すように、下側の熱風加熱ユニット９ａのファン２０及びヒータ２２を停止させたときに、上側の熱風加熱ユニット８ａのノズル１７から噴き出されて基板搬送面１３より下方に流れた熱風が反転して上昇するのを阻止するための平板形状の上昇阻止プレート２８が配設されている点である。
【００３７】
この上昇阻止プレート２８を設ける代わりに、図４に示すように、前記ノズル１７の下面を、平坦面１７ｃに形成して、同様の作用を営ませるようにしてもよい。
【００３８】
第２点は、下側の熱風加熱ユニット９ａの頂板７２ａに冷却ファン２６を設け、ケーシング１２内を循環する熱風を間接的に冷却するようにしている点である。
【００３９】
以下、上記構成の熱風加熱装置における上下すべての熱風加熱ユニット８ａ〜８ｃ、９ａ〜９ｃを作動させたときの作用について説明する。
【００４０】
熱風加熱ユニット８ａ〜８ｃ、９ａ〜９ｃの駆動モータ３０を駆動してファン２０を回転駆動すると、ケーシング１２のファン吸込口６０の付近が負圧になり、搬送装置２の搬送面１３の付近の空気が、ノズル１７の間に形成される空間を介して熱風案内プレート２５、２５、…に沿って前記吸込口６０からファン２０に吸い込まれる。
【００４１】
ファン２０に吸い込まれた空気は、ファン２０によって送風路空間１５の上部空間１５ａに吐き出され、ヒータ２２、２２で加熱されて送風路空間１５の左右の下側空間１５ｂ、１５ｃに送風され、更に各ノズル１７に送風される。ここで、ノズル１７を形成するパイプの両取入口１７ａ、１７ｂから中央部分に向かって流れる熱風は、ノズル１７の中央部に向けてほぼ等間隔に配設され、高さが次第に高くなる複数の整流プレート２９、２９、…に当たってその一部がせき止められ、スリット１８から搬送装置２の搬送面１３や、この部分を通過するプリント基板１の上面又は下面に熱風がほぼ均等に吹き付けられる。
【００４２】
更に、熱風加熱ユニット８ａ〜８ｃ、９ａ〜９ｃのケーシング１２内からケーシング１２外へ流出しようとする熱風をケーシング１２のプリント基板搬送面側前後端部に設けた熱風吸引部２７ａ、２７ｂで吸引して回収することによって、各熱風加熱ユニット８ａ〜８ｃ、９ａ〜９ｃ間の熱風の干渉を最小限に抑えることができ、且つ熱効率が良くてそれぞれの熱風加熱ユニット８ａ〜８ｃ、９ａ〜９ｃ内を設定温度に安定させることができて、各ケーシング１２内の温度を所定温度にコントロールできる。
【００４３】
次に、フロー半田付けの接着剤硬化のために熱風加熱装置を用いる場合についての作用につき説明する。このとき、上側の熱風加熱ユニット８ａ〜８ｃのみを作動させ、下側の熱風加熱ユニット９ａ〜９ｃは停止させる。上側の熱風加熱ユニット８ａ〜８ｃの熱風の循環はすでに説明したものと同様である。この際、プリント基板１の搬送面１３の下側に配設された熱風加熱ユニット９ａ〜９ｃのノズル１７の下面に設けられた上昇阻止プレート２８によって、プリント基板１の下面に向けて上昇する熱風が阻止されて、この熱風は下側の熱風加熱ユニット９ａ〜９ｃのケーシング１２内の熱風案内プレート２５に沿ってファン吸込口６０に流れ込む。
【００４４】
これにより、上側の熱風加熱ユニット８ａ〜８ｃのノズル１７から吹き出されて下側の熱風加熱ユニット９ａ〜９ｃ内に入り込んだ熱風のはね返りがプリント基板１の下面を加熱する強制対流として働かない。従ってプリント基板１の下面の熱風加熱ユニット９ａ〜９ｃはファン２０及びヒータ２２、２２を停止させることで、熱硬化性接着剤の硬化時にプリント基板１の上下両面に温度差をつけることができる。
【００４５】
また、下側の加熱ユニット９ａ〜９ｃには、ケーシング１２の内部を循環する熱風を間接的に冷却するためにファン２６を設けているために、ケーシング１２が冷却され内部の熱が放出される。このようなファン２６を設けていない場合には、下側のヒータ２２、２２及びファン２０を停止させたのみでは温度コントロールできなくなり、時間経過と共に、下側のケーシング１２内の温度が上昇してしまう。ここで、ファン２６を設けることで、下側のケーシング１２内の温度を所定の低い温度にコントロールできる。
【００４６】
次に、上記接着剤硬化のために熱風加熱装置を用いる場合の具体例を説明する。
【００４７】
プリント基板１としては、図６に示すようにプリント基板１の上面に耐熱温度の比較的高いフラットパッケージＩＣ３０ａ〜３０ｃを接着剤で仮接着し、下面に耐熱温度の低いリード付き部品である電解コンデンサ３１を搭載したものを使用した。
【００４８】
上側の熱風加熱ユニット８ａは、熱風循環で加熱して熱硬化性接着剤を硬化させ、下側の熱風加熱ユニット９ａは、熱風循環を行わずに停止させている状態にした。
【００４９】
フラットパッケージＩＣ３０ａ〜３０ｃを接着剤で仮接着した側のプリント基板１の表面温度と、フラットパッケージＩＣの温度３３と、電解コンデンサ３１の温度３４のそれぞれの温度プロファイルを図７に示す。
【００５０】
図７から分かるように、接着剤塗布面のプリント基板１の表面温度３２は約１５０℃に、またフラットパッケージＩＣ３０ａ〜３０ｃの温度３３は約１３５℃と、接着剤塗布面のプリント基板１等は接着剤の硬化温度である１３０℃以上の温度に加熱できた。他方、プリント基板１の電解コンデンサ３１の温度３４は、電解コンデンサ３１の耐熱温度より低い１００℃以下の温度にすることができた。
【００５１】
【発明の効果】
以上のように本発明の熱風加熱装置によると、搬送装置の搬送面に配設され、電子部品を実装したプリント基板の上下両面から効率良く熱風を供給でき、しかも、熱風をケーシング内で良好に循環できて熱効率が良く、プリント基板に吹き付けられる熱風の温度のばらつきを最小限に抑え、この温度を効率良くコントロールできる。
【００５２】
更に、熱風発生装置のケーシングの基板搬送方向の前後端部に熱風吸引部を設けることで、ケーシング外に流出する熱風の量及びケーシング外から流入する空気の量を最小にすることができ、各ケーシング内の熱風の温度を、それぞれの設定温度に効率良くコントロールでき、しかもヒータの消費電力を少なくできる。
【図面の簡単な説明】
【図１】本発明の実施の形態の熱風加熱装置の外観を示す斜視図である。
【図２】実施形態の熱風加熱装置の上側の熱風加熱ユニットの一部切り欠き斜視図である。
【図３】実施形態の熱風加熱装置の上下一対の熱風加熱ユニットの部分断面図である。
【図４】下側の熱風加熱ユニットにおけるノズルの変形例を示す断面図である。
【図５】ノズル内の整流プレートの構造を示す説明図である。
【図６】実施形態で使用する基板の一例を示す斜視図である。
【図７】実施形態における温度プロファイルの説明図である。
【図８】従来のリフロー装置の一例を示す概略縦断面図である。
【符号の説明】
１基板
２搬送装置
８ａ〜８ｃ熱風加熱ユニット
９ａ〜９ｃ熱風加熱ユニット
１３基板搬送面
１５送風路空間
１７ノズル
１７ａ、１７ｂ取入口
１７ｃ平坦面
１８スリット
２０ファン
２２ヒータ
２５熱風案内プレート
２５ａ、２５ｂ内板
２６ファン
２７ａ、２７ｂ熱風吸引部
２８上昇阻止プレート
６０ファン吸込口
７２ｂ前面板
７２ｃ後面板[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a hot-air heating device used for reflow soldering an electronic component to a printed circuit board or for curing a thermosetting adhesive during flow soldering.
[0002]
[Prior art]
Conventionally, a reflow method and a flow method have been used as methods for soldering surface-mounted components to a printed circuit board.
[0003]
  In the reflow method, a solder paste is applied to a printed circuit board by printing or the like, an electronic component is mounted thereon, and the printed circuit board in this state is heated to melt and solder the solder paste.
[0004]
  In addition, the surface mounting component flow method applies an adhesive to a printed circuit board, mounts electronic components on the printed circuit board, cures the adhesive, turns the printed circuit board over, and places the printed circuit board in a jet-type solder bath. It is a method of soldering by soaking. In this case, since components with leads are often mounted on the printed circuit board, it is necessary to make the temperature on the side with the components with leads as low as possible for heating at the time of curing the adhesive. Therefore, in the hot-air heating device for printed circuit boards, the temperature of the adhesive-coated surface of the printed circuit board can be heated to the curing temperature of the adhesive, for example, 130 ° C. or higher. It is required that the temperature be lower than the heat resistant temperature of 100 ° C., for example.
[0005]
  Therefore, reflow heating (reflow method) and adhesive curing heating (flow method) used different equipment, but reflow heating (reflow method) and adhesive heating (flow method) are possible with the same equipment. Equipment requirements have emerged, and as a result, various heating devices have been developed.
[0006]
  An example is shown in FIG. The printed circuit board 1 is transported in the direction of arrow A by the transport device 2 and passes through the three sets of heating units 3 a, 3 b, 3 c of the furnace 3. Inside the furnace 3, the air fed into the furnace 3 as shown by the arrow a is blown out from the jet nozzle 4 as shown by the arrow b, and a part of the air passes through the arrow c and passes through the exhaust port 5. The air is exhausted as indicated by an arrow d, and the remaining air is circulated inside the furnace 3.
[0007]
  At the time of reflow soldering, the inside of the furnace 3 is heated with infrared rays by the panel heaters 6a, 6b, 6c and 7a, 7b, 7c, and is agitated by the air from the ejection nozzle 4 to achieve uniform heating of the printed circuit board 1. Yes.
[0008]
  When the adhesive is cured by flow soldering, the upper panel heater 7a, 7b, 7c and the air flow from the ejection nozzle 4 are turned off, and the upper panel heater is exhausted from the exhaust port 5 as indicated by the arrow d. Heat only 6a, 6b, 6c. In this way, a method has been developed that reduces the ambient temperature in the furnace 3 and keeps the bottom surface temperature of the printed circuit board 1 low.
[0009]
[Problems to be solved by the invention]
  Recently, there has been a demand for a temperature difference between the surface opposite to the soldering surface of the printed circuit board even during reflow heating, but the soldering surface of the printed circuit board is opposite to the soldering surface. If infrared heating is used as a hot air heating device to create a temperature difference with the side surface, the temperature difference within the same board or between components due to the difference in infrared absorption between the printed circuit board and electronic components, or the difference in heat capacity There has been a problem that the temperature difference of.
[0010]
  Further, in the conventional heating device, since a part of the hot air is exhausted from the exhaust port 5, the thermal efficiency is poor, and the temperature in the furnace 3 cannot be accurately controlled. There was a problem that variations occurred.
[0011]
  Further, the one shown in FIG. 8 includes three sets of heating units 3a, 3b, and 3c. However, there is mutual heat influence between the heating units 3a, 3b, and 3c, and each heating unit 3a, 3b, 3c There was a problem that it was difficult to control the temperature.
[0012]
  The present invention solves the above-mentioned conventional problems, is arranged on the conveyance surface of the conveyance device, can efficiently supply hot air from both the upper and lower surfaces of the printed circuit board on which electronic components are mounted, and circulates the hot air well in the casing. An object of the present invention is to provide a hot air heating apparatus that is capable of being thermally efficient, minimizing variations in temperature of hot air blown onto a printed circuit board, and capable of efficiently controlling this temperature.
[0013]
[Means for Solving the Problems]
  To achieve the above objective,No. of this application 1In the hot air heating device of the invention, a plurality of sets of hot air heating units are respectively arranged above and below the transport surface for transporting the substrate, and air is circulated and blown into the casings of the upper and lower hot air heating units. A fan for heating, a heater for heating the air to be blown, and a substrate side position of the casing in a direction perpendicular to the substrate transport direction in order to blow hot air heated by the heater onto the substrate A plurality of pipe-shaped nozzles arranged in the substrate transport direction, a blowing path for guiding hot air heated by the heater to intakes on both sides of the nozzle, and hot air blown to the substrate from the nozzle from between the nozzles A plurality of hot air guide plates arranged to guide the air to the fan inlet, and the hot air heated from the fan via a heater After being led to the intakes on both sides of each nozzle, a hot air circulation path is formed in which the hot air is blown onto the substrate from each nozzle, and further guided by the hot air guide plate from between the nozzles and sucked into the fan inlet. The front and rear end portions of the upper and lower hot air heating unit casings in the substrate transport direction are each provided with a hot air suction portion for guiding the hot air in the casing to the suction port of the fan without leaking outside.In the hot air heating device, a pipe-like nozzle is formed with a slit in the length direction for blowing hot air toward the substrate. Inside the pipe-like nozzle, a central portion is formed from both sides of the nozzle. A plurality of rectifying plates that gradually become higher are arranged at substantially equal intervals in a direction substantially perpendicular to the direction in which the hot air flows, and a portion of the hot air passing through the nozzle is blocked by the rectifying plates, and Hot air is blown evenly toward the substrateIt is characterized by that.
[0014]
  In order to achieve the above object, the hot air heating apparatus according to the second invention of the present application is characterized in that a plurality of sets of hot air heating units are arranged above and below the transport surface for transporting the substrate, respectively. In each of the casings, a fan for circulating and blowing air, a heater for heating the blown air, and hot air heated by the heater are blown to the substrate side position of the casing. A plurality of pipe-shaped nozzles that are stretched in a direction perpendicular to the substrate transport direction and arranged in the substrate transport direction, an air passage that guides hot air heated by the heater to intakes on both sides of the nozzle, and a substrate from the nozzle A plurality of hot air guide plates arranged to guide the hot air blown to the fan to the fan inlet from between the nozzles, the heater from the fan After the hot air heated via the air is guided to the intakes on both sides of each nozzle through the air passage, the hot air is blown onto the substrate from each nozzle, and further, the hot air is guided from between the nozzles by the hot air guide plate. The hot air circulation path for sucking into the suction port is formed at the front and rear ends of the upper and lower hot air heating unit casings in the substrate transport direction. Is a hot air heating device provided with a hot air suction part for guiding the hot air in the casing to the suction port of the fan without leaking outside, in the hot air heating unit below the substrate transfer surface, On the lower side of the nozzle, when the fan and heater of the lower hot air heating unit are stopped, the hot air blown from the nozzle of the upper hot air heating unit and flowing downward from the substrate transfer surface is reversed and rises. It is characterized in that a flat plate shaped rise prevention plate is provided for preventing this.
[0015]
  In order to achieve the above object, in the hot air heating apparatus of the third invention of the present application, a plurality of sets of hot air heating units are respectively arranged above and below the transport surface for transporting the substrate, and the upper and lower hot air heating units In each of the casings, a fan for circulating and blowing air, a heater for heating the blown air, and hot air heated by the heater are blown to the substrate side position of the casing. A plurality of pipe-shaped nozzles that are stretched in a direction perpendicular to the substrate transport direction and arranged in the substrate transport direction, an air passage that guides hot air heated by the heater to intakes on both sides of the nozzle, and a substrate from the nozzle A plurality of hot air guide plates arranged to guide the hot air blown to the fan to the fan inlet from between the nozzles, the heater from the fan After the heated hot air is guided to the intake ports on both sides of each nozzle through the air passage, the hot air is blown onto the substrate from each nozzle, and further, the hot air is guided from between the nozzles by the hot air guide plate. The hot air circulation path for sucking into the air inlet is formed, and the hot air in the casing is not leaked to the outside of the upper and lower ends of the upper and lower hot air heating units in the casing in the board conveying direction, and the fan air inlet is not leaked to the outside. A hot-air heating device provided with a hot-air suction unit for guiding, in the hot-air heating unit below the substrate transfer surface, the lower surface of the nozzle inside of the hot-air heating unit stops the fan and heater of the lower hot-air heating unit Sometimes it is formed on a flat surface to prevent the hot air blown out from the nozzle of the upper hot air heating unit and flowing downward from the substrate transfer surface from rising and reversing. It is characterized in Rukoto.
[0016]
[0017]
[0018]
[0019]
  BookNo. of wish 1 No. ThreeAccording to the hot air heating device of the invention, the hot air that is about to flow out of the hot air heating unit from the casing to the outside of the casing is sucked and collected by the hot air suction portions provided at the front and rear ends of the casing in the substrate transport direction. The hot air interference between the hot air heating units can be minimized, and the temperature in each hot air heating unit can be stabilized at the set temperature. Moreover, since the hot air circulating through the hot air circulation path in the casing of the upper, lower, left and right hot air heating units does not contact and mix, the temperature of each hot air heating unit can be maintained at the set temperature.
[0020]
  In addition, the hot air guide plate allows the hot air blown from the nozzles to be efficiently recovered and circulated again to the fan suction port, so there is no stagnation or swirl of hot air in the casing. It is possible to create an atmosphere at a uniform temperature with less heat and improve thermal efficiency.
[0021]
  Furthermore, hot air that is about to flow out from the front and rear ends of the casing of the hot air heating unit casing to the outside is drawn back into the casing by the hot air suction section, and the front and rear tips of the casing are brought to the substrate transport surface. As a result of being close to each other, the air outside the casing is less likely to be sucked by the hot air sucking portion, so that the balance of the circulating air volume in the hot air circulation path in the casing can be maintained.
[0022]
  In addition, 1 According to the inventionThe hot air flowing from the left and right sides of the pipe-shaped nozzle toward the central part is arranged at almost equal intervals toward the central part of the nozzle and hits a plurality of rectifying plates that gradually increase from both sides of the nozzle toward the central part. A part is blocked and sprayed evenly from the slit toward the substrate. By arranging a plurality of rectifying plates in the nozzle in this way, hot air can be blown with a substantially uniform air volume with little variation from the nozzle toward the substrate.
[0023]
  According to the second and third inventions of the present application,When fixing the electronic components by curing the thermosetting resin on the upper surface of the substrate in the flow method, when the fan and heater of the lower hot air heating unit are stopped and used, it is ejected from the nozzle of the upper hot air heating unit. When the hot air that has flowed downward from the substrate conveying surface is reversed and rises, the hot air is prevented from rising by a flat plate-like rise prevention plate or a nozzle lower surface formed on a flat surface. Therefore, it is possible to prevent the hot air from hitting the substrate, and the heating of the lower surface of the substrate by the hot air can be minimized.
[0024]
  Therefore, the upper surface of the substrate for curing the thermosetting adhesive is forcibly heated by hot air, while the lower surface of the substrate is only heated by natural convection, so that a temperature difference can be created between the upper and lower surfaces of the substrate. As a result, the temperature rise of the leaded parts mounted on the lower surface of the substrate can be suppressed.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, an embodiment of a hot air heating device according to the present invention will be described with reference to the drawings.
[0026]
  1 to 3 show a hot air heating apparatus according to a first embodiment of the present invention.
[0027]
  In the hot air heating device of the present embodiment, the printed circuit board (substrate) 1 is transported in the direction of arrow A by the transport device 2 as shown in FIG. Hot air heating units 8a to 8c and 9a to 9c are arranged above and below the substrate conveying surface 13 of the conveying device 2, and further on the downstream side thereof with the printed board conveying surface 13 as the center. Cooling units 10 and 11 are arranged, and by controlling the respective operations, either reflow soldering or curing of the adhesive in the case of flow soldering can be performed.
[0028]
  Since the hot air heating units 8a to 8c and 9a to 9c above and below the printed circuit board transport surface 13 have the same configuration, the structure of the hot air heating units 8a and 9a on the most upstream side is here based on FIGS. Will be described as an example.
[0029]
  The upper hot air heating unit 8a is configured as shown in FIG. 2, FIG. 3, and FIG. The casing 12 of the hot air heating unit 8a has a rectangular parallelepiped outer case 72 having an open bottom surface, which includes a top plate 72a, a front plate 72b, a rear plate 72c, a left side plate 72d, and a right side plate 72e, and a ceiling located on the inner side thereof. An interior case 70 having a hat-shaped cross section made up of a plate 70a, a left inner plate 70b, a right inner plate 70c, a left bottom plate 70d, and a right bottom plate 70e is provided. As shown in FIG. 5, the outer case 72 and the inner case 70 are combined to form an air passage space 15 whose cross section (cross section perpendicular to the substrate transport direction) is a gate shape. The air passage space 15 includes an upper space 15a, a lower left space 15b, and a lower right space 15c. A recessed space 14 having an open bottom is formed in the casing 12 so as to be surrounded by the interior case 70. Note that both the air passage space 15 and the recessed space 14 are closed at the front and rear ends in the substrate transport direction by the front plate 72b and the rear plate 72c.
[0030]
  At the center of the upper space 15a of the air passage space 15, a fan 20 for circulating and blowing air is supported by the top plate 72a. The fan 20 is rotationally driven by a motor 30 disposed on the top plate 72a. In the upper space 15a, a pair of left and right heaters 22 and 22 are arranged so as to heat the air protruding from the fan 20 in the centrifugal direction (lateral direction). The heated air (hot air) is sent to the left and right lower spaces of the air passage space 15, that is, the lower left space 15b and the lower right space 15c.
[0031]
  In the vicinity of the lower end in the concave space 14 of the casing 12, nozzles 17, 17. Are arranged at equal intervals. The intake ports 17a and 17b on both sides of the nozzle 17 are connected to the left inner plate 70b and the right inner plate 70c, and communicate with the lower left space 15b and the lower right space 15c, respectively. A slit 18 for blowing hot air toward the substrate 1 is formed in the lower surface of the nozzle 17 in the length direction thereof. Further, as shown in FIG. 5, a plurality of rectifying plates 29, 29,... Gradually increasing from the both-side intake ports 17 a, 17 b toward the center portion are disposed in the nozzle 17 with respect to the direction in which the hot air flows. Arranged at substantially equal intervals in a substantially right angle direction, a part of the hot air passing through the nozzle 17 is blocked by the respective rectifying plates 29 so that the hot air can be uniformly ejected from the slit 18 toward the substrate 1. ing.
[0032]
  The hot air sent from the fan 20 via the heater 22 reaches the intakes 17a and 17b on both sides of each nozzle 17 through the air passage constituted by the air passage space 15, and is introduced into the nozzle 17. Next, as described above, it passes through the slit 18 of each nozzle 17 and is sprayed onto the substrate 1 to heat the substrate 1.
[0033]
  In the concave space 14, as shown in FIG. 3, a plurality of hot air guides for receiving the hot air blown to the substrate 1 from between the nozzles 17, 17... And guiding them to the suction port 60 of the fan 20. Plates 25, 25,... Are provided. The suction port 60 is opened at the center of the ceiling board 70a. The hot air guide plates 25, 25,... Have a cross-sectional shape as shown in FIG. 3, and the distance between the plates gradually decreases upward.
[0034]
  Of the hot air guide plates 25, 25,..., The one located at the foremost side also serves as the inner plate 25a of the hot air suction portion 27a on the front side, and the cross-sectional shape thereof follows the front plate 72b and the ceiling plate 70a. It has a bent shape. The front hot air suction part 27a formed between the inner plate 25a and the front plate 72b is provided to guide the hot air in the casing 12 to the fan suction port 60 without leaking it to the outside. . In order to prevent leakage of hot air to the outside, the lower end of the front plate 72b is close to the substrate transfer surface 13, and the lower end of the inner plate 25a is slightly separated from the substrate transfer surface 13 with a step h with respect to the lower end of the front plate 72b. It is constituted so that it is in the position. Of the hot air guide plates 25, 25,..., The rearmost one also serves as the inner plate 25b of the hot air suction portion 27b on the rear side, and the cross-sectional shape of the hot air guide plates 25,. The shape is bent along the face plate 72c and the ceiling plate 70a. The rear hot air suction portion 27b formed between the inner plate 25b and the rear plate 72c does not leak the hot air in the casing 12 to the outside like the front hot air suction portion 27a. 60, the lower end of the rear plate 72c is close to the substrate transfer surface 13, and the lower end of the inner plate 25b has a step h with respect to the lower end of the rear plate 72c. It is configured to be at a position slightly away from 13.
[0035]
  As shown in FIG. 3, the lower hot air heating unit 9a is basically configured in the same manner as the upper hot air heating unit 8a, and both are configured to have a vertically symmetrical structure. However, in the following two points, the lower hot air heating unit 9a has a configuration different from that of the upper hot air heating unit 9a.
[0036]
  The first point is that when the fan 20 and the heater 22 of the lower hot air heating unit 9a are stopped as shown in FIG. 3 below the nozzle 17 in the lower hot air heating unit 9a, A flat plate-shaped rising prevention plate 28 is provided for preventing the hot air blown from the nozzle 17 of the hot air heating unit 8a and flowing downward from the substrate transfer surface 13 from being reversed and rising. .
[0037]
  Instead of providing the rising prevention plate 28, as shown in FIG. 4, the lower surface of the nozzle 17 may be formed on a flat surface 17c to perform the same operation.
[0038]
  The second point is that the cooling fan 26 is provided on the top plate 72a of the lower hot air heating unit 9a so that the hot air circulating in the casing 12 is indirectly cooled.
[0039]
  Hereinafter, an operation when all the upper and lower hot air heating units 8a to 8c and 9a to 9c in the hot air heating apparatus having the above configuration are operated will be described.
[0040]
  When the drive motor 30 of the hot air heating units 8 a to 8 c and 9 a to 9 c is driven to rotate the fan 20, the vicinity of the fan suction port 60 of the casing 12 becomes negative pressure, and the vicinity of the transport surface 13 of the transport device 2 is increased. Air is sucked into the fan 20 from the suction port 60 along the hot air guide plates 25, 25,... Through a space formed between the nozzles 17.
[0041]
  The air sucked into the fan 20 is discharged into the upper space 15a of the air passage space 15 by the fan 20, heated by the heaters 22 and 22, and blown to the left and right lower spaces 15b and 15c of the air passage space 15. Air is blown to each nozzle 17. Here, the hot air flowing from the two intake ports 17a and 17b of the pipes forming the nozzle 17 toward the central portion is arranged at substantially equal intervals toward the central portion of the nozzle 17, and a plurality of heights that gradually increase. A part of the rectifying plates 29, 29,... Is damped, and hot air is blown from the slit 18 to the conveying surface 13 of the conveying device 2 and the upper surface or the lower surface of the printed circuit board 1 that passes through this portion.
[0042]
  Further, hot air to flow out of the casing 12 of the hot air heating units 8a to 8c and 9a to 9c to the outside of the casing 12 is sucked by the hot air suction portions 27a and 27b provided at the front and rear ends of the casing 12 on the printed board conveyance surface side. By collecting the hot air heating units 8a to 8c and 9a to 9c, the hot air interference between the hot air heating units 8a to 8c and 9a to 9c can be minimized. The temperature can be stabilized at the set temperature, and the temperature in each casing 12 can be controlled to a predetermined temperature.
[0043]
  Next, the operation in the case of using a hot air heating device for curing the adhesive for flow soldering will be described. At this time, only the upper hot air heating units 8a to 8c are operated, and the lower hot air heating units 9a to 9c are stopped. The hot air circulation of the upper hot air heating units 8a to 8c is the same as that already described. At this time, the hot air rising toward the lower surface of the printed circuit board 1 by the ascent prevention plate 28 provided on the lower surface of the nozzle 17 of the hot air heating units 9 a to 9 c disposed below the conveying surface 13 of the printed circuit board 1. This hot air flows into the fan inlet 60 along the hot air guide plate 25 in the casing 12 of the lower hot air heating units 9a to 9c.
[0044]
  Thereby, the rebound of the hot air blown out from the nozzles 17 of the upper hot air heating units 8 a to 8 c and entered into the lower hot air heating units 9 a to 9 c does not work as forced convection for heating the lower surface of the printed circuit board 1. Therefore, the hot air heating units 9a to 9c on the lower surface of the printed circuit board 1 can make the temperature difference between the upper and lower surfaces of the printed circuit board 1 when the thermosetting adhesive is cured by stopping the fan 20 and the heaters 22 and 22.
[0045]
  In addition, since the lower heating units 9a to 9c are provided with a fan 26 for indirectly cooling the hot air circulating inside the casing 12, the casing 12 is cooled and the internal heat is released. . If such a fan 26 is not provided, the temperature cannot be controlled only by stopping the lower heaters 22 and 22 and the fan 20, and the temperature in the lower casing 12 increases with time. End up. Here, by providing the fan 26, the temperature in the lower casing 12 can be controlled to a predetermined low temperature.
[0046]
  Next, a specific example in the case of using a hot air heating device for curing the adhesive will be described.
[0047]
  As the printed circuit board 1, as shown in FIG. 6, a flat package IC 30a-30c having a relatively high heat resistance temperature is temporarily bonded to the upper surface of the printed circuit board 1 with an adhesive, and an electrolytic capacitor which is a leaded component having a low heat resistance temperature on the lower surface. The one equipped with 31 was used.
[0048]
  The upper hot air heating unit 8a was heated by hot air circulation to cure the thermosetting adhesive, and the lower hot air heating unit 9a was stopped without performing hot air circulation.
[0049]
  FIG. 7 shows temperature profiles of the surface temperature of the printed circuit board 1 on which the flat package ICs 30 a to 30 c are temporarily bonded with an adhesive, the temperature 33 of the flat package IC, and the temperature 34 of the electrolytic capacitor 31.
[0050]
  As can be seen from FIG. 7, the surface temperature 32 of the printed circuit board 1 on the adhesive application surface is about 150 ° C., and the temperature 33 of the flat package ICs 30a to 30c is about 135 ° C. The adhesive could be heated to a temperature of 130 ° C. or higher, which is the curing temperature of the adhesive. On the other hand, the temperature 34 of the electrolytic capacitor 31 of the printed circuit board 1 could be set to a temperature of 100 ° C. or lower which is lower than the heat resistance temperature of the electrolytic capacitor 31.
[0051]
【The invention's effect】
  As described above, according to the hot air heating device of the present invention, hot air can be efficiently supplied from the upper and lower surfaces of the printed circuit board mounted with the electronic components on the transfer surface of the transfer device. It can circulate and has high thermal efficiency, minimizing variations in the temperature of hot air blown to the printed circuit board, and can control this temperature efficiently.
[0052]
  Furthermore, by providing the hot air suction part at the front and rear ends of the casing of the hot air generating device in the substrate transport direction, the amount of hot air flowing out of the casing and the amount of air flowing out of the casing can be minimized. The temperature of the hot air in the casing can be efficiently controlled to each set temperature, and the power consumption of the heater can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an appearance of a hot air heating apparatus according to an embodiment of the present invention.
FIG. 2 is a partially cutaway perspective view of the hot air heating unit on the upper side of the hot air heating device of the embodiment.
FIG. 3 is a partial cross-sectional view of a pair of upper and lower hot air heating units of the hot air heating device of the embodiment.
FIG. 4 is a cross-sectional view showing a modified example of the nozzle in the lower hot air heating unit.
FIG. 5 is an explanatory view showing a structure of a rectifying plate in a nozzle.
FIG. 6 is a perspective view showing an example of a substrate used in the embodiment.
FIG. 7 is an explanatory diagram of a temperature profile in the embodiment.
FIG. 8 is a schematic longitudinal sectional view showing an example of a conventional reflow apparatus.
[Explanation of symbols]
  1 Substrate
  2 Transport device
  8a-8c Hot air heating unit
  9a-9c Hot air heating unit
  13 Board transfer surface
  15 Air duct space
  17 nozzles
  17a, 17b Intake
  17c flat surface
  18 slits
  20 fans
  22 Heater
  25 Hot air guide plate
  25a, 25b inner plate
  26 fans
  27a, 27b Hot air suction part
  28 Ascent prevention plate
  60 Fan inlet
  72b Front plate
  72c rear panel

Claims

A plurality of sets of hot air heating units are respectively disposed above and below the transport surface for transporting the substrate, and a fan for circulating and blowing air in each casing of the upper and lower hot air heating units; A heater for heating the air to be heated, and a plurality of wires arranged in a direction perpendicular to the substrate transport direction at the substrate side position of the casing in order to blow hot air heated by the heater onto the substrate The pipe-shaped nozzle, the air passage that guides the hot air heated by the heater to the inlets on both sides of the nozzle, and the hot air blown from the nozzle to the substrate is guided from between the nozzles to the suction port of the fan. A plurality of hot air guide plates are provided, and the hot air heated from the fan via the heater is passed through the air passages on both sides of each nozzle. After being led to the inlet, a hot air circulation path is formed in which the hot air is blown onto the substrate from each nozzle, and the hot air is guided from between the nozzles by the hot air guide plate and sucked into the fan inlet, and the casings of the upper and lower hot air heating units are formed. A hot air heating device provided with a hot air suction portion for guiding the hot air in the casing to the outside without leaking to the outside at the front and rear end portions in the substrate transport direction in each of the above ,
The pipe-shaped nozzle is formed with slits in the length direction for blowing hot air toward the substrate,
Inside the pipe-shaped nozzle, a plurality of rectifying plates that gradually increase from both sides of the nozzle toward the center are arranged at substantially equal intervals in a direction substantially perpendicular to the direction in which the hot air flows, and pass through the nozzle. The hot air heating apparatus is characterized in that a part of the hot air to be damped is blocked by each of the rectifying plates, and the hot air is uniformly ejected from the slit toward the substrate .

A plurality of sets of hot air heating units are respectively disposed above and below the transport surface for transporting the substrate, and a fan for circulating and blowing air in each casing of the upper and lower hot air heating units; A heater for heating the air to be heated, and a plurality of wires arranged in a direction perpendicular to the substrate transport direction at the substrate side position of the casing in order to blow hot air heated by the heater onto the substrate The pipe-shaped nozzle, the air passage that guides the hot air heated by the heater to the inlets on both sides of the nozzle, and the hot air blown from the nozzle to the substrate is guided from between the nozzles to the suction port of the fan. A plurality of hot air guide plates are provided, and the hot air heated from the fan via the heater is passed through the air passages on both sides of each nozzle. After that it led to the entrance, to the substrate from the nozzle
Further, a hot air circulation path is formed in which the hot air is further guided between the nozzles by the hot air guide plate and sucked into the fan inlet, and is formed at the front and rear end portions of the upper and lower hot air heating unit casings in the substrate transport direction. Is a hot air heating device provided with a hot air suction portion for guiding the hot air in the casing to the suction port of the fan without leaking outside,
In the hot air heating unit below the substrate transfer surface, the nozzles of the upper hot air heating unit are ejected to the lower side of the nozzle inside the hot air heating unit when the fan and heater of the lower hot air heating unit are stopped. thermal air heating device you characterized in that increase prevention plate of a flat plate shape is disposed to prevent the hot air flows downward from the substrate transport surface is raised inverted Te.

A plurality of sets of hot air heating units are respectively disposed above and below the transport surface for transporting the substrate, and a fan for circulating and blowing air in each casing of the upper and lower hot air heating units; A heater for heating the air to be heated, and a plurality of wires arranged in a direction perpendicular to the substrate transport direction at the substrate side position of the casing in order to blow hot air heated by the heater onto the substrate The pipe-shaped nozzle, the air passage that guides the hot air heated by the heater to the inlets on both sides of the nozzle, and the hot air blown from the nozzle to the substrate is guided from between the nozzles to the suction port of the fan. A plurality of hot air guide plates are provided, and the hot air heated from the fan via the heater is passed through the air passages on both sides of each nozzle. After being led to the inlet, a hot air circulation path is formed in which the hot air is blown onto the substrate from each nozzle, and the hot air is guided from between the nozzles by the hot air guide plate and sucked into the fan inlet, and the casings of the upper and lower hot air heating units are formed. the front and rear end portions of the substrate transfer direction in their respective of said a hot air heating device provided with a hot air suction portion for guiding the suction port of the fan hot air within the casing without leaking to the outside,
In the hot air heating unit below the substrate transfer surface, the lower surface of the nozzle inside the substrate is ejected from the nozzle of the upper hot air heating unit when the fan and heater of the lower hot air heating unit are stopped. thermal air heating device you characterized in that it is formed into a flat surface to the hot air flowing below the conveying surface is prevented from rising inverted.

A plurality of sets of hot air heating units are respectively disposed above and below the transport surface for transporting the substrate, and a fan for circulating and blowing air in each casing of the upper and lower hot air heating units; A heater for heating the air to be heated, and a plurality of wires arranged in a direction perpendicular to the substrate transport direction at the substrate side position of the casing in order to blow hot air heated by the heater onto the substrate a nozzle pipe-like, which is provided with a blowing path for guiding the hot air heated by the heater inlet on both sides of the nozzle, the hot air which is heated via heater from the fan, each nozzle through the air passage after that led to both sides of the inlet, blown from each nozzle to the substrate, is further hot air circulation path to suck the hot air to the suction port during or rough § down of the nozzle is formed, before The front and rear end portions of the substrate transport direction in each of the casings of the upper and lower hot-air heating unit, a hot air heating device provided with a hot air suction portion for guiding the suction inlet of the fan hot air within the casing without leaking to the outside There,
The pipe-shaped nozzle is formed with slits in the length direction for blowing hot air toward the substrate,
Inside the pipe-shaped nozzle, a plurality of rectifying plates that gradually increase from both sides of the nozzle toward the center are arranged at substantially equal intervals in a direction substantially perpendicular to the direction in which the hot air flows, and pass through the nozzle. The hot air heating apparatus is characterized in that a part of the hot air to be damped is blocked by each of the rectifying plates, and the hot air is uniformly ejected from the slit toward the substrate .

A plurality of sets of hot air heating units are respectively disposed above and below the transport surface for transporting the substrate, and a fan for circulating and blowing air in each casing of the upper and lower hot air heating units; A heater for heating the air to be heated, and a plurality of wires arranged in a direction perpendicular to the substrate transport direction at the substrate side position of the casing in order to blow hot air heated by the heater onto the substrate A pipe-shaped nozzle, and an air passage that guides the hot air heated by the heater to the intakes on both sides of the nozzle, and the hot air heated from the fan via the heater is passed through the air passage through each nozzle. Then, the air is blown to the substrate from each nozzle and this hot air is blown from between the nozzles.
A hot air circulation path for sucking into the air inlet of the fan is formed, and at the front and rear end portions of the upper and lower hot air heating units in the substrate transport direction, the hot air in the casing is not leaked to the outside without leaking to the outside. A hot air heating device provided with a hot air suction part for guiding to
In the hot air heating unit below the substrate transfer surface, the nozzles of the upper hot air heating unit are ejected to the lower side of the nozzle inside the hot air heating unit when the fan and heater of the lower hot air heating unit are stopped. thermal air heating device you characterized in that increase prevention plate of a flat plate shape is disposed to prevent the hot air flows downward from the substrate transport surface is raised inverted Te.

A plurality of sets of hot air heating units are respectively disposed above and below the transport surface for transporting the substrate, and a fan for circulating and blowing air in each casing of the upper and lower hot air heating units; A heater for heating the air to be heated, and a plurality of wires arranged in a direction perpendicular to the substrate transport direction at the substrate side position of the casing in order to blow hot air heated by the heater onto the substrate A pipe-shaped nozzle, and an air passage that guides the hot air heated by the heater to the intakes on both sides of the nozzle, and the hot air heated from the fan via the heater is passed through the air passage through each nozzle. Then, a hot air circulation path is formed in which the hot air is blown from the nozzles onto the substrate, and the hot air is sucked from between the nozzles into the fan inlet. A hot-air heating device provided with a hot-air suction unit for guiding the hot air in the casing to the suction port of the fan without leaking to the outside at the front and rear ends of the casings of the upper and lower hot-air heating units, respectively. There,
In the hot air heating unit below the substrate transfer surface, the lower surface of the nozzle inside the substrate is ejected from the nozzle of the upper hot air heating unit when the fan and heater of the lower hot air heating unit are stopped. thermal air heating device you characterized in that it is formed into a flat surface to the hot air flowing below the conveying surface is prevented from rising inverted.