JPH10109187A - Solder alloy for fitting electronic parts - Google Patents
Solder alloy for fitting electronic partsInfo
- Publication number
- JPH10109187A JPH10109187A JP28167496A JP28167496A JPH10109187A JP H10109187 A JPH10109187 A JP H10109187A JP 28167496 A JP28167496 A JP 28167496A JP 28167496 A JP28167496 A JP 28167496A JP H10109187 A JPH10109187 A JP H10109187A
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- Prior art keywords
- solder
- weight
- parts
- solder alloy
- balance
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Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は電子部品の実装に使
用するはんだ合金に関し、特に電子部品をリフロ−法に
より実装する場合に好適に使用されるものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder alloy used for mounting an electronic component, and more particularly, to a solder alloy suitably used for mounting an electronic component by a reflow method.
【0002】[0002]
【従来の技術】電子部品を回路基板に実装する場合、リ
フロ−法、すなわち、回路基板の所定位置に電子部品を
クリ−ムはんだ(はんだ粉末とフラックスとの混合物)
で粘着し、更に加熱炉に通してクリ−ムはんだを溶融
し、而るのち、はんだを冷却凝固させて電子部品を回路
基板に電気的・機械的に接合する方法を用いることがあ
り、このクリ−ムはんだのはんだ粉末には、伝統的にP
b−Sn共晶はんだが使用されてきた。このPb−Sn
共晶では、固相線温度と液相線温度とが一致するから、
融点に達すると固相から液相に即時に移行する。上記の
リフロ−法実装においては、電子部品の加熱の不均一が
避けられず、電子部品の片サイド電極のクリ−ムはんだ
が先に融点に達して液相化され、この際電子部品の他サ
イド電極のクリ−ムはんだが固相のままである状態が生
じ、片サイド電極のクリ−ムはんだの液相化による表面
張力で電子部品が起立されて他サイド電極が浮き上がり
(いわゆる、マンハッタン現象)、はんだ付け不良が発
生することがある。2. Description of the Related Art When electronic parts are mounted on a circuit board, a reflow method is used, that is, the electronic parts are cream soldered at a predetermined position on the circuit board (a mixture of solder powder and flux).
In some cases, the solder paste is melted by passing it through a heating furnace to melt the cream solder, and then the solder is cooled and solidified to electrically and mechanically join the electronic component to the circuit board. Traditionally, solder powder for cream solder has a P
b-Sn eutectic solder has been used. This Pb-Sn
In eutectic, the solidus temperature and liquidus temperature match, so
When the melting point is reached, there is an immediate transition from the solid phase to the liquid phase. In the above-mentioned reflow mounting, uneven heating of the electronic component is unavoidable, and the cream solder on one side electrode of the electronic component first reaches the melting point and is liquefied. The state where the cream solder of the side electrode remains in a solid phase occurs, the electronic component is raised by the surface tension due to the liquid phase of the cream solder of the one side electrode, and the other side electrode is lifted up (the so-called Manhattan phenomenon). ), Defective soldering may occur.
【0003】而るに、固相線温度と液相線温度との間に
差があるはんだ合金を、その温度差を上記の不均一温度
差に応じて設定して使用すれば、電子部品の上記片サイ
ド電極側が固相線温度と液相線温度との中間温度になっ
てクリ−ムはんだが半溶融状態(固相と液相との混在相
状態)となり、他サイド電極側のクリ−ムはんだがまだ
固相状態であっても、半溶融状態での表面張力が小さい
ために電子部品の起立を防止することが可能となり、更
に片サイド電極側が液相線温度を越えて液相状態とな
り、他サイド電極側のクリ−ムはんだがまだ半溶融状態
であっても、液相状態と半溶融状態での表面張力の差が
小さいために、電子部品の起立を防止することが可能と
なる。[0003] If a solder alloy having a difference between the solidus temperature and the liquidus temperature is used by setting the temperature difference in accordance with the above-mentioned non-uniform temperature difference, the use of a solder alloy can be improved. The above-mentioned one side electrode side is at an intermediate temperature between the solidus temperature and the liquidus temperature, so that the cream solder is in a semi-molten state (a mixed phase state of the solid phase and the liquid phase), and the other side electrode is a clear solder. Even if the solder is still in the solid state, the surface tension in the semi-molten state is small, so it is possible to prevent the electronic components from standing up. Thus, even if the cream solder on the other side electrode side is still in a semi-molten state, the difference in surface tension between the liquid phase state and the semi-molten state is small, so that it is possible to prevent the electronic component from rising. Become.
【0004】そこで、液相線温度と固相線温度とに差を
もたせてマンハッタン現象を防止することを企図して、
JIS Z 3282−1986でSn43PbBi14
(Sn43重量%、Bi14重量%、残部Pbであり、
固相線温度135℃、液相線温度165℃)が規格さ
れ、更に、Sn46PbBi8(固相線温度175℃、
液相線温度190℃)やSn57PbBi3(固相線温
度175℃、液相線温度185℃)も公知である。[0004] In view of the above, in order to prevent the Manhattan phenomenon by giving a difference between the liquidus temperature and the solidus temperature,
According to JIS Z 3282-1986, Sn43PbBi14
(43% by weight of Sn, 14% by weight of Bi, the balance Pb,
The solidus temperature is 135 ° C, the liquidus temperature is 165 ° C), and Sn46PbBi8 (solidus temperature 175 ° C,
Liquidus temperature 190 ° C) and Sn57PbBi3 (solidus temperature 175 ° C, liquidus temperature 185 ° C) are also known.
【0005】[0005]
【発明が解決しようとする課題】ところで、近来、電子
部品の複合化、高機能化、表面実装の高密度化が加速さ
れ、電子回路基板の発熱量が増し、通電ヒ−トサイクル
に基づきはんだ付け部が受ける繰返し熱応力がますます
厳しくなりつつあり、より優れた耐熱疲労特性が要求さ
れている。しかしながら、上記のSn−Pb−Bi系は
んだ合金では、溶融液相が冷却されて半溶融状態を通過
する際にボイドが形成され易く、またSnやPbにBi
が溶け込んで固溶体が形成され易いために、Pb−Sn
共晶はんだに較べ機械的強度が低く、上記耐熱疲労性の
向上を望み難い。従来、Sn−Pb−Bi系はんだ合金
をベ−スにしてCuを0.2重量%以下添加した電子部
品用はんだ合金が公知である(特公平1−24599号
公報)。In recent years, electronic components have become more complex, more sophisticated, and surface-mounting has been accelerated, the amount of heat generated by the electronic circuit board has been increased, and soldering has been performed based on the current heat cycle. The repetitive thermal stress applied to the attachment portion is becoming increasingly severe, and there is a demand for better thermal fatigue resistance. However, in the above-mentioned Sn-Pb-Bi-based solder alloy, voids are easily formed when the molten liquid phase is cooled and passes through a semi-molten state, and Bi is formed in Sn or Pb.
Dissolves easily to form a solid solution, so that Pb-Sn
The mechanical strength is lower than that of eutectic solder, and it is difficult to expect the above-mentioned improvement in thermal fatigue resistance. 2. Description of the Related Art Conventionally, there has been known a solder alloy for electronic components in which Cu is added in an amount of 0.2% by weight or less based on a Sn-Pb-Bi-based solder alloy (Japanese Patent Publication No. 24-5999).
【0006】しかしながら、本発明者において、マンハ
ッタン現象抑制作用を維持しつつ耐熱疲労特性の向上を
達成すべく鋭意検討したところ、CuとSbとを特定の
割合で添加することにより、上記のCu単独添加では達
成できない飛躍的な耐熱疲労性の向上を得ることができ
ることを知った。本発明の目的は、上記予想外の実験結
果に基づき、Sn−Pb−Bi系はんだ合金のマンハッ
タン現象抑制作用を充分に維持しつつ耐熱疲労特性の飛
躍的向上を達成することにある。However, the inventor of the present invention has made intensive studies to achieve the improvement of the thermal fatigue resistance while maintaining the Manhattan phenomenon suppressing action. By adding Cu and Sb at a specific ratio, the above-mentioned Cu alone is removed. It has been found that a remarkable improvement in thermal fatigue resistance, which cannot be achieved by addition, can be obtained. An object of the present invention is to achieve a dramatic improvement in thermal fatigue resistance while sufficiently maintaining the Manhattan phenomenon suppressing effect of a Sn-Pb-Bi-based solder alloy based on the above-mentioned unexpected experimental results.
【0007】[0007]
【課題を解決するための手段】本発明に係る電子部品実
装用はんだ合金は、Sn40〜70重量%、Bi2.5
〜15.0重量%、残部がPbのSn−Pb−Bi系は
んだ合金100重量部にCu0.3〜2.0重量部とS
b0.1〜2.0重量部、更にAg0.5〜3.5重量
部とが添加されていることを特徴とする構成であり、ま
た更に、PまたはGaを0.5重量部以下とが添加する
ことができる。本発明は、Sn40〜70重量%、Bi
2.5〜15.0重量%、残部がPbのSn−Pb−B
i系はんだ合金をベ−スにCuとSb、更にAg、また
更には必要に応じPまたはGaを特定量添加することに
より、Sn−Pb−Bi系はんだ合金のマンハッタン現
象抑制作用を充分に維持しつつ耐熱疲労性を飛躍的に向
上させ得るものである。The solder alloy for mounting electronic parts according to the present invention comprises 40 to 70% by weight of Sn and Bi2.5.
0.3 to 2.0 parts by weight of Cu and 100 parts by weight of Sn-Pb-Bi based solder alloy of Pb
b 0.1 to 2.0 parts by weight and further 0.5 to 3.5 parts by weight of Ag are added, and further 0.5 parts by weight or less of P or Ga is added. Can be added. In the present invention, Sn is 40 to 70% by weight, Bi
2.5-15.0% by weight, the balance being Sn-Pb-B with Pb
By adding a specific amount of Cu and Sb, further Ag and, if necessary, P or Ga to the base of the i-based solder alloy, the action of suppressing the Manhattan phenomenon of the Sn-Pb-Bi-based solder alloy is sufficiently maintained. It is possible to dramatically improve the thermal fatigue resistance while performing the same.
【0008】本発明において、Snを40〜70重量%
とする理由は、40重量%未満でははんだ付けの作業性
が悪くなるばかりか、合金強度及び接合強度が著しく低
くなり、接合信頼性が損なわれ、また、液相線温度が高
くなる結果、はんだ付け時での基板や表面実装部品への
熱衝撃が過酷になり、他方、70重量%を越えると、コ
ストアップとなるばかりか、前記と同様に液相線温度が
高くなる結果、はんだ付け時での基板や表面実装部品へ
の熱衝撃が過酷になるからである。本発明において、B
iの添加は固相線温度と液相線温度とに差をもたせてマ
ンハッタン現象を抑制するためであり、その添加量を
2.5〜15.0重量%とする理由は、2.5重量%未
満ではマンハッタン現象を満足に抑制し難く、他方1
5.0重量%を越えると、伸びが減少し脆くなって機械
的強度が低下し、接合信頼性を保証し難くなるからであ
る。In the present invention, Sn is contained in an amount of 40 to 70% by weight.
The reason is that if the content is less than 40% by weight, not only the workability of soldering is deteriorated, but also the alloy strength and the joining strength are remarkably reduced, the joining reliability is impaired, and the liquidus temperature is increased. The thermal shock to the substrate and the surface-mounted components during mounting becomes severe. On the other hand, if it exceeds 70% by weight, not only does the cost increase, but also the liquidus temperature increases as described above. This is because the thermal shock to the substrate and the surface mount component in the above becomes severe. In the present invention, B
The addition of i is for giving a difference between the solidus temperature and the liquidus temperature to suppress the Manhattan phenomenon, and the reason for adding 2.5 to 15.0% by weight is that 2.5% by weight is used. %, It is difficult to satisfactorily suppress the Manhattan phenomenon.
If the content exceeds 5.0% by weight, the elongation is reduced, the material becomes brittle, the mechanical strength is reduced, and it becomes difficult to guarantee the joining reliability.
【0009】本発明において、CuとSbとの添加はマ
ンハッタン現象抑制作用を充分に維持しつつ耐熱疲労性
を飛躍的に向上させためであり、CuまたはSbの単独
では不適当であり、それらの添加量をCu0.3〜2.
0重量部とSb0.1〜2.0重量部とする理由は、こ
れらの範囲内で耐熱疲労特性の飛躍的向上が達成でき、
しかもCu2.0重量部以上やSb2.0重量部以上で
は、液相線温度が高くなって、はんだ付け時での基板や
表面実装電子部品への熱的衝撃が相当過酷になるからで
ある。本発明において、Agの添加は、被接合部材がA
gである場合に、Ag食われ(Agがはんだ中に拡散す
ること、溶食とも称されている)による接合不良が懸念
されるため、これを防止することにある。その添加量を
0.5〜3.5重量部とした理由は、0.5重量部以下
ではAg食われを満足に抑制し難く、他方、3.5重量
部を越えるとコスト高になるばかりか、液相線温度が高
くなって、はんだ付け時での基板や表面実装電子部品へ
の熱的衝撃が過酷になるからである。In the present invention, the addition of Cu and Sb is intended to dramatically improve the thermal fatigue resistance while sufficiently maintaining the Manhattan phenomenon-suppressing action. Cu or Sb alone is not suitable for use alone. The added amount is Cu 0.3-2.
The reason for setting 0 parts by weight and 0.1 to 2.0 parts by weight of Sb is that within these ranges, a dramatic improvement in thermal fatigue resistance can be achieved,
In addition, if the Cu content is 2.0 parts by weight or more or the Sb content is 2.0 parts by weight or more, the liquidus temperature becomes high, and the thermal shock to the substrate and the surface-mounted electronic components during soldering becomes considerably severe. In the present invention, the addition of Ag causes the member to be joined to be A
In the case of g, there is a concern about poor bonding due to Ag erosion (Ag diffuses into the solder, also referred to as erosion). The reason for setting the addition amount to 0.5 to 3.5 parts by weight is that if it is less than 0.5 parts by weight, it is difficult to satisfactorily suppress Ag erosion, while if it exceeds 3.5 parts by weight, the cost increases. Alternatively, the liquidus temperature increases, and the thermal shock to the substrate and the surface-mounted electronic components during soldering becomes severe.
【0010】本発明において、PまたはGaの添加は、
上記添加したCuやSbによるはんだ合金の濡れ性低下
を補償すると共にはんだ合金溶融下での酸化を抑制し当
該酸化物の巻き込みによるはんだ接合部の強度低下を防
止するためであり、その添加量を0.5重量部以下とす
る理由は、0.5重量部を越えるとはんだ合金の脆弱化
が招来されるからである。In the present invention, the addition of P or Ga is
This is to compensate for the decrease in the wettability of the solder alloy due to the added Cu or Sb and to suppress the oxidation under the melting of the solder alloy to prevent the strength of the solder joint portion from being reduced by the inclusion of the oxide. The reason for setting the content to 0.5 part by weight or less is that if the content exceeds 0.5 part by weight, the solder alloy will become brittle.
【0011】はんだ合金においては、添加元素以外の成
分を不純物として含有するのが通常であり、JIS Z
−3282−1986−表3に規定されているA級の化
学成分に従い、本発明に係るはんだ合金においても、Z
nを0.003重量%以下、Feを0.03重量%以
下、Alを0.005重量%以下、Asを0.03重量
%以下、Cdを0.005重量%以下の範囲で含有する
ことが許容される。[0011] Solder alloys usually contain components other than additive elements as impurities.
According to the class A chemical composition specified in Table 3, the solder alloy according to the present invention also has a Z content.
n: 0.003% by weight or less, Fe: 0.03% by weight or less, Al: 0.005% by weight or less, As: 0.03% by weight or less, Cd: 0.005% by weight or less Is acceptable.
【0012】[0012]
【発明の実施の形態】本発明において、べ−スのSn−
Pb−Bi系はんだ合金としては、例えば、日本工業規
格で規定された、Sn43重量%、Bi14重量%、
残部Pb(固相線温度135℃、液相線温度165
℃)、または、公知のSn46重量%、Bi8、残部
Pb(固相線温度175℃、液相線温度190℃)S
n57、Bi3、残部Pb(固相線温度175℃、液相
線温度185℃)等を使用できる。DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the base Sn-
Examples of the Pb-Bi-based solder alloy include Sn 43% by weight, Bi 14% by weight, and
The balance Pb (solidus temperature 135 ° C, liquidus temperature 165
° C) or known Sn 46% by weight, Bi8, balance Pb (solidus temperature 175 ° C, liquidus temperature 190 ° C)
n57, Bi3, and the balance Pb (solidus temperature 175 ° C., liquidus temperature 185 ° C.) and the like can be used.
【0013】本発明に係る電子部品実装用はんだ合金
は、リフロ−法におけるクリ−ムはんだとして好適に使
用される。この場合、粉末はんだは、例えば、遠心噴霧
法により得ることができ、その粒直径は通常65〜20
μmであり、フラックスの組成は、ロジン20〜60重
量%、活性剤0.2〜5重量%、チクソ剤3〜20重量
部%、残部溶剤であり、クリ−ムはんだの組成は、通常
粉末はんだ85〜93重量%、残部フラックスである。
リフロ−法により表面実装を行うには、回路基板の電子
部品搭載予定箇所にクリ−ムはんだを印刷し、更に、電
子部品をそのクリ−ムはんだの粘着力で仮固定し、次い
で、はんだ合金の液相線温度よりも数十度高い温度の加
熱炉、例えば赤外線加熱炉等に通してクリ−ムはんだを
溶融し、而るのち、はんだを冷却凝固させ、最終的にフ
ラックス残渣の洗浄を行い、これにて実装を終了する。The solder alloy for mounting electronic parts according to the present invention is suitably used as a cream solder in a reflow method. In this case, the powder solder can be obtained by, for example, a centrifugal spray method, and the particle diameter thereof is usually 65 to 20.
The composition of the flux is 20 to 60% by weight of rosin, 0.2 to 5% by weight of an activator, 3 to 20% by weight of a thixotropic agent, and the remainder is a solvent. The solder is 85 to 93% by weight, and the balance is flux.
In order to perform surface mounting by the reflow method, a cream solder is printed on a place where electronic components are to be mounted on a circuit board, and the electronic components are temporarily fixed by the adhesive strength of the cream solder. Through a heating furnace having a temperature several tens of degrees higher than the liquidus temperature, for example, an infrared heating furnace, to melt the cream solder, then cool and solidify the solder, and finally wash the flux residue. Done, and this ends the implementation.
【0014】本発明に係るはんだ合金においては、Cu
及びSbの添加量がSn−Pb−Bi系はんだ合金のマ
ンハッタン現象抑制作用を充分に維持できる範囲内であ
り、上記加熱の不均一のために、電子部品の片サイド電
極側が固相線温度と液相線温度との中間温度になってク
リ−ムはんだが半溶融状態(固相と液相との混在相状
態)となり、他サイド電極側のクリ−ムはんだにおいて
はまだ固相状態であっても、半溶融状態での表面張力が
小さいために電子部品の起立をよく防止でき、更に片サ
イド電極側が液相線温度を越えて液相状態となり、他サ
イド電極側のクリ−ムはんだにおいてはまだ半溶融状態
であっても、液相状態と半溶融状態での表面張力の差が
小さいために、電子部品の起立をよく防止できる。In the solder alloy according to the present invention, Cu
And the amount of Sb added is within a range that can sufficiently maintain the Manhattan phenomenon suppressing action of the Sn-Pb-Bi-based solder alloy. Due to the uneven heating, the one-side electrode side of the electronic component has a solidus temperature and a solidus temperature. When the temperature reaches an intermediate temperature from the liquidus temperature, the cream solder is in a semi-molten state (a mixed phase state of a solid phase and a liquid phase), and the cream solder on the other side electrode side is still in a solid phase state. However, since the surface tension in the semi-molten state is small, it is possible to prevent the electronic component from standing up well.In addition, one side electrode side exceeds the liquidus temperature and becomes in a liquid state, and the other side electrode side has cream solder. Even though is still in a semi-molten state, since the difference in surface tension between the liquid phase state and the semi-molten state is small, the electronic component can be prevented from standing up.
【0015】上記リフロ−法により実装された電子部品
のはんだ付け部の通電ヒ−トサイクルに起因する破壊
(クラックやしわの発生)のメカニズムは複雑であり、
はんだと基板や電子部品との熱膨張収縮係数の差やヤン
グ率の差や環境温度変化等に基づき熱応力が発生し、そ
の熱応力がはんだの破断強度に達したときに破断するこ
とを根拠にしてのはんだ合金の抗張力や伸び率の評価だ
けでは耐熱疲労特性の適確な把握は困難であり、適確な
把握のためには、はんだの濡れ状態や電極や導体とはん
だとの界面部分での合金層形成による機械的特性(組織
の強度、ヤング率、伸び率、熱膨張収縮係数等)の変化
を反映させることが妥当である。しかるに、次に述べる
接合強度は、はんだの濡れ状態と界面部分での合金層形
成による機械的特性の変化を充分に反映して耐熱疲労性
を評価できるものであり、この接合強度はつぎのように
して求められる。The mechanism of the destruction (cracks and wrinkles) caused by the heat cycle of the soldered portion of the electronic component mounted by the reflow method is complicated,
It is based on the fact that thermal stress is generated based on the difference in thermal expansion / contraction coefficient between the solder and the board or electronic component, the difference in Young's modulus, the change in environmental temperature, etc. It is difficult to accurately grasp the thermal fatigue properties only by evaluating the tensile strength and elongation percentage of the solder alloy, and it is difficult to accurately grasp the wettability of the solder and the interface between the electrode and conductor and the solder. It is appropriate to reflect changes in the mechanical properties (structure strength, Young's modulus, elongation, thermal expansion / shrinkage coefficient, etc.) due to the formation of the alloy layer in (1). However, the bonding strength described below can sufficiently evaluate the thermal fatigue resistance by sufficiently reflecting the change in mechanical properties due to the wet state of the solder and the formation of the alloy layer at the interface, and the bonding strength is as follows. Required.
【0016】すなわち、巾10mm、厚み0.5mmの
銅箔2枚をギャップを隔てて重ね、片端部にスペ−サを
挾着してギャップを0.5mmに設定し、この重ね銅箔
の他端部にフラックスを塗布した後、溶融はんだ浴に浸
漬して毛細管現象により溶融はんだをギャップ間に深さ
10mmになるように侵入させ、はんだの冷却凝固後、
スペ−サを外して銅箔をはんだの侵入端箇所で直角に外
側に曲げ、この曲げた両銅箔を引張り端子としてロ−ド
セル方式万能試験機を用い、引張り速度5mm/mi
n、温度20℃で破断するときの引張り応力(kgf/
mm2)を測定する。この接合強度によれば、はんだ合
金の抗張力や伸び率とは異なり、銅とはんだとの界面で
の金属学的反応による機械的強度の変化や濡れ性を反映
させることができ、はんだ付け部の耐熱疲労性を適確に
評価できる。而るに、本発明に係る実装においては、C
u0.3〜2.0重量部とSb0.1〜2.0重量部と
を添加しているために抜群に優れた接合強度を呈し、極
めて優れた耐熱疲労特性を保証できる。That is, two copper foils each having a width of 10 mm and a thickness of 0.5 mm are stacked with a gap therebetween, and a spacer is sandwiched at one end to set the gap to 0.5 mm. After applying the flux to the end, the molten solder is immersed in a molten solder bath to penetrate the molten solder to a depth of 10 mm between the gaps by capillary action, and after cooling and solidifying the solder,
After removing the spacer, the copper foil is bent outward at a right angle at the solder entry end, and the bent copper foils are used as tension terminals using a load cell universal testing machine at a pulling speed of 5 mm / mi.
n, tensile stress when breaking at a temperature of 20 ° C. (kgf /
mm 2 ). According to this joint strength, unlike the tensile strength and elongation of the solder alloy, it is possible to reflect the change in mechanical strength and wettability due to the metallurgical reaction at the interface between the copper and the solder, and Thermal fatigue resistance can be evaluated accurately. Thus, in the implementation according to the present invention, C
Since u is added in an amount of 0.3 to 2.0 parts by weight and Sb in an amount of 0.1 to 2.0 parts by weight, excellent bonding strength is exhibited, and extremely excellent thermal fatigue resistance can be guaranteed.
【0017】かかる耐熱疲労特性の保証は、機械的に脆
弱な固溶体の生成を抑制でき、ボイドの発生を排除で
き、かつ濡れ性に優れ、しかも電極や導体とはんだとの
界面部分での合金層形成による機械的特性(組織の強
度、ヤング率、伸び率、熱膨張収縮係数等)の異変をよ
く防止できた結果と推定される。なお、本発明に係る電
子部品用はんだ合金はリフロ−法に好適に使用される
が、フロ−法及びやに入りはんだとしても使用できる。[0017] The assurance of the thermal fatigue resistance is such that the formation of a mechanically fragile solid solution can be suppressed, the generation of voids can be eliminated, the wettability is excellent, and the alloy layer at the interface between the electrode or conductor and the solder can be prevented. This is presumed to be a result of preventing abnormal changes in mechanical properties (tissue strength, Young's modulus, elongation, thermal expansion / shrinkage coefficient, etc.) due to formation. Although the solder alloy for electronic parts according to the present invention is suitably used in the reflow method, it can also be used as a flow method and as a flux solder.
【0018】[0018]
【実施例】以下の実施例及び比較例において、クリ−ム
はんだのはんだ粉末には遠心噴霧法による粒直径63〜
38μmのものを使用し、フラックスには、ロジン5
0.0重量%、活性剤(シクロヘキシルアミン臭化水素
酸塩)1.0重量%、チクソ剤(水素添加ヒマシ油)
5.0重量%、残部溶剤(ブチルカルビト−ル)を使用
し、クリ−ムはんだの配合は、はんだ粉末90重量%、
残部フラックスとした。また、マンハッタン現象発生率
は、チップ寸法32mm×16mm×0.5mmのチッ
プ抵抗器をガラスエポキシ回路基板にクリ−ムはんだを
用いてリフロ−法により実装した試料1000箇から求
めた。更に、ヒ−トサイクル試験も上記と同様にして製
作した試料について行い、125℃で1時間加熱 、−
55℃で1時間冷却を1サイクルとして500サイクル
を課し、はんだ接合部にクラック、しわ、剥離等が発生
したものを不良とし、試料数は100箇とした。EXAMPLES In the following Examples and Comparative Examples, the solder powder of the cream solder had a grain diameter of 63 to 63 by a centrifugal spray method.
Use a 38μm one, and use rosin 5
0.0% by weight, activator (cyclohexylamine hydrobromide) 1.0% by weight, thixotropic agent (hydrogenated castor oil)
5.0% by weight, the balance solvent (butyl carbitol) was used, and the mixture of cream solder was 90% by weight of solder powder,
The remaining flux was used. The Manhattan phenomenon occurrence rate was determined from 1000 samples in which a chip resistor having a chip size of 32 mm × 16 mm × 0.5 mm was mounted on a glass epoxy circuit board by a reflow method using a cream solder. Further, a heat cycle test was performed on the sample manufactured in the same manner as above, and the sample was heated at 125 ° C. for 1 hour.
One cycle of cooling at 55 ° C. for 1 hour was applied, and 500 cycles were applied. A solder joint having cracks, wrinkles, peeling, etc. was regarded as defective, and the number of samples was 100.
【0019】〔実施例1〜8及び比較例1〜4〕べ−ス
のSn−Pb−Bi系はんだ合金に、Sn57重量%、
Bi3重量%、残部Pb(固相線温度175℃、液相線
温度185℃)を用いたものであり、使用したはんだ合
金の配合は表1(配合の単位は重量部)の通りである。
それぞれの接合強度(実施例1の接合強度を1として示
してある。実施例1の接合強度は、6.18kgf/m
m2)並びにヒ−トサイクル試験の結果は表1に示す通
りである。[Examples 1 to 8 and Comparative Examples 1 to 4] A Sn—Pb—Bi-based solder alloy based on
Bi 3% by weight and the balance Pb (solidus temperature 175 ° C., liquidus temperature 185 ° C.) are used, and the blending of the used solder alloy is as shown in Table 1 (the blending unit is part by weight).
Each bonding strength (the bonding strength of Example 1 is shown as 1. The bonding strength of Example 1 is 6.18 kgf / m.
m 2 ) and the results of the heat cycle test are shown in Table 1.
【0020】[0020]
【表1】 [Table 1]
【0021】表1から明らかな通り、実施例ではヒ−ト
サイクル試験の不良発生率が0%であり、比較例1や比
較例2との対比からこの効果がCuとSbとの相乗効果
によるものであることが推定できる。また、Cu0.3
重量部以下及びSb0.1重量部以下ではヒ−トサイク
ル試験の不良発生率を0にできず、更にCu2.0重量
部以上及びSb2.0重量部以上ではヒ−トサイクル試
験の不良発生率を0にできないことが比較例3、比較例
4から明らかであり、本発明におけるCu及びSbの添
加量限定の意義が確認できる。実施例が耐熱疲労性に優
れていることは、ヒ−トサイクル試験の不良発生率が0
で、かつ接合強度にも優れていることから裏付けられ
る。なお、Sn−Pb共晶はんだ合金についてのマンハ
ッタン現象発生率は15%〜20%であり、本発明によ
れば、べ−スのSn−Pb−Bi系はんだ合金のマンハ
ッタン現象抑制効果も充分に維持できることが表1から
確認できる。As is clear from Table 1, in the examples, the failure occurrence rate in the heat cycle test was 0%, and this effect was due to the synergistic effect of Cu and Sb from the comparison with Comparative Examples 1 and 2. Can be presumed. Also, Cu0.3
If the amount is less than 0.1 parts by weight and Sb is less than 0.1 part by weight, the failure rate of the heat cycle test cannot be made zero. It is evident from Comparative Examples 3 and 4 that it cannot be set to 0, and the significance of limiting the added amounts of Cu and Sb in the present invention can be confirmed. The excellent thermal fatigue resistance of the example means that the failure rate of the heat cycle test was 0%.
And excellent bonding strength. The Manhattan phenomenon occurrence rate of the Sn-Pb eutectic solder alloy is 15% to 20%, and according to the present invention, the Manhattan phenomenon suppression effect of the base Sn-Pb-Bi-based solder alloy is sufficiently improved. It can be confirmed from Table 1 that it can be maintained.
【0022】〔実施例9〜16〕べ−スのSn−Pb−
Bi系はんだ合金に、Sn46重量%、Bi8重量%、
残部Pb(固相線温度175℃、液相線温度190℃)
を用いたものであり、使用したはんだ合金の配合は表2
(配合の単位は重量部)の通りである。それぞれの接合
強度(実施例1の接合強度を1として示してある)並び
にヒ−トサイクル試験の結果は表2に示す通りである。Embodiments 9 to 16: Base Sn-Pb-
46% by weight of Sn, 8% by weight of Bi,
Remainder Pb (solidus temperature 175 ° C, liquidus temperature 190 ° C)
Table 2 shows the composition of the solder alloy used.
(The unit of blending is parts by weight). Table 2 shows the bonding strength (the bonding strength of Example 1 is shown as 1) and the results of the heat cycle test.
【0023】[0023]
【表2】 [Table 2]
【0024】〔実施例17〜24〕べ−スのSn−Pb
−Bi系はんだ合金に、Sn43重量%、Bi14重量
%、残部Pb(固相線温度135℃、液相線温度165
℃)を用いたものであり、使用したはんだ合金の配合は
表3(配合の単位は重量部)の通りである。それぞれの
接合強度(実施例1の接合強度を1として示してある)
並びにヒ−トサイクル試験の結果は表3に示す通りであ
る。[Embodiments 17 to 24] Base Sn-Pb
In the Bi-based solder alloy, 43% by weight of Sn, 14% by weight of Bi, and the balance Pb (solidus temperature 135 ° C, liquidus temperature 165)
° C), and the composition of the used solder alloy is as shown in Table 3 (the unit of the composition is parts by weight). Each bonding strength (the bonding strength of Example 1 is shown as 1)
The results of the heat cycle test are as shown in Table 3.
【0025】[0025]
【表3】 [Table 3]
【0026】[0026]
【発明の効果】本発明に係る電子部品用はんだ合金よれ
ば、Sn−Pb−Bi系はんだ合金のマンハッタン現象
抑制作用を充分に維持し得、かつ、Sn−Pb−Bi系
はんだ合金の耐熱疲労性に劣る不利をよく解消して耐熱
疲労特性の飛躍的向上を達成でき、電子部品実装時の不
良率を低減しつつ実装後での耐熱疲労に対する信頼性を
飛躍的に向上できる。According to the solder alloy for electronic parts according to the present invention, the effect of suppressing the Manhattan phenomenon of the Sn-Pb-Bi solder alloy can be sufficiently maintained, and the thermal fatigue of the Sn-Pb-Bi solder alloy can be maintained. It is possible to remarkably improve disadvantages in heat resistance by resolving disadvantageous inferiority, and to remarkably improve reliability against heat fatigue after mounting while reducing the failure rate at the time of mounting electronic components.
Claims (3)
5.0重量%、残部がPbのSn−Pb−Bi系はんだ
合金100重量部にCu0.3〜2.0重量部とSb
0.1〜2.0重量部とが添加されていることを特徴と
する電子部品実装用はんだ合金。1. 40 to 70% by weight of Sn, 2.5 to 1% of Bi
5.0% by weight, the balance being 0.3 to 2.0 parts by weight of Cu and 100 parts by weight of Sn-Pb-Bi-based solder alloy of Pb
A solder alloy for mounting electronic components, wherein 0.1 to 2.0 parts by weight is added.
5.0重量%、残部がPbのSn−Pb−Bi系はんだ
合金100重量部にCu0.3〜2.0重量部とSb
0.1〜2.0重量部とAg0.5〜3.5重量部とが
添加されていることを特徴とする電子部品実装用はんだ
合金。2. Sn 40 to 70% by weight, Bi 2.5 to 1
5.0% by weight, the balance being 0.3 to 2.0 parts by weight of Cu and 100 parts by weight of Sn-Pb-Bi-based solder alloy of Pb
A solder alloy for mounting electronic components, wherein 0.1 to 2.0 parts by weight and 0.5 to 3.5 parts by weight of Ag are added.
ている請求項1または2記載の電子部品実装用はんだ合
金。3. The solder alloy according to claim 1, wherein P or Ga is added in an amount of 0.5 part by weight or less.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28167496A JP3708252B2 (en) | 1996-10-02 | 1996-10-02 | Solder alloy powder for reflow mounting of electronic parts |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28167496A JP3708252B2 (en) | 1996-10-02 | 1996-10-02 | Solder alloy powder for reflow mounting of electronic parts |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH10109187A true JPH10109187A (en) | 1998-04-28 |
JP3708252B2 JP3708252B2 (en) | 2005-10-19 |
Family
ID=17642407
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP28167496A Expired - Fee Related JP3708252B2 (en) | 1996-10-02 | 1996-10-02 | Solder alloy powder for reflow mounting of electronic parts |
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Country | Link |
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JP (1) | JP3708252B2 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7097090B2 (en) * | 2000-11-21 | 2006-08-29 | Senju Metal Industry Co., Ltd. | Solder ball |
CN103075319A (en) * | 2011-10-25 | 2013-05-01 | 株式会社日立产机系统 | Water supply device and operation method of the same |
US11285569B2 (en) | 2003-04-25 | 2022-03-29 | Henkel Ag & Co. Kgaa | Soldering material based on Sn Ag and Cu |
-
1996
- 1996-10-02 JP JP28167496A patent/JP3708252B2/en not_active Expired - Fee Related
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7097090B2 (en) * | 2000-11-21 | 2006-08-29 | Senju Metal Industry Co., Ltd. | Solder ball |
US11285569B2 (en) | 2003-04-25 | 2022-03-29 | Henkel Ag & Co. Kgaa | Soldering material based on Sn Ag and Cu |
CN103075319A (en) * | 2011-10-25 | 2013-05-01 | 株式会社日立产机系统 | Water supply device and operation method of the same |
Also Published As
Publication number | Publication date |
---|---|
JP3708252B2 (en) | 2005-10-19 |
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