TWI550639B - Connecting wires for semiconductor devices - Google Patents

Connecting wires for semiconductor devices Download PDF

Info

Publication number
TWI550639B
TWI550639B TW104131499A TW104131499A TWI550639B TW I550639 B TWI550639 B TW I550639B TW 104131499 A TW104131499 A TW 104131499A TW 104131499 A TW104131499 A TW 104131499A TW I550639 B TWI550639 B TW I550639B
Authority
TW
Taiwan
Prior art keywords
wire
mass
bonding wire
bonding
concentration
Prior art date
Application number
TW104131499A
Other languages
Chinese (zh)
Other versions
TW201642279A (en
Inventor
Takashi Yamada
Daizo Oda
Teruo Haibara
Tomohiro Uno
Original Assignee
Nippon Micrometal Corp
Nippon Steel & Sumikin Mat Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to JP2015106368 priority Critical
Priority to TW104118466 priority
Application filed by Nippon Micrometal Corp, Nippon Steel & Sumikin Mat Co filed Critical Nippon Micrometal Corp
Priority to TW104131499A priority patent/TWI550639B/en
Application granted granted Critical
Publication of TWI550639B publication Critical patent/TWI550639B/en
Publication of TW201642279A publication Critical patent/TW201642279A/en

Links

Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L24/00Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/42Wire connectors; Manufacturing methods related thereto
    • H01L24/44Structure, shape, material or disposition of the wire connectors prior to the connecting process
    • H01L24/45Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/43Manufacturing methods
    • H01L2224/438Post-treatment of the connector
    • H01L2224/43848Thermal treatments, e.g. annealing, controlled cooling
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/44Structure, shape, material or disposition of the wire connectors prior to the connecting process
    • H01L2224/45Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/44Structure, shape, material or disposition of the wire connectors prior to the connecting process
    • H01L2224/45Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
    • H01L2224/45001Core members of the connector
    • H01L2224/45099Material
    • H01L2224/451Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
    • H01L2224/45138Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
    • H01L2224/45147Copper (Cu) as principal constituent
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/44Structure, shape, material or disposition of the wire connectors prior to the connecting process
    • H01L2224/45Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
    • H01L2224/4554Coating
    • H01L2224/45565Single coating layer
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/44Structure, shape, material or disposition of the wire connectors prior to the connecting process
    • H01L2224/45Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
    • H01L2224/4554Coating
    • H01L2224/4557Plural coating layers
    • H01L2224/45572Two-layer stack coating

Description

半導體裝置用接合導線 Bonding wire for semiconductor device
本發明係關於一種用於將半導體元件上之電極與外部引線等電路配線基板之配線加以連接的半導體裝置用接合導線。 The present invention relates to a bonding wire for a semiconductor device for connecting an electrode on a semiconductor element to a wiring of a circuit wiring board such as an external lead.
目前,作為將半導體元件上之電極與外部引線之間加以接合之半導體裝置用接合導線(以下稱為「接合導線」),主要使用線徑15~50μm左右之細線。接合導線之接合方法一般為超音波併用熱壓接方式,可使用通用接合裝置、使接合導線通過其內部而用於連接之毛細治具等。接合導線之接合製程係藉由如下方式完成,即,藉由電弧熱輸入將導線前端進行加熱熔融,藉由表面張力而形成球(FAB:Free Air Ball(無空氣球))後,將該球部壓接接合(以下稱為「球接合」)於在150~300℃之範圍內經加熱之半導體元件之電極上,繼而形成迴路後,對外部引線側之電極壓接接合(以下稱為「楔形接合」)導線部。關於作為接合導線之接合對象的半導體元件上之電極,一直採用使以Al為主體之合金於Si基板上成膜所得之電極構造、對外部引線側之電極實施鍍Ag或鍍Pd處理所得之電極構造等。 At present, as a bonding wire for a semiconductor device (hereinafter referred to as a "bonding wire") for bonding an electrode on a semiconductor element and an external lead, a thin wire having a wire diameter of about 15 to 50 μm is mainly used. The bonding method of the bonding wires is generally ultrasonic and is thermocompression bonding, and a universal bonding device, a capillary fixture for connecting the bonding wires through the inside thereof, and the like can be used. The bonding process of the bonding wires is performed by heating and melting the leading end of the wire by the arc heat input, forming a ball by the surface tension (FAB: Free Air Ball), and then the ball The crimp bonding (hereinafter referred to as "ball bonding") is performed on the electrode of the semiconductor element heated in the range of 150 to 300 ° C, and then the electrode is crimped to the external lead side (hereinafter referred to as "wedge" Join") wire section. The electrode on the semiconductor element to be bonded to the bonding wire is an electrode structure obtained by forming an alloy mainly composed of Al on the Si substrate, and an electrode obtained by performing Ag plating or Pd plating on the electrode on the external lead side. Construction, etc.
迄今為止,接合導線之材料係Au為主流,但以LSI(Large Scale Integration,大規模積體電路)用途為中心而逐漸用Cu代替Au。另一方面,近年來於電動汽車或油電混合車普及之背景下,於車載裝置用途中以Cu代替Au之需求亦提高。 In the past, the material of the bonding wire was mainly in the form of Au, but Cu was gradually replaced by Cu in the LSI (Large Scale Integration) application. On the other hand, in recent years, in the context of the widespread use of electric vehicles or hybrid vehicles, the demand for Cu to replace Au in in-vehicle applications has also increased.
關於Cu接合導線,已提出有使用高純度Cu(純度:99.99質量%以 上)者(例如專利文獻1)。Cu與Au相比有易被氧化之缺點,存在接合可靠性、球形成性、楔形接合性等較差之課題。作為防止Cu接合導線之表面氧化之方法,已提出有以Au、Ag、Pt、Pd、Ni、Co、Cr、Ti等金屬將Cu芯材表面被覆之構造(專利文獻2)。又,已提出有於Cu芯材表面上被覆Pd、並由Au、Ag、Cu或該等之合金將該表面被覆之構造(專利文獻3)。 Regarding Cu-bonded wires, it has been proposed to use high-purity Cu (purity: 99.99% by mass) The above (for example, Patent Document 1). Cu has a disadvantage of being easily oxidized compared with Au, and has problems such as poor bonding reliability, spherical formability, and wedge bondability. As a method of preventing oxidation of the surface of the Cu-bonded wire, a structure in which the surface of the Cu core material is coated with a metal such as Au, Ag, Pt, Pd, Ni, Co, Cr, or Ti has been proposed (Patent Document 2). Further, a structure in which Pd is coated on the surface of the Cu core material and the surface is covered with Au, Ag, Cu, or the like is proposed (Patent Document 3).
[先前技術文獻] [Previous Technical Literature] [專利文獻] [Patent Literature]
[專利文獻1]日本專利特開昭61-48543號公報 [Patent Document 1] Japanese Patent Laid-Open No. 61-48543
[專利文獻2]日本專利特開2005-167020號公報 [Patent Document 2] Japanese Patent Laid-Open Publication No. 2005-167020
[專利文獻3]日本專利特開2012-36490號公報 [Patent Document 3] Japanese Patent Laid-Open Publication No. 2012-36490
車載裝置與通常之電子機器相比,要求嚴酷之高溫高濕環境下之接合可靠性。尤其將導線之球部接合於電極上而形成之球接合部之接合壽命成為最大問題。關於對高溫高濕環境下之接合可靠性加以評價之方法,提出有若干方法,作為具代表性之評價法,有HAST(Highly Accelerated Temperature and Humidity Stress Test)(高溫高濕環境暴露試驗)。於藉由HAST對球接合部之接合可靠性進行評價之情形時,將評價用之球接合部暴露於溫度130℃、相對濕度85%之高溫高濕環境下,測定接合部之電阻值之經時變化,或測定球接合部之剪切強度之經時變化,藉此評價球接合部之接合壽命。近來,於此種條件下之HAST中逐漸要求100小時以上之接合壽命。 The in-vehicle device requires a joint reliability in a severe high-temperature and high-humidity environment as compared with a conventional electronic device. In particular, the bonding life of the ball joint formed by joining the ball portion of the wire to the electrode is the biggest problem. There are several methods for evaluating the joint reliability in a high-temperature and high-humidity environment. As a representative evaluation method, there is a HAST (Highly Accelerated Temperature and Humidity Stress Test). When the joint reliability of the ball joint portion is evaluated by HAST, the ball joint portion for evaluation is exposed to a high temperature and high humidity environment having a temperature of 130 ° C and a relative humidity of 85%, and the resistance value of the joint portion is measured. The change in time or the change in the shear strength of the ball joint portion was measured, thereby evaluating the joint life of the ball joint portion. Recently, the joint life of 100 hours or more has been gradually required in HAST under such conditions.
使用先前之具有Pd被覆層之Cu接合導線與純Al電極進行接合,第一接合設為球接合、第二接合設為楔形接合,以模塑樹脂加以密封後,進行上述HAST條件下之評價,結果存在球接合部之接合壽命未 達100小時之情況,得知車載裝置所要求之接合可靠性不充分。 Bonding with a pure Al electrode using a conventional Cu bonding wire having a Pd coating layer, the first bonding is a ball bonding, the second bonding is a wedge bonding, and after sealing with a molding resin, the evaluation under the HAST condition is performed. As a result, there is a joint life of the ball joint. In the case of 100 hours, it was found that the joint reliability required for the in-vehicle device was insufficient.
本發明之目的在於提供一種對表面具有Pd被覆層之Cu接合導線改善高溫高濕環境下之球接合部之接合可靠性而適於車載裝置的接合導線。 An object of the present invention is to provide a bonding wire suitable for an in-vehicle device in which a Cu bonding wire having a Pd coating layer on its surface is used to improve bonding reliability of a ball joint portion in a high-temperature and high-humidity environment.
即,本發明之要旨如下所述。 That is, the gist of the present invention is as follows.
(1)一種半導體裝置用接合導線,其係具有Cu合金芯材、與形成於上述Cu合金芯材之表面上之Pd被覆層者,其特徵在於: 上述接合導線包含選自As、Te、Sn、Sb、Bi、Se中之至少1種以上之元素,上述元素相對於導線整體之濃度合計為0.1~100質量ppm,Sn≦10質量ppm,Sb≦10質量ppm,Bi≦1質量ppm。 (1) A bonding wire for a semiconductor device comprising a Cu alloy core material and a Pd coating layer formed on a surface of the Cu alloy core material, wherein: The bonding wire includes at least one element selected from the group consisting of As, Te, Sn, Sb, Bi, and Se, and the total concentration of the element relative to the entire wire is 0.1 to 100 ppm by mass, and Sn ≦ 10 ppm by mass, Sb≦ 10 mass ppm, Bi≦1 mass ppm.
(2)如上述(1)記載之半導體裝置用接合導線,其特徵在於:選自As、Te、Sn、Sb、Bi、Se中之至少1種以上之元素相對於導線整體之濃度合計為1~100質量ppm。 (2) The bonding wire for a semiconductor device according to the above aspect (1), wherein a concentration of at least one element selected from the group consisting of As, Te, Sn, Sb, Bi, and Se is 1 in total with respect to the total concentration of the wire. ~100 mass ppm.
(3)如上述(1)或(2)記載之半導體裝置用接合導線,其特徵在於:上述Pd被覆層之厚度為0.015~0.150μm。 (3) The bonding wire for a semiconductor device according to the above aspect (1), wherein the thickness of the Pd coating layer is 0.015 to 0.150 μm.
(4)如上述(1)至(3)中任一項記載之半導體裝置用接合導線,其特徵在於:於上述Pd被覆層上進而具有包含Au與Pd之合金表皮層。 (4) The bonding wire for a semiconductor device according to any one of the above-mentioned (1), wherein the Pd coating layer further includes an alloy skin layer containing Au and Pd.
(5)如上述(4)記載之半導體裝置用接合導線,其特徵在於:上述包含Au與Pd之合金表皮層之厚度為0.0005~0.050μm。 (5) The bonding wire for a semiconductor device according to the above (4), wherein the thickness of the alloy skin layer containing Au and Pd is 0.0005 to 0.050 μm.
(6)如上述(1)至(5)中任一項記載之半導體裝置用接合導線,其特徵在於:上述接合導線進而包含選自Ni、Zn、Rh、In、Ir、Pt、Ga、Ge中之至少1種以上之元素,上述元素相對於導線整體之濃度分別為0.011~1.2質量%。 (6) The bonding wire for a semiconductor device according to any one of the above aspects, wherein the bonding wire further comprises a material selected from the group consisting of Ni, Zn, Rh, In, Ir, Pt, Ga, and Ge. At least one or more of the elements, the concentration of the element relative to the entire wire is 0.011 to 1.2% by mass.
(7)如上述(1)至(6)中任一項記載之半導體裝置用接合導線,其特徵在於:上述Cu合金芯材包含Pd,上述Cu合金芯材所含之Pd之濃度 為0.05~1.2質量%。 (7) The bonding wire for a semiconductor device according to any one of the above aspects, wherein the Cu alloy core material contains Pd, and the concentration of Pd contained in the Cu alloy core material is It is 0.05 to 1.2% by mass.
(8)如上述(1)至(7)中任一項記載之半導體裝置用接合導線,其特徵在於:上述接合導線進而包含選自B、P、Mg、Ca、La中之至少1種以上之元素,上述元素相對於導線整體之濃度分別為1~100質量ppm。 (8) The bonding wire for a semiconductor device according to any one of the above aspects, wherein the bonding wire further includes at least one selected from the group consisting of B, P, Mg, Ca, and La. The element is such that the concentration of the above element relative to the entire wire is 1 to 100 ppm by mass.
(9)如上述(1)至(8)中任一項記載之半導體裝置用接合導線,其特徵在於:於測定上述接合導線表面之結晶方位時之測定結果中,相對於上述接合導線長度方向而角度差為15度以下之結晶方位<111>之存在比率以面積率計為30~100%。 The bonding wire for a semiconductor device according to any one of the above aspects of the present invention, characterized in that, in the measurement result of measuring the crystal orientation of the surface of the bonding wire, the length of the bonding wire is opposite to the length of the bonding wire The ratio of the crystal orientation <111> having an angular difference of 15 degrees or less is 30 to 100% in terms of area ratio.
(10)如上述(1)至(9)中任一項記載之半導體裝置用接合導線,其特徵在於:於上述接合導線之最表面存在Cu。 The bonding wire for a semiconductor device according to any one of the above aspects of the present invention, wherein the bonding wire is provided on the outermost surface of the bonding wire.
根據本發明,於具有Cu合金芯材、與形成於Cu合金芯材之表面上之Pd被覆層的半導體裝置用接合導線中,接合導線含有合計0.1~100質量ppm之選自As、Te、Sn、Sb、Bi、Se中之至少1種以上之元素,藉此可延長高溫高濕環境下之球接合部之接合壽命,改善接合可靠性。 According to the present invention, in the bonding wire for a semiconductor device having a Cu alloy core material and a Pd coating layer formed on the surface of the Cu alloy core material, the bonding wires contain a total of 0.1 to 100 ppm by mass selected from As, Te, and Sn. At least one or more of Sb, Bi, and Se can extend the bonding life of the ball joint portion in a high-temperature and high-humidity environment, thereby improving the joint reliability.
本發明之接合導線為具有Cu合金芯材、與形成於上述Cu合金芯材之表面上之Pd被覆層的半導體裝置用接合導線,其中,接合導線含有合計0.1~100質量ppm之選自As、Te、Sn、Sb、Bi、Se中之至少1種以上之元素。具有該特定構成之本發明之接合導線可改善車載裝置所要求之高溫高濕環境下之球接合部之接合可靠性。 The bonding wire of the present invention is a bonding wire for a semiconductor device having a Cu alloy core material and a Pd coating layer formed on the surface of the Cu alloy core material, wherein the bonding wire contains a total of 0.1 to 100 mass ppm selected from As, At least one or more of Te, Sn, Sb, Bi, and Se. The bonding wire of the present invention having this specific configuration can improve the bonding reliability of the ball joint portion in the high temperature and high humidity environment required for the in-vehicle device.
詳細內容將於下文中進行說明,若使用本發明之接合導線藉由 電弧放電而形成球,則於接合導線熔融而凝固之過程中,於球表面形成Pd濃度高於球內部之合金層。若使用該球與Al電極進行接合並實施高溫高濕試驗,則接合界面上成為Pd濃化狀態。該Pd濃化而形成之濃化層可抑制高溫高濕試驗中之接合界面上之Cu、Al之擴散,降低易腐蝕性化合物之成長速度,顯著提高高溫高濕環境下之球接合部之接合可靠性。 The details will be explained below if the bonding wire of the present invention is used When the arc is formed to form a ball, an alloy layer having a Pd concentration higher than that inside the ball is formed on the surface of the ball during the melting and solidification of the bonding wire. When the ball is bonded to the Al electrode and the high-temperature and high-humidity test is performed, the Pd is concentrated in the joint interface. The concentrated layer formed by the concentration of Pd can suppress the diffusion of Cu and Al at the joint interface in the high-temperature and high-humidity test, reduce the growth rate of the corrosive compound, and significantly improve the bonding of the ball joint in the high-temperature and high-humidity environment. reliability.
又,形成於球表面之Pd濃度較高之合金層由於耐氧化性優異,故而可減少於球形成時球之形成位置相對於接合導線之中心而發生偏移等不良。 Further, since the alloy layer having a high Pd concentration formed on the surface of the ball is excellent in oxidation resistance, it is possible to reduce defects such as a shift in the position at which the ball is formed at the time of ball formation with respect to the center of the bonding wire.
就延長溫度130℃、相對濕度85%之高溫高濕環境下之球接合部之接合壽命,改善接合可靠性之觀點而言,選自As、Te、Sn、Sb、Bi、Se中之至少1種以上之元素相對於接合導線整體之濃度合計為0.1質量ppm以上,較佳為0.5質量ppm以上,更佳為1質量ppm以上,進而較佳為1.5質量ppm以上、2質量ppm以上、2.5質量ppm以上、或3質量ppm以上。 It is at least 1 selected from the group consisting of As, Te, Sn, Sb, Bi, and Se from the viewpoint of improving the bonding reliability of the ball joint portion in a high-temperature and high-humidity environment at a temperature of 130 ° C and a relative humidity of 85%. The total concentration of the above elements with respect to the entire bonding wire is 0.1 mass ppm or more, preferably 0.5 mass ppm or more, more preferably 1 mass ppm or more, further preferably 1.5 mass ppm or more, 2 mass ppm or more, 2.5 mass. More than ppm, or more than 3 ppm by mass.
作為半導體裝置之封裝材料之模塑樹脂(環氧樹脂)於其分子骨架中包含氯(Cl)。於作為HAST評價條件之130℃、相對濕度85%之高溫高濕環境下,分子骨架中之Cl發生水解而以氯化物離子(Cl-)之形式溶出。於將不具有被覆層之Cu接合導線接合於Al電極之情形時,若將Cu/Al接合界面置於高溫下,則Cu與Al相互擴散,最終形成作為金屬間化合物之Cu9Al4。Cu9Al4易受到鹵素之腐蝕,由自模塑樹脂中溶出之氯化物致使腐蝕進行,導致接合可靠性下降。於Cu導線具有Pd被覆層之情形時,Pd被覆Cu導線與Al電極之接合界面成為Cu/Pd濃化層/Al之構造,因此與不具有被覆層之Cu導線相比抑制Cu9Al4金屬間化合物之生成,但車載裝置所要求之高溫高濕環境下之接合可靠性並不充分。 A molding resin (epoxy resin) as an encapsulating material of a semiconductor device contains chlorine (Cl) in its molecular skeleton. Under a high-temperature and high-humidity environment of 130 ° C and a relative humidity of 85% as HAST evaluation conditions, Cl in the molecular skeleton is hydrolyzed and eluted as chloride ions (Cl - ). When a Cu bonding wire having no coating layer is bonded to an Al electrode, when the Cu/Al bonding interface is placed at a high temperature, Cu and Al are mutually diffused to form Cu 9 Al 4 as an intermetallic compound. Cu 9 Al 4 is susceptible to corrosion by halogen, and corrosion is caused by chloride eluted from the molded resin, resulting in a decrease in bonding reliability. In the case where the Cu wire has a Pd coating layer, the bonding interface between the Pd-coated Cu wire and the Al electrode becomes a Cu/Pd-concentrated layer/Al structure, and thus the Cu 9 Al 4 metal is suppressed as compared with the Cu wire without the coating layer. The formation of the inter-compound is not sufficient in the high-temperature and high-humidity environment required for the in-vehicle device.
相對於此,可認為若如本發明般Pd被覆Cu接合導線含有特定量之選自As、Te、Sn、Sb、Bi、Se中之至少1種以上之元素,則存在進一步抑制接合部中生成Cu9Al4金屬間化合物之傾向。推測若含有特定量之該等元素,則於形成球時,芯材之Cu與被覆層之Pd的界面張力降低,界面之潤濕性變良好,故球接合界面之Pd濃化更顯著地顯現。因此,利用Pd濃化層之Cu與Al之相互擴散抑制效果進一步增強,結果容易因Cl之作用而腐蝕之Cu9Al4之生成量變少,球接合部之高溫高濕環境下之接合可靠性顯著提高。 On the other hand, when the Pd-coated Cu-bonding wire contains a specific amount of at least one element selected from the group consisting of As, Te, Sn, Sb, Bi, and Se, it is considered that the formation of the joint portion is further suppressed. The tendency of Cu 9 Al 4 intermetallic compounds. It is estimated that when a certain amount of these elements are contained, the interfacial tension between the Cu of the core material and the Pd of the coating layer is lowered when the ball is formed, and the wettability of the interface is improved, so that the Pd concentration at the ball joint interface is more prominently exhibited. . Therefore, the mutual diffusion suppression effect of Cu and Al by the Pd-concentrated layer is further enhanced, and as a result, the amount of Cu 9 Al 4 which is easily corroded by the action of Cl is less, and the joint reliability in the high-humidity environment of the ball joint portion is low. Significantly improved.
於具有Cu合金芯材與形成於Cu合金芯材之表面上之Pd被覆層、進而視需要於其表面上具有包含Au與Pd之表皮合金層的本發明中,若如後所述般進行擴散熱處理或退火熱處理,則芯材之Cu可藉由晶界擴散等而於被覆層或表皮合金層中擴散,使Cu到達至導線最表面而使Cu存在於最表面。因此,本發明中有於接合導線之最表面存在Cu之情況。 In the present invention having a Cu alloy core material and a Pd coating layer formed on the surface of the Cu alloy core material, and optionally a skin alloy layer containing Au and Pd on the surface thereof, diffusion is performed as will be described later. In the heat treatment or the annealing heat treatment, Cu of the core material can be diffused in the coating layer or the skin alloy layer by grain boundary diffusion or the like, so that Cu reaches the outermost surface of the wire and Cu exists on the outermost surface. Therefore, in the present invention, there is a case where Cu is present on the outermost surface of the bonding wire.
於如本發明般Pd被覆Cu接合導線含有特定量之As、Te、Sn、Sb、Bi、Se之情形時,若進而於接合導線之最表面存在Cu,則存在進一步抑制接合部中生成Cu9Al4金屬間化合物之傾向。推測於Pd被覆Cu接合導線含有特定量之As、Te、Sn、Sb、Bi、Se之情形時,若進而於接合導線之最表面存在Cu,則藉由接合導線所含之As、Te、Sn、Sb、Bi、Se與Cu之相互作用,於FAB形成時FAB表面之Pd濃化受到促進,球接合界面之Pd濃化更顯著地顯現。藉此,利用Pd濃化層之Cu與Al之相互擴散抑制效果進一步增強,容易因Cl之作用而腐蝕之Cu9Al4之生成量變少,球接合部之高溫高濕環境下之接合可靠性進一步提高。 When the Pd-coated Cu-bonding wire contains a specific amount of As, Te, Sn, Sb, Bi, or Se as in the present invention, if Cu is further present on the outermost surface of the bonding wire, the formation of Cu 9 in the joint portion is further suppressed. The tendency of Al 4 intermetallic compounds. It is presumed that when the Pd-coated Cu bonding wire contains a specific amount of As, Te, Sn, Sb, Bi, or Se, if Cu is further present on the outermost surface of the bonding wire, the As, Te, and Sn included in the bonding wire are included. The interaction of Sb, Bi, Se and Cu promotes the Pd concentration on the surface of the FAB during FAB formation, and the Pd concentration at the ball joint interface is more prominent. Thereby, the interdiffusion suppression effect of Cu and Al by the Pd-concentrated layer is further enhanced, the amount of Cu 9 Al 4 which is easily corroded by the action of Cl is less, and the joint reliability in the high-humidity environment of the ball joint portion is obtained. Further improve.
於藉由歐傑電子分光裝置對接合導線之表面進行測定時,若於表面檢測到Cu,則可謂於最表面存在Cu,可發揮上述效果。進而, 若相對於構成接合導線最表面之金屬元素的Cu濃度成為1原子%以上,則上述高溫高濕環境下之球接合部之接合可靠性之提高效果確實顯現,因而較佳。就進一步提高高溫高濕環境下之球接合部之接合可靠性之觀點而言,相對於構成接合導線最表面之金屬元素的Cu濃度更佳為1.5原子%以上,進而較佳為2原子%以上、2.5原子%以上、或3原子%以上。又,就抑制導線表面之耐氧化性或耐硫化性之降低、抑制接合導線之使用壽命縮短之觀點而言,相對於構成接合導線最表面之金屬元素的Cu濃度較佳為50原子%以下,更佳為45原子%以下,進而較佳為40原子%以下、35原子%以下、或30原子%以下。 When the surface of the bonding wire is measured by the Oujie electronic spectroscopic device, if Cu is detected on the surface, Cu can be present on the outermost surface, and the above effects can be exhibited. and then, When the Cu concentration of the metal element constituting the outermost surface of the bonding wire is 1 atom% or more, the effect of improving the bonding reliability of the ball joint portion in the high-temperature and high-humidity environment is improved, which is preferable. From the viewpoint of further improving the bonding reliability of the ball joint portion in a high-temperature and high-humidity environment, the Cu concentration of the metal element constituting the outermost surface of the bonding wire is preferably 1.5 atom% or more, and more preferably 2 atom% or more. 2.5 atom% or more, or 3 atom% or more. Moreover, the Cu concentration of the metal element constituting the outermost surface of the bonding wire is preferably 50 atom% or less from the viewpoint of suppressing the decrease in the oxidation resistance or the sulfidation resistance of the surface of the wire and suppressing the shortening of the service life of the bonding wire. It is more preferably 45 atom% or less, further preferably 40 atom% or less, 35 atom% or less, or 30 atom% or less.
進而,由表面上存在Cu所得之上述效果於芯材之Cu之純度較低之情形(例如3N以下)時顯現,尤其於Cu之純度為2N以下之情形時存在更顯著地顯現之傾向。 Further, the above-described effect obtained by the presence of Cu on the surface is exhibited when the purity of Cu of the core material is low (for example, 3 N or less), and in particular, when the purity of Cu is 2 N or less, there is a tendency to exhibit more prominently.
藉由接合導線之最表面上存在Cu所得的球接合部之高溫高濕環境下之接合可靠性提高效果為含有特定量之As、Te、Sn、Sb、Bi、Se之本發明之接合導線所特有。若為不含該等元素之普通之Pd被覆Cu接合導線,則球接合部之高溫高濕環境下之接合可靠性無法獲得如本發明般之提高效果。不僅如此,而且對於不含該等元素之普通之Pd被覆Cu接合導線而言,於接合導線之最表面上存在Cu會導致導線表面之耐氧化性或耐硫化性下降,接合導線之使用壽命縮短。又,FAB之偏芯多發,球形狀易劣化。又,可見楔形接合性劣化傾向。 The bonding reliability improving effect in a high-temperature and high-humidity environment by bonding a ball joint portion obtained by Cu on the outermost surface of the bonding wire is a bonding wire of the present invention containing a specific amount of As, Te, Sn, Sb, Bi, Se. Unique. If the ordinary Pd is not covered with the Cu-bonded wires, the bonding reliability in the high-temperature and high-humidity environment of the ball joint portion cannot be improved as in the present invention. Moreover, for a conventional Pd-coated Cu-bonded wire that does not contain such elements, the presence of Cu on the outermost surface of the bonded wire causes a decrease in oxidation resistance or sulfidation resistance of the wire surface, and the service life of the bonded wire is shortened. . In addition, the FAB has multiple eccentricities, and the shape of the ball is easily deteriorated. Further, it is seen that the wedge bondability tends to deteriorate.
藉由接合導線之最表面上存在Cu所得之上述效果於在本發明之接合導線中Pd被覆層為最表面之情形、及包含Au與Pd之合金表皮層為最表面之情形時均同樣地顯現。 The above-described effect obtained by the presence of Cu on the outermost surface of the bonding wire is similar to the case where the Pd coating layer is the outermost surface in the bonding wire of the present invention, and the case where the alloy skin layer containing Au and Pd is the outermost surface. .
此處,所謂最表面係指於未實施濺鍍等之狀態下藉由歐傑電子分光裝置測定接合導線之表面所得之區域。 Here, the outermost surface refers to a region obtained by measuring the surface of the bonding wire by an oujie electronic spectroscopic device in a state where sputtering or the like is not performed.
另一方面,就獲得良好之FAB形狀、進而良好之球接合性之觀點 而言,導線中之上述元素之濃度合計為100質量ppm以下,較佳為95質量ppm以下、90質量ppm以下、85質量ppm以下、或80質量ppm以下。又,於Sn、Sb濃度超過10質量ppm之情形,或Bi濃度超過1質量ppm之情形時,FAB形狀變得不良,因此藉由設為Sn≦10質量ppm、Sb≦10質量ppm、Bi≦1質量ppm,可進一步改善FAB形狀,因而較佳。進而,藉由將Se濃度設為4.9質量ppm以下,可進一步改善FAB形狀、楔形接合性,因而更佳。 On the other hand, the viewpoint of obtaining a good FAB shape and thus good ball jointability The concentration of the above elements in the wire is 100 ppm by mass or less, preferably 95 ppm by mass or less, 90 ppm by mass or less, 85 ppm by mass or less, or 80 ppm by mass or less. In addition, when the concentration of Sn and Sb exceeds 10 ppm by mass or the concentration of Bi exceeds 1 ppm by mass, the FAB shape becomes poor. Therefore, it is set to Sn ≦ 10 ppm by mass, Sb ≦ 10 ppm by mass, and Bi ≦ 1 ppm by mass can further improve the shape of the FAB, and thus is preferable. Further, by setting the Se concentration to 4.9 ppm by mass or less, the FAB shape and the wedge bondability can be further improved, which is more preferable.
於使接合導線中含有As、Te、Sn、Sb、Bi、Se時,採用使該等元素含有於Cu芯材中之方法、被覆於Cu芯材或導線表面而含有之方法均可發揮上述本發明之效果。該等成分之添加量為極微量,因此添加方法多變,無論以何種方法進行添加,只要包含指定濃度範圍之成分,則效果顯現。 When As, Te, Sn, Sb, Bi, and Se are contained in the bonding wire, the above-described method can be utilized by a method in which the elements are contained in the Cu core material, and a method of coating the surface of the Cu core material or the wire. The effect of the invention. Since the addition amount of these components is a very small amount, the addition method is variable, and the effect is apparent as long as the component of the specified concentration range is contained, regardless of the method of addition.
本發明之接合導線中,關於Pd被覆層之厚度,就進一步改善車載裝置所要求之高溫高濕環境下之球接合部之接合可靠性之觀點而言,較佳為0.015μm以上,更佳為0.02μm以上,進而較佳為0.025μm以上、0.03μm以上、0.035μm以上、0.04μm以上、0.045μm以上、或0.05μm以上。另一方面,就獲得良好之FAB形狀之觀點而言,Pd被覆層之厚度較佳為0.150μm以下,更佳為0.140μm以下、0.130μm以下、0.120μm以下、0.110μm以下、或0.100μm以下。 In the bonding wire of the present invention, the thickness of the Pd coating layer is preferably 0.015 μm or more from the viewpoint of further improving the bonding reliability of the ball joint portion in the high-temperature and high-humidity environment required for the in-vehicle device, and more preferably 0.02 μm or more, more preferably 0.025 μm or more, 0.03 μm or more, 0.035 μm or more, 0.04 μm or more, 0.045 μm or more, or 0.05 μm or more. On the other hand, the thickness of the Pd coating layer is preferably 0.150 μm or less, more preferably 0.140 μm or less, 0.130 μm or less, 0.120 μm or less, 0.110 μm or less, or 0.100 μm or less from the viewpoint of obtaining a good FAB shape. .
對上述接合導線之Cu合金芯材、Pd被覆層之定義進行說明。Cu合金芯材與Pd被覆層之邊界係以Pd濃度為基準加以判定。以Pd濃度為50原子%之位置作為邊界,將Pd濃度為50原子%以上之區域判定為Pd被覆層,將Pd濃度未達50原子%之區域判定為Cu合金芯材。其根據在於:若Pd被覆層中Pd濃度為50原子%以上,則可由Pd被覆層之構造獲得特性之改善效果。Pd被覆層亦可包含Pd單層之區域、Pd與Cu於導線之深度方向上具有濃度梯度之區域。於Pd被覆層中形成有該具有 濃度梯度之區域之原因在於:存在因製造步驟中之熱處理等而Pd與Cu之原子擴散之情況。本發明中,所謂濃度梯度,係指深度方向上之濃度變化程度係每0.1μm為10mol%以上。進而,Pd被覆層亦可包含不可避免之雜質。 The definition of the Cu alloy core material and the Pd coating layer of the above-mentioned bonding wire will be described. The boundary between the Cu alloy core material and the Pd coating layer is determined based on the Pd concentration. A region having a Pd concentration of 50 atom% was used as a boundary, and a region having a Pd concentration of 50 atom% or more was determined as a Pd coating layer, and a region having a Pd concentration of less than 50 atom% was determined as a Cu alloy core material. The reason for this is that if the Pd concentration in the Pd coating layer is 50 atom% or more, the effect of improving the properties can be obtained by the structure of the Pd coating layer. The Pd coating layer may also include a region of the Pd single layer, and a region where Pd and Cu have a concentration gradient in the depth direction of the wire. Formed in the Pd coating layer The reason for the region of the concentration gradient is that there is a case where atoms of Pd and Cu diffuse due to heat treatment or the like in the manufacturing step. In the present invention, the concentration gradient means that the degree of concentration change in the depth direction is 10 mol% or more per 0.1 μm. Further, the Pd coating layer may contain unavoidable impurities.
本發明之接合導線亦可於Pd被覆層之表面上進而具有包含Au與Pd之合金表皮層。藉此,本發明之接合導線可進一步提高接合可靠性,並且可改善楔形接合性。 The bonding wire of the present invention may further have an alloy skin layer containing Au and Pd on the surface of the Pd coating layer. Thereby, the bonding wire of the present invention can further improve the joint reliability and can improve the wedge bondability.
對上述接合導線之包含Au與Pd之合金表皮層之定義進行說明。包含Au與Pd之合金表皮層和Pd被覆層之邊界係以Au濃度為基準加以判定。以Au濃度為10原子%之位置作為邊界,將Au濃度為10原子%以上之區域判定為包含Au與Pd之合金表皮層,將未達10原子%之區域判定為Pd被覆層。又,即便是Pd濃度為50原子%以上之區域,若存在10原子%以上之Au,則判定為包含Au與Pd之合金表皮層。該等之根據在於:若Au濃度為上述濃度範圍,則可由Au表皮層之構造而期待特性之改善效果。包含Au與Pd之合金表皮層係Au-Pd合金,包括包含Au與Pd於導線之深度方向上具有濃度梯度之區域、及不含該具有濃度梯度之區域兩種情況。包含Au與Pd之合金表皮層較佳為包含該具有濃度梯度之區域。於包含Au與Pd之合金表皮層中形成有該具有濃度梯度之區域之原因在於:因製造步驟中之熱處理等而Au與Pd之原子擴散。進而,包含Au與Pd之合金表皮層亦可包含不可避免之雜質與Cu。 The definition of the alloy skin layer containing Au and Pd of the above bonding wire will be described. The boundary between the alloy skin layer containing the Au and Pd and the Pd coating layer was determined based on the Au concentration. A region having an Au concentration of 10 at% was used as a boundary, and a region having an Au concentration of 10 at% or more was determined to be an alloy skin layer containing Au and Pd, and a region having less than 10 at% was determined as a Pd coating layer. In addition, even in the region where the Pd concentration is 50 atom% or more, if there is 10 atom% or more of Au, it is determined that the alloy skin layer of Au and Pd is contained. The basis for this is that if the Au concentration is within the above concentration range, the effect of improving the properties can be expected from the structure of the Au skin layer. The alloy skin layer Au-Pd alloy containing Au and Pd includes both a region containing Au and Pd having a concentration gradient in the depth direction of the wire, and a region not containing the concentration gradient. The alloy skin layer comprising Au and Pd preferably comprises the region having the concentration gradient. The reason why the region having the concentration gradient is formed in the alloy skin layer containing Au and Pd is that atoms of Au and Pd are diffused by heat treatment or the like in the production step. Further, the alloy skin layer containing Au and Pd may contain unavoidable impurities and Cu.
本發明之接合導線中,包含Au與Pd之合金表皮層可與Pd被覆層反應,提高包含Au與Pd之合金表皮層、Pd被覆層、Cu合金芯材間之密接強度,抑制楔形接合時之Pd被覆層或包含Au與Pd之合金表皮層的剝離。藉此,本發明之接合導線可改善楔形接合性。就獲得良好之楔形接合性之觀點而言,包含Au與Pd之合金表皮層之厚度較佳為 0.0005μm以上,更佳為0.001μm以上、0.002μm以上、或0.003μm以上。就抑制偏芯、獲得良好之FAB形狀之觀點而言,包含Au與Pd之合金表皮層之厚度較佳為0.050μm以下,更佳為0.045μm以下、0.040μm以下、0.035μm以下、或0.030μm以下。再者,包含Au與Pd之合金表皮層可藉由與Pd被覆層相同之方法而形成。 In the bonding wire of the present invention, the alloy skin layer containing Au and Pd can react with the Pd coating layer to improve the adhesion strength between the alloy skin layer including the Au and Pd, the Pd coating layer, and the Cu alloy core material, and suppress the wedge bonding. Peeling of the Pd coating layer or the alloy skin layer containing Au and Pd. Thereby, the bonding wire of the present invention can improve the wedge bondability. The thickness of the alloy skin layer comprising Au and Pd is preferably from the viewpoint of obtaining good wedge bondability. 0.0005 μm or more, more preferably 0.001 μm or more, 0.002 μm or more, or 0.003 μm or more. The thickness of the alloy skin layer containing Au and Pd is preferably 0.050 μm or less, more preferably 0.045 μm or less, 0.040 μm or less, 0.035 μm or less, or 0.030 μm from the viewpoint of suppressing the eccentricity and obtaining a good FAB shape. the following. Further, the alloy skin layer containing Au and Pd can be formed by the same method as the Pd coating layer.
作為半導體裝置之封裝材料之模塑樹脂(環氧樹脂)中包含矽烷偶合劑。矽烷偶合劑具有提高有機物(樹脂)與無機物(矽或金屬)之密接性之作用,因此可提高與矽基板或金屬之密接性。進而,於要求更高溫下之可靠性之面向汽車之半導體等要求高密接性之情形時,添加「含硫矽烷偶合劑」。模塑樹脂所含之硫於HAST中之溫度條件即130℃左右之條件下不游離,但若於175℃以上(例如175℃~200℃)之條件下使用則游離。並且,若於175℃以上之高溫下游離之硫與Cu接觸,則加劇Cu之腐蝕,生成硫化物(Cu2S)或氧化物(CuO)。若於使用Cu接合導線之半導體裝置中發生Cu之腐蝕,則尤其球接合部之接合可靠性下降。 A molding resin (epoxy resin) as a sealing material for a semiconductor device contains a decane coupling agent. The decane coupling agent has an effect of improving the adhesion between the organic substance (resin) and the inorganic substance (cerium or metal), so that the adhesion to the ruthenium substrate or the metal can be improved. Further, in the case where high-adhesiveness is required for a semiconductor-oriented semiconductor or the like which requires reliability at a higher temperature, a "sulfur-containing decane coupling agent" is added. The sulfur contained in the molding resin is not released under the temperature condition of HAST, that is, at about 130 ° C, but is used if it is used at 175 ° C or higher (for example, 175 ° C to 200 ° C). Further, if the free sulfur is brought into contact with Cu at a high temperature of 175 ° C or higher, the corrosion of Cu is aggravated to form a sulfide (Cu 2 S) or an oxide (CuO). When Cu corrosion occurs in a semiconductor device using a Cu bonding wire, the bonding reliability of the ball bonding portion is particularly lowered.
作為對170℃以上之高溫環境下之球接合部可靠性進行評價之方法,採用HTS(High Temperature Storage Test)(高溫放置試驗)。對於暴露於高溫環境下之評價用樣品,測定球接合部之電阻值之經時變化,或測定球接合部之剪切強度之經時變化,藉此評價球接合部之接合壽命。近年來,對於汽車用半導體裝置,要求於175℃~200℃之HTS中之球接合部之可靠性提高。 As a method of evaluating the reliability of the ball joint portion in a high temperature environment of 170 ° C or higher, an HTS (High Temperature Storage Test) was employed. The evaluation sample was exposed to a high temperature environment, and the change in the resistance value of the ball joint portion was measured, or the change in shear strength of the ball joint portion was measured over time to evaluate the joint life of the ball joint portion. In recent years, for automotive semiconductor devices, the reliability of ball joints in HTS at 175 ° C to 200 ° C is required to be improved.
本發明之接合導線較佳為進而包含選自Ni、Zn、Rh、In、Ir、Pt、Ga、Ge中之至少1種以上之元素,上述元素相對於導線整體之濃度分別為0.011~1.2質量%。藉由本發明之接合導線進而含有該等元素,球接合部之高溫環境下之接合可靠性中,175℃以上之HTS中之成績改善。就改善球接合部之高溫環境下之接合可靠性(尤其是175℃ 以上之HTS中之成績)之觀點而言,上述元素相對於導線整體之濃度分別較佳為0.011質量%以上,更佳為0.020質量%以上,進而較佳為0.030質量%以上、0.050質量%以上、0.070質量%以上、0.090質量%以上、0.10質量%以上、0.15質量%以上、或0.20質量%以上。就獲得良好之FAB形狀之觀點、抑制接合導線之硬質化而抑制楔形接合性之降低之觀點而言,上述元素相對於導線整體之濃度分別較佳為1.2質量%以下,更佳為1.1質量%以下。於本發明之接合導線包含選自Ni、Zn、Rh、In、Ir、Pt、Ga、Ge中之複數種元素之情形時,該等元素相對於導線整體之濃度合計較佳為0.011~2.2質量%。就改善球接合部之高溫環境下之接合可靠性(尤其是175℃以上之HTS中之成績)之觀點而言,上述元素相對於導線整體之濃度合計較佳為0.011質量%以上,更佳為0.020質量%以上,進而較佳為0.030質量%以上、0.050質量%以上、0.070質量%以上、0.090質量%以上、0.10質量%以上、0.15質量%以上、或0.20質量%以上。就獲得良好之FAB形狀之觀點、抑制接合導線之硬質化而抑制楔形接合性之降低之觀點而言,上述元素相對於導線整體之濃度合計較佳為2.0質量%以下、1.8質量%以下、或1.6質量%以下。 The bonding wire of the present invention preferably further comprises at least one element selected from the group consisting of Ni, Zn, Rh, In, Ir, Pt, Ga, and Ge, and the concentration of the element relative to the entire wire is 0.011 to 1.2 mass, respectively. %. According to the bonding wire of the present invention and the element, the bonding reliability in a high-temperature environment of the ball joint portion is improved in the HTS at 175 ° C or higher. Improves joint reliability in high temperature environments where ball joints are high (especially 175 ° C) The concentration of the above element with respect to the entire wire is preferably 0.011% by mass or more, more preferably 0.020% by mass or more, and further preferably 0.030% by mass or more and 0.050% by mass or more, from the viewpoint of the above-mentioned results in the HTS. 0.070% by mass or more, 0.090% by mass or more, 0.10% by mass or more, 0.15% by mass or more, or 0.20% by mass or more. The concentration of the element relative to the entire wire is preferably 1.2% by mass or less, and more preferably 1.1% by mass, from the viewpoint of obtaining a good FAB shape and suppressing the hardening of the bonding wire to suppress the decrease in the wedge bondability. the following. In the case where the bonding wire of the present invention comprises a plurality of elements selected from the group consisting of Ni, Zn, Rh, In, Ir, Pt, Ga, and Ge, the total concentration of the elements relative to the entire wire is preferably 0.011 to 2.2. %. The total concentration of the above elements with respect to the entire wire is preferably 0.011% by mass or more, more preferably from the viewpoint of improving the bonding reliability in a high-temperature environment of the ball joint portion (especially in the HTS at 175 ° C or higher). 0.020% by mass or more, more preferably 0.030% by mass or more, 0.050% by mass or more, 0.070% by mass or more, 0.090% by mass or more, 0.10% by mass or more, 0.15% by mass or more, or 0.20% by mass or more. From the viewpoint of obtaining a good FAB shape and suppressing the hardening of the bonding wire and suppressing the decrease in the wedge bondability, the total concentration of the element with respect to the entire wire is preferably 2.0% by mass or less and 1.8% by mass or less, or 1.6% by mass or less.
又,本發明之接合導線中,若Cu合金芯材包含Pd且Cu合金芯材所含之Pd之濃度為0.05~1.2質量%則較佳。藉此,可獲得與上述包含Ni、Zn、Rh、In、Ir、Pt、Ga、Ge之情形相同之效果。本發明之接合導線中,關於Cu合金芯材所含之Pd之濃度,就改善球接合部之高溫環境下之接合可靠性(尤其是175℃以上之HTS中之成績)之觀點而言,較佳為0.05質量%以上,更佳為0.1質量%以上、0.2質量%以上、0.3質量%以上、0.4質量%以上、或0.5質量%以上。又,就獲得良好之FAB形狀之觀點、抑制接合導線之硬質化而抑制楔形接合性之降低之觀點而言,Cu合金芯材所含之Pd之濃度較佳為1.2質量%以下,更佳為1.1 質量%以下。本發明之接合導線藉由以上述含量範圍含有Ni、Zn、Rh、In、Ir、Pt、Ga、Ge、Pd,可提高迴路形成性,即,可減少於高密度安裝中成問題之偏斜。其原因在於:藉由接合導線包含該等元素,接合導線之降伏強度提高,可抑制接合導線之變形。再者,作為由接合導線製品求出Cu合金芯材所含之Pd之濃度的方法,例如可列舉:使接合導線之剖面露出,對Cu合金芯材之區域進行濃度分析之方法;一面利用濺擊等自接合導線之表面朝向深度方向切削,一面對Cu合金芯材之區域進行濃度分析之方法。例如於Cu合金芯材包含具有Pd之濃度梯度之區域之情形時,只要對接合導線之剖面進行線分析,對不具有Pd之濃度梯度之區域(即,深度方向上之Pd之濃度變化程度係每0.1μm未達10mol%之區域)進行濃度分析即可。濃度分析之方法將於下文中說明。 Further, in the bonding wire of the present invention, it is preferable that the Cu alloy core material contains Pd and the concentration of Pd contained in the Cu alloy core material is 0.05 to 1.2% by mass. Thereby, the same effects as those in the case of containing Ni, Zn, Rh, In, Ir, Pt, Ga, and Ge described above can be obtained. In the bonding wire of the present invention, the concentration of Pd contained in the Cu alloy core material is improved in terms of improving the bonding reliability in a high-temperature environment of the ball joint portion (especially in the HTS at 175 ° C or higher). It is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, 0.2% by mass or more, 0.3% by mass or more, 0.4% by mass or more, or 0.5% by mass or more. In addition, the concentration of Pd contained in the Cu alloy core material is preferably 1.2% by mass or less, more preferably from the viewpoint of obtaining a good FAB shape, suppressing the hardening of the bonding wire, and suppressing the decrease in the wedge bondability. 1.1 Below mass%. The bonding wire of the present invention can improve the loop formation property by containing Ni, Zn, Rh, In, Ir, Pt, Ga, Ge, Pd in the above content range, that is, it can reduce the skewness which is problematic in high-density mounting. . The reason for this is that by including these elements in the bonding wires, the drop strength of the bonding wires is improved, and deformation of the bonding wires can be suppressed. In addition, as a method of determining the concentration of Pd contained in the Cu alloy core material by joining the lead wire products, for example, a method of exposing the cross section of the bonding wire and performing concentration analysis on the region of the Cu alloy core material; The surface of the self-bonding wire is cut toward the depth direction, and a method of concentration analysis is performed on the area of the Cu alloy core material. For example, in the case where the Cu alloy core material contains a region having a concentration gradient of Pd, as long as the profile of the bonding wire is subjected to line analysis, the region having a concentration gradient without Pd (that is, the degree of change in the concentration of Pd in the depth direction is The concentration analysis may be performed every 0.1 μm in a region of less than 10 mol%. The method of concentration analysis will be described below.
又,藉由以上述含量範圍含有Ni、Zn、Rh、In、Ir、Pt、Ga、Ge、Pd,本發明之接合導線可進一步延長溫度130℃、相對濕度85%之高溫高濕環境下之球接合部之接合壽命。可認為若本發明之接合導線進而含有特定量之Ni、Zn、Rh、In、Ir、Pt、Ga、Ge、Pd,則存在進一步抑制接合部中生成Cu9Al4金屬間化合物之傾向。推測若進而含有該等元素,則芯材之Cu與被覆層之Pd的界面張力進一步降低,球接合界面之Pd濃化更顯著地顯現。因此,由Pd濃化層所得之Cu與Al之相互擴散抑制效果進一步增強,結果可大幅度地減少容易因Cl之作用而腐蝕之Cu9Al4之生成量,球接合部之高溫高濕環境下之可靠性進一步提高。 Moreover, by containing Ni, Zn, Rh, In, Ir, Pt, Ga, Ge, Pd in the above content range, the bonding wire of the present invention can further extend the temperature in a high temperature and high humidity environment at a temperature of 130 ° C and a relative humidity of 85%. The joint life of the ball joint. When the bonding wire of the present invention further contains a specific amount of Ni, Zn, Rh, In, Ir, Pt, Ga, Ge, or Pd, it is considered that the Cu 9 Al 4 intermetallic compound is further suppressed from being formed in the joint portion. It is presumed that if these elements are further contained, the interfacial tension between the Cu of the core material and the Pd of the coating layer is further lowered, and the Pd concentration at the ball joint interface is more prominent. Therefore, the mutual diffusion suppressing effect of Cu and Al obtained from the Pd-concentrated layer is further enhanced, and as a result, the amount of Cu 9 Al 4 which is easily corroded by the action of Cl can be greatly reduced, and the high-humidity environment of the ball joint portion is high-temperature and high-humidity. The reliability is further improved.
本發明之接合導線較佳為進而包含選自B、P、Mg、Ca、La中之至少1種以上之元素,且上述元素相對於導線整體之濃度分別為1~100質量ppm。藉此,可改善於高密度安裝時所要求之球接合部之壓塌形狀,即,可改善球接合部形狀之正圓性。可認為其原因在於:藉 由添加上述元素,可使球之結晶粒徑微細化,可抑制球之變形。就改善球接合部之壓塌形狀、即改善球接合部形狀之正圓性之觀點而言,上述元素相對於導線整體之濃度分別較佳為1質量ppm以上,更佳為2質量ppm以上、3質量ppm以上、4質量ppm以上、或5質量ppm以上。就抑制球之硬質化而抑制球接合時之晶片損傷之觀點而言,上述元素相對於導線整體之濃度分別較佳為100質量ppm以下,更佳為95質量ppm以下、90質量ppm以下、85質量ppm以下、或80質量ppm以下。於本發明之接合導線包含選自B、P、Mg、Ca、La中之複數種元素之情形時,該等元素相對於導線整體之濃度合計較佳為1~100質量ppm。就改善球接合部之壓塌形狀、即改善球接合部形狀之正圓性之觀點而言,上述元素相對於導線整體之濃度合計較佳為1質量ppm以上,更佳為2質量ppm以上、3質量ppm以上、4質量ppm以上、或5質量ppm以上。又,就抑制球之硬質化而抑制球接合時之晶片損傷之觀點而言,上述元素相對於導線整體之濃度合計較佳為90質量ppm以下、80質量ppm以下、或70質量ppm以下。 The bonding wire of the present invention preferably further contains at least one element selected from the group consisting of B, P, Mg, Ca, and La, and the concentration of the element relative to the entire wire is 1 to 100 ppm by mass. Thereby, the collapsed shape of the ball joint portion required for high-density mounting can be improved, that is, the roundness of the shape of the ball joint portion can be improved. It can be considered as the reason: By adding the above elements, the crystal grain size of the ball can be made fine, and the deformation of the ball can be suppressed. The concentration of the element relative to the entire wire is preferably 1 ppm by mass or more, and more preferably 2 ppm by mass or more, from the viewpoint of improving the collapsed shape of the ball joint portion, that is, improving the roundness of the shape of the ball joint portion. 3 mass ppm or more, 4 mass ppm or more, or 5 mass ppm or more. The concentration of the above element with respect to the entire wire is preferably 100 ppm by mass or less, more preferably 95 ppm by mass or less, 90 ppm by mass or less, or 85, from the viewpoint of suppressing the hardening of the ball and suppressing wafer damage during ball bonding. The mass is ppm or less, or 80 ppm by mass or less. In the case where the bonding wire of the present invention contains a plurality of elements selected from the group consisting of B, P, Mg, Ca, and La, the total concentration of the elements relative to the entire wire is preferably from 1 to 100 ppm by mass. In view of improving the collapsed shape of the ball joint portion, that is, the roundness of the shape of the ball joint portion, the total concentration of the element with respect to the entire wire is preferably 1 ppm by mass or more, more preferably 2 ppm by mass or more. 3 mass ppm or more, 4 mass ppm or more, or 5 mass ppm or more. In addition, from the viewpoint of suppressing the hardening of the ball and suppressing wafer damage during ball bonding, the total concentration of the element with respect to the entire wire is preferably 90 ppm by mass or less, 80 ppm by mass or less, or 70 ppm by mass or less.
關於Pd被覆層、包含Au與Pd之合金表皮層之濃度分析、Cu合金芯材中之Pd之濃度分析,有效的是一面利用濺擊等自接合導線之表面朝向深度方向切削一面進行分析之方法,或者使導線剖面露出而進行線分析、點分析等之方法。用於該等濃度分析之分析裝置可利用掃描式電子顯微鏡或穿透式電子顯微鏡所附帶之歐傑電子分光分析裝置、能量分散型X射線分析裝置、電子束微量分析器等。作為使導線剖面露出之方法,可利用機械研磨、離子蝕刻法等。關於接合導線中之As、Te、Sn、Sb、Bi、Se、Ni、Zn、Rh、In、Ir、Pt、Ga、Ge、B、P、Mg、Ca、La等之微量分析,可利用ICP(Inductively Coupled Plasma,感應耦合電漿)發射分光分析裝置或ICP質量分析裝置對使接合導線於強酸中溶解所得之溶液進行分析,以接合導線整體所含之元 素之濃度之形式進行檢測。 The concentration analysis of the Pd coating layer, the alloy skin layer containing Au and Pd, and the concentration analysis of Pd in the Cu alloy core material are effective in that the surface of the Pd coating layer is cut from the surface of the bonding wire to the depth direction by sputtering or the like. Or a method of exposing the cross section of the wire to perform line analysis, point analysis, or the like. The analysis device used for the concentration analysis may be an Oujie electronic spectroscopic analyzer, an energy dispersive X-ray analyzer, an electron beam microanalyzer, or the like attached to a scanning electron microscope or a transmission electron microscope. As a method of exposing the cross section of the wire, mechanical polishing, ion etching, or the like can be used. For the micro analysis of As, Te, Sn, Sb, Bi, Se, Ni, Zn, Rh, In, Ir, Pt, Ga, Ge, B, P, Mg, Ca, La, etc. in the bonding wire, ICP can be used. (Inductively Coupled Plasma) emission spectroscopic analyzer or ICP mass spectrometer analyzes a solution obtained by dissolving a bonding wire in a strong acid to bond the elements contained in the entire wire The form of the concentration of the substance is detected.
本發明之一較佳實施形態中,於測定接合導線表面之結晶方位時之測定結果中,相對於接合導線長度方向而角度差為15度以下之結晶方位<111>之存在比率以面積率計為30~100%。該實施形態中,可提高迴路形成性,即,可提高於高密度安裝時所要求之迴路之直線性,並且可減小迴路高度之偏差。其原因在於:若表面結晶方位一致,則對橫向變形之耐受性增強,抑制橫向變形,故可抑制偏斜不良。就抑制偏斜不良之觀點而言,上述結晶方位<111>之存在比率以面積率計更佳為35%以上,進而較佳為40%以上、45%以上、50%以上、或55%以上。 In a preferred embodiment of the present invention, in the measurement result of measuring the crystal orientation of the surface of the bonding wire, the ratio of the crystal orientation <111> having an angular difference of 15 degrees or less with respect to the longitudinal direction of the bonding wire is measured by the area ratio. It is 30~100%. In this embodiment, the circuit formation property can be improved, that is, the linearity of the circuit required for high-density mounting can be improved, and the variation in the circuit height can be reduced. The reason for this is that if the crystal orientations of the surfaces are uniform, the resistance to the lateral deformation is enhanced, and the lateral deformation is suppressed, so that the skewness can be suppressed. The ratio of the crystal orientation <111> is more preferably 35% or more, more preferably 40% or more, 45% or more, 50% or more, or 55% or more, from the viewpoint of suppressing the skewness. .
(製造方法) (Production method)
其次,對本發明之實施形態之接合導線之製造方法進行說明。接合導線係藉由如下方式獲得,即,製造用於芯材之Cu合金後,細細地加工成導線狀,形成Pd被覆層、Au層,進行熱處理。亦存在於形成Pd被覆層、Au層後再次進行拉絲與熱處理之情況。對Cu合金芯材之製造方法、Pd被覆層、包含Au與Pd之合金表皮層之形成方法、熱處理方法進行詳細說明。 Next, a method of manufacturing a bonded wire according to an embodiment of the present invention will be described. The bonding wire is obtained by, after manufacturing a Cu alloy for a core material, finely processing into a wire shape, forming a Pd coating layer, an Au layer, and performing heat treatment. There is also a case where the Pd coating layer and the Au layer are formed and then the drawing and heat treatment are performed again. A method for producing a Cu alloy core material, a Pd coating layer, a method for forming an alloy skin layer containing Au and Pd, and a heat treatment method will be described in detail.
用於芯材之Cu合金係藉由將成為原料之Cu與添加元素一起熔解、凝固而獲得。熔解時可利用電弧加熱爐、高頻加熱爐、電阻加熱爐等。為了防止來自大氣中之O2、H2等氣體混入,較佳為於真空環境或者Ar或N2等惰性氣體環境中進行熔解。 The Cu alloy used for the core material is obtained by melting and solidifying Cu as a raw material together with an additive element. An arc furnace, a high frequency heating furnace, a resistance heating furnace, or the like can be used for melting. In order to prevent the incorporation of gases such as O 2 and H 2 from the atmosphere, it is preferred to carry out the melting in a vacuum atmosphere or an inert gas atmosphere such as Ar or N 2 .
於Cu合金芯材之表面上形成Pd被覆層、Au層之方法存在鍍敷法、蒸鍍法、熔融法等。鍍敷法可應用電解鍍敷法、無電解鍍敷法之任一種。對於被稱為觸擊鍍敷、閃熔鍍敷之電解鍍敷而言,鍍敷速度較快,與基底之密接性亦良好。用於無電解鍍敷之溶液分為置換型與還原型,於厚度較薄之情形時,僅進行置換型鍍敷便足矣,於厚度較 厚之情形時,有效的是分階段於置換型鍍敷後實施還原型鍍敷。 A method of forming a Pd coating layer or an Au layer on the surface of a Cu alloy core material includes a plating method, a vapor deposition method, a melting method, and the like. The plating method may be any one of electrolytic plating and electroless plating. For electroplating, which is called strike plating or flash plating, the plating speed is fast and the adhesion to the substrate is good. The solution used for electroless plating is divided into a replacement type and a reduction type. When the thickness is thin, only the replacement type plating is sufficient, and the thickness is relatively large. In the case of a thick case, it is effective to perform reduction plating after the displacement plating in stages.
關於蒸鍍法,可利用濺鍍法、離子鍍覆法、真空蒸鍍等物理吸附及電漿CVD(Chemical Vapor Deposition,化學氣相沈積)等化學吸附。該等均為乾式,於Pd被覆層、Au層形成後無需洗淨而無洗淨時之表面污染等擔憂。 As the vapor deposition method, chemical adsorption such as physical adsorption such as sputtering, ion plating, or vacuum vapor deposition, or chemical vapor deposition (CVD) can be used. These are dry types, and there is no need to wash after the formation of the Pd coating layer or the Au layer, and there is no concern such as surface contamination during washing.
藉由在Pd被覆層、Au層形成後進行熱處理,Pd被覆層之Pd擴散至Au層中,形成包含Au與Pd之合金表皮層。亦可並非於形成Au層後藉由熱處理形成包含Au與Pd之合金表皮層,而自最初開始被覆包含Au與Pd之合金表皮層。 After the Pd coating layer and the Au layer are formed and heat-treated, Pd of the Pd coating layer is diffused into the Au layer to form an alloy skin layer containing Au and Pd. Alternatively, the alloy skin layer containing Au and Pd may be formed by heat treatment after forming the Au layer, and the alloy skin layer containing Au and Pd may be coated from the beginning.
對於Pd被覆層、包含Au與Pd之合金表皮層之形成而言,拉絲至最終線徑後形成該等層之方法、與於粗徑之Cu合金芯材上形成該等層後進行複數次拉絲直至達成目標線徑之方法均有效。於前者之以最終徑之狀態形成Pd被覆層、包含Au與Pd之合金表皮層之情形時,便於製造、品質管理等。於後者之將Pd被覆層、包含Au與Pd之合金表皮層與拉絲加以組合之情形時,於與Cu合金芯材之密接性提高之方面有利。作為各形成法之具體例,可列舉:一面於電解鍍敷溶液中連續地掠過導線,一面於最終線徑之Cu合金芯材上形成Pd被覆層、包含Au與Pd之合金表皮層之方法;或者將較粗之Cu合金芯材浸漬於電解或無電解之鍍敷浴中形成Pd被覆層、包含Au與Pd之合金表皮層後,將導線拉細至最終線徑之方法等。 For the formation of a Pd coating layer, an alloy skin layer containing Au and Pd, a method of forming the layers after drawing to a final wire diameter, and forming the layers on a Cu alloy core material having a large diameter, and then performing a plurality of drawing The method until the target diameter is achieved is valid. When the Pd coating layer and the alloy skin layer of Au and Pd are formed in the state of the final diameter in the former state, it is easy to manufacture, quality control, and the like. In the case where the Pd coating layer and the alloy skin layer containing Au and Pd are combined with the wire drawing, the adhesion to the Cu alloy core material is improved. Specific examples of the respective formation methods include a method of forming a Pd coating layer and an alloy skin layer containing Au and Pd on a Cu alloy core material having a final wire diameter while continuously traversing a wire in an electrolytic plating solution. Or a method in which a thick Cu alloy core material is immersed in an electrolytic or electroless plating bath to form a Pd coating layer, an alloy skin layer containing Au and Pd, and then the wire is drawn to a final wire diameter.
於形成Pd被覆層、包含Au與Pd之合金表皮層後,存在進行熱處理之情況。藉由進行熱處理,於包含Au與Pd之合金表皮層、Pd被覆層、Cu合金芯材之間原子擴散而密接強度提高,因此可抑制加工中之包含Au與Pd之合金表皮層或Pd被覆層的剝離,於生產性提高之方面有效。為了防止來自大氣中之O2混入,較佳為於真空環境或Ar或N2等惰性氣體環境中進行熱處理。 After the Pd coating layer and the alloy skin layer containing Au and Pd are formed, there is a case where heat treatment is performed. By heat treatment, atomic diffusion between the alloy skin layer including the Au and Pd, the Pd coating layer, and the Cu alloy core material improves the adhesion strength, so that the alloy skin layer or the Pd coating layer containing Au and Pd during processing can be suppressed. The stripping is effective in terms of productivity improvement. In order to prevent the incorporation of O 2 from the atmosphere, it is preferred to carry out heat treatment in a vacuum atmosphere or an inert gas atmosphere such as Ar or N 2 .
如上所述,藉由調整對接合導線實施之擴散熱處理或退火熱處理之條件,芯材之Cu可藉由晶界擴散等而於Pd被覆層或包含Au與Pd之表皮合金層中擴散,使Cu到達至接合導線之最表面而使Cu存在於最表面。作為用以使Cu存在於最表面上之熱處理,可採用如上所述般用以形成包含Au與Pd之合金表皮層之熱處理。於進行用以形成合金表皮層之熱處理時,藉由選擇熱處理溫度與時間,可使最表面存在Cu或不存在Cu。進而,亦可將最表面之Cu濃度調整為特定範圍(例如1~50原子%之範圍)。亦可藉由形成合金表皮層時以外進行之熱處理而使Cu擴散至最表面。 As described above, by adjusting the conditions of the diffusion heat treatment or the annealing heat treatment applied to the bonding wires, Cu of the core material can be diffused in the Pd coating layer or the skin alloy layer containing Au and Pd by grain boundary diffusion or the like to cause Cu It reaches the outermost surface of the bonding wire so that Cu exists on the outermost surface. As the heat treatment for causing Cu to exist on the outermost surface, a heat treatment for forming an alloy skin layer containing Au and Pd as described above can be employed. When the heat treatment for forming the alloy skin layer is performed, Cu may be present on the outermost surface or Cu may be absent by selecting the heat treatment temperature and time. Further, the Cu concentration on the outermost surface may be adjusted to a specific range (for example, in the range of 1 to 50 atom%). It is also possible to diffuse Cu to the outermost surface by heat treatment other than when forming the alloy skin layer.
如上所述,於使接合導線中含有As、Te、Sn、Sb、Bi、Se時,採用使該等元素含有於Cu芯材中之方法、被覆於Cu芯材或導線表面而含有之方法均可發揮上述本發明之效果。關於Ni、Zn、Rh、In、Ir、Pt、Ga、Ge、B、P、Mg、Ca、La亦同樣。 As described above, when As, Te, Sn, Sb, Bi, and Se are contained in the bonding wire, the method of including the elements in the Cu core material, and coating the surface of the Cu core material or the wire are used. The effects of the above invention can be exerted. The same applies to Ni, Zn, Rh, In, Ir, Pt, Ga, Ge, B, P, Mg, Ca, and La.
作為上述成分之添加方法,最簡便的是預先添加至Cu合金芯材之起始材料中之方法。例如秤量高純度之銅與上述成分元素原料作為起始原料後,將該等於高真空下或氮氣或氬氣等惰性氣體環境下加熱而熔解,藉此製作添加有目標濃度範圍之上述成分之鑄錠,作為包含目標濃度之上述成分元素之起始材料。因此,於一較佳實施形態中,本發明之接合導線之Cu合金芯材以下述元素相對於導線整體之濃度合計為0.1~100質量ppm、且Sn≦10質量ppm、Sb≦10質量ppm、Bi≦1質量ppm之方式包含選自As、Te、Sn、Sb、Bi、Se中之至少1種以上之元素。該合計濃度之較佳數值範圍如上所述。於另一較佳實施形態中,本發明之接合導線之Cu合金芯材以下述元素相對於導線整體之濃度分別為0.011~1.2質量%之方式包含選自Ni、Zn、Rh、In、Ir、Pt、Ga、Ge中之至少1種以上之元素。該濃度之較佳數值範圍如上所述。於一較佳實施形態中,Cu合金芯材之Cu之純度為3N以下(較佳 為2N以下)。關於先前之Pd被覆Cu接合導線,就接合性之觀點而言使用高純度(4N以上)之Cu芯材,存在避免使用低純度之Cu芯材之傾向。含有特定元素之本發明之接合導線特別適於如上所述般使用Cu純度較低之Cu合金芯材之情形,且實現了車載裝置所要求之高溫高濕環境下之球接合部之接合可靠性。於另一較佳實施形態中,本發明之接合導線之Cu合金芯材以下述元素相對於導線整體之濃度分別成為1~100質量ppm之方式包含選自B、P、Mg、Ca、La中之至少1種以上之元素。該濃度之較佳數值範圍如上所述。 As a method of adding the above components, the most convenient method is to add it to the starting material of the Cu alloy core material in advance. For example, after weighing high-purity copper and the above-mentioned component element raw materials as a starting material, the mixture is heated and melted under an atmosphere of high vacuum or nitrogen or argon gas to prepare a casting to which the above-mentioned components having a target concentration range are added. The ingot is used as a starting material for the above-mentioned constituent elements containing the target concentration. Therefore, in a preferred embodiment, the Cu alloy core material of the bonding wire of the present invention has a total concentration of the following elements with respect to the entire wire of 0.1 to 100 ppm by mass, and Sn ≦ 10 ppm by mass, Sb ≦ 10 ppm by mass, The Bi≦1 mass ppm includes at least one element selected from the group consisting of As, Te, Sn, Sb, Bi, and Se. The preferred range of values for the total concentration is as described above. In another preferred embodiment, the Cu alloy core material of the bonding wire of the present invention comprises a material selected from the group consisting of Ni, Zn, Rh, In, Ir, and the like, wherein the concentration of the element is 0.011 to 1.2% by mass, respectively. At least one or more of Pt, Ga, and Ge. The preferred range of values for this concentration is as described above. In a preferred embodiment, the Cu of the Cu alloy core material has a purity of 3 N or less (preferably It is 2N or less). Regarding the conventional Pd-coated Cu-bonded wire, a high-purity (4N or more) Cu core material is used from the viewpoint of bondability, and there is a tendency to avoid the use of a low-purity Cu core material. The bonding wire of the present invention containing a specific element is particularly suitable for the case of using a Cu alloy core material having a low Cu purity as described above, and achieving the joint reliability of the ball joint portion in a high temperature and high humidity environment required for an in-vehicle device. . In another preferred embodiment, the Cu alloy core material of the bonding wire of the present invention comprises a material selected from the group consisting of B, P, Mg, Ca, and La in such a manner that the concentration of the following elements is 1 to 100 ppm by mass with respect to the entire wire. At least one or more elements. The preferred range of values for this concentration is as described above.
亦可藉由在導線製造步驟之中途使上述成分被覆於導線表面而含有上述成分。於該情形時,可組入至導線製造步驟中之某處,亦可反覆多次。亦可組入至複數個步驟中。可於Pd被覆前之Cu表面上添加,亦可於Pd被覆後之Pd表面上添加,亦可於Au被覆後之Au表面上添加,可組入至各被覆步驟中。作為被覆方法,可自(1)水溶液之塗佈乾燥熱處理、(2)鍍敷法(濕式)、(3)蒸鍍法(乾式)中選擇。 The above components may be contained by coating the above components on the surface of the wire in the middle of the wire manufacturing step. In this case, it can be incorporated into somewhere in the wire manufacturing step, or it can be repeated multiple times. It can also be grouped into multiple steps. It may be added to the surface of the Cu before the Pd coating, or may be added to the surface of the Pd after the Pd coating, or may be added to the surface of the Au after the Au coating, and may be incorporated into each coating step. As a coating method, it can be applied from (1) aqueous solution dry It is selected from heat treatment, (2) plating method (wet type), and (3) vapor deposition method (dry type).
於採用水溶液之塗佈乾燥熱處理之方法之情形時,首先利用包含上述成分元素之水溶性化合物製備適當濃度之水溶液。藉此,可將上述成分取入至導線材料中。可組入至導線製造步驟中之某處,亦可反覆多次。亦可組入至複數個步驟中。可於Pd被覆前之Cu表面上添加,亦可於Pd被覆後之Pd表面上添加,亦可於Au被覆後之Au表面上添加,亦可組入至各被覆步驟中。 Coating with aqueous solution dry In the case of the heat treatment method, an aqueous solution of a suitable concentration is first prepared by using a water-soluble compound containing the above-mentioned constituent elements. Thereby, the above components can be taken into the wire material. It can be incorporated into somewhere in the wire manufacturing step, or it can be repeated multiple times. It can also be grouped into multiple steps. It may be added to the surface of the Cu before the Pd coating, or may be added to the surface of the Pd after the Pd coating, or may be added to the Au surface after the Au coating, or may be incorporated into each coating step.
於採用鍍敷法(濕式)之情形時,鍍敷法可應用電解鍍敷法、無電解鍍敷法之任一種。關於電解鍍敷法,除了通常之電解鍍敷以外,亦可應用被稱為閃熔鍍敷之鍍敷速度較速且與基底之密接性亦良好之鍍敷法。用於無電解鍍敷之溶液有置換型與還原型。一般而言,於鍍敷厚度較薄之情形時應用置換型鍍敷,於較厚之情形時應用還原型鍍敷,可應用任一種,只要根據所欲添加之濃度而選擇並調整鍍敷液濃 度、時間即可。電解鍍敷法、無電解鍍敷法均可組入至導線製造步驟中之某處,亦可反覆多次。亦可組入至複數個步驟中。可於Pd被覆前之Cu表面上添加,亦可於Pd被覆後之Pd表面上添加,亦可於Au被覆後之Au表面上添加,亦可組入至各被覆步驟中。 In the case of using a plating method (wet type), the plating method may be applied to any of electrolytic plating method and electroless plating method. Regarding the electrolytic plating method, in addition to the usual electrolytic plating, a plating method in which the plating speed called flash paste plating is fast and the adhesion to the substrate is also good can be applied. The solution for electroless plating has a substitution type and a reduction type. Generally, displacement plating is applied when the plating thickness is thin, and reduction plating is applied in a thicker case, and any one may be applied, and the plating solution may be selected and adjusted according to the concentration to be added. concentrated Degree, time can be. Electrolytic plating and electroless plating can be incorporated into somewhere in the wire manufacturing step, or multiple times. It can also be grouped into multiple steps. It may be added to the surface of the Cu before the Pd coating, or may be added to the surface of the Pd after the Pd coating, or may be added to the Au surface after the Au coating, or may be incorporated into each coating step.
蒸鍍法(乾式)中,有濺鍍法、離子鍍覆法、真空蒸鍍法、電漿CVD等。由於為乾式,故具有無需預處理後處理且亦無污染擔憂之優點。一般而言,蒸鍍法存在目標元素之添加速度較慢之問題,但由於上述成分元素之添加濃度相對較低,故而為適於實現本發明之目的之方法之一。 Among the vapor deposition methods (dry type), there are a sputtering method, an ion plating method, a vacuum evaporation method, a plasma CVD method, and the like. Since it is dry, it has the advantage of no post-treatment and no pollution concerns. In general, the vapor deposition method has a problem that the addition rate of the target element is slow, but since the concentration of the above-mentioned component elements is relatively low, it is one of the methods suitable for achieving the object of the present invention.
各蒸鍍法可組入至導線製造步驟中之某處,亦可反覆多次。亦可組入至複數個步驟中。可於Pd被覆前之Cu表面上添加,亦可於Pd被覆後之Pd表面上添加,亦可於Au被覆後之Au表面上添加,亦可組入至各被覆步驟中。 Each vapor deposition method can be incorporated into somewhere in the wire manufacturing step, or it can be repeated multiple times. It can also be grouped into multiple steps. It may be added to the surface of the Cu before the Pd coating, or may be added to the surface of the Pd after the Pd coating, or may be added to the Au surface after the Au coating, or may be incorporated into each coating step.
使測定接合導線表面之結晶方位時的相對於接合導線長度方向而角度差為15度以下之結晶方位<111>之存在比率以面積率計成為30~100%之方法如下所述。即,藉由增大Pd被覆層形成後、或形成Pd被覆層與Au表皮層後之加工率,可使導線表面上具有方向性之集合組織(結晶方位與拉絲方向一致之集合組織)成長壯大。具體而言,藉由使Pd被覆層形成後、或形成Pd被覆層與Au表皮層後之加工率成為90%以上,可使測定接合導線表面之結晶方位時的相對於接合導線長度方向而角度差為15度以下之結晶方位<111>之存在比率以面積率計成為30%以上。此處,以「加工率(%)=(加工前之導線剖面面積一加工後之導線剖面面積)/加工前之導線剖面面積×100」表示。 The method of determining the ratio of the crystal orientation <111> having an angular difference of 15 degrees or less with respect to the longitudinal direction of the bonding wire when the crystal orientation of the bonding wire is measured is 30 to 100% in terms of area ratio is as follows. In other words, by increasing the processing ratio after the formation of the Pd coating layer or the formation of the Pd coating layer and the Au skin layer, it is possible to grow the aggregate structure having a directionality on the surface of the wire (the aggregate structure in which the crystal orientation and the wire drawing direction coincide). . Specifically, when the Pd coating layer is formed or the Pd coating layer and the Au skin layer are formed to have a processing ratio of 90% or more, the crystal orientation of the surface of the bonding wire can be measured with respect to the longitudinal direction of the bonding wire. The ratio of the crystal orientation <111> having a difference of 15 degrees or less is 30% or more in terms of area ratio. Here, the "machining rate (%) = (the cross-sectional area of the wire before processing - the cross-sectional area of the wire after processing) / the cross-sectional area of the wire before processing × 100".
測定導線表面之結晶方位時,較佳為使用背向散射電子繞射法(EBSD:Electron Backscattered Diffraction)。EBSD法具有對觀察面之結晶方位進行觀察且可於圖中示出相鄰測定點間之結晶方位之角度差 之特徵,即便為如接合導線般之細線,亦可相對簡便且精度良好地觀察結晶方位。 When measuring the crystal orientation of the surface of the wire, it is preferred to use an EBSD (Electron Backscattered Diffraction). The EBSD method has an observation of the crystal orientation of the observation surface and can show the angular difference of the crystal orientation between adjacent measurement points in the figure. The feature is that the crystal orientation can be observed relatively easily and accurately even in the case of a thin wire such as a bonding wire.
本發明不限定於上述實施形態,可於本發明之主旨之範圍內適當變更。 The present invention is not limited to the above embodiments, and can be appropriately changed within the scope of the gist of the invention.
[實施例] [Examples]
以下一面揭示實施例一面對本發明之實施形態之接合導線進行具體說明。 The following is a detailed description of the bonding wires of the embodiment of the present invention.
(樣品) (sample)
首先,對樣品之製作方法進行說明。成為芯材原材料之Cu係使用純度為99.99質量%以上且其餘部分由不可避免之雜質所構成者。As、Te、Sn、Sb、Bi、Se、Ni、Zn、Rh、In、Ir、Pt、Ga、Ge、Pd、B、P、Mg、Ca、La係使用純度為99質量%以上且其餘部分由不可避免之雜質所構成者。以導線或芯材之組成成為目標組成之方式,調配作為對芯材之添加元素之As、Te、Sn、Sb、Bi、Se、Ni、Zn、Rh、In、Ir、Pt、Ga、Ge、Pd、B、P、Mg、Ca、La。關於As、Te、Sn、Sb、Bi、Se、Ni、Zn、Rh、In、Ir、Pt、Ga、Ge、Pd、B、P、Mg、Ca、La之添加,可以單體形態進行調配,於單體形態下為高熔點元素或添加量極微量之情形時,亦可預先製作包含添加元素之Cu母合金後以成為目標添加量之方式調配。 First, a method of producing a sample will be described. The Cu which is a core material is a purity of 99.99% by mass or more, and the rest is composed of unavoidable impurities. The purity of As, Te, Sn, Sb, Bi, Se, Ni, Zn, Rh, In, Ir, Pt, Ga, Ge, Pd, B, P, Mg, Ca, and La is 99% by mass or more and the rest Made up of unavoidable impurities. As a target composition of the wire or the core material, As, Te, Sn, Sb, Bi, Se, Ni, Zn, Rh, In, Ir, Pt, Ga, Ge, which are added elements to the core material, are formulated. Pd, B, P, Mg, Ca, La. The addition of As, Te, Sn, Sb, Bi, Se, Ni, Zn, Rh, In, Ir, Pt, Ga, Ge, Pd, B, P, Mg, Ca, and La may be formulated in a single form. In the case of a high melting point element or a very small amount in a monomer form, a Cu mother alloy containing an additive element may be prepared in advance and then formulated so as to be a target addition amount.
芯材之Cu合金係藉由如下方式製造,即,將原料裝填於經加工成直徑為3~6mm之圓柱型之碳坩鍋內,使用高頻爐,於真空中或者氮氣或氬氣等惰性氣體環境下加熱至1090~1300℃而熔解後,進行爐冷。對所獲得之3~6mm之合金進行抽拉加工,加工至0.9~1.2mm後,使用模具連續地進行拉絲加工等,藉此製作300~600μm之導線。拉絲時使用市售之潤滑液,拉絲速度係設為20~150m/min。為了將導線表面之氧化膜去除而利用鹽酸進行酸洗處理後,以被覆芯 材之Cu合金整個表面之方式形成1~15μm之Pd被覆層。進而,對一部分導線於Pd被覆層上形成0.05~1.5μm之包含Au與Pd之合金表皮層。Pd被覆層、包含Au與Pd之合金表皮層之形成係採用電解鍍敷法。鍍敷液係使用市售之半導體用鍍敷液。其後,反覆進行200~500℃之熱處理與拉絲加工,藉此將直徑加工至20μm。加工後,以最終斷裂伸長率成為約5~15%之方式,一面流通氮氣或氬氣一面進行熱處理。熱處理方法係一面連續地掠過導線一面進行,且一面流通氮氣或氬氣一面進行。導線之傳送速度係設為20~200m/min,熱處理溫度係設為200~600℃且熱處理時間係設為0.2~1.0秒。 The Cu alloy of the core material is manufactured by filling the raw material into a diameter of In a cylindrical pot of 3 to 6 mm, a high-frequency furnace is used, and it is heated to 1090 to 1300 ° C in a vacuum or an inert gas atmosphere such as nitrogen or argon to be melted, and then furnace-cooled. For what is obtained 3~6mm alloy is drawn and processed to After 0.9 to 1.2 mm, the mold is continuously drawn using a mold, and the like. 300~600μm wire. A commercially available lubricating fluid is used for drawing, and the drawing speed is set to 20 to 150 m/min. In order to remove the oxide film on the surface of the wire and perform pickling treatment with hydrochloric acid, a Pd coating layer of 1 to 15 μm is formed so as to cover the entire surface of the Cu alloy of the core material. Further, a part of the wires was formed on the Pd coating layer to form an alloy skin layer containing Au and Pd of 0.05 to 1.5 μm. The Pd coating layer and the alloy skin layer containing Au and Pd are formed by electrolytic plating. As the plating liquid, a commercially available plating solution for a semiconductor is used. Thereafter, heat treatment and wire drawing were performed at 200 to 500 ° C, whereby the diameter was processed to 20 μm. After the processing, heat treatment is performed while flowing nitrogen gas or argon gas so that the final elongation at break becomes about 5 to 15%. The heat treatment method is carried out while continuously sweeping the wire while flowing nitrogen or argon while flowing. The wire transfer speed is set to 20 to 200 m/min, the heat treatment temperature is set to 200 to 600 ° C, and the heat treatment time is set to 0.2 to 1.0 second.
藉由對Pd被覆層形成後、或形成Pd被覆層與包含Au與Pd之合金表皮層後之加工率進行調整,可對測定接合導線表面之結晶方位時的相對於接合導線長度方向而角度差為15度以下之結晶方位<111>之存在比率(面積率)進行調整。 By adjusting the processing ratio after forming the Pd coating layer or forming the Pd coating layer and the alloy skin layer containing Au and Pd, the angle difference with respect to the longitudinal direction of the bonding wire when measuring the crystal orientation of the bonding wire surface can be measured. The ratio (area ratio) of the crystal orientation <111> of 15 degrees or less was adjusted.
關於Pd被覆層、包含Au與Pd之合金表皮層之濃度分析,一面利用濺擊等自接合導線之表面朝向深度方向切削一面實施歐傑電子分光分析。根據所獲得之深度方向之濃度分佈,求出Pd被覆層厚、包含Au與Pd之合金表皮層厚。 Regarding the concentration analysis of the Pd coating layer and the alloy skin layer containing Au and Pd, the Auger electron spectroscopy was performed while cutting the surface of the bonding wire from the surface of the bonding wire by sputtering or the like. Based on the obtained concentration distribution in the depth direction, the thickness of the Pd coating layer and the thickness of the alloy skin layer containing Au and Pd were determined.
關於下述表1-5中記載之本發明例93~98,芯材係使用純度為99.99質量%以上之Cu,於導線製造步驟之中途,利用電氣鍍敷法使As、Te、Sn、Sb、Bi、Se被覆於導線表面,藉此含有該等元素。因此,表1-5中設有「成分添加方法」欄,關於本發明例99~109記載為「被覆層」。關於表1-1~表1-4全部、及表1-5之「成分添加方法」欄中記載為「芯材」之例,使As、Te、Sn、Sb、Bi、Se含有於芯材中。 In the present invention examples 93 to 98 described in the following Tables 1-5, the core material was made of Cu having a purity of 99.99% by mass or more, and As, Te, Sn, and Sb were electrically deposited by the electroplating method in the middle of the wire manufacturing step. Bi, Se are coated on the surface of the wire to thereby contain the elements. Therefore, the "component addition method" column is provided in Table 1-5, and the present invention examples 99 to 109 are described as "cover layer". For example, in the column of "Component Addition Method" in Table 1-1 to Table 1-4 and "Core Material" in Table 1-5, As, Te, Sn, Sb, Bi, and Se are contained in the core material. in.
關於下述表1-5中記載之本發明例99~109、比較例13、14,使Cu存在於接合導線之最表面。因此,表1-5中設有「導線表面Cu濃 度」欄,記載藉由歐傑電子分光裝置測定接合導線之表面所得之結果。藉由選擇接合導線之熱處理溫度與時間而使最表面含有特定濃度之Cu。關於表1-1~表1-4全部、及表1-5之「導線表面Cu濃度」欄為空欄之例,係設為使最表面不存在Cu之熱處理條件,即便利用歐傑電子分光裝置亦未檢測出Cu。 With respect to Invention Examples 99 to 109 and Comparative Examples 13 and 14 described in the following Tables 1-5, Cu was present on the outermost surface of the bonding wire. Therefore, in Table 1-5, "the surface of the wire is thick. In the column, the results obtained by measuring the surface of the bonding wire by the Auger electronic spectroscopic device are described. The outermost surface contains a specific concentration of Cu by selecting the heat treatment temperature and time of the bonding wires. For the examples in Table 1-1 to Table 1-4 and Table 1-5, the "Cu Concentration on the Conductor Surface" column is an empty column. The heat treatment condition is such that Cu is not present on the outermost surface, even if the Oujie electronic spectroscopic device is used. No Cu was detected.
將依據上述順序所製作之各樣品之構成示於表1-1~表1-5。 The composition of each sample prepared in the above order is shown in Tables 1-1 to 1-5.
(評價方法) (evaluation method)
將導線表面作為觀察面,進行結晶組織之評價。作為評價方法,使用背向散射電子繞射法(EBSD:Electron Backscattered Diffraction)。EBSD法具有對觀察面之結晶方位進行觀察且可於圖中示出相鄰測定點間之結晶方位之角度差之特徵,即便為如接合導線般之細線,亦可相對簡便且精度良好地觀察結晶方位。 The surface of the wire was used as an observation surface to evaluate the crystal structure. As an evaluation method, an EBSD (Electron Backscattered Diffraction) method was used. The EBSD method has a feature of observing the crystal orientation of the observation surface and showing the angular difference of the crystal orientation between adjacent measurement points. Even if it is a thin wire such as a bonding wire, it can be observed relatively easily and accurately. Crystal orientation.
將如導線表面般之曲面作為對象而實施EBSD法之情形時需要注意下列事項。若測定曲率較大之部位,則難以進行高精度之測定。然而,藉由將供於測定之接合導線以平面固定於直線上,並測定該接合導線之中心附近之平坦部,可進行高精度之測定。具體而言,設定為如下測定區域即可。圓周方向之尺寸係以導線長度方向之中心作為軸而設為線徑之50%以下,導線長度方向之尺寸係設為100μm以下。較佳為圓周方向之尺寸係設為線徑之40%以下,導線長度方向之尺寸係設為40μm以下,若如此則可藉由縮短測定時間而提高測定效率。進而為了提高精度,較理想的是對3處以上進行測定而獲得考慮到不均之平均資訊。測定部位只要以不靠近之方式隔開1mm以上即可。 Note the following when implementing the EBSD method with a curved surface like a wire surface as an object. When a portion having a large curvature is measured, it is difficult to perform measurement with high precision. However, the measurement can be performed with high precision by fixing the bonding wire for measurement to a straight line in a plane and measuring the flat portion near the center of the bonding wire. Specifically, it is set as the measurement area as follows. The dimension in the circumferential direction is set to 50% or less of the wire diameter in the center of the longitudinal direction of the wire, and the dimension in the longitudinal direction of the wire is set to 100 μm or less. Preferably, the dimension in the circumferential direction is 40% or less of the wire diameter, and the dimension in the longitudinal direction of the wire is 40 μm or less. Thus, the measurement efficiency can be improved by shortening the measurement time. Further, in order to improve the accuracy, it is preferable to measure three or more places to obtain an average information in consideration of unevenness. The measurement site may be separated by 1 mm or more so as not to be close to each other.
表面<111>方位比率係藉由如下方式求出,即,將可由專用軟體(例如TSL Solutions公司製造之OIM analysis等)特定之所有結晶方位作為母集團,算出相對於接合導線長度方向而角度差為15度以下之結晶方位<111>之存在比率(面積率)。 The surface <111> azimuth ratio is obtained by using all the crystal orientations specified by a dedicated software (for example, OIM analysis manufactured by TSL Solutions, Inc.) as a parent group, and calculating the angular difference with respect to the length direction of the bonding wires. The ratio (area ratio) of the crystal orientation <111> of 15 degrees or less.
關於高溫高濕環境或高溫環境下之球接合部之接合可靠性,製作接合可靠性評價用樣品,進行HAST及HTS評價,根據各試驗中之球接合部之接合壽命進行判定。關於接合可靠性評價用樣品,於通常之金屬框架上之Si基板上成膜厚度0.8μm之Al-1.0%Si-0.5%Cu之合金而形成電極,對所形成之電極使用市售之打線接合機進行球接合,藉由市售之環氧樹脂加以密封而製作樣品。球係一面以0.4~0.6L/min 之流量流通氮氣+5%氫氣一面形成,其大小係設為33~34μm之範圍。 The joint reliability test was performed on the joint reliability of the ball joint portion in a high-temperature, high-humidity environment or a high-temperature environment, and the HAST and HTS evaluations were performed, and the joint life of the ball joint portion in each test was determined. For the sample for bonding reliability evaluation, an alloy of Al-1.0% Si-0.5% Cu having a thickness of 0.8 μm was formed on a Si substrate on a normal metal frame to form an electrode, and a commercially available wire bonding was used for the formed electrode. The machine was ball bonded and sealed by a commercially available epoxy resin to prepare a sample. The ball system is formed by flowing nitrogen gas + 5% hydrogen gas at a flow rate of 0.4 to 0.6 L/min, and the size is set to Range of 33~34μm.
關於HAST評價,使用不飽和型壓力鍋試驗機,將所製作之接合可靠性評價用樣品暴露於溫度130℃、相對濕度85%之高溫高濕環境下,施加5V之偏壓。關於球接合部之接合壽命,每隔48小時對球接合部實施剪切試驗,設定為剪切強度之值成為初期獲得之剪切強度之1/2的時間。高溫高濕試驗後之剪切試驗係藉由酸處理將樹脂去除而使球接合部露出後進行。 With respect to the HAST evaluation, the prepared joint reliability evaluation sample was exposed to a high-temperature and high-humidity environment having a temperature of 130 ° C and a relative humidity of 85% using an unsaturated pressure cooker tester, and a bias voltage of 5 V was applied. Regarding the bonding life of the ball joint portion, the ball joint portion was subjected to a shear test every 48 hours, and the shear strength value was set to be 1/2 of the initial shear strength. The shear test after the high-temperature and high-humidity test was carried out by removing the resin by an acid treatment to expose the ball joint portion.
HAST評價之剪切試驗機係使用DAGE公司製造之試驗機。剪切強度之值係採用隨意選取之球接合部上之10處測定值之平均值。於上述評價中,若接合壽命未達96小時則判斷為實用上有問題而標註記號“×”,若為96小時以上且未達144小時則判斷為可實用但稍有問題而標註記號“△”,若為144小時以上且未達288小時則判斷為實用上無問題而標註記號“○”,若為288小時以上且未達384小時則判斷為優異而標註記號“◎”,若為384小時以上則判斷為特別優異而標註記號“◎◎”,記載於表1之「HAST」欄。 The shear tester evaluated by HAST used a test machine manufactured by DAGE Corporation. The value of the shear strength is the average of the measured values at 10 points on the randomly selected ball joint. In the above evaluation, if the bonding life is less than 96 hours, it is judged that there is a problem in practical use, and the symbol "X" is indicated. If it is 96 hours or more and less than 144 hours, it is judged to be practical but slightly problematic, and the symbol "△" is attached. "If it is 144 hours or more and it is less than 288 hours, it is judged that it is practically no problem and the symbol "○" is attached. If it is 288 hours or more and it is less than 384 hours, it is judged that it is excellent, and the symbol "◎" is attached, and if it is 384. When it is more than an hour, it is judged that it is particularly excellent, and the symbol "◎◎" is attached, and it is described in the "HAST" column of Table 1.
關於HTS評價,使用高溫恆溫器,將所製作之接合可靠性評價用樣品暴露於溫度200℃之高溫環境下。關於球接合部之接合壽命,每隔500小時對球接合部實施剪切試驗,設定為剪切強度之值成為初期所獲得之剪切強度之1/2的時間。高溫高濕試驗後之剪切試驗係藉由酸處理將樹脂去除而使球接合部露出後進行。 Regarding the HTS evaluation, the prepared joint reliability evaluation sample was exposed to a high temperature environment at a temperature of 200 ° C using a high temperature thermostat. Regarding the joint life of the ball joint portion, the ball joint portion was subjected to a shear test every 500 hours, and the shear strength value was set to be 1/2 of the shear strength obtained at the initial stage. The shear test after the high-temperature and high-humidity test was carried out by removing the resin by an acid treatment to expose the ball joint portion.
HTS評價之剪切試驗機係使用DAGE公司製造之試驗機。剪切強度之值係採用隨意選取之球接合部上之10處測定值之平均值。上述評價中,若接合壽命為500小時以上且未達1000小時則判斷為可實用但仍需改善而標註記號“△”,若為1000小時以上且未達3000小時則判斷為實用上無問題而標註記號“○”,若為3000小時以上則判斷為特 別優異而標註記號“◎”。 The shear test machine evaluated by HTS used a test machine manufactured by DAGE Corporation. The value of the shear strength is the average of the measured values at 10 points on the randomly selected ball joint. In the above evaluation, when the bonding life is 500 hours or more and less than 1000 hours, it is judged to be practical, but it is still necessary to be improved, and the symbol "△" is attached. If it is 1000 hours or more and less than 3000 hours, it is judged to be practically problem-free. Mark the mark "○", if it is more than 3000 hours, it is judged to be special Don't be excellent and mark it with "◎".
關於球形成性(FAB形狀)之評價,採集進行接合前之球進行觀察,判定於球表面有無氣泡、原本呈圓球狀之球有無變形。將產生上述任一情況之情形判斷為不良。關於球之形成,為了抑制熔融步驟中之氧化,一面以0.5L/min之流量吹送氮氣一面進行。球之大小係設為34μm。於一條件下觀察50個球。觀察時使用SEM。球形成性之評價中,產生5個以上之不良之情形時判斷為有問題而標註記號“×”,不良為3~4個之情形時判斷為可實用但稍有問題而標註記號“△”,不良為1~2個之情形時判斷為無問題而標註記號“○”,未產生不良之情形時判斷為優異而標註記號“◎”,記載於表1之「FAB形狀」欄。 Regarding the evaluation of the ball formation property (FAB shape), the ball before the bonding was collected and observed, and it was determined whether or not the ball on the surface of the ball was deformed by the ball having the original spherical shape. The case where any of the above cases is caused is judged to be bad. The formation of the ball was carried out while blowing nitrogen gas at a flow rate of 0.5 L/min in order to suppress oxidation in the melting step. The size of the ball is set to 34 μm. 50 balls were observed under one condition. SEM was used for observation. In the evaluation of the ball formability, when five or more defects are caused, it is judged that there is a problem, and the symbol "X" is marked. When the defect is 3 to 4, it is judged to be practical but a problem is marked with the symbol "△". When the number of defects is 1 or 2, it is judged that there is no problem and the symbol "○" is attached. If no defect occurs, it is judged to be excellent, and the symbol "◎" is attached, and it is described in the "FAB shape" column of Table 1.
關於導線接合部之楔形接合性之評價,於引線框架之引線部分接合1000根導線,根據接合部之剝離之發生頻度而判定。引線框架係使用經1~3μm之鍍Ag處理之Fe-42原子%Ni合金引線框架。該評價中,設想較通常更嚴酷之接合條件,將平台溫度設定為低於一般設定溫度域之150℃。上述評價中,產生11個以上之不良之情形時判斷為有問題而標註記號“×”,不良為6~10個之情形時判斷為可實用但稍有問題而標註記號“△”,不良為1~5個之情形時判斷為無問題而標註記號“○”,未產生不良之情形時判斷為優異而標註記號“◎”,記載於表1之「楔形接合性」欄。 Regarding the evaluation of the wedge bondability of the wire bonding portion, 1000 lead wires were joined to the lead portion of the lead frame, and it was determined based on the frequency of occurrence of peeling of the joint portion. The lead frame used was a Fe-42 atom% Ni alloy lead frame treated with Ag to 1 to 3 μm. In this evaluation, it is assumed that the bonding conditions are more severe than usual, and the platform temperature is set to be 150 ° C lower than the general set temperature range. In the above evaluation, when 11 or more defects are caused, it is judged that there is a problem, and the symbol "X" is indicated. When the defect is 6 to 10, it is judged to be practical, but the problem is marked with "△", and the defect is In the case of 1 to 5, it is judged that there is no problem and the symbol "○" is attached. When no defect occurs, it is judged to be excellent, and the symbol "◎" is attached, and it is described in the "wedge bondability" column of Table 1.
關於球接合部之壓塌形狀之評價,對經接合之球接合部自其正上方進行觀察,根據其正圓性而判定。接合對象係使用於Si基板上成膜厚度1.0μm之Al-0.5%Cu之合金所得之電極。觀察係使用光學顯微鏡,於一條件下觀察200處。將與正圓偏差較大之橢圓狀者、變形具有異向性者判斷為球接合部之壓塌形狀不良。上述評價中,產生6個以上之不良之情形時判斷為有問題而標註記號“×”,不良為4~5個 之情形時判斷為可實用但稍有問題而標註記號“△”,不良為1~3個之情形時判斷為無問題而標註記號“○”,均獲得良好正圓性之情形時判斷為特別優異而標註記號“◎”,記載於表1之「壓塌形狀」欄。 Regarding the evaluation of the collapsed shape of the ball joint portion, the joined ball joint portion was observed from the immediately upper side thereof, and was determined based on its roundness. The bonding target was an electrode obtained by forming an alloy of Al-0.5% Cu having a thickness of 1.0 μm on a Si substrate. The observation system was observed at 200 places under one condition using an optical microscope. It is judged that the elliptical shape having a large deviation from the perfect circle and the anisotropy of the deformation have a collapsed shape of the ball joint portion. In the above evaluation, when there are six or more cases of defects, it is judged that there is a problem, and the symbol "X" is marked, and the defect is 4 to 5 pieces. In the case of the case, it is judged to be practical but slightly problematic, and the symbol "△" is marked. When the defect is 1 to 3, it is judged that there is no problem and the symbol "○" is marked, and when it is good in roundness, it is judged to be special. The mark "◎" which is excellent and is marked in the "collapse shape" column of Table 1.
[偏斜] [skew]
於評價用引線框架上以迴路長度5mm、迴路高度0.5mm接合100根導線。作為評價方法,自晶片水平方向觀察導線直立部,以通過球接合部中心之垂線與導線直立部之間隔為最大時之間隔(偏斜間隔)進行評價。偏斜間隔小於導線徑之情形時判斷為偏斜良好,大於導線徑之情形時由於直立部傾斜故判斷為偏斜不良。利用光學顯微鏡觀察100根經接合之導線,對偏斜不良之根數進行計數。產生7個以上之不良之情形時判斷為有問題而標註記號“×”,不良為4~6個之情形時判斷為可實用但稍有問題而標註記號“△”,不良為1~3個之情形時判斷為無問題而標註記號“○”,未產生不良之情形時判斷為優異而標註記號“◎”,記載於表1之「偏斜」欄。 100 wires were joined to the evaluation lead frame with a loop length of 5 mm and a loop height of 0.5 mm. As an evaluation method, the wire upright portion was observed from the horizontal direction of the wafer, and was evaluated by the interval (offset interval) at which the distance between the vertical line of the ball joint portion and the wire upright portion was the largest. When the skew interval is smaller than the wire diameter, it is judged that the skew is good, and when it is larger than the wire diameter, it is judged to be poorly skewed due to the inclination of the upright portion. The 100 bonded wires were observed with an optical microscope, and the number of skewed defects was counted. When there are 7 or more defects, it is judged that there is a problem and the symbol "X" is marked. If the defect is 4-6, it is judged to be practical, but the problem is marked with "△", and the defect is 1~3. In the case of the case, it is judged that there is no problem and the symbol "○" is attached. When there is no defect, it is judged to be excellent, and the symbol "◎" is attached, and it is described in the "skew" column of Table 1.
(評價結果) (Evaluation results)
本發明例1~109之接合導線具有Cu合金芯材、與形成於Cu合金芯材之表面之Pd被覆層,接合導線包含選自As、Te、Sn、Sb、Bi、Se中之至少1種以上之元素,上述元素相對於導線整體之濃度合計為0.1~100質量ppm。確認到藉此本發明例1~109之接合導線於溫度130℃、相對濕度85%之高溫高濕環境下之HAST試驗中,可獲得球接合部可靠性。 The bonding wires of Inventive Examples 1 to 109 have a Cu alloy core material and a Pd coating layer formed on the surface of the Cu alloy core material, and the bonding wires include at least one selected from the group consisting of As, Te, Sn, Sb, Bi, and Se. In the above elements, the total concentration of the above elements with respect to the entire wire is 0.1 to 100 ppm by mass. It was confirmed that the bonding wires of Examples 1 to 109 of the present invention were obtained in a HAST test in a high-temperature and high-humidity environment at a temperature of 130 ° C and a relative humidity of 85%, and the ball joint reliability was obtained.
另一方面,比較例1、2、4~6、11~14中,上述元素濃度超出下限,於HAST試驗中無法獲得球接合部可靠性。比較例3、7~10中,上述元素濃度超出上限,FAB形狀不良。比較例1、3、5~10中,<111>結晶方位之面積率超出本發明較佳範圍,偏斜為“△”。 On the other hand, in Comparative Examples 1, 2, 4 to 6, and 11 to 14, the above element concentration exceeded the lower limit, and the ball joint reliability was not obtained in the HAST test. In Comparative Examples 3 and 7 to 10, the above element concentration exceeded the upper limit, and the FAB shape was poor. In Comparative Examples 1, 3, and 5 to 10, the area ratio of the <111> crystal orientation was out of the preferred range of the present invention, and the skew was "?".
關於在Pd被覆層上進而具有包含Au與Pd之合金表皮層之本發明例,確認到藉由包含Au與Pd之合金表皮層之層厚為0.0005~0.050μm,可獲得優異之楔形接合性。 In the example of the present invention which further has an alloy skin layer containing Au and Pd on the Pd coating layer, it has been confirmed that the layer thickness of the alloy skin layer containing Au and Pd is 0.0005 to 0.050 μm, whereby excellent wedge bondability can be obtained.
關於本發明例27~92、100、102、104~109,確認到藉由接合導線進而包含選自Ni、Zn、Rh、In、Ir、Pt、Ga、Ge、Pd中之至少1種以上之元素,除Pd以外之上述元素相對於導線整體之濃度分別為0.011~1.2質量%,且Cu合金芯材所含之Pd之濃度為0.05~1.2質量%,由HTS評價所得之球接合部高溫可靠性良好。 In the examples 27 to 92, 100, 102, and 104 to 109 of the present invention, at least one selected from the group consisting of Ni, Zn, Rh, In, Ir, Pt, Ga, Ge, and Pd is further included in the bonding wire. The concentration of the element other than Pd relative to the entire wire is 0.011 to 1.2% by mass, and the concentration of Pd contained in the Cu alloy core material is 0.05 to 1.2% by mass, and the ball joint portion obtained by HTS evaluation is high in temperature. Good sex.
本發明例28~92之一部分中,藉由接合導線進而包含選自B、P、Mg、Ca、La中之至少1種以上之元素,且上述元素相對於導線整體之濃度分別為1~100質量ppm,FAB形狀良好,並且楔形接合性良好。 In one of the examples 28 to 92 of the present invention, at least one element selected from the group consisting of B, P, Mg, Ca, and La is further contained by the bonding wire, and the concentration of the element relative to the entire wire is 1 to 100, respectively. The mass ppm, the FAB shape is good, and the wedge bondability is good.
本發明例99~109中,導線含有As、Te、Sn、Sb、Bi、Se,並且於導線之最表面存在Cu。藉此,本發明例99、101、103、105、106、108、109之HAST評價結果為◎◎或◎,使最表面存在Cu之效果顯現。本發明例100、102、104、107中,進而導線之Cu之純度低至2N以下,HAST評價結果均為◎◎而極良好。另一方面,該等本發明例中關於楔形接合性觀察到些許降低。 In the inventive examples 99 to 109, the wires contained As, Te, Sn, Sb, Bi, and Se, and Cu was present on the outermost surface of the wires. As a result, the HAST evaluation results of Examples 99, 101, 103, 105, 106, 108, and 109 of the present invention were ◎ ◎ or ◎, and the effect of Cu on the outermost surface was exhibited. In Examples 100, 102, 104, and 107 of the present invention, the purity of Cu of the wire was as low as 2 N or less, and the HAST evaluation results were all excellent. On the other hand, in the examples of the present invention, a slight decrease was observed with respect to the wedge bondability.
比較例13、14中,導線不含As、Te、Sn、Sb、Bi、Se,另一方面,導線之最表面存在Cu,因此不僅HAST評價而且HTS評價結果亦不良,FAB形狀、壓塌形狀亦不良,進而楔形接合性、偏斜亦劣化。 In Comparative Examples 13 and 14, the wires did not contain As, Te, Sn, Sb, Bi, and Se. On the other hand, Cu was present on the outermost surface of the wire, so that not only HAST evaluation but also HTS evaluation results were poor, FAB shape and collapse shape. Also bad, and the wedge bondability and deflection are also deteriorated.

Claims (10)

  1. 一種半導體裝置用接合導線,其係具有Cu合金芯材、與形成於上述Cu合金芯材之表面之Pd被覆層者,其特徵在於:上述接合導線包含選自As、Te中之至少1種以上之元素,上述元素相對於導線整體之濃度合計為0.1質量ppm以上且100質量ppm以下。 A bonding wire for a semiconductor device, comprising a Cu alloy core material and a Pd coating layer formed on a surface of the Cu alloy core material, wherein the bonding wire includes at least one selected from the group consisting of As and Te. In the element, the total concentration of the above elements with respect to the entire wire is 0.1 mass ppm or more and 100 mass ppm or less.
  2. 如請求項1之半導體裝置用接合導線,其中選自As、Te中之至少1種以上之元素相對於導線整體之濃度合計為1質量ppm以上且100質量ppm以下。 The bonding wire for a semiconductor device according to claim 1, wherein a concentration of at least one element selected from the group consisting of As and Te is 1 ppm by mass or more and 100 ppm by mass or less with respect to the total concentration of the wire.
  3. 如請求項1之半導體裝置用接合導線,其中上述Pd被覆層之厚度為0.015μm以上且0.150μm以下。 The bonding wire for a semiconductor device according to claim 1, wherein the thickness of the Pd coating layer is 0.015 μm or more and 0.150 μm or less.
  4. 如請求項1之半導體裝置用接合導線,其於上述Pd被覆層上進而具有包含Au與Pd之合金表皮層。 The bonding wire for a semiconductor device according to claim 1, further comprising an alloy skin layer containing Au and Pd on the Pd coating layer.
  5. 如請求項4之半導體裝置用接合導線,其中上述包含Au與Pd之合金表皮層之厚度為0.0005μm以上且0.050μm以下。 The bonding wire for a semiconductor device according to claim 4, wherein the thickness of the alloy skin layer containing Au and Pd is 0.0005 μm or more and 0.050 μm or less.
  6. 如請求項1之半導體裝置用接合導線,其中上述接合導線進而包含選自Ni、Zn、Rh、In、Ir、Pt、Ga、Ge中之至少1種以上之元素,上述元素相對於導線整體之濃度分別為0.011質量%以上且1.2質量%以下。 The bonding wire for a semiconductor device according to claim 1, wherein the bonding wire further includes at least one element selected from the group consisting of Ni, Zn, Rh, In, Ir, Pt, Ga, and Ge, and the element is substantially the same as the wire. The concentration is 0.011% by mass or more and 1.2% by mass or less, respectively.
  7. 如請求項1之半導體裝置用接合導線,其中上述Cu合金芯材包含Pd,上述Cu合金芯材所含之Pd之濃度為0.05質量%以上且1.2質量%以下。 The bonding wire for a semiconductor device according to claim 1, wherein the Cu alloy core material contains Pd, and the concentration of Pd contained in the Cu alloy core material is 0.05% by mass or more and 1.2% by mass or less.
  8. 如請求項1之半導體裝置用接合導線,其中上述接合導線進而包含選自B、P、Mg、Ca、La中之至少1種以上之元素,上述元素 相對於導線整體之濃度分別為1質量ppm以上且100質量ppm以下。 The bonding wire for a semiconductor device according to claim 1, wherein the bonding wire further contains at least one element selected from the group consisting of B, P, Mg, Ca, and La, and the element The concentration with respect to the entire wire is 1 mass ppm or more and 100 mass ppm or less.
  9. 如請求項1之半導體裝置用接合導線,其中於測定上述接合導線表面之結晶方位時之測定結果中,相對於上述接合導線長度方向而角度差為15度以下之結晶方位<111>之存在比率為30%以上且100%以下。 The bonding wire for a semiconductor device according to claim 1, wherein in the measurement result of measuring the crystal orientation of the surface of the bonding wire, the existence ratio of the crystal orientation <111> having an angular difference of 15 degrees or less with respect to the longitudinal direction of the bonding wire It is 30% or more and 100% or less.
  10. 如請求項1至9中任一項之半導體裝置用接合導線,其中於上述接合導線之最表面存在Cu。 The bonding wire for a semiconductor device according to any one of claims 1 to 9, wherein Cu is present on the outermost surface of the bonding wire.
TW104131499A 2015-05-26 2015-09-23 Connecting wires for semiconductor devices TWI550639B (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2015106368 2015-05-26
TW104118466 2015-06-05
TW104131499A TWI550639B (en) 2015-05-26 2015-09-23 Connecting wires for semiconductor devices

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
TW104131499A TWI550639B (en) 2015-05-26 2015-09-23 Connecting wires for semiconductor devices

Publications (2)

Publication Number Publication Date
TWI550639B true TWI550639B (en) 2016-09-21
TW201642279A TW201642279A (en) 2016-12-01

Family

ID=57445156

Family Applications (2)

Application Number Title Priority Date Filing Date
TW105121817A TWI628671B (en) 2015-05-26 2015-09-23 Bonding wire for semiconductor device
TW104131499A TWI550639B (en) 2015-05-26 2015-09-23 Connecting wires for semiconductor devices

Family Applications Before (1)

Application Number Title Priority Date Filing Date
TW105121817A TWI628671B (en) 2015-05-26 2015-09-23 Bonding wire for semiconductor device

Country Status (1)

Country Link
TW (2) TWI628671B (en)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6120693A (en) * 1984-07-06 1986-01-29 Toshiba Corp Bonding wire
JPS6152332A (en) * 1984-08-21 1986-03-15 Toshiba Corp Bonding wire
JPS6152333A (en) * 1984-08-21 1986-03-15 Toshiba Corp Bonding wire
JP2004064033A (en) * 2001-10-23 2004-02-26 Sumitomo Electric Wintec Inc Bonding wire
CN101828255A (en) * 2007-12-03 2010-09-08 新日铁高新材料株式会社 Bonding wire for semiconductor devices
JP2011035020A (en) * 2009-07-30 2011-02-17 Nippon Steel Materials Co Ltd Bonding wire for semiconductor
JP2011077254A (en) * 2009-09-30 2011-04-14 Nippon Steel Materials Co Ltd Bonding wire for semiconductor
CN102459668A (en) * 2009-06-24 2012-05-16 新日铁高新材料株式会社 Copper alloy bonding wire for semiconductor

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI369748B (en) * 2010-07-16 2012-08-01 Nippon Steel Materials Co Ltd

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6120693A (en) * 1984-07-06 1986-01-29 Toshiba Corp Bonding wire
JPS6152332A (en) * 1984-08-21 1986-03-15 Toshiba Corp Bonding wire
JPS6152333A (en) * 1984-08-21 1986-03-15 Toshiba Corp Bonding wire
JP2004064033A (en) * 2001-10-23 2004-02-26 Sumitomo Electric Wintec Inc Bonding wire
CN101828255A (en) * 2007-12-03 2010-09-08 新日铁高新材料株式会社 Bonding wire for semiconductor devices
CN102459668A (en) * 2009-06-24 2012-05-16 新日铁高新材料株式会社 Copper alloy bonding wire for semiconductor
JP2011035020A (en) * 2009-07-30 2011-02-17 Nippon Steel Materials Co Ltd Bonding wire for semiconductor
JP2011077254A (en) * 2009-09-30 2011-04-14 Nippon Steel Materials Co Ltd Bonding wire for semiconductor

Also Published As

Publication number Publication date
TW201642279A (en) 2016-12-01
TW201642282A (en) 2016-12-01
TWI628671B (en) 2018-07-01

Similar Documents

Publication Publication Date Title
JP5349382B2 (en) Bonding wire for ball bonding for semiconductors
EP2960931B1 (en) Copper bond wire
JP5246314B2 (en) Copper alloy bonding wire for semiconductors
CN101925992B (en) Bonding wire for semiconductor
JP4349641B1 (en) Coated copper wire for ball bonding
JP5073759B2 (en) Bonding wires for semiconductor devices
KR101057271B1 (en) Bonding Wires for Semiconductor Devices
KR101030384B1 (en) Bonding wire for semiconductor devices
JP5616739B2 (en) Multilayer copper bonding wire bonding structure
KR101707244B1 (en) Bonding wire for semiconductor
JP5550369B2 (en) Copper bonding wire for semiconductor and its bonding structure
DE112015004364B4 (en) Bonding wire for semiconductor device
JP5868968B2 (en) Method for manufacturing an electronic device
US8247911B2 (en) Wire bonding structure and method for forming same
JP4904252B2 (en) Bonding wires for semiconductor devices
CN106489199B (en) Bonding wire for semiconductor device
TW201037777A (en) Bonding wire
JP5964534B1 (en) Bonding wires for semiconductor devices
TW201430977A (en) Coated wire for bonding applications
JP4885117B2 (en) Bonding wires for semiconductor devices
JP5497360B2 (en) Bonding wire for semiconductor
CN105830205B (en) Bonding wire for semiconductor device
JP4672373B2 (en) Bonding wires for semiconductor devices
KR101940894B1 (en) Lead-free eutectic solder alloy comprising zinc as the main component and aluminum as an alloying metal
EP3470168B1 (en) Process for the manufacture of a coated wire