JP2019036602A - Junction structure and method for manufacturing the same - Google Patents

Junction structure and method for manufacturing the same Download PDF

Info

Publication number
JP2019036602A
JP2019036602A JP2017155965A JP2017155965A JP2019036602A JP 2019036602 A JP2019036602 A JP 2019036602A JP 2017155965 A JP2017155965 A JP 2017155965A JP 2017155965 A JP2017155965 A JP 2017155965A JP 2019036602 A JP2019036602 A JP 2019036602A
Authority
JP
Japan
Prior art keywords
metal
layer
joined
bonding
bonded
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
JP2017155965A
Other languages
Japanese (ja)
Inventor
臼井　正則
Masanori Usui
正則 臼井
宏文 伊藤
Hirofumi Ito
宏文 伊藤
佐藤　敏一
Toshiichi Sato
敏一 佐藤
智幸 庄司
Tomoyuki Shoji
智幸 庄司
林太郎 淺井
Rintaro Asai
林太郎 淺井
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Toyota Central R&D Labs Inc
Original Assignee
Toyota Motor Corp
Toyota Central R&D Labs Inc
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
Application filed by Toyota Motor Corp, Toyota Central R&D Labs Inc filed Critical Toyota Motor Corp
Priority to JP2017155965A priority Critical patent/JP2019036602A/en
Publication of JP2019036602A publication Critical patent/JP2019036602A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means 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
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/2612—Auxiliary members for layer connectors, e.g. spacers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means 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
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/31—Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L2224/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
    • H01L2224/83—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a layer connector
    • H01L2224/8338—Bonding interfaces outside the semiconductor or solid-state body
    • H01L2224/83385—Shape, e.g. interlocking features

Landscapes

  • Die Bonding (AREA)

Abstract

To provide a junction structure capable of ensuring high reliability even under an action of power cycle stress.SOLUTION: The junction structure includes a junction portion (4) for SLID bonding a first member (10) and a second member (20). The junction portion includes: a covering layer (11) made of a first metal provided on at least the first member side on a surface to be joined of the first member; a junction layer (414) consisting of an intermetallic compound (IMC) of the first metal and a second metal having a melting point lower than that of the first metal and being joined to the covering layer; a reinforcing layer (30) made of a third metal that is more ductile than the first metal; an intermediate layer (4311) made of the first metal and joined to the junction layer and the reinforcing layer; and a guiding portion (4014), consisting of IMC, directly connected to the reinforcing layer without an intermediate layer in at least a central region of the surface to be joined of the first member. Cracks and the like are easily generated in the reinforcing layer by the guiding portion, stress acting on the first member is reduced, and warpage, damage, and the like of the first member are suppressed.SELECTED DRAWING: Figure 1

Description

本発明は、パワーサイクルストレスが作用する環境下で使用されても、信頼性等を確保できる接合構造体等に関する。   The present invention relates to a joined structure and the like that can ensure reliability and the like even when used in an environment where power cycle stress acts.

モータ駆動用インバータ等には、ＩＧＢＴ（Insulated Gate Bipolar Transistor）等のデバイス（半導体素子）を、絶縁基板や電極等の上に実装したパワーモジュールが用いられる。   For a motor drive inverter or the like, a power module in which a device (semiconductor element) such as an IGBT (Insulated Gate Bipolar Transistor) is mounted on an insulating substrate or an electrode is used.

パワーモジュールの信頼性を確保するため、デバイスの作動中に生じる発熱をヒートシンクや冷却器等を介して効率的に放熱させると共に、その接合部（周辺）に生じる熱膨張係数（ＣＴＥ：coefficient of thermal expansion）差（ＣＴＥ不整合）に起因した熱応力を緩和したり、その熱応力に対する耐久性（耐熱疲労性）を高めることが重要となる。   In order to ensure the reliability of the power module, heat generated during device operation is efficiently dissipated through a heat sink, a cooler, etc., and a coefficient of thermal expansion (CTE) generated at the joint (periphery) It is important to alleviate thermal stress due to expansion (CTE mismatch) and to improve durability against thermal stress (heat fatigue resistance).

また、ＳｉＣ、ＧａＮ、Ｇａ２Ｏ３等からなる次世代のデバイスを用いる場合、従来以上に高温域（例えば１５０℃以上）で使用されることが予想されるため、接合部には一層高い耐熱性も要求される。特に車載用パワーモジュールでは、搭載自由度の向上や軽量化を図るために小型化が進められているため、デバイスの動作温度はさらに上昇傾向にある。 In addition, when a next-generation device made of SiC, GaN, Ga 2 O 3 or the like is used, it is expected to be used in a higher temperature range (for example, 150 ° C. or higher) than before, so that the joint portion has higher heat resistance Sex is also required. In particular, in an in-vehicle power module, since the downsizing is promoted in order to improve the mounting flexibility and reduce the weight, the operating temperature of the device is further increasing.

このような事情の下、パワーモジュールのさらなる信頼性の向上等を図れる接合構造体に関する提案が下記の特許文献でなされている。   Under such circumstances, the following patent document proposes a joint structure that can further improve the reliability of the power module.

ＷＯ２０１７−０８６３２４号公報WO2017-086324

特許文献１は、低融点金属と高融点金属を反応させ、低融点金属よりも高融点な金属間化合物（ＩＭＣ：intermetallic compound）を生成させて、その金属間化合物により部材間の接合を行う固液相互拡散接合（単に「ＳＬＩＤ（Solid Liquid InterDiffusion）接合」という。）を行うことを前提に、熱応力緩和性や耐熱疲労性の向上を図れる接合構造体を提案している。   In Patent Document 1, a low melting point metal and a high melting point metal are reacted to generate an intermetallic compound (IMC) having a melting point higher than that of the low melting point metal, and the members are joined by the intermetallic compound. On the premise of performing liquid interdiffusion bonding (simply referred to as “SLID (Solid Liquid InterDiffusion) bonding”), a bonding structure capable of improving thermal stress relaxation and heat fatigue resistance is proposed.

具体的にいうと、第１部材（半導体素子）の接合層の外周囲に、高延性な金属からなる補強層（Ａｌ層）へ直結する誘導を設けることを提案している。これにより、第１部材の接合層の外周囲から補強層内へ熱応力が誘導される。その結果、冷熱サイクル下で発生し易いクラックは補強層内で優先的に発生、伝播することになり、上述した熱応力の緩和や耐熱疲労性の向上が図られる。   Specifically, it has been proposed to provide an induction directly connected to a reinforcing layer (Al layer) made of a highly ductile metal on the outer periphery of the bonding layer of the first member (semiconductor element). Thereby, thermal stress is induced from the outer periphery of the bonding layer of the first member into the reinforcing layer. As a result, cracks that are likely to occur under a cooling / heating cycle are preferentially generated and propagated in the reinforcing layer, and the above-described relaxation of thermal stress and improvement of thermal fatigue resistance are achieved.

確かに、特許文献１に記載の接合構造体は、ある程度継続した高温下と低温下に繰り返し曝される冷熱サイクル下で生じる熱応力（「温度サイクルストレス」という。）に対して有効である。しかし、その接合構造体でも、パワーサイクルストレスに対しては必ずしも十分とはいえない。パワーサイクルストレスとは、通電と遮断が繰り返される半導体素子に生じる周期的な熱応力である。特に、高温となり易い半導体素子の中央域で、温度分布や温度勾配に応じた大きな熱応力（パワーサイクルストレス）が生じ易い。   Certainly, the joint structure described in Patent Document 1 is effective against thermal stress (referred to as “temperature cycle stress”) generated under a cooling cycle that is repeatedly exposed to a high temperature and a low temperature that continue to some extent. However, even the bonded structure is not necessarily sufficient for power cycle stress. The power cycle stress is a periodic thermal stress generated in a semiconductor element that is repeatedly energized and interrupted. In particular, a large thermal stress (power cycle stress) corresponding to the temperature distribution and temperature gradient is likely to occur in the central region of the semiconductor element that tends to be high temperature.

大きなパワーサイクルストレスが作用すると、半導体素子は図５に示すように上方に凸状に反り易くなり、接合不良のみならず、半導体素子の損傷等も生じ得る。   When a large power cycle stress acts, the semiconductor element is likely to warp upward as shown in FIG. 5, and not only poor bonding but also damage to the semiconductor element may occur.

本発明はこのような事情に鑑みて為されたものであり、パワーサイクルストレスが作用する場合でも、信頼性を確保できる接合構造体等を提供することを目的とする。   The present invention has been made in view of such circumstances, and an object of the present invention is to provide a joined structure and the like that can ensure reliability even when power cycle stress acts.

本発明者はこの課題を解決すべく鋭意研究した結果、第１部材上から補強層へ直結する誘導部を、第１部材の被接合面の少なくとも中央域に設けることにより、パワーサイクルストレスが作用し得る第１部材にクラック等が導入されないようにすることに成功した。この成果を発展させることにより、以降に述べる本発明を完成するに至った。   As a result of diligent research to solve this problem, the present inventor has provided a guide portion directly connected to the reinforcing layer from the first member at least in the central region of the bonded surface of the first member, so that power cycle stress acts. It succeeded in preventing a crack etc. from being introduced into the 1st member which can do. By developing this result, the present invention described below has been completed.

《接合構造体》
（１）本発明の接合構造体は、第１部材と、該第１部材と接合され得る第２部材と、該第１部材と該第２部材を接合する接合部と、を備える接合構造体であって、前記接合部は、少なくとも第１部材側に、前記第１部材の被接合面上に設けられた第１金属からなる被覆層と、該第１金属と該第１金属よりも低融点な第２金属との金属間化合物からなり該被覆層に接合している接合層と、該第１金属よりも高延性な第３金属からなる補強層と、該第１金属からなり該接合層と該補強層とに接合している中間層と、該金属間化合物からなると共に該第１部材の被接合面の少なくとも中央域で該中間層を介さずに該補強層に直結している誘導部と、を有する。 <Joint structure>
(1) The joining structure of the present invention includes a first member, a second member that can be joined to the first member, and a joining portion that joins the first member and the second member. The joining portion includes a coating layer made of a first metal provided on a joined surface of the first member at least on the first member side, and a lower layer than the first metal and the first metal. A joining layer made of an intermetallic compound with a second metal having a melting point and joined to the coating layer, a reinforcing layer made of a third metal having a higher ductility than the first metal, and the joining made of the first metal An intermediate layer bonded to the reinforcing layer and the reinforcing layer, and is directly connected to the reinforcing layer without the intermediate layer at least in the central region of the surface to be bonded of the first member, with the intermetallic compound. And a guiding portion.

（２）本発明の接合構造体は、第１部材と第２部材をＳＬＩＤ接合する接合部が、第１部材の被接合面の少なくとも中央域において、中間層を介さずに補強層に直結された誘導部を有する。この誘導部により、第１部材の中央域付近に作用する大きなパワーサイクルストレスが補強層へ効果的に誘導される。このため、第１部材や接合層にクラックが生じることが回避され、第１部材や接合層の損傷が回避され、接合構造体の信頼性が確保される。 (2) In the bonded structure according to the present invention, the bonding portion for performing the SLID bonding of the first member and the second member is directly connected to the reinforcing layer without an intermediate layer at least in the central region of the bonded surface of the first member. It has an induction part. By this guiding portion, a large power cycle stress acting near the central region of the first member is effectively induced to the reinforcing layer. For this reason, the occurrence of cracks in the first member and the bonding layer is avoided, damage to the first member and the bonding layer is avoided, and the reliability of the bonded structure is ensured.

仮にクラックが生じるとき、そのクラックは第１部材等ではなく補強層で生じる。これにより、第１部材や接合層に加わるパワーサイクルストレスは緩和され、その反りも抑制される。なお、パワーサイクルストレスの変動により補強層中のクラックは進展する可能性がある。しかし、その進展方向は（被）接合面の略法線方向である。このため補強層に生じるクラックは、第１部材から第２部材側への熱伝導特性（放熱性）を低下させることは少ない。   If a crack occurs, the crack occurs not in the first member or the like but in the reinforcing layer. Thereby, the power cycle stress applied to the first member and the bonding layer is relieved and the warpage is also suppressed. Note that cracks in the reinforcing layer may develop due to fluctuations in power cycle stress. However, the progress direction is a substantially normal direction of the (to-be-joined) surface. For this reason, the crack which arises in a reinforcement layer rarely reduces the heat conduction characteristic (heat dissipation) from the 1st member to the 2nd member side.

また、本発明に係る補強層は、高延性（高靱性）な金属（第３金属）からなる。このため補強層内におけるクラックの進展は遅く、補強層の塑性変形等も加わって、第１部材や接合部に作用するパワーサイクルストレス等を十分に緩和する。   The reinforcing layer according to the present invention is made of a highly ductile (high toughness) metal (third metal). For this reason, the progress of cracks in the reinforcing layer is slow, and plastic deformation of the reinforcing layer is also added, thereby sufficiently mitigating power cycle stress and the like acting on the first member and the joint.

ちなみに、本発明に係る接合層や誘導部は高融点な金属間化合物（ＩＭＣ）からなる。このため、接合構造体（特に接合部近傍）の温度が接合工程時の加熱温度以上になっても、本発明の接合構造体は、安定した接合状態を維持し、優れた耐熱性を発揮する。   Incidentally, the bonding layer and the induction part according to the present invention are made of a high melting point intermetallic compound (IMC). For this reason, even if the temperature of the bonded structure (particularly in the vicinity of the bonded portion) is equal to or higher than the heating temperature during the bonding process, the bonded structure of the present invention maintains a stable bonded state and exhibits excellent heat resistance. .

《接合構造体の製造方法》
（１）本発明は接合構造体の製造方法としても把握できる。すなわち本発明は、第１部材と第２部材の間で挟持された接合材を加熱して該第１部材と該第２部材を接合する接合工程を備える接合構造体の製造方法であって、前記第１部材は、被接合面上の少なくとも一部に第１金属からなる被覆層を有し、前記接合材は、少なくとも該第１部材側に、該第１金属からなる第１層と、該第１層の該被覆層側にあり該第１金属よりも低融点な第２金属からなる第２層と、該第１層の他面側にあり該第１金属よりも高延性な第３金属からなる第３層とを少なくとも有すると共に、該第１部材の被接合面の少なくとも中央域に対応する位置に、少なくとも該第１層中で該第１金属が形成されていない開溝部を備え、前記接合工程は、該第２金属の融点以上であって該第２金属と該第１金属が反応して金属間化合物を生成する反応温度以上に該接合材を加熱する工程である接合構造体の製造方法でもよい。 << Manufacturing Method of Bonded Structure >>
(1) The present invention can also be grasped as a method for manufacturing a joined structure. That is, this invention is a manufacturing method of the joining structure provided with the joining process which heats the joining material clamped between the 1st member and the 2nd member, and joins this 1st member and this 2nd member, The first member has a coating layer made of a first metal on at least a part of a surface to be joined, and the joining material has at least a first layer made of the first metal on the first member side, A second layer comprising a second metal having a lower melting point than the first metal on the coating layer side of the first layer; and a second layer having a higher ductility than the first metal on the other surface side of the first layer. At least a third layer made of three metals, and at least a groove portion where the first metal is not formed in the first layer at a position corresponding to at least the central region of the bonded surface of the first member. And the bonding step has a melting point of the second metal or higher, and the second metal and the first metal react to form an intermetallic compound. Or in the manufacturing method of the bonded structure is a step of heating the the bonding material or the reaction temperature to produce a.

（２）本発明の製造方法のように、第１金属が形成されていない開溝部を設けることにより、第１部材の中央域に対応する所望位置に誘導部が確実に形成される。この理由は次のように考えられる。 (2) By providing the open groove portion where the first metal is not formed as in the manufacturing method of the present invention, the guide portion is reliably formed at a desired position corresponding to the central region of the first member. The reason is considered as follows.

ＩＭＣを生じる反応温度は、通常、第２金属の融点よりも相応に高い。このため、接合工程中の加熱温度が第２金属の融点からＩＭＣの反応温度に至る期間中、第２層（第２金属）は第１層と被覆層との間で液相状態となる。この液相は、第１部材または第２部材の自重や製造装置等により、多かれ少なかれ、加圧された状態となり、接合面に沿った方向に流動し開溝部に充填される。開溝部内の液相は、周囲にある第１金属と反応しつつ、第３層（補強層）に直結された誘導部となる。   The reaction temperature that yields IMC is usually correspondingly higher than the melting point of the second metal. For this reason, the second layer (second metal) is in a liquid phase state between the first layer and the coating layer during the period in which the heating temperature during the joining process reaches the IMC reaction temperature from the melting point of the second metal. This liquid phase is more or less pressurized by the weight of the first member or the second member, the manufacturing apparatus, etc., flows in the direction along the joint surface, and fills the open groove. The liquid phase in the open groove portion reacts with the surrounding first metal, and becomes an induction portion directly connected to the third layer (reinforcing layer).

ちなみに、第１の被覆層（第１金属層）上に第２金属層（第２層に相当）を設ければ、上述した接合材に替えて、第１層（第１金属層）と第３層（第３金属層）からなる接合材を用いることもできる。   By the way, if the second metal layer (corresponding to the second layer) is provided on the first covering layer (first metal layer), the first layer (first metal layer) and the first layer can be replaced with the above-mentioned bonding material. A bonding material composed of three layers (third metal layer) can also be used.

《その他》
（１）本明細書でいう「中央域」とは、第１部材の被接合面の範囲内（内側）で、第１部材が稼働している際に第１部材が最も高温となる点（発熱中心）を含む領域である。従って本明細書でいう中央域は、第１部材の形状に基づいて幾何学的に定まるものではない。但し、通常、半導体素子であれば、被接合面の略中央付近が中央域となる。中央域の外延（外周側との境界）は、敢えていうなら素子周囲に存在するガードリングである。 <Others>
(1) The “central region” as used in the present specification is within the range (inner side) of the surface to be joined of the first member, and the first member becomes the highest temperature when the first member is operating ( This is a region including the heat generation center. Therefore, the central region referred to in this specification is not geometrically determined based on the shape of the first member. However, in general, in the case of a semiconductor element, the central region is in the vicinity of the approximate center of the bonded surface. The extension of the central region (boundary with the outer peripheral side) is a guard ring that exists around the element.

第１部材の温度分布（勾配）は、被接合面に沿う平面的なものに限らず、それに垂直な方向にも存在する立体的なものである。いずれの場合でも、発熱中心付近から離れるほど温度は低下するため、第１部材の中央域（発熱中心付近）で最も大きなパワーサイクルストレスが生じ易い。   The temperature distribution (gradient) of the first member is not limited to a planar one along the surface to be joined, but is a three-dimensional one that exists also in a direction perpendicular thereto. In any case, since the temperature decreases as the distance from the vicinity of the heat generation center increases, the largest power cycle stress is likely to occur in the central region of the first member (near the heat generation center).

（２）本明細書では、説明の便宜上、第１、第２または第３という呼称を用いており、第１部材側に接合部を形成する場合について説明している。第２部材側の接合構造は、第１部材側と同じでも、異なってもよい。 (2) In this specification, for convenience of explanation, the names of first, second, and third are used, and a case where a joint portion is formed on the first member side is described. The joining structure on the second member side may be the same as or different from that on the first member side.

（３）本明細書でいう強度、延性または靱性は、日本工業規格（ＪＩＳ）に準拠して決定される。例えば、延性は応力−ひずみ曲線図における降伏点から破断に至るまでの塑性変形量（ひずみ量）に基づき定める。各特性は室温域におけるものである。 (3) The strength, ductility or toughness referred to in the present specification is determined in accordance with Japanese Industrial Standard (JIS). For example, ductility is determined based on the amount of plastic deformation (strain amount) from the yield point to fracture in the stress-strain curve diagram. Each characteristic is at room temperature.

第３金属は、第１金属よりも高延性であるが、さらに、第１金属よりもヤング率（縦弾性率／室温域）が低いものであると好ましい。通常、低ヤング率な金属は、高延性または高靱性であり補強層（第３層）に相応しい。   The third metal has higher ductility than the first metal, but preferably has a lower Young's modulus (longitudinal elastic modulus / room temperature region) than the first metal. Usually, a metal having a low Young's modulus has high ductility or high toughness and is suitable for a reinforcing layer (third layer).

（４）特に断らない限り本明細書でいう「ｘ〜ｙ」は下限値ｘおよび上限値ｙを含む。本明細書に記載した種々の数値または数値範囲に含まれる任意の数値を新たな下限値または上限値として「ａ〜ｂ」のような範囲を新設し得る。 (4) Unless otherwise specified, “x to y” in this specification includes a lower limit value x and an upper limit value y. A range such as “a to b” can be newly established with any numerical value included in various numerical values or numerical ranges described in the present specification as a new lower limit value or upper limit value.

第１実施例に係るパワーモジュールを示す模式断面図である。It is a schematic cross section which shows the power module which concerns on 1st Example. 第２実施例に係るパワーモジュールを示す模式断面図である。It is a schematic cross section which shows the power module which concerns on 2nd Example. 第３実施例に係るパワーモジュールを示す模式断面図である。It is a schematic cross section which shows the power module which concerns on 3rd Example. 第３実施例に係る接合材の一例を示す模式図である。It is a schematic diagram which shows an example of the joining material which concerns on 3rd Example. 従来のパワーモジュールを示す模式図である。It is a schematic diagram which shows the conventional power module.

本発明の構成要素に、本明細書中から任意に選択した一以上の構成要素を付加し得る。本明細書で説明する内容は、本発明の接合構造体のみならず、その製造方法にも該当し得る。「方法」に関する構成要素は「物」に関する構成要素ともなり得る。   One or more components arbitrarily selected from the present specification may be added to the components of the present invention. The contents described in this specification can be applied not only to the bonded structure of the present invention but also to the manufacturing method thereof. A component related to “method” can also be a component related to “thing”.

《第１金属と第２金属》
第１層（中間層）となる第１金属と、第１金属とＩＭＣ（単相）を生成する第２金属とは種々考えられる。第１金属と第２金属の組合わせは、接合構造体の耐熱温度、接合工程中の加熱温度、熱膨張係数等を考慮して選択される。 << First metal and second metal >>
Various kinds of the first metal that becomes the first layer (intermediate layer) and the second metal that generates IMC (single phase) with the first metal are conceivable. The combination of the first metal and the second metal is selected in consideration of the heat resistance temperature of the bonded structure, the heating temperature during the bonding process, the thermal expansion coefficient, and the like.

第１金属として、Ｎｉ、Ｃｕ，Ｔｉ、Ｍｏ、Ｗ、Ｓｉ、Ｃｒ、Ｍｎ、Ｃｏ、Ｚｒ、Ｎｂ、Ｔａ、Ａｇ、Ａｕ、Ｐｔ、等やそれらの合金がある。第２金属として、Ｓｎ、Ｉｎ、Ｇａ、Ｐｂ、Ｂｉ、Ｚｎ等やそれらの合金がある。好例として、第１金属をＮｉまたはＣｕとし、第２金属をＳｎとするとよい。Ｎｉの融点は約１４５０℃、Ｃｕの融点は約１０８５℃、Ｓｎの融点は約２３０℃である。   Examples of the first metal include Ni, Cu, Ti, Mo, W, Si, Cr, Mn, Co, Zr, Nb, Ta, Ag, Au, Pt, and alloys thereof. Examples of the second metal include Sn, In, Ga, Pb, Bi, Zn, and the like and alloys thereof. As a good example, the first metal may be Ni or Cu, and the second metal may be Sn. The melting point of Ni is about 1450 ° C., the melting point of Cu is about 1085 ° C., and the melting point of Sn is about 230 ° C.

例えば、Ｎｉ層（第１層、中間層、被覆層）とＳｎ層（第２層）を接触させつつ、例えば、約３５０℃で５分間程度加熱すると、ニッケルスズ（ＮｉＳｎ）というＩＭＣ単相が得られる。このＮｉＳｎ（ＩＭＣ）の融点は約７９５℃である。従って、第１金属をＮｉ、第２金属をＳｎとする組合わせは、例えば、ＳｉＣ等からなる次世代半導体素子（第１部材）を用いたパワーモジュール（接合構造体）のように、１５０℃以上の耐熱性が必要とされる一方で、接合工程時の加熱温度を４００℃以下にする必要がある場合に有効である。   For example, when the Ni layer (first layer, intermediate layer, coating layer) and Sn layer (second layer) are in contact with each other and heated at, for example, about 350 ° C. for about 5 minutes, an IMC single phase called nickel tin (NiSn) is formed. can get. The melting point of NiSn (IMC) is about 795 ° C. Therefore, the combination of Ni as the first metal and Sn as the second metal is, for example, 150 ° C. like a power module (joint structure) using a next-generation semiconductor element (first member) made of SiC or the like. While the above heat resistance is required, it is effective when the heating temperature during the bonding process needs to be 400 ° C. or lower.

第１金属／第２金属の他の組合わせとして、Ｃｕ／Ｓｎ、Ａｇ／Ｓｎ、Ｐｔ／Ｓｎ／、Ａｕ／Ｓｎ等がある。なお、接合材側にある中間層（第１層）と、第１部材側にある被覆層とは、異種な第１金属よりも同種の第１金属からなると好ましい。   Other combinations of the first metal / second metal include Cu / Sn, Ag / Sn, Pt / Sn /, and Au / Sn. In addition, it is preferable that the intermediate layer (first layer) on the bonding material side and the coating layer on the first member side are made of the same kind of first metal as compared with the different first metal.

《第３金属》
第３層または補強層となる第３金属も種々考えられる。例えば、高延性や低ヤング率に加えて、熱伝導性や電導性に優れるＡｌ、Ｃｕまたはそれらの合金が第３金属として好ましい。なお、接合構造体の耐久性を確保するため、補強層は中間層や接合層よりも厚い箔状であると好ましい。 《Third metal》
Various third metals serving as the third layer or the reinforcing layer are also conceivable. For example, in addition to high ductility and low Young's modulus, Al, Cu, or an alloy thereof excellent in thermal conductivity and electrical conductivity is preferable as the third metal. In addition, in order to ensure the durability of the bonded structure, the reinforcing layer is preferably a foil shape thicker than the intermediate layer and the bonded layer.

《誘導部》
誘導部は、少なくとも、第１部材の被接合面の少なくとも中央域に対応した位置で、中間層を介さずに補強層に直結してなる。誘導部が接合される補強層の位置も、その中央域であると好ましい。なお、誘導部は、ほぼ同時に生成される接合層と連なっていると好ましい。 <Induction section>
The guiding portion is directly connected to the reinforcing layer without any intermediate layer at least at a position corresponding to at least the central region of the bonded surface of the first member. The position of the reinforcing layer to which the guiding portion is joined is also preferably in the central region. In addition, it is preferable that the induction | guidance | derivation part is connected with the joining layer produced | generated substantially simultaneously.

誘導部は、第１部材の被接合面の少なくとも中央域に対応する領域内に、少なくとも一箇所以上にあれば良い。例えば、複数の孤立した誘導部が点在していてもよいし、線状または環状に連続した誘導部が一以上配置されていてもよいし、それらが組み合わされてもよい。開溝部の配置や形態を調整することにより、誘導部の配置や形態を容易に制御できる。   The induction | guidance | derivation part should just exist in at least 1 place or more in the area | region corresponding to the center area | region at least of the to-be-joined surface of a 1st member. For example, a plurality of isolated guide portions may be scattered, one or more guide portions that are linearly or annularly continuous may be arranged, or a combination of them may be combined. By adjusting the arrangement and form of the open groove part, the arrangement and form of the guide part can be easily controlled.

第１部材の外周囲側またはその被接合面の外周域内（外縁の内側域）で、補強層に連なるＩＭＣからなる外側誘導部または外周誘導部を備えてもよい。これらは、冷熱サイクル下で生じる温度サイクルストレスの緩和やそれに対する耐熱疲労性の向上に有効である（既述した特許文献１参照）。   You may provide the outer side guidance | induction part or outer periphery guidance | induction part which consists of IMC which continues to a reinforcement layer in the outer peripheral side of the 1st member, or the outer peripheral area (inner area of an outer edge) of the to-be-joined surface. These are effective in alleviating temperature cycle stress generated under a cold cycle and improving thermal fatigue resistance thereto (see Patent Document 1 described above).

《接合工程》
接合工程は、第２金属の融点以上で、第１金属と第２金属が反応してＩＭＣを生成する反応温度以上に接合材を加熱する工程ある。第１金属と第２金属の種類、第１部材と第２部材の耐熱性等により反応温度や保持時間は調整される。 << Joining process >>
The bonding step is a step of heating the bonding material to a temperature equal to or higher than the melting point of the second metal and higher than a reaction temperature at which the first metal and the second metal react to generate IMC. The reaction temperature and holding time are adjusted depending on the types of the first metal and the second metal, the heat resistance of the first member and the second member, and the like.

《接合構造体の形態》
本発明の接合構造体には様々な形態が考えられる。接合構造体の好例は、半導体素子を金属電極や基板の金属配線上に接合したパワーモジュールである。半導体素子は、例えば、ＣＴＥが３〜７ｐｐｍ／ＫであるＳｉ、ＳｉＣ、ＧａＮ等からなり、金属電極は、例えば、ＣＴＥが１５〜２５ｐｐｍ／ＫであるＣｕまたはＡｌからなる。 << Form of bonded structure >>
Various forms are conceivable for the bonded structure of the present invention. A good example of the bonded structure is a power module in which a semiconductor element is bonded to a metal electrode or a metal wiring of a substrate. The semiconductor element is made of, for example, Si, SiC, GaN or the like having a CTE of 3 to 7 ppm / K, and the metal electrode is made of, for example, Cu or Al having a CTE of 15 to 25 ppm / K.

本発明の接合構造体の一例であるパワーモジュールについて、具体的な形態を示すことにより、本発明をさらに詳しく説明する。   The present invention will be described in more detail by showing a specific form of the power module which is an example of the bonded structure of the present invention.

次の内容はいずれの形態のパワーモジュールにも共通している。第１部材は、ＳｉＣからなるＩＧＢＴ等のチップ（デバイス、半導体素子）であり、その上下面にＮｉ（第１金）で被覆（メタライズ）された電極面（被覆層）がある。   The following contents are common to all types of power modules. The first member is a chip (device, semiconductor element) such as an IGBT made of SiC, and has an electrode surface (coating layer) coated (metalized) with Ni (first gold) on the upper and lower surfaces thereof.

第２部材は、金属電極を構成するＣｕ板であり、その上面（被接合面）にもＮｉがメタライズされた電極面がある。接合材は、Ａｌ（第３金属）箔からなる第３層を中心に、その両面側にＮｉからなる第１層と、さらにそれらの両面側にＳｎ（第２金属）からなる第２層とが順に形成されている。   The second member is a Cu plate constituting a metal electrode, and an upper surface (surface to be joined) has an electrode surface on which Ni is metallized. The bonding material is centered on a third layer made of Al (third metal) foil, a first layer made of Ni on both sides thereof, and a second layer made of Sn (second metal) on both sides thereof. Are formed in order.

金属電極は、その下面側で、図示しないＤＢＣ（Direct Brazed Copper）基板やＤＢＡ（Direct Brazed Aluminum）基板等の上に実装される。本実施例（各図）に示した上下方向は、鉛直方向に対する上下方向である。但し、それらの方向と、実際にパワーモジュールが製造される時または使用される時の上下方向は異なっていてもよい。   The metal electrode is mounted on a DBC (Direct Brazed Copper) substrate, DBA (Direct Brazed Aluminum) substrate or the like (not shown) on the lower surface side. The vertical direction shown in the present embodiment (each figure) is the vertical direction with respect to the vertical direction. However, those directions may be different from the vertical direction when the power module is actually manufactured or used.

［第１実施例］
（１）パワーモジュールＭ１について、接合前→加熱過程（接合工程）→接合後の各様子を図１に示した。接合前のパワーモジュールＭ１は、ＳｉＣからなるチップ１０（第１部材）とその下面側にあるＮｉが成膜された電極面１１とその上面側にあるＮｉが成膜された電極面１３と電極面１３の外周囲に設けられた絶縁層（ＳｉＮ）１２を有する半導体素子１と、Ｃｕ板２０（第２部材）とその上にＮｉが成膜された電極面２１を有する金属電極２と、接合シート３からなる。 [First embodiment]
(1) About the power module M1, each state before joining → heating process (joining process) → joining is shown in FIG. The power module M1 before bonding includes a chip 10 (first member) made of SiC, an electrode surface 11 on which Ni is formed on the lower surface side thereof, and an electrode surface 13 and electrodes on which Ni is formed on the upper surface side thereof. A semiconductor element 1 having an insulating layer (SiN) 12 provided on the outer periphery of the surface 13, a Cu plate 20 (second member), and a metal electrode 2 having an electrode surface 21 on which Ni is formed; It consists of a joining sheet 3.

接合シート３は、Ａｌ（箔）からなる層３０（第３層）と、その両面側に形成されたＮｉからなる層３１１、３２１（第１層）と、それらの両面側にそれぞれ形成されたＳｎからなる層３１２、３２２（第２層）とを有する。なお、接合シート３の占有面積は、金属電極２よりも小さいが、半導体素子１よりは大きくなっている。   The bonding sheet 3 was formed on a layer 30 (third layer) made of Al (foil), layers 311 and 321 (first layer) made of Ni formed on both sides thereof, and on both sides thereof. And Sn layers 312 and 322 (second layer). The area occupied by the bonding sheet 3 is smaller than that of the metal electrode 2 but larger than that of the semiconductor element 1.

接合シート３は、層３１１、３１２の略中央域に、層３０を底面とする有底円筒状の開溝部３１０を電極面１１側に有する。開溝部３１０は、Ｎｉからなる層３１１とＳｎからなる層３１２とがパターニングされていない領域である。このような開溝部３１０を有する接合シート３は、例えば、開溝部３１０に対応する位置にマスクを配置したＡｌ箔（層３０）の各面上に、ＮｉおよびＳｎを順にスパッタし、Ｎｉ層およびＳｎ層を成膜することにより製作される。   The joining sheet 3 has a bottomed cylindrical open groove 310 with the layer 30 as a bottom surface on the electrode surface 11 side in a substantially central region of the layers 311 and 312. The groove portion 310 is a region where the Ni layer 311 and the Sn layer 312 are not patterned. The bonding sheet 3 having such an open groove 310 is formed by, for example, sequentially sputtering Ni and Sn on each surface of an Al foil (layer 30) having a mask disposed at a position corresponding to the open groove 310. It is manufactured by forming a layer and a Sn layer.

（２）半導体素子１と金属電極２の接合は次のようになされる。上側から下側に向けて順番に、半導体素子１、接合シート３および金属電極２を積層して配置する。半導体素子１と金属電極２で接合シート３を挟持した状態の積層体（挟持体）を、不活性雰囲気（真空雰囲気を含む）や活性雰囲気（水素雰囲気、還元雰囲気等）の加熱炉に入れて、所定の反応温度まで加熱して、一定時間保持する。例えば、挟持する圧力（加圧量）を０．５ＭＰａとして、還元雰囲気の電気炉中で、３５０℃×５分間加熱するとよい。 (2) The semiconductor element 1 and the metal electrode 2 are joined as follows. In order from the upper side to the lower side, the semiconductor element 1, the bonding sheet 3, and the metal electrode 2 are stacked and arranged. The laminated body (clamping body) in which the bonding sheet 3 is sandwiched between the semiconductor element 1 and the metal electrode 2 is put in a heating furnace having an inert atmosphere (including a vacuum atmosphere) or an active atmosphere (hydrogen atmosphere, reducing atmosphere, etc.). Heat to a predetermined reaction temperature and hold for a certain time. For example, the clamping pressure (pressurization amount) may be 0.5 MPa, and heating may be performed at 350 ° C. for 5 minutes in an electric furnace in a reducing atmosphere.

その昇温過程中に、接合シート３の層３１２、３２２が先ず溶融する。これにより、電極面１１と層３１１の間および電極面２１と層３２１の間で、溶融したＳｎが濡れ拡がる。層３１２、３２２の厚さと上記加圧量を調整することにより、Ｓｎの濡れ拡がる領域を制御できる。   During the temperature raising process, the layers 312 and 322 of the bonding sheet 3 are first melted. Thereby, the melted Sn wets and spreads between the electrode surface 11 and the layer 311 and between the electrode surface 21 and the layer 321. By adjusting the thicknesses of the layers 312 and 322 and the amount of pressurization, a region where Sn wets and spreads can be controlled.

電極面１１と層３１１の間の溶融Ｓｎは、開溝部３１０（特に層３１１の窪み）へ充填されると共に、電極面１１の外周囲側へ滲み出して層３１１上に漏出して溜まる。電極面２１と層３２１の間の溶融Ｓｎは、層３２１の外周囲側へ滲み出して、電極面２１上に漏出して溜まる。   The molten Sn between the electrode surface 11 and the layer 311 fills the open groove portion 310 (particularly, the depression of the layer 311) and oozes out to the outer peripheral side of the electrode surface 11 and leaks and accumulates on the layer 311. Molten Sn between the electrode surface 21 and the layer 321 oozes out to the outer peripheral side of the layer 321 and leaks and accumulates on the electrode surface 21.

この状態でさらに昇温されると、層３１２が溶融してできたＳｎは、電極面１１および層３１１と固液相互拡散（ＳＬＩＤ）反応を生じて、ＮｉＳｎ（ＩＭＣ／固相）からなる接合層４１４を形成する。このとき電極面１１と層３１１は、一部が残存して、それぞれ層４１１と層４３１１になる。こうしてチップ１０と層３０は、層４１１と層４３１１（中間層）を介して、接合層４１４で接合された状態となる。   When the temperature is further raised in this state, Sn formed by melting the layer 312 causes a solid-liquid interdiffusion (SLID) reaction with the electrode surface 11 and the layer 311, and is a junction made of NiSn (IMC / solid phase). Layer 414 is formed. At this time, a part of the electrode surface 11 and the layer 311 remains to become a layer 411 and a layer 4311, respectively. In this manner, the chip 10 and the layer 30 are joined by the joining layer 414 via the layer 411 and the layer 4311 (intermediate layer).

このＳＬＩＤ反応の際、層３１２から溶融して開溝部３１０（特に層３１１の窪み）へ充填されたＳｎは、電極面１１と層３１１のＮｉと反応して、層４３１１（中間層）を介さずに、層３０の上面に直結したＩＭＣからなる誘導部４０１４を形成する。   In this SLID reaction, Sn melted from the layer 312 and filled in the groove portion 310 (particularly, the depression of the layer 311) reacts with the Ni of the electrode surface 11 and the layer 311 to form the layer 4311 (intermediate layer). Without passing through, the induction part 4014 which consists of IMC directly connected to the upper surface of the layer 30 is formed.

さらに、チップ１０の外周囲端側へ漏出して層３１１の外周域上に溜まった溶融Ｓｎは、層３１１と反応して、層４３１１（中間層）を介さずに、層３０の上面に直結したＩＭＣからなる外側誘導部４３１４を形成する。   Further, the molten Sn leaking to the outer peripheral end side of the chip 10 and accumulated on the outer peripheral area of the layer 311 reacts with the layer 311 and directly connects to the upper surface of the layer 30 without passing through the layer 4311 (intermediate layer). The outer guiding portion 4314 made of the IMC is formed.

また、層３２２が溶融してできたＳｎは、電極面２１および層３２１と反応して、ＩＭＣからなる接合層４２４を形成する。このとき電極面２１と層３２１は、一部が残存して、それぞれ層４２１と層４３２１になる。こうしてＣｕ板２０と層３０は、層４２１と層４３２１（中間層）を介して、接合層４２４により接合された状態となる。   Further, Sn formed by melting the layer 322 reacts with the electrode surface 21 and the layer 321 to form a bonding layer 424 made of IMC. At this time, a part of the electrode surface 21 and the layer 321 remains to become a layer 421 and a layer 4321, respectively. Thus, the Cu plate 20 and the layer 30 are joined by the joining layer 424 via the layer 421 and the layer 4321 (intermediate layer).

このＳＬＩＤ反応の際、接合シート３の外周囲端側へ漏出して電極面２１の外周域上に溜まった溶融Ｓｎは、電極面２１（Ｎｉ層）と反応して、層４２１（中間層）を介さずに、Ｃｕ板２０の上面に直結したＩＭＣからなる外周誘導部４３２４を形成する。   During this SLID reaction, the molten Sn leaking to the outer peripheral end side of the bonding sheet 3 and accumulated on the outer peripheral area of the electrode surface 21 reacts with the electrode surface 21 (Ni layer) to form a layer 421 (intermediate layer). The outer periphery guiding portion 4324 made of IMC directly connected to the upper surface of the Cu plate 20 is formed without using a gap.

こうして、最上層である層４１１から最下層である層４２１までの各層により構成された接合部４により、チップ１０（第１部材）とＣｕ板２０（第２部材）が接合されたパワーモジュールＭ１が得られる。   In this way, the power module M1 in which the chip 10 (first member) and the Cu plate 20 (second member) are joined by the joint portion 4 constituted by the layers from the uppermost layer 411 to the lowermost layer 421. Is obtained.

ところで、パワーモジュールＭ１は、チップ１０の発熱中心となる（発熱）中央域近傍に、層３０に直結された誘導部４０１４を有する。このためチップ１０やその周辺に作用するパワーサイクルストレスは、誘導部４０１４を通じて層３０へ誘導される。パワーサイクルストレスによりクラックＣが生じるとしても、そのクラックＣは層３０で生じ、接合面に略垂直な方向（上下方向）へ進展するようになる。その結果、チップ１０や接合層４１４等の損傷が回避され、またパワーサイクルストレスの緩和も図られて、パワーモジュールＭ１の信頼性が確保される。   By the way, the power module M1 includes a guide portion 4014 that is directly connected to the layer 30 in the vicinity of the central region (heat generation) that is the heat generation center of the chip 10. Therefore, power cycle stress acting on the chip 10 and its periphery is induced to the layer 30 through the induction unit 4014. Even if the crack C is generated by the power cycle stress, the crack C is generated in the layer 30 and progresses in a direction (vertical direction) substantially perpendicular to the bonding surface. As a result, damage to the chip 10, the bonding layer 414, etc. is avoided, and power cycle stress is mitigated, and the reliability of the power module M1 is ensured.

なお、本実施例のパワーモジュールＭ１は、外側誘導部４３１４、外周誘導部４３２４も備えることにより、冷熱サイクル下で生じる温度サイクルストレスに対しても、緩和性や耐久性に優れたものである。但し、本発明の場合、それら誘導部の存在は必須ではない。   In addition, the power module M1 of the present embodiment also includes the outer guiding portion 4314 and the outer periphery guiding portion 4324, and thus has excellent relaxation properties and durability against temperature cycle stress generated under a cooling / heating cycle. However, in the present invention, the presence of these guiding portions is not essential.

［第２実施例］
パワーモジュールＭ１の一部を変更したパワーモジュールＭ２について、接合前と接合後の各様子を図２に示した。なお、既述した部材または部位については、同符号を付することによりそれらの説明を省略する。この点は後述する他の実施例についても同様である。 [Second Embodiment]
FIG. 2 shows the states of the power module M2 obtained by changing a part of the power module M1 before and after joining. In addition, about the member or site | part mentioned already, those description is abbreviate | omitted by attaching | subjecting a same sign. This also applies to other embodiments described later.

パワーモジュールＭ２の製造に用いる接合シート３は、開溝部３１０に加えて、層３２１、３２２の略中央域に、層３０を底面とする有底円筒状の開溝部３２０を電極面２１側に有する。開溝部３２０も開溝部３１０と同様に製作される。開溝部３１０により形成される誘導部４０１４と同様に、開溝部３２０により誘導部４０２４が形成される。   In the joining sheet 3 used for manufacturing the power module M2, in addition to the groove portion 310, a bottomed cylindrical groove portion 320 having the layer 30 as a bottom surface is provided on the electrode surface 21 side in a substantially central region of the layers 321 and 322. Have. The groove portion 320 is manufactured in the same manner as the groove portion 310. Similarly to the guide portion 4014 formed by the groove portion 310, the guide portion 4024 is formed by the groove portion 320.

誘導部４０２４により、Ｃｕ板２０やその周辺に作用する熱応力も、誘導部４０２４を通じて層３０へ誘導される。その結果、誘導部４０１４と誘導部４０２４が相乗的に作用して、パワーモジュールＭ２の信頼性がより確保される。   The induction part 4024 also induces thermal stress acting on the Cu plate 20 and its periphery to the layer 30 through the induction part 4024. As a result, the induction unit 4014 and the induction unit 4024 act synergistically to further ensure the reliability of the power module M2.

［第３実施例］
パワーモジュールＭ１の一部を変更したパワーモジュールＭ３について、接合前と接合後の各様子を図３に示した。パワーモジュールＭ３の接合シート３は、既述した開溝部３１０を、中央域の中央（発熱中心近傍）に配設する主開溝部３１０ｃと、開溝部３１０ｃから離間してその周囲に配設する複数の副開溝部３１０ｒとに変更したものである。 [Third embodiment]
For the power module M3 in which a part of the power module M1 is changed, each state before and after joining is shown in FIG. The joining sheet 3 of the power module M3 includes the main groove portion 310c disposed at the center of the central area (near the heat generating center) and the groove portion 310c spaced from the groove portion 310c. A plurality of sub-open groove portions 310r are provided.

主開溝部３１０ｃおよび副開溝部３１０ｒの形態、製法は開溝部３１０と同様である。また、開溝部３１０と同様に、主開溝部３１０ｃおよび副開溝部３１０ｒにより、それぞれ主誘導部４０１４ｃおよび副誘導部４０１４ｒが形成される。   The form and manufacturing method of the main groove portion 310c and the sub groove portion 310r are the same as those of the groove portion 310. Similarly to the open groove portion 310, a main guide portion 4014c and a sub guide portion 4014r are formed by the main open portion 310c and the sub open portion 310r, respectively.

本実施例のパワーモジュールＭ３に作用するパワーサイクルストレスは、先ず、主誘導部４０１４ｃから層３０へ導入される。このため、主誘導部４０１４ｃが層３０に直結している付近から最初にクラックが発生し易くなり、これにより主誘導部４０１４ｃ近傍における熱応力が緩和される。   The power cycle stress acting on the power module M3 of the present embodiment is first introduced from the main induction portion 4014c to the layer 30. For this reason, it becomes easy to generate a crack first from the vicinity where the main induction portion 4014c is directly connected to the layer 30, and thereby the thermal stress in the vicinity of the main induction portion 4014c is relieved.

さらにパワーサイクルストレスが引き続きパワーモジュールＭ３へ作用する場合、その熱応力は副誘導部４０１４ｒから層３０へ導入される。その結果、副誘導部４０１４ｒが層３０に直結している付近からもクラックが発生するようになり、副誘導部４０１４ｒ近傍における熱応力も緩和される。このように層３０に発生するクラックが発熱の中心付近からその周辺へ緩やかに拡散していき、パワーモジュールＭ３に作用するパワーサイクルストレスが安定的に緩和され、チップ１０に反り等が生じることが抑止される。   Further, when the power cycle stress continues to act on the power module M3, the thermal stress is introduced into the layer 30 from the auxiliary induction portion 4014r. As a result, cracks are generated from the vicinity where the auxiliary induction portion 4014r is directly connected to the layer 30, and the thermal stress in the vicinity of the auxiliary induction portion 4014r is also alleviated. As described above, the cracks generated in the layer 30 are gradually diffused from the vicinity of the center of heat generation to the periphery thereof, the power cycle stress acting on the power module M3 is stably relieved, and the chip 10 is warped. Deterred.

ちなみに、図３には、接合シート３の副開溝部３１０ｒ（ひいては副誘導部４０１４ｒ）を、主開溝部３１０ｃ（ひいては主誘導部４０１４ｃ）を挟む左右または前後の２箇所に配置する場合を示した。もっとも、その他にも、副開溝部３１０ｒの配置パターンは種々考えられる。例えば、副開溝部３１０ｒは、主開溝部３１０ｃを中央（中心）として放射状に、３箇所以上配置してもよい。さらにいえば、図４に示すように、主開溝部３１０ｃを囲むように副開溝部３１０ｒを配置してもよい。   Incidentally, FIG. 3 shows a case in which the sub-groove portion 310r (and thus the sub guide portion 4014r) of the joining sheet 3 is disposed at two positions on the left and right or front and rear sides of the main groove portion 310c (and thus the main guide portion 4014c). Indicated. However, various other arrangement patterns of the sub-open groove 310r are conceivable. For example, the sub-grooves 310r may be arranged in three or more locations radially with the main groove 310c as the center (center). Furthermore, as shown in FIG. 4, the sub-opening groove 310r may be disposed so as to surround the main opening 310c.

なお、複数の副開溝部３１０ｒを配置する場合、各副開溝部３１０ｒと主開溝部３１０ｃの間隔は一定でなくてもよい。各副開溝部３１０ｒが連続的または近接的であると、層３０に発生するクラックが連結して進展し易くなる。従って、各副開溝部３１０ｒは、孤立して点在状態にあると、クラックは層３０内を緩やかに進展するようになり、パワーモジュールＭ３の信頼性がより高まる。   In addition, when arrange | positioning the some subopening groove part 310r, the space | interval of each subopening part 310r and the main groove part 310c does not need to be constant. When the sub-grooves 310r are continuous or close to each other, cracks generated in the layer 30 are easily connected and progressed. Therefore, if each of the sub-open groove portions 310r is in an isolated and scattered state, the cracks gradually propagate in the layer 30 and the reliability of the power module M3 is further increased.

Ｍ パワーモジュール（接合構造体）
１ 半導体素子
１０ チップ（第１部材）
１１ 電極面（被覆層）
２ 金属電極
２０ Ｃｕ板（第２部材）
３ 接合シート
３１０ 開溝部
４ 接合部
４１４ 接合層
４０１４ 誘導部 M power module (joint structure)
1 semiconductor element 10 chip (first member)
11 Electrode surface (coating layer)
2 Metal electrode 20 Cu plate (second member)
3 Joining sheet 310 Open groove part 4 Joining part 414 Joining layer 4014 Guide part

Claims (6)

第１部材と、
該第１部材と接合され得る第２部材と、
該第１部材と該第２部材を接合する接合部と、
を備える接合構造体であって、
前記接合部は、少なくとも第１部材側に、
前記第１部材の被接合面上に設けられた第１金属からなる被覆層と、
該第１金属と該第１金属よりも低融点な第２金属との金属間化合物からなり該被覆層に接合している接合層と、
該第１金属よりも高延性な第３金属からなる補強層と、
該第１金属からなり該接合層と該補強層とに接合している中間層と、
該金属間化合物からなると共に該第１部材の被接合面の少なくとも中央域で該中間層を介さずに該補強層に直結している誘導部と、
を有する接合構造体。 A first member;
A second member that can be joined to the first member;
A joint for joining the first member and the second member;
A joined structure comprising:
The joint portion is at least on the first member side,
A coating layer made of a first metal provided on the bonded surface of the first member;
A bonding layer made of an intermetallic compound of the first metal and a second metal having a melting point lower than that of the first metal and bonded to the coating layer;
A reinforcing layer made of a third metal having a higher ductility than the first metal;
An intermediate layer made of the first metal and bonded to the bonding layer and the reinforcing layer;
An induction portion made of the intermetallic compound and directly connected to the reinforcing layer without the intermediate layer in at least the central region of the bonded surface of the first member;
A bonded structure having: 前記誘導部は、孤立して複数存在している請求項１に記載の接合構造体。   The joined structure according to claim 1, wherein a plurality of the guiding portions are present in isolation. 前記第１金属は、ＮｉまたはＣｕであり、
前記第２金属は、Ｓｎである請求項１または２に記載の接合構造体。 The first metal is Ni or Cu;
The junction structure according to claim 1, wherein the second metal is Sn. 前記第３金属は、ＡｌまたはＣｕである請求項１〜３のいずれかに記載の接合構造体。   The bonded structure according to claim 1, wherein the third metal is Al or Cu. 前記第１部材は半導体素子であり、
前記第２部材は金属電極である請求項１〜４のいずれかに記載の接合構造体。 The first member is a semiconductor element;
The joined structure according to claim 1, wherein the second member is a metal electrode. 第１部材と第２部材の間で挟持された接合材を加熱して該第１部材と該第２部材を接合する接合工程を備える接合構造体の製造方法であって、
前記第１部材は、被接合面上の少なくとも一部に第１金属からなる被覆層を有し、
前記接合材は、少なくとも該第１部材側に、
該第１金属からなる第１層と、
該第１層の該被覆層側にあり該第１金属よりも低融点な第２金属からなる第２層と、
該第１層の他面側にあり該第１金属よりも高延性な第３金属からなる第３層とを少なくとも有すると共に、
該第１部材の被接合面の少なくとも中央域に対応する位置に、少なくとも該第１層中で該第１金属が形成されていない開溝部を備え、
前記接合工程は、該第２金属の融点以上であって該第２金属と該第１金属が反応して金属間化合物を生成する反応温度以上に該接合材を加熱する工程である接合構造体の製造方法。 A method of manufacturing a joined structure comprising a joining step of heating a joining material sandwiched between a first member and a second member to join the first member and the second member,
The first member has a coating layer made of a first metal on at least a part of the bonded surface;
The bonding material is at least on the first member side,
A first layer comprising the first metal;
A second layer made of a second metal on the side of the coating layer of the first layer and having a lower melting point than the first metal;
And at least a third layer made of a third metal on the other surface side of the first layer and having a higher ductility than the first metal,
A groove corresponding to at least the central region of the surface to be joined of the first member is provided with an open groove portion in which the first metal is not formed in at least the first layer;
The bonding step is a step of heating the bonding material to a temperature equal to or higher than the melting point of the second metal and higher than a reaction temperature at which the second metal and the first metal react to form an intermetallic compound. Manufacturing method.
JP2017155965A 2017-08-10 2017-08-10 Junction structure and method for manufacturing the same Pending JP2019036602A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2017155965A JP2019036602A (en) 2017-08-10 2017-08-10 Junction structure and method for manufacturing the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2017155965A JP2019036602A (en) 2017-08-10 2017-08-10 Junction structure and method for manufacturing the same

Publications (1)

Publication Number Publication Date
JP2019036602A true JP2019036602A (en) 2019-03-07

Family

ID=65637745

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2017155965A Pending JP2019036602A (en) 2017-08-10 2017-08-10 Junction structure and method for manufacturing the same

Country Status (1)

Country Link
JP (1) JP2019036602A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019036601A (en) * 2017-08-10 2019-03-07 株式会社豊田中央研究所 Junction structure and method for manufacturing the same
JP2022103620A (en) * 2020-12-28 2022-07-08 財團法人工業技術研究院 Laminated body and method of manufacturing the same

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017002793A1 (en) * 2015-07-01 2017-01-05 三菱電機株式会社 Semiconductor device and semiconductor device manufacturing method
WO2017086324A1 (en) * 2015-11-16 2017-05-26 株式会社豊田中央研究所 Joining structure and method for manufacturing same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017002793A1 (en) * 2015-07-01 2017-01-05 三菱電機株式会社 Semiconductor device and semiconductor device manufacturing method
WO2017086324A1 (en) * 2015-11-16 2017-05-26 株式会社豊田中央研究所 Joining structure and method for manufacturing same

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019036601A (en) * 2017-08-10 2019-03-07 株式会社豊田中央研究所 Junction structure and method for manufacturing the same
JP2022103620A (en) * 2020-12-28 2022-07-08 財團法人工業技術研究院 Laminated body and method of manufacturing the same
JP7189926B2 (en) 2020-12-28 2022-12-14 財團法人工業技術研究院 LAMINATED PRODUCT AND METHOD FOR MANUFACTURING LAMINATED BODY

Similar Documents

Publication Publication Date Title
JP6451866B2 (en) Junction structure and manufacturing method thereof
EP3208839B1 (en) Substrate with cooler for power modules and method for producing same
US10199237B2 (en) Method for manufacturing bonded body and method for manufacturing power-module substrate
WO2016121159A1 (en) Semiconductor device and method for manufacturing semiconductor device
TW201531188A (en) Jointed body and power module substrate
JP2019036602A (en) Junction structure and method for manufacturing the same
JP2014053384A (en) Semiconductor device and method of manufacturing the same
JP6632589B2 (en) Joint structure and manufacturing method thereof
JP2019036603A (en) Bonding sheet and bonding structure
JP6697422B2 (en) Bonded structure and manufacturing method thereof
JP2019079957A (en) Power module
JP6374240B2 (en) Liquid phase diffusion bonding process for double-sided power modules
JP5808295B2 (en) module
JP5011088B2 (en) Heat dissipation device and power module
JP4703492B2 (en) Lead-free solder material
JP4986843B2 (en) Electronic component package, its lid, lid for the lid, and method for manufacturing the lid
JP5723225B2 (en) Bonding structure
JP2020136336A (en) Junction structure
WO2016031381A1 (en) Semiconductor device
JP7169187B2 (en) power module
JP2004296493A (en) Heat sink, method of manufacturing the same, power module, and method of manufacturing the same
JP2016128184A (en) Solder joint method and power module
JP2020043096A (en) Semiconductor device, bonding sheet, and manufacturing method thereof
JP6991885B2 (en) Semiconductor devices and their manufacturing methods
WO2023248642A1 (en) Laminated bonding material, semiconductor package, and power module

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20191202

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20201022

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20201110

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20210511