JPH0794532A - Button electrode type semiconductor device - Google Patents

Abstract

PURPOSE:To provide a button electrode type semiconductor device wherein a stable soldering quality is obtained in its assembling process and a high reliability is obtained in its operational aspect. CONSTITUTION:In a button electrode type semiconductor device, two button type electrodes 2 are so superimposed on both sides of a semiconductor chip 1 having both its surfaces as principal surfaces that the semiconductor chip 1 is interposed between the electrodes 2 and its respective principal surfaces are soldered to the electrodes 2 and further the peripheries of the semiconductor chip 1, the solder and the electrodes 2 are sealed with a resin. In this button electrode type semiconductor device, the button type electrode 2 is stamped while a flat copper plate is used as its raw material. Thereby, the opposite end surface of the electrode 2 to the semiconductor chip 1 is made flat, and the peripheral edge of the stepped part of the electrode 2 is made sharp. As a result, a normal solder fillet is formed between the electrode 2 and the semiconductor chip 1, and a stable soldering quality is obtained.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、ダイオード，サージア
ブソーバなどを対象としたボタン電極形半導体装置に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a button electrode type semiconductor device intended for diodes, surge absorbers and the like.

【０００２】[0002]

【従来の技術】まず、頭記ボタン電極形半導体装置の従
来における組立構造，およびそのボタン形電極の製造方
法を図３（ａ),（ｂ）により説明する。（ａ）図におい
て、１は両面を主面とする半導体チップ、２は半導体チ
ップ１を挟んでその両側に重ね合わせたボタン形電極、
３は半導体チップ１の主面とボタン形電極２との間を接
合した半田、４は封止樹脂である。ここで、ボタン形電
極２は直径４mm，高さ３mm程度の小サイズな電極であっ
て、その形状は図示のように２段重ねの段付き部が形成
されており、半田付けした際に半導体チップ１と段付き
部との間に半田フィレットを形成するようにしている。2. Description of the Related Art First, a conventional assembly structure of a button electrode type semiconductor device and a method of manufacturing the button type electrode will be described with reference to FIGS. In FIG. 1 (a), 1 is a semiconductor chip whose main surface is on both sides, 2 is a button-shaped electrode which is sandwiched on both sides of the semiconductor chip 1 and overlapped with each other,
Reference numeral 3 is solder that joins the main surface of the semiconductor chip 1 and the button-shaped electrode 2 and reference numeral 4 is a sealing resin. Here, the button-shaped electrode 2 is a small-sized electrode having a diameter of 4 mm and a height of 3 mm, and the shape thereof has a stepped portion formed by stacking two steps as shown in the drawing. A solder fillet is formed between the chip 1 and the stepped portion.

【０００３】なお、ボタン形電極２にはあらかじめＮｉ
メッキが施されており、半田付け作業は、主面に予備半
田を施した半導体チップ１を一対のボタン形電極２の間
に挟み込み、押え治具でボタン形電極２を加圧保持しな
がらリフロー半田付けを行うようにしている。また、従
来ではこのボタン形電極２を鍛造品として製作してい
る。すなわち、（ｂ）図で示すようにボタン形電極の形
状に合わせて作られたダイス５，ポンチ６からなる鍛造
用打型に銅材のタブレット７を挿入し、ポンチ６をプレ
ス操作してボタン形電極２を鍛造する。The button-shaped electrode 2 is preliminarily made of Ni.
In the soldering work, which is plated, the main surface is pre-soldered, and the semiconductor chip 1 is sandwiched between a pair of button-shaped electrodes 2 and reflowed while the button-shaped electrodes 2 are pressed and held by a holding jig. I try to solder. Further, conventionally, the button type electrode 2 is manufactured as a forged product. That is, as shown in FIG. 2 (b), a copper tablet 7 is inserted into a forging die made up of a die 5 and a punch 6 which are made to match the shape of a button-shaped electrode, and the punch 6 is pressed to operate the button. The shaped electrode 2 is forged.

【０００４】[0004]

【発明が解決しようとする課題】ところで、前記のよう
に鍛造品とし作られたボタン形電極は、図１（ａ）で表
すように端面が完全に平坦化されずに凸面状を呈し、か
つ段付き部の周縁コーナー加工面にダレが発生して丸み
を帯びたエッジを呈した形状になる。このために、半導
体チップ１にボタン形電極２を重ね合わせた際に電極２
の端面全域が半導体チップ１の主面に密着せず、かつこ
の状態で半田付けを行うと、溶融半田が段付き部の周縁
で止まらず、段付き部の周縁エッジが丸みを帯びていて
周面と連続的に連なっているために、半田の一部はエッ
ジを越えて外周側に流れ出して半田フィレットの形が崩
れてしまう。この結果、半田付けの際に溶融半田の表面
張力による半導体チップのセルフアライメント機能が十
分に働かず、電極の間に挟まれた半導体チップ１が図示
のようにボタン形電極２の中心からずれた位置に変位
し、極端な場合には半導体チップ１の周縁が封止樹脂４
から外側に露出したりして、これが欠陥となって半導体
装置の動作特性に悪影響を及ぼす。また、前記のように
半導体チップ１に対面するボタン片電極２の端面が凸面
を呈していると実使用時に半導体チップに流れる電流分
布が均一にならず、特にサージが侵入した際には電流が
局部的に集中してサージ耐量が低下するなどの不具合を
引き起こす。By the way, the button-shaped electrode manufactured as a forged product as described above has a convex shape, as shown in FIG. 1 (a), whose end faces are not completely flattened, and The peripheral edge corner processed surface of the stepped portion is sagged to have a rounded edge. For this reason, when the button-shaped electrode 2 is superposed on the semiconductor chip 1, the electrode 2
If the entire end surface of the stepped portion does not adhere to the main surface of the semiconductor chip 1 and soldering is performed in this state, the molten solder does not stop at the peripheral edge of the stepped portion, and the peripheral edge of the stepped portion is rounded. Since it is continuously connected to the surface, a part of the solder flows over the edge to the outer peripheral side, and the shape of the solder fillet collapses. As a result, the self-alignment function of the semiconductor chip due to the surface tension of the molten solder does not work sufficiently during soldering, and the semiconductor chip 1 sandwiched between the electrodes is displaced from the center of the button electrode 2 as shown in the figure. Is displaced to the position, and in the extreme case, the peripheral edge of the semiconductor chip 1 is the sealing resin 4
From the outside to the outside, which becomes a defect and adversely affects the operating characteristics of the semiconductor device. Further, as described above, when the end surface of the button piece electrode 2 facing the semiconductor chip 1 has a convex surface, the distribution of the current flowing through the semiconductor chip is not uniform during actual use, and in particular, when the surge enters, the current is This causes problems such as local concentration and a drop in surge resistance.

【０００５】本発明は上記の点にかんがみなされたもの
であり、その目的は前記課題を解決して組立工程での安
定した半田付け性，並びに動作面での高信頼性が得られ
るボタン電極形半導体装置を提供することにある。The present invention has been made in view of the above points, and an object thereof is to solve the above problems and to provide stable solderability in the assembly process and high reliability in operation. It is to provide a semiconductor device.

【０００６】[0006]

【課題を解決するための手段】上記目的を達成するため
に、本発明は、半導体チップと向かい合うボタン形電極
の端面を平坦面となし、かつ電極の段付き部周縁を尖鋭
なエッジに形成するものとする。そして、このボタン形
電極を、銅の平板を素材としてプレス抜き加工法で製作
することにより、製品精度の高い前記形状のボタン形電
極が得られる。In order to achieve the above object, the present invention forms the end surface of a button-shaped electrode facing a semiconductor chip as a flat surface and forms the stepped portion peripheral edge of the electrode into a sharp edge. I shall. Then, this button-shaped electrode is manufactured by a press punching method using a copper flat plate as a material, so that the button-shaped electrode having the above-described shape with high product accuracy can be obtained.

【０００７】[0007]

【作用】上記のようにプレス抜き加工法により製作され
たボタン形電極は製品精度が良く、鍛造製品で見られる
ような加工面のダレの発生が殆どなく、かつ電極の端面
は素材である銅製平板の平坦な板面をそのまま利用する
ので、電極端面が凸面状を呈するようなことがない。し
たがって、半導体チップの主面にボタン形電極を重ね合
わせた状態では電極端面の全域が半導体チップの主面に
均一に密着するようになり、かつ半田付けの際には溶融
半田が表面張力により段付き部の尖鋭なエッジより内側
に保持されて段付き部のエッジを乗り越えて外周側に流
れ出すことがなく、半導体チップとの間に正常な形の半
田フィレットが形成されるようになる。[Function] The button-shaped electrode manufactured by the press punching method as described above has good product accuracy, hardly causes sagging of the processed surface as seen in a forged product, and the end surface of the electrode is made of a copper material. Since the flat plate surface of the flat plate is used as it is, the electrode end surface does not have a convex shape. Therefore, in the state where the button-shaped electrode is superposed on the main surface of the semiconductor chip, the entire area of the electrode end surface is brought into close contact with the main surface of the semiconductor chip evenly. The solder fillet having a normal shape is formed between the semiconductor chip and the solder fillet, because the solder fillet is held inside the sharp edge of the attachment portion and does not flow over the edge of the step portion and flows out to the outer peripheral side.

【０００８】これにより、半田付け工程での半田付け性
が安定して製品の良品率が高まるとともに、半導体装置
の動作特性面での信頼性も向上する。As a result, the solderability in the soldering process is stabilized, the yield rate of the products is increased, and the reliability of the operation characteristics of the semiconductor device is also improved.

【０００９】[0009]

【実施例】以下、本発明の実施例を図１，図２に基づい
て説明する。なお、実施例の図中で図３に対応する同一
部材には同じ符号が付してある。すなわち、本発明では
半導体装置に組み込むボタン形電極２として、図２で示
すように銅の平板８の素材をダイス９，ポンチ１０を組
合わせた金型によりプレス打ち抜き加工して製作したも
のが採用される。このようにプレス加工法で作られたボ
タン形電極２は、鍛造加工法で見られるような加工面の
ダレも殆ど発生せず、加工形状についても高い製品精度
が得られる。また、実際にプレス加工されたボタン形電
極について、その外観を検査した結果でも、図示のよう
に半導体チップ１の主面に対向するボタン形電極２の端
面全域が平坦面（銅製平板の板面がそのまま電極端面と
なる）を呈し、かつ段付き部の周縁が尖鋭なエッジを形
成するように加工されているが確認されている。Embodiments of the present invention will be described below with reference to FIGS. In the drawings of the embodiments, the same members corresponding to FIG. 3 are designated by the same reference numerals. That is, in the present invention, as the button-shaped electrode 2 incorporated in the semiconductor device, as shown in FIG. 2, the one manufactured by press punching the material of the copper flat plate 8 with the die having the combination of the die 9 and the punch 10 is adopted. To be done. In this way, the button-shaped electrode 2 formed by the press working method hardly causes sagging of the machined surface as seen in the forging method, and high product accuracy can be obtained in the machined shape. Further, as a result of inspecting the appearance of the actually pressed button-shaped electrode, as shown in the figure, the entire end surface of the button-shaped electrode 2 facing the main surface of the semiconductor chip 1 is a flat surface (a plate surface of a copper flat plate). Has been processed so as to form sharp edges on the periphery of the stepped portion.

【００１０】そして、前記のようにプレス打ち抜き加工
法により製作したボタン形電極２を用いて半導体チップ
１との間で半田付けを行うと、図示のようにチップの主
面と電極の段付き部との間で半田が均一に流動して正常
な形の半田フィレットを形成する。これにより、半導体
チップが定位置からずれ動くこともなく、かつボイドな
どの内部欠陥も見られずに良好な半田付けの接合状態が
が得られる。このことは製品の検査結果からも確認され
ている。When the button-shaped electrode 2 manufactured by the press punching method as described above is used for soldering with the semiconductor chip 1, as shown in the drawing, the main surface of the chip and the stepped portion of the electrode are formed. The solder uniformly flows between and forms a normal shape solder fillet. As a result, the semiconductor chip does not move from the fixed position, and an internal defect such as a void is not seen, and a good soldering state can be obtained. This is confirmed by the inspection result of the product.

【００１１】[0011]

【発明の効果】以上述べたように、本発明によれば、半
田付け工程が安定して製品の良品率が向上し、併せて動
作特性面でも高い信頼製の得られるボタン電極形半導体
装置を製作，提供することができる。As described above, according to the present invention, it is possible to provide a button electrode type semiconductor device in which the soldering process is stable, the non-defective rate of the product is improved, and at the same time, the operating characteristics are high and reliable. Can be manufactured and provided.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の実施例によるボタン電極形半導体装置
の組立構造断面図FIG. 1 is a sectional view of an assembly structure of a button electrode type semiconductor device according to an embodiment of the present invention.

【図２】図１におけるボタン形電極のプレス打ち抜き加
工法の説明図FIG. 2 is an explanatory view of a press punching method for the button type electrode in FIG.

【図３】従来におけるボタン電極形半導体装置の説明図
であり、（ａ）は組立構造断面図、（ｂ）はボタン形電
極の鍛造加工法の説明図3A and 3B are explanatory views of a conventional button electrode type semiconductor device, FIG. 3A is a sectional view of an assembly structure, and FIG. 3B is an explanatory view of a button electrode forging method.

【符号の説明】[Explanation of symbols]

１ 半導体チップ ２ ボタン形電極 ３ 半田 ４ 封止樹脂 ８ 銅製平板（素材） ９ プレス打ち抜き型のダイス １０ ポンチ 1 Semiconductor Chip 2 Button Electrode 3 Solder 4 Sealing Resin 8 Copper Flat Plate (Material) 9 Press-Punching Die 10 Punch

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】両面を主面とする半導体チップを挟んでそ
の両側に重ね合わせたボタン形電極と半導体チップの各
主面との間を半田付けし、その周囲を樹脂封止してなる
ボタン電極形半導体装置において、半導体チップと向か
い合うボタン形電極の端面を平坦面となし、かつ電極の
段付き部周縁を尖鋭なエッジに形成したことを特徴とす
るボタン電極形半導体装置。1. A button formed by soldering between a button-shaped electrode, which is sandwiched on both sides of a semiconductor chip whose main surface is a main surface, and is stacked on both sides of the semiconductor chip, and each main surface of the semiconductor chip, and whose periphery is sealed with a resin. In the electrode type semiconductor device, a button electrode type semiconductor device is characterized in that an end surface of a button type electrode facing a semiconductor chip is a flat surface and a stepped portion peripheral edge of the electrode is formed into a sharp edge. 【請求項２】請求項１記載の半導体装置において、ボタ
ン形電極が、銅の平板を素材としてプレス抜き加工によ
り製作されたものであることを特徴とするボタン電極形
半導体装置。2. The button electrode type semiconductor device according to claim 1, wherein the button type electrode is manufactured by press punching using a copper flat plate as a material.