JP2005251771A - Semiconductor device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable semiconductor device where short circuit between electrodes due to protrusion of bonding material to the side of a semiconductor element does not exist in bonding of the electrodes of the semiconductor element such as a diode chip and the like and leads, and to provide its manufacturing method. <P>SOLUTION: The electrodes 2 and 4 are provided on both faces of the semiconductor element 1. Woven fabric-like or non-woven fabric-like metal conductors 601 and 602 formed of metal wires or metal fibers are inserted between the electrodes and sheet-like leads 3 and 5 confronted with the electrodes through a member with which the bonding material is filled. The bonding material is heated and melted. Thus, the electrodes of the semiconductor element and the leads are connected, or it is bonded with the electrodes of the semiconductor element with the planar metal conductors themselves as the leads. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof, for example, a semiconductor device with leads in which electrodes on both sides of a semiconductor element chip facing each other and leads are connected, and a manufacturing method thereof.

  In recent years, various devices have been made thinner, and attention has been focused on semiconductor devices suitable for thin packaging. For example, a diode used for a bypass diode mounted on a thin plate-shaped solar cell in a solar panel or the like is a solar cell module when a conventional resin-encapsulated diode is used because the solar cell is thin. Therefore, a thin leaded diode suitable for thin mounting is used.

  FIG. 7 is a sectional view of a diode showing an example of a thin leaded diode.

  In FIG. 7, 1 is a diode chip, 2 is a cathode electrode provided on one surface of the diode chip 1, 3 is a lead provided opposite to the cathode electrode 2, and 4 is provided on the other surface of the diode chip 1. The anode electrodes 5 and 5 are leads provided to face the anode electrode 4. Conventionally, the diode chip 1 is sandwiched between thin plate-like leads 3 and 5 facing the electrodes 2 and 4 provided on both surfaces thereof via a bonding material such as solders 701 and 702, and thereafter a bonding material such as solder is applied. A structure in which the joint between the electrode 2 of the diode chip 1 and the lead 3 and the joint between the electrode 4 and the lead 5 of the diode chip 1 are formed by heating and melting is common. As for the manufacturing method of these diodes, when the bonding material is solder, the solder is generally supplied by screen printing. First, the solder paste is applied to a predetermined portion of the lead, and then the solder paste of the lead is applied. A diode chip is mounted on the surface. Then, a method is generally used in which the electrodes and leads of the diode chip are joined and the leads and the diode chip electrodes are connected by sandwiching them and heating the solder in a solder reflow process.

  As a method for supplying the bonding material, in addition to a method for supplying the solder paste by printing or the like, there are a method such as plating or vapor deposition, and a method for arranging the solder foil piece at a predetermined position. As a method for heating the solder, reflow heating is generally used, but there is also a method of heating with a plate having a built-in heater.

  In these semiconductor devices such as diodes, in order to reduce the thermal resistance and improve the temperature characteristics, the diode chip joined to the lead is often processed thinly. Therefore, when these thin diode chips are joined to the thin plate-shaped leads with solder, if a large amount of solder is supplied, the solder protrudes from the joint surface to the outer peripheral surface of the chip as shown in FIG. A fatal defect occurs in which the lead contacts and the leads short. Also, if the amount of solder is small, the solder does not spread over the entire joint surface, the thermal resistance of the joint becomes large, the heat dissipation becomes poor due to heat generation, and the diode does not show normal characteristics.

  In particular, when a side surface is not coated with an insulating coating such as a planar type diode chip, it is essential to manage the supply of a strict solder amount in order to prevent a short circuit between electrodes.

  Further, as in the case of a mesa type diode chip as disclosed in Patent Document 1, in the case of a structure in which the side surface of the chip is etched and the side surface of the chip is coated with glass passivation or the like, the solder protrudes from the side surface. However, since insulation is achieved by the coating process, the occurrence of short-circuit between electrodes is less than that of the planar type. However, if the amount of solder is not strictly controlled, there is a sufficient possibility that short-circuit between electrodes due to solder protrusion will occur frequently.

Japanese Patent Laid-Open No. 2002-158324

  The present invention has been made in view of the above-described point, and a highly reliable semiconductor in which there is no short-circuit between electrodes due to protrusion of a bonding material to a side surface of a semiconductor element in bonding between an electrode of a semiconductor element such as a diode chip and a lead. An apparatus and a method for manufacturing the same are provided.

  In order to solve the above problems, the invention of claim 1 has a first electrode on one surface of a semiconductor element, a second electrode on the other surface of the semiconductor element, and the first electrode. In the semiconductor device in which the first lead facing the first electrode is bonded with a bonding material, and the second electrode is bonded with the second lead facing the second electrode with a bonding material, At least one of the gap between the first electrode and the first lead and the gap between the second electrode and the second lead has a woven or non-woven shape made of a metal wire or metal fiber. A member in which a metal conductor is filled with a bonding material, or a member in which a thin plate-like metal conductor with a recess or groove formed on the surface is filled with a bonding material, or a sheet-like shape in which the surface and inside are processed to have a gap portion Providing a member filled with a bonding material in a metal conductor, Characterized in that to sandwich the semiconductor device in the as one of the leading second lead and bonding the between the lead and the electrode of the semiconductor element.

  In order to solve the above-mentioned problem, the invention of claim 2 has a first electrode on one surface of a semiconductor element, a second electrode on the other surface of the semiconductor element, and the first electrode. In the semiconductor device in which the first lead facing the first electrode is bonded with a bonding material, and the second electrode is bonded with the second lead facing the second electrode with a bonding material, At least one of the first lead and the second lead is a member in which a woven or non-woven metal conductor made of a metal wire or metal fiber is filled with a bonding material, or a recess or groove is formed on the surface. The first lead is composed of a member obtained by filling a thin plate-like metal conductor with a bonding material, or a member obtained by filling a thin plate-shaped metal conductor having a void portion on the surface and inside with a bonding material. And the second lead Characterized in that bonding the between the lead and the electrode of the semiconductor element is.

  In order to solve the above problem, the invention of claim 3 is characterized in that, in the invention of claim 1 or 2, the metal conductor has good wettability with the bonding material when heated.

  In order to solve the above-mentioned problems, the invention of claim 4 is characterized in that, in the invention of any one of claims 1 to 3, the bonding material is solder.

  In order to solve the above problem, the invention of claim 5 has a first electrode on one surface of a semiconductor element, a second electrode on the other surface of the semiconductor element, and the first electrode. Is bonded to the first lead facing the first electrode with a bonding material, and the second electrode is bonded to the second lead facing the second electrode with a bonding material. In the method, at least one of the gap between the first electrode and the first lead and the gap between the second electrode and the second lead has a woven cloth shape made of a metal wire or metal fiber. Or a member in which a non-woven metal conductor is filled with a bonding material, or a member in which a thin plate-like metal conductor whose surface is hollowed or grooved is filled with a bonding material, or a process having voids on the surface and inside. A sheet metal conductor filled with a bonding material And kicking step, a step of sandwiching said semiconductor device in said first lead the second lead, and having a step of heating and melting the joining material.

  In order to solve the above-described problem, the invention of claim 6 has a first electrode on one surface of a semiconductor element, a second electrode on the other surface of the semiconductor element, and the first electrode. Is bonded to the first lead facing the first electrode with a bonding material, and the second electrode is bonded to the second lead facing the second electrode with a bonding material. In the method, at least one of the first lead and the second lead is a member in which a bonding material is filled in a woven or non-woven metal conductor whose bonding material is made of a metal wire or metal fiber, or a surface A process comprising a member obtained by filling a thin plate-like metal conductor with a recess or groove processed with a bonding material, or a member obtained by filling a thin plate-shaped metal conductor having a void portion on the surface and inside with a bonding material. And the first lead and the second lead A step of clamping the semiconductor device in, characterized by having a step of heating and melting the joining material.

  According to the present invention, a woven or non-woven metal conductor made of a metal wire or a metal fiber, or a thin plate-like metal conductor whose surface is recessed or grooved in electrode bonding between an electrode and a lead of a semiconductor element. Or, the surface of the metal conductor and the surface of the void portion of these metal conductors get wet with the bonding material by heating and melting the bonding material filled in the thin plate-shaped metal conductor which has been processed to have voids on the surface and inside. As a result, the bonding material is impregnated in the gap between these members, so that excess bonding material is absorbed in the electrode bonding between the electrode of the semiconductor element and the lead, and the protrusion of the bonding material to the side surface of the semiconductor element is eliminated. It is possible to prevent a short circuit between both electrodes of the element. In addition, the semiconductor element is sandwiched between the first lead and the second lead and heated and melted to pressurize the surface of the electrode bonding portion, so that the thickness of the bonding layer can be made thin and uniform, thereby improving heat dissipation. Thereby, a highly reliable semiconductor device is realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments.

(First embodiment)
FIG. 1 is a sectional view showing a main part of a semiconductor device according to the first embodiment of the present invention. In FIG. 1, 1 is a diode chip, 2 is a first electrode (cathode electrode) provided on one surface of the diode chip 1, 3 is a first lead facing the first electrode 2, and 4 is a first lead. The second electrode (anode electrode) 5 provided on the opposite surface of the electrode 2 is a second lead facing the second electrode 4. Reference numerals 601 and 602 denote metal mesh members (metal conductors) filled with solder 701 and 702 in advance.

  In the present embodiment, in the above configuration, the first lead 3 and the second lead 5 are both made of copper foil, and are formed in the gap between the first lead 3 facing the first electrode 2 of the diode chip 1. A metal mesh member 601 is arranged, and a metal mesh member 602 is arranged in the gap between the second leads 5 facing the second electrode 4. These metal net-like members 601 and 602 have a sheet-like structure in which solder-plated copper fine wires are knitted in a lattice shape, and have a uniform thickness, and a solder paste is pre-filled in a gap between the copper fine wires. It is a member, and the wettability with solder is improved by heating and melting.

  As a method of filling the metal mesh member with the solder in advance, the solder paste may be filled by printing or the like, or may be preheated and filled in a state where the solder foil piece is arranged before the lead is connected. . If there is no problem in the solder absorption effect and the inter-electrode short-circuit preventing effect in the method for supplying a bonding material such as solder, there is also a method for supplying a bonding material in advance to the electrodes or leads of the semiconductor element as in the prior art.

  In the manufacturing process of the above configuration, first, the solder is heated by sandwiching the diode chip 1 between the first lead 3 and the second lead 5 via the metal mesh members 601 and 602 filled with the solder paste. After melting, the first electrode 2 and the first lead 3 are joined via the metal mesh member 601, and the second electrode 4 and the second lead 5 are joined via the metal mesh member 602. At this time, the surfaces of the fine metal wires constituting the metal mesh members 601 and 602 are solder-plated and have good wettability with the solder. Therefore, excess solder is absorbed in the gaps between the fine metal wires, and the solder Does not protrude to the outer peripheral side surface of the chip. Therefore, with the above configuration, a short circuit between the first electrode 2 and the second electrode 4 can be prevented.

  Also, the surface pressure is applied by sandwiching the diode chip between the first lead 3 and the second lead 5 through the metal mesh members 601 and 602 having a uniform thickness, and heating and melting the solder chip. Can be formed thinly and uniformly, improving heat dissipation.

  The metal mesh member is a sheet-like structure in which fine metal wires are knitted into each other by various knitting methods, and the gap between the fine metal wires includes the knitting method, fine metal wire diameter, mesh (interval). ) Can be set by changing.

  As the material of the metal thin wire, there are gold, silver, brass, aluminum, etc. that are soft and easy to process and have low heat resistance and electrical resistance. If the surface of the metal thin wire has good wettability with the solder, electroplating, The member of the structure which gave surface treatments, such as gold | metal | money, silver, tin, nickel, by methods, such as metal vapor deposition, may be sufficient.

  In this embodiment, a metal mesh member is used as a constituent member provided between the lead and the electrode. However, a material or surface treatment that has a void in the member and has good wettability with a joining member such as solder by heat melting. As long as the bonding material is impregnated and absorbed in the gaps, the woven or non-woven metal conductor formed by weaving or entwining metal fibers in the form of a net, or a thin plate with dents or grooves on the surface It may be a member in the form of a planar metal conductor, or a planar metal conductor such as punched metal or expanded metal that has been processed to have a void on the surface and inside.

  The punching metal is a structure in a form in which a thin plate metal is subjected to a plurality of holes. The hole shape, hole size, hole position, hole interval, and hole arrangement can be designed relatively freely by pressing or etching.

  Moreover, said expanded metal is a structure of the form which gave the cut | interruption process match | combined with the mesh shape on the thin plate-shaped metal, and formed the stretched mesh. Like the punching metal, it is an integral structure.

  In addition, when punching metal is applied as a constituent member (metal conductor) provided between the lead and the electrode, the punching metal is similar to a lead made of a conventional metal foil except for drilling, so that the conventional method including the lead attachment process is used. There is an advantage that equivalent handling is possible. In addition, punching metal has a high degree of freedom in processing, such as being able to change and process the hole shape, hole size, hole position, hole interval, hole arrangement, etc. relatively easily, and ensure wettability with bonding materials such as solder. Can be dealt with by partial plating, hole arrangement, etc., so that the optimization of the bonding material absorption effect in consideration of the heating process such as the reflow process can be realized relatively easily.

  In addition, regarding the components provided between the lead and the electrode, if there is no problem in the flatness and the absorption effect of the bonding material such as solder, the expanded metal or the punching metal is more likely to fray the fine metal wire due to the shape processing of the member than the metal mesh member. There is no need to worry about this, and there are advantages when processing and handling parts.

  In the present embodiment, a metal net-like member filled with solder is provided in both the gap between the first electrode 2 and the first lead 3 and the gap between the second electrode 4 and the second lead 5. However, it may be provided only in one gap as long as the effect of preventing a short circuit between the electrodes due to the protrusion of the bonding material to the side surface of the semiconductor element can be obtained.

(Second Embodiment)
FIG. 2 is a cross-sectional view showing the main part of a semiconductor device according to the second embodiment of the present invention.

  The present embodiment is different from the first embodiment in that the second lead itself is constituted by a wire mesh member 602 and there is no second lead member made of copper foil. According to this structure, since there are few structural members, it can comprise cheaply.

  In the present embodiment, a metal mesh member 601 filled with solder 701 is disposed in the gap between the first electrode 2 and the first lead 3 facing the first electrode 2. On the other hand, a second lead 5 made of a wire mesh member 602 is arranged opposite to the second electrode 4 (anode electrode). A region facing the second electrode 4 in the wire mesh member 602 is filled with solder 702 in advance as in the first embodiment. Therefore, by sandwiching the diode chip 1 between the first lead 3 and the second lead 5 and heating, the first electrode 2 and the first lead 3 with no protrusion of solder as in the first embodiment. Bonding and solder bonding between the second electrode 4 and the second lead 5 are possible.

  In the above configuration, since the second lead 5 has a structure in which a fine metal wire filled with solder is woven, the second lead 5 is more flexible than the conventional metal foil lead and is suitable for bending. It is suitable for (mounting on a thin plate-like element electrode).

  In the above configuration, the metal mesh member 602 may have a structure in which solder is filled in at least a region corresponding to the second electrode 4 and absorbs the solder protruding from the side surface of the diode chip 1. The lead 5 may be a member filled with solder.

  Furthermore, in the manufacturing method having the above configuration, if there is no problem in heat dissipation, there is also a method in which solder bonding is performed only by passing through a reflow process without sandwiching the leads and applying pressure to the solder joint. .

  In the present embodiment, the metal mesh member 601 filled with solder is provided in the gap between the first electrode 2 and the first lead 3, and the metal mesh member 602 filled with solder is used as the second lead 5. Although it is used, both the first lead and the second lead may be constituted by a metal mesh member filled with solder. If the effect of preventing the short circuit between the electrodes due to the protrusion of the bonding material to the side surface of the semiconductor element can be obtained, one of the first lead and the second lead is constituted by a metal mesh member filled with solder, and the other is conventional. It can also be set as the following.

  Further, the present embodiment is an embodiment to which a metal mesh member is applied as in the first embodiment, but if there is a solder absorption effect equivalent to this embodiment, punching metal other than the metal mesh member or A member in the form of expanded metal may be used.

(Third embodiment)
FIG. 4 is a cross-sectional view showing a main part of a semiconductor device according to the third embodiment of the present invention, and FIG. 5 is a top view of a metal net member 602 according to the third embodiment of the present invention. FIG. 6 is an explanatory diagram of a method for manufacturing a semiconductor device according to the third embodiment of the present invention.

  In the present embodiment, the metal mesh member 602 disposed in the gap between the second electrode 4 of the diode chip 1 and the second lead 5 facing the diode chip 1 is not filled with solder in advance, and the shape of the metal mesh member 602 5 has a frame shape having an opening (hollow part) 602a at the center and corresponding to the outer periphery of the chip, as shown in FIG. 5, and the first lead 3 facing the first electrode 2 in the first embodiment. The difference from the first embodiment is that the metal mesh member 601 provided in the gap is not provided. According to such a configuration, it is possible to perform solder bonding between the second electrode 4 and the second lead 5 with no protrusion of solder in a configuration close to conventional electrode bonding and a bonding process similar to the conventional one.

  In the manufacturing process of the above configuration, as shown in FIG. 6, for the electrode bonding of the first electrode 2, the solder 701 is supplied to the first lead 3 as in the conventional electrode bonding process. As for the electrode bonding of the second electrode 4, the solder 702 is supplied to the second lead 5, and the gap between the second electrode 4 and the second lead 5 facing the second electrode 5 is as shown in FIG. A metal net member 602 provided with a hollow portion 602a corresponding to a portion where the solder 702 is supplied to the second lead 5 is disposed. The diode chip 1 is sandwiched between the first lead 3 and the second lead 5 and reflow heating is performed, so that the first electrode 4 (anode electrode) and the second lead 5 are soldered together with the first lead 3. As in the embodiment, since excess solder is absorbed in the gaps of the metal mesh member 602, it is possible to prevent the solder from protruding. Therefore, even if there is some protrusion on the cathode side, it is possible to prevent the occurrence of a short circuit between the electrodes.

  This embodiment is an embodiment to which a metal mesh member is applied, as in the first embodiment, but if there is a solder absorption effect equivalent to this embodiment, punching metal other than the metal mesh member or A member in the form of expanded metal may be used.

It is sectional drawing showing the principal part of the semiconductor device concerning the 1st Embodiment of this invention. It is sectional drawing showing the principal part of the semiconductor device concerning the 2nd Embodiment of this invention. It is sectional drawing showing the principal part of another semiconductor device demonstrated in the 2nd Embodiment of this invention. It is sectional drawing showing the principal part of the semiconductor device concerning the 3rd Embodiment of this invention. It is a top view of the metal net-like member concerning the 3rd Embodiment of this invention. It is explanatory drawing of the manufacturing method of the semiconductor device concerning the 3rd Embodiment of this invention. It is sectional drawing showing the principal part of the semiconductor device concerning a prior art example. It is a figure for demonstrating the problem in a prior art example.

Explanation of symbols

1 Semiconductor element (diode chip)
2 First electrode (cathode electrode)
3 First lead 4 Second electrode (anode electrode)
5 Second lead 601, 602 Metal mesh member 602a Opening (hollow part)
7,701,702 Solder

Claims (6)

A first electrode having a first electrode on one surface of the semiconductor element, a second electrode on the other surface of the semiconductor element, wherein the first electrode is opposed to the first electrode; In the semiconductor device formed by bonding with a bonding material, and the second electrode is bonded with the second lead facing the second electrode with the bonding material,
At least one of the gap between the first electrode and the first lead and the gap between the second electrode and the second lead has a woven or non-woven shape made of metal wire or metal fiber. A member filled with a bonding material in the metal conductor, or a member filled with a bonding material in a thin plate-like metal conductor whose surface has been recessed or grooved, or a thin plate-like shape that has been processed to have a gap on the surface and inside A semiconductor comprising a metal conductor filled with a bonding material, the semiconductor element is sandwiched between the first lead and the second lead, and the electrode of the semiconductor element and the lead are bonded together. apparatus. A first electrode having a first electrode on one surface of the semiconductor element, a second electrode on the other surface of the semiconductor element, wherein the first electrode is opposed to the first electrode; In the semiconductor device formed by bonding with a bonding material, and the second electrode is bonded with the second lead facing the second electrode with the bonding material,
At least one of the first lead and the second lead is a member in which a woven or non-woven metal conductor made of a metal wire or metal fiber is filled with a bonding material, or a recess or groove is formed on the surface. The first lead is composed of a member obtained by filling a thin plate-like metal conductor with a bonding material, or a member obtained by filling a thin plate-shaped metal conductor having a void portion on the surface and inside with a bonding material. A semiconductor device characterized in that the semiconductor element is sandwiched between the second lead and the electrode of the semiconductor element and the lead are joined.   The semiconductor device according to claim 1, wherein the metal conductor has good wettability with the bonding material when heated.   The semiconductor device according to claim 1, wherein the bonding material is solder. A first electrode having a first electrode on one surface of the semiconductor element, a second electrode on the other surface of the semiconductor element, wherein the first electrode is opposed to the first electrode; In a method for manufacturing a semiconductor device, wherein the second electrode is bonded with a bonding material, and the second electrode is bonded with a second lead facing the second electrode with a bonding material.
At least one of the gap between the first electrode and the first lead and the gap between the second electrode and the second lead has a woven or non-woven shape made of metal wire or metal fiber. A member filled with a bonding material in the metal conductor, or a member filled with a bonding material in a thin plate-like metal conductor whose surface has been recessed or grooved, or a thin plate-like shape that has been processed to have a gap on the surface and inside A step of providing a member filled with a bonding material in a metal conductor; a step of sandwiching the semiconductor element between the first lead and the second lead; and a step of heating and melting the bonding material. A method for manufacturing a semiconductor device. A first electrode having a first electrode on one surface of the semiconductor element, a second electrode on the other surface of the semiconductor element, wherein the first electrode is opposed to the first electrode; In a method for manufacturing a semiconductor device, wherein the second electrode is bonded with a bonding material, and the second electrode is bonded with a second lead facing the second electrode with a bonding material.
A member in which at least one of the first lead and the second lead is bonded to a woven or non-woven metal conductor whose bonding material is a metal wire or metal fiber, or a depression or A step in which a thin plate-like metal conductor subjected to grooving is filled with a bonding material, or a thin plate-like metal conductor subjected to processing having a void portion on the surface and inside, and a member filled with the bonding material; A method of manufacturing a semiconductor device, comprising: a step of sandwiching the semiconductor element between a first lead and the second lead; and a step of heating and melting the bonding material.

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