JP2011204969A - Semiconductor element, semiconductor device, and conductive particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide conductive particles which have superior electric conductivity and heat dissipation, and to provide a semiconductor element and a semiconductor device that use the conductive particles to connect a terminal.SOLUTION: A conductive particle 400 consists of a core 41 made of resin and metal covering a surface of the core, and is characterized in that the core has a plurality of projections on its surface, the surface of the core is covered with a high-melting-point metal layer 42 having a melting point of 500°C or above, a surface of the high-melting-point metal layer 42 is covered with a low-melting-point metal layer 43 having a melting point of 280°C or below, and a surface of the low-melting-point metal layer is spherical.

Description

  The present invention relates to a semiconductor element, a semiconductor device, and conductive particles.

  Conventionally, when an electronic circuit board is connected to an IC or LSI chip, the board and the chip are connected by a wire by a wire bonding method.

  In recent years, substrates and ICs and LSIs are connected by protruding terminals called bumps arranged in an array. This connection method is called a flip chip method, and the mounting area can be reduced as compared with the conventional wire bonding method. In addition, since the wiring length is short, the electrical characteristics are excellent. It is suitable for portable device circuits that are strongly demanded for small size and thinness, and for high frequency circuits where electrical characteristics are important. In addition, because it is easy to transfer the heat of the chip to the substrate, it is also used for mounting products where heat generation is a problem. Since the input / output terminals are provided on the entire surface of the chip, the chip area can be reduced.

  In the conventional wire bonding method, since the input / output terminals are located at the periphery of the chip, the chip area has to be increased in order to arrange the necessary input / output terminals. However, the flip chip method does not require a wiring space by wires, so that the package itself can be made small. In addition, loss due to power supply noise, wiring inductance, and resistance can be reduced. However, even in the case of realizing the flip chip method, in recent years, it is necessary to improve electrical characteristics by improving the performance of high-frequency products, and improvement of heat dissipation characteristics found in LEDs and the like has been an issue.

JP 2005-317270 A

  In view of the above situation, the present invention is intended to improve electrical characteristics and heat dissipation.

  Conventionally, in the flip-chip connection method, conductive particles made mainly of an alloy of tin-lead, tin-zinc, and tin-silver have been used as bump materials. However, in recent years, copper has been used as a material for conductive particles in order to improve electrical characteristics and heat dissipation. Copper has material properties that it has several times higher conductivity and excellent heat dissipation than the above-described tin alloy (hereinafter referred to as solder material). On the other hand, since copper is easily oxidized, its characteristics are not stable. In addition, copper has a higher melting point, higher hardness, and difficulty in connection than conventional solder materials. Therefore, in actuality, it is assumed that copper that easily oxidizes is coated with a solder material. This is to solve the problem of oxidation and the problem of connectivity.

  Therefore, at present, due to the above problem, as shown in FIG. 1, it can be considered that the conductive material 100 has the solder material portion as the outer layer portion 12 and the copper material portion as the inner layer portion 11. Such conductive particles are used by utilizing the fact that the melting points of the two metals are different. As shown in FIG. 2C, when heat of about 250 ° C. is applied, only the solder material portion of the outer layer portion 12 melts, and the copper material portion of the inner layer portion 11 does not melt and is connected as a connection terminal portion. .

  At this time, the subject that the connection state of the copper part in the inner layer in electroconductive particle becomes unstable generate | occur | produces. Ideally, at the time of terminal connection, it is desirable that the connection surfaces of the board terminal connection portions are connected by copper portions in the bump inner layer portion at both two points. However, in reality, as shown in FIG. 2 (a), when both points are connected by a solder part in the outermost layer part, or as shown in FIG. 2 (b), one side is a solder part, and one side is There is a case where it is connected by a copper part. When connected in these situations, performance is not stable. In addition, the board connection terminal and the chip connection terminal are often made of a copper material, and for the purpose of improving the performance, the connection point between the board connection terminal and the copper part of the chip connection terminal and the copper part corresponding to the inner layer of the conductive particles. Since the copper material is connected to each other at two points, the performance in terms of conductivity and heat dissipation increases, so that there is a problem that it is desirable that the copper materials are in contact with each other at the two connection surfaces.

  According to the present invention, a connection terminal is formed between a conductive substrate and a semiconductor substrate by providing the internal structure of the conductive particle with a protrusion or a refractory metal fine particle structure. The present invention is described in detail below.

  In order to achieve the above object, the first semiconductor element of the present application includes a core part made of resin and conductive particles made of metal covering the surface of the core part, and the conductive particles are electrically connected to the electrode part. And the core has a plurality of protrusions on the surface, and the surface of the core is covered with a refractory metal layer having a melting point of 500 ° C. or higher. The surface of the high melting point metal layer is covered with a low melting point metal layer having a melting point of 280 ° C. or less, and the surface of the low melting point metal layer has a spherical surface.

  A first semiconductor device of the present application includes the semiconductor element and a substrate on which the semiconductor element is mounted, and a terminal of the substrate and an electrode portion of the semiconductor chip are electrically connected by the conductive particles. The terminal of the substrate and the refractory metal layer are in contact with each other, and the electrode portion of the semiconductor chip and the refractory metal layer are in contact with each other.

  The second semiconductor element of the present application includes a conductive particle composed of a resin core and a metal covering the surface of the core, and a semiconductor chip in which the conductive particle is electrically connected and fixed to the electrode portion. The core is spherical, the surface of the core is covered with a refractory metal layer having a melting point of 500 ° C. or higher, and the surface of the refractory metal layer has a low melting point of 280 ° C. or lower. The low melting point metal layer is covered with a melting point metal layer, and a high melting point metal piece having a melting point of 500 ° C. or higher is embedded in the low melting point metal layer, and the surface of the low melting point metal layer is spherical.

  A second semiconductor device of the present application includes the second semiconductor element and a substrate on which the semiconductor element is mounted, and the terminal of the substrate and the electrode portion of the semiconductor chip are electrically connected by the conductive particles. The terminal of the substrate is in contact with the refractory metal layer or the refractory metal piece, and the electrode portion of the semiconductor chip and the refractory metal layer or the refractory metal piece are It has the structure which is contacting.

  A third semiconductor element of the present application includes a core part and conductive particles made of a metal covering a surface of the core part, and a semiconductor chip in which the conductive particles are electrically connected and fixed to an electrode part, The core is spherical and is made of a high melting point metal having a melting point of 500 ° C. or higher. The surface of the core is covered with a low melting point metal layer having a melting point of 280 ° C. or lower. Has a structure in which a high melting point metal piece having a melting point of 500 ° C. or higher is embedded, and the surface of the low melting point metal layer is a spherical surface.

  A third semiconductor device of the present application includes the third semiconductor element and a substrate on which the semiconductor element is mounted, and the terminal of the substrate and the electrode portion of the semiconductor chip are electrically connected by the conductive particles. And the terminal of the substrate is in contact with the core or the refractory metal piece, and the electrode portion of the semiconductor chip is in contact with the core or the refractory metal piece. It has a configuration.

  The first conductive particle of the present application includes a core portion made of a resin and a metal that covers a surface of the core portion, and the core portion has a plurality of protrusions on a surface thereof. The surface is covered with a refractory metal layer having a melting point of 500 ° C. or higher, and the surface of the refractory metal layer is covered with a low melting point metal layer having a melting point of 280 ° C. or less. The surface has a configuration of a spherical surface.

  The second conductive particle of the present application is composed of a core part made of resin and a metal covering the surface of the core part, the core part is spherical, and the surface of the core part has a melting point of 500 ° C. or higher. Covered with a refractory metal layer, the surface of the refractory metal layer is covered with a low melting point metal layer having a melting point of 280 ° C. or lower, and the low melting point metal layer has a high melting point of 500 ° C. or higher. A melting point metal piece is embedded, and the low melting point metal layer has a spherical surface.

  The third conductive particles of the present application are composed of a core part and a metal covering the surface of the core part, the core part is spherical, and is made of a refractory metal having a melting point of 500 ° C. or more. The surface of the portion is covered with a low melting point metal layer having a melting point of 280 ° C. or lower, and a high melting point metal piece having a melting point of 500 ° C. or higher is embedded in the low melting point metal layer. The surface of is provided with the structure which is a spherical surface.

  According to the present invention, the conductive particles can be produced by a simple manufacturing method, and the refractory metal part having excellent conductivity and heat dissipation in the inner part of the conductive particle is always used as the substrate terminal part and the chip terminal part. It can be securely connected. Therefore, it is possible to improve the performance of the entire semiconductor product and stabilize the performance. In addition, it is possible to connect between the substrate terminals and the chip terminals using the conductive particles according to the present invention without changing the conventional production equipment, and also according to the present invention from the viewpoint of semiconductor production efficiency. Conductive particles are effective.

These are sectional drawings of conventional conductive particles. (A)-(c) is sectional drawing of the board | substrate connection by the conventional electroconductive particle shown to Fig.1 (a). (A) is electroconductive particle sectional drawing which concerns on 1st Embodiment, (b) is electroconductive particle sectional drawing which concerns on a modification. (A) is electroconductive particle sectional drawing which concerns on 2nd Embodiment, (b) is electroconductive particle sectional drawing which concerns on a modification. (A) is sectional drawing at the time of the board | substrate connection of the semiconductor chip which concerns on 1st Embodiment, (b) is sectional drawing at the time of the board | substrate connection of the semiconductor chip concerning a modification. (A) is sectional drawing at the time of the board | substrate connection of the semiconductor chip which concerns on 2nd Embodiment, (b) is sectional drawing at the time of the board | substrate connection of the semiconductor chip concerning a modification.

  In the present invention, when the term “sphere” is used, such as the spherical core or the surface of the low melting point metal layer is a spherical surface, it does not mean a sphere in a mathematically exact sense, but an industrial In other words, it means a shape that can be actually produced including variations in shape and size when it is produced aiming at a sphere and can be used without any problem in a semiconductor device.

  In one embodiment, the spherical resin portion serving as the core of the conductive particles is uneven. The outer layer is coated with a refractory metal (mainly copper is desirable) by electroless plating or electrolytic plating. Assuming that the diameter of the conductive particles is 100, assuming that the conductive particles are used as the conductive particles, the diameter of the core resin is about half that of the core resin, and about 25% of the diameter of the core resin. Make irregularities. As for how to make unevenness, press the resin at high temperature to make unevenness. Alternatively, unevenness is made by scratching the spherical resin surface. Or the implementation method of welding a small piece of resin on the resin surface may be sufficient. Coating or plating a refractory metal on the resin outer layer that becomes the core with unevenness. The thickness to be coated may be 5 μm to 20 μm. Further, a low melting point metal (tin-lead alloy, tin-silver alloy, tin-zinc alloy) is coated on the outermost layer. After coating, it is molded into a spherical shape using the surface tension of the alloy. The appearance and method of use are the same as those of conventional conductive particles made of only a low melting point metal. When the conductive particles according to the present invention are used, the low melting point metal part is melted first, and the concavo-convex part of the high melting point metal part inside is in contact with and connected to the substrate terminal part or chip terminal part, and the current is conducted. Thus, it is possible to stably ensure conductivity and heat dissipation.

  In one embodiment, after the inner layer portion is coated with a refractory metal on the conductive particles, a small piece of the refractory metal is deposited on the outer layer. Further, a low melting point metal (a tin-lead alloy, a tin-silver alloy, or a tin-zinc alloy is desirable) is coated on the outer layer. After coating, it is molded into a sphere using surface tension. Appearance and usage are the same as those of conductive particles composed only of low melting point metals that have been used conventionally. When this conductive particle is used, the low melting point metal part is first melted and the uneven part of the high melting point metal part and the high melting point metal piece part are in contact with and connected to the substrate terminal part or the chip terminal part, so that the current flows. By being conducted, it is possible to stably ensure conductivity and heat dissipation.

  In another embodiment, a refractory metal (mainly copper is desirable) is coated by electroless plating or electrolytic plating on the outer layer of a spherical resin serving as a core of conductive particles. Assuming that the diameter of the conductive particles is 100, assuming that the conductive particles are used as conductive particles, the diameter of the resin part that is the core is about half that, and the high melting point metal is coated around the core part coated with the high melting point metal. Weld small pieces. Further, a low melting point metal (a tin-lead alloy, a tin-silver alloy, or a tin-zinc alloy is desirable) is coated on the outer layer. After coating, it is molded into a sphere using surface tension. Appearance and usage are the same as those of conductive particles composed only of low melting point metals that have been used conventionally. When this conductive particle is used, the low melting point metal part is first melted and the uneven part of the high melting point metal part and the high melting point metal piece part are in contact with and connected to the substrate terminal part or the chip terminal part, so that the current flows. By being conducted, it is possible to stably ensure conductivity and heat dissipation.

  In another embodiment, the sphere shape used as the core of the conductive particles is made of a refractory metal. A refractory metal piece is deposited around a core composed of a refractory metal. Further, a low melting point metal (a tin-lead alloy, a tin-silver alloy, or a tin-zinc alloy is desirable) is coated on the outer layer. After coating, it is molded into a spherical shape by the surface tension of the low melting point metal. From the present invention, the appearance and method of use are the same as conventional conductive particles. When this conductive particle according to the present invention is used, the low melting point metal part melts and the internal high melting point metal part piece comes into contact with and is connected to the substrate terminal part or chip terminal part, so that the current is conducted. It is possible to ensure stable heat dissipation.

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

(First embodiment)
FIG. 3A schematically shows a cross-sectional structure of the conductive particle 400 according to the first embodiment. The conductive particle 400 shown in FIG. 3A has a resin core 41 having a rough surface. That is, by providing a plurality (a large number) of protrusions on the surface, the resin core 41 is uneven. Further, the high-melting point metal 42 is coated on the resin core outer layer portion. The resin core 41 of the conductive particles is preferably about half the diameter of the conductive particles. The height of the unevenness of the resin core part is preferably 10 to 50% of the diameter of the resin core part 41. As a method of making the unevenness, the unevenness is made by scratching the surface of the resin sphere. Alternatively, since the core is made of resin, it is possible to make irregularities by molding with a high-pressure press. Alternatively, a method of adhering or welding fine protrusions on the surface of the resin sphere may be used. The means for providing the unevenness is not limited to the above.

  A high melting point metal layer 42 (preferably copper) is formed on the outer layer of the resin core 41 having irregularities by coating or plating. Here, the high melting point metal means a metal having a melting point of 500 ° C. or higher, and the same as the high melting point metal layer 42 used for coating or plating the outer layer of the resin core 41 in the substrate connection terminal or the chip connection terminal. It is preferable to comprise with the material of. Usually, the refractory metal layer 42 is coated or plated using electroless plating or chemical plating, but any means may be used. Further, the present invention is not limited to the coating and plating means. The plating thickness is set to a thickness that does not exceed the height of the unevenness, and the unevenness shape is maintained even in the form of coating of the refractory metal layer 42 or after plating.

  Thereafter, the surface of the high melting point metal layer 42 is further coated with a low melting point metal layer 43 (an alloy of tin-lead, tin-silver, tin-zinc is desirable) and molded into a sphere. Here, the low melting point metal is a metal having a melting point of 280 ° C. or lower. It is formed into a sphere using the surface tension of a low melting point metal. Alternatively, a metal having a high melting point metal coated or plated is placed in a mold, and a low melting point metal is poured into the sphere to form it. The present invention is not limited in the method and means for making the outer shape of the low melting point metal layer 43 spherical.

  Usually, the diameter of the conductive particles 400 is assumed to be 10 μm to 200 μm, but the upper limit is not particularly defined. The diameter is preferably 50 μm to 150 μm, and more preferably 70 μm to 100 μm.

  The conductive particles 400 according to the present embodiment are thermally welded and fixed to a semiconductor substrate terminal portion (an electrode portion of the semiconductor chip) of the semiconductor chip to form a connection terminal of the semiconductor chip. Further, the conductive particles 400 are positioned between the substrate terminal (substrate electrode terminal) 25 and the semiconductor substrate terminal portion 21 shown in FIG. In FIG. 5A, it is between the substrate terminal 25 and the semiconductor substrate terminal portion 21, but includes the case between the substrate terminals or between the chip terminals. Further, the terminal portion material of the substrate terminal 25 is made of the same material as the refractory metal used for the conductive particles (preferably copper). 2 is a part of the semiconductor chip and 20 is a semiconductor substrate. 4 is a part of the semiconductor device, and 22 is a circuit board.

  Conductive particles are sandwiched and connected between the substrate terminal 25 and the semiconductor substrate terminal portion 21, and in this state, welding or pressure bonding is performed. In that state, heat (for example, around 250 ° C.) is applied. Or apply ultrasound as needed. In that case, the low melting point metal layer 43 in the outermost layer of the conductive particles 400 is melted and welded onto the substrate terminal 25 and the semiconductor substrate terminal portion 21. At this time, the refractory metal layer 42 in the inner layer does not melt, and the refractory metal layer 42 contacts the substrate terminal 25 and the semiconductor substrate terminal portion 21 by melting the low melting point metal layer 43. As a result, current is conducted through the conductive particles 400.

  At this time, since the refractory metal layer 42 does not melt, the protrusion of the refractory metal layer 42 comes into contact with the substrate terminal 25 and the semiconductor substrate terminal portion 21 and is conducted. Since the high melting point metal layer 42 has higher electrical conductivity and heat dissipation than the low melting point metal layer 43, the performance of the material characteristics is ensured. In addition, since the refractory metal layer 42 can always be in contact with the substrate terminal 25 and the semiconductor substrate terminal portion 21, the performance is always stable, between the fixed substrate terminal and the chip terminal, and between the substrate connection terminals. Alternatively, the connection between the chip connection terminals is made possible.

  FIG. 3B schematically shows a cross-sectional structure of the conductive particles 410 according to the modification of the first embodiment. The conductive particles 410 shown in FIG. 3 (b) have a resin core portion 41 with an uneven surface, and coat the refractory metal layer 42 on the outer layer of the resin core portion 41. The resin core 41 of the conductive particles has a diameter that is approximately half the diameter of the conductive particles. With respect to the resin core 41, the height of the irregularities is preferably 10 to 50% of the diameter of the resin core 41. There is a method of scratching the surface of the resin sphere as a method of making the unevenness. Alternatively, since the core is a resin, it may be uneven by molding by pressing. Alternatively, a method of adhering or welding fine protrusions on the surface of the resin sphere may be used. The means for providing the unevenness is not limited to the above.

  The surface of the resin core 41 with unevenness is coated or plated with a refractory metal layer 42 (preferably copper). Here, it is preferable that the substrate terminal 25 or the semiconductor substrate terminal portion (chip connection terminal) 21 is also made of the same material as the refractory metal used for coating or plating the outer layer of the resin core 41. Usually, the refractory metal layer 42 is coated or plated using electroless plating or chemical plating, but any means may be used. Further, the present invention is not limited to the coating and plating means. The plating thickness is set to a thickness that does not exceed the height of the unevenness, and the uneven shape is maintained even in the form after the refractory metal coating or plating.

  Further, a refractory metal piece 44 is welded or adhered to the refractory metal layer 42. There is no problem as long as the size of the refractory metal piece 44 falls between the conductive particle 410 and the rugged surface outer layer portion of the refractory metal layer 42 when the refractory metal piece 44 is attached to the refractory metal layer 42. . That is, the high melting point metal piece 54 only needs to be embedded in the low melting point metal layer 53. The size of the refractory metal piece 44 is not limited as long as it does not exceed the diameter of the conductive particles 410. In the drawing, a spherical refractory metal piece 44 is shown, but the shape is not limited as necessary. Further, the present invention is not limited in its shape.

  Thereafter, a low melting point metal layer 43 (a tin-lead, tin-silver, or tin-zinc alloy is desirable) is coated on the outer layer and formed into a spherical shape. It is formed into a sphere using the surface tension of a low melting point metal. Alternatively, a high melting point metal coated or plated is placed in a mold, and a low melting point metal is poured into a sphere. The present invention is not limited in the method and means for making the low melting point metal spherical.

  Usually, the diameter of the conductive particles 410 is assumed to be 10 μm to 200 μm, but the upper limit is not particularly defined. The diameter is preferably 50 μm to 150 μm, and more preferably 70 μm to 100 μm.

  The conductive particles 410 are thermally welded and fixed to a semiconductor substrate terminal portion (an electrode portion of the semiconductor chip) of the semiconductor chip to form a connection terminal of the semiconductor chip. Further, the conductive particles 410 are positioned between the substrate terminal (substrate electrode terminal) 25 and the semiconductor substrate terminal portion 21 shown in FIG. In FIG. 5B, it is between the substrate terminal 25 and the semiconductor substrate terminal portion 21, but includes the case between the substrate terminals or between the chip terminals. The material of the substrate terminal 25 is made of a refractory metal (copper is desirable).

  In this state, when heat (for example, around 250 ° C.) or ultrasonic waves are applied as necessary, the low melting point metal layer 43 as the outermost layer of the conductive particles 410 is melted, and the substrate terminals 25 and the semiconductor substrate terminal portions 21 are formed. To weld. At this time, the refractory metal layer 42 in the inner layer is not melted, and the refractory metal layer 43 or the refractory metal piece 43 attached to the refractory metal layer 42 as a result of the melting of the low melting metal layer 43 becomes the substrate terminal 25 and Contact the semiconductor substrate terminal portion 21. As a result, current is conducted between the substrate terminals 25 and the semiconductor substrate terminal portions 21, between the chip input / output terminals, and between the substrate terminals 25 through the conductive particles 410.

  At this time, since the refractory metal layer 42 is not melted, the concavo-convex portion on the surface of the refractory metal layer 42 is brought into contact with the substrate terminal 21 or the chip terminal portion to be conducted. Since the high melting point metal layer 42 and the high melting point metal piece 44 have higher electrical conductivity and heat dissipation than the low melting point metal layer 43, the performance of the material characteristics is secured, and the high melting point metal layer 42 and the high melting point metal piece 44 are the substrate terminals. 25 and the semiconductor substrate terminal portion 21 can be always in contact with each other, so that the performance is always stable and the connection between the substrate connection terminals or the chip connection terminals can be made constant.

(Second Embodiment)
FIG. 4A schematically shows a cross-sectional structure of the conductive particles 500 according to the second embodiment. In the conductive particles 500 shown in FIG. 4A, the high melting point metal is the nucleus 50 of the conductive particles 500. A high melting point metal piece 54 is welded or bonded to the surface. Further, the low melting point metal layer 53 is coated so as to include a high melting point metal piece 54 attached to the outside of the high melting point metal layer 52, and formed into a spherical shape.

  The size of the refractory metal piece 54 may be any size as long as it fits between the outermost layer of the conductive particles 500 and the surface of the nucleus 50 when attached. That is, the high melting point metal piece 54 only needs to be embedded in the low melting point metal layer 53. Further, any material that is smaller than the diameter of the conductive particles 500 when the refractory metal piece 54 is attached may be used. Moreover, it does not ask about the number of small pieces. Further, although the refractory metal piece 54 having a spherical shape is shown in the drawing, the shape thereof may be changed as necessary. Further, the present invention is not limited in its shape. As a result, the low melting point metal layer 53 is coated on the outermost layer and formed into a sphere. As a method of making the surface of the low melting point metal layer 53 into a spherical shape, the surface tension of the material is used to form a spherical body. Alternatively, there is a method in which a high melting point metal piece 54 is attached and placed in a mold and a low melting point metal is placed into a sphere. The means for forming the conductive particles into a sphere is not limited to the present invention.

  Usually, the diameter of the conductive particles 500 is assumed to be 10 μm to 200 μm, but the upper limit is not particularly defined. The diameter is preferably 50 μm to 150 μm, and more preferably 70 μm to 100 μm.

  At the time of actual connection, the conductive particles 500 according to the present embodiment are thermally welded and fixed to a semiconductor substrate terminal portion (an electrode portion of the semiconductor chip) of the semiconductor chip to form a connection terminal of the semiconductor chip. Further, the conductive particles 500 are positioned between the substrate terminal (substrate electrode terminal) 25 and the semiconductor substrate terminal portion 21 shown in FIG. In FIG. 6A, the position of the conductive particles 500 is between the substrate terminal 25 and the semiconductor substrate terminal portion 21, but includes the case between the substrate terminals or between the chip terminals. The material of the substrate connection terminal 25 is made of a refractory metal (copper is desirable).

  In this state, heat (for example, around 250 ° C.) is applied. Apply ultrasonic waves as necessary. In this case, the low melting point metal layer 53 that is the outermost layer of the conductive particles 500 is melted and welded onto the substrate terminal 25 and the semiconductor substrate terminal portion 21. At this time, the nucleus 50 in the inner layer does not melt, and the low melting point metal layer 53 melts. As a result, the core 50 or the refractory metal piece 54 attached to the outer surface of the core 50 contacts and connects to the substrate terminal 25 and the semiconductor substrate terminal portion 21. As a result, current is conducted in the substrate terminal 25 and the semiconductor substrate terminal portion 21 through the conductive particles 500.

  At this time, since the nucleus 50 does not melt, the nucleus 50 or the refractory metal piece 54 comes into contact with the substrate terminal 25 and the semiconductor substrate terminal portion 21 and is conducted. Since the core 50 or the high melting point metal piece 54 has higher electrical conductivity and heat dissipation than the low melting point metal layer 53, the performance of its electrical characteristics is ensured. Further, since the core 50 or the refractory metal piece 54 can always be in contact with the substrate terminal 25 and the semiconductor substrate terminal portion 21, it becomes a connection between the refractory metals and the performance is drawn out. Moreover, since the high melting point metals are always in contact with each other, the performance is stabilized and becomes constant.

  FIG. 4B schematically shows a cross-sectional structure of the conductive particles 510 according to the modification of the second embodiment. The conductive particles 510 shown in FIG. 4B have a resin core 51 that is a sphere, and the resin core 51 is the core of the conductive particles 510. A refractory metal layer 52 is formed on the outer layer by coating or plating. Further, a refractory metal piece 54 is welded or adhered to the outer layer portion. Further, the low melting point metal layer 53 is coated so as to include the high melting point metal piece 54 attached to the outer surface of the high melting point metal layer 52 and formed into a spherical shape. The size of the refractory metal piece 54 is preferably such that it fits between the outermost layer of the conductive particles 510 and the outer surface of the refractory metal 52 when attached to the outer surface of the refractory metal layer 52. Further, the size is not limited as long as it does not exceed the diameter of the conductive particles 510 minus the thickness of the low melting point metal when the high melting point metal piece 54 is attached. Further, the number of small pieces is not limited in the present invention. Moreover, although the refractory metal piece 54 having a spherical shape is illustrated in the drawing, the shape thereof may be changed as necessary. Further, the present invention is not limited by the shape of the refractory metal piece 54.

  Finally, the low melting point metal layer 53 is coated on the outermost layer and formed into a sphere. As for the method of making the surface of the low melting point metal layer 53 into a spherical shape, it is formed into a spherical shape by utilizing the surface tension which is a characteristic of the material. Alternatively, in a state where the high melting point metal piece 54 is adhered, the low melting point metal is put into a mold and molded. The present invention is not limited in the means for forming a spherical body as conductive particles.

  Usually, the diameter of the conductive particles 510 is assumed to be 10 μm to 200 μm, but the upper limit is not particularly defined. The diameter is preferably 50 μm to 150 μm, and more preferably 70 μm to 100 μm.

  Examples using the conductive particles 510 according to this modification will be described below. The conductive particles 510 according to this modification are thermally welded and fixed to the semiconductor substrate terminal portion of the semiconductor chip (electrode portion of the semiconductor chip) to form a connection terminal of the semiconductor chip. Further, the conductive particles 510 are positioned between the substrate terminal (substrate electrode terminal) 25 and the semiconductor substrate terminal portion 21 shown in FIG. In FIG. 6B, the position of the conductive particles 510 is between the substrate terminal 25 and the semiconductor substrate terminal portion 21, but includes the case between the substrate terminals or between the chip terminals. The material of the substrate terminal 21 is made of a refractory metal (copper is desirable).

  In this state, heat (for example, around 250 ° C.) and ultrasonic waves are applied as necessary. In this case, the low melting point metal layer 53 which is the outermost layer of the conductive particles 510 is melted and welded onto the substrate terminal 25 and the semiconductor substrate terminal portion 21. At this time, the high melting point metal layer 52 in the inner layer does not melt, and the low melting point metal layer 53 melts. As a result, the refractory metal piece 54 attached to the outer surface of the refractory metal layer 52 or the outer surface of the refractory metal 52 contacts the substrate terminal 25 and the semiconductor substrate terminal portion 21. As a result, current is conducted in the substrate terminal 25 and the semiconductor substrate terminal portion 21 through the conductive particles 510.

  At this time, since the refractory metal layer 52 does not melt, the outer surface of the refractory metal layer 52 or the refractory metal piece 54 comes into contact with the substrate terminal 25 and the semiconductor substrate terminal portion 21 to be conducted. Since the high melting point metal layer 52 or the high melting point metal piece 54 has higher electrical conductivity and heat dissipation than the low melting point metal 53, the performance of its electrical characteristics is ensured. In addition, since the refractory metal layer 52 or the refractory metal piece 54 can always be in contact with the substrate connection terminal 25 and the semiconductor substrate terminal portion 21, the refractory metal is connected to each other, and the performance is drawn out. The performance is stabilized and stabilized because of contact with metal.

  INDUSTRIAL APPLICABILITY The present invention can be used as a connection terminal between substrate terminals used between flip chips and the like, and a connection terminal between chip terminals.

2 Part of semiconductor chip 4 Part of semiconductor device 10 Core 11 made of resin material High melting point metal 12 Low melting point metal 20 Substrate 21 Semiconductor substrate terminal part (semiconductor chip terminal part)
22 Circuit board 25 Board terminal 41 Core (core part) made of resin material shaped into irregularities
42 High-melting-point metal layer 43 Low-melting-point metal layer 44 High-melting-point metal piece 50 Core 51 Core 52 made of resin material High-melting-point metal layer 53 Low-melting-point metal layer 54 High-melting-point metal piece 400 Conductive particle 410 Conductive particle 500 Conductive Conductive particles 510 conductive particles

Claims (33)

A semiconductor element comprising: a core made of resin; conductive particles made of metal covering a surface of the core; and a semiconductor chip in which the conductive particles are electrically connected and fixed to an electrode part,
The core has a plurality of protrusions on the surface,
The surface of the core is covered with a refractory metal layer having a melting point of 500 ° C. or higher,
The surface of the high melting point metal layer is covered with a low melting point metal layer having a melting point of 280 ° C. or less,
The semiconductor element, wherein a surface of the low melting point metal layer is a spherical surface.   The semiconductor device according to claim 1, wherein the refractory metal layer is made of copper.   The low-melting-point metal layer is made of one kind selected from an alloy of tin and lead, an alloy of tin and silver, and an alloy of tin and zinc. Semiconductor element.   4. The semiconductor device according to claim 1, wherein the low melting point metal layer is made of a metal having a melting point of 250 ° C. or less. 5.   5. The semiconductor element according to claim 1, wherein a piece of a high melting point metal having a melting point of 500 ° C. or higher is embedded in the low melting point metal layer.   The semiconductor element according to claim 5, wherein the refractory metal piece is made of copper. A semiconductor element comprising: a conductive core composed of a resin core and a metal covering a surface of the core; and a semiconductor chip in which the conductive particle is electrically connected and fixed to an electrode portion,
The core is spherical,
The surface of the core is covered with a refractory metal layer having a melting point of 500 ° C. or higher,
The surface of the high melting point metal layer is covered with a low melting point metal layer having a melting point of 280 ° C. or less,
In the low melting point metal layer, a high melting point metal piece having a melting point of 500 ° C. or higher is embedded,
The semiconductor element, wherein a surface of the low melting point metal layer is a spherical surface.   The semiconductor device according to claim 7, wherein the refractory metal layer is made of copper.   9. The semiconductor element according to claim 7, wherein the refractory metal piece is made of copper.   The low-melting-point metal layer is made of one kind selected from an alloy of tin and lead, an alloy of tin and silver, and an alloy of tin and zinc. The semiconductor element according to one.   11. The semiconductor device according to claim 7, wherein the low melting point metal layer is made of a metal having a melting point of 250 ° C. or less. A semiconductor element comprising: a core part; conductive particles made of metal covering a surface of the core part; and a semiconductor chip in which the conductive particles are electrically connected and fixed to an electrode part,
The core part is spherical and made of a refractory metal having a melting point of 500 ° C. or higher,
The surface of the core is covered with a low melting point metal layer having a melting point of 280 ° C. or less,
In the low melting point metal layer, a high melting point metal piece having a melting point of 500 ° C. or higher is embedded,
The semiconductor element, wherein a surface of the low melting point metal layer is a spherical surface.   The semiconductor element according to claim 12, wherein the core is made of copper.   The low-melting-point metal layer is made of one selected from an alloy of tin and lead, an alloy of tin and silver, and an alloy of tin and zinc. Semiconductor element.   15. The semiconductor element according to claim 12, wherein the low melting point metal layer is made of a metal having a melting point of 250 [deg.] C. or less. A semiconductor device comprising: the semiconductor element according to claim 1; and a substrate on which the semiconductor element is mounted.
The terminal of the substrate and the electrode portion of the semiconductor chip are electrically connected by the conductive particles,
The terminal of the substrate and the refractory metal layer are in contact;
A semiconductor device, wherein an electrode portion of the semiconductor chip and the refractory metal layer are in contact with each other. A semiconductor device comprising: the semiconductor element according to any one of claims 5 to 11; and a substrate on which the semiconductor element is mounted.
The terminal of the substrate and the electrode portion of the semiconductor chip are electrically connected by the conductive particles,
The terminal of the substrate is in contact with the refractory metal layer or the refractory metal piece,
A semiconductor device, wherein an electrode portion of the semiconductor chip is in contact with the refractory metal layer or the refractory metal piece. A semiconductor device comprising: the semiconductor element according to claim 12; and a substrate on which the semiconductor element is mounted.
The terminal of the substrate and the electrode portion of the semiconductor chip are electrically connected by the conductive particles,
The terminal of the substrate is in contact with the core or the refractory metal piece;
A semiconductor device, wherein an electrode portion of the semiconductor chip is in contact with the core portion or the refractory metal piece. Conductive particles comprising a core part made of resin and a metal covering the surface of the core part,
The core has a plurality of protrusions on the surface,
The surface of the core is covered with a refractory metal layer having a melting point of 500 ° C. or higher,
The surface of the high melting point metal layer is covered with a low melting point metal layer having a melting point of 280 ° C. or less,
Conductive particles, wherein the surface of the low melting point metal layer is spherical.   The conductive particles according to claim 19, wherein the refractory metal layer is made of copper.   21. The low-melting-point metal layer is made of one selected from an alloy of tin and lead, an alloy of tin and silver, and an alloy of tin and zinc. Conductive particles.   The conductive particles according to any one of claims 19 to 21, wherein the low melting point metal layer is made of a metal having a melting point of 250 ° C or lower.   The conductive particles according to any one of claims 19 to 22, wherein the low melting point metal layer is embedded with a high melting point metal piece having a melting point of 500 ° C or higher.   The conductive particles according to claim 23, wherein the refractory metal piece is made of copper. Conductive particles comprising a core part made of resin and a metal covering the surface of the core part,
The core is spherical,
The surface of the core is covered with a refractory metal layer having a melting point of 500 ° C. or higher,
The surface of the high melting point metal layer is covered with a low melting point metal layer having a melting point of 280 ° C. or less,
In the low melting point metal layer, a high melting point metal piece having a melting point of 500 ° C. or higher is embedded,
Conductive particles, wherein the surface of the low melting point metal layer is spherical.   The conductive particles according to claim 25, wherein the refractory metal layer is made of copper.   27. The conductive particle according to claim 25 or 26, wherein the refractory metal piece is made of copper.   The low-melting-point metal layer is made of one selected from an alloy of tin and lead, an alloy of tin and silver, and an alloy of tin and zinc. The electroconductive particle as described in one.   The conductive particles according to any one of claims 25 to 28, wherein the low-melting-point metal layer is made of a metal having a melting point of 250 ° C or lower. Conductive particles comprising a core and a metal covering the surface of the core,
The core part is spherical and made of a refractory metal having a melting point of 500 ° C. or higher,
The surface of the core is covered with a low melting point metal layer having a melting point of 280 ° C. or less,
In the low melting point metal layer, a high melting point metal piece having a melting point of 500 ° C. or higher is embedded,
Conductive particles, wherein the surface of the low melting point metal layer is spherical.   The conductive particle according to claim 30, wherein the core portion is made of copper.   The low-melting-point metal layer is made of one selected from an alloy of tin and lead, an alloy of tin and silver, and an alloy of tin and zinc. Conductive particles.   The conductive particles according to any one of claims 30 to 32, wherein the low-melting-point metal layer is made of a metal having a melting point of 250 ° C or lower.

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