JP2005064536A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an external connecting projection that has a high aspect ratio and reduces an amount of a metal to be used which becomes the material of the projection; and also to provide a method of forming the projection and a semiconductor chip, circuit board, and electronic equipment using the projection. <P>SOLUTION: In the external connecting projection 10, a resin-made projecting body 22 is provided adjacently to an electrode pad 20, and a metallic conductor 24 is formed astride another electrode pad 14 and the projecting body 22. Since the external connecting projection 10 is constituted in this way, the projection 10 having the high aspect ratio is formed easily. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an external connection protrusion and a method of forming the same, a semiconductor chip, a circuit board, and an electronic device, and more particularly to an external connection protrusion having a high aspect ratio, a semiconductor chip having the external connection protrusion, a circuit substrate, and an electronic device.

  In the mounting of semiconductor chips, in recent years, a flip chip mounting method in which connection is performed using solder bumps is often used. That is, bumps are formed on an active element forming surface (hereinafter referred to as an active surface) of a semiconductor chip by a plating method, a vapor deposition method, or a method in which a substantially spherical solder ball is previously placed on an electrode pad, and these are used. The semiconductor chip is connected to the substrate.

  However, in recent years, with the miniaturization of semiconductor chips, it is required to reduce the distance between bumps formed on an LSI chip, that is, to reduce the pitch. Therefore, a bump having a high aspect ratio, that is, having a height higher than its width is required. In view of this, for example, a method of forming bumps as in the invention of Japanese Patent Laid-Open No. 10-107038 has been considered. That is, solder containing zinc (Zn) and antimony (Sb) is bonded onto the electrode pad on the active surface, and conductive particles are bonded onto the solder.

  However, when the formation method as described above is used, the amount of metal used to form the bumps increases as the bumps are raised. Therefore, when expensive gold is used, it becomes a factor of cost increase. In addition, since the manufacturing process is more complicated than the conventional one in order to increase the bump, this also causes an increase in cost.

  Accordingly, the present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art, and has an external connection protrusion having a high aspect ratio and capable of reducing the amount of metal used as a material, and the formation thereof. It is an object of the present invention to provide a method, and a semiconductor chip, a circuit board, and an electronic device using the method.

  In order to achieve the above object, the present invention provides an external connection protrusion formed on an active element forming surface of a semiconductor chip, a protrusion formed near the electrode of the semiconductor chip, the electrode, And a conductor formed continuously on the protrusion.

  In the present invention configured as described above, the external connection protrusion is composed of a protrusion and a conductor, the protrusion is formed at a predetermined height, and the conductor is formed thereon, so that the aspect ratio is high. External connection protrusions can be easily formed.

  Note that the conductor is preferably formed of gold (Au), copper (Cu), or nickel (Ni).

  In the external connection protrusion, the conductor is formed so as to cover the top of the protrusion.

  In the present invention configured as described above, since the top portion of the projecting body can be used for electrical connection, an external connection projection having a high aspect ratio can be obtained.

  In the above external connection projection, the top of the projection is formed flat.

  In the present invention configured as described above, it is possible to increase the contact area between the protrusion and the wiring pattern of the substrate, and it is possible to ensure the electrical continuity thereof more reliably.

  In the external connection protrusion, the protrusion is formed in parallel to the electrode array and in the vicinity of the electrode, and the conductor is formed for each of the electrodes. did.

  In the present invention configured as described above, one external connection protrusion can be used for electrical connection of a plurality of electrodes.

  In the external connection protrusion, the protrusion is formed in a frame shape in a region surrounded by the electrode on the active element formation surface.

  In the present invention configured as described above, the external connection protrusion can be used for electrical connection of all electrodes formed on the semiconductor chip.

  In the external connection protrusion, the protrusion is made of resin.

  In the present invention configured as described above, the projecting body can be easily formed in a predetermined shape and height. Moreover, since the protrusion has flexibility, external stress can be absorbed by the external connection protrusion.

  Further, the external connection protrusion formed on the active element forming surface of the semiconductor chip is formed into a bottomed cylindrical shape on the electrode of the semiconductor chip.

  In the present invention configured as described above, since the external connection protrusion is hollow, the amount of material used to form the external connection protrusion can be reduced.

  The semiconductor chip is characterized in that the external connection protrusion described above is formed in a semiconductor chip.

  According to the present invention configured as described above, it is possible to provide a semiconductor chip in which the external connection protrusions are arranged at a narrower pitch than the conventional one. As a result, the semiconductor chip itself can be miniaturized.

  In addition, any one of the semiconductor chips described above is mounted on a circuit board.

  In the present invention configured as described above, a circuit board that is smaller than the conventional one can be provided.

  Furthermore, an electronic apparatus has the above-described circuit board.

  In the present invention configured as described above, since the circuit board that is smaller than the conventional one is used, it is easy to reduce the size of the electronic device itself.

  And in the method of forming the external connection protrusion on the semiconductor wafer, the step of adhering a protrusion in the vicinity of the electrode formed on the semiconductor wafer, and the conductor on the electrode and the protrusion by plating. And a step of forming at least.

  In the present invention configured as described above, it is possible to easily form external connection protrusions having a predetermined size and height near the electrodes of the semiconductor chip.

  As described above, according to the present invention, in a semiconductor chip formed with an electrode, a protruding portion that is connected to the electrode and protrudes in parallel with the active element forming surface of the semiconductor chip is formed. Therefore, it is possible to easily form external connection protrusions having a high aspect ratio and a small amount of metal used as a material. In addition, this contributes to the miniaturization of the semiconductor chip on which the external connection protrusion is formed, the circuit board on which the semiconductor chip is mounted, and the electronic device including the circuit board. In addition, it contributes significantly to these cost reductions.

  Hereinafter, preferred embodiments of an external connection protrusion and a method for forming the same, a semiconductor chip, a circuit board, and an electronic device according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view of an external connection protrusion according to the first embodiment of the present invention. Moreover, FIG. 2 is sectional drawing which shows the modification of the external connection protrusion which concerns on the 1st Embodiment of this invention. Moreover, FIG. 3 is sectional drawing which shows the modification of the external connection protrusion which concerns on the 1st Embodiment of this invention. FIG. 4 is a cross-sectional view of the external connection protrusion according to the second embodiment of the present invention. FIG. 5 is a perspective view of an external connection protrusion according to the third embodiment of the present invention. FIG. 6 is a plan view of an external connection protrusion according to the fourth embodiment of the present invention. Moreover, FIG. 7 is explanatory drawing of the manufacturing process of the external connection protrusion which concerns on the 1st Embodiment of this invention. Moreover, FIG. 8 is explanatory drawing of the manufacturing process of the semiconductor chip based on the 2nd Embodiment of this invention. Moreover, FIG. 9 is explanatory drawing of the circuit board which mounted the semiconductor chip in which the external connection protrusion concerning the 1st Embodiment of this invention was formed. Further, FIG. 10 is an explanatory diagram of an electronic device including the circuit board shown in FIG.

First, a first embodiment of the present invention will be described. As shown in FIG. 1, the external connection protrusion 20 according to this embodiment is provided on the active surface of the semiconductor chip 10 on which the electrode pads 14 are formed. The external connection protrusion 20 is formed of a protrusion 22 formed so as to protrude on the active surface, and a conductor 24 formed on the electrode pad 14 and straddling the protrusion 22. A protective film 12 is formed on the active surface of the semiconductor chip 10. The protective film 12 also has a function of protecting an active element (not shown) formed in the semiconductor chip 10 and a metal wiring layer, and is formed of a silicon oxide film (SiO ₂ ) or a silicon nitride film (SiN). Yes.

  The protrusion 22 is formed from a thermosetting epoxy resin, and is formed in a region adjacent to the electrode pad 20 to a predetermined height, for example, 30 to 100 μm. Further, the top portion of the projecting body 22 is formed flat in order to ensure electrical connection with a substrate or the like (not shown). In addition to the thermosetting epoxy resin, any material may be used for the protrusion 22 as long as the protrusion 22 can be easily formed on the active surface by a method described later. Further, an inorganic material such as glass may be used.

  The conductor 24 is made of gold (Au), and is formed so as to cover the electrode pad 14 and the top of the protrusion 22 and is continuously formed from the electrode pad 14 to the top of the protrusion 22. Has been. Moreover, the thickness is 3-10 micrometers. In addition to gold, the material of the conductor 24 may be, for example, copper (Cu), nickel (Ni) as long as the conductor 24 can be easily formed on the electrode pad 14 and the protrusion 22 by a method described later. Other metals such as) can also be preferably used.

  Therefore, in the external connection protrusion 20, the conductor 24 is formed on the top of the protrusion 22 formed at a predetermined height, and furthermore, the conductor 24 is electrically connected to the electrode pad 14. By connecting a wiring pattern or the like of a substrate (not shown) to the top of the protrusion 22, the semiconductor chip 10 and the substrate can be electrically connected. Further, since the protrusion 22 can be easily formed at an arbitrary height, an external connection protrusion having an aspect ratio higher than that of the bump according to the prior art, that is, a height 52 larger than the width 50 can be easily obtained. .

  Furthermore, since the protrusion 22 is made of resin, the protrusion 22 can absorb external stress applied to the semiconductor chip 10 and the like. In addition, since the conductor 24 is formed to a thickness of 3 to 10 μm, even when the external connection protrusion 20 has a considerable height, it is possible to suppress the amount of material used for the conductive material 24. . Further, since the protrusion 22 is formed on the insulating protective film 12, no leak current flows directly from the protrusion 22 to the semiconductor chip 10.

  In addition, the formation site | part of the protrusion 22 is not restricted to the area | region adjacent to the electrode pad 14, You may form apart from the electrode pad 14 as needed. In this case, it is only necessary that the conductor 24 is continuously formed from the electrode pad 14 to the top of the protrusion top 22. Further, a part of the protrusion 22 may be formed on the electrode pad 14. In this case, it is preferable that the conductor 24 and the electrode pad 14 be formed leaving a room for ensuring electrical continuity. Further, the top portion of the protrusion 22 may be formed in another shape such as a gentle convex surface as long as electrical connection with the substrate or the like can be ensured.

  In addition, the conductor 24 is formed only in the range from the electrode pad 14 to the top of the protrusion 22 in FIG. 1, but as shown in FIG. 2, the conductor 24 is formed on the entire surface of the protrusion 22. It may be formed. Moreover, although the protrusion 22 shall have the side surface inclined in FIG. 1, as shown in FIG. 3, it is good also as a perpendicular | vertical thing.

  Here, a method of forming the external connection protrusion according to the first embodiment will be described with reference to FIG.

  As shown in FIG. 7A, in the semiconductor wafer 16 in which the formation of the protective film 12 and the electrode pad 14 has been completed, first, as shown in FIG. And then heat. By heating, the resin forming the protrusion 22 is cured and stuck to the part. In addition, when the protrusion 22 is formed of a photocurable resin, it is cured by irradiating ultraviolet rays or the like. Moreover, when the protrusion 22 is formed of an inorganic material, the protrusion 22 is pasted with an adhesive. Next, a barrier film and a plating base film are formed on the entire surface of the semiconductor wafer 16.

  Next, as shown in FIG. 7C, a photoresist is applied to the entire active surface of the semiconductor wafer 16 to form a photoresist film 40. Subsequently, the photoresist film 40 is exposed and developed, and the conductor The opening 42 is formed by removing the portion of the film forming the film. It is desirable that the thickness of the photoresist film 40 be equal to or greater than the height of the external connection protrusion to be formed.

  Next, as shown in FIG. 7D, the conductor 24 is formed in the opening 42 by plating. The thickness of the conductor 24 is preferably 3 to 10 μm as described above.

  Next, as shown in FIG. 7E, the photoresist film 40 is peeled off. The peeling method may be either dry or wet. Next, using the conductor 24 as a mask, unnecessary portions of the barrier film and the plating base film are etched.

  The external connection protrusion 20 is formed by each process described above. The above steps are all wafer processes, and the processing for each semiconductor chip can be performed at once. The dicing of the semiconductor wafer 16 is performed after the above steps are completed.

  Next, a second embodiment of the present invention will be described. As shown in FIG. 4, the external connection protrusion 20 according to this embodiment has a shape in which a bottomed cylindrical portion is upright on the electrode pad 14. Further, the hollow portion 28 is formed in an open state on the tip end side of the bottomed cylindrical portion, and a flange-like portion 26 that protrudes in the horizontal direction is formed in the opening portion on the tip end side of the bottomed cylindrical portion. Has been. In addition, the height of the external connection protrusion 20 is formed in the range of 30 to 150 μm, and the thickness of the bottomed cylindrical portion and the bowl-shaped portion 26 is in the range of 3 to 10 μm. The external connection protrusion 20 is entirely formed of gold.

  Therefore, in the external connection protrusion 20, the semiconductor chip 10 can be electrically connected to the substrate or the like by connecting a wiring pattern or the like of the substrate (not shown) to the distal end portion including the flange portion 26. Further, since the hollow portion 28 is formed, an external connection projection having a high aspect ratio can be easily obtained as compared with the amount of gold used for forming the external connection projection 20. Furthermore, since the planar area near the tip of the external connection protrusion 20 is increased by providing the hook-shaped portion 26, the area of the portion contributing to the connection with the substrate or the like is increased, and the connection with the substrate or the like is increased. To increase the reliability.

  In addition to gold, other materials such as copper, nickel, and aluminum (Al) are preferably used as the material of the external connection protrusion 20 as long as it can be easily formed on the electrode pad 14 by a method described later. be able to. Further, the height of the external connection protrusion 20 and the thickness of the bottomed cylindrical portion and the flange-like portion 26 are not limited to those described above, and may be appropriately changed as necessary.

  Here, a method of forming the external connection protrusion according to the second embodiment will be described with reference to FIG.

  As shown in FIG. 8A, in the semiconductor wafer 16 in which the formation of the protective film 12 and the electrode pad 14 has been completed, first, as shown in FIG. 8B, a photoresist is applied to the entire active surface of the semiconductor wafer 16. The photoresist film 40 is formed by coating, and then the photoresist film 40 is exposed and developed, and the film of the portion where the external connection protrusion is formed is removed to form the opening 42. Next, a metal film to be a plating base is formed on the inner surface of the opening by sputtering. Next, the surface other than the inner surface of the opening, that is, the metal film on the upper surface of the resist is removed by a reverse sputtering process or a polishing process, leaving only the metal film on the inner surface of the opening. The thickness of the photoresist film 40 is desirably matched with the height of the bottomed cylindrical portion to be formed.

  Next, as shown in FIG. 8C, the external connection protrusion 20 is formed in the opening 42 by plating. At this time, gold is deposited even on the photoresist film 40 around the opening 42 so that the hook-shaped portion 26 is formed. The thickness of the external connection protrusion 20 is preferably 3 to 10 μm as described above.

  Next, as shown in FIG. 8D, the photoresist film 40 is peeled off. The peeling method may be either dry or wet.

  The external connection protrusion 20 is formed by each process described above. The above steps are all wafer processes, and the processing for each semiconductor chip can be performed at once. The dicing of the semiconductor wafer 16 is performed after the above steps are completed.

  Furthermore, a third embodiment of the present invention will be described. In this embodiment, a plurality of external connection protrusions according to the first embodiment are integrated and provided. That is, as shown in FIG. 5, the external connection protrusion 20 forms a protrusion 22 adjacent to and parallel to the four electrode pads 14, and further, the conductor 24 is connected to the electrode pad 12 every four electrode pads. It is formed so as to straddle the top and the protrusion 22. Other configurations are the same as those described in the first embodiment.

  Therefore, in this embodiment, the same effect as that of the first embodiment can be obtained, and one projecting body is provided for a plurality of electrode pads. Simplification can be achieved.

  In FIG. 5, one protrusion 22 is provided for four electrode pads 14. However, the number of electrode pads 14 is not limited to this, and any number of electrode pads 14 may be used as long as it is two or more. There may be. Further, the shape of the protrusion 22 and the formation range of the conductor 24 may be the same as those shown in FIG. 2 or FIG. 3, as in the first embodiment. The external connection protrusions 20 are formed by the same method as in the first embodiment except that the plurality of protrusions 22 are integrally formed.

  Further, a fourth embodiment of the present invention will be described. In this embodiment, all the external connection protrusions formed on one semiconductor chip are integrated. That is, as shown in FIG. 6, the external connection protrusion 20 has a frame-like protrusion 30 disposed so as to be adjacent to the inside of each electrode pad 14 of the semiconductor chip 10, and the conductor 24 is provided for each electrode pad. It is formed so as to straddle over the electrode pad 12 and the frame-like protrusion 30. Other configurations are the same as those described in the first embodiment.

  Therefore, in this embodiment, the same operational effects as in the first embodiment are obtained, and one protrusion is provided for all electrode pads formed on one semiconductor chip. In addition, the process of forming the external connection protrusion can be simplified.

  Note that the frame-like projecting body 30 may be formed in a shape in which an opening is not provided at the center thereof, that is, as a whole in one plate-like body. Further, the shape of the protrusion 22 and the formation range of the conductor 24 may be the same as those shown in FIG. 2 or FIG. 3, as in the first embodiment. The external connection protrusions 20 are formed by the same method as in the first embodiment except that all the protrusions 22 are integrally formed.

  Furthermore, FIG. 9 shows an example using the semiconductor chip on which the external connection protrusion described above is formed. That is, FIG. 9 shows the circuit board 100 on which the semiconductor chip 110 on which the external connection protrusion is formed according to the embodiment of the present invention is mounted. As the circuit board 100, an organic substrate such as a glass epoxy substrate is generally used. On the circuit board 100, for example, a bonding portion made of copper is formed so as to form a desired circuit. Then, the electrical connection between the bonding part and the external electrode of the semiconductor chip 110 is achieved by mechanical connection.

  In addition, the semiconductor chip 110 can reduce the mounting area to an area for mounting with a bare chip, and if the circuit board 100 is used for an electronic device, the electric device itself can be downsized. In addition, in the same area, more mounting space can be secured and higher functionality can be achieved.

  A notebook personal computer 120 is shown in FIG. 10 as an electronic apparatus including the circuit board 100.

As described above, in the embodiment of the present invention, the external connection protrusion having a small and high aspect ratio can be formed, and therefore, the external connection protrusion particularly suitable for a small semiconductor chip can be provided. In addition, since one external connection protrusion is formed for a plurality of electrode pads, the process of forming the external connection protrusion can be simplified.

It is sectional drawing of the external connection protrusion which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the modification of the external connection protrusion which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the modification of the external connection protrusion which concerns on the 1st Embodiment of this invention. It is sectional drawing of the external connection protrusion which concerns on the 2nd Embodiment of this invention. It is a perspective view of the external connection protrusion which concerns on the 3rd Embodiment of this invention. It is a top view of the external connection protrusion which concerns on the 4th Embodiment of this invention. It is explanatory drawing of the manufacturing process of the external connection protrusion which concerns on the 1st Embodiment of this invention. It is explanatory drawing of the manufacturing process of the semiconductor chip which concerns on the 2nd Embodiment of this invention. It is explanatory drawing of the circuit board which mounted the semiconductor chip in which the external connection protrusion which concerns on the 1st Embodiment of this invention was formed. It is explanatory drawing of the electronic device provided with the circuit board shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Semiconductor chip 12 Protective film 14 Electrode pad 16 Semiconductor wafer 20 External connection protrusion 22 Projection body 24 Conductor 26 Gutter-shaped part 28 Hollow part 30 Frame-shaped projection body 40 Photoresist film 42 Opening part 50 Width 52 Height 100 Circuit board 110 Semiconductor device 120 notebook personal computer

Claims (11)

  In the external connection protrusion formed on the active element forming surface of the semiconductor chip, a protrusion formed in the vicinity of the electrode of the semiconductor chip, and a conductive formed continuously on the electrode and the protrusion And an external connection protrusion having at least a body.   The external connection protrusion according to claim 1, wherein the conductor is formed so as to cover a top portion of the protrusion.   The external connection protrusion according to claim 1, wherein a top portion of the protrusion is formed flat.   The projecting body is formed in parallel to the electrode arrangement and in the vicinity of the electrode, and the conductor is formed for each of the electrodes. External connection protrusion according to crab.   5. The external connection protrusion according to claim 4, wherein the protrusion is formed in a frame shape in a region surrounded by the electrode on the active element forming surface.   The external connection protrusion according to claim 1, wherein the protrusion is made of resin.   An external connection protrusion formed on an active element formation surface of a semiconductor chip, wherein the external connection protrusion is formed in a bottomed cylindrical shape on an electrode of the semiconductor chip.   A semiconductor chip comprising the external connection protrusions according to claim 1.   A circuit board on which the semiconductor chip according to claim 8 is mounted.   An electronic apparatus comprising the circuit board according to claim 9.   In the method of forming external connection protrusions on a semiconductor wafer, a step of adhering a protrusion in the vicinity of an electrode formed on the semiconductor wafer, and forming a conductor on the electrode and the protrusion by plating. A method of forming an external connection protrusion.

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