JP2011103383A - Semiconductor device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To narrow a pitch of a conductor pattern in a method of manufacturing a semiconductor device. <P>SOLUTION: The method of manufacturing a semiconductor device includes the steps of: depositing powder 23 of a first metal to at least one of the conductor pattern 22 of a circuit board 20 and a bump electrode 31 of the semiconductor device 30; substituting at least a part of the powder 23 with a second metal having a melting point lower than that of the first metal; and, after the substituting, melting the powder 23 into a connection medium 35 by heating and connecting the conductor pattern 22 to the bump electrode 31 with the connection medium 35. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof.

  In electronic devices such as computer systems, flip-chip mounting is used as a form for mounting semiconductor elements on a circuit board. Flip chip mounting uses gold bumps to electrically and mechanically connect circuit boards and semiconductor elements, and since the mounting area is small and the wiring routing distance is short, the speed of electronic equipment is increased and the integration is large. It is advantageous to make.

  FIG. 1 is an enlarged plan view of a circuit board used for flip chip mounting.

  The circuit board 1 includes a plurality of conductor patterns 4 made of copper on a resin base material 2, and these conductor patterns 4 are exposed from the window 3 a of the solder resist layer 3.

  The conductor pattern 4 is provided with a wide portion 4a for forming a solder reservoir described later.

  2A and 2B are cross-sectional views for explaining flip-chip mounting using the circuit board 1. FIG.

  In mounting, first, as shown in FIG. 2A, a solder layer 7 is formed by printing a solder paste on the surface of the conductor pattern 4.

  Next, when the solder layer 7 is reflowed and melted, the melted solder aggregates in the wide portion 4a of the conductor pattern 4 due to its surface tension, and a solder reservoir 7a is formed in the wide portion 4a.

  Next, as shown in FIG. 2B, the gold bump 9 of the semiconductor element 8 is brought into contact with the solder reservoir 7a while the semiconductor element 8 is heated by a bonding heating head (not shown). As a result, the solder layer 7 is heated and melted via the gold bump 9, and a sufficient amount of solder in the solder reservoir 7 a crawls up to the side surface of the gold bump 9.

  Thereafter, when the solder layer 7 is cooled and solidified, the semiconductor element 8 and the circuit board 1 are electrically and mechanically connected via the solder layer 7, and a flip chip mounting structure using the gold bumps 9 is obtained.

  According to this, since the solder layer 7 is melted and softened by the heat of the gold bump 9, the load applied to the gold bump 7 during mounting can be reduced. Therefore, the risk of the gold bumps 7 sliding on the surface of the conductor pattern 4 can be reduced, and the conductor pattern 4 and the gold bumps 7 can be aligned with good accuracy.

  Furthermore, by forming the solder reservoir 7a, a sufficient amount of solder gathers on the side surface of the gold bump 9, and the connection reliability between the gold bump 9 and the conductor pattern 4 can be improved.

  However, in order to form the solder reservoir 7a, it is necessary to form the wide portion 4a in the conductor pattern 4 as shown in FIG. 1, and the wide portion 4a reduces the interval W between the adjacent conductor patterns 4. Therefore, this method is not suitable for narrowing the pitch of the conductor pattern 4.

  It is also conceivable to increase the connection reliability between the conductor pattern 4 and the gold bump 9 by increasing the thickness of the solder layer 7 by supplying a large amount of solder onto the conductor pattern 4 without forming the wide portion 4a. . However, this causes another problem that the melted solder layer 7 spreads on the resin base material 2 and the adjacent conductor patterns 4 are electrically short-circuited by the solder.

JP 2000-077471 JP 2006-320943 A JP-A-4-192596

  An object of the semiconductor device and the manufacturing method thereof is to reduce the pitch of a conductor pattern.

  According to one aspect of the following disclosure, a step of attaching a first metal powder to at least one of a conductor pattern of a circuit board and a protruding electrode of a semiconductor element, and at least part of the powder includes the first Substitution with a second metal having a melting point lower than that of the first metal, and after the substitution, the powder is melted by heating to form a connection medium, and the conductor pattern and the protruding electrode are connected by the connection medium. A method for manufacturing a semiconductor device is provided.

  According to another aspect of the disclosure, a circuit board having a conductor pattern formed on a surface, a semiconductor element having a protruding electrode above a partial region of the conductor pattern, and a conductor pattern formed on the conductor pattern. A semiconductor device having a connection medium for connecting the protruding electrode and the conductor pattern, wherein the thickness of the conductor pattern in the partial region is larger than the thickness of the conductor pattern outside the partial region. Provided.

  According to the following disclosure, at least a part of the powder is replaced with a second metal having a melting point lower than that of the first metal, and the replaced powder is used as a connection medium. Connect the electrodes. Since the powder functions like a solder reservoir, it is not necessary to form a wide portion for forming the solder reservoir in the conductor pattern, and it is possible to reduce the pitch of the conductor pattern.

  Moreover, by substituting the second metal having a melting point lower than that of the first metal in this way, the powder after replacement can be easily melted by heating, and the connecting medium formed by melting the powder The protruding electrode 31 and the conductor pattern can be easily connected.

FIG. 1 is an enlarged plan view of a circuit board used for flip chip mounting according to a conventional example. 2A and 2B are cross-sectional views for explaining flip-chip mounting according to a conventional example. FIG. 3A is a perspective view (part 1) of the semiconductor device according to the first embodiment during manufacture, and FIG. 3B is a cross-sectional view (part 1). FIG. 4A is a perspective view (part 2) in the middle of manufacturing the semiconductor device according to the first embodiment, and FIG. 4B is a sectional view thereof (part 2). FIG. 5A is a perspective view (part 3) of the semiconductor device according to the first embodiment during manufacture, and FIG. 5B is a cross-sectional view (part 3). FIG. 6A is a perspective view (part 4) of the semiconductor device according to the first embodiment during manufacture, and FIG. 6B is a cross-sectional view (part 4). FIG. 7A is a perspective view (No. 5) in the course of manufacturing the semiconductor device according to the first embodiment, and FIG. 7B is a sectional view thereof (No. 4). FIG. 8A is a perspective view (part 6) of the semiconductor device according to the first embodiment during manufacture, and FIG. 8B is a cross-sectional view (part 5). FIG. 9A is a perspective view (No. 7) in the course of manufacturing the semiconductor device according to the first embodiment, and FIG. 9B is a sectional view thereof (No. 6). FIG. 10A is a perspective view (part 8) of the semiconductor device according to the first embodiment during manufacture, and FIG. 10B is a cross-sectional view (part 7). FIG. 11 is a cross-sectional view of the semiconductor device along the longitudinal direction of the conductor pattern in the first embodiment. FIG. 12 is a view drawn based on a cross-sectional photograph of the semiconductor device according to the first embodiment. FIG. 13A is a perspective view (part 1) in the course of manufacturing the semiconductor device according to the second embodiment, and FIG. 13B is a cross-sectional view thereof (part 1). FIG. 14A is a perspective view (part 2) in the middle of manufacturing the semiconductor device according to the second embodiment, and FIG. 14B is a cross-sectional view thereof (part 2). FIG. 15A is a perspective view (part 3) of the semiconductor device according to the second embodiment during manufacture, and FIG. 15B is a cross-sectional view (part 3). FIG. 16A is a perspective view (part 4) of the semiconductor device according to the second embodiment during manufacture, and FIG. 16B is a cross-sectional view thereof (part 4). FIG. 17A is a perspective view (part 5) of the semiconductor device according to the second embodiment during manufacture, and FIG. 17B is a cross-sectional view (part 5) thereof. FIG. 18A is a perspective view (part 6) of the semiconductor device according to the second embodiment during manufacture, and FIG. 18B is a cross-sectional view (part 6). FIG. 19A is a perspective view (No. 7) in the course of manufacturing the semiconductor device according to the second embodiment, and FIG. 19B is a sectional view thereof (No. 7). FIG. 20A is a perspective view (part 8) of the semiconductor device according to the second embodiment during manufacture, and FIG. 20B is a cross-sectional view (part 8). FIG. 21A is a perspective view (No. 9) in the middle of manufacturing the semiconductor device according to the second embodiment, and FIG. 21B is a sectional view (No. 9). FIG. 22 is a view drawn based on a cross-sectional photograph of the semiconductor device according to the second embodiment.

  Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings.

(First embodiment)
3 to 10 are a perspective view and a cross-sectional view in the middle of manufacturing the semiconductor device according to the present embodiment.

  In order to manufacture this semiconductor device, first, a circuit board 20 as shown in FIGS. 3A and 3B is prepared.

  The circuit board 20 includes a plurality of conductor patterns 22 formed by patterning a copper film or the like on the surface, and these conductor patterns 22 are exposed from the windows 21a of the solder resist layer 21.

  The interval between the conductor patterns 22 is not particularly limited, but is 50 μm in this embodiment. The total number of conductor patterns 22 is 400, for example.

  Furthermore, the thickness of the circuit board 20 is about 0.35 mm, and BT resin can be used as the material thereof.

  The cross-sectional view shown in FIG. 3B is an enlarged cross-sectional view of two adjacent conductor patterns 22 among the cross-sections taken along the line II in the perspective view of FIG. The same applies to each of the sectional views described later.

  Next, as shown in FIGS. 4A and 4B, copper powder having an average particle diameter of 7 μm is applied as a powder 23 in a window 21a which is a mounting area of a semiconductor element. The powder 23 may have an arbitrary three-dimensional shape such as a spherical shape, an irregular shape, or a flake shape.

  Furthermore, the powder 23 is not limited to copper powder. As the metal material of the powder 23, any one of copper, copper alloy, indium, nickel, iron, manganese, zirconium, titanium, aluminum, chromium, and zinc can be adopted.

  Subsequently, as shown in FIGS. 5A and 5B, the ultrasonic head 25 is pressed against the powder 23. Then, an ultrasonic wave having a vibration direction in a direction D parallel to the main surface of the circuit board 20 is generated, and the ultrasonic wave is applied to the head 25. The frequency of the ultrasonic wave is about 100 kHz, and the application time of the ultrasonic wave is about 0.5 seconds.

  As a result, the powder 23 rubs against each conductor pattern 22, and in a partial region R corresponding to the contact surface of the head 25, the oxide film on the surface of the powder 23 and each conductor pattern 22 is broken and these are metal. Come to join.

  At this time, in order to obtain good metal bonding, it is preferable to employ the same material as the metal contained in each conductor pattern 22 as the metal material of the powder 23. For example, when the conductor pattern 22 contains copper, it is preferable to employ copper as the metal material of the powder 23.

  Further, by making the direction D of ultrasonic vibration parallel to the main surface of the circuit board 20, the powder 23 vibrates so as to rub on the surface of the conductor pattern 22, and the powder 23 and the conductor pattern 22 are made of metal. It becomes easy to make it join.

  Since the surface of the circuit board 20 where the conductor pattern 22 is not formed has a difference in height from the surface of the conductor pattern 22, the powder 23 does not adhere strongly.

  Thereafter, as shown in FIGS. 6A and 6B, the powder 23 adhering to an unnecessary portion of the circuit board 20 is removed using an organic solvent such as IPA (isopropyl alcohol). Thereby, only the powder 23 in which metal bonding is formed with each conductor pattern 22 remains only on the conductor pattern 22, and the powder is selectively selectively only in a partial region R of each conductor pattern 22. 23 can be attached.

  Thus, in this embodiment, the powder 23 can be left only in a partial region below the contact surface of the ultrasonic head 25 by using the height difference between the circuit board 20 and the conductor pattern 22. It is not necessary to print the powder 23 by a printing method or the like that is difficult to miniaturize.

  Next, as shown in FIGS. 7A and 7B, the circuit board 20 is immersed in a plating solution for substitutional electroless tin plating, so that the copper in the powder 23 has a lower melting point. Replace with tin.

  The plating conditions are not particularly limited. For example, 580MJ manufactured by Ishihara Yakuhin is used as the plating solution, the solution temperature is about 60 ° C., and the treatment time is about 30 minutes. By adopting this condition, it is possible to replace all portions of one powder 23 with tin.

  However, it is not necessary to completely replace the powder 23 with tin as described above, and copper that is not replaced with tin may remain in the vicinity of the center of the powder 23.

  In this plating, since the conductor pattern 22 outside the partial region R is also exposed to the plating solution, the copper on the surface layer of the conductor pattern 22 is also replaced with tin, and the metal layer 27 containing tin is formed.

  Furthermore, the metal after the substitution is not limited to a single tin, and the powder 23 may be substituted with solder obtained by adding silver or bismuth to tin.

  Next, as shown in FIGS. 8A and 8B, a semiconductor element 30 having a plurality of protruding electrodes 31 such as gold bumps is prepared on a circuit forming surface, and this semiconductor element is formed by a flip chip bonder (not shown). While holding 30, each protruding electrode 31 and each conductor pattern 22 are aligned. The outer shape of the semiconductor element 30 is, for example, a square having a side length of about 8.5 mm.

  In addition, as a method of forming each protruding electrode 31, for example, while maintaining the stage temperature of a ball bonder (not shown) at 200 ° C., the end of the gold wire is joined to the circuit formation surface of the semiconductor element 30, and the gold wire There is a way to tear off. In the semiconductor element 30, 400 such protruding electrodes 31 are formed in accordance with the number of conductor patterns 22.

  Next, as shown in FIGS. 9A and 9B, the heat of the flip chip bonder is used to heat and melt the powder 23 via the bump electrodes 31, and the connection made of the melted powder 23 is performed. Each protruding electrode 31 and each conductor pattern 22 are connected by a medium 35. The heating temperature at this time is about 300 ° C., and the heating time is about 3 seconds. The pressing force by the flip chip bonder is about 3 g per one protruding electrode 31.

  At this time, since the powder 23 selectively adhered on each conductor pattern 22 functions like a solder reservoir, a sufficient amount of the connection medium 35 formed by melting the powder 23 on the side surface of the protruding electrode 31. Crawls up. Therefore, when the connection medium 35 is solidified by cooling, the conductor pattern 22 and the protruding electrode 31 are reliably connected by the connection medium 35.

  7A and 7B, the metal layer 27 is formed by replacing not only the powder 23 but also the surface layer of the lateral conductor pattern 22 in the partial region R with tin, so that tin is contained. It is possible to prevent the molten connection medium 35 from spreading wetly over the entire conductor pattern 22. As a result, most of the connection medium 35 can be scooped up on the side surface of the protruding electrode 31, and the conductive pattern 22 and the protruding electrode 31 can be reliably connected by the thick connection medium 35.

  Further, since the molten tin stays only on the conductive pattern 22 having good wettability and does not spread between the adjacent conductive patterns 22, it is possible to reduce the risk that the conductive patterns 22 are electrically short-circuited by the connection medium 35. .

  Thereafter, as shown in FIGS. 10A and 10B, after the thermosetting underfill resin 37 is filled between the circuit board 20 and the semiconductor element 30, the temperature is maintained at about 150 ° C. The underfill resin 37 is heated for about 2 hours in the illustrated thermostat to be thermally cured.

  Thus, the basic structure of the semiconductor device according to this embodiment is completed.

  FIG. 11 is a cross-sectional view of the semiconductor device along the longitudinal direction of the conductor pattern 22.

  As shown in FIG. 11, in this semiconductor device, the thickness T1 of the conductor pattern 22 in the partial region R is larger than the thickness T2 outside the partial region R.

  As shown in FIG. 7A, the powder 23 is selectively attached to the conductor pattern 22 in the partial region R, and the powder 23 is used as a mask during substitutional electroless plating. This is because the copper in the conductor pattern 22 is not easily replaced with tin, and the unsubstituted copper tends to remain.

  According to the above-described embodiment, as described with reference to FIGS. 7A and 7B, the substitutional electroless tin plating is used to selectively apply to the partial region R of the conductor pattern 22. The adhered powder 23 was replaced with tin having a lower melting point.

  Since the powder 23 after replacement functions like a solder reservoir that increases the connection reliability between the conductor pattern 22 and the protruding electrode 31, it is not necessary to form a wide portion for forming a solder reservoir in the conductor pattern 22. The narrowing of the conductor pattern 22 is not hindered by the wide portion.

  Accordingly, it is possible to reduce the pitch of the conductor pattern 22 in accordance with the increase in the number of pins and the pitch of the protruding electrode 31 while ensuring the connection strength between the protruding electrode 31 and the conductor pattern 22.

  Further, since the powder 23 is replaced with tin having a melting point lower than that of copper in the powder 23, the replaced powder 23 can be easily melted by heating, and the connection formed by melting the powder 23. The protruding electrode 31 and the conductor pattern 22 can be easily connected by the medium 35.

  It is also conceivable that tin powder is used as the powder 23 from the beginning without performing substitutional electroless tin plating on the powder 23 and the conductor pattern 22. However, in this case, the connection medium 35 (see FIGS. 9A and 9B) formed by melting the powder 23 wets and spreads on the conductor pattern 22 with copper exposed on the surface, and thus covers the protruding electrode 31. There is a possibility that the connection medium 35 becomes thin and the connection reliability between the bump electrode 31 and the conductor pattern 22 is lowered.

  Therefore, from the viewpoint of improving the connection reliability, it is preferable to use copper powder as the powder 23 as in this embodiment, and to perform electrolytic tin plating on the powder 23 and the conductor pattern 22.

  Furthermore, in the present embodiment, unlike the conventional example, since the surface tension of the molten solder is not used when forming the solder reservoir, the powder 23 can be attached to the conductor pattern 22 having an arbitrary planar shape.

  Moreover, in the step of attaching the powder 23 to the conductor pattern 22 (FIGS. 6A and 6B) and the step of replacing the powder 23 with tin (FIGS. 7A and 7B), a circuit is used. There is no need to heat the substrate 20. Therefore, it is possible to prevent the circuit board 20 from warping due to heat as in the case of forming a solder reservoir by reflowing solder as in the conventional example, and the conductor pattern 22 and the protruding electrode 31 are displaced due to warpage. Can be prevented.

  FIG. 12 is a diagram drawn based on a cross-sectional photograph of the semiconductor device according to the present embodiment.

  As shown in FIG. 12, in this semiconductor device, the side surface of the protruding electrode 31 is covered with a sufficient amount of connection medium 35. The connection medium 35 is not cracked, and the protruding electrode 31 and the conductor pattern 22 are securely connected by the connection medium 35. From this, it was confirmed that the connection reliability between the protruding electrode 31 and the conductor pattern 22 is improved by using the powder 23.

(Second Embodiment)
In the first embodiment, as described with reference to FIGS. 6A and 6B, the powder 23 is attached to the conductor pattern 22.

  On the other hand, in this embodiment, the powder 23 is attached to the protruding electrode of the semiconductor element as follows.

  13 to 21 are a perspective view and a cross-sectional view in the middle of manufacturing the semiconductor device according to the present embodiment.

  In these drawings, the same elements as those described in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted below.

  In order to manufacture this semiconductor device, first, as shown in FIGS. 13A and 13B, powder 23 is formed on a plate 40 made of engineering plastic such as epoxy resin, phenol resin, polyester, and polycarbonate. The copper powder is applied and the semiconductor element 30 described in the first embodiment is prepared above the plate 40.

  The metal material of the powder 23 is not limited to copper, and any of copper, copper alloy, indium, nickel, iron, manganese, zirconium, titanium, aluminum, chromium, and zinc can be adopted as the material of the powder 23.

  Next, as shown in FIGS. 14A and 14B, the semiconductor element 30 is lowered toward the plate 40 by a flip chip bonder (not shown), and the protruding electrode 31 is brought into contact with the powder 23.

  In this state, an ultrasonic wave is applied to the protruding electrode 31 from the flip chip bonder, so that the powder 23 is rubbed against the protruding electrode 31 by the ultrasonic wave. As a result, the oxide films on the surfaces of the powder 23 and the protruding electrode 31 are broken, and the powder 23 and the protruding electrode 31 are metal-bonded.

  The application condition of the ultrasonic wave is not particularly limited, but in this embodiment, the frequency of the ultrasonic wave is about 100 kHz and the application time is about 0.5 seconds.

  Here, if the vibration direction of the ultrasonic wave is a direction perpendicular to the main surface of the semiconductor element 30, the protruding electrode 31 may strongly stimulate the circuit forming surface of the semiconductor element 30 by the ultrasonic wave and may destroy the circuit. . Therefore, it is preferable to adopt the ultrasonic vibration direction D in a direction parallel to the main surface of the semiconductor element 30 so that the circuit in the semiconductor element 30 is not easily damaged by the ultrasonic wave.

  Thereafter, when the semiconductor element 30 is separated from the plate 40, the powder 23 can be selectively attached only to the protruding electrodes 31, as shown in FIGS. 15 (a) and 15 (b).

  Subsequently, as shown in FIGS. 16A and 16B, by immersing the semiconductor element 30 in a plating solution for substitutional electroless tin plating, the copper in the powder 23 has a lower melting point. Replace with tin.

  As the plating solution at this time, for example, 580MJ manufactured by Ishihara Yakuhin is used. As the plating conditions, a liquid temperature of about 60 ° C. and a processing time of about 30 minutes are employed. Under this condition, all parts in the powder 23 are replaced with tin.

  However, as described in the first embodiment, copper that is not substituted with tin may remain near the center of the powder 23 without completely replacing the powder 23 with tin.

  Further, the metal after the substitution is not limited to a single tin, and the powder 23 may be substituted with a solder obtained by adding silver or bismuth to tin.

  In this step, only the powder 23 is selectively replaced with tin, and the protruding electrode 31 containing gold is not replaced with tin. In substitutional electroless tin plating, only a metal having a standard electrode potential lower than −0.136 V, which is the standard electrode potential of tin, is replaced with tin, and gold having a standard electrode potential of 1.50 V is This is because it is not replaced with tin.

  Next, as shown in FIGS. 17A and 17B, the same circuit board 20 as described in the first embodiment is prepared. The circuit board 20 includes a solder resist layer 21, and a plurality of conductor patterns 22 are exposed from the window 21 a of the solder resist layer 21.

  Subsequently, as shown in FIGS. 18A and 18B, the circuit board 20 is immersed in a plating solution for substitutional electroless tin plating, and the surface layer of the conductor pattern 22 exposed from the window 21a is replaced with tin. As a result, the metal layer 27 containing tin is formed.

  As the plating conditions at this time, the same conditions as when the powder 23 was replaced with tin in the steps of FIGS. 16 (a) and 16 (b) can be adopted, and 580MJ made by Ishihara Yakuhin was used as the plating solution. Can be used for The liquid temperature is about 60 ° C. and the processing time is about 30 minutes.

  Note that the metal layer 27 may be formed by electrolytic tin plating instead of such substitutional electroless plating.

  Next, as shown in FIGS. 19A and 19B, the semiconductor element 30 is held by a flip chip bonder (not shown), and the alignment between the protruding electrodes 31 and the conductive patterns 22 is performed. Thereafter, the semiconductor element 30 is lowered toward the circuit board 20, and the powder 23 is brought into contact with the surface metal layer 27 of the conductor pattern 22.

  Then, as shown in FIGS. 20A and 20B, using the heat of the flip chip bonder, the powder 23 is heated and melted through the protruding electrodes 31, and the connection made of the melted powder 23 is performed. Each protruding electrode 31 and each conductor pattern 22 are connected by a medium 35. The heating temperature at this time is about 300 ° C., and the heating time is about 3 seconds. The pressing force by the flip chip bonder is about 3 g per one protruding electrode 31.

  In this step, the powder 23 previously attached to each protruding electrode 31 functions like a solder reservoir, and the protruding electrode 31 can be covered with a sufficient amount of connection medium 35 formed by melting the powder 23. it can. Therefore, when the connection medium 35 is solidified by cooling, the conductor pattern 22 and the protruding electrode 31 can be reliably connected by the connection medium 35.

  Further, as shown in FIGS. 18A and 18B, since the metal layer 27 containing tin is formed in advance on the surface layer of the conductor pattern 22, the molten connection medium 35 containing tin becomes the conductor pattern 22. It can prevent it from spreading wetly on top. As a result, the conductor pattern 22 and the protruding electrode 31 can be connected by a sufficient amount of the connection medium 35, and the connection reliability of these can be improved.

  Then, as shown in FIG. 21, after filling the thermosetting underfill resin 37 between the circuit board 20 and the semiconductor element 30, the temperature is maintained in a thermostat (not shown) maintained at about 150 ° C. The underfill resin 37 is heated and cured for about 2 hours.

  Thus, the basic structure of the semiconductor device according to this embodiment is completed.

  According to the above-described embodiment, as described with reference to FIGS. 16A and 16B, the powder 23 attached to the protruding electrode 31 is replaced with tin by using electroless tin plating. .

  Since the powder 23 after replacement functions like a solder reservoir, it is not necessary to form a wide portion for forming the solder reservoir in the conductor pattern 22, and the conductor pattern 23 can be miniaturized and highly integrated by the wide portion. There is no hindrance. As a result, it is possible to promote downsizing of the semiconductor device through miniaturization and high integration of the conductor pattern 23.

  Furthermore, since the powder 23 is replaced with tin having a melting point lower than that of copper in the powder 23, the replaced powder 23 can be easily melted by heating, and the connection formed by melting the powder 23. The protruding electrode 31 and the conductor pattern 22 can be easily connected by the medium 35.

  FIG. 22 is a diagram drawn based on a cross-sectional photograph of the semiconductor device according to the present embodiment.

  As shown in FIG. 22, also in this semiconductor device, the side surface of the protruding electrode 31 is covered with a sufficient amount of the connection medium 35 as in the first embodiment, and the connection medium 35 is cracked. Not. Therefore, also in this embodiment, it has been confirmed that the connection reliability between the protruding electrode 31 and the conductor pattern 22 is improved by the powder 23.

  The following additional notes are disclosed for each embodiment described above.

(Appendix 1) A step of attaching a first metal powder to at least one of a conductor pattern of a circuit board and a protruding electrode of a semiconductor element;
Replacing at least a portion of the powder with a second metal having a melting point lower than that of the first metal;
After the replacement, the step of melting the powder by heating to a connection medium, and connecting the conductor pattern and the protruding electrode by the connection medium;
A method for manufacturing a semiconductor device, comprising:

  (Supplementary note 2) The method of manufacturing a semiconductor device according to supplementary note 1, wherein the step of attaching the powder is performed by selectively attaching the powder to a partial region of the conductor pattern.

  (Appendix 3) The step of attaching the powder is performed by applying the powder to the conductor pattern and applying an ultrasonic wave to the powder on the partial region. The manufacturing method of the semiconductor device as described in 2 ..

  (Additional remark 4) The metal which the said conductor pattern contains as said 1st metal is employ | adopted, The manufacturing method of the semiconductor device of Additional remark 3 characterized by the above-mentioned.

  (Supplementary note 5) In the step of substituting the second metal with the powder, the surface layer of the conductor pattern outside the partial region is also substituted with the second metal. A method for manufacturing a semiconductor device.

  (Supplementary note 6) The method of manufacturing a semiconductor device according to supplementary note 1, wherein the step of attaching the powder is performed by rubbing the powder against the protruding electrode with ultrasonic waves.

  (Additional remark 7) Before connecting the said conductor pattern and the said protruding electrode, the metal layer containing the said 2nd metal is formed in the surface layer of the said conductive pattern, The semiconductor device of Additional remark 6 characterized by the above-mentioned. Production method.

  (Supplementary note 8) The method for manufacturing a semiconductor device according to any one of supplementary notes 1 to 7, wherein the step of replacing the powder with the second metal is performed by substitutional electroless plating.

(Supplementary Note 9) As the first metal, any one of copper, copper alloy, indium, nickel, iron, manganese, zirconium, titanium, aluminum, chromium, and zinc is used.
The method for manufacturing a semiconductor device according to any one of appendices 1 to 8, wherein tin or solder is used as the second metal.

(Appendix 10) A circuit board having a conductor pattern formed on the surface;
A semiconductor element provided with a protruding electrode above a partial region of the conductor pattern;
A connection medium formed on the conductor pattern and connecting the protruding electrode and the conductor pattern;
The semiconductor device, wherein a thickness of the conductor pattern in the partial region is thicker than a thickness of the conductive pattern outside the partial region.

DESCRIPTION OF SYMBOLS 1,20 ... Circuit board, 2 ... Resin base material, 3, 21 ... Solder resist, 4, 22 ... Conductor pattern, 4a ... Wide part, 7 ... Solder layer, 7a ... Solder reservoir, 8, 30 ... Semiconductor element, 9 DESCRIPTION OF SYMBOLS ... Gold bump, 21a ... Window, 23 ... Powder, 25 ... Ultrasonic head, 27 ... Metal layer, 31 ... Projection electrode, 35 ... Connection medium, 37 ... Underfill resin.

Claims (6)

Attaching a first metal powder to at least one of the conductor pattern of the circuit board and the protruding electrode of the semiconductor element;
Replacing at least a portion of the powder with a second metal having a melting point lower than that of the first metal;
After the replacement, the step of melting the powder by heating to a connection medium, and connecting the conductor pattern and the protruding electrode by the connection medium;
A method for manufacturing a semiconductor device, comprising:   The method of manufacturing a semiconductor device according to claim 1, wherein the step of attaching the powder is performed by selectively attaching the powder to a partial region of the conductor pattern.   The step of attaching the powder is performed by applying the powder to the conductor pattern and applying an ultrasonic wave to the powder on the partial region. A method for manufacturing a semiconductor device. 3. The semiconductor device according to claim 2, wherein in the step of replacing the powder with the second metal, the surface layer of the conductor pattern outside the partial region is also replaced with the second metal. Production method.   The method of manufacturing a semiconductor device according to claim 1, wherein the step of attaching the powder is performed by rubbing the powder against the protruding electrode with ultrasonic waves. A circuit board having a conductor pattern formed on the surface;
A semiconductor element provided with a protruding electrode above a partial region of the conductor pattern;
A connection medium formed on the conductor pattern and connecting the protruding electrode and the conductor pattern;
The semiconductor device, wherein a thickness of the conductor pattern in the partial region is thicker than a thickness of the conductive pattern outside the partial region.

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