JP2008171975A - Semiconductor component mounting structure and mounting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting method and a mounting structure of a semiconductor component, capable of easily mounting a semiconductor component on a circuit board and capable of easily removing it from the circuit board. <P>SOLUTION: A plurality of solder bumps 12 are protruded from the bottom surface of a BGA type semiconductor component 1. A circuit board 3 is provided with a plurality of through holes 31 which have apertures allowing the solder bumps 12 to be inserted and are formed at the same intervals with the solder bumps 12, penetrating in the thickness direction of the circuit board 3. The solder bumps 12 are inserted in the through holes 31 and then heated from the bottom surface side of the circuit board 3, so that the solder bumps 12 are melted and the BGA type semiconductor component 1 is deposited to the circuit board 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor component mounting structure and a mounting method.

Conventionally, various techniques for mounting BGA (Ball Grid Array) type semiconductor components on a circuit board have been proposed.
For example, Patent Document 1 discloses a BGA semiconductor component in which a through hole is provided in an interposer substrate and solder balls are arranged so as to close the through hole. According to this, it is possible to easily correct the soldering failure that occurs when the BGA is mounted on the motherboard etc. by accessing from the opening side of the through hole. Therefore, once the BGA is removed from the motherboard, a new BGA is mounted. A conventional repair process such as reworking is not required, and the time required for correcting a BGA soldering failure can be shortened.
Further, for example, in Patent Document 2, a solder ball protection plate having a through-hole having an opening diameter that is thicker than the radius of the solder ball and thinner than the diameter and having an opening diameter substantially equal to the diameter is disclosed. Is disposed on the solder ball mounting surface of the BGA type electronic component, and after inserting the solder ball into the through hole, the locking hole having a diameter smaller than the diameter of the solder ball is formed on the through hole opening surface of the solder ball protection plate. A BGA type electronic component is disclosed in which a solder ball is firmly held by a solder ball protection plate and is not dropped by an external force by disposing a locking film body formed with the above.
Furthermore, for example, in the mounting structure of the semiconductor component package disclosed in Patent Document 3, a bonding electrode is provided between the semiconductor component package in which the first solder bump protrudes from the bottom surface and the circuit board. An auxiliary substrate having a second solder bump projecting from the back surface of the bonding electrode is interposed so that the first solder bump is welded to the surface of the bonding electrode and the second solder bump is welded to the electrode of the circuit board. It is configured. According to this, it is possible to easily and accurately perform the repair work when the semiconductor component package is replaced with a new one.
JP 2002-340697 A JP 2002-294672 A JP 2002-1000071 A

  However, the conventional semiconductor component mounting method is a form of mounting on a substrate, and since it is not possible to directly access the solder from the back side of the substrate, the semiconductor component cannot be easily attached and detached. There was a problem.

  An object of the present invention is to provide a mounting structure and a mounting method for a semiconductor component in which a semiconductor component can be easily mounted on a circuit board and the semiconductor component can be easily detached from the circuit board.

In order to solve the above-mentioned problem, the invention described in claim 1 is to mount a first semiconductor component having a plurality of lead-containing solder bumps protruding in a lattice shape on a bottom surface on a circuit board, and to use a lead-free solder. In the mounting method of the semiconductor component for mounting the second semiconductor component on the circuit board,
The circuit board has an opening diameter into which the solder bumps can be inserted, is formed at the same interval as the solder bumps, and includes a plurality of through holes penetrating in the thickness direction of the circuit board.
The length of the solder bump in the protruding direction from the first semiconductor component is formed shorter than the length in the thickness direction of the circuit board,
The second semiconductor component is welded to the circuit board using lead-free solder, and then the lead is contained from the bottom surface side of the circuit board at a temperature lower than the melting point of the lead-free solder of the second semiconductor component. The solder bumps are heated to weld the first semiconductor component to the circuit board.

The invention according to claim 2 is a semiconductor component mounting structure in which a semiconductor component having a plurality of solder bumps protruding from the bottom is mounted on a circuit board.
The circuit board has an opening diameter into which the solder bumps can be inserted, is formed at the same interval as the solder bumps, and includes a plurality of through holes penetrating in the thickness direction of the circuit board.
The solder bump is welded in a state of being inserted into the through hole, and the semiconductor component is mounted on the circuit board.

  According to a third aspect of the present invention, in the semiconductor component mounting structure according to the second aspect, the length of the solder bumps protruding from the semiconductor component is shorter than the length of the circuit board in the thickness direction. It is characterized by.

Invention of Claim 4 is the mounting method of the semiconductor component which mounts the semiconductor component by which the several solder bump protruded on the bottom face to a circuit board,
The circuit board has an opening diameter into which the solder bumps can be inserted, is formed at the same interval as the solder bumps, and includes a plurality of through holes penetrating in the thickness direction of the circuit board.
The solder bumps are inserted into the through holes, and then the solder bumps are melted by heating from the bottom side of the circuit board, so that the semiconductor component is welded to the circuit board.

The invention according to claim 5 is the method of mounting a semiconductor component according to claim 4, wherein the solder bump is lead-containing,
The second semiconductor component is welded to the circuit board with lead-free solder, and then the lead-containing solder bumps from the bottom side of the circuit board at a temperature lower than the melting point of the lead-free solder of the second semiconductor component And the semiconductor component is welded to the circuit board.

  According to a sixth aspect of the present invention, in the semiconductor component mounting method according to the fourth or fifth aspect, the length of the solder bump in the protruding direction from the semiconductor component is shorter than the length of the circuit board in the thickness direction. It is formed.

According to the first aspect of the present invention, the first semiconductor component having a plurality of lead-containing solder bumps on the bottom surface protruding in a grid pattern is mounted on the circuit board, and the second semiconductor component is mounted by lead-free solder. In the method for mounting a semiconductor component to be mounted on the circuit board, the circuit board has an opening diameter into which a solder bump can be inserted, and is formed at the same interval as the solder bump and penetrates in the thickness direction of the circuit board. The length of the solder bump in the protruding direction from the first semiconductor component is shorter than the length in the thickness direction of the circuit board. Then, the second semiconductor component is welded to the circuit board with lead-free solder, and then the lead-containing solder bump is formed from the bottom surface side of the circuit board at a temperature lower than the melting point of the lead-free solder of the second semiconductor component. The first semiconductor component is welded to the circuit board by heating.
Therefore, it is possible to directly access the solder from the bottom surface side of the circuit board through the through-hole penetrating the circuit board formed on the circuit board, and the semiconductor component can be easily mounted on the circuit board. In addition, the semiconductor component can be easily removed from the circuit board.
The second semiconductor component is welded to the circuit board with lead-free solder, and then the first semiconductor component is lead at a temperature lower than the melting point of the lead-free solder of the second semiconductor component from the bottom side of the circuit board. Since the solder bumps inside are heated and welded to the circuit board, for example, even after the lead-free solder is applied to the circuit board and the second semiconductor component is welded, a through hole is formed from the bottom side of the circuit board. Then, by melting the solder bump, the first semiconductor component can be welded, and the mounting operation becomes easy.
Furthermore, since the length of the solder bump protruding from the semiconductor component is shorter than the length of the circuit board in the thickness direction, the solder bumps are formed by the solder protruding from the circuit board. Occurrence is prevented, and the semiconductor component can be appropriately mounted on the circuit board.

According to a second aspect of the present invention, in a semiconductor component mounting structure in which a semiconductor component having a plurality of solder bumps protruding from the bottom surface is mounted on a circuit board, the circuit board has an opening that allows solder bumps to be inserted. A plurality of through-holes having a diameter and being formed at the same interval as the solder bumps and penetrating in the thickness direction of the circuit board are welded in a state in which the solder bumps are inserted into the through-holes. It is mounted on the circuit board.
Therefore, it is possible to directly access the solder from the bottom surface side of the circuit board through the through-hole penetrating the circuit board formed on the circuit board, and the semiconductor component can be easily mounted on the circuit board. In addition, the semiconductor component can be easily removed from the circuit board.

According to the third aspect of the present invention, the effect of the second aspect of the invention can of course be obtained, and the length of the solder bump in the protruding direction from the semiconductor component is in the thickness direction of the circuit board. It is shorter than the length.
Therefore, in a state where the solder bumps are inserted into the through holes, the solder bumps do not protrude on the bottom surface side of the circuit board, and a trouble such as a solder bridge being formed by the solder protruding from the circuit board occurs. Thus, the semiconductor component can be appropriately mounted on the circuit board.

According to a fourth aspect of the present invention, in a semiconductor component mounting method for mounting a semiconductor component having a plurality of solder bumps protruding from the bottom surface on a circuit board, the circuit board has an opening diameter into which the solder bump can be inserted. And a plurality of through holes formed at the same interval as the solder bumps and penetrating in the thickness direction of the circuit board. The solder bumps are inserted into the through holes, and then heated from the bottom side of the circuit board. As a result, the solder bump is melted, and the semiconductor component is welded to the circuit board.
Therefore, it is possible to directly access the solder from the bottom surface side of the circuit board through the through-hole penetrating the circuit board formed on the circuit board, and the semiconductor component can be easily mounted on the circuit board. In addition, the semiconductor component can be easily removed from the circuit board.

According to the invention described in claim 5, the effect of the invention described in claim 4 can be obtained. The second semiconductor component is welded to the circuit board with lead-free solder, and then the circuit board From the bottom surface side, the solder bump containing lead is heated and welded to the circuit board at a temperature lower than the melting point of the lead-free solder of the second semiconductor component.
Therefore, for example, even after the lead-free solder is applied to the circuit board and the second semiconductor component is welded, the first semiconductor component is obtained by melting the solder bumps through the through holes from the bottom surface side of the circuit board. Can be welded, and the mounting work becomes easy.

According to the invention described in claim 6, it is needless to say that the effect of the invention described in claim 4 or 5 can be obtained, and the length of the solder bump protruding from the semiconductor component is the thickness direction of the circuit board. It is formed shorter than the length of.
Therefore, in a state where the solder bumps are inserted into the through holes, the solder bumps do not protrude on the bottom surface side of the circuit board, and a trouble such as a solder bridge being formed by the solder protruding from the circuit board occurs. Thus, the semiconductor component can be appropriately mounted on the circuit board.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of a circuit board on which a semiconductor component according to this embodiment is mounted. 2 is a partially enlarged view of a side sectional view taken along line II-II in FIG. FIG. 3 is a partially enlarged view of FIG. Further, FIG. 4 is a side sectional view before the lead-containing BGA type semiconductor component and lead-free semiconductor component are mounted on the circuit board in the partially enlarged view of FIG.

  In the present embodiment, the lead-containing BGA type semiconductor component 1 as the first semiconductor component and the lead-free semiconductor component 2 as the second semiconductor component are mounted on the same circuit board 3 and welded. A structure and method for mounting semiconductor components on the circuit board 3 will be described.

Here, the lead-free semiconductor component 2 refers to a semiconductor component that is welded to the circuit board 3 by lead-free solder that does not use lead.
Specifically, the lead-free semiconductor component 2 is mounted on the circuit board 3 by being welded onto the circuit board 3 with, for example, lead-free cream solder 4 applied on the circuit board 3.
On the other hand, a lead-containing semiconductor component refers to a semiconductor component that is welded to the circuit board 3 with lead-containing solder.
Specifically, a BGA (Ball Grid Array) type is employed for the lead-containing semiconductor component, and a plurality of solder bumps 12 formed of lead-containing solder are projected in a grid pattern on the bottom surface. And it mounts on the circuit board 3 by welding on the circuit board 3 by this solder bump 12 containing lead.

Since lead-containing solder has a lower melting point than lead-free solder, lead-containing BGA type semiconductor component 1 is mounted at a lower mounting temperature than lead-free semiconductor component 2. Specifically, for example, the melting point of lead-free solder is about 220 ° C., and mounting is realized at a maximum mounting temperature of 260 ° C. On the other hand, the melting point of lead-containing solder (for example, eutectic solder) is 183 ° C., and mounting is performed at a maximum mounting temperature of 240 ° C.
Therefore, conventionally, it has been difficult to mount a semiconductor component on the same circuit board 3 using both lead-containing solder and lead-free solder, but in this embodiment, mounting is performed using lead-containing solder. A solder bump 12 is provided on the bottom surface of the semiconductor component to be made into a BGA type semiconductor component 1, and a through hole 31 penetrating the circuit board 3 is provided in a region of the circuit board 3 on which the semiconductor component 1 is mounted. The solder bumps 12 are directly accessible from the bottom side of the circuit board 3. Therefore, after the lead-free semiconductor component 2 is mounted on the circuit board 3 using lead-free solder, the BGA type semiconductor component 1 having the solder bumps 12 made of lead-containing solder is mounted, and solder is applied from the bottom surface of the circuit board 3. The bumps 12 can be dissolved and mounted, and mounting with lead-free solder and lead-containing solder on the same circuit board 3 can be easily performed.

  First, the mounting structure of the lead-containing BGA type semiconductor component 1 and the lead-free semiconductor component 2 on the circuit board 3 in this embodiment will be described.

As shown in FIGS. 1 to 4, for example, the lead-containing BGA type semiconductor component 1 includes a housing 11 having an electronic component or the like (not shown) therein, and a plurality of protrusions protruding in a lattice shape on the bottom surface of the housing 11. And solder bumps 12. The solder bumps 12 are formed, for example, in a cylindrical shape, inserted into through holes 31 formed in the circuit board 3, and welded to lands 32 provided in the through holes 31. Play a role. For the solder bump 12, for example, solder called eutectic solder obtained by synthesizing tin (Sn) and lead (Pb) at a ratio of 38% to 62% is used.
The length of the solder bump 12 in the protruding direction from the semiconductor component is shorter than the length of the circuit board 3 in the thickness direction. Therefore, as shown in FIG. 3, the solder bump 12 does not protrude to the bottom surface side of the circuit board 3 in a state of being inserted into the through hole 31. For example, the length of the solder bump 12 in the protruding direction from the BGA type semiconductor component 1 is formed to be about three quarters of the length of the circuit board 3 in the thickness direction.

The lead-free semiconductor component 2 includes, for example, a housing 21 that includes an electronic component (not shown) and the like, and terminals 22 that serve as electrodes provided on the side surfaces of the housing 21.
Examples of the lead-free solder used when the lead-free semiconductor component 2 is mounted on the circuit board 3 include Sn—Ag—Cu, Sn—Ag—Bi—In, and Sn—Zn—Bi. It is cream solder 4 of composition. The cream solder 4 is applied onto lands (not shown) formed on the circuit board 3 and melted by heating, whereby the terminals 22 of the lead-free semiconductor components 2 placed thereon and the circuit board 3 These lands are welded and electrically connected.

The circuit board 3 is made of, for example, a material such as a glass epoxy material, and is mounted with electronic components such as the semiconductor components 1 and 2 described above. For example, as shown in FIGS. 2 and 3, the circuit board 3 partially includes a plurality of through holes 31 penetrating in the thickness direction of the circuit board 3. Hereinafter, the region where the through hole 31 is provided in the circuit board 3 will be described as region A, and the region where the through hole 31 is not provided will be described as region B.
In the region A where the through hole 31 is provided, the lead-containing BGA type semiconductor component 1 is placed. The through holes 31 have an opening diameter into which the solder bumps 12 of the lead-containing BGA type semiconductor component 1 can be inserted, and are formed at the same intervals as the solder bumps 12. Each through hole 31 is formed with a land 32 as an electrode insulated from each other. The land 32 is made of a conductive material, and for example, copper foil (Cu) is used.
The lead-free semiconductor component 2 is placed in the region B where the through hole 31 is not provided. In this region B, although not shown, lands as electrodes are formed, and the cream solder 4 is applied on the lands.

  The solder bumps 12 projecting from the bottom surface of the lead-containing BGA type semiconductor component 1 and the through holes 31 formed in the region A of the circuit board 3 are formed in a lattice shape at the same interval. That is, for example, when the solder bumps 12 are provided at intervals of 1.0 mm, the through holes 31 are also provided at the same interval of 1.0 mm as the interval of the solder bumps 12. In this case, for example, the land 32 is formed with an opening diameter of about 0.6 mm, and the solder bump 12 inserted into the through hole 31 in which the land 32 is formed is formed with a diameter of about 0.5 mm.

  Next, a method of mounting the lead-containing BGA type semiconductor component 1 and the lead-free semiconductor component 2 on the circuit board 3 will be described.

First, the cream solder 4 is applied on lands (not shown) formed in the region B on the surface of the circuit board 3. The cream solder 4 is applied by, for example, a metal mask method.
Next, the lead-free semiconductor component 2 is placed in the region B of the circuit board 3. At this time, the arrangement is performed so that the terminals 22 of the lead-free semiconductor component 2 are positioned on the cream solder 4.
Then, the cream solder 4 is heated and melted by a reflow soldering method or the like, and the terminals 22 of the lead-free semiconductor component 2 are welded to the land portions of the circuit board 3. The lead-free semiconductor component 2 is mounted, for example, by preheating at 170 ° C. for 60 to 120 seconds and heating at a maximum temperature of 260 ° C. for 5 to 10 seconds.
Through the above steps, the soldering of the lead-free semiconductor component 2 is completed.

  When the soldering of the lead-free semiconductor component 2 is completed, the lead-containing BGA type semiconductor component 1 is subsequently placed in the region A on the surface of the circuit board 3 where the through holes 31 are formed. At this time, the solder bumps 12 protruding from the bottom surface of the housing 11 of the lead-containing BGA type semiconductor component 1 are arranged so as to be inserted into the through holes 31 provided in the region A of the circuit board 3. .

  Next, the solder bump 12 of the lead-containing BGA type semiconductor component 1 inserted into the through hole 31 is directly accessed from the bottom surface side of the circuit board 3 by a soldering iron or the like, and the cream solder 4 as a lead-free solder is used. The lead-containing solder bumps 12 are melted by heating at a temperature lower than the melting point of the lead and higher than the melting point of the lead-containing solder bumps 12, so that the lead-containing BGA type semiconductor component 1 is landed on the circuit board 3. Weld in 32 parts. The lead-containing BGA type semiconductor component 1 is mounted by, for example, preheating at 150 ° C. for 60 to 120 seconds, heating at a maximum temperature of 240 ° C. for 5 to 10 seconds, or the like.

  As described above, the lead-free semiconductor component 2 and the lead-containing BGA type semiconductor component 1 are respectively welded on the same circuit board 3 and electrically connected to the circuit board 3, and the mounting operation is completed. .

According to the semiconductor component mounting method in the present embodiment described above, a plurality of lead-containing solder bumps 12 project in a grid pattern on the bottom surface of the lead-containing BGA type semiconductor component 1, and the lead-free semiconductor component 2 is The circuit board 3 is mounted on the circuit board 3 with the lead-free cream solder 4. The circuit board 3 has an opening diameter into which the solder bumps 12 can be inserted and is formed at the same interval as the solder bumps 12. A plurality of through holes 31 penetrating in the direction are provided, and the length of the solder bump 12 in the protruding direction from the lead-containing BGA type semiconductor component 1 is shorter than the length of the circuit board 3 in the thickness direction. Then, the lead-free semiconductor component 2 is welded to the circuit board 3 with the lead-free cream solder 4, and then the temperature lower than the melting point of the lead-free cream solder 4 of the lead-free semiconductor component 2 from the bottom surface side of the circuit board 3. The lead-containing solder bump 12 is heated to weld the lead-containing BGA type semiconductor component 1 to the circuit board 3.
Therefore, it is possible to directly access the solder from the bottom surface side of the circuit board 3 through the through hole 31 penetrating the circuit board 3 formed in the circuit board 3, and the semiconductor component is placed on the circuit board 3. It can be easily mounted and the semiconductor component can be easily detached from the circuit board 3.
Further, the lead-free semiconductor component 2 is welded to the circuit board 3 by the lead-free cream solder 4, and then the lead-containing BGA type semiconductor component 1 is lead-free of the lead-free semiconductor component 2 from the bottom side of the circuit board 3. The solder bumps 12 containing lead are heated and welded to the circuit board 3 at a temperature lower than the melting point of the cream solder 4. Therefore, for example, even after the lead-free cream solder 4 is applied to the circuit board 3 and the lead-free semiconductor component 2 is welded, the solder bumps 12 are melted from the bottom surface side of the circuit board 3 through the through holes. Thus, the lead-containing BGA type semiconductor component 1 can be welded, and the mounting operation becomes easy.
Furthermore, since the length of the solder bump 12 in the protruding direction from the BGA type semiconductor component 1 is shorter than the length in the thickness direction of the circuit board 3, a solder bridge is formed by the solder protruding from the circuit board 3. Thus, it is possible to appropriately mount the semiconductor component on the circuit board 3 by preventing the occurrence of a malfunction such as that.

In the present invention, various improvements and design changes may be made without departing from the spirit of the invention.
For example, the shape of the solder bump 12 is not limited to a cylindrical shape, and a spherical shape, a conical shape, or the like can be appropriately employed.
Further, even when the cream solder is applied to the portion where the BGA type semiconductor component 1 containing lead is mounted on the circuit board 3, the lead-containing solder bumps 12 are inserted into the through holes 31. Since the lead-containing semiconductor component 1 can be welded to the circuit board 3 from the back side of the circuit board 3, the lead-free cream solder is compared with the case where the lead-containing semiconductor component 1 is welded to the surface of the circuit board. 4 can be reduced.
Further, for example, the description has been given using the example in which the solder bumps 12 are provided on the semiconductor component 1 in a lattice shape, but a configuration in which the solder bumps 12 are provided only in the peripheral portion of the semiconductor component 1 may be used.
Further, for example, the lead-free semiconductor component 2 is not limited to the case of being soldered by the cream solder 4 and may be, for example, a BGA type similarly to the lead-containing semiconductor component 1.
In mass production, a copper foil or the like may be embedded to eliminate the through hole of the circuit board 3, and the circuit board can be used as a normal circuit board without changing the pattern.
The solder bumps of the BGA type semiconductor component may be lead-free.

It is a top view of the circuit board by which the semiconductor component in this embodiment was mounted. It is the elements on larger scale of the side sectional view in the II-II line of Drawing 1. FIG. 3 is a partially enlarged view of FIG. 2. FIG. 4 is a side cross-sectional view of a partially enlarged view of FIG. 3 before a lead-containing BGA type semiconductor component and a lead-free semiconductor component are mounted on a circuit board.

Explanation of symbols

1 BGA type semiconductor parts (first semiconductor parts)
12 Solder bumps 2 Lead-free semiconductor parts (second semiconductor parts)
3 Circuit board 31 Through hole 4 Cream solder (lead-free solder)

Claims (6)

Mounting a first semiconductor component having a plurality of lead-containing solder bumps projecting in a grid pattern on the bottom surface on a circuit board, and mounting the second semiconductor component on the circuit board by lead-free solder In
The circuit board has an opening diameter into which the solder bumps can be inserted, is formed at the same interval as the solder bumps, and includes a plurality of through holes penetrating in the thickness direction of the circuit board.
The length of the solder bump in the protruding direction from the first semiconductor component is formed shorter than the length in the thickness direction of the circuit board,
The second semiconductor component is welded to the circuit board with lead-free solder, and then the lead-containing solder is formed from the bottom surface side of the circuit board at a temperature lower than the melting point of the lead-free solder of the second semiconductor component. A method for mounting a semiconductor component, comprising: heating a bump to weld the first semiconductor component to the circuit board. In a semiconductor component mounting structure in which a semiconductor component having a plurality of solder bumps on the bottom surface is mounted on a circuit board,
The circuit board has an opening diameter into which the solder bumps can be inserted, is formed at the same interval as the solder bumps, and includes a plurality of through holes penetrating in the thickness direction of the circuit board.
A mounting structure of a semiconductor component, wherein the solder bump is welded in a state inserted in the through hole, and the semiconductor component is mounted on the circuit board.   3. The semiconductor component mounting structure according to claim 2, wherein the length of the solder bump in the protruding direction from the semiconductor component is shorter than the length in the thickness direction of the circuit board. In a method for mounting a semiconductor component in which a semiconductor component having a plurality of solder bumps on the bottom surface is mounted on a circuit board,
The circuit board has an opening diameter into which the solder bumps can be inserted, is formed at the same interval as the solder bumps, and includes a plurality of through holes penetrating in the thickness direction of the circuit board.
The solder bump is inserted into the through hole, and then the solder bump is melted by heating from the bottom side of the circuit board, so that the semiconductor component is welded to the circuit board. Implementation method. The solder bump contains lead,
The second semiconductor component is welded to the circuit board with lead-free solder, and then the lead-containing solder bumps from the bottom side of the circuit board at a temperature lower than the melting point of the lead-free solder of the second semiconductor component The method of mounting a semiconductor component according to claim 4, wherein the semiconductor component is welded to the circuit board by heating the substrate.   6. The method of mounting a semiconductor component according to claim 4, wherein the length of the solder bump in the protruding direction from the semiconductor component is shorter than the length in the thickness direction of the circuit board.

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