JP2009111196A - Wiring board with solder bump, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring board with a solder bump, which ensures a proper and solid connection between an electrode on a semiconductor element and a soldering pad via a solder bump, and to provide a method for manufacturing the same. <P>SOLUTION: The wiring board with the solder bump has a mounting part A on an insulating substrate 1 having the mounting part A on its top surface in which a semiconductor element 101 is mounted, wherein many soldering pads 3 to which an electrode 102 on the semiconductor element 101 is electrically connected are arranged and formed in a lattice pattern, and a solder bump 4 for connection with the electrode on the semiconductor element 101 is welded to each of the soldering pads 3. At the periphery of the mounting part A on the top surface of the insulating substrate 1, a dummy pad 4 is provided, and a dummy solder 7A is welded to the dummy pad 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wiring board with solder bumps for mounting a semiconductor element and a method for manufacturing the same.

  In recent years, a wiring board used for mounting a semiconductor element such as a semiconductor integrated circuit element is formed by alternately laminating a plurality of wiring conductor layers made of a copper base material and an insulating substrate made of a glass base material and a thermosetting resin. And a build-up board in which a plurality of insulating layers made of a thermosetting resin and filler and a wiring conductor layer made of a copper plating layer are laminated on an insulating board. Then, on the upper surface of the wiring board such as a printed board or a build-up board, a solder joint pad arranged in a lattice shape and a central portion of the solder joint pad are exposed to connect the electrodes of the semiconductor element. A solder resist layer is deposited and solder bumps are formed on the solder bonding pads exposed from the solder resist layer to bond the semiconductor element and the solder bonding pads.

  In such a wiring board with solder bumps, the semiconductor element is placed on the upper surface of the wiring board so that each electrode abuts on the corresponding solder bump, and these are mounted on a heating device such as an electric furnace. The semiconductor element is mounted on the wiring board by heating the solder bump to melt the solder bump and bonding the solder bump and the electrode of the semiconductor element.

  Note that such a wiring board with solder bumps is formed on the surface of an insulating substrate having a plurality of wiring conductors inside and on the surface, and a plurality of circular solder bonding pads arranged in a grid and connected to the wiring conductor. A solder resist layer having an opening that exposes the central portion of the solder bonding pad is applied, and then a solder mask is provided on each solder bonding pad using a printing mask having a bump forming opening at a position corresponding to each solder bonding pad. A solder paste composed of flux and solder powder is applied and printed in an amount corresponding to the solder bumps using a conventionally known screen printing method, and this is heated to melt the solder powder in the solder paste and onto the solder joint pad. It is manufactured by forming solder bumps.

  However, according to the conventional method for manufacturing a wiring board with solder bumps, when the solder paste is printed and applied onto each solder bonding pad, the outermost periphery (particularly the corner) of the solder bonding pads arranged in a grid and arranged. There is a tendency that the amount of solder paste applied to the solder bonding pads is smaller than the amount of solder on the inner solder bumps. Therefore, when the electrode of the semiconductor element and the solder bonding pad are bonded via the solder bump, the solder amount of the outermost solder bump is insufficient, and the strength of the solder bump becomes weak. There is a problem that it becomes impossible to firmly bond the solder bonding pad to the solder bump via the solder bump.

Therefore, in Patent Document 1, a large number of solder bonding pads to which electrodes of semiconductor elements are connected are formed in an array on the upper surface of an insulating substrate having wiring conductors, and the central portion of the solder bonding pads is exposed. A wiring board on which a solder resist layer having openings is deposited, bump forming openings arranged in a grid and arranged at positions corresponding to the solder bonding pads, and the outside of the arrangement of the bump forming openings And a step of preparing a printing mask having dummy openings formed in the same shape and the same arrangement interval as the bump forming openings, and printing on the solder bonding pads by using the printing mask. A step of printing and applying a dummy solder paste on the solder resist layer on the outside of the solder paste for bump formation and the solder bonding pads The solder paste for bump formation and the solder in the dummy solder paste are heated and melted to form solder bumps joined to the solder joint pads, and on the solder resist layer outside the solder joint pads. A method of manufacturing a wiring board with solder bumps has been proposed in which a solder ball forming step and a solder ball removing step are sequentially performed.
JP 2004-179363 A

  However, according to the method of manufacturing a wiring board with solder bumps proposed in Patent Document 1, when soldering the solder in the dummy solder paste printed and applied onto the solder resist layer outside the solder bonding pad array, Since the molten solder ball does not get wet with the solder resist layer, it is easy to move on the solder resist layer. Therefore, when the arrangement pitch of the solder bonding pads becomes narrow, for example, 200 μm or less, the solder ball melted on the solder resist layer Even if they move slightly due to the effects of vibration, impact, wind pressure, etc. that are received during the manufacturing process, they will contact and fuse with the adjacent solder bumps, resulting in the size of some solder bumps being different from those of other solder bumps. The size of the semiconductor element may become extremely large, or adjacent solder bumps may fuse together and cause an electrical short circuit. There is a problem that a situation can not be correctly and firmly connected via the solder bumps and the electrode and the solder bonding pads occurs.

  The present invention has been devised in view of such conventional problems, and the purpose thereof is to form solder bumps of uniform size on the solder joint pads arranged in a grid and without being short-circuited with each other, Accordingly, it is an object of the present invention to provide a wiring board with solder bumps and a method for manufacturing the same which can normally and firmly connect the electrodes of the semiconductor element and the solder bonding pads via the solder bumps.

  In the wiring board with solder bumps of the present invention, a large number of solder bonding pads in which electrodes of the semiconductor element are electrically connected to the mounting part of the insulating substrate having a mounting part on which the semiconductor element is mounted on the upper surface are in a lattice shape. And a wiring board with solder bumps formed by welding solder bumps connected to the electrodes of the semiconductor element to each of the solder bonding pads, and arranged around the mounting portion on the upper surface of the insulating substrate. A dummy pad is provided, and a dummy solder is welded to the dummy pad.

  The method for manufacturing a wiring board with solder bumps according to the present invention includes a mounting portion in which a large number of solder bonding pads to which electrodes of a semiconductor element are electrically connected are arranged in a grid and arranged on the upper surface. Insulating substrate in which dummy pads are formed around the mounting portion, bump forming openings arranged in a grid and arranged at positions corresponding to the solder bonding pads, and the outside of the arrangement of the bump forming openings And a step of preparing a printing mask having dummy openings formed in the same shape and the same arrangement interval as the bump forming openings, and printing on the solder bonding pads by using the printing mask. A step of printing and applying a solder paste for forming a bump and a dummy solder paste on the dummy pad; A step of forming a solder bump welded to the solder joint pad and forming a dummy solder welded on the dummy pad sequentially by heating and melting the solder in the paste; It is.

  Furthermore, another method for manufacturing a wiring board with solder bumps according to the present invention includes an insulating substrate having a mounting portion in which a large number of solder bonding pads to which electrodes of a semiconductor element are electrically connected are arranged in an array on the upper surface. And the bump forming openings arranged in a grid and arranged at positions corresponding to the respective solder bonding pads, and the bump forming openings having the same shape and the same arrangement interval outside the arrangement of the bump forming openings. And a step of preparing a printing mask having a dummy opening formed in step B, a solder paste for forming bumps on each solder joint pad by printing using the printing mask, and the insulation around the mounting portion A step of printing and applying a dummy solder paste on the substrate, and heating and melting the solder paste for bump formation and the solder in the dummy solder paste, In the method for manufacturing a wiring board with solder bumps, the process of forming solder bumps welded to the mating pad and forming solder balls on the insulating substrate around the mounting portion and the step of removing the solder balls are sequentially performed. The insulating substrate has a recess in which the solder ball is placed at a position where the solder ball is formed.

  According to the wiring board with solder bumps of the present invention, dummy pads are provided around the mounting portion on the upper surface of the insulating substrate in which a large number of solder bonding pads to which the electrodes of the semiconductor element are electrically connected are arranged in a lattice pattern. Since the dummy solder is welded to the dummy pad, the dummy solder is restrained by the dummy pad at the time of melting and does not move. Therefore, the solder bump welded to the solder bonding pad formed on the mounting portion and the dummy solder welded to the dummy pad do not come into contact and fuse at the time of melting, and the size of the solder bump is uniform. As a result, the electrodes of the semiconductor element and the solder bonding pads can be normally and firmly connected via the solder bumps having a uniform size.

  According to the method for manufacturing a wiring board with solder bumps of the present invention, the upper surface has a mounting portion in which a large number of solder bonding pads to which electrodes of semiconductor elements are electrically connected are arranged in a grid pattern. The insulating substrate having dummy pads formed in the periphery of the mounting portion, the bump forming openings arranged at positions corresponding to the solder bonding pads, and the outside of the arrangement of the bump forming openings. A bump is formed on each solder joint pad by preparing a printing mask having a dummy opening formed in the same shape and the same arrangement interval as the bump forming opening, and then printing using this print mask. The solder paste and the dummy solder paste are printed on the dummy pad, and then the bump forming solder paste and the solder in the dummy solder paste are applied. Since the solder bumps are formed by soldering to the solder bonding pads and the dummy solder is formed on the dummy pads, the dummy solder is restrained by the dummy pads during the heat melting. Does not move. Therefore, the solder bump welded to the solder bonding pad formed on the mounting portion and the dummy solder welded to the dummy pad do not come into contact with each other at the time of melting, and the size of the solder bump is uniform. Thus, it is possible to provide a wiring board with solder bumps capable of normally and firmly connecting the electrodes of the semiconductor element and the solder bonding pads via the solder bumps.

  Furthermore, according to another method for manufacturing a wiring board with solder bumps of the present invention, the upper surface has a mounting portion in which a large number of solder bonding pads to which electrodes of semiconductor elements are electrically connected are arranged in a grid pattern. The same shape and the same shape as the bump forming openings on the outside of the insulating substrate, the bump forming openings arranged in a grid and arranged at positions corresponding to the solder bonding pads, and the bump forming openings A printing mask having dummy openings formed at array intervals is prepared, and then printing is performed using the printing mask, whereby a solder paste for bump formation and an insulating substrate around the mounting portion are formed on each solder bonding pad. A dummy solder paste is printed and applied on the top, and then the solder paste for bump formation and the solder in the dummy solder paste are heated and melted and welded to the solder joint pads. In a method for manufacturing a wiring board with solder bumps, in which solder bumps are formed, solder balls are formed on an insulating substrate around a mounting portion, and then the solder balls are removed, the insulating substrate is placed at a position where the solder balls are formed. Since the solder ball has a recess in which the solder ball is seated, the solder ball formed by melting the solder in the dummy solder paste is seated in the recess and is subjected to vibration, impact, wind pressure, etc. It does n’t move. Therefore, the solder bumps welded to the solder bonding pads formed on the mounting portion and the solder balls formed on the insulating substrate around the mounting portion do not come into contact and fuse at the time of melting. Accordingly, it is possible to provide a wiring board with solder bumps that can be uniformly and firmly connected to the electrodes of the semiconductor element and the solder bonding pads via the solder bumps.

  Next, an example of the wiring board with solder bumps of the present invention will be described in detail with reference to FIG. 1 and FIG. FIG. 1 is a cross-sectional view showing an embodiment of a wiring board with solder bumps according to the present invention, and FIG. 2 is a top view of the wiring board with solder bumps shown in FIG. In these drawings, 1 is an insulating substrate, 2 is a wiring conductor, 3 is a solder bonding pad, 4 is a dummy pad, 5 is a solder resist layer, 6 is a solder bump, and 7A is a dummy solder. The wiring board with solder bumps of the invention is configured.

  In the wiring board with solder bumps of this embodiment, two insulating layers 1b made of thermosetting resin are laminated on the upper and lower surfaces of insulating layer 1a made by impregnating glass fabric with thermosetting resin. 1 and a solder resist layer 5 is laminated on the outermost insulating layer 1b. Further, a mounting portion A on which the semiconductor element 101 is mounted is formed at the center of the upper surface of the insulating substrate 1, and the solder bonding pad 3 to which the electrode 102 of the semiconductor element 101 is electrically connected is mounted on the mounting portion A. Is formed. Further, dummy pads 4 are formed around the mounting portion A on the upper surface of the insulating substrate 1. In addition, external connection pads 8 that are electrically connected to the external electric circuit board are formed on the lower surface of the insulating substrate 1, and corresponding solder bonding pads 3 and external connection pads are respectively provided from the upper surface to the lower surface of the insulating substrate 1. Wiring conductors 2 are electrically connected to each other. Solder bumps 6 are welded to the solder bonding pads 3, and dummy solders 7 </ b> A are welded to the dummy pads 4.

  The insulating layer 1a is a core member in the wiring board with solder bumps of the present embodiment, and is formed by impregnating a thermosetting resin such as epoxy resin or bismaleimide triazine resin into a glass fabric in which glass fiber bundles are woven vertically and horizontally, for example. . The insulating layer 1a has a thickness of about 0.3 to 1.5 mm, for example, and has a plurality of through holes 9 having a diameter of about 0.1 to 1 mm from the upper surface to the lower surface. A part of the wiring conductor 2 is attached to the upper and lower surfaces and the inner surface of each through-hole 9, and the upper and lower wiring conductors 2 are electrically connected via the through-hole 9.

  Such an insulating layer 1a is manufactured by thermally curing an insulating sheet in which a glass fabric is impregnated with an uncured thermosetting resin, and then drilling the insulating sheet from the upper surface to the lower surface. In addition, the wiring conductor 2 on the upper and lower surfaces of the insulating layer 1a has a copper foil having a thickness of about 3 to 50 μm attached to the entire upper and lower surfaces of the insulating sheet for the insulating layer 1a, and the copper foil is etched after the sheet is cured. By doing so, a predetermined pattern is formed. The wiring conductor 2 on the inner surface of the through hole 9 is provided with a copper plating film having a thickness of about 3 to 50 μm by an electroless plating method and an electrolytic plating method on the inner surface of the through hole 9 after the through hole 9 is provided in the insulating layer 1a. Formed by precipitation.

  Furthermore, the insulating layer 1 a is filled with a hole filling resin 10 made of a thermosetting resin such as an epoxy resin or a bismaleimide triazine resin in the through hole 9. The hole-filling resin 10 is for making it possible to form the wiring conductor 2 and each insulating layer 1b immediately above and below the through-hole 9 by closing the through-hole 9, and is an uncured paste-like thermosetting resin Are filled in the through-holes 9 by screen printing, thermally cured, and then the upper and lower surfaces thereof are polished substantially flatly. Two insulating layers 1b are laminated on the upper and lower surfaces of the insulating layer 1a including the hole filling resin 10, respectively.

  Each insulating layer 1b laminated on the upper and lower surfaces of the insulating layer 1a is made of a thermosetting resin such as an epoxy resin or a bismaleimide triazine resin, and each has a thickness of about 20 to 60 μm and has a diameter from the upper surface to the lower surface of each layer. Has a plurality of through holes 11 of about 30 to 100 μm. Each of these insulating layers 1b is for providing an insulating interval for wiring the wiring conductor 2 with high density. A high-density wiring can be three-dimensionally formed by electrically connecting the upper wiring conductor 2 and the lower wiring conductor 2 via the through hole 11. Each of such insulating layers 1b has an insulating film made of an uncured thermosetting resin having a thickness of about 20 to 60 [mu] m attached to the upper and lower surfaces of the insulating layer 1a, thermally cured, and laser-processed through-holes. 11 is perforated, and the next insulating layer 1b is sequentially stacked thereon in the same manner. The wiring conductor 2 deposited in the surface of each insulating layer 1b and in the through hole 11 has a thickness of about 5 to 50 μm in the surface of each insulating layer 1b and in the through hole 11 every time each insulating layer 1b is formed. This copper plating film is formed by depositing it in a predetermined pattern by a pattern forming method such as a known semi-additive method.

  The solder bonding pads 3 formed on the mounting portion A on the upper surface of the insulating substrate 1 are circular with a diameter of about 50 to 100 μm, and a large number of grid-like arrays with a pitch of 100 to 200 μm are formed in the region within the mounting portion A. Has been. Such a solder bonding pad 3 functions as a terminal portion for electrically connecting the electrode 102 of the semiconductor element 101 to the wiring conductor 2, and a part of the wiring conductor 2 formed on the uppermost insulating layer 1b. Is exposed in a circular opening 5 a having a diameter of 50 to 100 μm provided in the solder resist layer 5.

  In addition, the dummy pad 4 formed around the mounting portion A on the upper surface of the insulating substrate 1 is a circle having a diameter of about 50 to 100 μm, and on each side of the mounting portion A outside the array of the solder bonding pads 3. On the other hand, the solder bonding pads 3 are formed in one row with the same size and the same arrangement interval. Such a dummy pad 4 prevents the dummy solder 7A for making the size of the solder bump 6 uniform on the insulating substrate 1 when the solder bump 6 described later is welded to the solder bonding pad 3. A part of the wiring conductor 2 formed on the uppermost insulating layer 1b is placed in a circular opening 5b having a diameter of 50 to 100 μm provided in the solder resist layer 5. It is formed by exposing.

  Further, the external connection pads 8 formed on the lower surface of the insulating substrate 1 are circular having a diameter of about 300 to 500 μm, and a plurality of grid-like arrays having a pitch of 600 to 1000 μm are formed in substantially the entire lower surface of the insulating substrate 1. Has been. The external connection pad 8 functions as a terminal portion for electrically connecting the wiring conductor 2 to the external electric circuit board, and a part of the wiring body 2 formed on the lowermost insulating layer 1b is used as a solder resist layer. 5 is exposed by being exposed in a circular opening 5c having a diameter of 300 to 500 μm.

The solder bump 6 welded to the solder bonding pad 3 is made of, for example, lead-containing solder such as lead-tin alloy or lead-free solder such as tin-silver-copper alloy, and the solder bonding pad 3 and the electrode 102 of the semiconductor element 101. Functions as a connection member for electrically connecting the two. Then, by melting the solder bump 6 in a state where the electrode 102 of the semiconductor element 101 is in contact with the solder bump 6, the solder joint pad 3 and the electrode 102 of the semiconductor element 101 are electrically connected via the solder bump 6. The Rukoto. In this way, by soldering the solder bump 6 to the solder bonding pad 3 in advance, the workability of connecting the semiconductor element 101 to the solder bonding pad 3 becomes extremely good.
Prior to bringing the electrode 102 of the semiconductor element 101 into contact with the solder bump 6, if the upper end portion of the solder bump 6 is pressed and flattened, the electrode 102 of the semiconductor element 101 and the solder bump 6 are brought into contact with each other. Is easy and reliable. Therefore, prior to bringing the electrode 102 of the semiconductor element 101 into contact with the solder bump 6, it is preferable to press and flatten the upper end portion of the solder bump 6.

  Such solder bumps 6 are obtained by applying a solder paste for the solder bumps 6 to each solder bonding pad using a printing mask having bump forming openings arranged in a grid and arranged at positions corresponding to the solder bonding pads 3. The solder in the printed solder paste is heated and melted on the solder bonding pads 3 by printing and coating on the solder paste 3.

  The dummy solder 7 A welded to the dummy pad 4 is made of solder having the same composition as the solder bump 6 and is formed simultaneously with the solder bump 6. The dummy solder 7A functions as a discarded solder for making the size of the solder bump 6 welded to the solder joint pad 3 uniform, and the bump is used as a printing mask for printing a solder paste for the solder bump 6. Dummy openings having the same shape and arrangement interval as the formation openings are formed outside the arrangement of the bump formation openings, and the same solder paste as the solder paste is also applied to the dummy pads 4 through the dummy openings. Is printed and applied as a dummy solder paste, and then the solder in the dummy solder paste is welded onto the dummy pad 4 by heating and melting simultaneously with the solder in the solder paste for the solder bumps 6.

  In this case, since the printing mask for printing the solder paste has dummy openings with substantially the same shape and arrangement interval as the bump forming openings on the outside of the arrangement of the bump forming openings, The dummy pad 4 corresponding to the outermost dummy opening tends to reduce the amount of solder paste applied, but the amount of solder paste applied to each inner solder bonding pad 3 is substantially uniform. Further, since the dummy solder 7A melts on the dummy pad 4, it is restrained by the dummy pad 4 and does not fuse with the adjacent solder bump 6. Therefore, according to the wiring board with solder bumps of the present invention, the size of the solder bumps 6 is uniform, and as a result, the electrodes 102 of the semiconductor element 101 and the solder bonding pads 3 are connected to the solder bumps 6 of uniform size. And can be connected normally and firmly.

  Furthermore, since the amount of solder paste applied tends to be small in the dummy pad 4, the height of the dummy solder 7 </ b> A tends to be lower than the height of the solder bump 6. Thus, when the height of the dummy solder 7A is lower than the height of the solder bump 6, the dummy solder 7A becomes an obstacle when the electrode 102 of the semiconductor element 101 is connected to the solder bonding pad 3 via the solder bump 6. Hateful.

  In the above-described embodiment, the dummy pads 4 have the same size and the same arrangement interval as the solder bonding pads 3. However, as shown in FIG. It may be larger than the bonding pad 3. Alternatively, as shown in FIG. 4 as still another embodiment, a continuous belt-like pattern surrounding the mounting portion A may be used. In these cases, the area to which the dummy solder 7A is welded is increased, and the height of the dummy solder 7A can be further reduced accordingly. Therefore, when the electrode 102 of the semiconductor element 101 is connected to the solder bonding pad 3 via the solder bump 6, the dummy solder 7 </ b> A is not easily disturbed.

  In the above-described three embodiments, the dummy pads 4 are arranged over the entire circumference around the mounting portion A. However, as shown in FIGS. 5 and 6 as still another embodiment, the dummy pads 4 are arranged. May be formed only in a region corresponding to a corner portion of the mounting portion A on the upper surface of the insulating substrate 1. In this case, there is an advantage that it is easy to secure a lead path for the wiring conductor 2 from each solder bonding pad 3.

In the wiring board with solder bumps of the other embodiments shown in FIGS. 3 to 6, the dummy pads 4 are compared with the wiring board with solder bumps of the embodiment shown in FIGS. 1 and 2 described above. The dummy solder 7A is different only in size, shape, arrangement, etc., and the other configurations are the same. Accordingly, the same reference numerals are given to the same functional parts as those of the embodiment shown in FIGS. 1 and 2, and the description of each part is omitted for the sake of brevity.

  Next, a method for manufacturing a wiring board with solder bumps according to the present invention will be described with reference to FIGS. FIG. 7 to FIG. 9 are schematic cross-sectional views for each process for explaining an embodiment of a method for manufacturing a wiring board with solder bumps in the present invention. In these drawings, 1 is an insulating substrate, and 20 is a printing mask. is there.

  First, as shown in FIG. 7, a plurality of solder bonding pads 3 to which the electrodes of the semiconductor element are electrically connected are provided on the upper surface and have a mounting portion A arranged in a grid pattern and the periphery of the mounting portion A on the upper surface. Insulating substrate 1 on which dummy pads 4 are formed, bump forming openings 20a arranged in a grid and arranged at positions corresponding to each solder bonding pad 3, and an array of these bump forming openings 20a. A printing mask 20 having dummy openings 20b formed on the outside with the same shape and the same arrangement interval as the bump forming openings 20a is prepared.

  The insulating substrate 1 is the same as that described in the embodiment of the wiring substrate with solder bumps shown in FIGS. Accordingly, the same portions as those of the insulating substrate 1 shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description of each part is omitted for the sake of brevity.

  The printing mask 20 is made of a stainless plate having a thickness of about 20 to 50 μm, and is formed by providing a bump forming opening 20a and a dummy opening 20b on a stainless plate having a uniform thickness using a photolithography technique or a laser processing technique. It is supported by a frame-shaped metal frame (not shown) with an appropriate tension.

  Next, as shown in FIG. 8, the printing mask 20 is placed on the insulating substrate 1 so that the bump forming opening 20a and the dummy opening 20b are positioned on the corresponding solder bonding pad 3 and dummy pad 4, respectively. The solder paste 6 </ b> P for bump formation and the dummy solder paste 7 </ b> P are printed on each solder bonding pad 3 by screen printing using the printing mask 20.

  At this time, the printing mask 20 has the same shape and the same shape as those of the bump forming openings 20a outside the arrangement of the bump forming openings 20a arranged in a grid and arranged in a position corresponding to each solder bonding pad 3. Since the dummy openings 20b formed at the arrangement interval are provided, the printing mask 20 is used to screen-print the solder paste 6P for forming bumps and the dummy pads 4 on each solder bonding pad 3. When the dummy solder paste 7P is printed and applied to the surface, the amount of coating from the dummy openings 20b provided on the outer side of the arrangement of the bump forming openings 20a of the print mask 20 is reduced, but the solder bonding pads 3 arranged on the inner side thereof. The coating amount from the bump forming opening 20a corresponding to is uniform. Therefore, a uniform amount of solder paste 6P is applied to each solder bonding pad 3.

  Next, as shown in FIGS. 9A and 9B, the insulating substrate 1 in which the solder paste 6P for bump formation is printed on the solder joint pad 3 and the dummy solder paste 7P is printed on the dummy pad 4 is printed. Is passed through a reflow furnace having a peak temperature of 200 to 260 ° C., the solder in the bump forming solder paste 6P and the dummy solder paste 7P is heated and melted to form the solder bump 6 welded to the solder joint pad 3. A dummy solder 7A welded on the dummy pad 4 is formed. At this time, as described above, the bump forming solder paste 6P applied to each solder bonding pad 3 has a uniform coating amount, so that the solder bump 6 having a uniform solder amount is formed on each solder bonding pad 3. can do. Further, since the dummy solder 7A melts on the dummy pad 4, it is restrained by the dummy pad 4 and does not fuse with the adjacent solder bump 6. Therefore, according to the method for manufacturing a wiring board with solder bumps of the present invention, the size of the solder bumps 6 is uniform, and as a result, the electrodes of the semiconductor element and the solder bonding pads 3 are connected to the solder bumps 6 of a uniform size. Thus, it is possible to provide a wiring board with solder bumps that can be normally and firmly connected to each other.

  In addition, since the amount of solder paste 7P applied tends to be small in the dummy pad 4, the height of the dummy solder 7A tends to be lower than the height of the solder bump 6. When the height of the dummy solder 7A is lower than the height of the solder bump 6 as described above, the dummy solder 7A is less likely to become an obstacle when the electrode of the semiconductor element is connected to the solder bonding pad 3 via the solder bump 6. A wiring board with bumps can be provided.

  In the embodiment of the method for manufacturing a wiring board with solder bumps described above, the insulating substrate 1 shown in FIGS. 1 and 2 is used as the insulating substrate 1, but the insulating substrate 1 is shown in FIGS. An insulating substrate 1 may be used. In these cases, as described above, as the printing mask 20, the bump forming openings 20a and the bump forming openings 20a which are arranged in a grid pattern at positions corresponding to the solder bonding pads 3 of the insulating substrate 1 and the bump forming openings 20a. Are formed on the solder joint pads 3 with dummy openings 20b formed in the same shape and with the same spacing as the bump forming openings 20a. A dummy solder paste 7 </ b> P is printed on the pad 4. However, when the insulating substrate 1 shown in FIG. 5 and FIG. 6 is used, the dummy opening 20 a of the printing mask 20 is formed only in the region corresponding to the corner portion of the mounting portion A of the insulating substrate 1, and on the dummy pad 4. Only the dummy solder paste 7P is printed and applied. Then, the solder in the solder paste 6P and the dummy solder paste 7P is heated and melted to form the solder bumps 6 welded to the solder bonding pads 3, and the dummy solder 7A welded to the dummy pads 4 is formed. . Among these, when the insulating substrate 1 shown in FIGS. 3, 4, and 5 is used, the area to which the dummy solder 7 </ b> A is welded is increased, and accordingly, the height of the dummy solder 7 </ b> A is further reduced. can do. Therefore, it is possible to provide a wiring board with solder bumps in which the dummy solder 7A is less likely to become an obstacle when the electrodes of the semiconductor element are connected to the solder bonding pads 3 via the solder bumps 6.

  Furthermore, another embodiment of the method for manufacturing a wiring board with solder bumps of the present invention will be described with reference to FIGS. 10 to 12 are schematic cross-sectional views for explaining another embodiment of the method for manufacturing a wiring board with solder bumps in the present invention. In these figures, 1 is an insulating substrate, and 20 is a printing mask.

  Note that the insulating substrate 1 used in this embodiment example has no dummy pad 4 formed on the insulating substrate 1 shown in FIG. 7, so that a solder described later is provided by an opening 5 b provided in the solder resist layer 5. It is the same except that a recess B on which the ball 7B is seated is formed. The printing mask 20 is the same as that shown in FIG. Therefore, the same parts as those of the insulating substrate 1 and the print mask 20 shown in FIG.

  First, as shown in FIG. 10, a large number of solder bonding pads 3 to which electrodes of semiconductor elements are electrically connected are provided on the upper surface and have a mounting portion A arranged in a grid and arranged around the mounting portion A on the upper surface. Insulating substrate 1 having a recess B on which a solder ball 7B, which will be described later, is placed, bump forming openings 20a arranged in a grid and arranged at positions corresponding to each solder bonding pad 3, and these bump forming openings A printing mask 20 having dummy openings 20b formed in substantially the same shape and the same arrangement as the bump forming openings 20a outside the arrangement of the parts 20a is prepared.

  Next, as shown in FIG. 11, the printing mask 20 is placed on the insulating substrate 1 so that the bump forming opening 20a and the dummy opening 20b are positioned on the corresponding solder bonding pad 3 and the recess B, respectively. The solder paste 6P for bump formation and the dummy solder paste 7P on the concave portions B are printed on the solder joint pads 3 by screen printing using the printing mask 20 while being placed.

  At this time, the printing mask 20 has the same shape and the same shape as those of the bump forming openings 20a outside the arrangement of the bump forming openings 20a arranged in a grid and arranged in a position corresponding to each solder bonding pad 3. Since the dummy openings 20b formed at the arrangement intervals are provided, the printing mask 20 is used to screen-print the dummy paste 20P on the solder bonding pads 3 and the dummy B on the recesses B by screen printing. When the solder paste 7P is printed and applied, the coating amount from the dummy openings 20b provided outside the arrangement of the bump forming openings 20a of the print mask 20 is reduced, but it corresponds to the solder bonding pads 3 arranged on the inside. The applied amount from the bump forming opening 20a is uniform. Therefore, a uniform amount of solder paste 6P is applied to each solder bonding pad 3.

  Next, as shown in FIGS. 12 (a) and 12 (b), the insulating substrate 1 in which the solder paste 6P for bump formation on the solder bonding pad 3 and the dummy solder paste 7P on the concave portion B are printed and applied is peaked. Through a reflow furnace at a temperature of 200 to 260 ° C., the solder in the bump forming solder paste 6P and the dummy solder paste 7P is heated and melted to form the solder bump 6 welded to the solder joint pad 3 and the recess B A solder ball 7B placed on the top is formed. At this time, as described above, the bump forming solder paste 6P applied to each solder bonding pad 3 has a uniform coating amount, so that the solder bump 6 having a uniform solder amount is formed on each solder bonding pad 3. can do. Further, the solder ball 7B formed by melting the solder in the dummy solder paste 7P melts on the concave portion B, so that it does not move at the level of vibration, impact, or wind pressure that is placed on the concave portion B and received during the manufacturing process. As a result, there is no contact fusion with the adjacent solder bump 6. Therefore, according to the method for manufacturing a wiring board with solder bumps of the present embodiment, the size of the solder bumps 6 is uniform, and the electrodes of the semiconductor element and the solder joint pads 3 are connected via the solder bumps 6 of uniform size. Thus, it is possible to provide a wiring board with solder bumps that can be connected normally and firmly.

  Finally, as shown in FIG. 12C, when the solder balls 7B are removed from the recesses B, the wiring board with solder bumps according to the present embodiment is completed. In this case, since there is no extra solder ball 7B on the insulating substrate 1, the solder ball 7B does not interfere with the mounting of the semiconductor element. In this way, in order to remove the solder balls 7B from the recesses B, the insulating substrate 1 on which the solder bumps 6 and the solder balls 7B are formed is subjected to immersion cleaning or spray cleaning using an alkaline surfactant aqueous solution or the like. At the same time, a method of washing off and removing the solder balls 7B can be employed.

  In the above-described other embodiments, the recess B on which the solder ball 7B is seated is formed by providing the opening 5b in the solder resist layer 5, but the recess B is pressed into the solder resist layer 5. It may be formed by applying. Further, the concave portion B of the insulating substrate 1 and the dummy opening 20b of the printing mask 20 may be provided at the same arrangement interval as the solder bonding pads 3 only in the region corresponding to the corner portion of the mounting portion A on the upper surface of the insulating substrate 1. .

It is a schematic sectional drawing which shows one Embodiment of the wiring board with a solder bump of this invention. It is a top view of the wiring board with a solder bump shown in FIG. It is a top view which shows other embodiment of the wiring board with a solder bump of this invention. It is a top view which shows other embodiment of the wiring board with a solder bump of this invention. It is a top view which shows other embodiment of the wiring board with a solder bump of this invention. It is a top view which shows other embodiment of the wiring board with a solder bump of this invention. It is a schematic sectional drawing for demonstrating one Embodiment of the manufacturing method of the wiring board with a solder bump of this invention. It is a schematic sectional drawing for demonstrating one Embodiment of the manufacturing method of the wiring board with a solder bump of this invention. (A), (b) is a schematic sectional drawing for demonstrating one Embodiment of the manufacturing method of the wiring board with a solder bump of this invention. It is a schematic sectional drawing for demonstrating other embodiment of the manufacturing method of the wiring board with a solder bump of this invention. It is a schematic sectional drawing for demonstrating other embodiment of the manufacturing method of the wiring board with a solder bump of this invention. (A), (b), (c) is a schematic sectional drawing for demonstrating other embodiment of the manufacturing method of the wiring board with a solder bump of this invention.

Explanation of symbols

1: Insulating substrate 3: Solder bonding pad 4: Dummy pad 6: Solder bump 6P: Solder paste for bump formation 7A: Dummy solder 7B: Solder ball 7P: Dummy solder paste 20: Print mask 20a: For bump formation Opening 20b: Dummy opening B: Recess

Claims (13)

  A plurality of solder bonding pads, in which the electrodes of the semiconductor element are electrically connected to the mounting portion of the insulating substrate having a mounting portion on which the semiconductor element is mounted on the upper surface, are arranged in a grid pattern and the solder bonding A wiring board with solder bumps formed by welding solder bumps for connection to the electrodes of the semiconductor elements to each of the pads, wherein dummy pads are provided around the mounting portion on the upper surface of the insulating substrate, and A wiring board with solder bumps, wherein dummy solder is welded to the dummy pads.   The wiring board with solder bumps according to claim 1, wherein the dummy pads are provided outside the array of the solder bonding pads with the same shape and the same arrangement interval as the solder bonding pads.   3. The wiring board with solder bumps according to claim 1, wherein the dummy pad has a larger area than the solder bonding pad.   2. The wiring board with solder bumps according to claim 1, wherein the dummy pads are formed by a plurality of strip patterns of the solder joint pads and corresponding lengths.   5. The wiring board with solder bumps according to claim 1, wherein the dummy pad is formed only in a region corresponding to a corner of the mounting portion on the upper surface of the insulating substrate.   6. The wiring board with solder bumps according to claim 1, wherein a height of the dummy solder is lower than a height of the solder bump.   An insulating substrate having a mounting portion in which a large number of solder bonding pads to which electrodes of a semiconductor element are electrically connected are arranged on a top surface and arranged in a grid, and dummy pads are formed around the mounting portion on the top surface; The bump forming openings arranged in a grid and arranged at positions corresponding to the solder bonding pads, and outside the arrangement of the bump forming openings, have the same shape and the same arrangement interval as the bump forming openings. A step of preparing a printed mask having a dummy opening formed, and a solder paste for forming a bump on each solder joint pad and a dummy on the dummy pad by printing using the print mask. A step of printing and applying a solder paste, and heat-melting the solder in the bump forming solder paste and the dummy solder paste, and Method for producing a dummy sequential solder bumped wiring board and performing the step of forming solder on the welded dummy pad to form a solder bump that is welded to de.   8. The method of manufacturing a wiring board with solder bumps according to claim 7, wherein the dummy pads are provided outside the array of the solder bonding pads with the same shape and the same arrangement interval as the solder bonding pads.   9. The method of manufacturing a wiring board with solder bumps according to claim 7, wherein the dummy pad has a larger area than the solder bonding pad.   8. The method of manufacturing a wiring board with solder bumps according to claim 7, wherein the dummy pads are formed by a plurality of strip patterns of the solder joint pads and corresponding lengths.   11. The method of manufacturing a wiring board with solder bumps according to claim 7, wherein the dummy pad is formed only in a region corresponding to a corner of the mounting portion on the upper surface of the insulating substrate. .   12. The method for manufacturing a wiring board with solder bumps according to claim 7, wherein the height of the dummy solder is lower than the height of the solder bump. An insulating substrate having a mounting portion in which a large number of solder bonding pads to which electrodes of semiconductor elements are electrically connected are arranged in a lattice shape and arranged on the upper surface, and a lattice arrangement in a position corresponding to each solder bonding pad A step of preparing a formed bump forming opening and a printing mask having dummy openings formed in the same shape and the same arrangement interval as the bump forming openings outside the arrangement of the bump forming openings And a step of printing and applying a solder paste for forming a bump on each solder joint pad and a dummy solder paste on the insulating substrate around the mounting portion by printing using the printing mask, and forming the bump The solder paste for use and the solder paste in the dummy solder paste are heated and melted to form solder bumps welded to the solder joint pads and the tower. In the method of manufacturing a wiring board with solder bumps, in which a step of forming solder balls on the insulating substrate around the portion and a step of removing the solder balls are sequentially performed, the insulating substrate is a position where the solder balls are formed. A method of manufacturing a wiring board with solder bumps, wherein the solder balls have recesses on which the solder balls are placed.

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