JP5006252B2 - Wiring board manufacturing method and wiring board - Google Patents

Description

  The present invention relates to a method of manufacturing a wiring board and a wiring board, and particularly includes a wiring board provided with a connection pad having a curved portion, and a process of removing the support after the wiring board is formed on the support. The present invention relates to a manufacturing method and a wiring board.

  For example, as a method of manufacturing a wiring board on which electronic components are mounted, there is a method of obtaining a wiring board by separating a wiring layer from a support after forming a required wiring layer in a state where it can be peeled off on a support. . In Patent Documents 1 and 2, a temporary substrate (support) is formed by forming a copper foil on a resin substrate by bonding only its peripheral edge with an adhesive layer, and a build-up wiring layer is formed thereon. After that, a method is described in which the inner portion of the adhesive layer is cut to separate the copper foil and the build-up wiring layer from the temporary substrate to obtain the wiring substrate.

  In this type of wiring board manufacturing method, since the temporary board functions as a support when the build-up wiring layer is formed, the build-up wiring layer can be reliably and systematically formed. In addition, since the temporary substrate is removed after the build-up wiring layer is formed, it is possible to reduce the thickness of the manufactured wiring substrate and improve the electrical characteristics.

By the way, conventionally, the surface on which the build-up wiring layer of the support is formed is a flat surface, and the surface is not particularly processed. For this reason, a portion (hereinafter referred to as an external connection terminal portion) that becomes a connection terminal exposed to the outside of the metal wiring of the buildup wiring layer is a flat surface because the surface of the temporary substrate is transferred.
JP 2005-236244 A

  However, a wiring board having a flat external connection terminal portion may have a problem in bonding strength when an electronic component is mounted on the wiring board and bonding with a bonding metal (for example, solder) is attempted. For example, when a stress is generated due to a difference in thermal expansion coefficient between the electronic component and the wiring board, the stress is applied to a contact portion between the external connection terminal and the electronic component terminal. For this reason, when the external connection terminal is a flat surface, there is a problem in that the bonding strength of the bonding portion with the terminal of the electronic component may be insufficient and a connection failure may occur.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing a wiring board and a wiring board capable of improving connectivity with electronic components to be mounted.

From the first aspect of the present invention, the above problem is
A method of manufacturing a wiring board on which a semiconductor chip is mounted,
Forming a concave curved surface that is recessed at a position corresponding to the formation position of the connection pad of the wiring board on the surface of the support;
Forming a pad body on the concave curved surface portion of the support;
Forming a wiring member in which a wiring layer and an insulating layer are laminated on the support;
Forming a connection pad having a curved shape protruding from the substrate surface corresponding to the concave curved surface formed on the support by removing the support from the wiring member;
Soldering post-like terminals that serve as external connection terminals of the semiconductor chip to the connection pads;
Forming the wiring member includes forming a via hole in the insulating layer to expose the pad body ;
And a step of forming a wiring layer for electrically connecting the connection pads through the via hole on the insulating layer.

In addition, the above-mentioned problem is from the second viewpoint of the present invention.
A wiring member in which a wiring layer and an insulating layer are laminated;
A connection pad connected to the wiring layer, protruding from the substrate surface and having a curved surface on the surface;
A wiring board having a semiconductor chip,
The connection pad is made of plating ,
The wiring member is formed by laminating the wiring layer made of plating and the insulating layer made of resin,
The connection pad is provided on the outermost insulating layer forming the wiring board surface,
The connection pad includes a curved first surface exposed from the outermost insulating layer surface and protruding from the outermost insulating layer surface, and the first surface embedded in the outermost insulating layer. An opposite second surface,
The second surface and the wiring layer are connected via a via hole provided in the outermost insulating layer ;
This can be solved by a wiring board having a configuration in which post-like terminals serving as external connection terminals of the semiconductor chip are soldered to the connection pads.

  According to the present invention, since the connection pad and the post-shaped terminal are in point contact, solder is interposed between the connection pad and the post-shaped terminal other than the point contact position. Therefore, the contact area of the solder with respect to a connection pad and a post-like terminal can be increased, and the back sign strength of the connection pad and the post-like terminal can be increased.

  Further, the solder interposed between the connection pad and the post-like terminal functions as a kind of cushioning material. For this reason, even if a stress is desired to be applied to the joint position between the connection pad and the post-like terminal, the stress is absorbed by the deformation of the solder, so that the joint reliability between the connection pad and the post-like terminal can be improved. .

Next, the best mode for carrying out the present invention will be described with reference to the drawings.
(Embodiment of the present invention)
1 to 6 are cross-sectional views sequentially showing a method of manufacturing a wiring board according to an embodiment of the present invention. To manufacture a wiring board, first, as shown in FIG. 1A, a pair of copper foils 12 (supports) are prepared. The thickness of the copper foil 12 is, for example, 35 to 100 μm. The copper foil 12 has a wiring formation area A and an outer peripheral part B outside thereof.

  The pair of copper foils 12 are bonded and integrated by an adhesive 11 to form a support 10 (a composite of support). FIG. 1B shows a state in which a pair of copper foils 12 are bonded with an adhesive 11 and a support 10 is formed.

  The arrangement position of the adhesive 11 is set in the outer peripheral portion B. Therefore, in the wiring formation region A excluding the outer peripheral portion B, the pair of copper foils 12 are not bonded and are simply in a state of facing each other. Note that in FIG. 1B, for easy understanding, the thickness of the adhesive 11 is exaggerated from the actual one, and thus the pair of copper foils 12 are illustrated as being separated from each other. However, the actual adhesive 11 is a thin film, and thus the pair of copper foils 12 is in a substantially intimate contact state.

  Next, as illustrated in FIG. 1C, the resist film 16 in which openings 16 </ b> X are provided in required portions (positions corresponding to positions where curved convex connection pads 18 described later are formed) on both sides of the support 10. Form. For example, a dry film can be used as the resist film 16.

  When the resist film 16 is formed on the support 10, the support 10 is put into an etching apparatus. FIG. 2A is a diagram schematically showing a state in which the support 10 is put into the etching apparatus. The support 10 put into the etching apparatus is guided by a conveying roller (not shown) and moves in the apparatus at a speed V in the left direction in the drawing.

  As shown in the figure, a plurality of shower nozzles 19 are arranged above and below the movement position of the support 10 in the etching apparatus. Each shower nozzle 19 is configured to eject an etching solution for etching the copper foil 12.

  The etchant from the shower nozzle 19 is sprayed onto the copper foil 12 through the opening 16X formed in the resist film 16, and thus the copper foil 12 is etched by this etchant. At this time, the etching amount of the copper foil 12 by the etching solution from the shower nozzle 19 is set to be performed within the thickness range of the copper foil 12. The adjustment of the etching amount can be controlled by the conveyance speed of the support 10 in the etching apparatus.

  FIG. 2B shows a state in which the copper foil 12 is etched by the etching apparatus. A large amount of the etchant from the shower nozzle 19 is sprayed to the central portion of the opening 16X, and the spray amount decreases near the outer periphery of the resist film 16, so that the etching amount of the copper foil 12 at the central position of the opening 16X is large. Thus, the etching amount becomes smaller toward the outer periphery. For this reason, the surface shape of the copper foil 12 in the opening 16X after etching is a concave portion having a spherical curved surface (hereinafter, this portion is referred to as a curved concave portion 13). The curved concave portion 13 is formed at a position corresponding to a position where a curved convex connecting pad 18 described later is formed.

  In the present embodiment, the etching method is used to form the curved recess 13 as described above. However, the formation of the curved recess 13 is not limited to the etching method. It is also possible to form by such as.

  When the curved concave portion 13 is formed at a position corresponding to the position where the curved convex connection pad 18 of the copper foil 12 is formed as described above, by electrolytic plating using the copper foil 12 as a plating power feeding layer, FIG. As shown in A), a curved convex connection pad 18 serving as a first wiring layer is formed on the curved concave portion 13. The curved convex connection pad 18 is formed in an opening 16X formed in the resist film 16, and is composed of a pad surface plating layer 25 and a pad body 26.

  The pad surface plating layer 25 is formed of an Au film 25a, a Pd film 25b, and a Ni film 25c, as shown in an enlarged view in FIG. Therefore, in order to form the curved convex connection pad 18, first, the pad surface plating layer 25 is formed by sequentially plating the Au film 25 a, the Pd film 25 b, and the Ni film 25 c, and then on the pad surface plating layer 25. A pad body 26 made of Cu is formed by plating.

  At this time, the curved convex connection pad 18 is formed on the curved concave portion 13 as described above. Further, the shape of the curved concave portion 13 is a concave portion having a spherical curved surface instead of a flat surface as in the prior art. For this reason, as shown in FIG. 5C, a curved surface portion 26a is formed on a portion of the pad body 26 exposed from the surface of the wiring board (specifically, the surface of the first insulating layer 20). The pad surface plating layer 25 is formed on the surface.

  When the curved convex connection pad 18 is thus formed, the resist film 16 is thereafter removed as shown in FIG. The curved convex connection pad 18 functions as the first connection terminal C1 as will be described later.

  Subsequently, as illustrated in FIG. 3C, the first insulating layers 20 that cover the curved convex connection pads 18 and the connection terminals C <b> 1 are respectively formed on the upper and lower surfaces of the support 10. As a material of the first insulating layer 20, an epoxy resin, a polyimide resin, or the like is used. As an example of the formation method of the 1st insulating layer 20, after laminating the resin film on both surfaces of the support 10, respectively, the resin film is pressed (pressed) and cured by heat treatment at a temperature of 130 to 150 ° C. Thus, the first insulating layer 20 can be obtained.

  Next, as shown in FIG. 3D, the first via hole is formed using a laser processing method or the like so that the curved convex connection pads 18 are exposed on the first insulating layers 20 formed on the upper and lower surfaces of the support 10. 20X is formed. The first insulating layer 20 may be formed by patterning a photosensitive resin film by photolithography, or a method of patterning a resin film provided with openings by screen printing may be used.

  Subsequently, as shown in FIG. 3E, copper (Cu) or the like connected to the curved convex connection pad 18 (first wiring layer) 18 via the first via hole 20X on both sides of the support 10 and the like. The second wiring layer 18a made of is formed on the first insulating layer 20, respectively. The second wiring layer 18a is formed by, for example, a semi-additive method.

  More specifically, after forming a Cu seed layer (not shown) in the first via hole 20X and on the first insulating layer 20 by electroless plating or sputtering, an opening corresponding to the second wiring layer 18a is formed. A resist film (not shown) provided with is formed. Next, a Cu layer pattern (not shown) is formed in the opening of the resist film by electrolytic plating using the Cu seed layer as a plating power supply layer.

  Subsequently, after removing the resist film, the Cu wiring layer 18a is obtained by etching the Cu seed layer using the Cu layer pattern as a mask. In addition, as a formation method of the 2nd wiring layer 18a, various wiring formation methods, such as a subtractive method other than the above-mentioned semi-additive method, are employable.

  Next, as shown in FIG. 4A, by repeating the same process as described above, after forming the second insulating layer 20a covering the second wiring layer 18a on the upper and lower surfaces of the support 10, respectively, A second via hole 20Y is formed in the portion of the second insulating layer 20a on the second wiring layer 18a. Further, the third wiring layer 18b connected to the second wiring layer 18a through the second via hole 20Y is formed on the second insulating layer 20a on both sides of the support 10, respectively.

  Further, after forming the third insulating layer 20b covering the third wiring layer 18b on both the upper and lower surfaces of the support 10, the third via hole 20Z is formed in the portion of the third insulating layer 20b on the third wiring layer 18b. Form each one. Further, the fourth wiring layer 18c connected to the third wiring layer 18b through the third via hole 20Z is formed on the third insulating layer 20b on both sides of the support 10, respectively.

  Subsequently, a solder resist film 22 provided with an opening 22X is formed on each of the fourth wiring layers 18c on both sides of the support 10. As a result, the fourth wiring layer 18c exposed in the opening 22X of the solder resist film 22 becomes the second connection terminal C2. If necessary, a contact layer 43 such as a Ni / Au plating layer may be formed on the fourth wiring layer 18c in the opening 22X of the solder resist film 22.

  In this manner, a required build-up wiring layer is formed on the curved convex connection pad 18 (connection terminal C1) on the support 10. In the example described above, four build-up wiring layers (first to fourth wiring layers 18 to 18c) are formed, but an n-layer (n is an integer of 1 or more) may be formed. .

  Next, as shown in FIG. 4B, the portion corresponding to the periphery of the support 10 on which the build-up wiring layer is formed (the portion connected by the adhesive 11) is cut and the outer peripheral portion B is discarded. As described above, the pair of copper foils 12 is in a state where the pair of copper foils 12 are opposed to each other (the wiring formation region A) other than those bonded by the adhesive 11. For this reason, by removing the outer peripheral portion B connected by the adhesive 11, the support 10 can be easily separated at a position where the pair of copper foils 12 face each other as shown in FIG. it can. Thereby, the wiring member 30 which consists of the copper foil 12 and a buildup wiring layer is each obtained.

  Thereafter, as shown in FIG. 5B, the copper foil 12 of the wiring member 30 is selectively removed with respect to the first wiring layer 18 and the first insulating layer 20. For example, the copper foil 12 is selectively applied to the first wiring layer 18 (such as Au) and the first insulating layer 20 by wet etching using a ferric chloride aqueous solution, a cupric chloride aqueous solution, an ammonium persulfate aqueous solution, or the like. It can be removed by etching.

  By removing the copper foil 12, the curved convex connection pad 18 functioning as the first connection terminal C <b> 1 is exposed from the first insulating layer 20. FIG. 5C shows the curved convex connection pad 18 exposed from the first insulating layer 20 in an enlarged manner.

  As shown in the figure, the curved convex connection pad 18 is configured such that a pad surface plating layer 25 is formed on an upper portion of a pad main body 26. Further, the shape of the curved convex connection pad 18 is a shape obtained by transferring the shape of the curved concave portion 13 shown in FIG. Specifically, a curved surface portion 26a is formed on a portion of the pad body 26 exposed from the surface of the wiring board (the surface of the first insulating layer 20), and a pad surface plating layer 25 is formed on the surface of the curved surface portion 26a. It has become.

  Next, solder is printed on the curved convex connection pads 18 exposed from the first insulating layer 20, and the wiring member 30 on which the solder printing has been performed is mounted in a reflow furnace, and a reflow process is performed. Thereby, solder bumps 29 (joining metal) are formed on the curved convex connection pads 18. Through the above various manufacturing steps, the wiring board 1 is manufactured as shown in FIG.

  In the case where the support 10 is a multi-piece substrate, after the step of forming the solder bumps 29 is finished, the wiring member 30 is cut (dicing or the like) in a region corresponding to each wiring substrate 1, Thereby, the process of separating the wiring board 1 into pieces is added.

  FIG. 7 shows a state in which the semiconductor chip 40 is mounted on the wiring board 1 manufactured as described above. In the example shown in the figure, the semiconductor chip 40 has a post-like terminal 40a as an external connection terminal, and the post-like terminal 40a is connected to the curved convex connection pad 18 functioning as the first connection terminal C1.

  In this connected state, the tip of the post-shaped terminal 40 a is in contact with the upper surface of the curved convex connection pad 18, and the post-shaped terminal 40 a and the curved convex connection pad 18 are soldered by solder bumps 29. Furthermore, the underfill resin 41 is filled between the semiconductor chip 40 and the first insulating layer 20. The fourth wiring layer 18c functions as an external connection terminal (second connection terminal C2) when the wiring board 1 is mounted on, for example, a mother board (not shown).

  FIG. 8 is an enlarged view showing the joint position between the post-like terminal 40a and the curved convex connection pad 18. As shown in FIG. The lower end of the post-like terminal 40a is usually a flat surface as shown in the figure. On the other hand, in the wiring board 1 manufactured by the manufacturing method according to the present embodiment, the shape of the curved convex connection pad 18 that contacts the post terminals 40a is not flat but curved.

  Specifically, in the present embodiment, the tip shape of the curved convex connection pad 18 is a convex shape having a spherical curved surface. For this reason, the post-like terminal 40a and the curved convex connection pad 18 come into contact (that is, point contact) only at the point indicated by the arrow P1 in FIG.

  Further, when the post-like terminal 40a and the curved convex connection pad 18 are in point contact at the point P1, the bottom of the post-like terminal 40a and the surface of the curved convex connection pad 18 are formed around the point P1. A separation region (indicated by an arrow P2 in the figure) is formed between them. Then, solder (solder bump 29) enters the separation region indicated by the arrow P2.

  Therefore, the post-shaped terminal 40a and the curved convex connection pad 18 are in direct contact only at the point P1, and the bottom surface of the post-shaped terminal 40a other than the point P1 and the surface of the curved convex connection pad 18 face each other. In the configuration, solder is interposed between the curved convex connection pad 18 and the post terminal 40a. The solder is softer than the material of the curved convex connection pad 18 (copper is the main material) and the post terminal 40a (for example, copper alloy).

  Therefore, when the solder is interposed between the curved convex connection pad 18 and the post-like terminal 40a, the solder functions as a kind of cushioning material. Thereby, even if it is desired to apply a stress to the joint position between the curved convex connection pad 18 and the post-like terminal 40a due to, for example, a difference in thermal expansion coefficient between the wiring board 1 and the semiconductor chip 40, the stress is The solder interposed between the curved convex connection pad 18 and the post terminal 40a is absorbed by deformation.

  Therefore, the mechanical stress generated between the wiring substrate 1 and the semiconductor chip 40 can be reduced, and the bonding reliability between the curved convex connection pad 18 and the post-like terminal 40a can be improved. Further, since the contact area of the solder bump 29 with the curved convex connection pad 18 and the post terminal 40a is increased, the bonding strength between the curved convex connection pad 18 and the post terminal 40a can be increased.

  FIG. 9 shows another mounting structure when the semiconductor chip 40 is mounted on the wiring board 1. That is, in the structure in which the semiconductor chip 40 described above with reference to FIG. 7 is mounted on the wiring board 1, the example in which the semiconductor chip 40 is mounted on the curved convex connection pad 18 that is the first connection terminal C <b> 1 is shown. On the other hand, in the mounting structure shown in FIG. 9, the semiconductor chip 40 is connected to the fourth wiring layer 18c (connection terminal C2) of the wiring board 1 using the ball-shaped terminals 40b, and the wiring board 1 is connected to the mother board (not shown). The curved convex connection pad 18 is used as the connection terminal C1 to be mounted on.

  FIG. 9A shows an example in which solder bumps 29 are provided on the curved convex connection pads 18. FIG. 9B shows an example in which the lead pins 45 are disposed on the curved convex connection pads 18.

  The lead pin 45 includes a head portion 45a joined to the curved convex connection pad 18, and a pin portion 45b extending downward from the head portion 45a. Further, the curved convex connection pad 18 and the head portion 45 a are joined using the solder 46. At this time, since the curved convex connection pad 18 has a curved surface, the back of the joint surface with the solder 46 increases, so that the bonding strength between the lead pin 45 and the curved convex connection pad 18 can be increased. .

  As described above, the curved convex connection pad 18 formed on the wiring substrate 1 is not necessarily limited to the connection with the semiconductor chip 40, and connects the external device such as a mother board and the wiring substrate 1. It can also be used as an external connection terminal. In this case, since the curved convex connection pad 18 itself has already protruded into a spherical shape, the amount of solder bumps 29 to be used can be reduced.

  FIG. 10 shows the wiring board 1 manufactured by a modification of the manufacturing method of the wiring board 1 according to the first embodiment. In the manufacturing method of the wiring board 1 described above, the copper foil 12 is completely removed in the step described with reference to FIG. On the other hand, in the manufacturing method according to the present modification, the copper foil 12 is not completely removed, but the copper foil 12 other than the mounting area of the semiconductor chip 40 is left in a frame shape without being removed. It is a feature.

The frame-shaped copper foil 12 is formed by forming an etching resist material on the copper foil 12 in which only the mounting area of the semiconductor chip 40 is exposed with respect to the wiring member 30 obtained by the process of FIG. Can be obtained by etching the mounting area of the copper foil 12 and then removing the etching resist material. The copper foil 12 formed so as to remain on the outer periphery of the mounting area of the semiconductor chip 40 as described above functions as a stiffener, so that the mechanical strength of the wiring board 1 can be increased.
(First reference example of the present invention)
Next, a method for manufacturing a wiring board according to a first reference example of the present invention will be described with reference to FIGS. 11 and 12, the same reference numerals are given to the components corresponding to those shown in FIGS. 1 to 10, and the description thereof is omitted.

  FIG. 11A shows a state in which a resist film 16 is formed on the support 10 having a configuration in which a pair of copper foils 12 are joined by an adhesive 11. The state shown in FIG. 11A corresponds to the state shown in FIG.

  In the example shown in FIG. 1C, the resist film 16 is simply formed with the opening 16X. On the other hand, the present reference example is characterized in that a ring-shaped pattern 16Y is formed inside the opening 16X.

  The ring-shaped pattern 16Y is formed integrally with the resist film 16, and is formed at the same time when the opening 16X is formed in the resist film 16. In this reference example, the ring-shaped pattern 16Y is used as the pattern formed in the opening 16X. However, the shape of the pattern 16Y is not limited to the ring shape, and may be various shapes. Is possible.

  Thus, the support 10 on which the resist film 16 having the openings 16X and the ring-shaped pattern 16Y formed on the copper foil 12 is fed into an etching apparatus similar to that shown in FIG. Etching is performed on the copper foil 12 exposed from the opening 16X by the etching solution.

  FIG. 11B shows a state in which the etching process for the copper foil 12 has been completed. As described above, the etchant from the shower nozzle 19 is sprayed onto the copper foil 12 through the opening 16X formed in the resist film 16, and thus the copper foil 12 is etched by this etchant.

  At this time, the etching amount of the copper foil 12 is larger at the portion where the amount of the etching solution is sprayed, and the etching amount is small at the portion where the amount of spraying is small. In this reference example, the ring-shaped pattern 16Y formed in the opening 16X has a function of inhibiting the etching solution from the shower nozzle 19 from being sprayed onto the copper foil 12. For this reason, since the etching amount is less at the position facing the ring-shaped pattern 16Y of the copper foil 12 than at other portions in the opening 16X, the convex portion 14a is formed. Therefore, in this reference example, the concavo-convex portion 14 is formed at a position facing the opening 16X of the copper foil 12.

  When the concavo-convex portion 14 is formed on the copper foil 12 in this manner, the concavo-convex connection pad 28 is formed on the concavo-convex portion 14 as shown in FIG. 11C by electrolytic plating using the copper foil 12 as a plating power feeding layer. Is formed. The uneven connection pad 28 is formed in the opening 16 </ b> X formed in the resist film 16, and includes a pad surface plating layer 25 and a pad body 26.

  The pad surface plating layer 25 is formed of an Au film 25a, a Pd film 25b, and a Ni film 25c as shown in an enlarged view in FIG. Therefore, also in this reference example, in order to form the uneven connection pad 28, the pad surface plating layer 25 is first formed by sequentially plating the Au film 25a, the Pd film 25b, and the Ni film 25c, and then the pad surface. A pad body 26 made of Cu is formed on the plating layer 25 by plating.

  Thus, when the uneven | corrugated connection pad 28 is formed on the uneven | corrugated | grooved part 14 of the copper foil 12, each manufacturing process demonstrated using FIG. 3 (B)-FIG. 1A is manufactured. Each process of the manufacturing process performed in FIGS. 3B to 6 is the same process as that described in the above-described embodiment, and the description thereof will be omitted.

  FIG. 12A shows an enlarged view of the uneven connection pad 28 exposed from the first insulating layer 20. As shown in the figure, the surface shape of the concavo-convex connection pad 28 is a shape obtained by transferring the shape of the concavo-convex portion 14 shown in FIG. 11B, and the shape is a convex spherical shape. The concave portion is partially formed on a part of the curved surface. Specifically, a curved surface portion 28a having a concavo-convex shape is formed in a portion exposed from the surface of the wiring board (surface of the first insulating layer 20) of the concavo-convex connection pad 28, and the pad surface plating is formed on the surface of the curved surface portion 28a. The layer 25 is formed.

  FIG. 12B shows a state in which the semiconductor chip 40 is mounted on the wiring board 1A manufactured by the manufacturing method according to the first reference example. In the example shown in the figure, ball-shaped terminals 40b made of solder are provided on the semiconductor chip 40, and the ball-shaped terminals 40b are joined to the uneven connection pads 28 of the wiring board 1A.

As described above, the surface of the concavo-convex connection pad 28 has a shape in which a concave portion is partially formed on a part of a spherical curved surface, in other words, a shape in which concavo-convex is formed on the surface. For this reason, the surface area of the concavo-convex connection pad 28 in contact with the ball-shaped terminal 40b is increased as compared with a configuration in which there is no concavo-convex, and thus the bonding strength between the ball-shaped terminal 40b and the concavo-convex connection pad 28 can be increased. Therefore, also in the wiring board 1A manufactured according to this reference example, mechanical and electrical connectivity with the semiconductor chip 40 (electronic device) mounted thereon can be improved.
(Second reference example of the present invention)
Next, a second reference example of the present invention will be described. 13 and 14 show a method of manufacturing a wiring board according to a second reference example of the present invention. 13 and 14, the same reference numerals are given to the components corresponding to those shown in FIGS. 1 to 12, and the description thereof is omitted.

  FIG. 13A shows a state in which a resist film 16 is formed on the support 10 in which the pair of copper foils 12 are bonded by the adhesive 11. The state shown in FIG. 11A corresponds to the state shown in FIG.

  In the above-described embodiment and the first reference example, by using the resist film 16 as an etching resist and performing an etching process on the copper foil 12, the curved convex connection pad 18 and the concave / convex connection formed on the copper foil 12 are performed. A method was used in which the surface shape of the pad 28 is a shape having uneven concave portions and convex portions that are not flat.

  On the other hand, the present reference example is characterized in that the resist film 16 is used as a plating resist and the curved convex portion 15 is formed on the copper foil 12 by copper plating. FIG. 13B shows a state in which the curved convex portion 15 is formed by plating the copper foil 12.

As this plating method, for example, it is desirable to use a method disclosed in JP-A-2001-291554. In this plating method, by increasing the current density by 10 to 20 percent (1.1 to 1.2 A / dm ² ), the curved convex portion 15 can be formed on the flat copper foil 12 in the opening portion 16X. . By using this method, the surface of the curved convex portion 15 becomes a spherical curved surface and has a convex shape toward the outside.

  In the subsequent step, the curved convex portion 15 is removed together with the copper foil 12 by etching. For this reason, it is desirable that the material of the curved convex portion 15 formed by the above plating method is a material that is simultaneously etched when the copper foil 12 is removed by etching.

  Thus, when the curved convex part 15 is formed in the copper foil 12, the curved convex part 15 is formed on the curved convex part 15 as shown in FIG. 13C by electrolytic plating using the copper foil 12 as a plating power supply layer. A connection pad 38 is formed. The curved concave connection pad 38 is formed in the opening 16X formed in the resist film 16, and is composed of the pad surface plating layer 25 and the pad body 26. Also in this reference example, in order to form the curved concave connection pad 38, first, the pad surface plating layer 25 is formed by sequentially plating the Au film 25a, the Pd film 25b, and the Ni film 25c, and then the pad surface plating. A pad body 26 made of Cu is formed on the layer 25 by plating.

  When the curved concave connection pad 38 is formed on the curved convex portion 15 of the copper foil 12 as described above, each manufacturing process described with reference to FIGS. 3B to 6 described in the above embodiment is performed. Then, the wiring board 1B is manufactured. At this time, in the present reference example, the curved convex portion 15 is configured to protrude from the surface of the copper foil 12, so that the wiring member 30 is separated from the support 10 described with reference to FIGS. 4 (B) and 5 (A). When the copper foil 12 is subsequently removed, the curved convex portion 15 is also removed. For this reason, each curved concave connection pad 38 has a concave pad shape as shown in FIG.

  A specific shape of the curved concave connection pad 38 is that a curved surface portion 38a having a concave shape is formed on a portion of the curved concave connection pad 38 exposed from the surface of the wiring board (the surface of the first insulating layer 20). The pad surface plating layer 25 is formed on the surface.

  As described above, it is desirable that the material of the curved convex portion 15 formed by the plating method is a material that is simultaneously etched when the copper foil 12 is removed by etching. However, the curved convex portion 15 is made of a material different from that of the copper foil 12, and after removing the copper foil 12 with the etching solution (first etching solution), the curved convex portion 15 different from the etching solution of the copper foil 12. It is also possible to remove the material with an etchant (second etchant) capable of etching.

  The curved concave connection pad 38 from which the copper foil 12 has been removed is mounted with solder balls 29a as shown in FIG. 14 (B), and then a reflow process is performed, so that FIG. A curved concave connection pad 38 to which solder bumps 29 are joined as shown is formed.

  When the solder bump 29 is formed, the curved concave connection pad 38 has a spherical concave shape, so that the solder ball 29a is self-aligned at the center of the curved concave connection pad 38, and thus the positioning of the solder ball 29a. Can be easily performed. In addition, the bonding area between the curved concave connection pad 38 and the solder bump 29 can be increased, and the bonding reliability between the solder bump 29 and the curved concave connection pad 38 can be increased. FIG. 14D shows a state in which the semiconductor chip 40 is mounted on the wiring board 1B manufactured by the manufacturing method according to this reference example.

  In the above reference example, the solder bump 29 is formed on the curved concave connection pad 38, but the solder bump 29 is not formed on the curved concave connection pad 38, and a solder ball is mounted on the semiconductor chip 40 side. It is good also as a structure. In this configuration, since the solder balls disposed on the semiconductor chip 40 side are self-aligned by the curved concave connection pads 38 as described above, the semiconductor chip 40 can be easily positioned with respect to the wiring board 1B.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments described above, and various modifications are possible within the scope of the gist of the present invention described in the claims. It can be modified and changed.

  Specifically, a pair of copper foils 12 are disposed via a prepreg (temporary substrate), and a composite functioning as a support is formed by adhering only the outer edge, and both sides of the composite are formed. A build-up wiring layer may be formed. Moreover, it is good also as a structure which forms a buildup wiring layer only in the single side | surface of one copper foil (support body).

1A to 1C are cross-sectional views (part 1) for explaining a method of manufacturing a wiring board according to an embodiment of the present invention. 2A and 2B are cross-sectional views (part 2) for explaining the method of manufacturing the wiring board according to the embodiment of the present invention. 3A to 3E are cross-sectional views (part 3) for explaining the method of manufacturing the wiring board according to the embodiment of the present invention. 4A and 4B are cross-sectional views (part 4) for explaining the method of manufacturing the wiring board according to the embodiment of the present invention. 5A to 5C are cross-sectional views (No. 5) for explaining the method of manufacturing the wiring board according to the embodiment of the invention. FIG. 6 is a sectional view (No. 6) for explaining the method of manufacturing the wiring board according to the embodiment of the invention. FIG. 7 is a cross-sectional view (No. 1) showing a state in which a semiconductor chip is mounted on a wiring board manufactured by the wiring board manufacturing method of one embodiment of the present invention. FIG. 8 is an enlarged view showing the joint position between the curved convex pad and the post-like terminal in FIG. 9A and 9B are cross-sectional views (part 2) showing a state in which a semiconductor chip is mounted on a wiring board manufactured by the method for manufacturing a wiring board according to an embodiment of the present invention. FIG. 10 is a cross-sectional view showing a state in which a semiconductor chip is mounted on a wiring board manufactured by a method of manufacturing a wiring board, which is a modification of the embodiment of the present invention. 11A to 11C are cross-sectional views (No. 1) for explaining the method for manufacturing the wiring board of the first reference example of the present invention. 12A and 12B are cross-sectional views (part 2) for explaining the method of manufacturing the wiring board according to the first reference example of the invention. 11A to 11C are cross-sectional views (No. 1) for explaining the method of manufacturing the wiring board according to the second reference example of the invention. 12A to 12D are cross-sectional views (part 2) for explaining the method of manufacturing the wiring board according to the second reference example of the present invention.

Explanation of symbols

1, 1A, 1B Wiring board 10 Support 12 Copper foil 13 Curved concave portion 14 Convex portion 15 Curved convex portion 16 Resist film 16X Opening portion 16Y Ring-shaped pattern 18 Curved convex pad 18a Second wiring layer 18b Third wiring layer 18c 4th wiring layer 19 Shower nozzle 20 1st insulating layer 22 Solder resist 25 Pad surface plating layer 26 Pad main body 28 Uneven pad 29 Solder bump 30 Wiring member 38 Curved concave pad 40 Semiconductor chip A Wiring formation area B Outer peripheral part

Claims (6)

A method of manufacturing a wiring board on which a semiconductor chip is mounted,
Forming a concave curved surface that is recessed at a position corresponding to the formation position of the connection pad of the wiring board on the surface of the support;
Forming a pad body on the concave curved surface portion of the support;
Forming a wiring member in which a wiring layer and an insulating layer are laminated on the support;
Forming a connection pad having a curved shape protruding from the substrate surface corresponding to the concave curved surface formed on the support by removing the support from the wiring member;
Soldering post-like terminals that serve as external connection terminals of the semiconductor chip to the connection pads;
Forming the wiring member includes forming a via hole in the insulating layer to expose the pad body ;
Forming a wiring layer for electrically connecting the connection pads through the via holes on the insulating layer. Forming a pad surface plating layer on the curved surface of the concave recessed front Symbol support, according to claim 1, characterized in that a step of forming the pad body to the pad surface plated layer A method for manufacturing a wiring board. The formation of the connection pads, method of manufacturing a wiring board according to any one of claims 1 or 2, characterized in that the electrolytic plating of the support as a power feeding layer. A wiring member in which a wiring layer and an insulating layer are laminated;
A connection pad connected to the wiring layer, protruding from the substrate surface and having a curved surface on the surface;
A wiring board having a semiconductor chip,
The connection pad is made of plating ,
The wiring member is formed by laminating the wiring layer made of plating and the insulating layer made of resin,
The connection pad is provided on the outermost insulating layer forming the wiring board surface,
The connection pad includes a curved first surface exposed from the outermost insulating layer surface and protruding from the outermost insulating layer surface, and the first surface embedded in the outermost insulating layer. An opposite second surface,
The second surface and the wiring layer are connected via a via hole provided in the outermost insulating layer ;
A wiring board having a configuration in which post-like terminals serving as external connection terminals of the semiconductor chip are soldered to the connection pads. 5. The semiconductor device according to claim 4 , wherein at least a part of the first surface is formed by a pad surface plating layer, and post terminals of the semiconductor chip are soldered through the pad surface plating layer. Wiring board. The connection pad is composed of a pad surface plating layer and a pad body made of copper plating,
The wiring board according to claim 4 , wherein the wiring layer is formed by copper plating.

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