JP2010232616A - Semiconductor device, and wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device and a wiring board, capable of high-density mounting without increasing the thickness of a wiring board. <P>SOLUTION: This semiconductor device 10 includes this wiring board 20, and an electronic component 30 mounted on the wiring board 20. The wiring board 20 includes a wiring pattern 21, an insulation layer 22, and auxiliary pads 23. The wiring pattern 21 includes wires 24 and mounting pads 25 each having a diameter larger than the width of the wire 24. The insulation layer 22 covers the surface of the wiring pattern 21. The auxiliary pad 23 has a diameter larger than that of the mounting pad 25, and is arranged on the insulation layer 22 corresponding to the mounting pad 25. The electronic component 30 includes electrodes 31 each connected to the auxiliary pad 23 or the auxiliary pad 23 and the mounting pad 25 through a conductive member 40. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor device and a wiring board, and more particularly to a semiconductor device and a wiring board having a structure in which an electronic component is mounted on the wiring board via a conductive member.

  In recent years, electronic devices typified by mobile phones and notebook PCs have been reduced in size, thickness, and functionality. For this reason, module components combined with electronic components are required to have higher density mounting. For example, in electronic components, the number of pins is increased and the pitch between electrodes is being reduced.

  As electronic parts that are suitably used for high-density mounting, for example, those having a BGA (ball grid array) or CSP (chip size package) in which electrodes are arranged in a grid on the lower surface of the case are known. . These electronic components are mounted when mounted on a wiring board, for example, compared to electronic components having QFP (quad flat package) or SOP (small outline package) using lead frames arranged on the side surfaces of the case as electrodes. The area is small.

  Patent Documents 1 to 3 describe various wiring boards on which electronic components suitable for such high-density mounting are mounted via conductive members such as solder.

  Patent Document 1 describes a semiconductor device having an electronic component having a plurality of electrodes formed on the lower surface and a wiring board on which the electronic component is mounted. The wiring board includes a core substrate having wiring formed on a surface layer (substrate surface), a buildup layer including insulating layers and conductor circuit layers alternately stacked on both upper and lower surfaces of the core substrate, and a plurality of electrodes of an electronic component And a solder bump part (conductive member) that contacts each of them. A barrier layer is disposed around the solder bump portion. The barrier layer is formed in the opening of the stress relaxation layer formed on the insulating layer, and the lower surface is in contact with the conductor circuit layer.

  In Patent Document 2, a mounting pad formed on a surface layer, an insulating layer having an opening formed corresponding to the mounting pad and covering the surface of the mounting pad, and the mounting pad and the insulating layer are provided. A wiring board having first and second base metal layers provided and bumps formed on the second base metal layer is described.

  In Patent Document 3, wirings and mounting pads formed on the surface layer, an insulating layer having openings formed corresponding to the mounting pads and covering the wirings and mounting pads, and formed in the openings A wiring board having an auxiliary pad connected to a mounting pad through a conductive member is described.

JP 2006-066597 A JP 2004-228295 A JP 2007-184381 A

  As the number of pins in the electronic component increases and the pitch between electrodes decreases, the spacing (pitch) between adjacent mounting pads on the wiring board has become narrower. For this reason, it is difficult to route the wiring on the surface layer surface of the wiring board without interfering with the mounting pads.

  Therefore, in Patent Document 1, the wiring of the core substrate and the conductor circuit layer of the build-up layer are electrically connected through vias to achieve high-density mounting. However, in this wiring board, the number of layers is increased because the wiring is routed in the inner layer of the wiring board, and the thickness is further increased because the stress relaxation layer is formed on the insulating layer. For this reason, the semiconductor device provided with the wiring board and the electronic component also becomes thick.

  In Patent Document 2, the first and second base metal layers are formed on the mounting pad and the insulating layer in order to prevent the peeling of the bumps due to corrosion. The wiring board becomes thick.

  Further, in Patent Document 3, in order to route the wiring on the surface layer of the wiring board, it is necessary to reduce the width of the wiring as the pitch between the mounting pads becomes narrow, which means that the yield is reduced and the cost is increased. Problems arise. Further, the conductive member and the auxiliary pad are considered to be separate members, and further, the auxiliary pad is formed on the conductive member, so that the manufacturing process increases.

  An object of the present invention is to provide a semiconductor device and a wiring board that can be mounted at high density without increasing the thickness of the wiring board.

In order to achieve the above object, the present invention provides a wiring pattern including a wiring and a mounting pad having a diameter larger than the width of the wiring, an insulating layer covering the surface of the wiring pattern, and larger than the mounting pad. A wiring board having a diameter and an auxiliary pad disposed on the insulating layer corresponding to the mounting pad;
There is provided a semiconductor device comprising: the auxiliary pad, or an electronic component having an electrode connected to the auxiliary pad and the mounting pad through a conductive member and mounted on the wiring board.

According to another aspect of the present invention, there is provided a wiring pattern including a wiring and a mounting pad having a diameter larger than the width of the wiring, and a first opening formed corresponding to the mounting pad. An insulating layer for covering, and an auxiliary pad having a diameter larger than that of the mounting pad and disposed on the insulating layer corresponding to the mounting pad;
Provided is a wiring substrate in which the auxiliary pad is connected to the mounting pad through the first opening.

Furthermore, the present invention includes a wiring pattern including a wiring and a mounting pad having a diameter larger than the width of the wiring, and a first opening formed corresponding to the mounting pad. An insulating layer for covering, and an auxiliary pad having a diameter larger than that of the mounting pad and disposed on the insulating layer corresponding to the mounting pad;
The auxiliary pad provides a wiring board having a second opening above the first opening.

  In the semiconductor device and the wiring board of the present invention, high-density mounting is possible without increasing the thickness of the wiring board.

1 is a cross-sectional view showing a configuration of a semiconductor device according to a first embodiment of the present invention. Sectional drawing which shows the structure of the modification of the semiconductor device shown in FIG. (A) And (b) is sectional drawing which shows the structure of the semiconductor device which is a comparative example. (A) And (b) is sectional drawing which shows the structure of the semiconductor device which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows the structure of the modification of the semiconductor device shown to Fig.4 (a).

  The semiconductor device of the present invention includes a wiring board and an electronic component mounted on the wiring board as a minimum basic configuration. The wiring board has a wiring pattern, an insulating layer, and an auxiliary pad. The wiring pattern includes a wiring and a mounting pad having a diameter larger than the width of the wiring. The insulating layer covers the surface of the wiring pattern. The auxiliary pad has a larger diameter than the mounting pad, and is disposed on the insulating layer corresponding to the mounting pad. The electronic component has an auxiliary pad or an electrode connected to the auxiliary pad and the mounting pad via a conductive member.

  In the semiconductor device, since the auxiliary pad having a larger diameter than the mounting pad is disposed on the insulating layer, when the electronic component is mounted on the wiring board, the conductive member is the auxiliary pad or the auxiliary pad and the mounting. Connected to the pad. For this reason, since the diameter of the mounting pad formed on the surface layer surface of the wiring board can be reduced, the interval between the mounting pads adjacent on the surface layer surface is increased. As a result, it is not necessary to increase the number of layers of the wiring substrate and route the wiring in the inner layer of the wiring substrate, and the wiring can be routed on the surface layer surface of the wiring substrate. Therefore, high-density mounting is possible without increasing the thickness of the wiring board. In addition, since the number of layers of the wiring board is reduced, the semiconductor device including the wiring board can be thinned.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration of a semiconductor device according to the first embodiment of the present invention. The semiconductor device 10 includes a wiring board 20 and an electronic component 30, and has a structure in which the electronic component 30 is mounted on the wiring board 20 via a conductive member 40. The wiring board 20 includes a wiring pattern 21, an insulating layer (insulating member) 22, and an auxiliary pad 23. The wiring pattern 21 includes a wiring 24 and a mounting pad 25 having a diameter larger than the width of the wiring 24.

  The insulating layer 22 has a first opening 26 formed corresponding to the mounting pad 25 and covers the surface of the wiring pattern 21. The insulating layer 22 is made of, for example, a solder resist. By forming the insulating layer 22 with a solder resist, the solder resist necessary for forming the wiring pattern 21 including the wiring 24 and the mounting pad 25 can be used as it is, so that the manufacturing process can be simplified. The insulating layer 22 is not limited to a solder resist.

  The auxiliary pad 23 has a diameter larger than that of the mounting pad 25, is disposed on the insulating layer 22 corresponding to the mounting pad 25, and is mounted through the first opening 26 of the insulating layer 22. It is directly connected to the pad 25. Examples of the material of the auxiliary pad 23 include a conductive paste, a conductive resin, a conductive adhesive, and a metal such as Cu, but any material can be used as long as the conductive member 40 has wettability. . When the material of the auxiliary pad 23 is composed of a conductive paste or a conductive adhesive, it is applied on the insulating layer 22 and in the first opening 26 using an existing method such as a printing method or a dispensing method. The auxiliary pad 23 can be formed.

  Further, if the auxiliary pad 23 has a wettability with respect to the conductive member 40, the conductive member 40 can be prevented from flowing out from the auxiliary pad 23 onto the insulating layer 22. When the material of the auxiliary pad 23 does not have wettability to the conductive member 40, the surface of the auxiliary pad 23 may be subjected to treatment such as Au plating so as to obtain wettability to the conductive member 40. Good.

  The electronic component 30 is a BGA, a CSP, or the like, and has a plurality of electrodes 31 arranged on the lower surface. The electrode 31 is electrically connected to the auxiliary pad 23 via the conductive member 40. The conductive member 40 is made of, for example, solder or conductive resin. Here, the conductive member 40 is a solder ball bonded in advance to the electrode 31. Examples of the solder material include Sn—Pb, Sn—Ag—Cu, Sn—Ag, Sn—Cu, Sn—Sb, Sn—Zn, Sn—In, and the like. Not. 1 shows a cross section including the center of the mounting pad 25, and the positions of the auxiliary pad 23 and the mounting pad 25 correspond to the positions of the electrodes 31, as shown.

  Next, a method for manufacturing a semiconductor device will be described. First, the wiring pattern 21 including the wiring 24 and the mounting pad 25 is formed on the wiring substrate 20, and then the insulating layer 22 is formed so as to cover the wiring 24 and the mounting pad 25. Next, exposure and development are performed to form a first opening 26 in the insulating layer 22 on the mounting pad 25.

  Subsequently, the auxiliary pad 23 is formed on the first opening 26 and the insulating layer 22 around the first opening 26 by a printing method. Next, the electronic component 30 is mounted on the wiring board 20 in a state where the conductive member 40 bonded to the electrode 31 of the electronic component 30 is aligned with the center of the mounting pad 25. Thereafter, heat is applied by a reflow method or the like to melt the conductive member 40, and the electronic component 30 is mounted on the wiring board 20.

  Through the above steps, the semiconductor device 10 shown in FIG. 1 can be manufactured. In this embodiment, the conductive member 40 is a solder ball, the insulating layer 22 is formed of a solder resist, and the conductive member 40 is not filled with an underfill. However, there is no particular limitation as long as the electronic component 30 is mounted on the mounting pad 25 on the wiring board 20 via the conductive member 40.

  Next, routing of the wiring 24 on the wiring board 20 will be described. As described above, the semiconductor device 10 has a structure in which the electrode 31 of the electronic component 30 and the mounting pad 25 on the wiring board 20 are mounted via the conductive member 40. In this structure, it is necessary to route the wiring 24 without interfering with the mounting pad 25 of the wiring board 20 in order to obtain an electrical connection from the mounting pad 25 to another electronic component 30 or the like.

  Therefore, in the present embodiment, the auxiliary pad 23 having a larger diameter than the mounting pad 25 and connected to the mounting pad 25 via the first opening 26 is disposed on the insulating layer 22. Therefore, the conductive member 40 is electrically connected to the mounting pad 25 via the auxiliary pad 23 in a state where the electronic component 30 is mounted on the wiring board 20. That is, the conductive member 40 is directly connected to the auxiliary pad 23 and indirectly connected to the mounting pad 25. For this reason, the diameter of the mounting pad 25 formed on the surface of the wiring board 20 can be reduced.

  By reducing the diameter of the mounting pad 25, the interval between the mounting pads 25 adjacent on the surface layer surface is increased, and as a result, the wiring 24 formed on the surface layer surface of the wiring substrate 20 is replaced with the surface layer surface of the wiring substrate 20. Can be routed with. Therefore, in this embodiment, high-density mounting is possible without increasing the thickness of the wiring board 20. Further, since the number of layers of the wiring board 20 can be reduced, the semiconductor device 10 including the wiring board 20 can be thinned.

  Next, with reference to FIG. 2 and FIG. 3, a description will be given of the routing of wiring on the wiring board when an electronic component that is a CSP having electrode pitches of 0.3 mm is mounted on the wiring board. FIG. 2 is a cross-sectional view showing a configuration of a modified example of the semiconductor device 10 shown in FIG. 3A and 3B are cross-sectional views illustrating a configuration of a semiconductor device as a comparative example. First, a comparative example will be described with reference to FIG.

  As shown in FIG. 3A, in the electronic component 130 which is a CSP having a pitch of 0.3 mm, the diameter of the electrode 131 is about 200 μm (A ′ in the figure). In the semiconductor device 100, the insulating layer 114 having the first opening 115 covers the mounting pad 112 formed on the surface layer surface of the wiring substrate 110, and the electrode 131 of the electronic component 130 is mounted via the conductive member 120. It is electrically connected to the pad 112 for use.

  In the semiconductor device 100, as shown in the figure, the diameter of the mounting pad 112 on the wiring substrate 110 is also about 200 μm (A ′ in the figure), which is the same as the diameter of the electrode 131. For this reason, the location where the mounting pads 112 do not exist, that is, the interval (B ′ in the figure) between the adjacent mounting pads 112 is about 100 μm. With such a narrow interval, it is difficult to route the wiring 111 without interfering with the mounting pads 112 on the surface layer surface of the wiring substrate 110.

  Therefore, the semiconductor device 100 has a structure in which the wiring 111 is electrically connected to the mounting pad 112 through the via 113 and is routed in the inner layer of the wiring substrate 110. In this structure, the number of layers of the wiring board 110 increases each time the wiring 111 increases, and the wiring board 110 itself becomes thick.

  Therefore, in the semiconductor device 100 of the comparative example, when the high-density mounting is achieved, the wiring board 110 becomes thick, and the semiconductor device 100 itself increases in thickness.

  Subsequently, the semiconductor 100A as a comparative example shown in FIG. 3B employs a structure in which the distance between the adjacent mounting pads 112A is not reduced by reducing the diameter of the mounting pads 112A. In the semiconductor device 100A, a wiring pattern including the wiring 111A and a mounting pad 112A having a small diameter is formed on the surface of the wiring substrate 110A. An insulating layer 114A having a first opening 115A covers the wiring 111A and the mounting pad 112A.

  However, in the semiconductor device 100A, when the electronic component 130 is mounted on the wiring board 110A via the conductive member 120A, which is a solder ball, the solder ball is mounted on the mounting pad 112A because the diameter of the mounting pad 112A is small. It will be too big. As a result, in the semiconductor device 100A, when the solder ball is melted, as shown in the figure, the adjacent solder ball is short-circuited, and the connection strength between the mounting pad 112A and the conductive member 120A is reduced, so that the reliability is lowered. Resulting in.

  On the other hand, in the semiconductor device 10A of the present embodiment shown in FIG. 2, the conductive member 40A is connected to the mounting pad 25 via the auxiliary pad 23A. That is, the conductive member 40A is directly connected to the auxiliary pad 23A and indirectly connected to the mounting pad 25. Therefore, even if the diameter of the electrode 31 of the electronic component 30 is about 200 μm as described above, the diameter of the mounting pad 25 is set to about 100 μm (in the drawing, for example) by setting the outer peripheral diameter of the auxiliary pad 23A to about 200 μm. A) It can be made as small as possible.

  Since the diameter of the mounting pad 25 is reduced, the interval between the adjacent mounting pads 25 is about 200 μm (B in the figure) including directly under the auxiliary pad 23A via the insulating layer 22A formed of solder resist. It becomes. That is, in the wiring board 20A, a sufficient space for routing the wiring can be secured between the adjacent mounting pads 25, so that the wiring can be routed on the surface layer, and the number of layers of the wiring board 20A is increased. Therefore, high-density mounting can be achieved. For this reason, the semiconductor device 10A can be thinned.

  As an example, if the width and space (L / s) of the wiring is 40 μm / 40 μm, it is illustrated between the adjacent mounting pads 25 and immediately below the auxiliary pad 23A formed on the insulating layer 22A. As described above, a plurality of (in this case, two) wirings 24a and 24b can be routed. That is, the wiring pattern 21A including the mounting pad 25 and the wirings 24a and 24b is formed on the surface layer surface of the wiring board 20A.

  Thus, in the semiconductor device 10A of the present embodiment, by providing the auxiliary pad 23A connected to the conductive member 40A on the insulating layer 22A, the wiring is drawn on the surface layer surface of the wiring board 20A such as immediately below the auxiliary pad 23A. More points can be turned. Therefore, high-density mounting is possible without increasing the number of layers of the wiring board 20A, and the thickness can be reduced.

  In the present embodiment, the pitch of the electrodes 31 of the electronic component 30 is 0.3 mm. However, the present invention is not limited to this, and the same effect as described above can be obtained even with other pitch sizes. Further, the size and shape of the electronic component 30 are not particularly limited because the same effect can be obtained.

(Second Embodiment)
FIG. 4 is a cross-sectional view showing a configuration of a semiconductor device according to the second embodiment of the present invention. The semiconductor device 10B shown in FIG. 4A is different from the semiconductor device 10 shown in FIG. 1 in that the auxiliary pad 23B has the second opening 27.

  In the semiconductor device 10B, since the auxiliary pad 23B has the second opening 27, the electrode 31 is wired via the first opening 26 and the conductive member 40B formed in the second opening 27. It is connected to a mounting pad 25 on the surface of the substrate 20B. For this reason, since the conductive member 40B is directly connected not only to the auxiliary pad 23B but also to the mounting pad 25, the electrical reliability is improved.

  Further, in the semiconductor device 10B, the conductive member 40B is formed in the second opening 27 of the auxiliary pad 23B and the first opening 26 of the insulating layer 22, and the auxiliary pad 23B is the first opening of the insulating layer 22. It is formed around the opening 26. Therefore, it is possible to prevent the conductive member 40B from flowing on the insulating layer 22 and short-circuiting with the adjacent mounting pad 25. Further, since the auxiliary pad 23B is formed with the second opening 27, the auxiliary pad 23B has a smaller area than the auxiliary pad 23 of the semiconductor device 10 and uses less material, thereby reducing the cost. it can.

  In the semiconductor device 10C shown in FIG. 4B, the material forming the auxiliary pad 23C is applied to, for example, the wall surfaces 28 of the first opening 26 of the insulating layer 22 and the second opening 27 of the auxiliary pad 23C. This is different from the semiconductor device 10B shown in FIG. As an example, this structure is obtained when the auxiliary pad 23C is formed in the printing process or the dispensing process, and a positional shift occurs and the application location is slightly shifted.

  Such a semiconductor device 10C also has a structure in which the electrode 31 of the electronic component 30 and the mounting pad 25 on the wiring board 20C are mounted via the conductive member 40C. Therefore, the same effect as the semiconductor device 10B is obtained. Can be obtained.

  FIG. 5 is a cross-sectional view showing a configuration of a modified example of the semiconductor device 10B shown in FIG. The semiconductor device 10D includes a plurality of (here, two) wirings 24a and 24b between adjacent mounting pads 25 and immediately below the auxiliary pad 23D formed on the insulating layer 22A as shown in the figure. Is different from the semiconductor device 10B in that it is routed on the surface of the wiring board 20D. Further, the wirings 24a and 24b shown in FIG. 5 have a smaller width than the wiring 24 shown in FIG. Note that the semiconductor device 10D also has a structure in which the electrode 31 of the electronic component 30 and the mounting pad 25 on the wiring board 20D are mounted via the conductive member 40D.

  For this reason, in the semiconductor device 10 </ b> D, the plurality of wirings 24 a and 24 b can be sufficiently routed between the adjacent mounting pads 25. Therefore, further high-density mounting is possible without increasing the number of layers of the wiring board 20D.

  In addition, the planar shape of each mounting pad and auxiliary pad described above can adopt a square, a rectangle, and other various shapes.

  As described above, the present invention has been described based on the preferred embodiments. However, the semiconductor device and the wiring board according to the present invention are not limited to the configurations of the above embodiments, and various modifications can be made from the configurations of the above embodiments. Further, modifications and changes are also included in the scope of the present invention.

10, 10A to 10D: Semiconductor devices 20, 20A to 20D: Wiring substrates 21, 21A: Wiring patterns 22, 22A: Insulating layers 23, 23A to 23D: Auxiliary pads 24, 24a, 24b: Wiring 25: Mounting pads 26: 1st opening 27: 2nd opening 28: Wall surface 30: Electronic component 31: Electrode 40, 40A-40D: Conductive member

Claims (8)

A wiring pattern including a wiring and a mounting pad having a diameter larger than the width of the wiring; an insulating layer covering a surface of the wiring pattern; and a diameter larger than the mounting pad and corresponding to the mounting pad A wiring board having an auxiliary pad disposed on the insulating layer;
A semiconductor device comprising: the auxiliary pad, or an electronic component having an electrode connected to the auxiliary pad and the mounting pad through a conductive member and mounted on the wiring board.   The insulating layer has a first opening formed corresponding to the mounting pad, and the auxiliary pad has a second opening formed above the first opening. The semiconductor device according to claim 1, wherein the electrode and the mounting pad are connected via the conductive member formed in the opening of 2. The insulating layer has a first opening formed corresponding to the mounting pad;
The semiconductor device according to claim 1, wherein the auxiliary pad is connected to the mounting pad through the first opening and is connected to the electrode through the conductive member.   The semiconductor device according to claim 1, wherein the auxiliary pad has wettability with respect to solder constituting the conductive member.   The semiconductor device according to claim 1, wherein the insulating layer is formed of a solder resist.   The semiconductor device according to claim 1, wherein the wiring extends immediately below the auxiliary pad portion. A wiring pattern including a wiring and a mounting pad having a diameter larger than the width of the wiring; an insulating layer having a first opening formed corresponding to the mounting pad and covering the surface of the wiring pattern; An auxiliary pad disposed on the insulating layer corresponding to the mounting pad and having a larger diameter than the mounting pad;
A wiring board in which the auxiliary pad is connected to the mounting pad through the first opening. A wiring pattern including a wiring and a mounting pad having a diameter larger than the width of the wiring; an insulating layer having a first opening formed corresponding to the mounting pad and covering the surface of the wiring pattern; An auxiliary pad disposed on the insulating layer corresponding to the mounting pad and having a larger diameter than the mounting pad;
The wiring board, wherein the auxiliary pad has a second opening above the first opening.

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