JP2010232439A - Wiring board, method of manufacturing the same, and electronic device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such the problem that since it is difficult to change a plating liquid in a recessed portion when a plating layer is formed on the side face of the recessed portion, the plating layer becomes thinner at a part of the side face of the recessed portion close to the opening of the recessed portion than at a part close to the bottom of the recessed portion because of what is called an edge effect. <P>SOLUTION: A wiring board includes an insulating base having the recessed portion on a principal surface, a wiring conductor arranged on the side face of the recessed portion, and plating arranged on the wiring conductor, oriented in a (1, 1, 0) direction from the side face to the center axis of the recessed portion, and made principally of Ni. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a wiring board having a recess, in particular, a surface mounting type wiring board, a wiring board used for a CMOS, a CCD, and the like.

  In a wiring board used for a CMOS, a CCD, or the like, a through castellation is provided at an end of the wiring board, and a socket is mounted on the through castellation. In such a wiring board, a through hole is formed at the end of the insulating substrate, a wiring conductor is provided on the surface of the through hole, and a plating layer is provided on the surface of the wiring conductor by a technique such as a watt bath. ing.

  In recent years, such wiring boards are required to be miniaturized. Therefore, as disclosed in Patent Document 1, there has been proposed a wiring board using a non-penetrating castellation in which a concave portion is formed instead of forming a through hole in an end portion of an insulating base. Thus, by using a non-penetrating type castellation, it is possible to secure a wider area for mounting electronic components on the back surface of the wiring board.

JP 2004-312048 A

  However, when non-penetrating castellations are used, it is difficult to reduce the variation in the thickness of the plating layer disposed on the surface of the wiring conductor. This is because when a recess is provided in an insulating substrate and a plating layer is formed on the side surface of the recess, it is difficult to replace the plating solution existing in the recess. This is because the plating layer in the portion near the opening of the recess becomes smaller than the thickness of the plating layer in the portion near the bottom.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a wiring board having a small variation in the thickness of the plating layer in the recess.

  The wiring board according to the present invention includes an insulating base having a recess on a main surface, a wiring conductor disposed on a side surface of the recess, a wiring conductor disposed on the wiring conductor, and extending from the side surface of the recess to the recess. And plating mainly composed of Ni oriented in the (1, 1, 0) direction toward the central axis.

  According to the wiring board of the present invention, as the plating layer, plating mainly composed of Ni oriented in the (1, 1, 0) direction from the side surface of the concave portion toward the central axis is used. Therefore, variation in the thickness of the plating layer in the recess can be reduced. This is because the use of plating mainly composed of Ni oriented in the (1, 1, 0) direction can promote the deposition of plating from the side surface of the recess toward the central axis. As a result, since the plating layer can be formed on the side surface of the recess before the influence of the edge effect appears, variation in the thickness of the plating layer in the recess can be reduced.

It is sectional drawing which shows the wiring board concerning one Embodiment of this invention. FIG. 2 is an enlarged cross-sectional view in which a region A in the wiring board shown in FIG. 1 is enlarged. (A) is a conceptual diagram of Ni plating oriented in the (1, 1, 0) direction, and (b) is a conceptual diagram of Ni plating oriented in the (1, 0, 0) direction. It is sectional drawing which shows the 1st process in the manufacturing method of the wiring board concerning the 1st Embodiment of this invention. It is sectional drawing which shows the 2nd process in the manufacturing method of the wiring board concerning the 1st Embodiment of this invention. It is sectional drawing which shows the 3rd process in the manufacturing method of the wiring board concerning the 1st Embodiment of this invention. It is sectional drawing which shows the electronic device concerning one Embodiment of this invention.

  Hereinafter, the wiring board of the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, a wiring board 1 according to an embodiment of the present invention includes an insulating substrate 5 having a recess 3 on a main surface 5 a, and a wiring conductor 7 disposed on a side surface of the recess 3. And a plating 9 mainly composed of Ni which is disposed on the wiring conductor 7 and is oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis of the recess 3.

  As described above, the wiring board 1 according to the present embodiment uses the plating 9 mainly composed of Ni oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis as the plating layer. Yes. By using the plating 9 described above, precipitation of the plating 9 in the thickness direction is promoted, so that the thickness of the plating 9 from the side surface of the recess 3 toward the central axis of the recess 3 can be quickly increased. it can. For this reason, the influence of the edge effect can be reduced, so that the variation in the thickness of the plating 9 in the recess 3 can be reduced.

  The wiring board 1 according to the present embodiment includes an insulating substrate 5 having a recess 3 on a main surface 5a. As the insulating substrate 5, it is preferable to use a member having good insulating properties. Specifically, for example, a material mainly composed of a ceramic material such as alumina ceramics or mullite ceramics can be used.

  The shape of the recess 3 is not particularly limited as long as it has a bottom surface and a side surface and is open to the main surface 5a side. For example, it may be circular when viewed in plan, or may be rectangular. In addition, the central axis of the recess 3 in the present embodiment means an axis that passes through the center of the bottom surface of the recess 3 and is perpendicular to the main surface 5 a of the insulating substrate 5. The center of the recess 3 is, for example, the center of a circle when the recess 3 is circular when viewed in plan, and the intersection of vertices when the recess 3 is rectangular when viewed in plan. That's fine.

  The wiring board 1 according to this embodiment includes a wiring conductor 7 disposed on the side surface of the recess 3. Like the wiring board 1 according to the present embodiment, the wiring conductor 7 may be disposed not only on the side surface of the recess 3 but also on the main surface 5 a of the insulating substrate 5. As the wiring conductor 7, it is preferable to use a member having good conductivity. As the member having good conductivity, for example, a metal member such as Au, Ag, Cu, Al, Pt, Pd, Mn, W, and Mo can be used.

  As shown in FIGS. 1 and 2, the wiring board 1 according to the present embodiment includes a surface conductor 11 disposed on the back surface 5 b of the insulating substrate 5. The surface conductor 11 is electrically connected to the wiring conductor 7 via an internal conductor 13 and a via conductor 15 described later. By electrically connecting the surface conductor 11 to the electronic component 21 disposed on the back surface 5b of the insulating substrate 5, the electronic component is connected via the wiring conductor 7, the internal conductor 13, the via conductor 15 and the surface conductor 11. Power can be supplied to 21.

  Moreover, the wiring board 1 according to the present embodiment includes an internal conductor 13 embedded in the insulating base 5 as shown in FIGS. The internal conductor 13 is electrically connected to the surface conductor 11 and the wiring conductor 7 via via conductors 15 respectively. As the internal electrodes, the via conductors 15 and the surface conductors 11, like the wiring conductors 7, it is preferable to use members having good conductivity. As the member having good conductivity, for example, a metal member such as Au, Ag, Cu, Al, Pt, Pd, Mn, W, and Mo can be used.

  The wiring substrate 1 according to the present embodiment is disposed on the wiring conductor 7 and is plated mainly with Ni oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis of the recess 3. 9 is provided. In this way, by disposing the plating 9 on the wiring conductor 7, corrosion of the wiring conductor 7 can be suppressed, so that the durability of the wiring board 1 can be improved. Specifically, Ni—Pd—Au plating and Ni—Au plating can be used as the plating 9 containing Ni as a main component.

  In the present embodiment, it is important that the plating 9 mainly composed of Ni is oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis. As shown in FIG. 3, when the plating 9 oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis is used, in the (1, 0, 0) direction generally used. Since the deposition of the plating 9 in the thickness direction is promoted as compared with the oriented plating, the thickness of the plating 9 from the side surface of the recess 3 toward the central axis can be quickly increased.

  Further, it is preferable to further dispose a plating mainly composed of Au on the surface of the plating 9 mainly composed of Ni in the present embodiment.

  Further, the recess 3 formed on the main surface 5a of the insulating base 5 is located at the end of the main surface 5a of the insulating base 5 and is open to the main surface 5a and side surfaces of the insulating base 5. Is preferred. Thereby, it becomes easy to form a connection between the external wiring (not shown) and the plating 9. Therefore, the bondability between the external wiring and the plating 9 can be improved.

  Moreover, it is preferable that the recessed part 3 formed on the main surface 5a of the insulating base | substrate 5 has a larger internal diameter in an opening part than the internal diameter in the bottom face parallel to the main surface 5a. Thus, when the recessed part 3 is formed, the plating layer in the part close | similar to the opening part of the recessed part 3 is by edge effect rather than the thickness of the plated layer in the part near the bottom part of the recessed part 3 among the side surfaces of the recessed part 3 This is because even if it becomes larger, it is possible to easily replace the plating solution existing in the recess 3. Therefore, the variation between the thickness of the plating 9 near the bottom of the recess 3 and the thickness of the plating 9 near the opening of the recess 3 can be further reduced.

  Next, a method for manufacturing the wiring board 1 according to the first embodiment of the present invention will be described.

  As shown in FIGS. 4 to 6, the method of manufacturing the wiring board 1 according to the present embodiment includes an insulating substrate 5 having a recess 3 on the main surface 5 a and a wiring conductor 7 disposed on the side surface of the recess 3. And a first step of preparing a substrate comprising: a step of immersing the insulating substrate 5 in a plating solution containing Ni, and energizing the wiring conductor 7 to form Ni electrolytic plating 9 on the wiring conductor 7. And a second step of forming. In the second step, the plating solution is irradiated with ultrasonic waves.

  As the Ni electrolytic plating solution, for example, a Watt bath containing nickel sulfate, nickel chloride, boric acid or the like can be used. In addition, a commonly used electrolytic nickel plating solution such as a bright nickel plating solution containing saccharin or the like and a plating solution containing nickel bromide may be used as the Ni electrolytic plating solution.

  Thereby, the plating 9 oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis of the recess 3 can be formed on the surface of the wiring conductor 7 located on the side surface of the recess 3. Variation in the thickness of the plating 9 in the recess 3 can be reduced.

  A first step in the method for manufacturing the wiring board 1 according to the present embodiment will be described.

  First, raw material powders such as glass powder and ceramic powder are kneaded together with an organic solvent and a binder. This is formed into a sheet shape to produce a plurality of ceramic green sheets. Next, a conductor paste to be an internal wiring is deposited on the main surface 5a of the ceramic green sheet. Further, a ceramic green sheet is laminated on the conductor paste. At this time, a through hole serving as the recess 3 is formed in the ceramic green sheet laminated on the conductor paste. A conductor paste to be the surface conductor 11 is deposited on the back surfaces 5b of the plurality of ceramic green sheets laminated in this way. Further, a conductor paste that becomes the wiring conductor 7 is attached to the main surface 5a and the side surfaces of the through holes of the plurality of laminated ceramic green sheets. By firing the plurality of ceramic green sheets laminated as described above, the substrate 17 is produced as shown in FIG.

  In the above-described embodiment, the through hole to be the recess 3 is formed in the ceramic green sheet in advance. However, there is no problem if the recess 3 is formed after firing the laminated ceramic green sheets.

  The shape of the through hole is not particularly limited as long as it has a bottom surface and a side surface and is open to the main surface 5a side. For example, it may be circular when viewed in plan, or may be rectangular. Further, the central axis of the recess 3 in the present embodiment may be replaced with the central axis of the through hole.

  Moreover, it is preferable that the recessed part 3 formed on the main surface 5a of the insulating base | substrate 5 has a larger internal diameter in an opening part than the internal diameter in the bottom face parallel to the main surface 5a. When the concave portion 3 is formed in this way, as already shown, the thickness of the plating 9 in the portion near the bottom of the concave portion 3 and the thickness of the plating 9 in the portion near the opening of the concave portion 3 are varied. This is because can be made smaller.

  In other words, the through hole preferably has a larger inner diameter at the end on the main surface 5a side than an inner diameter at the end on the back surface 5b side. When the through hole is formed in this way, the variation between the thickness of the plating 9 near the bottom of the recess 3 and the thickness of the plating 9 near the opening of the recess 3 can be made smaller. Because it can.

  Next, as shown in FIG. 5, the second step in the method of manufacturing the wiring board 1 according to the present embodiment will be described.

  In the second step, the Ni base plating 9 is formed on the wiring conductor 7 by immersing the insulating substrate 5 in a plating solution containing Ni and energizing the wiring conductor 7. At this time, it is important to irradiate the plating solution with ultrasonic waves. By irradiating the plating solution with ultrasonic waves, the plating 9 oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis of the recess 3 is placed on the surface of the wiring conductor 7 positioned on the side surface of the recess 3. Can be formed.

  At this time, the frequency of the ultrasonic waves is preferably 25 to 50 Hz. Thereby, since the throwing of the plating 9 can be improved, the plating 9 can be formed efficiently. Moreover, it is preferable that the output of an ultrasonic wave is 300-600 kW. When the output of the ultrasonic wave is 300 kW or more, the throwing power of the plating 9 can be improved. Further, since the output of the ultrasonic wave is 600 kW or less, the possibility that the insulating substrate 5 is damaged by the irradiation of the ultrasonic wave can be reduced.

  As the Ni electrolytic plating solution, for example, a Watt bath containing nickel sulfate, nickel chloride, boric acid or the like can be used. In addition, a commonly used electrolytic nickel plating solution such as a bright nickel plating solution containing saccharin or the like and a plating solution containing nickel bromide may be used as the Ni electrolytic plating solution.

  As described above, the wiring board 1 according to the present embodiment can be manufactured.

  As shown in FIG. 6, the method for manufacturing the wiring board 1 according to the present embodiment preferably includes a third step of cutting the base body 17 so as to include the recess 3. In the first step, a substrate may be prepared so as to be one wiring substrate 1, but a plurality of substrates to be the wiring substrates 1 are prepared in a state where the insulating bases 5 are continuous (array substrate). After that, by cutting the substrate 17, a plurality of wiring boards 1 can be manufactured at the same time, so that the productivity of the wiring board 1 can be improved. Further, in the third step, since the substrate is cut so as to include the recess 3, the substrate is located at the end of the main surface 5a of the insulating base 5 and on the main surface 5a and the side surface of the insulating base 5. The opening 3 can be formed.

  In the manufacturing method of the wiring board 1 according to the present embodiment, the recess 3 cut in the third step is opened only on the main surface 5a side of the base body 17 in the second step. Therefore, when the plating 9 is formed on the side surface portion of the recess 3, the edge effect is easily affected. However, in the method of manufacturing the wiring board 1 according to the present embodiment, the plating solution is irradiated with ultrasonic waves, and is oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis of the recess 3. The plating 9 is formed on the surface of the wiring conductor 7 located on the side surface of the recess 3. Therefore, the variation in the thickness of the plating 9 formed on the side surface of the recess 3 cut in the third step can be reduced.

  Next, a method for manufacturing the wiring board 1 according to the second embodiment of the present invention will be described.

  The manufacturing method of the wiring board 1 according to the present embodiment prepares a board including the insulating base 5 having the recess 3 on the main surface 5a and the wiring conductor 7 disposed on the side surface of the recess 3. A first step and a second step of forming the Ni electrolytic plating 9 on the wiring conductor 7 by immersing the insulating substrate 5 in a plating solution containing Ni and energizing the wiring conductor 7. I have. The plating solution contains nickel sulfamate as a main component and sulfur is further added.

  Although nickel sulfamate contains sulfur, in the manufacturing method of the wiring board 1 according to the present embodiment, a plating solution to which sulfur is further added is used in addition to the sulfur contained in the nickel sulfamate. Yes.

  As in the method for manufacturing the wiring substrate 1 according to the first embodiment, the plating solution is irradiated with ultrasonic waves so that it is oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis. Although the plating 9 can be formed on the surface of the wiring conductor 7 located on the side surface of the concave portion 3, as in the manufacturing method of the wiring board 1 according to the present embodiment, the main component is nickel sulfamate and further sulfur. The surface of the wiring conductor 7 positioned on the side surface of the recess 3 is also provided with the plating 9 oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis of the recess 3 by using a plating solution to which is added Can be formed on top.

  Thus, also by the manufacturing method of the wiring board 1 according to the present embodiment, the plating 9 oriented in the (1, 1, 0) direction from the side surface of the recess 3 toward the central axis of the recess 3 is positioned on the side surface of the recess 3. Since it can be formed on the surface of the wiring conductor 7 to be formed, variation in the thickness of the plating 9 in the recess 3 can be reduced.

  Similarly to the manufacturing method of the wiring substrate 1 according to the first embodiment, the recess 3 formed on the main surface 5a of the insulating base 5 is located at the opening portion rather than the inner diameter at the bottom surface parallel to the main surface 5a. It is preferable that the inner diameter is large. When the concave portion 3 is formed in this way, as already shown, the thickness of the plating 9 in the portion near the bottom of the concave portion 3 and the thickness of the plating 9 in the portion near the opening of the concave portion 3 are varied. This is because can be made smaller.

  Next, the electronic device 19 according to an embodiment of the present invention will be described.

  As shown in FIG. 7, the electronic device 19 of the present invention is disposed on the wiring board 1 typified by the above embodiment and the back surface 5 b of the wiring board 1, and is electrically connected to the wiring conductor 7. An electronic component 21 and a lid body 23 that seals the electronic component 21 are provided. The electronic component 21 in this embodiment is electrically connected to the wiring conductor 7 via the surface conductor 11 and the internal conductor 13.

  Since the electronic device 19 according to the present embodiment includes the wiring substrate 1 typified by the above-described embodiment, the variation in the thickness of the plating 9 in the recess 3 can be reduced. Therefore, since the bonding property between the external wiring and the plating 9 is improved, the electronic device 19 with high reliability can be obtained.

  The lid 23 may be disposed on the main surface 5a of the base body 17 so that the electronic component 21 can be sealed. For example, a plate-shaped member whose main component is a ceramic material such as alumina ceramics and mullite ceramics, a plate-shaped member whose main component is glass, a metal member, and silicon can be used.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Wiring board 3 ... Concave 5 ... Insulating base | substrate 5a ... Main surface 5b ... Back surface 7 ... Wiring conductor 9 ... Plating 11 ... Surface conductor 13 ... Internal conductor 15 ... via conductor 17 ... base 19 ... electronic device 21 ... electronic component 23 ... lid

Claims (6)

An insulating substrate having a recess on the main surface;
A wiring conductor disposed on a side surface of the recess;
A wiring board provided on the wiring conductor and comprising Ni as a main component and oriented in a (1, 1, 0) direction from a side surface of the concave portion toward a central axis of the concave portion.   The wiring substrate according to claim 1, wherein the concave portion is located at an end portion of the main surface of the insulating base and is open to a main surface and a side surface of the insulating base.   The wiring substrate according to claim 1, wherein the concave portion has an inner diameter at an opening portion larger than an inner diameter at a bottom surface parallel to the main surface. A first step of preparing a substrate including an insulating base having a recess on a main surface and a wiring conductor disposed on a side surface of the recess;
And a second step of forming Ni electrolytic plating on the wiring conductor by immersing the insulating base in a plating solution containing Ni and energizing the wiring conductor. Because
In the second step, a method of manufacturing a wiring board, wherein the plating solution is irradiated with ultrasonic waves. A first step of preparing a substrate including an insulating base having a recess on a main surface and a wiring conductor disposed on a side surface of the recess;
And a second step of forming Ni electrolytic plating on the wiring conductor by immersing the insulating base in a plating solution containing Ni and energizing the wiring conductor. Because
The method for manufacturing a wiring board, wherein the plating solution contains nickel sulfamate as a main component and sulfur is further added.   An electronic device comprising: the wiring board according to claim 1; an electronic component disposed on a back surface of the wiring substrate and electrically connected to the wiring conductor; and a lid for sealing the electronic component. apparatus.

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