JP2003283068A - Multiple wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of a prior art multiple wiring board that the loss of a high frequency signal due to the conduction pattern is increased when the position for making a division groove is shifted. <P>SOLUTION: A plurality of wiring board regions sectioned by division lines 6 are formed on the major surface of a base board while being arranged vertically and horizontally and a plurality of wiring patterns 2 are formed between adjacent wiring board regions across the division line 6. In such a multiple wiring board, the wiring pattern 2 consists of a first wiring pattern 1 becoming a ground line G on the both wiring board region sides and a second wiring pattern 2 becoming a signal line S on one hand and becoming the ground line G on the other hand, and a through hole 7' consists of a first through hole 7b' penetrating the first wiring pattern 1 and a second through hole 7a' penetrating the second wiring pattern 2 and having a cross-sectional area smaller than that of the first through hole 7b'. Since excess exposure of the signal line is reduced extremely, transmission loss of a high frequency signal can be reduced. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-cavity wiring board for dividing and manufacturing a large number of wiring boards from one mother board. 2. Description of the Related Art FIG. 6 is an exploded perspective view of a conventional wiring board on which a semiconductor element operated by a high-frequency signal is mounted, which is used for a leadless chip carrier (LCC) type package. As shown in the figure, this LCC type wiring board is generally made of a ceramic such as alumina (Al ₂ O ₃ ) ceramic or aluminum nitride (AlN) ceramic having a mounting portion 11 d on which a semiconductor element 14 is mounted. The base body 11 includes a plurality of stacked substrates. The first ceramic substrate 11a of the base 11
A groove is provided on the side surface of the second ceramic substrate 11b, and a conductive portion made of an electrolytic plating layer or the like is provided on the inner surface of the groove. An external mounting board (not shown) and a wiring pattern 12 formed inside the wiring board and having a signal (S) line and a ground (G) line formed thereon are connected by electrode pads (external connection terminals) 17. It is electrically connected.
The electrode pad 17 is formed of a conductive portion formed on the inner surface of the groove. The third ceramic substrate 11c of the base 11
In order to increase the bonding area with the lid 13 and to strengthen the bonding of the lid 13 to the base 11, grooves such as the first ceramic substrate 11a and the second ceramic substrate 11b Is not formed, and the third ceramic substrate 11
c has a function as a so-called seal ring. [0005] Since such a wiring board is very small, a single ceramic green sheet serving as a mother board is provided with a dividing groove, a plurality of these are laminated and sintered to obtain ceramics, and then subjected to electrolytic plating. Then, it is preferable to manufacture the semiconductor device by so-called multi-cavity manufacturing in which individual wiring boards are divided by dividing grooves. The production by multi-cavity production is much easier than the lamination and sintering of the divided individual ceramic green sheets, and the cost can be reduced. For this reason, the base 11 is made of a first ceramic substrate 11 shown in the respective partial enlarged plan views of FIGS.
a, second ceramic substrate 11b, third ceramic substrate
The ceramic green sheets for 11c are laminated and sintered to form ceramics, then subjected to electrolytic plating, and then divided by dividing grooves 16 to produce a substrate 11 for a wiring board. As shown in a partially enlarged plan view of FIG. 7, a mounting portion 11d for a semiconductor element 14 and a through hole 17 'are provided on a ceramic green sheet serving as a first ceramic substrate 11a. A dividing groove 16 is provided so as to cross over a substantially central portion of the through hole 17 '. Further, as shown in a partially enlarged plan view of FIG. 8 and a main part plan view of FIG. 10, a ceramic green sheet serving as the second ceramic substrate 11b has a dividing groove 16 and a through hole (opening) at a central portion. 11b ') and a substantially central portion is formed so as to straddle the dividing groove 16, and the through hole 1 which forms the electrode pad 17 when divided into individual wiring boards.
7 'is provided. Further, the dividing groove 16 of the through hole 17 '
The wiring pattern 12 is formed so as to be connected to both sides. Further, in order to apply electrolytic plating to the inner peripheral surface of these through holes 17 ′ and the wiring pattern 12, conductive patterns 15 are formed between the through holes 17 ′ so as to cross the dividing groove 16 in a zigzag manner. As shown in a partially enlarged plan view of FIG. 9, the ceramic green sheet serving as the third ceramic substrate 11c is provided with a slightly larger through hole 11b 'at the center of FIGS. The through hole 11 c ′ is formed together with the dividing groove 16. [0010] Such an electrode pad 17, wiring pattern 12
The conductive pattern 15 is made of metallized metal powder such as tungsten or copper. For example, a metal paste composed of a tungsten powder, an organic solvent, and a binder is applied to the surface (including the groove surface) of each ceramic green sheet serving as the base 11.
Is formed by printing and applying a predetermined pattern on the substrate. The through hole of the first ceramic substrate 11a
The electrolytic plating on the inner peripheral surface of 17 ′ is performed when the first ceramic substrate 11a and the second ceramic substrate 11b are laminated.
This is performed by bringing the respective through holes 17 'into contact and conducting. Thus, the conductive pattern for electrolytic plating
15 can electrically connect all the through holes 17 ′ and the wiring pattern 12 during electrolytic plating, and furthermore,
Since the conductive pattern 15 is cut at the divided surface when the wiring pattern is divided into the individual wiring boards by the dividing groove 16, the wiring patterns 12 are not electrically short-circuited. In such a base 11, a semiconductor element 14 is bonded to a mounting portion 11d thereof with a low melting point brazing material such as gold (Au) -germanium (Ge) or a resin adhesive, and a semiconductor element 14 is formed on the wiring pattern 12. The electrodes of the element 14 are electrically connected via bonding wires (not shown). Furthermore, on the upper surface of the base 11, a metal material such as an iron (Fe) -nickel (Ni) -cobalt (Co) alloy or an iron (Fe) -nickel (Ni) alloy, or a ceramic such as an alumina ceramic or an aluminum nitride ceramic is used. The lid 13 is joined by welding by seam welding or the like, or by bonding with a low melting point brazing material such as gold (Au) -tin (Sn) solder. Thus, a semiconductor device as a product in which the semiconductor element 14 is housed is obtained. Such a semiconductor device has its electrode pad
The semiconductor element 14 is electrically connected to an external mounting board via a low-melting point solder such as tin (Sn) -lead (Pb) solder via the 17 and exchanges high-frequency signals with the mounting board. [0015] However, in the conventional multi-cavity wiring board, the through hole and the wiring pattern 12 are not provided.
It is necessary to provide a conductive pattern in order to electrically connect the conductive patterns, and when divided into individual wiring boards, the cut ends of the conductive pattern remain as extending from the wiring pattern 12, so that the semiconductor element is particularly required. 14 operating frequency is GH
There has been a problem that the loss due to the detour transmission of the signal when the frequency is increased to the z band becomes very large. In the conventional multi-cavity wiring board, since the diameter of the through hole is almost the same, the exposed area of the through hole in which the signal (S) line is formed is particularly large, and the semiconductor element 14 There is a problem that the loss due to the detour transmission of the signal when the operating frequency is increased to the GHz band becomes very large. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to improve the transmission characteristics of a high-frequency signal transmitted through a signal line of a wiring pattern by using a high-frequency signal of a semiconductor element. It is an object of the present invention to provide a wiring board capable of improving the operability of the wiring board. According to the present invention, there is provided a multi-cavity wiring board, in which a plurality of substantially rectangular wiring board regions divided by dividing lines are vertically and horizontally arranged on a main surface of a mother substrate made of ceramics. A plurality of wiring patterns having a plurality of wiring patterns formed across the division groove between adjacent wiring substrate regions, and having a through-hole penetrating the wiring pattern across the division groove. In the wiring board, the wiring pattern is a first wiring pattern that is a ground wiring on both of the adjacent wiring board regions, and a signal wiring on one of the adjacent wiring substrate regions,
A second wiring pattern serving as a ground wiring on the other wiring board region side, wherein the through-hole includes a first through-hole passing through the first wiring pattern;
And a second through hole having a smaller cross-sectional area than the first through hole, penetrating the wiring pattern. According to the multi-cavity wiring board of the present invention, according to the above configuration, the wiring pattern is formed such that the first wiring pattern, which is grounded on both adjacent wiring board regions, is connected to one of the adjacent ones. Since the second wiring pattern is used as a signal wiring on the wiring board area side and is used as a ground wiring on the other wiring board area side, a part of the ground wiring is made conductive for electrolytic plating. Since all the ground wiring and signal wiring can be made conductive for electrolytic plating, there is no need to pull out the lead wiring (conductive pattern) for conductivity on the wiring board, so an extra wiring pattern (conductive pattern) is used. Transmission loss of a high-frequency signal propagating through a signal wiring pattern can be reduced. Further, in the above configuration, the through-hole penetrating the wiring pattern over the division groove may include a first through-hole penetrating the first wiring pattern and a second through-hole penetrating the second wiring pattern. Since the second through-hole having a smaller cross-sectional area than the first through-hole has a very small exposure of extra signal wiring, the transmission loss of the high-frequency signal propagating through the signal wiring pattern is further reduced. Can be smaller. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A multi-cavity wiring board according to the present invention will be described in detail below. FIG. 1 is an exploded perspective view showing an example of an embodiment of an individual wiring board manufactured by dividing the multi-cavity wiring board of the present invention, and FIGS. 2 to 4 show respective ceramic green sheets before lamination. Partially enlarged plan view,
FIG. 5 is a plan view of an essential part showing an example of forming a conductive pattern in the multi-cavity wiring board of the present invention. In these figures, 1 is a base and 2 is a wiring pattern. A wiring board is formed by the base 1 and the wiring pattern 2,
The semiconductor device is formed by hermetically sealing the semiconductor element 4 with the lid 3 and the like. Such individual wiring boards are obtained by dividing a multi-piece wiring board in which a wiring board area to be a wiring board after being divided into one mother board made of ceramics is divided by a dividing groove and arranged vertically and horizontally along a dividing line. It is produced by dividing. The base 1 has a concave portion on the upper surface, and a groove which becomes an electrode pad 7 by electrolytic plating on an inner peripheral surface is provided on an outer side surface thereof. For example, various types of materials such as alumina ceramics and aluminum nitride ceramics are provided. Consists of ceramics. Further, a mounting portion 1d for mounting and fixing the semiconductor element 4 on the bottom surface of the concave portion of the base 1 is provided. Such a base 1 functions as a mounting and fixing member for the semiconductor element 4, and a material for the mother substrate made of ceramics serving as the base 1 is appropriately selected according to the electrical characteristics of the semiconductor element 4. If the substrate 1 is made of, for example, alumina ceramics, it is manufactured as follows. First, a paste is prepared by adding an organic binder, a solvent, and the like to raw material powder such as aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), magnesium oxide (MgO), and calcium oxide (CaO). The paste is applied to a doctor blade method, a calendar roll method, or the like to form a ceramic grease of one or a plurality of sheets to form the first ceramic substrate 1a, the second ceramic substrate 1b, and the third ceramic substrate 1c. Make a sheet. In these ceramic green sheets, if necessary, the through holes 7 'and the through holes 1 serving as recesses for accommodating the semiconductor elements 4a provided in the central portions of the respective wiring board regions.
A punching process for forming b ′ and 1c ′ is performed, and thereafter, molybdenum (Mo) -manganese (Mn) or tungsten (Mn) is formed on the portion to be the wiring pattern 2 or the conductive pattern 5 or on the inner peripheral surface of the through hole 7 ′. Print and apply a metal paste such as W). Then, these are laminated and about 1600 ° C
It is produced by sintering at a temperature of As shown in a partially enlarged plan view of FIG. 2, a dividing groove 6 is formed on one main surface of the first ceramic green sheet serving as the first ceramic substrate 1a of the substrate 1.
Substantially rectangular wiring board regions, such as rectangles, are vertically and horizontally arranged. In this wiring board area, the semiconductor element 4
Is provided. Further, a through hole 7 ′ is provided on the line of the division groove 6. That is, the division groove 6 is provided so as to cross over a substantially central portion of the through hole 7 '. The through holes 7 ′ are formed at similar locations on the dividing groove 6 between the respective wiring board regions in order to form a large number of wiring boards having the same configuration. As shown in the partial enlarged plan view of FIG. 3 and the main part plan view of FIG. 5, the first ceramic green sheet serving as the second ceramic substrate 1b of the base 1 has a first main surface. A through-hole 1b 'for surrounding the semiconductor element 4 is formed at the center, which is defined by the dividing grooves 6 corresponding to the dividing grooves 6 on the ceramic green sheet of FIG. The array is formed. In each wiring board region, a through hole 7 ′ is formed on the division groove 6. That is, the division groove 6 is provided on the second ceramic green sheet so as to cross over substantially the center of the through hole 7 ′ of the second ceramic green sheet. When forming the wiring pattern 2 extending from the through hole 7 'to the through hole 1b' side of the second ceramic green sheet, the wiring pattern 2 for signals [signal (S)] is grounded in each wiring board region. [Ground (G)]
And the wiring patterns 2 are alternately arranged, for example. In this case, if there is no through hole 7 ', the wiring pattern 2 is formed across the dividing groove 6 between the wiring board regions adjacent to each other. The through hole 7 'is formed between the first through hole 7b' penetrating the first wiring pattern 2 which is the ground wiring G on both adjacent wiring board regions, and the adjacent one of the wiring boards. A second through hole, which has a smaller cross-sectional area than the first through hole 7b ', penetrates through the second wiring pattern 2, which is a signal wiring S on the area side and a ground wiring G on the other wiring board area side. The hole 7a 'is formed. That is, with respect to the second through-hole 7a ', the signal wiring pattern 2 is formed on one side and the ground wiring pattern 2 is formed on the other side. It is important to arrange the wiring pattern 2 (signal wiring S) and the wiring pattern 2 for grounding (ground wiring G) in combination. By adopting such a combination, it is not necessary to pull out the lead-out wiring (conductive pattern) for wiring between the wiring patterns 2 adjacent to the wiring board, so that an extra wiring pattern 2 is added. Accordingly, the transmission loss of the high-frequency signal propagating through the signal wiring pattern 2 can be reduced. Further, since the second through-hole 7a 'has a smaller cross-sectional area than the first through-hole 7b', the exposure of the extra signal wiring S becomes extremely small. The transmission loss of the high-frequency signal propagating through the wiring pattern 2 can be further reduced. The signal line is a wiring pattern 2
And a conductor of the electrode pad 7 connected thereto and a transmission path of a high-frequency signal. The ground line is a conductive path of a ground potential formed by the wiring pattern 2 and the conductor of the electrode pad 7 connected thereto. It is. The configuration of the wiring pattern 2 itself is as follows.
Although there is no particular distinction between a signal line and a ground line, it is better to form ground lines on both the left and right sides of the signal line to improve the impedance characteristics. As shown in FIG. 4, the main surface of the third ceramic green sheet serving as the third ceramic substrate 1c is divided by division grooves 6 corresponding to the division grooves 6 on the second ceramic green sheet. In addition, a frame-shaped substrate region having a rectangular outer shape in which a through-hole 1c 'is formed in the center portion is arranged vertically and horizontally. As shown in the partial enlarged plan view of FIG. 4, a through hole 1c 'having an opening width slightly larger than that of the through hole 1b' of FIGS. 3 and 5 is formed. This is because, as shown in FIG. 1, the concave portion of the base body 1 is gradually narrowed downward. The top surface of the third ceramic substrate 1c is covered with a lid 3 for sealing the semiconductor element 4 by welding such as seam welding or a low melting point solder such as gold (Au) -tin (Sn) solder. It functions as a seal member that is firmly joined by bonding with materials, a so-called seal ring. Further, the width of the frame is set to an appropriate size so as to maintain the bonding strength. The electrolytic plating on the inner peripheral surface of the through hole 7 ′ of the first ceramic substrate 1 a is performed when the first ceramic substrate 1 a and the second ceramic substrate 1 b are laminated.
This is performed by bringing the respective through holes 7 'into contact and conducting. Further, when performing electrolytic plating having excellent corrosion resistance such as nickel (Ni) plating or gold (Au) plating after lamination and sintering, all the through holes 7 ′ and the wiring patterns 2 are electrically connected. However, when the wiring patterns are divided into individual wiring boards, the through holes 7 ′ are cut at the divided surfaces, so that the respective wiring patterns 2 are not electrically short-circuited. Thus, the multi-cavity wiring board of the present invention is provided with the through holes 1 b ′, 1
c ', a groove provided on the outer side surface of the base 1, and formed as a groove formed by dividing the through hole 7' in the vertical direction and serving as an electrode pad 7 for making an electrical connection to the outside; 2nd, 3rd
Through holes 7 'provided in each ceramic green sheet
The split groove 6 traversing the substantially central portion of the upper end opening of the second ceramic green sheet and the split groove 6 of the through hole 7 ′ provided in the second ceramic green sheet are joined on both sides to establish electrical connection with the semiconductor element 4. It has a structure in which a wiring board region having a wiring pattern 2 to be performed is formed vertically and horizontally. In the case of the example shown in FIG. 1, each wiring board is provided with through holes 1b 'and 1c', a through hole 7 ', a dividing groove 6, and a wiring pattern 2; After laminating and sintering the ceramic green sheets and subjecting them to electrolytic plating, the first, second, and third ceramic green sheets are divided by corresponding division grooves 6 so as to overlap in the vertical direction. . As a result, a concave portion is formed on the upper surface of the wiring substrate, and the base 1 having the mounting portion 1d on which the semiconductor element 4 is mounted is provided on the bottom surface of the concave portion. That is, a first ceramic substrate 1a having a mounting portion 1d on which the semiconductor element 4 is mounted on the upper surface, and a first ceramic substrate 1a laminated on the upper surface of the first ceramic substrate 1a to electrically connect the semiconductor element 4 to the outside. Frame-shaped second ceramic substrate 1 to be performed
and a frame-shaped third ceramic substrate 1c laminated on the upper surface of the second ceramic substrate 1b and joined to the lid 3 for sealing the semiconductor element 4 on the upper surface. It becomes. Further, the individual wiring boards formed by the multi-cavity wiring board of the present invention are not limited to those having recesses formed on the upper surface of the base 1 as shown in FIG. A cap-shaped lid may be joined to the portion. As described above, a plurality of ceramic green sheets are laminated, sintered and electrolytically plated, and each of the ceramic substrates 1a, 1b and 1c is divided by the dividing groove 6 to form the base 1
After that, the semiconductor element 4 is placed on the mounting portion 1d with gold (Au) −
The semiconductor element 4 is mounted and fixed via a low melting point brazing material such as germanium (Ge) or a resin adhesive, and the electrode of the semiconductor element 4 is electrically connected to the wiring pattern 2 via a bonding wire. Then, iron (Fe) -nickel (Ni)-
The cover 3 made of a metal material such as a cobalt (Co) alloy or an iron-nickel alloy, or a ceramic such as an alumina ceramic or an aluminum nitride ceramic is welded by seam welding or the like or gold (Au) -tin (Sn) solder or the like. The semiconductor device is joined by bonding with a low melting point brazing material, and becomes a semiconductor device as a product in which the semiconductor element 4 is housed. Such a semiconductor device is inexorably connected to an external mounting board via the electrode pad 7 by using a low-melting point solder such as tin (Sn) -lead (Pb) solder. The semiconductor element 4 is operated by transmitting and receiving signals. It should be noted that the present invention is not limited to the above-described embodiment, and that various changes may be made without departing from the scope of the present invention. For example, the present invention is also applied to a wiring board for forming an optical semiconductor element housing package for housing an optical element such as a semiconductor laser (LD) which is a kind of light emitting element operated by a high frequency signal. it can. As the insulating material for forming the mother board and the conductive material for forming the wiring pattern 2, various insulating materials and conductive materials that can be used for a multi-cavity wiring board are used in addition to ceramics and metal paste. be able to. According to the multi-cavity wiring board of the present invention,
A plurality of substantially rectangular wiring board regions separated by dividing lines are formed vertically and horizontally on the main surface of the mother substrate made of ceramics, and a plurality of wiring board regions formed across the dividing groove between the adjacent wiring board regions. With the wiring pattern,
In a multi-cavity wiring board in which a through-hole penetrating the wiring pattern over the division groove, the wiring pattern is a ground wiring on both adjacent wiring board regions. And a signal wiring on one of the adjacent wiring substrate regions and a ground wiring on the other wiring substrate region.
Since a part of the ground wiring is made conductive for electrolytic plating, all the ground wiring and signal wiring can be made conductive for electrolytic plating. It is not necessary to pull out the lead-out wiring (conduction pattern), so that the transmission loss of the high-frequency signal propagating through the signal wiring pattern due to the extra wiring pattern (conduction pattern) can be reduced. Further, according to the multi-cavity wiring board of the present invention, in the above structure, the through-holes pass through the first wiring pattern and the second through-hole. Since the second through-hole having a smaller cross-sectional area than the first through-hole has a very small exposure of extra signal wiring, transmission of a high-frequency signal propagating through a signal wiring pattern is very small. Loss can be further reduced. As described above, according to the present invention, it is possible to improve the operability of a semiconductor element by a high-frequency signal by making the transmission characteristics of a high-frequency signal transmitted through a signal line of a wiring pattern smooth. It is possible to provide a wiring board that can be used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing an example of an embodiment of an individual wiring board manufactured by dividing a multi-piece wiring board of the present invention. FIG. 2 is a partially enlarged plan view showing a first ceramic green sheet before lamination as a first ceramic substrate in the multi-cavity wiring board of the present invention. FIG. 3 is a partially enlarged plan view showing a second ceramic green sheet before lamination as a second ceramic substrate in the multi-cavity wiring board of the present invention. FIG. 4 is a partially enlarged plan view showing a third ceramic green sheet before lamination as a third ceramic substrate in the multi-cavity wiring board of the present invention. FIG. 5 is a plan view of a main part of a second ceramic green sheet showing an example of formation of a wiring pattern on a multi-cavity wiring board of the present invention. FIG. 6 is an exploded perspective view showing a conventional wiring board. FIG. 7 is a partially enlarged plan view showing a ceramic green sheet before lamination as a first ceramic substrate in a conventional multi-cavity wiring board. FIG. 8 is a partially enlarged plan view showing a ceramic green sheet before lamination as a second ceramic substrate in a conventional multi-cavity wiring board. FIG. 9 is a partially enlarged plan view showing a ceramic green sheet before lamination as a third ceramic substrate in a conventional multi-cavity wiring board. FIG. 10 is a plan view of a main part of the ceramic green sheet showing the conduction pattern of FIG. 8; [Description of Signs] 1: Base 1a: First ceramic substrate 1b: Second ceramic substrate 1c: Third ceramic substrate 2: Wiring pattern 3: Lid 4: Semiconductor element 6: Dividing groove 7 ': Through hole 7a ': second through hole penetrating the second wiring pattern 7b': first through hole penetrating the first wiring pattern

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Claims (1)

Claims: 1. A plurality of substantially rectangular wiring board regions separated by dividing lines are formed vertically and horizontally on a main surface of a mother substrate made of ceramics, and the wiring board regions are arranged between adjacent wiring board regions. In a multi-cavity wiring board having a plurality of wiring patterns formed across the dividing groove and having a through-hole penetrating the wiring pattern across the dividing groove, the wiring patterns are adjacent to each other. A first wiring pattern that is a ground wiring on both of the wiring board regions;
A second wiring pattern that is used as a signal wiring on one of the adjacent wiring substrate regions and a ground wiring on the other wiring substrate region; The first to penetrate
And a second through-hole having a smaller cross-sectional area than the first through-hole, penetrating through the second wiring pattern.