JP3554189B2 - Multi-cavity ceramic wiring board - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multi-cavity ceramic wiring board in which a large number of wiring boards for mounting electronic components such as a semiconductor element and a crystal unit are arranged vertically and horizontally on a wide-area ceramic substrate.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a wiring board for mounting electronic components such as a semiconductor element and a quartz oscillator has a lower surface through a side surface from a central portion of an upper surface of a substantially flat insulating base made of a ceramic material such as an aluminum oxide sintered body. , A plurality of wiring conductors made of a metallized metal powder of a high melting point such as tungsten or molybdenum to which the electrodes of the electronic component are connected.
[0003]
According to this wiring board, the electronic component is mounted on the central portion of the upper surface of the insulating base, and each electrode of the electronic component is electrically connected to the wiring conductor via solder or a bonding wire. A potting resin or a bowl-shaped metal lid is attached to the upper surface of the electronic device so as to cover the electronic component, and the electronic component is hermetically sealed to provide an electronic device as a final product.
[0004]
By the way, such a wiring board has become extremely small with a size of about several mm square in accordance with recent demands for miniaturization of electronic devices, and facilitates handling of a large number of wiring boards. In order to efficiently manufacture wiring boards and electronic devices, a so-called multi-cavity ceramic in which a large number of wiring boards are simultaneously and intensively obtained from one large-area ceramic mother board. It is manufactured in the form of a wiring board.
[0005]
As shown in the top view of FIG. 2, for example, such a multi-piece ceramic wiring board is provided with a large number of wiring board parts serving as wiring boards at the center of a ceramic substrate 11 serving as a substantially rectangular large-area mother board. 12 has a product region 11a (region surrounded by a two-dot chain line in FIG. 2) arranged and formed in a matrix, and has a frame-shaped discard margin region 11b surrounding the product region 11a on its outer peripheral portion. ing. The product area 11a is an area for forming the wiring board section 12, and the disposal area 11b is for facilitating the handling of a multi-piece ceramic wiring board.
[0006]
In the multi-cavity ceramic wiring board, a dividing groove 13 for dividing the ceramic substrate 11 into a large number of wiring boards is formed at the boundary of each wiring board portion 12 formed on the ceramic substrate 11 by, for example, laser processing. A plurality of wiring boards can be obtained by dividing the wiring board portion 12 from the ceramic substrate 11 along the dividing grooves 13 at a predetermined depth on the upper surface and / or the lower surface of the substrate 12. ing.
[0007]
In the multi-cavity ceramic wiring board, a substantially square through-hole 14 is formed at, for example, an intersection of the dividing groove 13 in the product region 11a of the ceramic substrate 11 so that each apex thereof coincides with the dividing groove 13. .
[0008]
In each of the wiring board portions 12, a plurality of metallized wiring conductors 15 extending from the upper surface to the lower surface via the inner surface of the through hole 14 are respectively attached.
[0009]
The through-hole 14 provides a lead-out path for leading the wiring conductor 15 in each wiring board unit 12 from the upper surface to the lower surface of the ceramic substrate 11, and when the ceramic substrate 11 is divided into each wiring board unit 12, Or fix the legs provided on the cover when attaching the metal cover to each wiring board.
[0010]
In the multi-cavity ceramic wiring board, the electronic components are mounted on the respective wiring board portions 12 and the respective electrodes of the electronic components are electrically connected to the wiring conductors 15. By sealing with a lid and finally dividing the ceramic substrate 11 along the dividing groove 13, a large number of electronic devices can be manufactured simultaneously and intensively.
[0011]
In this multi-cavity ceramic wiring board, an automatic machine is generally used to mount electronic components or attach a potting resin or a metal lid to each wiring board portion 12 formed on the ceramic substrate 11. . For example, one side of the long side of the ceramic substrate 11 has been used as a reference side for mounting and positioning for positioning electronic components, potting resin, and the like on each wiring board unit 12 by an automatic machine.
[0012]
[Problems to be solved by the invention]
The multi-cavity ceramic wiring board as described above is generally manufactured by a conventionally known ceramic green sheet method.
[0013]
More specifically, for example, first, a ceramic green sheet serving as a ceramic substrate 11 is prepared, and a through hole serving as a through hole 14 is formed in a region serving as a product region 11a of the ceramic green sheet by a conventionally known punching method. Formed. Next, a high-melting metal paste such as tungsten or molybdenum serving as a wiring conductor 15 is formed from the upper surface of each region of the ceramic green sheet serving as the wiring board portion 12 to the inner surface and the lower surface of the through hole 14 serving as the wiring conductor 15. A predetermined pattern is printed and applied by using a screen printing method. Then, the ceramic green sheet and the metal paste are fired at a high temperature of about 1600 ° C. in a reducing atmosphere to obtain a ceramic substrate 11 having a large number of wiring board portions 12 formed in a product region 11a. It is manufactured by forming a dividing groove 13 at the boundary of the wiring board portion 12 by, for example, a laser.
[0014]
By the way, in the multi-piece ceramic wiring board manufactured by the ceramic green sheet method, firing shrinkage occurs when firing the ceramic green sheet to be the ceramic substrate 11. Although a large number of through holes serving as the through holes 14 are formed in the portion serving as the product region 11a of the ceramic green sheet, the through holes are not formed in the portion serving as the disposal region 11b of the ceramic green sheet. The product region 11a shrinks by firing more than the waste allowance region 11b. As a result, a portion corresponding to the product region 11a on each outer peripheral side of the ceramic substrate 11 has a shape recessed toward the center of the ceramic substrate 11. As a result, each side of the substantially rectangular ceramic substrate 11 is curved.
[0015]
When each side of the ceramic substrate 11 is curved in this way, when positioning one electronic component, a potting resin, a metal cover, or the like on each wiring board portion 12 of the ceramic substrate 11 with an automatic machine using one side as a reference side. The electronic component, the potting resin, the metal lid, and the like cannot be accurately positioned with respect to each wiring board portion 12, and as a result, the electrodes of the electronic component and the wiring conductor 15 of the wiring board portion 12 are electrically normal. Or the electronic component cannot be hermetically sealed with a potting resin or a metal lid.
[0016]
The present invention has been devised in view of the conventional drawbacks, and an object of the present invention is to provide an electronic component, a potting resin, a metal, and the like for each of the wiring conductors of a large number of wiring boards arranged and formed on a ceramic substrate serving as a mother board. The lid and other parts are accurately positioned using an automatic machine, and the electronic components and the wiring conductors on the wiring board can be electrically connected properly and the electronic components are sealed with a potting resin or metal lid with high airtightness. It is another object of the present invention to provide a multi-cavity ceramic wiring board capable of performing the above-mentioned steps.
[0017]
[Means for Solving the Problems]
A multi-cavity ceramic wiring board according to the present invention is a substantially square product area having a side parallel to the reference side disposed at the center of a substantially square plate-shaped ceramic substrate having one side as a reference side for mounting and positioning. A plurality of wiring board portions each of which is divided by a dividing groove, a through-hole is formed in a predetermined pattern on the dividing groove, and a wiring conductor is attached thereto, and the reference is made with respect to the product area. A dummy through-hole is formed in an extended region in a direction parallel to the side in the same pattern as the through-hole in a plan view. Further, in the multi-cavity ceramic wiring board of the present invention, preferably, the ceramic substrate has a rectangular shape having the reference side as a long side, and the dummy through-hole is formed only in the extension region. It is.
[0018]
According to the multi-cavity ceramic wiring board of the present invention, of the disposal area formed on the outer peripheral portion of the ceramic substrate serving as the motherboard, the reference side with respect to the product area formed in the center of the ceramic motherboard. Since dummy through-holes having the same pattern as the through-holes provided in the product area are formed in the extended area in the parallel direction, the firing shrinkage in the direction orthogonal to the reference side of the mother board is substantially reduced in each part. As a result, the reference side of the ceramic substrate is prevented from bending, and electronic parts, potting resin, metal lids, etc. are applied to the wiring conductors of a large number of wiring boards using an automatic machine using the reference side. The electronic components can be electrically connected normally to the wiring conductors of the wiring board, and the electronic components can be hermetically sealed with a potting resin or a metal lid.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a multi-cavity wiring board of the present invention will be described with reference to the accompanying drawings.
[0020]
FIG. 1 is a top view showing an example of an embodiment of a multi-cavity ceramic wiring board according to the present invention, wherein 1 is a ceramic substrate serving as a mother board of the multi-cavity ceramic wiring board, and 2 is a wiring board unit.
[0021]
The ceramic substrate 1 is made of an electrically insulating material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon nitride sintered body, a silicon carbide sintered body, or a glass ceramic. It is a rectangular flat plate, and has a product region 1a in which a large number of wiring board portions 2 are arranged and formed at the center thereof, and a product region 1a (surrounded by a two-dot chain line in FIG. Area) is surrounded by a frame-shaped waste allowance area 1b.
[0022]
Then, one side of the ceramic substrate 1, for example, one of the upper and lower sides (the long side of the substantially rectangular substrate) in the figure in the example of FIG. 1 is used as a reference side G for mounting and positioning by the automatic machine. The product region 1a is arranged as a substantially rectangular region having a side parallel to the reference side G.
[0023]
When the ceramic substrate 1 is made of, for example, an aluminum oxide sintered body, a suitable organic binder and a solvent are added to and mixed with raw material powders of aluminum oxide, silicon oxide, calcium oxide, magnesium oxide, etc. to form a slurry. At the same time, a ceramic green sheet is obtained by forming the ceramic green sheet into a sheet shape by employing a well-known doctor blade method. Thereafter, the ceramic green sheet is subjected to an appropriate punching process, and at a temperature of about 1600 ° C. in a reducing atmosphere. It is manufactured by firing.
[0024]
A dividing groove 3 for dividing the ceramic substrate 1 into a large number of wiring substrate portions 2 is formed at the boundary between the wiring substrate portions 2 arranged and formed in the product region 1a of the ceramic substrate 1.
[0025]
The dividing groove 3 is formed at a predetermined depth on the upper surface and / or the lower surface of the ceramic substrate 1, and the ceramic substrate 1 is chocolate-breaked along the dividing groove 3 so that the ceramic substrate 1 is separated from each of the wiring board portions 2. Is divided into a number of wiring boards.
[0026]
The dividing groove 3 is formed by forming a groove of a predetermined depth on the upper surface and / or lower surface of the ceramic substrate 1 by a laser, or by forming a die or cutting on the upper surface and / or lower surface of the ceramic green sheet to be the ceramic substrate 1. It is formed by cutting a predetermined depth with a blade or the like.
[0027]
Also, on the dividing groove 3 in the product region 1a of the ceramic substrate 1, for example, at the intersection thereof, a predetermined pattern, in this example, a repetitive pattern of substantially square through holes, the through hole 4 has its vertex coincident with the dividing groove 3. It is formed in such a manner as to make it.
[0028]
The through-hole 4 provides a lead-out path for leading a wiring conductor 5 described later from the upper surface to the lower surface of each wiring board portion 2, and facilitates division when dividing the ceramic substrate 1 along the dividing groove 3. It acts to ensure the reliability or to fix the legs provided on the lid when attaching the metal lid to each wiring board.
[0029]
In addition, the through hole 4 is formed by punching, for example, a square through hole in a region to be the product region 1a of the ceramic green sheet to be the ceramic substrate 1 by a punching method, thereby forming the divided groove 3 in the product region 1a of the ceramic substrate 1. The vertices are formed at the intersections so that their vertices coincide with the division grooves 3.
[0030]
A wiring conductor 5 composed of a plurality of metallized wiring conductors and the like led out through the inner surface of the through hole 4 is formed on the ceramic substrate 1 in each wiring board portion 2 of the product region 1a from the upper surface to the lower surface.
[0031]
The wiring conductor 5 is made of, for example, a sintered metal powder of tungsten, molybdenum, copper, silver, or the like, and functions as a conductive path for electrically connecting an electronic component mounted on the wiring board 2 to the outside. Each electrode of the electronic component is electrically connected to the upper surface portion of the substrate portion 2 via electrical connection means such as solder or bonding wire, and the lower surface portion of the wiring substrate portion 2 is connected to the wiring conductor of the external electric circuit board. It is electrically connected.
[0032]
The wiring conductor 5 is formed by punching out a through hole to be a through hole 4 in a ceramic green sheet to be a ceramic substrate 1, and then forming an upper surface and a lower surface of a region to be each wiring board portion 2 of the ceramic green sheet and a through hole to be a through hole 4. A metal paste to be the wiring conductor 5 is printed and applied in a predetermined pattern on the inner surface of the hole by using a conventionally well-known screen printing method, and is fired together with the ceramic green sheet. 1 is formed so as to be led out from the upper surface to the lower surface through the inner surface of the through hole 4.
[0033]
When the wiring conductor 5 is made of a sintered tungsten powder, for example, the wiring conductor 5 and the metal paste are formed by adding and mixing an appropriate organic binder, a solvent, and the like to the tungsten powder to form a paste. Can be
[0034]
The ceramic substrate 1 has the same pattern as the through-holes 4 formed in the product region 1a in the extension region 1b ′ in the direction parallel to the reference side G with respect to the product region 1a. That is, the dummy through holes 6 are formed with substantially the same shape, the same size, and the same arrangement interval.
[0035]
The dummy through-holes 6 function to adjust the substrate shrinkage of the extended region 1b 'of the ceramic substrate 1, and make uniform firing shrinkage in the width direction of the ceramic substrate 1, that is, the direction orthogonal to the reference side G. Works.
[0036]
According to the multi-cavity ceramic wiring board of the present invention, the product area 1a is formed in the extension area 1b 'in the direction parallel to the reference side G with respect to the product area 1a. Since the dummy through holes 6 are formed in the same pattern as the formed through holes 4, the firing shrinkage in the width direction of the ceramic substrate 1 becomes uniform, and as a result, the reference side G of the ceramic substrate 1 is curved. There is no such thing as. Therefore, the electronic component, the potting resin, the metal cover, and the like can be accurately positioned and mounted on each wiring board portion 2 by an automatic machine using the reference side G as a mounting positioning reference. The electrodes and the wiring conductors 5 of the wiring board 2 are electrically and accurately connected, and the electronic components mounted on the wiring board 2 can be hermetically sealed with a potting resin, a metal cover, or the like. Become.
[0037]
The dummy through-holes 6 are formed by punching out the through-holes to be the through holes 4 in the ceramic green sheet to be the ceramic substrate 1 and simultaneously forming the through holes to be the dummy through-holes 6 in the ceramic green sheet disposal area 1b. In the extension area 1b 'in the direction parallel to the reference side G with respect to the product area 1a, punching is performed in a predetermined shape, a predetermined size, and a predetermined arrangement in the same manner as the predetermined pattern of the through holes 4 in the product area 1a. By doing so, the same pattern as the through holes 4 formed in the product region 1a is formed in the extension region 1b 'in the direction parallel to the reference side G with respect to the product region 1a of the ceramic substrate 1.
[0038]
Thus, according to the multi-cavity ceramic wiring board of the present invention, one of the long sides that are not curved is set as the reference side G for mounting positioning, and the electronic component is positioned and mounted on each wiring board unit 2 by an automatic machine. At the same time, each electrode of the electronic component is electrically connected to the wiring conductor 5 of each wiring board 2 through an electrical connection means such as solder or bonding wire, and then the electronic component is mounted on the upper surface of each wiring board 2. By positioning and attaching a potting resin or a metal lid so as to cover, and finally dividing the ceramic substrate 1 by chocolate breaking along the dividing grooves 3 formed therein, a large number of electronic devices can be accurately and easily manufactured. Will be manufactured simultaneously and intensively.
[0039]
It should be noted that the present invention is not limited to the above-described embodiments, and various changes and improvements may be made without departing from the spirit of the present invention.
[0040]
For example, in the above example, the through-hole and the dummy through-hole are both substantially square-shaped through-holes formed so that their vertices coincide with the intersections of the divided grooves, but the shapes of these through-holes and dummy through-holes are In addition to the square shape, various shapes such as a rectangular shape, a rhombic shape, a circular shape, an elliptical shape, a long hole shape, and the like may be used, and a combination thereof is formed on the dividing groove along the dividing groove. There may be. Also, the size of the through hole / dummy through hole may be a combination of several sizes.
[0041]
In addition, the area where the dummy through hole is provided is preferably an area extending to the end of the substrate in the above-described extended area, since it is most effective in preventing the reference side from being bent. Depending on the accuracy required and the range in which the accuracy is required, the region may be a region between the product region and the end of the substrate.
[0042]
【The invention's effect】
According to the multi-cavity ceramic wiring board of the present invention, a product area formed in a substantially square shape having a side parallel to the reference side at the center of the substantially square ceramic substrate having one side as a reference side for mounting and positioning. A predetermined pattern of through-holes are formed in the substrate, and a large number of wiring board portions are arrayed and formed. Since the dummy through-holes are provided in the same pattern as the through-holes provided in the regions, the amount of firing shrinkage in the direction orthogonal to the reference side of the ceramic substrate becomes substantially uniform in each portion corresponding to each region, and as a result, The reference side of the ceramic substrate is prevented from being curved. Therefore, the electronic component, the potting resin, the metal cover, and the like can be accurately positioned and mounted on each wiring board by an automatic machine using the reference side as a mounting positioning reference. It is possible to electrically accurately connect to the wiring conductor of the wiring board, and it is possible to hermetically seal the electronic components mounted on the wiring board with a potting resin, a metal cover, or the like.
[Brief description of the drawings]
FIG. 1 is a top view showing an example of an embodiment of a multi-cavity ceramic wiring board according to the present invention.
FIG. 2 is a top view showing an example of a conventional multi-cavity ceramic wiring board.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Ceramic board | substrate 1a ... Product area 1b ... Discard allowance area | region 1b '... Extension area G ... Reference side 2 ... Wiring board part 4 ... Through-hole 5 ... Wiring conductor 6 ... Dummy through hole

Claims (2)

In a substantially square-shaped product region having a side parallel to the reference side arranged at the center of a substantially square plate-shaped ceramic substrate having one side as a reference side for mounting and positioning, the divided part is divided by a dividing groove. A large number of wiring board portions formed with through holes formed in a predetermined pattern on the grooves and covered with wiring conductors are arranged, and the extended region in the direction parallel to the reference side with respect to the product region, A multi-cavity ceramic wiring board, wherein dummy through holes are formed in the same pattern as the through holes in a plane . The multi-cavity ceramic wiring board according to claim 1, wherein the ceramic substrate has a rectangular shape with the reference side as a long side, and the dummy through-hole is formed only in the extension region.

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