JP3894841B2 - Multiple wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multipiece wiring board wherein the wiring board regions formed in the center of a ceramic mother substrate are free from warp and deformation, electronic components can be normally mounted on each wiring board region, and further the ceramic mother substrate can be split into the individual wiring boards with accuracy. <P>SOLUTION: In the center of the ceramic mother substrate 1, a large number of wiring board regions 2 identical in shape are integrally formed in a matrix pattern with their orientation in alignment. Each of the wiring board regions 2 has a mounting portion on which electronic components 6 are to be mounted. Each of the wring board regions 2 has a plurality of wiring conductors 4 which extend from the upper face to the lower face thereof and are asymmetrical with respect of the center of the upper face thereof as viewed from above. In the peripheral area of the ceramic mother substrate 1, dummy wiring board regions 3 having dummy wiring conductors 9 which are in the same shape as the wiring conductors 4 are as viewed from above and turned through 180&deg; in the horizontal direction are formed. The dummy wiring board regions 3 are positioned adjacent to both ends of each row of the wiring board regions 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, a large number of wiring board regions, which are small-sized wiring boards for mounting electronic components such as semiconductor elements and crystal resonators, are formed by arranging a large number of vertical and horizontal arrays on a large-area ceramic mother board. The present invention relates to a wiring board.
[0002]
[Prior art]
A small ceramic wiring board for mounting an electronic component such as a semiconductor element or a crystal resonator includes, for example, a substantially rectangular flat plate-shaped ceramic substrate having a mounting portion on which an electronic component is mounted at the center of the upper surface, and the ceramic substrate. And a plurality of wiring conductors arranged so as to be led out from the upper surface to the lower surface through the inside or the side surface. The ceramic wiring board has electronic parts mounted on the ceramic base mounting portion, and each electrode of the electronic parts is electrically connected to the wiring conductor on the upper surface of the ceramic base. An electronic device as a product is obtained by fixing a sealing resin made of a thermosetting resin such as an epoxy resin so as to seal the electronic component, and a part led to the lower surface of the ceramic substrate by the wiring conductor is externally connected. An electronic component to be mounted is electrically connected to an external electric circuit by bonding to a wiring conductor of the circuit board via a conductive bonding material such as solder.
[0003]
By the way, such a ceramic wiring board is extremely small and thin with a size of about 0.5 to 10 mm square and a thickness of about 0.1 to 0.25 mm, for example, in accordance with the recent demand for miniaturization of electronic devices. It has become. In order to facilitate the handling of such a small and thin ceramic wiring board and to efficiently manufacture the ceramic wiring board and the electronic device, a large number of ceramic wiring boards are combined into one piece. It is manufactured in the form of a so-called multi-cavity wiring board that is obtained simultaneously from a large-area ceramic mother board.
[0004]
Such multi-cavity wiring boards each have a mounting portion for mounting electronic components on the upper surface at the center of the substantially square flat ceramic mother board, and a plurality of wiring conductors are arranged from the upper surface to the lower surface. A plurality of wiring board regions having the same shape to be the formed ceramic wiring board are aligned and arranged in a vertical and horizontal manner in the same direction, and the plurality of wiring board regions are surrounded on the outer periphery of the ceramic mother board. A rectangular frame-shaped discard margin area is formed. The disposal allowance area is an area for facilitating the handling of the multi-acquisition wiring board when manufacturing or transporting the multi-acquisition wiring board. The wiring board is positioned or fixed.
[0005]
Then, an electronic component is mounted on the mounting portion of each wiring board region, and the electrodes of the electronic component are electrically connected to the wiring conductor on the upper surface of each wiring board region, and then each electronic component is sealed on the ceramic mother board. The sealing resin is fixed so as to stop, and finally, the ceramic mother board is divided into each wiring board region, so that a large number of electronic devices are manufactured simultaneously and collectively.
[0006]
For such a multi-piece wiring board, a ceramic green sheet for a ceramic mother board is prepared, and a metal paste serving as a wiring conductor is printed and applied from the upper surface to the lower surface of the ceramic green sheet. It is manufactured by simultaneously firing a green sheet and a metal paste at a high temperature.
[0007]
Further, in order to divide the ceramic mother board into each wiring board region, a method of bending the ceramic mother board along the dividing line by providing dividing grooves for dividing each wiring board region on the upper and lower surfaces of the ceramic mother board. Alternatively, a method of cutting and dividing the ceramic mother board into each wiring board region using a diamond cutter or a laser cutter is employed.
[0008]
[Problems to be solved by the invention]
However, according to this conventional multi-cavity wiring board, the wiring conductor is arranged from the upper surface to the lower surface in the wiring board area arranged in the central part of the ceramic mother board, whereas the disposal margin area Is not provided with the same wiring conductor as the wiring board area, so when manufacturing this multi-piece wiring board, the central part where the wiring board area is arranged and the outer peripheral part where the disposal margin area is formed As a result, large warpage and deformation occurred in the wiring board area adjacent to the abandonment area among the many wiring board areas arranged on the ceramic mother board. It is easy to end. If a large warp or deformation occurs in the wiring board area, the electronic parts cannot be normally mounted when the electronic parts are mounted on the wiring board area, or the ceramic mother board is divided into each wiring board area. When doing so, there was a problem that it could not be divided correctly.
[0009]
The present invention has been devised in view of such conventional problems, and an object thereof is to prevent warping and deformation from occurring in each wiring board region, to enable normal mounting of electronic components and ceramics. An object of the present invention is to provide a multi-piece wiring board capable of accurately dividing a mother board into each wiring board region.
[0010]
[Means for Solving the Problems]
The multi-cavity wiring board of the present invention has a mounting portion for mounting electronic components on the upper surface at the center portion of the ceramic mother substrate, and from the upper surface to the lower surface, with respect to the center point of the upper surface when viewed from above. A plurality of wiring board regions having the same shape formed by arranging a plurality of asymmetrical wiring conductors are aligned and arranged in a vertical and horizontal manner in the same direction, and the outer periphery of the ceramic mother board is viewed from above. The dummy wiring board regions having dummy wiring conductors having the same shape as the wiring conductors and rotated 180 degrees in the horizontal direction are arranged adjacent to both ends of each row of the wiring board regions. To do.
[0011]
The multi-cavity wiring board of the present invention has a dummy wiring board region having a dummy wiring conductor having the same shape as the wiring conductor of the wiring substrate region in a top view and rotated by 180 degrees in the horizontal direction on the outer periphery of the ceramic mother board. Since the wiring board regions are arranged adjacent to both ends of each row, the firing shrinkage rate is substantially the same between the wiring board regions at both ends of each row and the dummy wiring board region adjacent thereto. Therefore, no warpage or deformation occurs in the wiring board region adjacent to the dummy wiring board region. Further, since the dummy wiring board area is provided in the opposite direction to the wiring board area, it can be easily distinguished by visual observation or an image recognition device.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an example of an embodiment of a multi-cavity wiring board according to the present invention, and FIG. 2 is a top view of the multi-cavity wiring board shown in FIG. In these figures, 1 is a ceramic mother board, 2 is a wiring board area, 3 is a dummy wiring board area, and 4 is a wiring conductor. For better understanding, the boundaries of the wiring substrate regions 2 are indicated by solid lines, and the boundaries of the dummy wiring substrate regions 3 are indicated by broken lines.
[0013]
The ceramic mother substrate 1 is made of a ceramic 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 single-layer, substantially rectangular flat plate with a side length of 20 to 200 mm and a thickness of 0.1 to 0.25 mm, and functions as a base material for simultaneously producing a large number of small ceramic wiring boards. . In the central portion of the ceramic mother board 1, there are a number of wiring board regions 2 having substantially the same rectangular shape with one side having a length of about 0.5 to 10 mm each serving as a small ceramic wiring board. And a rectangular frame-shaped discard margin area 5 surrounding a large number of wiring board areas 2 on the outer periphery thereof.
[0014]
In addition, if the length of one side of the ceramic mother substrate 1 is less than 20 mm, it is difficult to efficiently produce a large number of ceramic substrates. On the other hand, if the length exceeds 200 mm, a large warp exceeding 200 μm is likely to occur. Become. Therefore, the length of each side of the ceramic mother substrate 1 is preferably in the range of 20 to 200 mm. In addition, when the thickness of the ceramic mother board 1 is less than 0.1 mm, the ceramic mother board 1 is liable to be cracked or cracked by an external force or the like. On the other hand, when the thickness exceeds 0.25 mm, an electronic component device is obtained. It becomes difficult to reduce the thickness. Therefore, the thickness of the ceramic mother substrate 1 is preferably in the range of 0.1 to 0.25 mm.
[0015]
Such a ceramic mother substrate 1 is prepared by preparing a single ceramic green sheet having a side length of 20 to 250 mm and a thickness of about 0.15 to 0.35 mm, and performing an appropriate punching process at a high temperature. Manufactured by firing. The ceramic green sheet for the ceramic mother substrate 1 is suitable for ceramic raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide if the ceramic mother substrate 1 is made of, for example, an aluminum oxide sintered body. A ceramic slurry obtained by adding and mixing an organic binder and a solvent, a plasticizer, a dispersing agent, and the like is manufactured by forming a sheet shape by using a conventionally known doctor blade method.
[0016]
In addition, each wiring board region 2 arranged and formed in the central portion of the ceramic mother board 1 is divided into each wiring board region 2 so that each becomes a small ceramic wiring board on which the electronic component 6 is mounted. And an electronic component 6 such as a semiconductor element is mounted on the mounting portion via a solder bump 7. In addition, a plurality of wiring conductors 4 made of a sintered metal powder of tungsten, molybdenum, copper, silver, or the like led out through the through conductor from the upper surface to the lower surface are disposed. The electrodes of the electronic component 6 are electrically connected to the upper surface portion of the region 2 through the solder bumps 7. Then, after mounting the electronic component 6 on the mounting portion of each wiring board region 2 so that the electrode and the wiring conductor 4 are connected via the solder bumps 7, the electronic component 6 is mounted on the upper surface of each wiring board region 2. Then, the sealing resin 8 is fixed so as to seal 6, and then divided into the respective wiring board regions 2 to form a large number of electronic devices. In this example, the electrode of the electronic component 6 and the wiring conductor 4 are connected via the solder bump 7, but the electrode of the electronic component 6 and the wiring conductor 4 are connected by other connecting means such as a bonding wire. Also good.
[0017]
Furthermore, the wiring conductor 4 has an asymmetric shape with respect to the center point of the upper surface of each wiring board region 2 in a top view, whereby the directionality of each wiring board region 2 can be confirmed visually or by an image recognition device. It is like that. For example, in the case of a tungsten powder sintered body, a ceramic paste for the ceramic mother substrate 1 is obtained by adding a metal paste obtained by adding and mixing an appropriate organic binder, solvent, plasticizer, dispersant, etc. to the tungsten powder. Is applied to a predetermined pattern having a thickness of about 12 to 25 μm using a well-known screen printing method, and this is baked together with a ceramic green sheet for the ceramic mother board 1 to thereby form the upper surface of each wiring board region 2. Usually, a nickel plating layer having a thickness of about 1 to 10 μm and a gold plating layer having a thickness of about 0.1 to 3 μm are sequentially deposited on the exposed surface.
[0018]
Further, the disposal margin area 5 provided so as to surround a large number of wiring board areas 2 on the outer peripheral portion of the ceramic mother board 1 is handled when the multi-cavity wiring board of the present invention is manufactured or transported. This is an area for making it easy, and the ceramic green sheet for the ceramic mother board 1 and the multi-piece wiring board of the present invention are positioned and fixed by using this margin area.
[0019]
Furthermore, in the multi-piece wiring board of the present invention, a plurality of dummy wiring board regions 3 are arranged in the discard margin area 5 adjacent to both ends of each row of the wiring board areas 2. The dummy wiring board region 3 is used to approximate the firing shrinkage rate of the wiring board region 2 and the firing shrinkage rate of the disposal margin region 5 when the multi-piece wiring board of the present invention is manufactured. The dummy wiring board region 3 has the same shape as the wiring board region 2 and has a dummy wiring conductor 9 having the same shape as the wiring conductor 4 in a top view, and is similar to the wiring conductor 4 on the dummy wiring conductor 9. The nickel plating layer and the gold plating layer are applied. The dummy wiring conductors 9 are arranged so that the direction of the dummy wiring conductors 9 is 180 degrees horizontally with respect to the wiring conductors 4 in the wiring board region 2. Thus, since the dummy wiring board region 3 has the same shape as the wiring board region 2, when the multi-piece wiring board of the present invention is manufactured, the firing shrinkage rate of the wiring board region 2 and the dummy wiring board region are determined. The firing shrinkage ratio of 3 is substantially the same. Therefore, it is possible to effectively prevent the wiring board region 2 from being warped or deformed due to the difference in the firing shrinkage rate between the wiring board region 2 and the dummy wiring board region 3. As a result, the electronic component 6 can always be normally mounted on each wiring board region 2 and the ceramic mother board 1 can be accurately divided into the wiring board regions 2. Further, the dummy wiring board region 3 has the dummy wiring conductor 9 disposed in the horizontal direction 180 degrees opposite to the wiring conductor 4 of the wiring board region 2. The region 3 can be easily distinguished by visual observation or an image recognition device. Therefore, it is possible to effectively prevent the electronic component 6 from being erroneously mounted on the dummy wiring board region 3. Furthermore, since the dummy wiring board region 3 has the same shape as the wiring board region 2 and has the dummy wiring conductor 9 having the same shape as the wiring conductor 4, the dummy wiring board region 3 is soldered to the dummy wiring conductor 9. It is also possible to preliminarily specify connection conditions to the wiring conductor 4 such as the solder bumps 7 and bonding wires by performing trial mounting of the bumps 7 and trial bonding of the bonding wires. The dummy wiring conductor 9 in the dummy wiring board region 3 is made of the same material as that of the wiring conductor 4 in the wiring board region 2, and when the metal paste for the wiring conductor 4 is printed on the ceramic green sheet for the ceramic mother board 1. At the same time, the same metal paste is printed and applied to the pattern for the wiring conductor 4 in a pattern that is 180 degrees opposite in the horizontal direction when viewed from above.
[0020]
Thus, according to the multi-cavity wiring board of the present invention, the electronic component 6 is mounted on the mounting portion of each wiring board region 2 of the ceramic mother board 1, and each electrode of the electronic component 6 is connected to the upper surface of the wiring board region 2. The wiring conductor 4 is electrically connected to the wiring conductor 4 via an electrical connection means such as a solder bump, and then the upper surface of the ceramic mother board 1 and each electronic component 6 is sealed with a thermosetting resin such as an epoxy resin. The electronic component 6 is fixed by sealing resin 8 so as to be sealed, and then the ceramic mother board 1 is divided into each wiring board region 2 by using, for example, a diamond cutter or a laser cutter, so that an electronic product as a final product is obtained. A large number of devices are manufactured simultaneously.
[0021]
Note that the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the dummy wiring conductors 9 disposed on the upper and lower surfaces of the dummy wiring board region 3 are connected to each other by the through conductors that penetrate the ceramic mother board 1. The dummy wiring conductors 9 disposed on the upper and lower surfaces of the upper and lower surfaces are not necessarily connected by a through conductor, and may be independent from each other as shown in a cross-sectional view in FIG. In this case, for example, when the dummy wiring board region 3 is used for trial solder bumping or punching for bonding wires, the dummy wiring board region 3 subjected to such trial mounting or trial punching becomes the ceramic mother board. Since the dummy wiring conductors 9 on the upper surface and the lower surface of the dummy wiring substrate region 3 are not electrically connected to each other even if they are mistakenly inserted into a large number of divided wiring substrate regions 2 after dividing 1 The dummy wiring board region 3 can be identified by performing an electrical check.
[0022]
【The invention's effect】
According to the multi-cavity wiring board of the present invention, each of the ceramic mother boards has a mounting portion for mounting electronic components on the upper surface, and the center point of the upper surface from the upper surface to the lower surface as viewed from above. A plurality of wiring board regions of the same shape formed by arranging a plurality of wiring conductors asymmetric with respect to each other, are arranged in a single row vertically and horizontally with their directions aligned, and on the outer periphery of the ceramic mother board, A dummy wiring board region having a dummy wiring conductor having the same shape as the wiring conductor in a top view and rotated 180 degrees in the horizontal direction is formed adjacent to both ends of each row of the wiring board regions. Since the firing shrinkage rate is substantially the same between the wiring substrate regions at both ends of each row and the dummy wiring substrate region adjacent thereto, the wiring substrate regions adjacent to the dummy wiring substrate region Warpage or deformation does not occur Te. Therefore, it is possible to provide a multi-piece wiring board that can normally mount electronic components in each wiring board area and can accurately divide the ceramic mother board into each wiring board area. Further, since the dummy wiring board area is provided in the opposite direction to the wiring board area, the wiring board area and the dummy wiring board area can be easily distinguished visually or by an image recognition apparatus.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of a multi-cavity wiring board according to the present invention.
2 is a top view of the multi-cavity wiring board shown in FIG. 1. FIG.
FIG. 3 is a cross-sectional view showing another embodiment of the multi-cavity wiring board of the present invention.
[Explanation of symbols]
1: Ceramic mother board 2: Wiring board area 3: Dummy wiring board area 4: Wiring conductor 6: Electronic component 9: Dummy wiring conductor

Claims (1)

A plurality of wiring conductors each having a mounting portion for mounting electronic components on the upper surface and asymmetrical with respect to the center point of the upper surface as viewed from above are disposed in the central portion of the ceramic mother board from the upper surface to the lower surface. A plurality of wiring board regions having the same shape are arranged in an integrated manner in the vertical and horizontal directions with their directions aligned, and the same shape as the wiring conductor in the top view and horizontal in the outer periphery of the ceramic mother board. A multi-piece wiring board, wherein dummy wiring board regions having dummy wiring conductors rotated by 180 degrees in a direction are arranged adjacent to both ends of each row of the wiring board regions.

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