JP3537653B2 - Multi-cavity ceramic substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting an electronic component such as a semiconductor device by dividing a large-area mother board along a grid-shaped dividing groove formed on at least one main surface thereof. The present invention relates to a multi-cavity ceramic substrate in which a large number of ceramic substrates are collectively manufactured.

[0002]

2. Description of the Related Art Conventionally, a multi-cavity ceramic substrate on which a large number of ceramic substrates for mounting electronic components such as semiconductor elements are collectively manufactured is formed on the upper surface of a mother substrate made of a flat ceramic. And a grid-like dividing groove for dividing the mother substrate into a number of ceramic substrates.

[0003] Each of the ceramic substrates is provided with a wiring conductor made of metallized metal from the upper surface to the lower surface. Electronic components such as semiconductor elements are electrically connected to the wiring conductor on the upper surface of each ceramic substrate. It is mounted as follows.

[0004] The multi-cavity ceramic substrate is so-called chocolate break by applying a force to cause twisting or bending to the mother substrate along the dividing grooves after mounting electronic components such as semiconductor elements on each ceramic substrate. It is divided into a large number of ceramic substrates, and electronic components such as semiconductor elements are mounted on each ceramic substrate before the division, whereby a large number of electronic devices having the electronic components mounted on the ceramic substrate are collectively manufactured. Will be.

[0005] In such a multi-cavity ceramic substrate, the dividing grooves formed in the mother substrate are divided when the mother substrate is divided into a number of ceramic substrates by chocolate breaking along the dividing grooves. In order to prevent burrs from being generated on the ceramic substrate, it is usually formed to a depth of about half or more of the thickness of the mother substrate.

[0006]

However, recently,
With the demand for smaller and thinner electronic devices, ceramic substrates for mounting electronic components have also become smaller and thinner, and a large number of ceramic substrates for making such smaller and thinner ceramic substrates have been required. As the individual ceramic substrate, a very thin type mother substrate having a thickness of, for example, 0.5 mm or less has been used.

However, a multi-cavity ceramic substrate is
Since the dividing grooves are formed at a depth of about half or more of the thickness of the mother substrate on which a number of ceramic substrates are formed, when the thickness of the mother substrate becomes extremely thin, the dividing grooves are formed. The mechanical strength of the mother board in the part where it is located becomes extremely weak, for example, when only a small external force that causes twisting or bending is applied to the mother board when mounting electronic components such as semiconductor elements on each ceramic board. The mother board is easily broken along the dividing groove, and as a result, it is difficult to intensively manufacture a large number of electronic devices in which electronic components are mounted on the ceramic substrate.

The present invention has been devised in order to solve the above-mentioned drawbacks, and it is an object of the present invention that a mother board has sufficient mechanical strength and is easily broken along a dividing groove by a small external force. A plurality of thin ceramic substrates can be stably formed, thereby providing a multi-cavity ceramic substrate capable of collectively manufacturing a large number of electronic devices in which electronic components are mounted on the ceramic substrate. It is in.

[0009]

According to the present invention, there is provided a multi-piece ceramic substrate, wherein a plurality of ceramic substrates divided by lattice-shaped dividing grooves are formed in a central region of a mother substrate made of ceramic. A frame-shaped thick portion thicker than the ceramic substrate is integrally provided in an outer peripheral region of the ceramic substrate, and the thick portion is formed apart from the division groove.

According to the multi-cavity ceramic substrate of the present invention, a frame-shaped thick portion thicker than the ceramic substrates is formed in the outer peripheral region of the mother substrate formed by dividing the ceramic substrate in the central region. Since they are integrally formed, the mechanical strength in the outer peripheral region of the motherboard becomes strong, and a slight amount of twisting or bending occurs when electronic components such as semiconductor elements are mounted on each ceramic substrate. Even if an external force is applied to the motherboard, the motherboard does not twist or bend due to such a small external force, and does not break along the dividing groove. As a result, a large number of electronic devices having electronic components mounted on an extremely thin ceramic substrate can be intensively and stably manufactured.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a sectional view showing an example of an embodiment of a multi-cavity ceramic substrate according to the present invention. In this figure, 1 is a mother substrate made of a flat ceramic, 2 is a ceramic substrate, 3 is a thick portion, 4 is a wiring conductor, and 5 is a dividing groove.

The mother substrate 1 is a flat substrate made of a ceramic such as an aluminum oxide sintered body, for example, and a large number of ceramic substrates 2 are defined in a central region by a dividing groove 5 formed in a lattice shape. As a result, a frame-shaped thick portion 3 thicker than the ceramic substrate 2 is integrally formed in an outer peripheral region of the mother substrate 1 corresponding to an outer peripheral portion of the ceramic substrate 2 forming region. It is provided by doing.

The mother substrate 1 is manufactured by a conventionally well-known ceramic green sheet laminating method. Specifically, for example, a sintering aid such as silicon oxide, magnesium oxide, calcium oxide or the like is added to aluminum oxide powder, and a binder, An organic solvent, a plasticizer, etc. are added and molded into a sheet by a well-known doctor blade method to obtain a plurality of ceramic green sheets. The required number of layers are laminated in a predetermined lamination order, and the ceramic green sheet laminate thus obtained is placed in a reducing atmosphere at 1500 to 1600 ° C.
It is manufactured by firing.

A large number of ceramic substrates 2 formed vertically and horizontally in the central region of the mother substrate 1 have a function as a circuit board of an electronic device on which electronic components such as semiconductor elements are mounted. A plurality of wiring conductors 4 made of metallized metal are formed on the respective ceramic substrates 2 from the upper surface to the lower surface, and each electrode of an electronic component mounted on the upper surface of the ceramic substrate 2 is formed on the upper surface of the wiring conductor 4. Are electrically connected via a bonding wire or the like, and a portion led out to the lower surface of the ceramic substrate 2 is connected to a wiring conductor of an external electric circuit board via a solder or the like.

For the wiring conductor 4, a metal paste obtained by adding a suitable organic solvent, a binder, or the like to a high melting point metal powder such as tungsten or molybdenum is mixed with a ceramic green sheet serving as the mother substrate 1. By printing and applying in a predetermined pattern by a screen printing method, it is fired together with the mother substrate 1 to be integrally formed.

The ceramic substrate 2 is formed as an extremely thin one having a thickness of less than 0.5 mm in order to meet the demand for miniaturization and thinning. Only the central region where such a ceramic substrate 2 is formed is formed. In the case where the mother board 1 is formed, when the electronic components such as the semiconductor elements are mounted on the respective ceramic boards 2, a slight external force which causes twisting or bending is applied along the dividing groove 5 easily. Will be broken.

On the upper surface of the mother substrate 1, division grooves 5 for dividing a large number of ceramic substrates 2 are formed in a lattice shape.
After the semiconductor element is mounted on the ceramic substrate 2, the dividing groove 5 applies a predetermined magnitude of external force that causes the mother substrate 1 to twist or bend, and causes the mother substrate 1 to perform a chocolate break along the dividing groove 5. The ceramic substrate 2
When a large number of substrates are collectively manufactured, the mother substrate 1 is easily and accurately divided into the ceramic substrates 2. Such a dividing groove 5 is formed by, for example, pressing a cutter blade or the like having an acute cutting edge angle to a predetermined depth into a ceramic green sheet serving as the mother substrate 1, and the depth is usually the thickness of the ceramic substrate 2. Is formed so as to be about half or more.

The thick portion 3 formed in the outer peripheral region of the mother substrate 1 corresponding to the outer peripheral portion of the formation region of the ceramic substrate 2 twists the mother substrate 1 when electronic components such as semiconductor elements are mounted on each ceramic substrate 2. It acts to protect it from a slight external force that causes bending or bending, and is integrally formed in a frame shape so as to surround the central region where the ceramic substrate 2 is formed on one of the outer peripheral regions on the front and back surfaces of the mother substrate 1. It is provided by that.

In this case, the mother substrate 1 is formed integrally with a thick portion 3 thicker than the ceramic substrate 2 on the outer peripheral portion of the central region where a large number of ceramic substrates 2 are formed. Even if a small external force is applied to the mother substrate 1 such that the mechanical strength becomes strong and an electronic component such as a semiconductor element is twisted or bent when the electronic component such as a semiconductor element is mounted on each ceramic substrate 2, Such a small external force does not cause twisting or bending and break along the dividing groove 5.

The thickness and width of the thick portion 3 are determined by applying a slight external force to the mother substrate 1 to cause twisting or bending when mounting electronic components such as semiconductor elements on each ceramic substrate 2. However, the thickness and width may be set so that the mother substrate 1 is not twisted or bent by such a small external force. The thickness of such a thick portion 3 differs depending on characteristics such as mechanical strength and toughness based on the material and the like of the mother substrate 1. For example, in the case of an aluminum oxide sintered body, if the thickness is not more than 0.5 mm, There is a tendency that the mechanical strength of the substrate 1 cannot be increased. For the aluminum nitride sintered body, it is 0.7 mm or more, for the mullite sintered body, it is 0.8 mm or more, and for the glass ceramic sintered body, it is 0.1 mm or more.
Unless it is 8 mm or more, there is a tendency that the mechanical strength of the mother substrate 1 cannot be increased. On the other hand, if the thickness of the thick portion 3 exceeds 5.0 mm for each material, the mother substrate 1 becomes thicker and bulky, which makes it difficult to use, and it is difficult to make a stable chocolate break. It is preferable that the thickness be in the range of about 0.5 to 5.0 mm.

The width of the thick portion 3 is less than 2% of the width of a central region formed by arranging a large number of ceramic substrates 2 vertically and horizontally. On the other hand, if the width exceeds 50% of the width of the central region, the area of the thick portion 3 occupying the mother substrate 1 increases, and a large number of ceramic substrates 2 are formed. The thick part 3
Is preferably in the range of about 2 to 50% of the width of the central region.

When the thick portion 3 is formed without being separated from the dividing groove 5 surrounding the central region where a large number of ceramic substrates 2 are formed vertically and horizontally, the thick portion 3 is divided with the inner surface of the thick portion 3. The grooves 5 are opposed to each other. When the chocolate breaks along the division grooves 5 formed on the mother substrate 1 to divide the ceramic substrates 2 into a plurality of ceramic substrates 2, burrs and chips are generated on the divided ceramic substrates 2. However, the thick portion 3 is separated from the dividing groove 5 and the thick portion 3 is located outside the central region.
Is formed, the inner surface of the thick portion 3 does not face the dividing groove 5, and when the chocolate breaks along the dividing groove 5 formed on the mother substrate 1 and the ceramic substrate 2 is divided into a plurality of ceramic substrates 2. It is preferable that the thick portion 3 is formed apart from the dividing groove 5 because burrs and chips are not easily generated in the divided ceramic substrate 2.

The thick portion 3 has a dividing groove 5 extending on the upper surface thereof, and has a thicker portion at a position facing the dividing groove 5 extending on the lower surface thereof. If the auxiliary division groove 6 is formed so as to be half or more of the thickness of the portion 3, when the mother substrate 1 is divided along the division groove 5 after mounting electronic components such as semiconductor elements on each ceramic substrate 2, Since the mother substrate 1 can be easily and accurately divided along the dividing groove 5, the dividing groove 5 is extended on the upper surface of the thick portion 3 and the dividing groove is extended on the lower surface. It is preferable that an auxiliary division groove 6 having a depth equal to or more than half the thickness of the thick portion 3 is formed at a position facing the division groove 5 together with the division groove 5.

Thus, according to the multi-cavity ceramic substrate of the present invention, after an electronic component such as a semiconductor element is mounted on each ceramic substrate 2, an external force which causes the mother substrate 1 to twist or bend along the dividing groove 5 is applied. By performing the chocolate break, a large number of electronic devices, which are divided into a large number of ceramic substrates 2 and electronic components such as semiconductor elements are mounted on the ceramic substrates 2, are to be manufactured collectively.

Although the present invention has been described in detail with reference to the embodiments, the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the scope of the invention. Can be changed.

[0026]

According to the multi-cavity ceramic substrate of the present invention, a frame-shaped thick portion thicker than the ceramic substrates is provided in the outer peripheral region of the mother substrate in which a large number of ceramic substrates are partitioned in the central region. Therefore, the mechanical strength in the outer peripheral region of the mother board becomes strong, and a slight external force that causes twisting or bending when mounting electronic components such as semiconductor elements on each ceramic board is applied to the mother board. Even when the voltage is applied, the mother substrate does not twist or bend due to such a small external force, and does not break along the division grooves. As a result, a large number of electronic devices having electronic components mounted on an extremely thin ceramic substrate can be intensively and stably manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an embodiment of a multi-cavity ceramic substrate of the present invention.

Claims (1)

(57) [Claims] 1. A ceramic substrate having a plurality of ceramic substrates divided by lattice-shaped dividing grooves in a central region of a ceramic mother substrate, and a frame-shaped thick wall thicker than the ceramic substrate in an outer peripheral region of the mother substrate. Contact integrally provided on a part
The thick portion is formed separately from the dividing groove.
Multi-piece ceramic substrate, characterized in that that.