JPH11307691A - Ceramic package for electronic components - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a ceramic package with for burrs/defects for electronic components by adding glass in a conductor at a castellation of the ceramic package for electronic components, made by dividing a set of many packages through the castellations. SOLUTION: This ceramic package 11 for electronic components is made by laminating insulator layers containing. Al as the main component and has a wire-bond pad 14 at an electronic component mount 12 formed in a recess at the central part of the ceramic package 11 surface layer and a castellation 13 at the ceramic package 11 peripheral end face for relaying the wire bond pad 14 to a connection terminal 18 and for obtaining a meniscus 17 for increasing the connection strength to solder 16. The conductor of the castellation contains glass and hence it will be divided along the interface of the glass where the fracture strength in dividing the castellation 13 is not high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic package for electronic components having casting, and more particularly, to a ceramic package for a multi-piece sheet-type electronic component such as a chip carrier. The present invention relates to a ceramic package for an electronic component, in which a conductor of a castration portion contains glass in order to improve the separability of the castration portion when dividing the ceramic package.

[0002]

2. Description of the Related Art A ceramic package for an electronic component such as a chip carrier usually has a configuration in which a plurality of insulator layers on which wiring conductor layers are formed are laminated, and upper and lower insulator layers are connected by through-hole conductors. On the package surface,
As shown in FIG. 3, an electronic component mounting portion 22 for mounting an electronic component such as a semiconductor chip is formed. Then, such a ceramic package 21 for electronic components is used.
After mounting electronic components and sealing them with a lid or the like (not shown), they are mounted on a PC board (Printed Circuit Board) 25 with solder 26 or the like. At this time, in order to strengthen the adhesive force between the electronic component ceramic package 21 and the PC board 25, a cast ration 23 is provided on the end surface of the electronic component ceramic package 21 to form a meniscus 27. The cast ration 23 also serves as a wiring conductor for connecting an electronic component (not shown) to a wire bond pad 24 with a bonding wire or the like, and connecting to the connection terminal 28 via the cast ration 23.

The above-mentioned ceramic package for electronic parts is formed by laminating a plurality of conductor pastes made of a high melting point metal on an insulator layer made of a ceramic green sheet in a state of being assembled into a large number of individual pieces, and before firing, individually. Through the center of the through hole forming the castration portion, to form a chocolate break groove so that the shape of the ceramic package for electronic components of,
Bake. After that, Ni, Au plating etc. are applied and divided,
Ceramic packages for individual electronic components. Therefore, in this type of electronic component ceramic package, each electronic component ceramic package is divided into prescribed shapes. In particular, no burr or chipping occurs in the castration portion. Is needed.

[0004]

However, in the conventional ceramic package for electronic parts, the conductive paste made of the high melting point metal is obtained by mixing a resin and a solvent with only tungsten powder in order to reduce the conductive resistance of the wiring. Is generally used, so there are the following problems. Since the conductor paste is only tungsten powder,
It becomes a very dense conductor layer, and the breaking strength between metal surfaces increases. Since the conductor of the caster portion is made of the same conductive paste as the wiring conductor portion, the breaking strength at the time of division at the castration portion is also increased. For this reason, the metal surface of the casting part cannot be cut straight, and burrs and chips occur. (See Fig. 3)

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a ceramic package for an electronic component, which is obtained by dividing a multi-piece assembly through a casting section. An object of the present invention is to provide a ceramic package for electronic components with less burrs and chips by including a glass in a conductor of a casting part.

[0006]

A ceramic package for an electronic component according to the present invention as a means for solving the above-mentioned problem is a ceramic package for an electronic component obtained by dividing a multi-piece assembly through a casting section. The conductor of the casting portion includes glass. Further, in the ceramic package for an electronic component according to the present invention, in the above invention, the conductor of the casting portion includes a metal powder containing 30% by weight or less of glass.

[0007] Here, the multi-unit assembly is formed by arranging a large number of ceramic packages for electronic components on a ceramic sheet in order to produce ceramic packages for individual electronic components. Each ceramic package for electronic components is composed of a number of ceramic packages for electronic components that are to be printed on a plurality of ceramic green sheets. Then, after plating, it is obtained by dividing along a chocolate break groove provided in advance. The castration is necessary to strengthen the adhesive strength with the PC board when the ceramic package for electronic components is surface-mounted on the PC board. Since a through-hole is formed at a position to be an end face of the ceramic package for each electronic component, a hollow through-hole is printed with a conductive paste, and division is performed through the through-hole when dividing along the chocolate break groove. The conductor-printed inner wall of the through-hole is exposed at the end face of the ceramic package for electronic components to form the castration portion. By such a forming method, a large number of ceramic packages for electronic components with castration can be easily manufactured at once. By the way, as the conductor printing of the through hole for the casting, the conductor paste used is the same as the printed circuit conductor printing, in which a resin and a solvent are mixed with a metal such as tungsten or molybdenum.
This uses as pure a metal as possible because the conduction resistance of the wiring circuit conductor must be as low as possible. Therefore, the same conductor is used in the conductor printing of the through hole. However, since the conductor thickness of the through-hole portion tends to be considerably thicker than the conductor thickness of the wiring circuit conductor portion, even if glass is mixed into the conductor of the through-hole portion, the conduction resistance does not increase. Further, conventionally, since the masks for screen printing of the wiring circuit conductor printing and the conductor printing of the through-hole portion are different from each other and the processes are separated, the number of processes increases even if the type of the conductor paste is changed. It does not become.

[0008]

As is apparent from the above description, according to the ceramic package for electronic parts of the present invention, the conductor of the cast part of the ceramic package for electronic parts obtained by dividing a large number of assemblies through the casting part. Since it contains glass, it is divided along the glass interface where the fracture strength at the time of division of the castration part is not high, so it is possible to cut the conductor metal surface of the castration part straight, and to suppress the occurrence of burrs and chipping It has the effect that can be done. In addition, the conductor of the castration portion has an effect that it is possible to suppress an increase in conduction resistance by containing 30% by weight or less of glass in the metal powder.

[0009]

Preferred embodiments of the present invention will be described below with reference to the drawings.
1 and 2 show a ceramic package for an electronic component according to the present embodiment, FIG. 1A is a schematic perspective view of the ceramic package for an electronic component according to the embodiment, and FIG. FIG. 2 is a schematic cross-sectional view of a connecting portion of the ceramic package for an electronic component to a PC board, and FIG. 2 is a schematic perspective view of the ceramic package for an electronic component in a multi-unit assembly.

Embodiment A ceramic package for an electronic component according to this embodiment is an LC
A C (Leadless Chip Carrier) type multilayer ceramic package 11 for electronic components, in which a plurality of insulator layers mainly composed of alumina are laminated and formed in a concave shape at the center of the surface of the ceramic package for electronic components. And a wire bond pad 14 for connecting the electronic component and a bonding wire (not shown) to the mounted electronic component mounting portion 12 called a cavity, and the wire bond pad 14 and the electronic component At the same time as relaying the connection terminals 18 provided on the back surface of the ceramic package,
And a casting 13 for obtaining a meniscus 17 for strengthening the connection strength with the caster. Although not shown, the electronic component ceramic package 11 is mounted on an electronic component mounting portion 12 with an electronic component such as a semiconductor chip, sealed with a sealing lid, and mounted on a PC board.

This ceramic package for electronic parts 11
Is to drill through holes for casting 13 in a green sheet of alumina to be an insulator layer, screen-print the through holes with tungsten paste or the like mixed with glass powder, After screen printing metal wiring patterns and via holes for wiring, a plurality of the green sheets are laminated, fired simultaneously at 1500 to 1600 ° C. in a reducing atmosphere of hydrogen and nitrogen, and plated with Ni or Au. By dividing the individual assembly electronic component ceramic package 19 through the central part of the through hole for casting 13, the individualized ceramic package 11 for electronic component with casting is obtained.

Here, as the alumina, dioctyl adipin is added to a powder obtained by adding a small amount of a sintering aid such as magnesia, silica and calcium carbonate and a coloring agent such as titanium oxide, chromium oxide and molybdenum oxide to alumina powder. Plasticizers such as acids, acrylic resins, binders such as butyral resins and toluene, xylene, add solvents such as alcohols,
The slurry is sufficiently kneaded to prepare a slurry having a viscosity of 2000 to 40000 cps, and used as a green sheet having a thickness of, for example, 0.3 mm by an ordinary doctor blade method. The conductor paste for through-hole printing of the casting 13 was prepared by adding ₂ to 30% by weight of TiO2 as a glass component to 70 to 98% by weight of tungsten powder and adding a resin and a solvent. Here, if the glass content is 2% by weight or less, the effect of preventing generation of burrs and chips at the time of division is reduced, and if the glass content exceeds 30% by weight, the conduction resistance increases.

Incidentally, the ceramic package 11 for an electronic component of the present embodiment has three green sheets. There is no cast-through hole in the green sheet that is the uppermost insulator layer, and there is a cast-through hole in the green sheets that are the second and third insulator layers. ing. Next, in order to confirm the operation and effect of the electronic component ceramic package 11 of the present embodiment, the ceramic package 19 for multiple component electronic components is divided through the center of a through-hole hole for casting 13, and divided.
The result of measuring the size of the burr of the cast portion of the 30 electronic component ceramic packages with the individual casted electronic component ceramic package 11 was compared with a conventional through-hole printing conductor for casting. The results are shown in Table 1 together with Comparative Examples in which the paste did not contain glass. Note that the burrs and the chips have a split piece left on one side at the time of splitting, and a split piece is taken on the other side.

[0014]

[Table 1]

As a result, the ceramic package 11 for an electronic component according to the present embodiment has the burrs 2 shown in the conventional ceramic package 21 as schematically shown in FIG.
9 and chipping 30 were greatly improved. Also, it was confirmed that there was no increase in conduction resistance due to mixing of glass. From this, it was confirmed that mixing glass with the conductor paste for through-hole printing for casting reduces generation of defects such as burrs and chips when dividing a large number of pieces into individual pieces.

The present invention is not limited to the above-described embodiment, but can be modified and implemented without departing from the gist of the present invention. By the way, as a form of the electronic component ceramic package, it has been described that the wire bond pad is present in the electronic component mounting portion, but in a case where the crystal resonator is mounted in place of the semiconductor chip, the conductor wiring portion is used. The present invention can also be applied to a case where a wire bond pad to which an electronic component is directly connected does not exist. Although the number of ceramic green sheets is three, the number of ceramic green sheets is not limited. Furthermore, although the description has been made of TiO ₂ as the glass, the material is not limited to SiO _{2 and the} like, and can be applied. Further, the metal conductor is described as being made of tungsten, but the material such as molybdenum is not limited, and other metals can be applied. further,
Although the ceramic has been described as alumina, there is no limitation on the material such as aluminum nitride and glass ceramic.

[Brief description of the drawings]

FIG. 1A is a schematic perspective view of a ceramic package for electronic components according to an embodiment of the present invention. (B)
FIG. 1 is a schematic partial enlarged cross-sectional view for describing a ceramic package for an electronic component according to an embodiment of the present invention at the time of mounting.

FIG. 2 is a perspective view showing a state of a multi-unit assembly of the ceramic package for an electronic component according to the embodiment of the present invention.

FIG. 3A is a side view including a schematic partial cross-sectional view of a conventional ceramic package for electronic components. (B)
FIG. 3 is a schematic partial enlarged cross-sectional view for explaining a conventional ceramic package for electronic components at the time of mounting.

[Explanation of symbols]

11 ... Ceramic package for electronic parts, 12 ...
・ Electronic component mounting part, 13 ・ ・ ・ Castation, 1
4 ... wire bond pad, 15 ... PC board,
16: solder, 17: meniscus, 18: connection terminal, 21: ceramic package for electronic components,
22: electronic component mounting part, 23: castration, 24: wire bond pad, 25: PC
Board, 26: solder, 27: meniscus, 28
... Connection terminal, 29 ... Burr, 30 ... Chip

Claims (2)

[Claims] 1. A ceramic package for an electronic component, which is obtained by dividing a multi-piece assembly through a casting portion, wherein a conductor of the casting portion includes glass. 2. The ceramic package for an electronic component according to claim 1, wherein the conductor of the casting portion includes a metal powder containing 30% by weight or less of glass.