JP2593524Y2 - Hybrid IC - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement for improving the temperature cycling capability of a hybrid IC.

[0002]

2. Description of the Related Art FIG. 3 shows a structure of a conventional hybrid IC, particularly a component mounting portion. In FIG. 1, reference numeral 1 denotes an insulating substrate made of a material such as alumina. The conductive wiring body 2 is formed on the upper surface of the insulating substrate 1. After the conductive wiring body 2 is formed, a glass protective film 3 is formed on the surfaces of the insulating substrate 1 and the conductive wiring body 2 in order to prevent moisture or the like from entering. When the glass protective film 3 is formed, a component connection surface 2A for connecting the component 4 is formed on the conductive wiring body 2 so as to be exposed. The lead 4A of the electric component 4 is connected to the component connection surface 2A by the solder 5, and the electric component 4 is mounted.

[0003]

The electric component 4 generates a force that spreads outward between the leads 4A due to self-heating during energization, and an inward force between the leads 4A when power supply is cut off. Occurs. Therefore, the conductive wiring 2 receives stress from the electric component 4 as the power supply is repeatedly turned on and off. In particular, as shown in an enlarged manner in FIG. 4, stress concentration occurs at a boundary portion between the glass protective film 3 and the solder 5, a crack 6 is generated in this portion, and an accident leading to conductor breakage after the crack 6 occurs may occur. Many.

The mechanism of crack generation is considered as follows. In other words, glass has a high hardness as generally known. For this reason, when a stress is applied from the lead 4A of the electric component 4, the glass protective film 3 does not hardly deform, so that the stress concentrates on the edge of the portion covered with the glass. It is considered that a crack 6 is formed immediately below the.

[0005] In addition, the components of the solder 5 diffuse into the portion of the conductive wiring body 2 covered with the solder 5. In addition, the conductive wiring body 2
Is also diffused into the solder 5 to form an alloy with each other. Solder 5
Is diffused into the conductive wiring body 2 formed of, for example, AgPd or AgPt, the conductive wiring body 2
A phenomenon is seen in which the volume expands and the quality of the material changes to fragile performance, and it is considered that the crack 6 is also likely to occur due to this phenomenon.

An object of the present invention is to suppress the occurrence of cracks 6 and provide a highly durable hybrid IC.

[0007]

According to the present invention, a buffer band is provided between a portion of the conductive wiring body covered with the glass protective film 3 and a part of the conductive wiring body covered with the solder. The structure is such that stress can be prevented from being concentrated and applied to the boundary between the portion to be covered and the portion to be covered by the glass protective film.

According to the present invention, a buffer band is provided at the boundary between the component connecting surface of the conductive wiring body and the glass protective film. Therefore, even when a stress due to expansion and contraction of the component is applied, the buffer band is provided. The stress is dispersed and applied to the conductive wiring body. Therefore, no crack occurs in the conductive wiring body. Therefore, there is no possibility that a breakage accident occurs, and a highly reliable hybrid IC can be provided.

[0009]

FIG. 1 shows an embodiment of the present invention. In the present invention, in a hybrid IC in which a glass protective film 3 is applied on the conductive wiring body 2 while leaving the component connection portion 2A, a portion of the conductive wiring body 2 covered with the solder 5 and a portion covered with the glass protective film 3 are provided. It is characterized by a structure in which a buffer band 7 is provided between a portion to be covered.

The method of forming the buffer zone 7 is to form, for example, an epoxy-based heat-resistant resin layer 8 on the glass protective film 3 by printing. At the time of this printing, a part of the resin layer 8 is replaced with the component connection surface 2A.
And a resin layer 8 is adhered on the conductive wiring body 2. A buffer band 7 is formed by the resin layer 2 applied on the conductive wiring body 2. That is, after forming the resin layer 8, the leads 4A of the component 4 are soldered. When the thickness of the conductive wiring body 2 is, for example, about 12 μm,
Make the dimension L of the buffer band 7 sufficiently longer than the thickness of the conductive wiring body 2.
The thickness may be about 100 to 300 μm. That is, the extension amount of the resin layer 8 may be set to about 200 to 300 μm.

[0011]

As described above, by providing the buffer band 7 formed by directly covering the conductive layer 2 with the resin layer 8, the portion of the conductive layer 2 where the solder 5 is deposited and the resin layer 8 are formed. Stress is not concentrated between the portion and the portion to be covered. That is, the resin has a lower hardness than glass, and therefore has a property of being more easily deformed than glass by external force. As a result, when the electric component 4 thermally expands, the resin layer 8 in contact with the solder 5 also deforms to the extent that it follows the stress.
And the stress is not locally concentrated on the conductive wiring body 2. In particular, formed by the resin layer 8
Make the buffer band 7 200 to 3 sufficiently longer than the thickness of the conductive wiring body 2.
Since it is about 00 μm,
No stress is transmitted. As a result, the conductive wiring body 2
Cracks can be prevented.

Further, a phenomenon is observed in which the volume of the conductive wiring body 2 expands due to the diffusion of a part of the component, for example, tin from the solder 5 to the conductive wiring body 2 during practical use. As a result of this phenomenon, as shown in the enlarged view of FIG. 2, the contact portion of the resin layer 8 with the solder 5 is lifted, and the mechanical connection between the solder 5 and the resin layer 8 is further increased. The resin layer 8 is more easily deformed by the stress applied from the lead 4A of the fourth member 4. Therefore, the force received from the lead 4A is not concentrated on the conductive wiring body 2, so that the generation of cracks is suppressed and the hybrid I having a large temperature cycle resistance is provided.
C can be provided.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view for explaining an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view for explaining a deformation state of a resin layer and a solder portion occurring during practical use of the hybrid IC according to the present invention.

FIG. 3 is a cross-sectional view for explaining a conventional technique.

FIG. 4 is an enlarged cross-sectional view for explaining a problem of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating board 2 Conductive wiring body 3 Glass protective film 4 Electric component 4A Lead 5 Solder 6 Crack 7 Buffer band 8 Resin layer

Claims (1)

(57) [Scope of request for utility model registration] 1. A conductive wiring body is formed in a predetermined shape on an insulating substrate, a glass protective film is applied on the upper surface of the conductive wiring body while leaving a component connection surface, and the exposed conductive wiring body is soldered to the exposed conductive wiring body.
Therefore, the structure of connecting the terminals of the parts electrically and mechanically
In the brid IC, the conductive wiring is provided between the edge of the glass protective film and the solder.
200-300 μm, which is much longer than the thickness of the body
To separate the glass protective film and the solder.
Resin without exposing the conductive wiring body between the parts
A hybrid IC having a structure in which a buffer band formed by applying a layer is provided .