JPH0612623Y2 - Chippujiyanpa - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a chip jimper which is a chip-shaped electronic component for short circuit.

[Prior Art] As shown in Fig. 4 and Fig. 5 which is a sectional view taken along the line AA of the conventional chip jumper, a ceramic board 1 having a rectangular parallelepiped shape and a top surface and both end surfaces of the ceramic board 1 are provided. It is composed of a silver underlayer 2 which is held and extended in a substantially C-shape, a nickel plating layer 3 applied to the silver underlayer 2, and a solder plating layer 4 applied to the nickel plating layer 3. The silver underlayer 2 is formed by coating the ceramic substrate 1 with a metal glaze prepared by mixing a silver paste (or a silver / palladium paste) and a glass paste on the ceramic substrate 1 using a printing technique or the like, and then drying and firing the same. It has been obtained. In addition, the above nickel plating layer 3 for preventing silver cracks in the silver underlayer 2
All of the solder plating layers 4 for ensuring solder wettability are formed by a known barrel plating method in order to improve productivity.

The chip jumper is mounted at a predetermined position on the printed wiring board with the bottom surface side of the ceramic substrate 1 facing downward, and the solder plating layer 4 is soldered to the circuit pattern by the dip soldering method.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional chip jig jumper, when the solder plating layer 4 is formed by the barrel plating method, the top surfaces of the relatively soft solder plating layers 4 are struck to each other. In some cases, defective products such as those shown in (3) may occur, and this defective plating is a factor that reduces the yield.

Also, in order to keep the impedance of the chip jumper after mounting low, the solder plating layer 4 should be used during the dip soldering.
It is desirable that the molten solder that adheres to the whole of the conduction path be continuous, that is, the molten solder should adhere so as to hold the solder plating layer 4. On the top surface of the, the molten solder is likely to flow down in the lateral direction, so that there is a possibility that the molten solder may not be continuous and the impedance may become high.

Therefore, it is an object of the present invention to provide a chip jumper which can prevent the occurrence of defects during the solder plating process and has good impedance characteristics.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a ceramic substrate, a silver underlayer extending by holding the top surface and both end surfaces of the ceramic substrate, and the silver underlayer. In a chip jumper that is equipped with a solder plating layer that covers, and is mounted by a deep soldering method, on the top surface side of the ceramic substrate, extends along the silver underlayer, and projects from the top surface of the solder plating layer. This is achieved by providing an insulating ridge having a sufficient thickness.

[Operation] According to the above means, the insulating ridge is formed in advance,
Then, when solder plating is performed by the barrel plating method, the protrusions serve as spacers during the plating process and the top surfaces of the solder plating layers cannot adhere to each other, so that defective plating can be avoided. Since the function of guiding the flow of molten solder at that time is fulfilled, the molten solder is likely to be contiguous on the top surface of the solder plating layer, thus improving the impedance characteristics.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a perspective view of the chip jumper according to this embodiment, and FIG.
The drawing is a cross-sectional view taken along the line BB in FIG. 1, and FIG. 3 is the CC taken in FIG.
In the line sectional view, the portions corresponding to those in FIGS. 4 and 5 are denoted by the same reference numerals.

The chip jumper shown in FIGS. 1 to 3 is a ceramic substrate 1.
A ridge 5 made of a glass coating material and extending in the longitudinal direction along the silver base layer 2 is attached to each of both sides of the top surface of the silver base layer 2 that holds and extends. After forming the silver underlayer 2 by coating the ceramic substrate 1 with metal glaze and drying and firing, a pair of ridges 5 are formed by screen-printing glass paste and drying and firing. The nickel plating layer 3 and the solder plating layer 4 are sequentially formed by the barrel plating method. However, the thickness of each ridge 5 is set so as to be larger than the total thickness of the nickel plating layer 3 and the solder plating layer 4, and therefore each ridge 5 is soldered as shown in FIGS. It protrudes from the top surface of the metal layer 4.

In such a chip jig jumper, the protrusions 5 serve as spacers to prevent the top surfaces from adhering to each other during the plating process performed collectively in the barrel, so that the relatively soft solder plating layer 4 is also stuck to the top surface. It is possible to surely form without causing the defective plating, and it is possible to greatly improve the yield.

The chip jumper is mounted on the printed wiring board by the deep soldering method. At the time of the deep soldering, the ridges 5 function to guide the flow of the molten solder, and the molten solder is extended on the top surface of the solder plating layer 4. Since it is guided in the direction, the molten solder that adheres to the solder plating layer 4 naturally continues for the entire conduction path, and the impedance can be suppressed low.

Although the ridges made of the glass coating material are provided in the above embodiment, the ridges may be made of other insulating material. Further, it is preferable that the ridges are provided on both side portions on the top surface side of the ceramic substrate as in the above embodiment, but the formation position, shape, number and the like are not limited to those in the above embodiment.

[Advantages of the Invention] As described above, according to the present invention, since the insulating ridges are provided on the top surface side of the ceramic substrate, the top surfaces of the solder plating layers are stuck to each other during the solder plating process. Yield is improved by eliminating defective plating.
In addition, since the molten solder during the deep soldering is guided by these ridges and tends to be continuous in the entire conduction path, the impedance can be suppressed to a low level, and as a result, it is possible to provide a high-quality chip zipper at a low cost. it can.

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention. FIG. 1 is a perspective view of a chip jumper, FIG. 2 is a sectional view taken along line BB of FIG. 1, and FIG. 3 is C of FIG. -C line cross-sectional view, FIG. 4 is a perspective view of a chip jumper according to a conventional example, FIG. 5 is a cross-sectional view taken along the line A-A of FIG. 4, and FIG. 6 is an explanatory view showing defective plating during a soldering process. is there. 1 ... Ceramic substrate, 2 ... Silver base layer, 3 ... Nickel plating layer, 4 ... Solder plating layer, 5 ... Ribs.

Claims (1)

[Scope of utility model registration request] 1. A ceramic substrate, a silver underlayer extending so as to hold the top surface and both end faces of the ceramic substrate, and a solder plating layer for covering the silver underlayer. The ceramic substrate is mounted by a dip soldering method. In the Chippujiyanpa,
A chip jihamper, characterized in that an insulating ridge extending along the silver base layer and having a thickness sufficient to project from the top surface of the solder plating layer is provided on the top surface side of the ceramic substrate.