JP2002050846A - Surface mount package device for long lead - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package surface-mount electronic device of a long lead having the connection pad of a large area for improving the soldering reliability of the surface-mounted package. SOLUTION: The package consists of an insulation board; at least one via hole passing through the board for inserting a lead wire; material which is used for plating along the wall of the via hole to be soldered to the lead wire and extended to a flat soldering pad along the bottom of the board to be surface-mounted to a mother board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to electronic device packages and more particularly to surface mount packages.

[0002]

2. Description of the Related Art Many types of electronic devices, such as capacitors and resistors, have long leads. With the advent of printed circuits, it is desirable to use surface mount packages for devices to easily connect to printed circuit boards.

FIG. 1 is a front view of a prior art package for a typical long lead device. Substrate 20 has two via holes 24 through which device leads (not shown) extend. FIG. 2 is a cross section AA ′ of FIG.
FIG. The substrate 20 has two grooves 22 outside the via holes 24. When the device leads are inserted through the via holes, the leads are bent outwardly with respect to the grooves 22 and recess into the grooves 22 as shown in FIG. FIG. 4 is a side view of the package with the device 10 inserted through the package. Device 10
Are inserted through the substrate 20 and bent outward. Due to the recessed groove 22, the lower end of the bent lead 12 is used sparingly at the bottom of the substrate 20. Thus, the bottom surface of the package is flat for surface mounting to a printed circuit board.

[0004] However, the rounded ends of the leads cannot provide a large contact area for soldering to a printed circuit board, and the soldering is not reliable. Lead 1
Even if the two ends are clipped flat to increase the contact area, the increase in soldering area is limited.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a package for surface mounting of long lead electronic devices.

It is another object of the present invention to provide a large area bond pad to improve the soldering reliability of a surface mount package.

[0007]

SUMMARY OF THE INVENTION These objects are achieved by a plated through via hole in a substrate of a surface mount package. The bottom of the plated through metal is enlarged as a pad to provide a surface for large and reliable surface mounting. When the leads are heated, they are soldered to the plated through-hole walls. Alternatively, the leads of the leads are folded back before being inserted into the plated through holes.

[0008]

FIG. 5 is a front view of a package according to the present invention. The insulating substrate 30 of the package has two via holes 34. The via holes are plated with a solder material as shown in the cross-sectional view of the package shown in FIG. The bottom of the plated metal 36 is adhered to the bottom of the substrate 30,
It is enlarged to a flat pad as shown in FIG.
These enlarged bottom pads provide a reliable solder contact for surface mounting to the motherboard.

FIG. 8 is a cross-sectional view of a package having leads 12 of a long lead device 10 inserted into plated through via holes in substrate 30. FIG. On the other hand, the enlarged bottom pad 36 of the plated through via hole
Forms a tight soldering contact with the motherboard (not shown).

The solder material 36 for the via hole is a tin-lead alloy, which is melted by heating. If the long leads of the device 10 are very thin, the leads 22 of the device 10 will be folded inside the plated through via holes as shown in FIG. The folds increase the contact area between the plated through hole and the lead 22.

While the preferred embodiment of the invention has been described, it will be apparent to those skilled in the art that various changes can be made in the embodiment of a surface mount package without departing from the spirit of the invention. Such modifications are within the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a front view of a prior art surface mount package.

FIG. 2 shows a cross-sectional view of the package shown in FIG.

FIG. 3 shows a bottom view of the package shown in FIG.

FIG. 4 shows a side view of the package when a long lead device is attached.

FIG. 5 shows a front view of the package of the present invention.

FIG. 6 shows a cross-sectional view of the package shown in FIG.

FIG. 7 shows a bottom view of the package shown in FIG.

FIG. 8 shows a side view of the package when a long lead device is attached.

FIG. 9 shows a cross-sectional view of a package with a long lead device folded inside.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lead device 12 Lead 20 Substrate 22 Groove 24 Via hole 30 Insulating substrate 34 Via hole 36 Bottom pad

Claims (5)

[Claims] An insulating substrate; at least one via hole passing through the substrate for inserting lead wires;
At least one long lead consisting of a solder material plated along the walls of the via holes soldered to the lead wires and extending to flat solder pads along the bottom of the substrate surface mounted to a motherboard Surface mount package for electronic devices with wires. 2. The method of claim 1, wherein there are two via holes.
A surface mount package for an electronic device as described. 3. The surface mount package for an electronic device according to claim 1, wherein said lead wire is inserted to a depth not deeper than a thickness of the substrate. 4. The surface mount package for an electronic device according to claim 1, wherein said lead wire is folded back inside said via hole. 5. The solder material according to claim 1, wherein said solder material is a tin-lead alloy.
A surface mount package for an electronic device as described.