JPH04367257A - Ic package - Google Patents

Abstract

PURPOSE:To protect lead terminals of an IC using gull-wing type lead terminals which protrude from the package of the IC from being bent and improve the penetration of flux, etc., at the time of mounting the IC package on a substrate by soldering. CONSTITUTION:Protruding sections 3 which protrude by the same amount as the downward protruding amounts of lead terminals 2 are provided on the lower surface of a package 1. Since the sections 3 are provided on the lower surface of the package 1 and a gap is secured between the substrate 4 and package, flux, etc., easily penetrate at the time of mounting the package 1 on a substrate 4 by soldering and the mounting quality of the package 1 is improved. In addition, this IC package must meet the request of an improvement in the accuracy of the lead terminals in view of the recent tendency of reducing the thickness of lead terminals day by day, because the bending of the leads can be prevented and the surface mounting quality of the package is improved due to the protruding sections 3 which protrude by the same amount as the protruding amount of lead terminals on the lower surface of the package.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to IC packages.

0002

2. Description of the Related Art Conventionally, an IC package has a shape in which lead terminals 2 protrude from the bottom surface of the package 1, as shown in FIG.

0003

[Problems to be Solved by the Invention] In the conventional IC package described above, as shown in FIG. 2, the gull wing type lead terminals 2 and the lower surface of the package 1 have good permeability to aqueous flux during surface mounting with soldering. In order to do this, the package 1 is lifted up by the lead terminals 2 so as to create a gap between the mounting board 4 and the package 1. Therefore, the lead terminal has a structure in which it protrudes from the IC package, and there is a drawback that pressure is easily applied to the lead terminal, causing the lead to bend.

0004

[Means for Solving the Problems] The IC package of the present invention has lead terminals on the bottom surface of the package in order to protect the gull wing type lead terminals from lead bending and to facilitate penetration of flux etc. during surface mounting with soldering. It has a protrusion that is the same amount as the downward protrusion.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1A is a front view of an embodiment of the present invention, and FIG. 1B is a bottom view. A protrusion 3 is provided on the lower surface of the IC package 1 as shown in the figure. Therefore, when the IC package 1 is soldered and mounted on the mounting board 4, the lead terminals 2 come into contact with the mounting board 4, and at the same time, the protrusion 3 from the bottom surface of the IC package 1 also comes into contact. Since the protrusion 3 supports the IC package 1 on the mounting board, the lead terminals 2 can be prevented from bending even if pressure is applied from above the package.

[0006]

[Effects of the Invention] As explained above, the present invention provides a protrusion on the bottom surface of an IC package, so that water-soluble flux, etc. can easily penetrate when surface mounting the IC package on a mounting board by soldering. It is possible to secure a gap, which improves the mounting quality.Also, with the miniaturization of lead terminals that are becoming stronger day by day, there is a demand for improved accuracy of lead terminals. The protruding portion serves to prevent lead bending and has the effect of improving surface mounting quality.

[Brief explanation of drawings]

FIG. 1 is an outline diagram of an embodiment of the present invention.

FIG. 2 is an external view of a conventional example.

[Explanation of symbols]

1 Package 2 Lead terminal 3. Protruding part 4 Mounting board

Claims (1)

[Claims] [Claim 1] An IC package characterized in that the shape of the lead terminals protruding from the package is a gull wing type, and a protrusion is provided on the bottom surface of the package.
C package.