JPH04368160A - Semiconductor package - Google Patents

Abstract

PURPOSE:To provide a semiconductor package which can prevent failure of solder bridge at the time of mounting a substrate due to microminiaturization of outer lead pitch of a semiconductor package. CONSTITUTION:A shorter outer lead 4 and a longer outer lead 5 are alternately provided for locating in zig-zag the adjacent contact surfaces 4a, 5a between the outer leads 4, 5 and mounting substrates 6, 7 of a semiconductor package. Thereby microminiaturization of outer lead pitch may be realized and a multi- pin and small size semiconductor package can be obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor package, and more particularly to a mounting surface of an outer lead thereof.

0002

2. Description of the Related Art FIGS. 4 and 5 show this type of conventional semiconductor package, in which FIG. 4 is a plan view, FIG. 5 is a side view, and FIG.
FIG. 2 is a plan view showing a mounting pad of a substrate on which the semiconductor package is mounted. In the figure, 1 is not shown, but for example, a semiconductor element chip is bonded onto a die pad, and a plurality of bonding pads provided on the semiconductor element chip and internal leads arranged around the die pad are connected with thin metal wires and sealed with resin. In this type of semiconductor package, 2 is an extension of the inner leads, and outer leads 2 for external connection protrude at uniform lengths from the outer periphery of the semiconductor package 1 and are arranged at minute intervals, and 2a is the bonding surface thereof. Reference numeral 3 denotes a mounting pad of the mounting board to which the bonding surface 2a of the outer lead 2 of the semiconductor package 1 is bonded.

Next, the operation will be explained. The semiconductor package 1 configured as described above is mounted with the bonding surface 2a of the outer lead 2 positioned on the mounting pad 3 of the mounting board through solder.

0004

[Problems to be Solved by the Invention] Since conventional semiconductor packages are constructed and mounted as described above, as the outer lead pitch becomes finer, adjacent bonding surfaces become closer together during mounting, resulting in solder bridging problems, that is, Adjacent parts may come into contact due to solder leakage, etc. This has been one of the obstacles to increasing the number of pins and reducing the size of semiconductor packages.

The present invention was made to solve the above-mentioned problems, and its object is to obtain a semiconductor package with a large number of pins and a reduced size without causing solder bridging defects during mounting.

[0006]

[Means for Solving the Problems] A semiconductor package according to the present invention has long and short outer leads arranged alternately so that the bonding surfaces of the outer leads bonded to the mounting pads are staggered between adjacent ones. It is.

[0007]

[Function] The outer leads in the semiconductor package of the present invention are arranged in a staggered manner so that a distance between adjacent surfaces of the outer leads and the bonding surfaces with the mounting substrate is ensured, thereby preventing problems caused by solder bridging.

[0008]

【Example】

Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. 1 and 2 show a semiconductor package in Embodiment 1 of the present invention, FIG. 1 is a plan view thereof, FIG. 2 is a side view thereof,
FIG. 3 is a plan view showing a mounting pad of a substrate on which the semiconductor package is mounted. In the figure, 1 is the same as the conventional example, so its explanation will be omitted. 4 is a short outer lead for external connection that has a bonding surface 4a and is arranged to protrude from the outer periphery of the semiconductor package 1 as an extension of the inner lead;
Reference numeral 5 denotes a long outer lead for external connection, which has a bonding surface 5a and is arranged to protrude from the outer periphery of the semiconductor package 1 as an extension of the inner lead, alternately with the short outer lead 4;
The joint surfaces 4a and 5a have a staggered shape with inner and outer positions, respectively. Reference numerals 6 and 7 designate mounting pads of the mounting board to which the bonding surface 4a of the short outer lead 4 and the bonding surface 5a of the elongated outer lead 5 are bonded, respectively.

Next, the operation will be explained. When the semiconductor package 1 formed with the short and long outer leads 4 and 5 as described above is mounted on the mounting pads 6 and 7 of the mounting board, the bonding surfaces thereof are positioned in a staggered manner between adjacent ones. This will ensure sufficient distance between the two. In addition, the short and long outer leads are made using a transfer molding device (not shown).
After sealing with resin, adjacent outer leads are cut from a semiconductor device lead frame (not shown) using a lead processing device (not shown) so that the lengths of the adjacent outer leads are alternately short and long. has completed semiconductor packages.

Example 2. In addition, in the above example 1, outer leads are drawn out in four directions (quad flood package).
Although the semiconductor package described above has been described, it may be a surface mount type (small outline package) semiconductor package with outer leads extending in two directions, etc., and the same effects as in the first embodiment can be obtained.

[0011]

[Effects of the Invention] As described above, according to the present invention, long and short outer leads are arranged alternately so that the bonding surfaces of the outer leads bonded to the mounting pads of the semiconductor package are staggered between adjacent ones. With this configuration, when mounting on a mounting board, the adjacent spacing between the contact surfaces can be ensured, and solder bridging problems can be prevented, resulting in the effect that a multi-pin, miniaturized semiconductor package can be obtained.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a semiconductor package in Example 1 of the present invention.

FIG. 2 is a side view showing Embodiment 1 of the present invention.

FIG. 3 is a plan view showing a mounting pad of a substrate on which the semiconductor package of Example 1 is mounted.

FIG. 4 is a plan view showing a conventional semiconductor package.

FIG. 5 is a side view showing a conventional semiconductor package.

FIG. 6 is a plan view showing a mounting pad of a substrate on which a conventional semiconductor package is mounted.

[Explanation of symbols]

1 Semiconductor package 4 Short outer lead 5　Long outer lead 6 Mounting pad of mounting board 7 Mounting pad of mounting board

Claims (1)

[Claims] 1. In a semiconductor package in which outer leads are arranged around the periphery at a fine pitch and mounted on a mounting pad of a mounting board, bonding surfaces of the outer leads that are bonded to the mount pads are staggered between adjacent ones. A semiconductor package characterized by alternately arranging short and long outer leads so that