JPH01268045A - Electronic component - Google Patents

Abstract

PURPOSE:To make it possible to implement a higher mounting density of flat package ICs and the like on a printed circuit substrate and the like, by forming the outermost ends of each planar attaching lead line as non-connecting terminal. CONSTITUTION:Planar attaching lead lines are provided in an electronic component having many legs such as a flat pack type packaged integrated circuit 6. In the electronic part, each outermost end of each planar attaching lead line is formed as a non-contact(NC) terminal 1. In general, many solder bridge parts 5 may be possibly formed at the outermost ends of the lead lines when lead frame terminals 2 are soldered in mounting on a printed circuit substrate. Since the terminal 1 is the NC terminal, the solder bridges do not affect on an intrinsic electric circuit. Since the area of each corner part of a resist hole 4a of the printed circuit substrate on which the flat package IC 6 is to be mounted can be used effectively, the higher density mounting can be performed, and the soldering work is made efficient.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-legged electronic component, such as a flat-pack package integrated circuit, having Y-faced leads.

[Conventional technology]

This type of multi-legged electronic component, in which the bottom and top surfaces are parallel flat plates, and lead terminals for soldering connectors etc. protrude parallel to the flat plate, is called a so-called flat pack package (hereinafter referred to as flat package). There is an integrated circuit (hereinafter abbreviated as IC) of the type shown in FIG.
A partial plan view of C is shown.

6 is a flat package IC (shown as a fill cut)
, 2 indicates each flat lead frame terminal, 3 indicates each conductor land for each terminal 2, 4 indicates a resist hole of the printed circuit board on which the IC 6 is to be mounted, and 8 indicates solder.

Reference numeral 7 denotes a solder pool land portion formed widely outwardly at each outermost end Y-2 of each flat lead row.

When mounting the [C6 on a printed circuit board, paste solder is applied to each conductor land 3.7, each lead 2 of the IC6 is aligned to each land, and a laser beam is applied. Alternatively, when the two are soldered together by infrared irradiation heating, etc., in each land portion 3 in the middle of the lead row, the paste-like solder that protrudes between each adjacent land will be removed during melting. Due to the cohesive force (surface tension) of , they are attracted to the lands on both sides and a normal solder joint is performed, but if the outermost land has the same shape as each land 3 in the middle, The overflowing paste-like solder remains on the board because the cohesive force during melting as described above only acts on one side, and the solder solidifies into a ball shape and moves, causing the solder to stick to the printed circuit board. This is provided to prevent the possibility of short circuits or poor insulation.

(Problem to be Solved by the Invention) However, in the conventional example as described above, an unnecessary area of the land pattern 7 is required at each corner of the IC 6, such as the solder pool land portion 7. There was a problem in that the inherent advantages of thin flat package ICs, which are suitable for high-density packaging, could not be fully exploited because the printed circuit board area could not be utilized.

Another problem is that when a flat package IC is poured into a flow tank, depending on the direction of flow, solder bridges are likely to occur at the ends of the pins of the flat package IC.

The present invention has been made in view of the problems of the conventional examples as described above, and aims to provide a means that enables higher density mounting of flat package ICs and the like on printed circuit boards, etc. .

[Means to solve the problem]

Therefore, in the present invention, each planar member of an electronic component such as a flat pack IC connects the outermost end of the lead row to a non-connection terminal (abbreviated as N) on mounting.
The purpose is to achieve the above object by forming a Cf4 child).

[Effect]

With the above configuration, the terminals at the outermost ends of the lead rows of the planar material are not used for mounting on printed circuit boards, etc., so the above-mentioned problems do not occur in this part, so it is possible to This eliminates the need for land areas, etc., and allows effective use of the conventional corner areas of the resist holes on the board, making it possible to implement higher-density mounting.
Soldering also makes work more efficient.

〔Example〕

The present invention will be explained below based on examples.

FIG. 1 shows a partial plan view of an embodiment of a flat package IC that best represents the features of the present invention, corresponding to FIG. 2 of the conventional example, and the same (equivalent) components as in FIG. , are represented by the same symbols.

(Configuration) In FIG. 1, 6 indicates a flat package IC 11.
According to the present invention, each plane member has a N
C (no connection) terminal, 2 is each lead frame terminal, 3 is,
Each land for the terminal 2, 4a, is a resist hole of a printed circuit board to be mounted, and 5 is a solder bridge portion formed at the outermost end of the lead row.

(Function) Next, in the above configuration, when soldering the lead frame 2 when mounting it on a printed circuit board, as described above, - numerically, solder bridging is performed at the outermost end of the lead row. Part 5 may occur frequently, but since this terminal 1 is an NC terminal, these solder bridges are
This method has no effect on the original electric circuit, and the area of each corner of the resist hole 4a of the printed circuit board on which the flat package IC is mounted can be used more effectively than in the conventional example. Therefore, the packaging density can be increased, and the efficiency of soldering can also be improved, contributing to a reduction in manufacturing costs.

(Effects of the Invention) As explained above, according to the present invention, since the planar material of electronic components such as flat pack ICs is configured so that the outermost end of the lead row is the NC terminal, the area of each corner can be utilized. ,
It enables high-density mounting on printed circuit boards, etc., and improves the efficiency of soldering work.

[Brief explanation of the drawing]

FIG. 1 is a partial plan view of an embodiment of a flat package IC according to the present invention, and FIG. 2 is a view corresponding to FIG. 1 of a conventional example. 1...NC terminal 2...Lead frame terminal 3...Land 5...Solder bridge portion 6...Flat package IC (? E Child Parts Applicant Canon Co., Ltd. 6 Flat Hard Jγ-Yoku I (- Partial Plan View of Royalty Fee 1 Figure

Claims (1)

[Claims] 1. A multi-legged electronic component such as a flat-pack packaged integrated circuit having rows of flat leads, characterized in that each outermost end of each row of flat leads is formed as a non-connection terminal.