JPS6292342A - Semiconductor package for surface mounting - Google Patents

Abstract

PURPOSE:To position a semiconductor package easily and positively at the time of mounting to a substrate by forming a projection, which is engaged with the substrate and conducts positioning to the substrate and the prevention of positional displacement, on the mounting surface side to the substrate of a mold. CONSTITUTION:In a semiconductor package 8 for mounting the surface, a projection 9, which is connected to a substrate 4 and performs positioning to a predetermined position to the substrate 4 and the prevention of positional displacement, is shaped on the mounting surface side to the substrate of a mold. The projection 9 is engaged with a hole 10, etc. for positioning being previously prepared in the substrate 4, thus easily positioning the package 9 positively with respect to a conductor pattern on the substrate 4.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is mounted at a predetermined position on the surface of a substrate having a conductive pattern on the surface, such as a printed circuit board, and a surface to which a lead wire is connected to the conductive pattern. Regarding semiconductor packages for mounting.

[Conventional technology]

The well-known 80F (8mol 0output Line Pa) is an example of a conventional surface mount semiconductor package.
Fig. 4 shows the outline of the ckage). In the figure, (1) is a mold that encapsulates a semiconductor (not shown), and (2) is made of, for example, plastic. (2) is a position mark for inputting and outputting signals with the encapsulated semiconductor, and the other half is a position mark for sequentially numbering the lead wires (2).

Figure 5 shows the above mold +11. IJ-do wire (2),
and a position mark (3) (hereinafter simply referred to as the package). The board 2 is, for example, a printed circuit board, and (6) is a conductor pattern printed on the surface of the board (4), (6) is an adhesive for fixing the package (8) on the board (4), (7) is cream solder printed on the conductor pattern (5) on the substrate (4).

Next, a method of mounting such a package (8) will be explained. The package (8) is mounted in alignment with the conductor pattern (5) on the substrate (4). This implementation involves a method in which humans align the positions by looking at the conductor pattern (5).

There is a method in which the position of the conductive pattern (5) is memorized in advance by a machine and the mounting is automatically performed according to the memorized information.

On the other hand, the second surface mount package (8) is fixed to the substrate (4) shown in FIG. 5(a) by the following two methods.

One method is to use an adhesive (6), which is placed on the substrate (4) and under the mold (1) of the package (8), as shown in Figures 5 (bl) and (cl). First, apply the adhesive.

Next, the package (8) is placed on a predetermined position on the board (4), and the package (8) is fixed at a predetermined position on the board (4).

After this, each lead wire (21 (21...) is soldered to the conductor pattern (5).Another method is as shown in Fig. 5 (b2) (C
As shown in 2), by the method using cream solder (7),
Apply cream solder (
7) Print out.

On top of that, each lead wire (2) (2) of the package (8)
Place...

This is a top view of a package (8) mounted on a conductor by heating with infrared rays, hot steam, or the like.

[Problem that the invention seeks to solve]

In the conventional mounting method using the surface mount semiconductor package (8), the surface of the printed circuit board (4) on which the surface mount semiconductor package (8) is mounted is almost flat even with the conductor pattern (5). Therefore, it is not possible to mechanically align the surface mount semiconductor package (8) to a predetermined position on the board (4), and if you try to mount it using an automatic mounting device, etc., it will be difficult to align it. This requires the development of extremely high-precision automatic equipment. Furthermore, even after the semiconductor package (8) is placed on the board (4), the semiconductor package (8) remains on the board (4) until it is soldered.
) is bonded with an adhesive (6) or the like, but there are problems in that even small vibrations can cause positional displacement. In other words, as understood from Figure 5 (bl) (C1),
After applying the adhesive (6) on the substrate (4), attach the substrate +41
In order to align the semiconductor package (8) against
A slow-drying adhesive must be used as the adhesive; therefore, the adhesive does not provide a strong bond until soldering, and even small vibrations can cause misalignment.

This invention was made in order to solve the above-mentioned problems. 2. It is possible to easily and reliably align the surface mounting semiconductor package with respect to the substrate, and to prevent misalignment even with small vibrations. With the goal.

[Means for solving problems]

A semiconductor package for surface mounting according to the present invention is a semiconductor package for surface mounting.

In a surface mount semiconductor package that is mounted at a predetermined position on the surface of a substrate having a conductive pattern on the surface and has lead wires connected to the conductive pattern, the surface mounting semiconductor package is engaged with the substrate and positioned at the predetermined position with respect to the substrate. A protrusion for preventing displacement is provided on the mounting surface of the mold to the substrate.

[Effect]

The surface mount semiconductor package company of the present invention is made by engaging the protrusion on the mounting surface side with a positioning hole etc. prepared in the board.

Easily and reliably aligns the surface mount semiconductor package with the conductor pattern on the board, and eliminates misalignment that is likely to occur between the time when the lead wires of the two surface mount semiconductor packages are connected to the conductor pattern on the board after mounting. prevent.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 is an external view of the entire surface mounting semiconductor package (8), in which (a) is a plan view, (b) is a front view, and (C
) is a side view; in these figures, (l) is the mold that encapsulates the semiconductor; (2) is the mold that inputs and outputs signals to and from the encapsulated semiconductor; (3)
(9) is a position mark for numbering each lead wire (2) in order, and (9) is a protrusion provided on the mold (1) to attach to the substrate (4) shown in Fig. 2, which will be described later. Provided on the mounting surface side.

FIG. 2 is an enlarged sectional view showing the surface mounting semiconductor package (8) attached to a substrate (4) such as a printed circuit board, and FIG. 3 is a plan view of the substrate (4). , (4) is a substrate for mounting the semiconductor package (8), for example, a printed circuit board. (5)
is a conductor pattern printed on this board (4), and O1 is a hole for alignment drilled in the printed board (4).

The surface mount semiconductor package shown in FIGS. 1(,)(b)(0) is mounted on the substrate shown in FIG. 3 as shown in FIG. 2. Each lead wire (2) of the two surface-mount semiconductor packages (8) is connected to a conductor pattern (5) printed on the substrate (4). The protrusion (9) of the two-surface mounting semiconductor package (8) fits into the positioning hole α1 drilled in the substrate (4). When mounting the surface mounting semiconductor package (8) on the substrate (4), first, the hole a1 of the substrate (4) serves as a guide and the semiconductor package (8) is mounted on the substrate (4).
) is mounted and positioned at the correct position on the substrate (4).

If the semiconductor package (8) is mounted in a stable position in this manner, even slight vibrations will not cause the semiconductor package (8) to shift relative to the substrate (4).

In the above embodiment, the position of the protrusion (9) is mold +1.
The one provided at the center of 1 when viewed from above is shown.

It is not necessary to provide it in the center, but on the substrate (4) of the mold (1).
It may be provided at any position on the mounting surface side. Also,
In the above embodiment, the shape of the protrusion (9) is conical, but the shape of the protrusion (9) does not have to be conical, but may be a so-called protrusion such as a bicylindrical shape or a triangular pyramid. . Further, in the above embodiment, the protrusion (9) is provided at only one location on the mounting surface side of the mold (1), but it may be provided at a plurality of locations instead of only at one location.

〔Effect of the invention〕

As described above, the present invention provides a surface mount semiconductor package that is mounted at a predetermined position on the surface of a substrate having a conductive pattern on its surface and has lead wires connected to the conductive pattern. Since a protrusion for positioning the semiconductor package at the predetermined position and preventing displacement is provided on the surface of the mold to be mounted on the substrate, the positioning of the semiconductor package for surface mounting on the substrate can be easily and reliably performed. Moreover, even if some vibration occurs after the two positions are aligned and before the lead wires of the semiconductor package are connected to the conductor pattern of the board, the semiconductor package will not be misaligned due to the vibration, and each lead of the semiconductor package will not be misaligned. The connection between the wire and the conductor pattern on the board is good, and furthermore, when using an automatic mounting machine etc. to mount the semiconductor package on the board, it is easy to position the semiconductor package on the board as described above. In addition, since it is performed accurately, there is no need to specially equip the automatic mounting machine itself with an expensive function device for positioning, and the semiconductor package can be accurately positioned at a predetermined position on the board using an inexpensive automatic mounting machine. This has advantages such as being able to accurately and reliably connect the lead wires to the conductor pattern on the board.

[Brief explanation of drawings]

Figures 1 to 3 are diagrams showing one embodiment of the present invention.
The figure is an external view, (a) is a plan view, (b) is a front view,
2(C) is a side view, FIG. 2 is an enlarged sectional view showing the surface mounting semiconductor package attached to the board, and FIG. 3 is a plan view of the board. Fig. 4 is an external view of an example of a conventional surface mount semiconductor package, in which (a) is a plan view, (b) is a front view, (C) is a side view, and Fig. 5 is an example of a conventional surface mount semiconductor package. This is a diagram showing the process of mounting and connecting to the board. (a
) is a side view of the board before mounting the semiconductor package,
(bl) is a side view showing the state in which adhesive is applied to the board;
(cl) is a side view showing the semiconductor package mounted in a predetermined position on the board with adhesive, (b2) is a side view showing cream solder applied to the conductor pattern of the board, and (c2) is the side view of the board. FIG. 3(d) is a side view showing a state in which lead wires of a semiconductor package are connected to a conductor pattern via cream solder; FIG. In the figure, (1) is a solder wire, (2) is a lead wire, (
4) is a substrate, (5) is a conductor pattern, (8) is a surface mounting semiconductor package, (9) is a protrusion, and 3 is a hole. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] In a surface mount semiconductor package that is mounted at a predetermined position on the surface of a substrate having a conductive pattern on the surface and has lead wires connected to the conductive pattern, the surface mounting semiconductor package is engaged with the substrate and positioned at the predetermined position with respect to the substrate. A semiconductor package for surface mounting, characterized in that a protrusion for preventing displacement is provided on the mounting surface side of the mold to the substrate.