Semiconductor Device Package Having Particular Lead Structure for Mounting Multiple Circuit Boards

1. Field of the Invention

The present invention relates to a semiconductor device and a method of mounting the same and, more particularly, to the configuration of a lead of a semiconductor device and a method of mounting the semiconductor device having the lead of such a configuration.

2. Description of the Background Art

FIG. 1 is a partially cutaway perspective view showing a conventional DIL (Dual In Line Package) type semiconductor device which has leads arranged in parallel and extending downward from opposite sides of a package. Referring to FIG. 1, this DIL type semiconductor device 1a comprises a semiconductor element 2 fixed on a die pad 3 for supporting the semiconductor element 2 by means of solder material 4. The semiconductor element 2 has electrodes (not shown) which are connected with leads 5 through thin metal wires 6. Portions of the leads 5 to be connected with the wires 6 are provided with plating such as Ag plating in order to ensure the connection. The semiconductor element 2 and the wires 6 are sealed with mold resin 7 which forms a plastic package for protection against external forces. After the completion of the package 7, the leads 5 are cut away from a lead frame (not shown) and ends 5a of the leads 5 projecting from the package 7 are bent perpendicularly to the package 7.

FIG. 2B is a front view showing the DIL type semiconductor device 1a mounted on a printed circuit board 8. FIG. 2C is a side view of FIG. 2B and FIG. 2A is a fragmentary enlarged view of FIG. 2B. The leads 5 are inserted into through holes 11 of the board 8 from the upper side of the board 8, and then solder 10 is supplied in the through holes 11 from the lower side of the board 8 to connect the leads 5 with leads 9. Thus the semiconductor device 1a is mounted on the board 8. The leads 9 are connected with other devices and the like (not shown) mounted on the board 8 through a wiring pattern (not shown) formed on the board 8.

FIG. 3 is a partially cutaway perspective view showing a conventional ZIL (Zigzag In Line Package) type semiconductor device which has leads extending from one side of a package which are bent alternately on two planes in a zigzag manner. This ZIL type semiconductor device 1b is mounted on a printed circuit board 8 as shown in FIG. 4, wherein FIG. 4B is a front view, FIG. 4C is a side view of FIG. 4B and FIG. 4A is a fragmentary enlarged view of FIG. 4B. Reference numerals 2 to 11 in FIG. 3 and FIG. 4 denote the same components as in FIG. 1 and FIG. 2.

The DIL type semiconductor device shown in FIG. 1 and the ZIL type semiconductor device shown in FIG. 3 are called through hole devices because these devices are mounted on the board 8 by inserting the leads 5 into the through holes 11.

FIG. 5 is a partially cutaway perspective view showing a conventional SOP (Small Outline Package) type semiconductor device which has steplike leads arranged in parallel which are extending from opposite sides of a package. This SOP type semiconductor device 1c is mounted on a printed circuit board 8 as shown in FIG. 6, wherein FIG. 6B is a front view, FIG. 6C is a side view of FIG. 6B and FIG. 6A is a fragmentary enlarged view of FIG. 6C. Reference numerals 2 to 10 in FIG. 5 and FIG. 6 denote the same components as in FIG. 1 to FIG. 4.

The SOP type semiconductor device shown in FIG. 5 is called a surface mounting type device (SMD) because this device is mounted on the board 8 without through holes.

Disadvantageously, the conventional semiconductor devices structured as hereinbefore described can not be mounted across a plurality of printed circuit boards not lying on the same plane.

A semiconductor device in accordance with the present invention comprises a semiconductor element, a package for sealing the semiconductor element and leads electrically connected with the semiconductor element, the leads projecting from at least two (first and second) sides of the package and being bent in a zigzag manner so that the ends of the leads lie on at least two (first and second) planes.

This semiconductor device may be mounted across a plurality of printed circuit boards in accordance with a method of mounting a semiconductor device according to the present invention, comprising the steps of preparing first and second printed circuit boards, fixing a first group of the leads projecting from the first side of the package to the first printed circuit board, and fixing a second group of the leads projecting from the second side of the package to the second printed circuit board.

This semiconductor device may also be mounted across a plurality of printed circuit boards in accordance with a method of mounting a semiconductor device according to the present invention, comprising the steps of preparing first and second printed circuit boards, fixing a first group of the leads lying on the first plane to the first printed circuit board, and fixing a second group of the leads lying on the second plane to the second printed circuit board.

Accordingly, it is an object of the present invention to provide a semiconductor device and a method of mounting the same wherein the semiconductor device can be mounted across a plurality of printed circuit boards not lying on the same plane.

These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

FIG. 1 is a partially cutaway perspective view showing a conventional DIL type semiconductor device;

FIG. 2A to FIG. 2C are views showing the DIL type semiconductor device mounted on a printed circuit board;

FIG. 3 is a partially cutaway perspective view showing a conventional ZIL type semiconductor device;

FIG. 4A to FIG. 4C are views showing the ZIL type semiconductor device mounted on a printed circuit board;

FIG. 5 is a partially cutaway perspective view showing a conventional SOP type semiconductor device;

FIG. 6A to FIG. 6C are views showing the SOP type semiconductor device mounted on a printed circuit board;

FIG. 7 is a partially cutaway perspective view showing a first embodiment of a semiconductor device in accordance with the present invention;

FIG. 8 is a partially cutaway perspective view showing the semiconductor device of the first embodiment before the completion thereof;

FIG. 9A to FIG. 9C are plane, side and front views, respectively, showing the semiconductor device of the first embodiment;

FIG. 10A to FIG. 10C and FIG. 11A to FIG. 11C are views showing the semiconductor device of the first embodiment mounted across two printed circuit boards;

FIG. 12 is a partially cutaway perspective view showing a second embodiment of the semiconductor device in accordance with the present invention;

FIG. 13 is perspective view showing a third embodiment of the semiconductor device in accordance with the present invention; and

FIG. 14A to FIG. 14C are plane, side and front views, respectively, showing a fourth embodiment of the semiconductor device in accordance with the present invention.

FIG. 7 is a partially cutaway perspective view showing an embodiment of a semiconductor device in accordance with the present invention. Referring to FIG. 7, this semiconductor device 1 comprises a semiconductor element 2 fixed on a die pad 3 for supporting the semiconductor element 2 by means of solder material 4. The semiconductor element 2 has electrodes (not shown) which are connected with leads 5 through thin metal wires 6. Portions of the leads 5 to be connected with the wires 6 are provided with a plating such as an Ag plating in order to ensure the connection. The semiconductor element 2 and the wires 6 are sealed with mold resin 7 which forms a plastic package for protection against external forces. After the completion of the package 7, the leads 5 are cut away from a lead frame (not shown). At this stage, the semiconductor device 1 has a structure shown in FIG. 8.

After that, the leads 5 are alternately bent upward and downward as shown by arrows in FIG. 8. Thus, there is completed the semiconductor device 1, wherein the leads 5 are projected from opposite sides of the package 7 and are alternately bent upward and downward in a zigzag manner. FIG. 9A is a plane view of the completed semiconductor device 1 and FIG. 9B and FIG. 9C are side and front views of FIG. 9A, respectively. Ends of leads 5b of the leads 5 lie on a first plane in the top surface side of the semiconductor device 1 and ends of leads 5c of the leads 5 lie on a second plane in the rear surface side of the semiconductor device 1.

The semiconductor device 1 structured as hereinbefore described may be mounted across two printed circuit boards 8a and 8b as shown in FIG. 10, wherein FIG. 10A is a front view, FIG. 10B is a side view and FIG. 10C is a plane view. In FIG. 10C, the upper printed circuit board 8a is deleted for the purpose of illustrating the semiconductor device 1.

Referring to FIG. 10, the semiconductor device 1 is placed between and perpendicularly to the two parallel printed circuit boards 8a and 8b. A half of the leads 5 projecting from one side of the package which are arranged in an alternate zigzag manner are inserted in through holes 11 of the upper board 8a to be fixed to the board 8a by means of solder 10 supplied in the through holes 11. A remaining half of the leads 5 projecting from the other side of the package which are arranged in an alternate zigzag manner are inserted in through holes 11 of the lower board 8b to be fixed to the board 8b by means of solder 10 supplied in the through holes 11.

The semiconductor device 1 may also be mounted across two printed circuit boards 8a and 8b as shown in FIG. 11, wherein FIG. 11A is a plane view, FIG. 11B is a side view and FIG. 11C is a front view. In FIG. 11A, the upper printed circuit board 8a is deleted for the purpose of illustrating the semiconductor device 1.

Referring to FIG. 11, the semiconductor device 1 is placed between and parallel to the two parallel printed circuit boards 8a and 8b. A half of the leads 5 lying on one plane in the top surface side of the device 1 are fixed on the upper board 8a by means of solder 10. A remaining half of the leads 5 laying on the other plane in the rear surface side of the device 1 are fixed on the lower board 8b by means of solder 10.

Thus, the semiconductor device 1 can be mounted across the two parallel printed circuit boards 8a and 8b which are perpendicular to or parallel to the leads 5 of the semiconductor device 1.

The plastic package 7 may be replaced by a ceramic package. FIG. 12 is a partially cutaway perspective view showing another embodiment of the semiconductor device in accordance with the present invention, wherein a ceramic package 12 is employed. The ceramic package 12 is composed of two parts of an upper part 12a and a lower part 12b. Leads 5 extend outside through between the upper and lower parts 12a and 12b of the ceramic package 12. Leads 5 and the upper and lower parts 12a and 12b of the ceramic package 12 are attached by means of sealant 13. A metal cover 14 is provided on the upper part 12a of the ceramic package 12 to close a cavity provided in the ceramic package 12. Other structures are the same as those of the semiconductor device shown in FIG. 7.

FIG. 13 is a perspective view showing a third embodiment of the semiconductor device in accordance with the present invention, wherein leads 5 are projected from four sides of a package 7 as compared with that in which the leads 5 are provided only at two sides (opposite sides) of the package 7, as shown in the first and second embodiments. Other structures are the same as those of the semiconductor device shown in FIG. 7.

FIG. 14A to FIG. 14C are plane, side and front views, respectively, showing a fourth embodiment of the semiconductor device in accordance with the present invention, wherein leads 5 are bent in a zigzag manner so as to lie on four planes as compared with that in which the leads 5 lie on two planes, as shown in the first to third embodiments. Other structures are the same as those of the semiconductor device shown FIG. 7.

Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation. The spirit and scope of the present invention should be limited only by the terms of the appended claims.