JPH0428253A - Semiconductor device - Google Patents

Abstract

PURPOSE:To enable protrusions to be lessened in arrangement pitch by a method wherein protrusions or recesses are formed on the underside of a package base, a part of a through-hole is provided along the protrusion or the recess, and a through-hole land is formed semicircular. CONSTITUTION:Square protrusions 6 are arranged in lattice on the underside of a package base 1 and formed in an integral structure with the base 1. Part of through-holes 7 communicating with an inner lead 3 are formed in the opposed side faces of the protrusions in semicylinders respectively, and a semicircular through-hole land 8 connected to the through-hole 7 is provided to the underside of the protrusion 6 as an external lead-out electrode. In an actual manufacturing process, the through-hole 7 and the land 8 are provided to the base 1, the part other than protrusions is removed by cutting, the protrusions 6, the through-holes 7, and the lands 8 are left unremoved, and the protrusion 6 is formed as high as 1-2mm. By this setup, an arrangement pitch can be reduced to nearly a half of the diameter of the land 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device in which the external lead-out electrodes of a packaged semiconductor device are improved.

[Conventional technology]

Conventional semiconductor devices, as typified by PGA (bin grid array), have multiple pins protruding from the bottom of the package, these pins are inserted into holes provided on the printed circuit board for mounting, and the pins are soldered or otherwise soldered. It is implemented by connecting. FIG. 3 shows an example of this, in which a semiconductor element 12 is mounted within a package base 11, and internal leads 1
3 with a wire 14. The upper part of this package base 11 is sealed with a cap 15, and a plurality of external lead-out pins 19 arranged in a grid form are projected from the lower surface and are electrically connected to the internal leads 13.

However, the semiconductor device having this configuration is not suitable for double-sided surface mounting, which is mainstream in recent years, because the external lead-out pins 19 are inserted through the mounting printed circuit board.

For this reason, a semiconductor device shown in FIG. 4 has conventionally been proposed. This semiconductor device is shown in FIGS. 4(a) and (b).
As shown in the cross-sectional view and bottom view, respectively, flat external lead-out electrodes 18 are arranged in a grid pattern on the lower surface of the package base 11, and the external lead-out electrodes 18 are electrically connected to the internal leads 13. In this case, the external lead electrode 18 and the internal lead 13 are connected through the through hole 17 provided in the package base 11, and the external lead electrode 18
is configured as a through-hole land of the through-hole 17.

In this semiconductor device, an external lead-out electrode 17 is soldered to a conductor pattern formed on the surface of a printed circuit board for mounting.
Since it is only necessary to connect the two sides, it becomes possible to support double-sided surface mounting, which has become mainstream in recent years.

[Problem to be solved by the invention]

Although the semiconductor device shown in FIG. 4 is compatible with double-sided surface mounting, since the external lead-out electrode 18 is configured as a through-hole land, its arrangement pitch is the same as that of the through-hole 17. This is determined by the diameter of the hole land 18, making it difficult to miniaturize it. For example, with current technology, the array pitch dimension is approximately 0.8
It is difficult to reduce the thickness to less than mm.

For this reason, as the number of pins in semiconductor devices increases, it becomes necessary to increase the space for arranging the external lead-out electrodes 18, and as a result, there is a problem in that the dimensions of the package increase.

An object of the present invention is to provide a semiconductor device in which the external lead-out electrodes are miniaturized and the number of pins is increased without increasing the size of the package.

[Means to solve the problem]

In the semiconductor device of the present invention, a protrusion or a recess is formed on the lower surface of a package base in which a semiconductor element is mounted, and a part of a through hole electrically connected to the semiconductor element is formed along a side surface of the protrusion or recess. A through-hole land is formed in a semicircular shape and serves as an external lead-out electrode connected to the through-pole.

[Effect]

According to the present invention, by forming the through hole along the side surface of the protrusion or the recess and forming the through hole land in a semicircular shape, the arrangement pitch of the through hole land as an external lead-out electrode can be reduced to approximately 1/2. It is possible to increase the number of pins without increasing the size of the package.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, and FIG.
is a vertical cross-sectional view, and FIG. 2(b) is a bottom view thereof. In these figures, reference numeral 1 denotes a package base, on which a semiconductor element 2 is mounted in a concave portion of its upper surface, and internal leads 3 are arranged around this semiconductor element 2. The electrodes of the semiconductor element 2 and the internal leads 3 are electrically connected by wires 4, and the inside is sealed with a cap 5 fixed to the upper part of the package base 1.

Further, on the lower surface of the package base 1, a plurality of rectangular protrusions 6 are arranged in a grid pattern and are integrated into the package base 1. On the corresponding side surfaces of these protrusions 6, a part of through hole 7 connected to the internal lead 3 is formed in a semi-cylindrical shape, and on the lower surface of the protrusion 6, these through holes are used as external lead-out electrodes. A semicircular through-hole land 8 connected to the land 7 is formed.

Note that when actually manufacturing this configuration, after forming the through holes 7 and the through hole lands 8 on the package base l whose lower surface is flat, the parts other than the protrusions 6 are ground, and the protrusions 6. The through hole 7 and through hole land 8 may be left. The height of the protrusion 6 is 1 to 2 mm.
Good to have.

In the semiconductor device having this configuration, surface mounting can be performed by bringing the lower surface of the protrusion 6 into contact with the conductor pattern of the mounting printed circuit board and soldering using the through-hole land 8. At this time, solder the through hole land 8
By climbing up from the hole to the semi-cylindrical through hole 7, a connection with sufficient strength can be achieved. Of course, double-sided surface mounting, which has become mainstream in recent years, is also possible.

In this semiconductor device, the through hole 7 and the through hole land 8 are formed on the side surface and the bottom surface of the protrusion 6, and the through hole land 8 as an external lead-out electrode is formed in a semicircular shape, so that the arrangement thereof is The pitch can be reduced to approximately 1/2 of the diameter of the through hole land 8. Thereby, the space occupied by the external lead-out electrodes can be reduced, and even if the semiconductor device has a large number of pins, it is possible to prevent the package from increasing in size.

FIG. 2 shows a second embodiment of the present invention, and FIG.
is a cross-sectional view, and FIG. 3(b) is a bottom view.

Note that the same parts as in the first embodiment are given the same reference numerals.

In this embodiment, a circular recess 6A is formed on the lower surface of the package base 1, a part of the through hole 7A is formed in a semi-cylindrical shape on the opposite side of the recess 6A, and the A semicircular through hole land 8A connected to the through hole 7A is formed respectively. Note that the depth of the recess 6A is approximately 1 to 2+ nm.

In this embodiment as well, a sufficiently strong connection can be achieved by connecting the through-hole land 8A to the mounting printed circuit board with solder or the like and letting the solder creep up through the through-hole 7A. In addition, since the through holes 7A and through hole lands 8A are formed in a semicylindrical shape and a semicircular shape on the side surface of the recess 6A and the lower surface of the package base 1 as the end surface thereof, respectively, the arrangement pitch of the through holes 7A and the through hole lands 8A is adjusted. It can be reduced to approximately 1/2 of the diameter. As a result, it is possible to cope with an increase in the number of pins without increasing the size of the package, which is the same as in the first embodiment.

〔Effect of the invention〕

As explained above, the present invention forms a through hole along the side surface of a protrusion or recess provided on the lower surface of a package base, and forms a through hole land in a semicircular shape, so that it can be used as an external lead-out electrode. The arrangement pitch of the through-hole lands can be reduced to approximately 1/2, making double-sided surface mounting possible, and also having the effect of realizing a large number of bins without increasing the size of the package.

[Brief explanation of drawings]

1 shows a first embodiment of the present invention, FIG. 1(a) is a sectional view, FIG. 2(b) is a bottom view, and FIG. ) is a sectional view, FIG. 3(b) is a bottom view, FIG. 3 is a sectional view of an example of a conventional semiconductor device, FIG. 4 is another example of a conventional semiconductor device, and FIG. 4(a) is a sectional view. FIG. 3B is a bottom view. 1...Package base, 2...Semiconductor element, 3.
...Internal lead, 4...Wire, End...Cap, 6
...Protrusion, 6A...Concavity, 7.7A...Through hole, 8.8A...Through hole land, 11...
Package base, 12... Semiconductor element, 13...
Internal lead, 14... wire, 15... cap,
17...Through hole, 18...Through hole land, 19...External lead-out bin. Figures (a) (b) Figure 2 (a) (b) Figure 3 Figure 4 (a) (b)

Claims (1)

[Claims] 1. A semiconductor element is mounted inside a package base, a through hole electrically connected to the semiconductor element is extended to the lower surface of the package base, and a through hole land is provided as an external lead electrode at the lower end of the through hole. In the formed semiconductor device, a protrusion or a recess is formed on the lower surface of the package base, a part of the through hole is formed along a side surface of the protrusion or the recess, and the through hole land is formed in a semicircular shape. A semiconductor device characterized in that: