Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Making electrical device
Reexamination Certificate
2000-08-08
2003-06-03
Huff, Mark F. (Department: 1756)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Making electrical device
C430S312000, C430S313000, C430S318000, C430S394000, C430S396000
Reexamination Certificate
active
06573028
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a semiconductor module substrate sheet that constitutes a semiconductor module with one or a plurality of semiconductor chips of monolithic IC's, hybrid IC's, multi-tip IC's, diodes, transistors, thyristors, or the like mounted thereon, a method for fabricating the semiconductor module substrate sheet and a semiconductor module constructed of the substrate sheet mounted with semiconductor chips mounted thereon.
BACKGROUND ART
Conventionally, a semiconductor package of a monolithic IC, a hybrid IC, a multi-tip IC, a diode, a transistor, a thyristor, or the like has been formed by punching by using a press, or by etching a metal conductor of a die pad and leads on which a semiconductor chip is mounted as represented by a lead frame, mounting the semiconductor chip on the die pad, and electrically connecting the electrode terminals of the semiconductor chip with inner lead sections of the leads by way of thin metal wires by bonding or similar means. Thereafter, the semiconductor chip and at least the inner lead sections on the through hole side are encapsulated and the outer lead sections of the leads are bonded by means of a die for the mounting of the semiconductor package on a printed wiring board.
However, the lead frame, which is required to support the semiconductor chip by the die pad and to be bent for the mounting thereof on the printed wiring board, has therefore, been required to have a rigidity. For the above reasons, the metallic lead frame has not been able to have a reduced thickness, and consequently, pure copper, which has good electrical conductivity, has been hard to use. Furthermore, the adjacent outer lead sections have connected portions partially connected with each other when the semiconductor chip or the like is encapsulated. Therefore, after the encapsulating process, a process has been required for cutting the connected portions (called the tie bar) with a die or the like, so the outer lead sections have independent pins.
In view of the above, there have been lately devised a number of various types of semiconductor packages
914
in which the lead material is not required to have rigidity, obviating the need for cutting the many tie bars during the fabricating process. One of the types is formed by bending a flexible substrate of a film
15
or the like provided with inner lead sections
5
and outer lead sections
6
(see FIG.
70
), bonding this to a substrate
13
of the semiconductor package
914
so that the outer lead sections
6
are formed on the rear surface of the substrate
13
and so that the inner lead sections
5
and the outer lead sections
6
are connected together by way of respective connection sections
7
provided on side surfaces of the substrate
13
. Thereafter, a semiconductor chip
10
is mounted on the substrate
13
, and the semiconductor chip
10
is connected with the inner lead sections
5
by way of wires
11
. Thereafter, the semiconductor chip
10
or the like is encapsulated with an encapsulating section
12
, allowing the semiconductor package
914
to be surface-mountable (see FIG.
71
).
However, the above method, which requires many fabricating steps including the formation of the inner lead sections and the like on a film and then the bending and bonding of the film, has disadvantageously been troublesome.
In recent years, some semiconductor packages such as IC's except for diodes, transistors, and thyristors, have been required to more seriously cope with high-density mounting of semiconductor chips. In accordance with this, the inner lead sections to be electrically bonded by wire bonding or similar method to the electrode terminals of the semiconductor chip are required to have an increased number of pins and narrower pitches. In the case of the semiconductor package having an increased number of pins and narrower pitches as described above, even a slight error in positional alignment occurring in the film bending and bonding stages cannot be ignored, and this positional alignment error disadvantageously has caused difficulties in maintaining the dimensional accuracy.
Accordingly, the object of the present invention is to solve the aforementioned issues and to provide a semiconductor module which can be fabricated in a reduced number of fabricating steps, a semiconductor module substrate sheet to be used for the fabricating process, and a method for fabricating the sheet.
DISCLOSURE OF INVENTION
In order to achieve the aforementioned object, the present invention is constructed as follows.
According to a first aspect of the present invention, there is provided a semiconductor module substrate sheet comprising an insulating substrate having a semiconductor chip placement region on which a semiconductor chip can be placed. A plurality of inner lead sections are formed on a surface identical to that of the semiconductor chip placement region of the insulating substrate and respectively electrically connected to a plurality of electrode terminals of the semiconductor chip placed on the semiconductor chip placement region so as to form a semiconductor module. A plurality of outer lead sections are formed on a surface opposite to that of the semiconductor chip placement region of the insulating substrate, and a plurality of connecting sections respectively connect the plurality of inner lead sections to the plurality of outer lead sections on a side wall surface of the insulating substrate.
According to a second aspect of the present invention, there is provided a semiconductor module substrate sheet as defined in the first aspect, comprising a recess of a size capable of receiving the semiconductor chip in the semiconductor chip placement region.
According to a third aspect of the present invention, there is provided a semiconductor module substrate sheet as defined in the first or second aspect, wherein the insulating substrate has through holes and the plurality of connecting sections are formed on side wall surfaces of the through holes.
According to a fourth aspect of the present invention, there is provided a semiconductor module substrate sheet as defined in the third aspect, wherein the through holes of the insulating substrate are arranged on the two opposite sides of the semiconductor chip placement region having a rectangular shape.
According to a fifth aspect of the present invention, there is provided a semiconductor module substrate sheet as defined in the third aspect, wherein the through holes of the insulating substrate are arranged on four sides of the semiconductor chip placement region having a rectangular shape.
According to a sixth aspect of the present invention, there is provided a semiconductor module substrate sheet as defined in the first or second aspect, wherein the insulating substrate has a recess at its edge, and the plurality of connecting sections are formed on a side wall surface of the recess.
According to a seventh aspect of the present invention, there is provided a semiconductor module substrate sheet as defined in the first or second aspect, wherein the plurality of connecting sections are formed on the side wall surface of the edge of the insulating substrate.
According to an eighth aspect of the present invention, there is provided a semiconductor module substrate sheet as defined in any one of the first through seventh aspects, wherein the plurality of inner lead sections are arranged so as to respectively extend from the plurality of connecting sections toward the semiconductor chip placement region, and the plurality of outer lead sections are arranged so as to respectively extend from the plurality of connecting sections toward a region corresponding to the semiconductor chip placement region on a rear surface of the substrate sheet.
According to a ninth aspect of the present invention, there is provided a semiconductor module substrate sheet as defined in any one of the third through fifth aspects, wherein the plurality of inner lead sections are arranged so as to respectively extend from the pluralit
Tsuji Koichiro
Yamamoto Kunitoshi
Chacko Davis Daborah
Huff Mark F.
Nissha Printing Co. Ltd.
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