Active solid-state devices (e.g. – transistors – solid-state diode – Lead frame – On insulating carrier other than a printed circuit board
Reexamination Certificate
1998-06-16
2001-07-17
Potter, Roy (Department: 2822)
Active solid-state devices (e.g., transistors, solid-state diode
Lead frame
On insulating carrier other than a printed circuit board
C257S778000, C438S108000, C438S123000
Reexamination Certificate
active
06262473
ABSTRACT:
TECHNICAL FIELD
The invention relates to a semiconductor device and a method of making the same, a circuit board, and also a film carrier tape, and, in particular, to a film carrier tape and semiconductor device wherein the package size is close to the chip size, a method of making the same, and a circuit board.
BACKGROUND ART
If high-density mounting of semiconductor devices is to continue, bare-chip mounting would be ideal. However, quality assurance and handling are difficult in the bare chip state. A packaging method called CSP (chip scale/size package) has been developed to provide a package that has a size when packaged that is close to the chip size. This CSP type of semiconductor device has been developed in various forms; in one of them, a flexible substrate is provided on an active surface side of a semiconductor chip and a plurality of external electrodes are formed on that flexible substrate. With this semiconductor device, the external electrodes are provided within the area of the semiconductor chip, so that it does not have the “outer leads” that extend outward from the side surfaces of the package itself, as in a QFP (quad flat package) or TCP (tape carrier package), for example.
In a CSP type of semiconductor device that uses a flexible substrate, it is known to inject resin between the active surface of the semiconductor chip and the flexible substrate to absorb thermal stresses, as disclosed in, for example, International Publication WO95/08856.
However, various difficulties occur during the resin injection. For example, the resin is injected between the semiconductor chip and the flexible substrate, in other words, into a cramped region between the other components, and thus it is easy for air (air bubbles) to remain therein. If that should happen, the air (air bubbles) could expand at high temperatures and under high humidity, causing cracking. It is also difficult to stop the resin from flowing out from between the semiconductor chip and the flexible substrate.
The invention was devised in order to solve the above described l problems and its objective is to provide a film carrier tape and a semiconductor device, a method of making the same and a circuit board, wherein resin is readily injected in a favorable state between the semiconductor chip and the flexible substrate.
DISCLOSURE OF INVENTION
(1)The method of making a semiconductor device in accordance with the invention comprises:
a step of disposing a flexible substrate having a plurality of connection leads and a plurality of holes above a semiconductor chip to form a gap; and
a step of injecting resin into the gap through at least one of the holes while removing air from at least one of the remainder of the holes.
With the invention, if resin is injected between the semiconductor chip and the flexible substrate to form a resin seal, air escapes from a hole making it difficult for air to remain in the resin. This makes it possible to obtain a semiconductor device that is more reliable at high temperatures and under high humidity.
(2)The above making method could be modified such that:
the holes comprise a central hole located at substantially the center of the semiconductor chip; and
the resin is injected through the central hole.
(3)The above making method could be modified such that:
the flexible substrate is larger than the semiconductor chip;
the holes comprise a bonding hole formed above electrodes of the semiconductor chip; and
the making method further comprises:
a step of connecting the connection leads and the electrodes through the bonding hole; and
a step of injecting the resin through the bonding hole onto an active surface comprising the connected electrodes of the semiconductor chip.
(4)The above making method could be modified such that:
there is a time difference between the injection of the resin through the central hole and the injection of the resin through the bonding hole.
(5)The above making method could be modified such that:
the holes comprise a resin-stopping hole formed above an end portion of the semiconductor chip; and
the resin-stopping hole stops the spreading of resin injected into the gap.
(6)The above making method could be modified such that:
the resin-stopping hole has a rectangular shape, one inner peripheral edge thereof is located outward of an outer peripheral edge of the semiconductor chip, and another edge opposite to the one inner peripheral edge is located inward of the outer peripheral edge of the semiconductor chip.
(7)The above making method could be modified such that:
the resin-stopping hole is formed above the electrodes of the semiconductor chip, and the connection leads and the electrodes are connected through the resin-stopping hole.
(8)The above making method could be modified such that:
part of the film carrier tape is used as the flexible substrate; and the making method comprises the step of separating the film carrier tape into an Individual piece, after the resin is injected.
(9)The above making method could comprise the step of forming the film carrier tape.
(10)With the above making method, the step of forming the film carrier tape could comprise:
a step of forming a conductive pattern on a film to connect together in a conductive state all of the connection leads connected by a plurality of connection portions formed within a region to be sealed in resin, a plating lead formed outside the resin-sealed region, and a representative lead provided extending from the plating lead and connected at an intersection portion to any one of the connection leads;
a step of electroplating the conductive pattern through the plating leads; and
a step of punching out the connection portions and the intersection portion.
(11)The above making method could be modified such that:
the connection portions and the intersection portion are punched out at the same time.
(12)The above making method could be modified such that:
the connection portions and the intersection portion are punched out one by one.
(13)The method of making a film carrier tape in accordance with the invention comprises:
a step of forming a conductive pattern on a film to connect together in a conductive state all of:
connection leads connected by a plurality of connection portions formed within a region to be sealed in resin, a plating lead formed outside the resin-sealed region, and a representative lead provided extending from the plating lead and connected at an intersection portion to any one the connection leads;
a step of electroplating the conductive pattern through the plating lead; and
a step of punching out the connection portions and the intersection portion.
With the invention, if resin is injected between the semiconductor chip and the film carrier tape to form a resin seal, air escapes from a hole making it difficult for air to remain in the resin. This makes it possible to fabricate a semiconductor device with an improved reliability at high temperatures and high humidity.
(14)The above making method could comprise a step of forming a central hole in the film located substantially at a center of the semiconductor chip.
(15)The above making method could comprise a step of forming a bonding hole in the film located above electrodes of the semiconductor chip.
(16)The above making method could comprise a step of forming a resin-stopping hole in the film located above an end portion of the semiconductor chip.
(17)The above making method could be modified such that:
the connection portions and the intersection portion are punched out at the same time.
(18)The above making method could be modified such that:
the connection portions and the intersection portion are punched out one by one.
The semiconductor device in accordance with the invention comprises:
a semiconductor chip having a plurality of electrodes;
a flexible substrate located above and aligned with said semiconductor chip with a predetermined distance therebetween, said flexible substrate having a plurality of holes;
pad portions formed on said flexible substrate and connected to said electrodes; and
resin located betwee
Oliff & Berridge PLC.
Potter Roy
Seiko Epson Corporation
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