Active solid-state devices (e.g. – transistors – solid-state diode – Lead frame – On insulating carrier other than a printed circuit board
Reexamination Certificate
1999-07-20
2003-12-16
Talbott, David L. (Department: 2827)
Active solid-state devices (e.g., transistors, solid-state diode
Lead frame
On insulating carrier other than a printed circuit board
C257S679000, C257S680000, C257S774000, C257S673000, C257S780000, C257S686000
Reexamination Certificate
active
06664616
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to semiconductor devices and the manufacturing methodology thereof; and, more particularly, the invention relates to technologies usefully applicable to high-density mountable semiconductor devices with tape carrier package (TCP) structures along with fabrication methods thereof.
In recent years, as portable or handheld electronic equipment, of reduced shape and thickness, and yet with much increased functionalities, is being developed for mass production, TCP technologies are becoming more and more important in the manufacture of solid-state integrated circuit (IC) packages for use in highly advanced electronic equipment with respect to the enhanced mountability of thickness-reduced or “thin” electronics components and also to the ability to increase the number of package pins.
The TCP is a package including a tape carrier having a plurality of conductive leads formed thereon in a repeated pattern, wherein a semiconductor chip is placed on or in the tape carrier with its electrode pads lamination-contacted with corresponding ones of the carrier leads for electrical interconnection therebetween, the semiconductor chip being sealed by a sealing resin material or the like.
Prior known TCPs typically have been designed so that the semiconductor chip being used is greater in thickness than the tape carrier, which would result in an increase in the mounting height of a multilayer tape structure wherein multiple unitary tape carriers are laminated on one another. One prior art approach to mount-height reduction has been described, for example, in Japanese Patent Application Laid-Open No. 63(1985)-52431 (“JP-A-63-52431”), which discloses a tape carrier for use with a certain semiconductor chip having its bottom or back surface cut away. Another approach is found in JP-A-5(1993)-291218, which discloses therein a technique for making both the semiconductor chip and the tape carrier thinner at the same time.
Another TCP structure is also known which includes a specific frame structure, called a “stiffener” in the semiconductor device art. The stiffener is provided around a semiconductor chip with its back surface in contact with a heat release member known as a “heat spreader.” In this TCP, a tape carrier is mounted on the stiffener for providing a junction between one end of its lead and the semiconductor chip while simultaneously providing a bump electrode at the other end of such lead. In this case the resultant TCP structure suffers from an excessive increase in thickness, which would result in an inability to achieve the desired multilayer structures.
Still another TCP structure has been found through analysis by the present inventors, which TCP structure is designed to employ a semiconductor chip that is thinner than a tape carrier having an opening called a “device hole.” The “thin” semiconductor chip is disposed in the tape carrier's device hole with its back surface being substantially at the same level as or coplanar with the bottom surface of the tape carrier. The principal surface and sidewalls of such a semiconductor chip are coated with a chosen sealing resin material. Unfortunately, this TCP structure has encountered a problem in that the semiconductor chip can warp after completion of the sealing processes due to the fact that only its principal surface and sidewalls are partly subject to sealing by use of the seal resin. To this end, this TCP structure must be designed to employ an extra hard or rigid plate for use in eliminating the occurrence of chip cracks in the back surface of the semiconductor chip. However, this does not come without an additional problem in that the resultant TCP is increased in thickness, thereby discouraging experts in the art from attempting to use such a “thick” TCP to attain a desired multilayer structure. While a structure with a seal plate provided on the seal resin is known, this also suffers from the TCP thickness increase problem, and is not suitable for use as a multilayer structure. Additionally, a thin package structure using a film substrate with its lower surface coplanar with the back surface of a chip has been disclosed, for example, in JP-A-60(1985)-106153.
According to currently available technologies recognized by the present inventors, the semiconductor chips are thinner than the tape carriers in most TCP structures. In cases where such TCPs are laminated on one another to form a multilayer structure, the outer leads are typically machined to have a so-called “gull-wing” shape for elimination of unwanted contact of a semiconductor chip with its associated mounting board, such as a printed circuit board. In addition, in case plural ones are to be mounted in the direction along the thickness of the TCP, a specific parts-mount scheme must be employed which includes the steps of pre-fabricating those TCPs with outer leads of different lengths, and, after completion of various lead machining processes, rearranging the layout in a way such that those with low mount heights are located at lower levels, whereas the remaining ones with higher mount levels are at upper levels. In this case, however, different tape carriers are used to accomplish the intended overlap mounting with outer leads different in size from one another. This in turn calls for the use of a variety of types of tape carriers as well as various molding die tools, which would result in an increase in production cost therefor. Additionally, the TCP lamination mount technique is disclosed in JP-A-64(1989)-71162, for example.
It is therefore an object of the present invention to provide a technique for enabling the manufacture of a semiconductor device with a TCP structure which is high in reliability.
Another object of this invention is to provide a technique for enabling fabrication of a thin small-size semiconductor device with TCP structures offering high-density mountability and enhanced reliability, while reducing costs.
These and other objects, features and advantages of the invention will be apparent from the following more particular description of various preferred embodiment of the invention, as illustrated in the accompanying drawings.
SUMMARY OF THE INVENTION
A semiconductor device in accordance with the present invention is specifically arranged to include a semiconductor chip disposed in a device hole provided in a tape carrier with one end of a lead on said tape carrier being electrically connected to an external terminal of said semiconductor chip, wherein said semiconductor chip is smaller in thickness than said tape carrier, and wherein said semiconductor chip is sealed by a seal resin material to allow a principal surface and a back surface of said semiconductor chip to be coated therewith. Whereby, it becomes possible to reduce any possible stress that the semiconductor chip can receive from the principal surface and rear surface thereof. Also, the semiconductor device of this invention is such that said semiconductor chip is disposed on a stress neutral plane extending parallel to the principal surface of said semiconductor chip at the position along a thickness of said tape carrier. This makes it possible to allow the semiconductor chip to be placed at a location whereat the stress receivable from the TCP is kept minimal. Even in the event any external force is applied causing the TCP to deform as a whole, the semiconductor chip may be subjected to a minimal stress. It is also possible to suppress the occurrence of warp in the overall TCP structure due to bimetal effects, which may in turn enable noticeable reduction of risks of chip cracks and/or connection failures during mounting assembly procedures of the semiconductor device.
In addition, the semiconductor device of the instant invention is such that a passage for use in seal resin injection is formed at part of said tape carrier thereby causing said device hole to be coupled to a gate of a metal mold structure used during formation of said seal resin. With such an arrangement, it is possible to successfully inject the
Miyamoto Toshio
Tsubosaki Kunihiro
Antonelli Terry Stout & Kraus LLP
Hitachi , Ltd.
Talbott David L.
Thai Luan
LandOfFree
Semiconductor device and manufacturing method thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Semiconductor device and manufacturing method thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiconductor device and manufacturing method thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3129513