JPH0236552A - Integrated circuit device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an integrated circuit device used in IC cards and the like.

2. Description of the Related Art In recent years, so-called IC cards, in which integrated circuit elements such as microcomputers and memories are mounted or embedded in plastic cards, have been put into practical use.

This IC card has a larger storage capacity and better security than the magnetic stripe cards that are already widely used, so it can be used for a variety of purposes such as identification cards, rather than the traditional magnetic stripe cards. It is considered to be used for this purpose.

IC cards are plastic cards made of vinyl chloride, etc.
It has a configuration in which an integrated circuit device having a terminal for connection with an external device such as a reader/writer is mounted, and this integrated circuit device needs to be made extremely thin. For this reason, the conventional integrated circuit device is a thin wiring board in which wiring conductors such as an external connection terminal pattern 322, a circuit pattern 33, and a through hole 34 are formed on an insulating substrate 31 on a film, as shown in cross section in FIG. Next, the integrated circuit element 36 is die-bonded, and the input/output electrodes of the integrated circuit element 36 and the circuit pattern 33 are connected with metal wires 36 by wire bonding or the like. Further, a sealing frame 37 for preventing resin leakage during resin sealing is provided by adhering to the wiring board, and the wiring board is sealed with a sealing resin 38 such as epoxy resin. (Japanese Unexamined Patent Publications No. 55-56647, No. 58-92597) Problems to be Solved by the Invention The integrated circuit devices mounted on IC cards are thinner, have high reliability, and have high dimensional accuracy. , there is a need for even lower costs. However, the above-described integrated circuit device has the following problems. (1) The wiring board is expensive. (2) Since the through-holes 34 are formed by plating, variations in the plating thickness during the formation of the through-holes result in variations in the total thickness of the wiring board, making it difficult to obtain good thickness accuracy. (3) When the integrated circuit element 36 is sealed with resin, the sealing resin 38 is inserted into the through hole 34.
Therefore, a means for sealing the through hole 34 is required to prevent leakage.

On the other hand, a lead frame processed into a desired shape is used, one side of which is used as an external connection terminal, and the other side used as a connection surface for mounting an integrated circuit element, and the part of the lead frame other than the external connection terminal is sealed with the integrated circuit element. Integrated circuit devices covered with adhesive resin do not require the above-mentioned high-precision precision wiring boards, so they can be manufactured with high dimensional accuracy and high efficiency, and have the advantage of being inexpensive. There are limitations and many manufacturing difficulties remain. For example, the thickness of an IC card is 76 mm according to the 15O (International Organization for Standardization) standard.
0 ± 80 μm, and the unevenness on the surface of the C card caused by mounting an integrated circuit device must be kept small from the viewpoint of the card's mechanical strength and prevention of misreading of the magnetic stripe. If the deflection is large, it becomes difficult to satisfy the above-mentioned dimensions when mounted on a card, and the integrated circuit element may be damaged due to the stress caused by the deflection.

The present invention is intended to solve these problems, and aims to construct an integrated circuit device using a lead frame, and to suppress the deflection thereof to a certain value or less.

Means for Solving the Problems In order to solve this problem, the present invention provides an mI lead frame in which at least a part of one side of the lead frame is used as a terminal for external connection, and an integrated circuit element is mounted and connected to the other side. The integrated circuit element on the other side of the lead frame is covered with at least a sealing resin, and the difference in coefficient of linear expansion between the sealing resin and the lead frame is set to 7X 1o-6/'c or less.

Due to the above-described structure, the present invention does not require the high-density precision circuit board used in the past, allows the use of a general lead frame that is inexpensive and hidden, and can be easily manufactured to a thickness as an integrated circuit device. At the same time, it becomes possible to suppress the deflection below a certain value.

Embodiment Hereinafter, an integrated circuit device according to an embodiment of the present invention will be described with reference to the drawings. , FIG. 1 shows a cross section of an integrated circuit device configured in an embodiment of the present invention.

As shown in FIG. 1, in this embodiment, a lead frame 40 is formed from a band-shaped metallic material into a predetermined shape by photo-etching or the like, and is plated with gold or the like, and one side is provided with an external connection terminal 402L. Then, the integrated circuit element 5o is die-bonded to the other part 40b, and the other part 40 is bonded to the other part 40 by wire bonding 6o made of material such as gold, aluminum, copper, etc.
b and the connection pad portion of the integrated circuit element 6o are connected. This part can also be implemented with wireless face bonding or with a tape carrier. After making the necessary connections between the integrated circuit element 50 and the lead frame 40, the integrated circuit element 5o is covered with a sealing resin 70 by a transfer molding method using a molding material such as epoxy.
Protect. As a result, an integrated circuit device 100 is obtained.

This transfer molding method will be explained in more detail. First, the lead frame 4o on which the integrated circuit element 60 is mounted is set in a mold of a transfer molding machine set at a temperature of 170 to 180'C, and then heated to a temperature of 70 to 90'C.
The preheated Epokin molding resin is inserted into the transfer chamber, and is injected into the pre-sealed cavity under heat and pressure to harden. The molding conditions at this time are molding temperature = 170 to 180'C, molding pressure 3 o to 1ookq/cri, and molding time = 40 to 120 SeC.

Regarding the integrated circuit device 100 configured as above,
Deflection when the lead frame material and the sealing resin material are variously changed will be explained below.

Table 1 shows the linear expansion coefficients of the lead frame material and sealing resin material used in this example.

Table 1: Linear expansion coefficients of lead frame materials and sealing resin materials (Table 2) is the deflection at the external connection terminal surface of integrated circuit devices fabricated by various combinations of lead frame materials and sealing resin materials. . However, the thickness of the lead frame is 150
The thickness of the sealing resin layer is 4BOfim, and the deflection is the value at 12.6 diagonals of the integrated circuit device.

<Table 2> Deflection of the integrated circuit device in each combination FIG. 2 is a graph showing the relationship between the difference in linear expansion coefficient and the deflection. From the figure, it can be seen that the smaller the difference in linear expansion coefficients between the combinations, the smaller the deflection of the integrated circuit device.

Next, the relationship between deflection and mechanical strength of an integrated circuit device will be shown. Table 3 shows the results of repeated roller passing tests with integrated circuit devices mounted on cards.

<Table 3> Roller passing test results From the above, it can be seen that in order to withstand the roller passing test of 2okqf', the deflection must be suppressed to 50 μm or less. From FIG. 2, in order to keep the deflection of the integrated circuit device to 50 μm or less, the difference in linear expansion coefficient between the lead frame 4o and the sealing resin To must be 7×10/”C or less.

As described above, according to this embodiment, by combining the lead frame 40 and the sealing resin 700 so that the difference in linear expansion coefficient is 7×10-6/°C or less, the deflection of the integrated circuit can be reduced to 50 μm or less. dimensional accuracy and mechanical strength can be improved.

Effects of the Invention As described above, in the present invention, at least a part of one side of a lead frame is used as an external connection terminal, an integrated circuit element is mounted and connected on the other side, and the other side of the lead frame is connected to the external connection terminal. In a structure in which an integrated circuit element is covered with at least a sealing resin, high efficiency can be achieved by combining the sealing resin and the frame so that the difference in linear expansion coefficient is 7×10-6/°C or less. It does not require a high-precision precision circuit board and can use an inexpensive and extremely common lead frame.Moreover, it reduces the deflection that occurs during manufacturing and improves dimensional accuracy and mechanical strength, making it suitable for use as an integrated circuit device for mounting IC cards. Practicality and reliability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an integrated circuit device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the results of an investigation on the relationship between the deflection of the integrated circuit device and the difference in linear expansion coefficient, and FIG. 1 is a cross-sectional view of an integrated circuit device. 4o...Lead frame, 40a...
One side of the lead frame, 40b... The other side of the lead frame, 6o... Integrated circuit element,
60...Wire bonding, 70...
- Sealing resin, 1oO...Integrated circuit device. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (1)

[Claims] At least a part of one side of the lead frame is used as an external connection terminal, an integrated circuit element is mounted and connected on the other side, the integrated circuit element on the other side of the lead frame is covered with at least a sealing resin, and the above-mentioned sealing is performed. An integrated circuit device in which the difference in coefficient of linear expansion between the adhesive resin and the lead frame is 7×10^-^6/°C or less.