JPS63107594A - Card-shaped electronic device - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a semiconductor device, and particularly to a card-shaped semiconductor device mounted on a flexible substrate such as a card (hereinafter referred to as an IC card) having a built-in semiconductor device. It relates to techniques that are effective when applied to

[Prior art]

Conventionally, IC cards have a thin plate shape in which a semiconductor chip is protected by being sandwiched between plastic protective plates and can be carried freely in a pocket or card case. Since the IC card is carried around in this way, the bending stress applied to the IC card is large.

[Problem that the invention seeks to solve]

However, as a result of studying this technology, one inventor found the following problems.

In conventional IC cards, the IC chip material is silicone, so it has less brittleness due to bending than plastic.
It is very weak and may break easily. In particular, as the functionality of semiconductor integrated circuits increases, the degree of integration increases, and the semiconductor chip size increases, the bending stress σ2 becomes larger than the bending stress σ, as shown in Figure 6, and the stress on the semiconductor chip increases, causing cracks. It becomes easier.

An object of the present invention is to provide a technique that can prevent damage to a semiconductor chip due to bending stress in a semiconductor device mounted on a flexible substrate such as an IC card.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

A brief overview of typical inventions disclosed in this application is as follows.

In a card-shaped semiconductor device mounted on a flexible protection plate, a semiconductor chip is divided into a plurality of parts with at least one function as a unit, and these parts are electrically connected with flexible lead wires.

[Effect]

According to the above means, the semiconductor chip is divided into a plurality of parts with at least one function as a unit, and each divided chip is electrically connected with a flexible lead wire, whereby the semiconductor chip is divided into small chips. Since the bending stress is reduced, damage to the semiconductor chip due to the bending stress can be prevented.

[Embodiments of the invention]

An embodiment of the present invention will be specifically described below with reference to the drawings.

Note that throughout the description of the embodiments, parts having the same functions are given the same reference numerals, and repeated explanations thereof will be omitted.

FIG. 1 is a partially cutaway perspective view showing an embodiment of a card-shaped semiconductor device of the present invention.

FIG. 2 is a cross-sectional view when the wiring on the flexible substrate 2 shown in FIG. 1 and the semiconductor chip are connected by a flip-chip method.

FIG. 3 is a cross-sectional view when the wiring on the flexible substrate 2 shown in FIG. 1 and the semiconductor chip are connected by another method.

As shown in FIG. 1, the card-shaped semiconductor device of this embodiment is constructed by dividing a semiconductor integrated circuit (IC, VLSI) chip into a plurality of parts with at least one function as a unit, and wiring the divided chips 1. on the flexible substrate 2,
Die bonding is performed, and the chips 1 are connected by flexible lead wires 3 (for example, copper: Cu, copper plated with nickel), and mounted on a card 4.

Regarding the connection method between the respective chips 1, as shown in FIG. 2, the chips 1 are electrically connected to the wired flexible substrate 7 using protruding electrodes 8 of a flip-chip type.

Another embodiment of the electrical connection method between the chips 1 is shown in FIG. 3.

As shown in FIG. 3, each chip 1 is die-bonded onto a flexible sheet and electrically connected using flexible lead wires 9 and protruding electrodes 10.

The semiconductor integrated circuit (IC, VLS I) chip 1 is 1
For example, as shown in FIG. 4 (block diagram), a processing unit (CPU) 11 is provided in the center, and a ROM (Re
ad 0nly Mamory) 12 and RAM (R
andom Access Memory) 13 is provided. These peripheral parts include an input/output (Ilo) port 14, a clock generator 15 . Standby circuit 16° Interrupt circuit 17. Timer 18. Serial interface 19. Analog to digital converter (A/D
)20. Digital to analog converter (D/A)
21. LCD driver 22. Data latch circuit 23.
A DMA controller 24 and the like are provided.

This embodiment deals with such a semiconductor integrated circuit (IC).

VLS I) Chip 1 is divided into a plurality of parts with at least one function as a unit. For example, if the chip is divided into a chip having one function, it is divided into 14 parts.

Further, a multiprocessor type semiconductor chip includes, for example, a microprocessor 31. Memory management circuit 32° disk controller 33. Local Area Network Controller 34. General-purpose input/output port M (I/○) 35. System interface 36, coprocessor 37. DMA controller 38, synchronous and asynchronous data communication circuit 8
9, etc., which are electrically connected by a data bus 40. Such a multiprocessor type semiconductor chip is divided into a plurality of parts with at least the one function as a unit.

By dividing the semiconductor chip into a plurality of parts with at least one function as a unit and electrically connecting each divided chip 1 with flexible lead wires 3 and 9, the semiconductor chip is divided into small chips. Since the bending stress becomes small, damage to the semiconductor chip due to the bending stress can be prevented.

The present invention has been specifically described above based on examples, but 1.
It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof.

For example, the number of divisions of the semiconductor chip is ideally such that it can withstand the bending force up to the bending limit of the protective plastic.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

In a card-shaped semiconductor device mounted on a flexible protection plate, the semiconductor chip is divided into multiple parts with at least one function as a unit, and each divided chip is electrically connected with a flexible lead wire. is divided into smaller chips, and the bending stress is reduced.

Damage to the semiconductor chip due to bending stress can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing an embodiment of the card-shaped semiconductor device of the present invention, and FIG. 2 is a flip-chip method for connecting the wiring on the flexible substrate 2 shown in FIG. 1 to the semiconductor chip. FIG. 3 is a cross-sectional view when the wiring on the flexible substrate 2 shown in FIG. 1 and the semiconductor chip are connected by another method. Figure 4 is a diagram for explaining a method for dividing a single-chip microcontroller type semiconductor chip, Figure 5 is a diagram for explaining a method for dividing a multiprocessor type semiconductor chip, and Figure 6 is a diagram for explaining a method for dividing a semiconductor chip for a multiprocessor type. FIG. 2 is a diagram for explaining problems with the IC card. In the figure, 1... Divided chip, 2, 7... Flexible board, 3, 9... Lead wire, 4... Card,
8°10...This is a protruding electrode. l' λ Agent Patent Attorney Masaru Koyo (Male゛'

Claims (4)

[Claims] 1. A card-shaped semiconductor device mounted on a flexible protection plate, characterized in that a semiconductor chip is divided into a plurality of parts with at least one function as a unit, and the parts are electrically connected by flexible lead wires. . 2. 2. The card-shaped semiconductor device according to claim 1, wherein the semiconductor chip is of a single-chip microcomputer type. 3. 2. The card-shaped semiconductor device according to claim 1, wherein the semiconductor chip is of a multiprocessor type. 4. The card-shaped semiconductor device according to claim 1, wherein the semiconductor device is an IC card.