JP2000099673A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact type IC card whose communication characteristics are satisfactory. SOLUTION: In this semiconductor device, the casing of a circuit module 5 constituted by mounting an IC chip 4 on a circuit board 3, in which an antenna coil 2 is pattern-formed, is operated by a board 8 constituted of an adhesive layer 6 and a cover sheet 7 so that a non-contact IC card 1, in which the antenna coil and the IC chip are embedded in the board, can be formed. Antenna pads 2a whose diameters are larger than the line width of the antenna coil are pattern-formed at the both edge parts of the antenna coil 2. For carrying out the flip chip mounting of the IC chip on the antenna pads, the joint positions of the antenna pads with pad parts 4a being the input and output terminal of the IC chip are adjusted so that the antenna pads can not be overlapped with an analog circuit part 4b of the IC chip.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device represented by a non-contact type IC card which wirelessly receives power from a reader / writer and transmits / receives signals to / from the reader / writer.

[0002]

2. Description of the Related Art A semiconductor device, such as a card type, a tag type or a coin type, on which an IC is mounted has an abundant amount of information and a high security performance. Is progressing. Among them, a non-contact type semiconductor device developed recently has a structure in which an external terminal is not provided on a base, and a power supply from a reader / writer and transmission / reception of signals between the reader / writer are performed wirelessly. In addition to the fact that the external terminals are not substantially damaged as described above, it is easy to handle such as storage and can withstand long-term use, and also has the feature that data is not easily tampered with and the security performance is more excellent. It is expected to spread to a wider field in the future.

A non-contact type semiconductor device of this type has a circuit module including an IC chip and an antenna coil for wireless communication embedded in a base body. There is known an antenna coil in which a pattern formed on a circuit board is used, and a pad portion serving as an input / output terminal of an IC chip is connected to antenna pads formed on both ends of the antenna coil.

[0004] The antenna pad is formed to be much larger than the pad portion of the IC chip in order to facilitate connection with the pad portion of the IC chip, more specifically, positioning of both. As described above, when the antenna pad is formed to be much larger than the pad portion of the IC chip, even if the setting position of the IC chip with respect to the antenna pad is slightly shifted, both can be securely connected.
The work of positioning the IC chip with respect to the antenna coil, and hence the work of connection, can be simplified.

[0005]

The circuit section of the IC chip has an analog circuit section for handling analog signals input / output via an antenna coil and a digital signal section for handling digital signals.

[0006] The inventors of the present application have conducted research on the improvement of the communication characteristics of a non-contact type IC card. , A parasitic capacitor is formed, and the effect of this changes the analog signal characteristics, deteriorating the communication characteristics.

In the above description, a semiconductor device using a circuit module formed by connecting a pad portion of an IC chip to an antenna pad patterned on a circuit board has been described as an example. In a semiconductor device provided with a circuit module in which wire coils are directly connected, similar inconvenience occurs when the analog circuit portion of the IC chip and the winding coil overlap each other in the thickness direction. Also, in a semiconductor device including a circuit module formed by connecting a pad portion of an IC chip and an antenna coil via a lead terminal, if the analog circuit portion of the IC chip and the lead terminal overlap each other in the thickness direction, Similar disadvantages arise.

The present invention has been made based on such knowledge, and an object thereof is to provide a semiconductor device such as a non-contact type IC card having good communication characteristics.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an IC chip, an antenna coil for wireless communication electrically connected to a pad portion of the IC chip, and an IC chip. In a semiconductor device having a base in which a circuit module including an antenna coil is embedded, said IC chip is provided so that an analog circuit portion of said IC chip and a conductor of another member do not overlap in a thickness direction. The arrangement of the conductor with respect to is adjusted.

When the circuit module is formed by connecting a pad portion of an IC chip to an antenna pad formed on a circuit board, all the circuit patterns including the antenna pad are analog circuits of the IC chip. Do not overlap with the department. Further, when a circuit module in which a winding coil is directly connected to a pad portion of an IC chip is used as the circuit module, the entire winding coil is prevented from overlapping the analog circuit portion of the IC chip. Further, in the case where a circuit module in which a pad portion of an IC chip and an antenna coil are connected via a lead terminal is used as the circuit module, the entire lead terminal and antenna coil overlap the analog circuit portion of the IC chip. Do not match.

As described above, when the arrangement of the conductors with respect to the IC chip is adjusted so that the analog circuit portion of the IC chip and the conductor of another member do not overlap in the thickness direction, the parasitic capacitance between the analog circuit portion and the conductor is adjusted. Since the capacitor is not formed, the analog signal characteristics are hardly deteriorated, and the communication characteristics as designed can be maintained. When the digital circuit portion of the IC chip and the conductor of another member overlap in the thickness direction, a parasitic capacitor is formed between the digital circuit portion and the conductor. Since it is hardly affected, the communication characteristics do not deteriorate.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described using a non-contact type IC card as an example.

<First Embodiment> FIGS. 1 to 5 are explanatory views of a non-contact type IC card according to a first embodiment.
1 is a partially cutaway plan view of the non-contact IC card according to the embodiment, FIG. 2 is a cross-sectional view of the non-contact IC card shown in FIG. 1, and FIG. 4 and 5 are enlarged plan views showing modified examples of the non-contact type IC card according to the first embodiment.

As can be seen from these figures, the non-contact IC card 1 of the present embodiment includes a circuit module 5 comprising an IC chip 4 mounted on a circuit board 3 on which an antenna coil 2 is formed in a pattern. 6 and a cover sheet 7 to form a casing.
The C chip 4 is embedded in the base 8.

The circuit board 3 is formed by printing a required circuit pattern including the antenna coil 2 on the surface of an insulating substrate 3a made of an insulating resin sheet such as polyethylene terephthalate (PET) or vinyl chloride (PVC). It is formed by means such as etching. As shown in FIGS. 1 and 3, antenna pads 2 a having a diameter larger than the line width of the antenna coil 2 are formed at both ends of the antenna coil 2.

As the IC chip 4, any IC chip conventionally mounted on a non-contact type IC card can be used. However, in order to reduce the thickness of the non-contact type IC card, the total thickness is 50 μm or less. It is particularly preferable to use one thinned to about 150 μm. This IC chip 4
It is flip-chip mounted on the antenna pad 2a and is electrically connected to the antenna coil 2. At this time, as shown in an enlarged manner in FIG. 3, the antenna pad 2a is connected to the analog circuit portion 4b of the IC chip 4 and the circuit board 3 and the IC chip 4.
The joining position between the antenna pad 2a and the pad portion 4a, which is the input / output terminal of the IC chip 4, is adjusted so as not to overlap each other in the thickness direction. As a result, the formation of a parasitic capacitor by the analog circuit section 4b and the antenna pad 2a can be prevented, so that the deterioration of analog signal characteristics and the deterioration of communication characteristics can be prevented.

In the example of FIG. 3, the antenna pad 2a
Is adjusted so that not only the analog circuit section 4b but also the digital circuit section 4c of the IC chip 4 does not overlap with each other. However, even if a parasitic capacitor is formed in the digital circuit section 4c, the influence on the digital signal characteristics is exerted. Is small, the antenna pad 2a and the digital circuit unit 4c can be overlapped with each other in the thickness direction of the circuit board 3 and the IC chip 4.

In the pad portion 4a of the IC chip 4,
As shown in FIG. 2, a gold bump 9 for connecting an antenna coil is provided.
Is preferably applied.

As the adhesive constituting the adhesive layer 6, any adhesive known in the art can be used as long as it has the required strength after curing. It is particularly preferable to use a thermoplastic elastomer or a mixture of a thermoplastic elastomer and a resin, since it is possible and hardly warps after curing. Further, a non-woven fabric for reinforcement can be interposed in the adhesive layer 6.

The cover sheet 7 is made of, for example, PET or PVC.
For example, an insulating resin sheet having excellent strength and printability can be used. However, in order to prevent deformation after bonding, the insulating substrate 3a is formed of the same material as the insulating resin sheet. Is particularly preferred.

In the contactless IC card 1 of this embodiment, the bonding positions of the antenna pads 2a are set so that the antenna pads 2a do not overlap with the analog circuit section 4b of the IC chip 4 in the thickness direction of the circuit board 3 and the IC chip 4. I adjusted it,
The formation of a parasitic capacitor due to the opposition between the analog circuit section 4b and the antenna pad 2a is prevented, and the deterioration of analog signal characteristics and, consequently, the communication characteristics can be prevented.

In this embodiment, the antenna pad 2a is formed to have a diameter sufficiently larger than the pad portion 4a of the IC chip 4, and the bonding position between the antenna pad 2a and the pad portion 4a is adjusted. Although the formation of the parasitic capacitor is prevented by this, instead of such a configuration, the diameter of the antenna pad 2a can be reduced as shown in FIG. 4 to thereby prevent the formation of the parasitic capacitor.

As shown in FIG. 5, an IC chip in which the analog circuit section 4b is formed at a position away from the pad section 4a can be used as the IC chip 4, thereby preventing formation of a parasitic capacitor.

<Second Embodiment> FIGS. 6 to 9 are illustrations of a non-contact type IC card according to a second embodiment.
6 is a partially cutaway plan view of the non-contact IC card according to the embodiment, FIG. 7 is a cross-sectional view of the non-contact IC card shown in FIG. 6, and FIG. 9 is a sectional view of a wire constituting the antenna coil.

As is apparent from these figures, the non-contact IC card 10 of this embodiment has a circuit board 11 on which a required circuit pattern is formed, an IC chip 4 mounted on the circuit board 11, The circuit module 5 is characterized in that the circuit module 5 is formed by an antenna coil 12 composed of a winding coil connected to a circuit board. The other parts are the same as those of the non-contact type IC card according to the first embodiment, and the description is omitted to avoid duplication.

The circuit board 11 is formed by printing or etching a required circuit pattern including a connection pattern 13 between the IC chip 4 and the antenna coil 12 on the surface of an insulating substrate 3a formed of an insulating resin sheet such as PET or PVC. And the like. The connection pattern 13
6 and 8, connection pads 13a having a diameter larger than the line width of the connection pattern 13 are formed as shown in FIGS.

The IC chip 4 is flip-chip mounted on the connection pad 13a. At this time, as shown in an enlarged manner in FIG. 8, the connection pads 13a are arranged so that the connection pads 13a do not overlap with the analog circuit portion 4b of the IC chip 4 in the thickness direction of the circuit board 11 and the IC chip 4.
a and the bonding position of the pad portion 4a of the IC chip 4 is adjusted. As a result, the formation of a parasitic capacitor by the analog circuit section 4b and the connection pad 13a can be prevented, so that the deterioration of analog signal characteristics and, consequently, the communication characteristics can be prevented. Of course, in the non-contact type IC card 10 of the present embodiment, instead of the configuration shown in FIG. 8, similarly to FIGS. 4 and 5, the diameter of the connection pad 13a is reduced to prevent formation of a parasitic capacitor. You can also
In addition, by using an IC chip in which the analog circuit section 4b is formed at a position away from the pad section 4a as the IC chip 4, the formation of a parasitic capacitor can be prevented.

As shown in FIG. 9 (a), the antenna coil 12 composed of a wound coil is formed by covering a core 12a composed of a highly conductive metal material such as copper or aluminum with an insulating layer 12b such as a resin. 9B, a bonding metal layer 12c such as gold or solder is coated around the core wire 12a, and an insulating layer is formed around the bonding metal layer 12c as shown in FIG. 9B. A wire made of a wire coated with 12b can also be used. The diameter of the wire is 20 μm to 100 μm.
The antenna coil 12 is formed by making several turns to several tens of turns in accordance with the above characteristics. The antenna coil 12 is connected to the connection pad 13a of the connection pattern 13 by means such as soldering, ultrasonic fusion, or thermocompression bonding via an anisotropic conductor.

In the non-contact type IC card 10 according to the present embodiment, the bonding positions of the connection pads 13a are not overlapped with the analog circuit portion 4b of the IC chip 4 in the thickness direction of the circuit board 11 and the IC chip 4. Since the adjustment is performed, formation of a parasitic capacitor due to the opposition between the analog circuit section 4b and the connection pad 13a is prevented, so that deterioration of analog signal characteristics and communication characteristics can be prevented.

<Third Embodiment> FIGS. 10 to 15 are explanatory views of a non-contact type IC card according to a third embodiment, and FIG. 10 shows one example of a non-contact type IC card according to the present embodiment. FIG. 11 is a non-contact I shown in FIG.
FIG. 12 is a cross-sectional view of the C card, FIG.
FIG. 13 is a cross-sectional view showing a direct connection method between the IC chip and the coil and a state of the connection portion. FIG. 14 is a cross-sectional view showing another direct connection method and the state of the connection portion of the IC chip and the coil.
FIG. 3 is a configuration diagram of a use state of a welding device applied to direct connection between an IC chip and a coil.

As is clear from FIGS. 10 to 12, the non-contact IC card 20 of this embodiment is a circuit module in which both ends of the antenna coil 12 composed of a winding coil are directly connected to the pad 4a of the IC chip 4. 5 is provided. The other parts are the same as those of the non-contact type IC card according to the first embodiment, and the description is omitted to avoid duplication.

As the antenna coil 12, the same coil as that applied to the second embodiment (see FIG. 9) can be used.

As a direct connection method between the IC chip 4 and the antenna coil 12, wedge bonding, soldering or welding is particularly preferable.

When wedge bonding the IC chip 4 and the antenna coil 12, as shown in FIG. 13 (a), an IC chip 4 in which a gold bump 9 is previously formed on a pad portion 4a is used. In this case, as the antenna coil 12, a coil having no bonding metal layer 12 c may be used, but a coil in which a gold layer is coated around the core wire 12 a is used to make bonding easier and more reliable. Is particularly preferred. As shown in the figure, the wedge bonding between the pad portion 4a and the antenna coil 12 is performed by overlapping the end portion of the antenna coil 4 on the pad portion 4a and the bonding tool 5 from the antenna coil 12 side.
1 is pressed to apply ultrasonic waves, and the energy is used to carbonize the insulating layer 12b and melt the gold bumps 9. Thereby, as shown in FIG. 13B, the pad portion 4a of the IC chip 4 and the antenna coil 1
2 is directly connected.

When the IC chip 4 and the antenna coil 12 are soldered, as shown in FIG.
As the C chip 4, a chip in which a solder bump 9b is previously formed on a pad portion 4a by solder plating is used.
In this case, as the antenna coil 12, a coil having no joining metal layer 12c can be used. However, in order to improve the wettability to the solder and to make soldering easier and more reliable, a metal around the core 12a is used. It is particularly preferable to use one coated with the like. As shown in the drawing, the soldering between the pad portion 4a and the antenna coil 12 is performed by overlapping the end portion of the antenna coil 12 on the pad portion 4a and pressing the bonding tool 52 heated to a predetermined temperature from the antenna coil 12 side. This is done by carbonizing the insulating layer 12b by the energy and dissolving the solder bumps 9b. Thus, as shown in FIG. 14B, the pad portion 4a of the IC chip 4 and the antenna coil 12 are soldered via the solder 9c. In addition,
Instead of forming the solder bumps 9 b on the pad portions 4 a of the IC chip 4,
It is also possible to use a material in which a solder layer is coated around a, and solder it in the same manner as described above. Further, a solder bump 9b may be formed on the pad portion 4a of the IC chip 4 and the antenna coil 12 may be formed by coating a core layer 12a with a solder layer.

Further, the IC chip 4 and the antenna coil 1
In the case of welding the second and the second, an IC chip in which a gold bump is formed on the pad portion 4a, an antenna coil made of a wire in which a gold layer is coated around the core wire 12a, or both of them are used. As a welding machine, as shown in FIG. 15, a welding head 62 having two electrodes 61a and 61b arranged in parallel with a small gap d therebetween, and a ribbon winding reel 63a attached to the welding head 62 ,
63b, and a ribbon-shaped resistance heating element 64 wound around these ribbon winding reels 63a, 63b, a part of which is wired so as to come into contact with the tips of the electrodes 61a, 61b.
And a motor provided with a motor 65 for driving the driving reel 63a. The ribbon-shaped resistance heating element 64
Molybdenum ribbons made of high-purity single-crystal molybdenum are most suitable because they have high specific resistance and high thermal conductivity, so that high temperatures can be locally generated and the strength is excellent. is there.

At the time of welding, as shown in FIG.
The end of the antenna coil 12 is directly superimposed on the pad portion 4a of the C chip 4, and the welding head 62 is pressed from the antenna coil 12 side. Then, the electrodes 61a, 6
A pulse power is supplied to 1b to carbonize the insulating layer 12b by utilizing the resistance heating of the ribbon-shaped resistance heating element 64 and to melt the gold bump or the gold layer coated around the core wire 12a or both. The motor 65 drives the driving reel 63 a as necessary, and brings the clean ribbon-shaped resistance heating element 64 into contact with the welding head 62 at all times. If a brush 66 for removing carbide is attached to the ribbon-shaped resistance heating element 64, the ribbon-shaped resistance heating element 64 can be used repeatedly, and the running cost can be reduced.

The welding machine shown in FIG. 15 can be used as a heat source for soldering instead of the bonding tool 52 shown in FIG.

When the end of the antenna coil 12 is directly connected to the pad 4a of the IC chip 4 in such a manner,
As shown in FIG. 12, the analog circuit unit 4 of the IC chip 4
The set positions of b and the antenna coil 12 are adjusted so that they do not overlap each other.

In the non-contact type IC card 20 of this embodiment, the set positions of the analog circuit portion 4b of the IC chip 4 and the antenna coil 12 are adjusted so that they do not overlap each other. The formation of a parasitic capacitor due to the opposition to the capacitor 12 can be prevented, and the deterioration of analog signal characteristics and the deterioration of communication characteristics can be prevented.

<Fourth Embodiment> FIGS. 16 to 18 are explanatory views of a non-contact type IC card according to a fourth embodiment, and FIG. 16 shows one example of a non-contact type IC card according to the fourth embodiment. FIG. 17 is a plan view showing the non-contact I shown in FIG.
FIG. 18 is a cross-sectional view of a C card, and FIG. 18 is an enlarged plan view of a main part showing a connecting portion between an IC chip and a lead terminal.

As is apparent from these figures, the non-contact IC card 30 of this embodiment has a circuit in which the pad portion 4a of the IC chip 4 and the antenna coil 12 composed of a winding coil are connected via the lead terminal 31. A module 5 is provided. The other parts are the same as those of the non-contact type IC card according to the first embodiment, and the description is omitted to avoid duplication.

In the IC chip 4 applied to the non-contact type IC card 30 of this embodiment, the lead terminals 31 are connected to the pad portions 4a via the gold bumps 9 and the peripheral portion including the connection portions of the lead terminals 31 is formed. The resin is molded by the mold resin 32. The lead terminal 31 may be formed from a lead frame made of a conductive metal material, or may be formed from a wiring tab provided with a conductive pattern on an insulating resin substrate.

The connection between the gold bump 9 and the lead terminal 31 is as follows.
The connection is performed by solder connection, welding, conductive paste connection, or ultrasonic fusion welding.
1 is connected to the analog circuit section 4b of the IC chip 4 as shown in the enlarged view of FIG.
The bonding position between the pad portion 4a of the IC chip 4 and the lead terminal 31 is adjusted so that the chip 4 and the lead terminal 31 do not overlap each other in the thickness direction. As a result, the formation of a floating capacitor by the analog circuit section 4b and the lead terminal 31 can be prevented, so that the deterioration of analog signal characteristics and the deterioration of communication characteristics can be prevented.

The antenna coil 12 is connected to the tip of the lead terminal 31 projecting from the molding resin 32. As a method for connecting the antenna coil 12 and the lead terminal 31, any one of solder connection, welding, conductive paste connection, and crimp connection can be applied.

Also in the non-contact type IC card of this embodiment, when the IC chip 4 is connected to the lead terminal 31, the joining position of the two is adjusted so that the lead terminal 31 does not overlap the analog circuit portion 4b of the IC chip 4. So analog circuit part 4
The formation of a parasitic capacitor by b and the lead terminal 31 is prevented, so that the deterioration of the analog signal characteristics and the deterioration of the communication characteristics can be prevented.

In each of the above embodiments, a non-contact type IC card has been described as an example. However, a semiconductor device other than a card type, for example, a tag type or coin type semiconductor device may be implemented in the same manner. Can be.

[0048]

As described above, according to the present invention,
A parasitic capacitor is formed between the analog circuit part and the conductor because the arrangement of the conductor with respect to the IC chip is adjusted so that the analog circuit part of the IC chip and the conductor of another member do not overlap in the thickness direction. And a semiconductor device having excellent communication characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view of a non-contact IC card according to a first embodiment.

FIG. 2 is a cross-sectional view of the non-contact IC card according to the first embodiment.

FIG. 3 is an enlarged plan view of a portion A in FIG. 1;

FIG. 4 is an enlarged plan view of a non-contact type IC card according to a modification.

FIG. 5 is an enlarged plan view of a non-contact type IC card according to a modification.

FIG. 6 is a partially cutaway plan view of a non-contact IC card according to a second embodiment.

FIG. 7 is a sectional view of a non-contact IC card according to a second embodiment.

FIG. 8 is an enlarged plan view of a portion B in FIG. 6;

FIG. 9 is a sectional view of a wire constituting the antenna coil.

FIG. 10 is a partially cutaway plan view of a non-contact IC card according to a third embodiment.

FIG. 11 is a sectional view of a non-contact IC card according to a third embodiment.

FIG. 12 is an enlarged plan view of a portion C in FIG. 10;

FIG. 13 is a cross-sectional view showing a direct connection method between the IC chip and the antenna coil and a state of a connection portion.

FIG. 14 is a cross-sectional view showing another direct connection method of the IC chip and the antenna coil and a state of the connection portion.

FIG. 15 is a configuration diagram of a use state of a welding device applied to a direct connection between an IC chip and an antenna coil.

FIG. 16 is a partially cutaway plan view of a non-contact IC card according to a fourth embodiment.

FIG. 17 is a sectional view of a non-contact IC card according to a fourth embodiment.

FIG. 18 is an enlarged plan view of a main part showing a connection part between an IC chip and a lead terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Non-contact IC card 2 Antenna coil 2a Antenna pad 3 Circuit board 3a Insulating board 4 IC chip 4a Pad part (gold bump) 4b Analog circuit part 4c Digital circuit part 5 Circuit module 6 Adhesive layer 7 Cover sheet 8 Base 10 Non-contact IC card 11 Circuit board 12 Antenna coil 13 Connection pattern 13a Connection pad 20 Non-contact IC card 30 Non-contact IC card 31 Lead terminal 32 Mold resin

Claims (4)

[Claims] An IC chip, an antenna coil for wireless communication electrically connected to a pad portion of the IC chip, and a base for burying a circuit module including the IC chip and the antenna coil. The semiconductor device according to claim 1, wherein an arrangement of the conductor with respect to the IC chip is adjusted such that an analog circuit portion of the IC chip and a conductor of another member do not overlap in a thickness direction. 2. The semiconductor device according to claim 1, wherein
The semiconductor device according to claim 1, wherein the conductor is a circuit pattern including the antenna coil patterned on a circuit board. 3. The semiconductor device according to claim 1, wherein
The semiconductor device, wherein the conductor is a winding coil serving as the antenna coil. 4. The semiconductor device according to claim 1, wherein
The semiconductor device according to claim 1, wherein the conductor is a lead terminal for connecting the pad portion and an antenna coil.