FR2787610A1 - INTEGRATED CIRCUIT BOARD CAPABLE OF PREVENTING A SEMICONDUCTOR CHIP MOUNTED ON IT TO FRACTURE - Google Patents

Abstract

Integrated circuit board, which can withstand a load which is applied to it in the form of bending or pressure application at a point and helps to prevent a semiconductor chip from fracturing. The IC card (1) has a three-layer structure including a circuit sheet (2), an intermediate sheet (3), and a cover sheet (4). On a first surface of the circuit sheet, a circuit pattern (5) and a semiconductor chip (6) are arranged, the semiconductor chip is molded with a gasket member (7), and a backing plate (10 ) made of a stainless plate is arranged just above the sealing element. When the backing plate has a Young's modulus of 100 to 300 GPa and the total thickness of the IC board is within 400 to 900 µm, the thickness t of the backing plate is selected to satisfy one of the following equations (1), (2).t > (1.04 x 10-6 )T4 - (5.26 x 10-4 ) T3 + (1.02 x 10-1 )T2 - 9.12T + 3.55 x 102 --(1) t > (7.22 x 10-7 )T4 - (4.0 x 10-4 ) T3 + (8.08 x 10-1 )T2 - 7.61T + 3.3 x 102 --(2) Here, T represents the thickness of the semiconductor chip.

Description

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  CARD WITH INTEGRATED CIRCUIT CAPABLE OF PREVENTING A CHIP OF

  SEMICONDUCTOR MOUNTED ON IT TO FRACTURE

Description

  This invention relates to an integrated circuit card (IC), and in particular to an integrated circuit card comprising a semiconductor chip having a CPU function etc ..., and in particular to an integrated circuit card capable of to prevent a semiconductor chip from fracturing during a

actual use.

  As a conventional card, a magnetic-type card such as a credit card, a credit card and the like is widely used. This type of card is made by spreading a magnetic strip on a plastic card so that the information recorded on it is read. In this kind of magnetic recording type card, there was a problem that the information can easily be deciphered by a third party, and that the ability to record

  information is relatively weak.

  Thus, recently, an IC card in which a semiconductor chip having a memory function, a CPU function or the like is mounted on a card-type substrate has been developed, and is already practiced. In general, this type of integrated circuit card comprises a three-layer structure comprising a circuit sheet on which the semiconductor chip having a circuit pattern is mounted, an intermediate sheet having a recess for containing the semiconductor chip and mounted on the circuit sheet, and a cover sheet intended for

  cover the intermediate sheet.

  In this case, the integrated circuit card having the structure described above is relatively fragile vis-à-vis

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  a bending force applied to the semiconductor chip, and may be disabled due to a fracture of the semiconductor chip. To solve this problem and to improve the anti-bending characteristic of the semiconductor chip, some countermeasures are proposed in the

  JP A 9-156265, JP A 9-263 082, for example.

  An integrated circuit card described in JP A 9-

  156,265 is manufactured by the following steps. That is, a semiconductor chip is mounted on a circuit substrate and a spacer having a recess for containing the semiconductor chip is adhered to the circuit substrate. In addition, a stainless plate as a reinforcing plate having a thickness of approximately 30 μm and formed slightly larger than the hollow, is arranged just above the semiconductor chip. After that, a cover film is glued to the stainless plate. In contrast, an IC card disclosed in JP A 9-263,082 is manufactured by gluing a stainless plate as a backing plate having a thickness of approximately 20 μm on at least one side surface of the chip chip. semiconductor. After that, the semiconductor chip is changed to a sheet-like interlayer, and sheets are glued on both the main surface and the surface.

back of the inter-layer.

  In this case, various types of charges are applied to the integrated circuit card during its actual use. In general, the load is classified into two types, i.e. a bending load for which the IC card curves in a circular arc or is veiled, and a pressure load at a point where a Pressure force is applied locally to the IC card. With this type of load, since the hardness of the semiconductor chip is substantially improved by arranging a reinforcing plate on at least one surface of the semiconductor chip, it can

  prevent the semiconductor chip from fracturing.

  However, according to an experimental result, it turns out that the conventional reinforcement method for the semiconductor chip in which the reinforcing plate is arranged on a surface of the semiconductor chip, can not always prevent the semiconductor chip from fracture. That is to say

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  that a constraint generated in the semiconductor chip may be increased compared to that without the backing plate, when the load is applied to the integrated circuit board by bending or pressing on a point, depending on the relationship between the thickness of the reinforcement plate and

  the thickness of the semiconductor chip.

  This invention has been conceived in view of the background described so far and its first object is to provide an integrated circuit card, which makes it possible to support a load applied to it in the form of a flexion or pressure on a point and prevents a semiconductor chip from fracturing. In accordance with the present invention, an integrated circuit card comprising: a circuit substrate having a conductive circuit, a semiconductor chip mounted on the circuit substrate, a reinforcing plate laminated on the semiconductor chip, for reinforcing the chip of semiconductor, and a laminated cover sheet on the

  reinforcement plate, to protect the semiconductor chip.

  In this case, when the thickness of the semiconductor chip is T, the thickness t of the reinforcing plate is in a range

  satisfying at least one of the following equations (1) and (2).

  t> (1.04 x 10-6) T4 - (5.26 x 10-4) T3 + (1.02 x 10-1) T2 - 9.12 T + 3.55 x 102 --- (1) t> (7.22 x 10-7) T4 - (4.0 x 10-4) T3 + (8, 08 x 10-1) T2 - 7.61T + 3.3 x 102 --- (2) In accordance with the present invention, since the thickness t of the backing plate is chosen to satisfy one of equations (1) and (2), it can prevent the semiconductor chip from fracturing even if one following cases (A), (B) is caused. In addition, when the thickness t of the reinforcing plate is chosen so as to satisfy equation (2), it can prevent the semiconductor chip from fracturing even if one of the cases (A), (B) or the following case (C)

is provoked.

  (A) a first case in which the user sits on a chair, the integrated circuit card being in the trouser revolver pocket, (B) a second case in which the integrated circuit card is pressed by a relatively sharp protuberance such as

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  tip of a ballpoint pen, that is, a pressing force is applied to a very narrow point of the IC card, (C) a third case in which the IC card in a handbag or the like is pressed by a button or the like of the handbag or clothing, that is, a pressing force is applied to a relatively wide point of the

integrated circuit card.

  These and other objects, configurations and features of the present invention will be appreciated from a study of

  the following detailed description of the appended claims

  and drawings, all of which form part of this application. In the drawings, like parts or corresponding parts are given the same numerical references

  each other to eliminate a redundant explanation.

  In the drawings: Fig. 1 is a simplified sectional view of an integrated circuit board of a preferred embodiment according to the present invention; Fig. 2 is a perspective view of the integrated circuit board before FIG. 3 is a graph illustrating an examination by application of pressure on a narrow point. FIG. 5 is a graph illustrating an examination by application of pressure on an obtuse point. FIG. Figs. 6A and 6B are graphs illustrating the experimental results of the flexural examination. Figs. 7A and 7B are graphs illustrating the experimental results of the narrow point pressure application. Figs. 8A and 8B are graphs illustrating the experimental results of the examination by application of pressure on an obtuse point, FIG. 9 is a graph illustrating a first curve intended to calculate an equation of one thickness of a reinforcing plate, and Figure 10 is a graph illustrating a second curve for calculating an equation of the thickness of the plate

reinforcement.

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  [First Embodiment] A preferred embodiment of the present invention will be

  explained below with reference to the accompanying drawings.

  Firstly, as shown in FIGS. 1 and 2, an integrated circuit card 1 consists of a circuit sheet 2 as a circuit substrate, an intermediate sheet 3 and an intermediate bonding layer. , so

than a cover sheet 4.

  The circuit sheet 2 is formed of a sheet made of plastic material such as a polyester-based plastic material, specifically PET (polyethylene terephthalate). A circuit pattern 5 having a wound shape as a conductive circuit is formed on a surface of the circuit sheet 2, and also a semiconductor chip 6 connected to the circuit pattern 5 is mounted on a surface of the circuit sheet. 2. The semiconductor chip 6 is molded by a seal member 7, which is made of a relatively hard material such as an epoxy plastic material. The seal member 7, the intermediate sheet 3, and the cover sheet 4 define a housing 8 for protecting the chip from

semiconductor 6.

  In this embodiment, the circuit pattern 5 having the wrapped shape is formed by screen printing means using a conductive paste such as a polyester-based silver paste (Ag), and the semiconductor chip 6 is mounted by an anisotropic conductive bonding 9, for example using a chip chip method. The circuit pattern 5 functions as an element for signal communication (transmit / receive) with an external device and also acts as an antenna for transmitting / receiving radio signals. In this embodiment, the energy to implement the CPU and other formed on the semiconductor chip 6 is provided by the radio signal from the

  external device received by the circuit pattern 5.

  Intermediate sheet 3 is made of a hot-melt type plastic that melt in the molten state when heated, such as a polyester-based fuse adhesive. The intermediate sheet 3 not only protects the circuit pattern 5, the semiconductor chip 6, etc., but also adheres the intermediate sheet 3 itself to the

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  circuit sheet 2 and the cover sheet 4 so as to cover the circuit pattern 5, the semiconductor chip 6 and other without interstices. In addition, the cover sheet 4 serves to protect the intermediate sheet 3, which is relatively soft, and the cover sheet 4 is made of a sheet of polyethylene terephthalate as the sheet of

circuit 2, for example.

  In order to manufacture this integrated circuit card having a three layer structure, the semiconductor chip 6 is mounted on the circuit board 2, and then the semiconductor chip 6 is covered with the epoxy plastic material to form As the epoxy-based plastics material is liquid at room temperature before being cured, it can cover a surrounding portion of the semiconductor chip 6 without

  interstices because of its liquid state.

  After molding the semiconductor chip 6 with the seal member 7, the intermediate sheet 3 and the cover sheet 4 are laminated thereon in that order. After that, a laminated structure is glued by thermocompression

  using a thermal press device not shown.

  As a result, since the fuse adhesive constituting the intermediate sheet 3 is melted by being heated so as to have a liquid state, the molten fusible adhesive covers the circuit pattern 5 and the joint member 7 without interstices. At the same time, the intermediate sheet 3 is compressed to have a uniform thickness by being pressed both from the upper and lower sides, and adheres to the circuit sheet 2 and the cover sheet 4. After

  this, the fire - the intermediate 3 is hardened by cooling.

  As a result of these steps, the integrated circuit card 1 having the three-layer structure comprising the circuit sheet 2, the intermediate sheet 3 and the

cover 4, is formed.

  In the integrated circuit card 1 described above, as the circuit sheet 2 and the cover sheet 4 are made of PET, and the intermediate sheet 3 is made of a polyester-based fuse adhesive, both having elasticity, the integrated circuit card 1 bends flexibly with elasticity when a bending force is applied thereto. When the IC card is bent, the semiconductor chip 6 may fracture due to the bending force applied to the semiconductor chip 6. As a result, the backing plate 10 is provided to substantially improve the hardness by strengthening the semiconductor chip 6. The reinforcing plate 10 is formed of substantially the same size as the seal member 7, and is arranged on the seal member 7 by superimposing it on the semiconductor chip 6 after it has been sealed. by the seal member 7. In this case, the reinforcing plate 10 is positioned so that the center of the reinforcing plate 10 substantially matches that of the semiconductor chip 6. After that, like the 2, the intermediate sheet 3 and the cover sheet 4 are bonded by thermocompression as described above, the reinforcing plate 10 is covered with the fuse adhesive without gaps by the fuse adhesive constituting the

  intermediate sheet 3 which is melted.

  Here, an upper surface of the semiconductor chip 6 (see FIG. 1) is formed into a mirror surface 6a. That is, an integrated circuit is formed on a lower surface 6b of the semiconductor chip 6 (the side of the circuit sheet 2), and the upper surface 6a has a mirror surface which is ground by a backside grinding while the semiconductor chip is still in the wafer state. As a result, the upper surface of the semiconductor chip 6 will be referred to as the mirror surface and the surface

  lower will be called circuit surface, hereinafter.

  The backing plate 10 is made of a material whose Young's modulus is within a range of 100 to 300 GPa (gigapascal) such as a stainless steel plate. In general, the thicker the reinforcing plate 10 is,

  best is the reinforcing effect of the reinforcement plate 10.

  However, during a state of charge such as bending or applying pressure at a point usually caused and in actual use, the stress applied to the semiconductor chip 6 may be undesirably increased depending on the relationship to the thickness of the the chip of

  semiconductor 6 even if the reinforcing plate 10 is provided.

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  As a result, a certain examination comprising a flexural examination, two types of one-point pressure examination, is undertaken on the integrated circuit card 1 so as to study the thickness of the reinforcing plate 10, so that the semiconductor chip 6 has a durability without significant fracture, in the form of a relationship

  with the thickness of the semiconductor chip 6.

  As shown in Fig. 3, flexural examination is performed by the following steps. The integrated circuit card 1 is mounted on a mandrel 11 having a radius of 40 mm, so that the mirror surface face 6a of the semiconductor chip 6 is positioned facing the lower side. The entire integrated circuit card 1 is pressed by a holding fixture having a circular arc so as to bend the integrated circuit card 1 according to a cylindrical outer surface of the mandrel 11. Thereafter, a stress applied to the semiconductor chip 6 is detected and calculated using finite element analysis by examination simulation, and is detected if the semiconductor chip 6

has fractures or not.

  There are two types of pressure testing, ie pressure testing at a narrow point and examination by application of pressure at an obtuse point. Each of the one-point pressure application examinations calculates a stress applied to the semiconductor chip 6 during the application of pressure on the IC card 1 where the semiconductor chip 6 (the backing plate 10) is biased by hemispherical teeth 13, 14. Each of the examinations by application of pressure at a point also detects whether the semiconductor chip 6 has fractures or not. In these examinations, the integrated circuit card 1 is mounted on a rubber plate 15 having a thickness of 20 mm, so that the mirror surface 6a

  of the semiconductor chip 6 is installed on the upper side.

  In this situation, the integrated circuit card 1 is pressed by the tooth 13 having a diameter of 1.5 mm with a pressing force of 10 N (Newton) during the examination by application of pressure at an acute point, and is pressed by the tooth 14 having a diameter of 10 mm with a force of

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  pressure of 17 N in the case of examination by application of

pressure at an obtuse point.

  Here, the reasons for mounting the integrated circuit card 1 on the mandrel 11 so that the mirror surface face 6a of the semiconductor chip 6 is installed on the lower side in the bending examination, and mounting of the integrated circuit card 1 on the rubber plate 15 so that the mirror surface face 6a of the semiconductor chip

  6 are installed on the upper side are as follows. That is,

  say that when the integrated circuit card 1 is pressed by the holding fixture 12, or by the hemispherical tooth 13 or 14, the integrated circuit card 1 is bent so that the circuit sheet face 2 takes a convex shape . In this case, it is considered that the neutral bending axis of the integrated circuit card 1 exists on the mirror surface face 6a with respect to the center of the direction of the thickness of the semiconductor chip 6, as indicated by a line with dotted lines and alternating points p in FIG. 1. As a result, a compressive stress is generated at the level of the mirror surface face 6a of the semiconductor chip 6, whereas a tensile stress is generated at the face level of

circuit surface 6b.

  Here, the mirror surface face 6a of the semiconductor chip 6 has a high hardness because this surface is made of the single crystal of the wafer, while the circuit surface face 6b has a low hardness because impurities are implanted. in this to form an integrated circuit or the fact that the surface has asperities. As a result, the semiconductor chip 6 is easily fractured when the tensile stress is applied to the IC card 1 so that the circuit surface face 6b takes a convex shape, compared to the case where the same constraint bending is applied to the IC card 1 so that the mirror surface face 6a takes a convex shape. As a result, the integrated circuit card 1 is mounted so that the circuit surface face 6a takes a convex shape when the integrated circuit card 1 is bent during the bending examination, and the examination by application

pressure in one point.

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  These examinations, including bending examination, acute pressure testing, and pressure testing at an obtuse point, correspond to characteristic load conditions during actual use. That is, various types of loads are applied to the

  integrated circuit card 1 during actual use.

  However, most of the charges can be classified as follows, that is, (A) a first case in which the user sits on a chair, the IC card 1 being in the trouser revolver pocket of the user, (B) a second case in which the integrated circuit card 1 is pressed by a relatively sharp protuberance such as the tip of a ballpoint pen, that is to say a pressure force is applied to a very narrow point of the integrated circuit card 1, and (C) a third case in which the integrated circuit card 1 in a purse or the like is pressed by a button or other of the bag or clothes, that is, a pressure force is applied to a relatively wide point

of the integrated circuit card 1.

  As a result, the bending examination shown in Fig. 3 led to the first case being analyzed, the pressure application at a narrow point as shown in Fig. 4 led to the analysis of the second case, and examination by applying pressure to an obtuse point as indicated on the

  Figure 5 led to analyze the third case.

  Figure 6 shows the experimental results of the flexion examination. Fig. 7 shows the experimental results of the acute pressure application test, and Fig. 8 shows the experimental results of the obtuse pressure application test, respectively. Here, Figs. 6A, 7A, 8A show the maximum stress in the circuit surface 6b, respectively, and Figs. 6B, 7B, 8B show the maximum stress applied to the edge portion (four edges

  peripherals) of the semiconductor chip 6, respectively.

  In these figures, the stress ranges within which the semiconductor chip 6 does not fracture are indicated with oblique lines (hatching). The reason for measuring the maximum stress of the edge portion of the chip

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  of semiconductor 6 is as follows. Since the semiconductor chip 6 is chip-shaped by dicing the wafer, a cutting surface (edge portion) of the semiconductor chip 6 can easily cause fracture due to tiny chips. As a result, the stress applied to the edge is calculated using finite element analysis by simulation of the examination and it is detected whether the

  semiconductor chip 6 has fractures or not.

  After that, a thickness range t of the reinforcing plate 10 inside which the semiconductor chip 6 does not undergo a fracture according to the relationship with the thickness T of the semiconductor chip 6 in each examination is based on the experimental results of the examinations described above including bending and applying pressure at an acute point. These ranges indicated by the oblique lines correspond to the thickness range of the reinforcing plate 6 inside which the semiconductor chip 6 hardly undergoes a fracture, even if the user is seated on a chair, the card 1 integrated circuit being in the revolver pocket of the user's trousers, a pressing force is applied

  on a very narrow point of the integrated circuit card 1.

  Fig. 9 shows a thickness range of the reinforcing plate 10 within which the semiconductor chip hardly experiences fracture in bending examination and examination by application of pressure at an acute point. In this figure, a curve C1 (which is the same as the curve C1 of the maximum stress of 350 MPa in FIG.

  limit o the semiconductor chip 6 is fractured or not.

  When an equation intended to represent the curve C1 is calculated using a least squares approximation,

  the right-hand side of the following equation (1) can be obtained.

  As a result, when the thickness t of the backing plate 10 is set within the range of the following equation (1), this can prevent the semiconductor chip 6 from fracturing.

  even if one of the above cases (A), (B) is caused.

  t> (1.04 x 10-6) T4 - (5.26 x 10-4) T3 + (1.02 x 10 - ') T2 - 9.12 T + 3.55 x 102 --- (1) In addition, a thickness range t of the reinforcing plate 10 inside which the semiconductor chip 6 does not undergo a fracture by a relationship with the thickness T of the chip

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  Semiconductor 6 in each examination is based on the experimental results of the above described examinations including bending, application of pressure at an acute point and application of pressure at an obtuse point. These ranges indicated by the oblique lines correspond to the thickness range of the reinforcing plate 6 inside which the semiconductor chip 6 hardly undergoes the fracture, even if the user is seated on a chair, the card 1 being in the revolver pocket of the user's trousers, the pressure force is applied to a very narrow point of the integrated circuit card 1, or the pressure force is applied to a relatively wide point of the

integrated circuit card 1.

  Figure 9 shows a thickness range of the reinforcing plate 10 within which the semiconductor chip hardly undergoes the fracture. In this figure, a curve C2 (which is the same as the curve C2 of the maximum stress of 380 MPa of FIG. 7a) represents a limit where the semiconductor chip 6 undergoes the fracture or not. When an equation for representing curve C2 is computed using a least squares approximation, the right-hand side of the following equation (2) can be obtained. As a result, when the thickness t of the reinforcing plate 10 is set within the range of the following equation (1), this can prevent the semiconductor chip 6 from fracturing, even if

  one of the above cases (A), (B), (C) is caused.

  t> (7.22 x 10-7) T4 - (4.0 x 10-4) T3 + (8.08 x 10 - ') T2 - 7.61T + 3.3 x 102 --- (2) In this case, the particular example of the dimensions of the

  integrated circuit card 1 will be presented hereinafter.

  [Particular example 1] Each thickness of the circuit sheet 2 and the cover sheet 4 is 125 μm, respectively. The total thickness of the integrated circuit card 1 after the two sheets 2, 4 are glued via the intermediate sheet 3 is 605 μm, the thickness of the semiconductor chip 6 is 150 μm, and the thickness of the reinforcing plate 10 is 50 μm. This particular example 1 satisfies equation (1).

  [Particular example 2] Each thickness of the circuit sheet 2 and the cover sheet 4 is 100 μm, respectively. The total thickness of the integrated circuit card 1 after the two sheets 2, 4 are glued via the intermediate sheet 3 is 627 μm, the thickness of the semiconductor chip 6 is 150 μm, and the thickness of the reinforcing plate 10 is 50 μm. This particular example 2 satisfies

two equations (1) and (2).

  The total thickness of the integrated circuit card 1 is not limited to the value described in the particular examples 1 and 2. However, taking into consideration the flexibility or the possibilities of use of the integrated circuit card 1, it is preferable to establish the total thickness of the integrated circuit card 1 within a range of 400 to 900 μm. In addition, it is preferable to establish the thickness T of the semiconductor chip 6 within a range of 10 to 30% of the total thickness of the integrated circuit card 1, and to establish the thickness of the backing plate 10 within a range of 8 to 20% of the total thickness of the integrated circuit card 1. When the integrated circuit card 1 is to be made thinner, it is preferable to thin the intermediate sheet 13 and further the semiconductor chip 6, since the circuit sheet 2 and the cover sheet 4 can be thinned only to a limited extent. In this case, a preferable thickness of

  the semiconductor chip 6 is 50 to 150 μm.

  It should be noted that the present invention is not limited to the embodiment described above, and may be

extended and modified as follows.

  That is, the total thickness of the IC card 1 may be less than 400 μm, or may be

greater than 900 pm.

  The thickness of the semiconductor chip 6 is not limited to within 50 to 150 μm. When it is necessary to thin the integrated circuit card 1, the thickness of the semiconductor chip 6 may be substantially 0.5 pm, for example, whereas when there is no need to thin the integrated circuit card 1, the thickness of the semiconductor chip 6

  can be practically 200 μm, for example.

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  The reinforcing plate 10 may be made of copper, aluminum or other instead of stainless steel. In this case, in order to substantially increase the hardness of the semiconductor chip 6 so as to prevent fracture, it is preferable to select among materials having a Young's modulus of 100 to 300 GPa. In other words, plastic material can be used if such

  plastic material has the Young's modulus described above.

  The integrated circuit card 1 is not limited to comprise the three-layer structure having the circuit sheet 2,

  the intermediate sheet 3 and the cover sheet 4.

  The backing plate 10 may be arranged on a surface of the circuit sheet 2 opposite a surface where the semiconductor chip 6 is mounted. In this case, it is preferable to stick a sheet on the circuit sheet 2 so as to

seal the reinforcement plate 10.

  In addition, the joint element 7 can be omitted.

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Claims (7)

  An integrated circuit card comprising: a circuit substrate (2) having a driver circuit (5)   a semiconductor chip (6) mounted on the circuit substrate, a reinforcing plate (10) mounted on the semiconductor chip, for reinforcing the semiconductor chip, and made of a material whose Young's modulus is at within a range of 100 to 300 [GPa], and a cover sheet (4) mounted on the backing plate, for protecting the semiconductor chip, wherein a total thickness of the laminate structure comprising the substrate circuit, the semiconductor chip, the backing plate, the cover sheet is within a range of 400 to 900 [μm], and when a thickness of the semiconductor chip is T, a thickness t of the reinforcing plate is within a satisfactory range of at least one of the following equations (1) and (2). t> (1.04 x 10-6) T4 - (5.26 x 10-4) T3 + (1.02 x 10-1) T2 - 9.12 T + 3.55 x 102 --- (1) t> (7.22 x 10-7) T4 - (4.0 x 1C-4) T3 + (8.08 x 10-1) T2 - 7.61T + 3.3 x 102 --- (2) An IC card according to claim 1, wherein the thickness t of the backing plate is inside   a range satisfying equation (1).   An IC card according to claim 1, wherein the thickness t of the backing plate is inside   a range satisfying equation (2).   4. Integrated circuit card according to any one of   Claims 1 to 3, wherein the backing plate (10)   is arranged on a surface of the circuit substrate (2) opposite a surface where the semiconductor chip (6) is mounted. 16 2787610   5. Integrated circuit card according to any one of   Claims 1 to 4, wherein the thickness of the chip of   semiconductor (6) is within a range of 50 to [Pm].   An integrated circuit card comprising: a circuit substrate (2) having a conductive circuit (5), a semiconductor chip (6) mounted on the circuit substrate, and having a thickness selected from a range of 50 at 150 [pm], a backing plate (10) mounted on the semiconductor chip, for reinforcing the semiconductor chip, and a cover sheet (4) mounted on the backing plate, for protecting the semiconductor chip wherein a total thickness of the laminate structure comprising the circuit substrate, the semiconductor chip, the backing plate, the cover sheet is within a range of 400 to 900 [μm], and when a thickness of the semiconductor chip is T, a thickness t of the reinforcing plate is selected from a range satisfying at least one of the following equations (1 and 2).   t> (1.04 x 10-6) T4 - (5.26 x 10-4) T3 + (1.02 x 10-1) T2 - 9, 12T + 3.55 x 102 --- () t > (7.22 x 10-7) T4 - (4.0 x 10-4) T3 + (8.08 x 10-1) T2 - 7.61T + 3.3 x 102 --- (2) An integrated circuit card comprising: a circuit substrate (2) having a conductive circuit (5), a semiconductor chip (6) mounted on the circuit substrate, a backing plate (10) mounted on the semiconductor chip , in order to strengthen the semiconductor chip, and made of a material whose Young's modulus is within a range of 100 to 300 [GPa], and a cover sheet (4) mounted on the plate reinforcement, in order to protect the semiconductor chip, 17 2787610   wherein, when a thickness of the semiconductor chip is T, a thickness t of the backing plate is selected from a range satisfying at least one of the following equations (1) and ", 2) .5 t> (1.04 x 10 -%) T4 - (5.26 x 10- 4) T3 + (1.02 x 10-1) T2 - 9.12 T + 3.55 x 102 --- (1) t> (7.22 x 10-7) T4 - (4.0 x 10-4) T3 + (8.08 x 10-1) T2 - 7.61T + 3.3 x 102 --- (2)