JPH02265797A - Ic card module - Google Patents

Abstract

PURPOSE:To prevent the warpage generated in an IC module and to enhance the reliability in the electrical and mechanical connection of a lead frame and an IC card substrate by providing a frame-shaped reinforcement made of a metal having elasticity on the lead frame around an IC chip. CONSTITUTION:A rectangular frame-shaped reinforcement 16 is provided on the lead frame 11 around an IC chip 14. The reinforcement 16 is composed of a non-metal material having elasticity, for example, an epoxy laminated sheet or polyimide resin and arranged so that the bonding area of the IC chip 14 and external connection terminal 13 is received inside the frame shape thereof. The thickness on the lead frame 11 of the reinforcement 16 is set so as to become almost equal to that on the lead frame of a resin started part material mentioned later. By providing the reinforcing body, an IC card module can be formed into a multilayer structure and, therefore, the warpage deformation quantity thereof can be markedly reduced as compared with conventional one.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an IC card module mounted on an IC card.

(Prior art) Conventionally, as a technology in this field, Japanese Patent Application Laid-Open No. 62-2
There was one described in Publication No. 61498. The configuration will be explained below using figures.

Figures 2 and 3 are ICs from &1 described in the above-mentioned document.
The lead frame of the card module is shown, FIG. 2 is a perspective view of the lead frame, and FIG. 3 is A-A in FIG. 2.
FIG. Further, FIG. 4 is a sectional view of a conventional IC card module.

In FIGS. 2 and 3, a lead frame 1 forms a part of an IC card module, and has a plurality of external connection terminals 2, an element mounting section 3, and a wiring section 4.

The external connection terminal 2 is provided so as to protrude from the plane formed by the wiring section 4.

As shown in FIG. 4, an IC chip 5 is mounted on the element mounting section 3, and the mounted IC chip 5 is connected to the external connection terminal 2 via a bonding wire 6 and a wiring section 4. The lead frame 1 on the side on which the IC chip 5 is mounted is resin-sealed by a resin-sealing part 7, and the fourth
An IC card module 8 as shown in the figure is configured.

The IC card module 8 configured in this manner is installed in an IC card (not shown). At that time, external connection terminal 2
The upper surface is exposed on the surface of the IC card and serves as a terminal for connecting external devices such as an IC card reader/writer. In this case, since the external connection terminal 2 protrudes from the wiring portion 4, its exposed surface is substantially flush with the surface of the IC card, and no recess is formed.

Therefore, dust and the like are prevented from adhering to the exposed surface of the external connection terminal 2, and the reliability of the contact is improved.

(Problem to be Solved by the Invention) However, in the IC card module 8 of the 3rd grade exclusive composition, there is a problem in that the resin sealing of the IC chip 5 etc. causes warping as shown in FIG. It was Shonada.

That is, when the surface of the lead frame 1 on the side where the IC chip 5 is mounted is sealed with resin by transfer molding, volume shrinkage occurs due to resin bulging and volatile matter dissipation within the mold, and the molded product is removed from the mold. Cooling contraction occurs based on the coefficient of thermal expansion of the resin immediately after cooling. Due to the contraction of these resins, the entire IC card module 8 is warped as shown in FIG. 4.

If such warpage occurs, the flatness of the back side of the lead frame 1 will be significantly impaired, and the lead frame 1 and the I
The reliability of the electrical connection with the C card board side decreases, and there is a risk that the lead frame 1 may peel off from the IC card board. In addition, since warping also occurs between the external connection terminals 2, a problem arises in that the reliability of the contacts decreases when connecting any external device.

Furthermore, when sealing the external connection terminal with resin, the surface of the external connection terminal 2 is likely to be covered with the resin, and if this is left untreated, the contact characteristics of the external connection terminal 2 will be significantly impaired.

The present invention solves the problems that the prior art had, and solves the problem of warpage that occurs in IC modules.
The present invention provides an IC card module that solves the problems of reduced reliability of electrical and mechanical connection with a C card board, and problems of warping and loss of resin coating reliability.

a frame, an IC chip fixed to the element mounting section; 1. and a resin sealing part for sealing the IC chip,
In the IC card module mounted on an IC card, a frame-shaped reinforcing body made of an elastic non-metal is provided on the lead frame around the IC chip6.Furthermore, in the second invention, I according to claim 1
In the C card module, the thickness of the reinforcing body is set to be approximately equal to the thickness of the resin sealing portion on the lead frame.

(Function) According to the first invention, since the IC card module is configured as described above, a strong three-layer structure is formed together with the rod-shaped reinforcing body frame and the resin sealing portion, and the resin sealing It functions to prevent warping and deformation caused by accompanying thermal expansion and contraction. Furthermore, since the reinforcing body is made of an elastic non-metal, it prevents short circuits caused by the reinforcing body, and
It works to prevent damage to the IC card module due to stress concentration, etc.

Furthermore, in the second aspect of the invention, the reinforcing body, which is set so as to match the thickness of the resin-sealed portion on the lead frame, acts to press the lead frame against the mold during resin-sealing. Due to this function, the contact surface between the lead frame and the molding die is set to be as thick as possible, so that the amount of warp deformation is further reduced.

Therefore, the above problem can be solved.

(Example) FIGS. 1(a) and 1(b) show an IC card module before resin sealing in a practical example of the present invention, and FIGS.
a> is its perspective view, and the same figure (b) is its top view.

Moreover, FIGS. 5(a) and 5(b) show the IC card module of FIGS.
is a perspective view of the IC chip, and FIG. cb is a perspective view of the external connection terminal side.

In FIGS. 1(a> and 1b), the lead frame 11 of this IC card module has an element mounting part 12 at approximately the center thereof, and a plurality of external connection terminals are arranged around the element mounting part 12. 13 is provided.Element mounting section 12
An IC chip 14 is fixed to the terminal, and the IC chip 14 and the external connection terminal 13 are connected to each other by a bonding wire 15 or the like.

Lead frame 1 around military RAIC chip 14
1. A quadrilateral rod-shaped reinforcing body 16 is provided on the top. The reinforcing body 16 is made of an elastic non-metal such as an epoxy laminate or polyimide resin, and is arranged so that the bonding areas of the IC chip 14 and the external connection terminals 1.3 fit inside the frame. There is. The thickness of the reinforcing body 16 on the lead frame 11 is set to be approximately equal to the thickness of the resin sealing portion on the lead frame 11, which will be described later.

Lead claim 11 provided with reinforcing body 16 in this way
The IC chip 14 side of the lead frame 11 is resin-sealed with a resin sealing part 17 as shown in FIGS. As shown in FIG. 5(a), the surface of the reinforcing body 16 is exposed, and the surface of the reinforcing body 16 and the surface of the resin sealing part 17 are substantially on the same plane.

The external connection terminal 13 side of the lead frame 11 is shown in FIG.
As shown in b), the surface of the lead frame 11 is exposed on the same plane as the resin sealing part 17.

Here, the surface of the exposed external connection terminal 13 is, for example, I
It forms a contact part with external equipment such as a C card reader/writer.

Next, a method for manufacturing the IC card module configured as described above will be explained using FIGS. 1(a) and 1(b) and FIG. 6. Figure 6 shows the IC housed in the mold.
FIG. 3 is a cross-sectional view of the card module.

First, as shown in FIGS. 1(a) and 1(b), a lead frame 11 having a predetermined shape is manufactured. This lead frame 11 is
For example, the element mounting portion 12, the external connection terminals 13, etc. are formed one by one by blessing, etching, or the like. Next, the surface of the element mounting portion 12 on the IC chip 14 mounting side, the surface of the external connection terminal 13 on the external device contact side, etc. are subjected to a process such as gold plating.

After that, the reinforcing body 16 is placed at a predetermined position on the lead frame 11.
to be fixed. This fixing is carried out by gluing the reinforcing body 16 to the lead frame 1.1, for example with epoxy adhesive or the like. Subsequently, the IC chip 14 is die-bonded onto the element mounting portion 12, and the IC chip 14 and the bonding area of the external connection terminal 13 are connected by wire bonding or the like.

Next, as shown in FIG. 6, the lead frame 1] is housed in the mold 19, and the
The C chip 14 etc. are sealed with resin. At that time, the reinforcement body 1
6 is made of an elastic non-metal as described above, and its thickness is set to be approximately equal to the thickness of the resin sealing portion 17 on the glued frame 11.
The surface thereof contacts the upper mold 19a of the cavity 20.

That is, when the molding die 19 is clamped, the surface of the reinforcing body 16 comes into close contact with the upper mold 19a, and the clamping pressure is transmitted to the lead frame 11 via the reinforcing body 16, which is an elastic body. Therefore, the lead frame 11 is in close contact with the flat mold 19b.

In such a state, if molten resin is injected into the cavity 20 through the runner 21 and the gate 22 under pressure, the IC chip 14 etc. will be sealed with the resin, and the upper mold 19a and the reinforcing body] 6 will be sealed. Between contact surfaces and lower mold 19b
This prevents resin from flowing between the contact surfaces of the lead frame 11 and the lead frame 11. In particular, by preventing the resin from flowing between the contact surfaces of the lower mold 19b and the lead frame 11, there is no possibility that the external device contact surface of the external connection terminal 13 will be covered with resin.

After the molding is completed, the lead frame 11 is taken out from the molding die 19 and separated into individual pieces to obtain a desired IC card module as shown in FIGS.

Warpage and deformation of the IC card module configured as described above will be explained using FIG. 7.

FIG. 7 is a cross-sectional view of a multilayer board model that is a simplified representation of the IC card module shown in FIGS. 5(a) and 5(b).

In the case of warpage deformation of an IC card module in which one side of the lead frame 11 is fixed to the resin side, thermal expansion/contraction characteristics are considered to be a factor that causes the deformation, and Young's modulus and thickness of the constituent materials are considered to be factors that prevent deformation. .

The magnitude of warp deformation is determined when the force that causes the deformation and the force that prevents it are balanced.

Therefore, the amount W of warp deformation based on the theoretical calculation of the multilayer plate model shown in FIG. 7 is expressed by the following equation.

C=-ΣEk (Zk -Zk-1>D=tΣEkα
k (Zk-Zk-1>Ek: Young's modulus of each layer = 1~
3 Zk: Base Z. The distance α between the lower boundaries of each layer: Thermal expansion coefficient t of each layer: Temperature difference In equation (1), the width J of the multilayer board model is assumed to be 12 mm, and the resin sealing part 17, reinforcing body 16, and lead frame 11
Young's modulus E1 to E3, thermal expansion coefficient α to α
, the thickness T1 to T3 is E 1 = 1200 kg/le
rm2E 2 = 900 kg/rtvm2E 3
= 15800 kg/rrtn2α1=1.7X10
/'C α3 ``O,, 8x 10-5x℃ '1-1=0.17 order T2 ``''0.2811111 T3. = 0, 15!I1m, then the warping deformation iw becomes w=43 μm.

On the other hand, in the case of the conventional two-layer structure as shown in FIG. When the amount of warp deformation W is determined, w-62 μm is obtained. Therefore, the multilayer plate model shown in FIG. 7 can reduce the warping deformation IW by about 30% compared to the two-layer structure shown in FIG. 4. Actually, the IC card module of this embodiment is shown in FIG.
Since the thickness of the reinforcing body 16 and the thickness of the resin sealing portion 17 on the lead frame 11 are approximately the same as shown in a) and (b), the amount of warp deformation W is further reduced.

As described above, in this embodiment, by providing the reinforcing body 16, the amount of warp deformation of the IC card module can be significantly reduced compared to the conventional case. Furthermore, by making the thickness of the reinforcing body 16 equal to the thickness of the resin sealing portion 17 on the lead frame 11, the amount of warping deformation can be further reduced, and the lead frame 11 and the lower mold 191)
Since the resin is prevented from flowing between the contact surfaces, the contact reliability of the external connection terminal 13 is improved. Furthermore, since the reinforcing body 16 is made of an elastic non-metal, it also has the advantage of not causing stress concentration or electrical short circuits.

I get ridiculed.

(a) In the above embodiment, as shown in FIG. 6, the thickness of the reinforcing body 16 was set to be approximately equal to the thickness of the resin sealing portion 17 on the lead frame 11, but the thickness is not necessarily limited to this. . That is, as shown in the cross-sectional view of the IC card module accommodated in the molding die of FIG.
The thickness of the resin sealing portion 17 may be set to be thinner than that of the resin sealing portion 17.

In this case as well, the reinforcing body 16 can sufficiently prevent warping, and the thickness of the reinforcing body 16 does not need to be strictly controlled, making it easy to manufacture the IC card module.

(b) Although the reinforcing body 16 has a quadrilateral frame shape in FIGS. It does not need to be continuous over the entire circumference of the IC chip 14, and may be partially present.

(C) The contact surface of the external connection terminal 13 with the external device is
Although it is provided on the side opposite to the IC chip 14, it may be provided on the same side as the IC nap 14. Furthermore, the external connection terminals 13 may not be provided around the IC chip 14, but may be provided at a position separate from this, but in this case, it is preferable to change the dimensions of the reinforcing body 16 according to the position of the external connection terminals 13. .

(d) The method of manufacturing the IC card module is not limited to the example shown, and the reinforcing body 16 may be fixed on the lead frame 11 after wire bonding the IC chip 14, for example. Further, other connection methods such as pants may be used instead of wire bonding.

(Effects of the Invention) As described above in detail, according to the first invention, the provision of the reinforcing body allows the IC card module to have a multilayer structure, so that the amount of warp deformation can be reduced compared to the conventional one. can be significantly reduced. Therefore, the flatness of the IC card module is maintained even after resin sealing, which improves the reliability of the electrical and mechanical connection between the lead frame and the IC card board, and also improves the reliability of the electrical and mechanical connection between the lead frame and the IC card board. Contact reliability can also be improved. Further, by forming the reinforcing body from an elastic non-metal, it is possible to prevent short circuits caused by the reinforcing body, and at the same time, it is possible to accurately prevent damage to the IC card module caused by stress concentration or the like.

According to the second invention, there is an effect that the thickness of the reinforcing body is set to be approximately equal to the thickness of the resin-sealed portion on the lead frame. Also, by increasing the thickness of the reinforcement,
Another effect is that the amount of warpage of the I'C card module is further reduced.

[Brief explanation of drawings]

1(a) and 1(b) show an IC card module before resin sealing according to an embodiment of the present invention, FIG. 1(a) is a perspective view thereof, FIG. 1(b) is a plan view thereof, and FIG. The figure shows the conventional I
A perspective view of a lead frame in a C card module,
Figure 3 is a cross-sectional view taken along line A-A in Figure 2, and Figure 4 is a conventional IC.
Cross-sectional views of the card module, FIGS. 5(a) and 5(b), show the IC card module of FIGS. 1(a) and (b) after resin sealing, and FIG. 5(a) shows the IC chip ( FIG. 6 is a cross-sectional view of the IC card module shown in FIGS. 1 (a) and (b) housed in the mold. Figure 7 shows Figures 5 (a) and (b).
) is a cross-sectional view of a multi-layer board model which is a simplified representation of the IC card module 1 of FIG. 11... Lead frame, 12... Element mounting section, 13... External connection terminal, 14...
... IC tip, 16... Reinforcement body, 17.
...Tree #i'4 stop, 19...Molding mold.

Claims (2)

[Claims] 1. The IC includes a lead frame having an element mounting part and a plurality of external connection terminals, an IC chip fixed to the element mounting part, and a resin sealing part for sealing the IC chip.
An IC card module mounted on a card, characterized in that a frame-shaped reinforcing body made of an elastic non-metal is provided on the lead frame around the IC chip. 2. 2. The IC card module according to claim 1, wherein the thickness of the reinforcing body is approximately equal to the thickness of the resin sealing portion on the lead frame.