Thin electronic device having an integrated circuit chip and a power battery and a method for producing same

A method for producing an information card by printing an electroconductive pattern and a first electrode surface of a battery on a first cover sheet, applying a battery activator onto the first electrode surface, resting an electrolyte-impregnated separator onto the first electrode surface, fixing an IC chip to the electroconductive pattern in a predetermined position, printing a second electrode surface of the battery on a second cover sheet, applying a battery activator onto the second electrode surface, and lapping and sticking the first and second cover sheets together and cutting them into a predetermined size.

Field of the Invention 
The present invention relates to a thin electronic device having an 
integrated circuit chip and a power battery for supplying electric power 
to the integrated circuit chip, as well as a method for producing same. 
Description of the Prior Art 
Recently, with the tendency to thinning of small-sized electronic devices, 
there have been developed card-type electronic calculators having an 
integrated circuit chip between resin sheets and a power battery for 
supplying electric power to the integrated circuit chip, as well as thin 
electronic devices such as IC card having a memory function. 
Heretofore, a button- or coin-shaped battery has been used in small-sized 
electronic devices. The thickness of such thin electronic devices is 
defined to be a maximum of 0.80 mm by JIS. But the use of a button- or 
coin-shaped battery in a thin electronic device has heretofore made it 
difficult to fabricate the electronic device within the said rated value 
of thickness. 
Recently, moreover, applications of such IC card have been considered, for 
example, to a theft detecting system or an automatic goods sorting system, 
as disclosed in Japanese Patent Publication No. 22997/84. However, since 
it is necessary to use a large number of IC cards as consumables, there 
has arisen the necessity of mass-producing IC cards inexpensively. 
According to the prior art, the body of a thin electronic device and a 
battery are produced separately and thereafter the battery is inserted 
into the body. This method, however, is very troublesome and poor in 
productivity, leading to increase of cost. 
SUMMARY AND OBJECT OF THE INVENTION 
Accordingly, it is one object to provide a card-type electronic device and 
its manufacturing method which overcomes the above-described disadvantage. 
It is another object to provide a card-type electronic device and its 
manufacturing method which enables the device to be thinner than the 
conventional one. 
It is still another object to provide a cardtype electronic device and its 
manufacturing method which makes it easy and low in cost to manufacture 
the device. 
According to one aspect of the present invention there is provided a method 
for producing an information card, comprising: 
a first printing step of forming by printing an electroconductive pattern 
and a first electrode surface of a battery on a first cover sheet; 
a first application step of applying a battery activator onto the first 
electrode surface; 
a resting step of resting an electrolyte-impregnated separator onto the 
first electrode surface; 
a fixing step of fixing an IC chip to the electroconductive pattern in a 
predetermined position; 
a second printing step of forming by printing a second electrode surface of 
the battery on a second cover sheet; 
a second application step of applying a battery activator onto the second 
electrode surface; and 
a cutting step of lapping and sticking the first and the second cover sheet 
together and cutting them into a predetermined size. 
According to another aspect of the present invention there is provided a 
method for producing an information card, comprising the steps of: 
printing an electroconductive pattern and first and second electrode 
surfaces of a battery onto integrally-formed first and second cover sheet 
portions; 
applying an anodic active material and a cathodic active material onto the 
first and second electrode surfaces, respectively; 
fixing an IC chip to the electroconductive pattern in a predetermined 
position; 
resting an electrolyte-impregnated separator onto one of the first and 
second electrode surfaces; and 
folding the first and second cover sheet portions so as to be superposed 
one upon the other and cutting them into a predetermined size. 
According to a further aspect of the present invention there is provided a 
thin electronic device including: 
a first cover sheet with a first electrode surface of a battery formed 
thereon; 
a second cover sheet with a second electrode surface of the battery formed 
thereon; 
an anodic active material applied onto the first electrode surface; 
a cathodic active material applied onto the second electrode surface; 
a separator impregnated with electrolyte; 
a circuit member positioned between the first and the second cover sheet 
and operated by the battery; and 
a connecting conductor formed on the first and the second cover sheet to 
connect the first and the second electrode surface with the circuit 
member, 
the anodic active material and the cathodic active material being opposed 
to each other through the separator, the first and the second cover sheet 
being integrally laminated together to hold the circuit member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 is a schematic view for explaining the method for producing an 
information card according to the present invention. An example of a 
concrete structure of the information card thereby produced is shown in a 
plan view of FIG. 2(a), a sectional view of FIG. 2(b) and a separated side 
view of FIG. 2(c). 
Patterns on the information card surface in the manufacturing steps of [I] 
to [V] are shown in FIG. 3. 
For example, as shown in the plan view of FIG. 2(a) and sectional view of 
FIG. 2(b), the information card comprises a back-side cover sheet 
(hereinafter referred to also as the first cover sheet) 1 and a 
surface-side cover sheet (also as the second cover sheet hereinafter) 2. 
In the card of this embodiment, an adhesive sheet 3 is stuck on the upper 
surface of the surface-side cover sheet 2 to display the kind of card. 
Between the first and the second cover sheet there are provided an 
electroconductive pattern 4, a flat battery 5 and an IC chip 6, and for 
thinning purpose, a hole 2A is formed in the second cover sheet 2 so that 
the IC chip 6 is fitted therein when the first and the second cover sheet 
are lapped together. 
Part of the electroconductive pattern 4, which is connected to the IC chip 
6, serves as a pair of antennas (dipole antennas) 4A.sub.2 which change in 
characteristic impedance according to the data stored in the IC memory, 
while wider area portions thereof serve as positive and negative electrode 
surfaces 4A.sub.1, 4B.sub.1. 
As best seen in FIG. 2(c), the battery 5 is formed by applying active 
materials 5A and 5B (Zn, MnO.sub.2) of the battery in the state of gel 
onto the electrode surfaces 4A.sub.1 and 4B.sub.1 which are formed by the 
printing technique or the like on the first and second cover sheets 1, 2, 
and then sandwiching an electrolyte-impregnated separator 5C in between 
the cover sheets 1 and 2. 
On the outer surface of the first cover sheet 1 there may be formed a 
magnetic film 7 according to ISO standards as in ordinary magnetic cards. 
An embodiment of the present invention for producing such information card 
as mentioned above will be described hereinunder with reference to FIG. 1. 
In FIG. 1, the numeral 11 denotes a band-like cover sheet (A) formed of 
polyethylene terephthalate (PET) or polypropylene (P.P) and having a 
thickness of about 50 .mu.m. The cover 11 is drawn out by a roll in the 
illustrated direction and fed to a magnetic stripe printing section, 
wherein a magnetic film area according to ISO standards is formed on the 
lower surface of the cover sheet 11(A). 
Numeral 13 denotes a screen printing section (A) for forming a wiring 
pattern on the upper surface of the cover sheet 11. In the screen printing 
section 13, such a wiring pattern as shown in FIG. 3(a) is printed to the 
cover sheet 11, using an electroconductive coating material such as, for 
example, pasty carbon, copper which has been made pasty, or pasty mercury. 
The portion 4A.sub.1 of this wiring pattern represents an electrode surface 
[4A.sub.1 in FIG. 2(c)] serving as a negative (-) pole of the battery in 
the information card, while the portion 4A.sub.2 represents an 
electroconductive surface serving as antenna. 
Numeral 14 denotes an active material applying section for applying zinc 
(Zn) gel acting as an activator in the battery to the portion 4A.sub.1 
which serves as an electrode surface as in FIG. 3(a), and in the portion 
indicated by rightwards oblique lines in FIG. 3(b), Zn gel 5A is applied 
onto the upper surface of the wiring pattern 4A.sub.1 in a thickness of 
about 50 .mu.m. 
Numeral 15 denotes a separator sheet in the battery which sheet is formed 
by kraft paper for example. The separator sheet 15, which is rolled, 
passes through an electrolyte impregnating section 16, whereby it is 
impregnated with electrolyte, e.g. ZnCl.sub.2. 
The thus electrolyte-impregnated separator 5C is cut into a predetermined 
size in a cutting section 17, then in a separator sticking section 18 it 
is placed on the electrode surface 4A.sub.1 of the wiring pattern, as 
shown in FIG. 3(c). 
By the above continuous steps there is constituted the first cover sheet 1 
(surface A). 
Then, in a mask mounting section 19, as shown in FIG. 3(c), a frame 8 is 
stuck to the first cover sheet having the surface A so as to slightly 
raise the peripheral portion of the wiring pattern. Further, in a hardener 
applying section 20, a small amount of a hardener 9 is applied to the 
first cover sheet in a position in which the IC chip 6 is to be fixed. 
At this time, a polyester-based hot melt adhesive is screen-printed to the 
outer peripheral portion of the electrode surface 4A.sub.1 . 
Numeral 21 denotes an IC chip packaging machine. IC chips 6 extruded one by 
one from the IC chip packaging machine 21 are each pushed against the 
wiring pattern in a predetermined position. For example, as shown in the 
enlarged view of FIG. 4, lead terminals of the IC chip 6 are formed as 
bumps 6A, which are pushed against the wiring pattern 4 in predetermined 
positions. Then, infrared ray is radiated from an infrared ray radiating 
section 22 to the pre-applied hardener 9 to thereby fix the first cover 
sheet 1 and the IC chip 6 together. 
Since the hardener 9 hardens and contracts upon radiation of infrared ray, 
the bumps 6A and the wiring pattern 4 are held in a good electrically 
conducted state. 
The cover sheet of the surface A shown in FIG. 3(d) with the IC chip 6, 
battery active material and separator formed thereon is then lapped with a 
cover sheet 23 which serves as the second cover sheet 2 and both are stuck 
together. 
More specifically, the cover sheet (B) (PET or P.P) 23, which is rolled, is 
drawn out in the arrowed direction and fed to a puncher 24, in which there 
are formed an aperture B.sub.1 for IC chip and apertures B.sub.2 for 
antenna contact, as shown in FIG. 3(e). 
The aperture B.sub.1 is formed in the position corresponding to the mounted 
position of the IC chip fixed to the cover sheet of the surface A as 
mentioned above, while the apertures B.sub.2 are formed in the positions 
corresponding to the antenna areas (4A.sub.2, 4A.sub.2). 
The cover sheet (B) thus formed with the apertures B.sub.1 and B.sub.2 is 
then fed to a screen printing section (B) 25, in which an 
electroconductive wiring pattern such as that shown in FIG. 3(f) is 
printed to the cover sheet. 
The greater part of the wiring pattern is in corresponding relation to the 
electrode surface (4A.sub.1) of the surface A, forming a positive (+) 
electrode surface [4B.sub.1 in FIG. 2(c)] of the battery. 
Then, in an active material applying section (B) 26, for example zinc oxide 
5B (ZnO.sub.2) which is in the state of gel is applied as a depolarizer to 
the electrode surface of the surface B in a thickness of about 50 .mu.m to 
form the cover sheet of FIG. 3(g). 
Preferably, at this time, a polyester-based hot melt adhesive is 
screen-printed also to the outer peripheral portion of the electrode 
surface (4B.sub.1). 
This cover sheet (B) of the surface B and the foregoing cover sheet (A) of 
the surface A are lapped together and united, at station 27, for example 
by heat-treating the two at 130.degree. C. for about 15 minutes or by an 
ultrasonic fusion-bonding technique. At this time, the battery electrode 
surfaces are completely sealed by the hot melt adhesive. 
In this case, it goes without saying that both sheets should be lapped 
together and united for registration between the pattern on the surface A 
and that on the surface B and in such a position as to permit the IC chip 
6 to be embedded in the aperture B.sub.1. 
Numeral 28 denotes an adhesive tape, which is stuck, at station, to cover 
the apertures B.sub.1 and B.sub.2 of the cover sheet (B) which has been 
rendered integral with the other cover sheet by fusion-bonding for 
example. 
Lastly, the integral sheet member is cut into a predetermined size (e.g. a 
size according to ISO standards) by means of a cutter 30 to obtain such 
information card as shown in FIG. 2. 
Although in the information card manufacturing method described above the 
cover sheets (11, 23) of the surfaces A and B which constitute the 
information card are fed separately, there may be used cover sheets (A) 
and (B) which are in a united state from the beginning. 
More specifically, as shown in FIG. 5(a), a cover sheet 31 serving as both 
surfaces A and B has a groove G which permits folding upwards and 
downwards with respect to a central line. The surface of the cover sheet 
31 is divided into surfaces A and B on both sides of the groove G, and 
wiring patterns 4A and 4B are printed on the surfaces A and B, 
respectively, using an electroconductive coating material. 
As previously noted, Zn gel is applied to an electrode surface 4A.sub.1 of 
the wiring pattern 4A, while ZnO.sub.2 gel is applied to an electrode 
surface 4B.sub.1 of the surface B. And as shown in FIG. 5(b), a separator 
5C impregnated with electrolyte is put on the surface B, and apertures 
B.sub.1 and B.sub.2 are formed on the same surface. 
Further, an IC chip 6 is fixed to the wiring pattern on the surface A using 
a hardener as noted previously and there is formed such cover sheet as 
shown in FIG. 5(b). The wiring patterns on the surfaces A and B of this 
cover sheet are connected together through an electroconductive path 4C 
extending across the groove G. 
The cover sheet of FIG. 3(b) is folded along the groove G as shown in FIG. 
3(c), to superpose the surfaces A and B together to form an information 
card. 
Also in this second embodiment there are used most of the devices used in 
the manufacturing method illustrated in FIG. 1. The second embodiment is 
advantageous in that the screen printing sections 13, 25 and the active 
material applying sections 14, 26 can be gathered at one place, thus 
permitting further simplification of the manufacturing system.