EP1789914A1

EP1789914A1 - Chip comprising different chip contacts for different operating modes

Info

Publication number: EP1789914A1
Application number: EP05775726A
Authority: EP
Inventors: Erich Pischler; Joachim Schober
Original assignee: Koninklijke Philips Electronics NV
Current assignee: NXP BV
Priority date: 2004-08-31
Filing date: 2005-08-24
Publication date: 2007-05-30
Also published as: JP2008511891A; WO2006024990A1; CN101048789A; CN100498830C; KR20070068354A

Abstract

Provided in a chip (20) for a data carrier (1) are contactless operating mode chip contacts (24, 25) and contact operating mode chip contacts (26, 27, 28, 29, 30, 31, 32, 33), wherein the contactless operating mode chip contacts (24, 25) and at least some of the contact operating mode chip contacts (26, 27, 28, 29, 30, 31, 32, 33) each have a contact head (38, 39, 40, 41, 42, 43, 44, 45, 46, 47), wherein the head height (H) of the contact heads (38, 39) of the contactless operating mode chip contacts (24, 25) is greater than the head height (h) of the contact heads (40 to 47) of the contact operating mode chip contacts (26, 27, 28, 29, 30, 31, 32, 33).

Description

Chip comprising different chip contacts for different operating modes

FIELD OF THE INVENTION

The invention relates to a chip, which chip is provided and designed for use in various chip cards, which chip cards in a first embodiment are suitable only for a contactless operating mode and in a second embodiment are suitable only for a contact operating mode and in a third embodiment are suitable both for the contactless operating mode and for the contact operating mode, and which chip has a semiconductor body and an integrated circuit formed in the semiconductor body and a passivation layer designed to protect the integrated circuit and contactless operating mode chip contacts and contact operating mode chip contacts, which chip contacts each have a contact layer lying below the passivation layer. The invention furthermore relates to a chip card comprising a chip.

BACKGROUND OF THE INVENTION

A chip of the type mentioned in the first paragraph is commercially available from the Applicant in various design variants and is therefore known. The known chip is used in various variants of chip cards, and specifically in a first variant of chip cards which have been designed and used only for a contactless operating mode, and in a second variant of chip cards which have been designed and used only for a contact operating mode, and in a third variant of chip cards which have been designed and used both for a contactless operating mode and for a contact operating mode. In the known chip, the design of the contactless operating mode chip contacts and of the contact operating mode chip contacts is such that all these chip contacts have just one contact layer lying below the passivation layer. On account of this, all of these chip contacts are suitable only for connecting to associated chip card contacts by means of a wire bond technology, and this represents an undesirable restriction. Moreover, at least the areas of the contact layers which are accessible to the bond wires must be designed to be resistant to corrosion and other negative influences, and this entails an additional outlay.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the invention to avoid the above-described difficulties which arise in a chip of the type mentioned in the first paragraph and consequently also in a chip card of the type mentioned in the second paragraph, and to provide an improved chip and an improved data carrier.

In order to achieve the abovementioned object, a chip according to the invention is provided with features according to the invention so that a chip according to the invention can be characterized as follows, namely:

A chip, which chip is provided and designed for use in various chip cards, which chip cards in a first embodiment are suitable only for a contactless operating mode and in a second embodiment are suitable only for a contact operating mode and in a third embodiment are suitable both for the contactless operating mode and for the contact operating mode, and which chip has a semiconductor body and an integrated circuit formed in the semiconductor body and a passivation layer designed to protect the integrated circuit and contactless operating mode chip contacts and contact operating mode chip contacts, which chip contacts each have a contact layer lying below the passivation layer, wherein the contactless operating mode chip contacts and at least some of the contact operating mode chip contacts each have a contact head which is connected to the contact layer and projects through a hole in the passivation layer, and wherein each contact head has a given head height in relation to the region of the passivation layer adjacent to the contact head, and wherein the head height of the contact heads of the contactless operating mode chip contacts is greater than the head height of the contact heads of the contact operating mode chip contacts, s

In order to achieve the abovementioned object, in a chip card comprising a chip, the chip card is provided with a chip according to the invention.

Providing the features according to the invention means that both the contactless operating mode chip contacts and also at least some of the contact operating mode chip contacts have a contact head, wherein all the contact heads can be produced by means of a single manufacturing method, so that very simple and cost-effective manufacture is ensured. The fact of providing the contact heads in the abovementioned chip contacts means that, in a simple manner, by virtue of the fact that the contact heads of the contactless operating mode chip contacts have a greater head height, it is possible to ensure that a stable and aging-resistant electrically conductive connection which can be produced in a simple manner using flip-chip technology and takes up only a small overall thickness can be established between the contactless operating mode chip contacts and terminals of transmission means which are assigned to these contactless operating mode chip contacts, which transmission means are provided and designed for the contactless transmission of signals. Furthermore, providing the features according to the invention means that, in the case where the contactless operating mode chip contacts are connected in flip-chip technology to the terminals of transmission means of a data carrier and the data carrier is designed and used only for a contactless operating mode, it is not possible for the contact operating mode chip contacts, which are not used in this case, to give rise to any disruptive effects, in particular to any short circuits with the transmission means for the contactless transmission of signals and data, and in the case of the contact operating mode chip contacts, which are not used here and are provided with a contact head, the contact layers of these contact operating mode chip contacts are well protected against environmental influences and other disruptive influences by means of the contact heads which are present in any case, so that corrosion and other undesirable changes to the contact layers is prevented without any separate protection means being required for this purpose. Furthermore, providing the measures according to the invention means that, for the case where the chip according to the invention is provided either in a data carrier according to the invention which is designed and used only for a contact operating mode, or in a data carrier according to the invention which is designed and used both for the contactless operating mode and for the contact operating mode, the contact operating mode chip contacts are suitable, by means of the contact heads having a smaller head height, for establishing in a simple manner a wire bond connection between the small contact heads of the contact operating mode chip contacts and countercontacts of the data carrier which are assigned to these contact operating mode chip contacts and are accessible from outside the data carrier in a known manner, wherein the other contact heads with their greater head height fulfill, as a result of the greater head height, a certain protection function for the bond wires connected to the smaller contact heads.

In a chip according to the invention, the head height of the contact heads of the contactless operating mode chip contacts may be greater than 25 μm and may for example have values of between 30 μm and 50 μm. However, it has proven to be highly advantageous if the head height of the contact heads of the contactless operating mode chip contacts lies in a range between 15 μm and 25 μm. Such contact heads require relatively little manufacturing time and material in relation to their large head height. However, such a design is particularly advantageous since, if the contactless operating mode chip contacts are connected to countercontacts of transmission means of a chip card by means of flip-chip technology, on the one hand a sufficiently large spacing exists between the contactless operating mode chip contacts and the countercontacts to receive a so-called underfill layer, and on the other hand the advantage of a small overall thickness is obtained. Moreover, the manufacturing tolerances of small contact heads are lower, as a result of which the reliability of the mechanical connections and consequently of the electrical connections is increased.

In a chip according to the invention, the head height of the contact heads of the contact operating mode chip contacts may be greater than 10 μm and may for example have values of between 12 μm and 30 μm. However, it has proven to be highly advantageous if the head height of the contact heads of the contact operating mode chip contacts lies in a range between 1 μm and 10 μm. Such contact heads require relatively little manufacturing time and material in relation to their large head height. However, such a design is particularly advantageous since a large difference is achieved between the greater head height of the contact heads of the contactless operating mode chip contacts and the smaller head height of the contact heads of the contact operating mode chip contacts, as a result of which a greater degree of safety against undesirably short-circuited contact operating mode chip contacts on account of manufacturing tolerances is provided.

In a chip according to the invention, it has been found during test experiments that it has proven to be particularly advantageous if the head height of the contact heads of the contactless operating mode chip contacts is 18 μm.

In a chip according to the invention, it has furthermore been found during test experiments that it has proyen to be particularly advantageous if the head height of the contact heads of the contact operating mode chip contacts is 5 μm. In a chip according to the invention, the contact heads may be made of silver or palladium. However, it has proven to be particularly advantageous if all the contact heads are made of gold and are produced by means of an electroplating method. This is particularly advantageous because means and measures which have been known for a long time per se are used to manufacture the contact heads of a chip according to the invention. The abovementioned aspects and further aspects of the invention emerge from the example of embodiment described below and are explained with reference to this example of embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further described with reference to an example of embodiment shown in the drawing to which, however, the invention is not restricted.

Fig. 1 schematically shows, in a view from above, a data carrier, namely a chip card comprising a chip according to one example of embodiment of the invention.

Fig. 2 shows, in a view from above and on a larger scale than Fig. 1, part of the chip card of Fig. 1, said part containing the chip.

Fig. 3 shows, in a section along the line III-III in Fig. 2, the part of the chip card shown in Fig. 2 with the chip.

DESCRIPTION OF EMBODIMENTS

Figs. 1, 2 and 3 show a chip card 1 which has a card body 2 which has been manufactured by means of a lamination process using a plurality of films. The card body 2 may also have been manufactured by means of an injection-molding process. The chip card 1 is designed and suitable for carrying out both a contactless operating mode and a contact operating mode. For this reason, the chip card 1 firstly has a transmission coil 3 embedded in the card body 2 as a contactless transmission means for transmitting signals and data, and secondly has a contact array 4. The transmission coil 3 has four (4) coil windings 5, 6, 7, 8 and two coil terminals 9, 19. The contact array 4 has eight (8) card contacts 10, 11, 12, 13, 14, 15, 16, 17, which card contacts 10, 11, 12, 13, 14, 15, 16, 17 are accessible from outside the chip card 1 for countercontacts of a read/write station, so that contact transmission of ' signals and data is possible. The eight (8) card contacts 10, 11, 12, 13, 14, 15, 16, 17 of the contact array 4 are provided on a carrier 18 of the contact array 4, which carrier 18 is made of an electrically insulating material. In the present case, the carrier 18 is made of a printed board material. However, the carrier 18 may also be formed by a plastic film. The provision of such a transmission coil 3 and of such a contact array 4 in chip cards has been known for a long time per se, and therefore no further details in this respect are given here.

The chip card 1 furthermore contains a chip 20 which is not shown in Fig. 1 but rather only in Figs. 2 and 3. The chip 20 is shown here to be larger in terms of its chip surface in relation to the contact array 4 than the chip 20 is in reality. The thickness ratios shown in Fig. 3 are thus not realistic but rather have been selected to be larger for the sake of clarity. The chip 20 is provided and designed for use in various chip cards. In the case shown in Figs. 1 to 3, the chip card 1 is designed and suitable for carrying out both a contactless operating mode and a contact operating mode, as mentioned above. The chip 20 may however also be used in a chip card which is suitable only for a contactless operating mode. The chip 20 may furthermore also be used in a chip card which is suitable only for a contact operating mode.

The chip 20 has a semiconductor body 21. An integrated circuit 22, shown schematically in Fig. 3, is formed in the semiconductor body 21. The chip 20 furthermore has a passivation layer 23, which is essentially designed to protect the integrated circuit 22. In the present case, the chip 20 furthermore has two (2) contactless operating mode chip contacts 24 and 25 and eight (8) contact operating mode chip contacts 26, 27, 28, 29, 30, 31, 32, 33. The aforementioned ten (10) chip contacts 24 to 33 each have a contact layer lying below the passivation layer 23, of which contact layers only some are shown in Fig. 3 and can be seen in Fig. 3, namely the contact layers of the contacts 24, 25, 27, 31, which contact layers are provided with the references 34, 35, 36, 37.

The chip 20 particularly advantageously has a design in which each contactless operating mode chip contact 24, 25 and each contact operating mode chip contact

26, 27, 28, 29, 30, 31, 32, 33 has a contact head which is connected to the contact layer 34, 35, 36, 37 and projects through a hole in the passivation layer 23. The aforementioned holes in the passivation layer 23 can be seen from Fig. 3, but are not provided with references. The abovementioned contact heads are provided with the references 38, 39, 40, 41, 42, 43, 44, 45, 46, 47. Each contact head 38 to 47 has a given head height in relation to the region of the passivation layer 23 adjacent to the respective contact head 38 to 47. In respect of the contact heads, it should also be mentioned that not all the contact operating mode chip contacts 26, .

27, 28, 29, 30, 31, 32, 33 necessarily have to have a contact head 40 to 47 which is connected to the contact layer 34, 35, 36, 37 and projects through a hole in the passivation layer 23, but rather it is also possible for only some of the contact operating mode chip contacts 26, 27, 28, 29, 30, 31, 32, 33 to have a contact head, for example if only some of the contact operating mode chip contacts 26, 27, 28, 29, 30, 31, 32, 33 are actually provided and used for connecting to chip card contacts, because then the contact operating mode chip contacts which are not used may be designed without a contact head.

In the chip 20, the head height H of the contact heads 38, 39 of the contactless operating mode chip contacts 24, 25 is particularly advantageously greater than the head height h of the contact heads 40 to 47 of the contact operating mode chip contacts 26 to 33. In the chip 20, the greater head height H of the contact heads 38, 39 of the contactless operating mode chip contacts 24, 25 is nominally selected to be 18 μm. The smaller head height h of the contact heads 40 to 47 of the contact operating mode chip contacts 26 to 33 is nominally selected to be 5 μm. All ten (10) contact heads 38 to 47 are made of gold and have been produced by means of an electroplating method. The ten (10) contact heads 38 to 47 may have been produced in a different way, for example by means of a printing method. However, it is advantageous if the contact heads 38 to 47 are formed by so-called bumps, in particular gold bumps.

The contact heads 38, 39 of the contactless operating mode chip contacts 24, 25 are connected to the coil terminals 9, 19 by means of a flip-chip technology, wherein an underfill (not shown in any greater detail) is provided between the passivation layer 23 and the transmission coil 3, said underfill consisting of a plastics material. The contact heads 40 to 47 of the contact operating mode chip contacts 26 to 33 are electrically conductively connected to the card contacts 10, 11, 12, 13, 14, 15, 16, 17 by means of a wire bond technology using in each case one bond wire 48, 49, 50, 51, 52, 53, 54, 55, wherein the bond wires 48, 49, 50, 51, 52, 53, 54, 55 are each passed through a hole 56, 57, 58, 59, 60, 61, 62, 63 in the carrier 18 of the contact array 4.

The advantages mentioned in the introductory part of the description are obtained in the chip 20 and in the chip card 1. At least some of these advantages are also obtained when the chip 20 is used either in a chip card 1 which has only a contact array 4 and no transmission coil, or in a chip card 1 which has only a transmission coil 3 and no contact array.

In the chip 20 and the chip card 21, the fact that all ten (10) chip contacts 24 to 33 each have a contact head 38 to 47, respectively, has provided the advantage that for co¬ operation with the contact heads, which are additionally used for testing purposes, use can be made of identically designed test needles of a test device (probe card), i.e. test needles with rounded ends.

Claims

1. A chip (20), which chip (20) is provided and designed for use in various chip cards (1), which chip cards (1) in a first embodiment are suitable only for a contactless operating mode and in a second embodiment are suitable only for a contact operating mode and in a third embodiment are suitable both for the contactless operating mode and for the contact operating mode, and which chip (20) has a semiconductor body (21) and an integrated circuit (22) formed in the semiconductor body (21) and a passivation layer (23) designed to protect the integrated circuit (22) and contactless operating mode chip contacts (24, 25) and contact operating mode chip contacts (26, 27, 28, 29, 30, 31, 32, 33), which chip contacts (24, 25, 26, 27, 28, 29, 30, 31, 32, 33) each have a contact layer (34, 35, 36, 37) lying below the passivation layer (23), wherein the contactless operating mode chip contacts (24, 25) and at least some of the contact operating mode chip contacts (26, 27, 28, 29, 30, 31, • 32, 33) each have a contact head (38, 39, 40, 41, 42, 43, 44, 45, 46, 47) which is connected to the contact layer (34, 35, 36, 37) and projects through a hole in the passivation layer (23), and wherein each contact head (38, 39, 40, 41, 42, 43, 44, 45, 46, 47) has a given head height (H, h) in relation to the region of the passivation layer (23) adjacent to the contact head (38, 39^ 40, 41, 42, 43, 44, 45, 46, 47), and wherein the head height (H) of the contact heads (38, 39) of the contactless operating mode chip contacts (24, 25) is greater than the head height (h) of the contact heads (40, 41, 42, 43, 44, 45, 46, 47) of the contact operating mode chip contacts (26, 27, 28, 29, 30, 31, 32, 33).

2. A chip (20) as claimed in claim 1, wherein the head height (H) of the contact heads (38, 39) of the contactless operating mode chip contacts (24, 25) lies in a range between 15 μm and 25 μm.

3. A chip (20) as claimed in claim 1, wherein the head height (h) of the contact heads (40, 41, 42, 43, 44, 45, 46, 47) of the contact operating mode chip contacts (26, 27, 28, 29, 30, 31, 32, 33) lies in a range between 1 μm and 10 μm.

4. A chip (20) as claimed in claim 2, wherein the head height (H) of the contact heads (38, 39) of the contactless operating mode chip contacts (24, 25) is 18 μm.

5. A chip (20) as claimed in claim 3, wherein the head height (h) of the contact heads (40, 41, 42, 43, 44, 45, 46, 47) of the contact operating mode chip contacts (26, 27, 28, 29, 30, 31, 32, 33) is 5 μm.

6. A chip (20) as claimed in any of claims 1 to 5, wherein all the contact heads (38, 39, 40, 41, 42, 43, 44, 45, 46, 47) are made of gold and are produced by means of an electroplating method.

7. A chip card (1) comprising a chip (20), wherein the chip card (1) is provided with a chip (20) as claimed in any of claims 1 to 6.