DE10311965A1 - Flip-chip arrangement on a substrate carrier - Google Patents

Abstract

Arrangement with a substrate carrier (S) with a first surface (01) on which external contact elements (AK) are attached, a second opposite surface (02) on which chip contact elements (CK) are attached, the contact elements of both surfaces being passed through the substrate ( S) are electrically connected to one another (D) and to a chip (IC) whose side (K) provided with contact points (B) faces the second surface and is electrically connected to the chip contact elements (CK), and the thickness ( D2) of the chip is greater than the thickness of the substrate (S). DOLLAR A This enables a high dynamic and static bending reliability to be achieved.

Description

The The invention relates to an arrangement with a substrate carrier and a chip attached to it.

The increasing number of applications of chip cards require an increasing mechanical strength of the substrate carrier with the chips attached to it. A known exemplary embodiment of a substrate carrier with a chip attached thereon, for example for telephone cards or chip cards (smart cards) for security applications, is shown 2 , There, a chip is glued to a substrate carrier using an adhesive. On the opposite side of the substrate carrier there are external contacts which can be connected, for example, to a chip card reader. The substrate has openings at the location of these external contacts, so that the external contacts are connected to wires that lead to the contact points on the top of the chip.

To the Protection against oxidation, these wires are usually covered with a gold layer or made directly from gold. The substrate carrier with the one on it Chip is then inserted into a chip card so that the chip protected is. For the intimate connection of the gold wires with the external contacts or the chip contacts offer bonding methods. This is the gold wire as well as the contact point heated locally, resulting in an intimate electrical Connection between gold wire and contact point leads. Around the gold wires to protect against tearing in the event of mechanical stress on the chip card these usually additional embedded in a resin.

The However, high processing temperatures of such contacting are required a temperature-stable substrate or a temperature-stable chip and therefore cause a higher space and expense.

The The object of the present invention is an arrangement without providing the disadvantages mentioned.

This The object is achieved with the features of patent claim 1. To is an arrangement of a substrate carrier with two opposite surfaces intended. One surface has External contact elements on through the substrate with chip contact elements on the opposite surface are electrically and mechanically connected. The arrangement also has a chip provided with contact points, which is connected to the substrate carrier is that of that side provided with the contact points with the chip contact elements provided surface of the substrate carrier facing and electrically connected to the chip contact elements is. The thickness of the chip is larger than the thickness of the substrate. As a result, high mechanical stability against static bends can be achieved. Through the direct contact between the chip and the chip contact elements without additional The space required is significantly reduced by wire connections.

Further advantageous embodiments of the invention are the subject of the dependent claims.

In A further development of the invention is always the thickness of the chip larger than the sum of the thicknesses of the substrate of the external contact elements and the Chip contact elements. The substrate carrier itself is advantageous from a thin Plastic formed. An alternative embodiment is training of the substrate carrier through paper. This ensures the highest possible reliability guaranteed in mechanical, dynamic bending processes.

A The training is an advantageous embodiment of the contact the contact elements through a gold-nickel-copper metallization layer, in which gold forms the uppermost sub-layer.

The object according to the invention let yourself advantageous with a card body, which has a recess, connect to a data carrier card.

in the The following is the invention with reference to a drawing explained in detail. Show it:

1 an embodiment of the invention,

2 a known embodiment.

In 1 a substrate carrier S is shown which has two surfaces O1 and O2. Furthermore, the substrate contains through holes D, so that the holes penetrate the substrate completely. On the first surface O1, the substrate S has external contact elements AK which consist of a metal layer. On the second surface O2, the substrate carrier contains chip contact elements CK, which are electrically connected through the through holes D to the external contact elements AK. The through holes D are completely filled with a metal that is also part of the Is metal layer.

External contact elements AK, the substrate layer and the contact elements CK together a thickness D1 on the order of magnitude 100 μm. The substrate carrier S, the base material is a plastic, for example PEN, PET, PI or SR4 used has a layer thickness of approx. 75 μm. alternative let yourself this substrate carrier can also be realized with paper or another flexible material.

The Contact layers AK and CK are made of a three-component metallization layer built up. Two approx. 10 μm thick copper metallization layers are with the two surfaces of the Substrate and directly connected to each other via the through holes D. An approx. 2 μm thick nickel layer is applied to each copper layer. To the Protection against oxidation is a thin gold layer on these contacts applied, which is typically 0.05 μm or formed as a flash layer is. In addition to this variant however, other metal layers and alloys can also be used, for example palladium.

By The thickness can be varied possibly an increased stability reach the substrate carrier. The metals are deposited galvanically. With this preparation with metal layers of very small thickness is a flexible substrate carrier with great reliability realized in mechanical, dynamic bending processes.

The The arrangement also has a chip IC, the contacts of which Chip contact elements CK over the bumps B is connected. For this is the one provided with the contact points Side of the chip IC provided with the chip contact elements CK surface O2 of the substrate carrier S faces and thus forms a flip chip. The bumps B are raised contact points, which are made of metal, which have a different degree of hardness across from has the chip contact elements CK. For example, the chip contact element CK are made of a softer material than the Bumps B. By exercise a pressure when contacting the chip IC with the chip contact elements CK thus easily bumps B into chip contact elements CK pressed. This creates an intimate electrical contact. of course is it is also possible for the bumps B and the chip contact elements CK use the same metals. Another alternative embodiment is the use of electrical Adhesive connections, such as conductive silver, to strengthen the contact.

to Fixing the chip IC on the substrate S is an adhesive G. intended. This can be, for example, a resin or a softer one Plastic. It makes sense to apply the adhesive around the chip contact elements CK around to arrange the electrical contact between To protect chip IC and chip contact element CK and on the other hand the chip Connect IC to the substrate. To increase the contact strength can the contact areas again coated with conductive silver or a similar substance become.

The Thickness D2 of the so-called flip chip IC in this arrangement is clear larger than the thickness D1 of the sum of the substrate S and the contact elements CK and AK. This means that even with a mechanical static load the reliability given the order. Through the direct contact of the chip IC with the chip contact elements CK and the omission of additional Contact wires are overall thinner Modules can be manufactured without having to accept a lower load capacity to have to.

Thereby is for example a disk card producible that a card body having a recess and the substrate carrier arrangement according to the invention. The substrate carrier is arranged in the recess so that the chip placed on it extends into the recess. This makes an overall thinner disk card realizable. To add that the Invention not on the arrangement with a disk card limited is. The key idea is rather the arrangement between a carrier and a chip thereon, which is arranged so that its Contacts on the the carrier facing side and the chip is always a greater thickness than the carrier has.

(IC):

chip

(CK):

Chip contact elements

(W):

wire

(G):

adhesive

(S):

substrate carrier

(AK):

External contact elements

(B):

Bump

(D1):

thickness of the substrate carrier

(D2):

thickness of the chip

(O1, O2):

surfaces

(D):

bushings

(K):

Contact

Claims (9)

Arrangement with a substrate carrier (S) with a first surface (O1) on which external contact elements (AK) are attached, a second opposite surface (O2) on which chip contact elements (CK) are attached, the contact elements of both surfaces being passed through the substrate ( S) therethrough are electrically connected to one another (D), and to a chip (IC) whose side (K) provided with contact points (B) faces the second surface and is electrically connected to the chip contact elements (CK), and the thickness (D2 ) of the chip is greater than the thickness of the substrate (S). Arrangement according to claim 1, characterized in that the Thickness (D2) of the chip (IC) is greater than the sum of the thicknesses (D1) from the substrate (S), the external contact elements (AK) and the chip contact elements (CK). Arrangement according to claim 1 or 2, characterized in that the substrate carrier (S) is formed from a plastic. Arrangement according to claim 1 or 2, characterized in that the substrate carrier (S) is made of paper. Arrangement according to one of the preceding claims, characterized characterized that the interspaces between the chip contact elements (CK) and the chip (IC) with a filled with elastic adhesive (G) are who intimately connects the chip (IC) with the substrate carrier (S). Arrangement according to one of the preceding claims, characterized characterized that the Contact points (B) of the chip (IC) are formed from a metal, the one to the chip contact elements (CK) different degrees of hardness having. Arrangement according to one of claims 1 to 6, characterized in that that the Contact points (B) of the chip (IC) with an electrically conductive adhesive are trained. Arrangement according to one of claims 1 to 7, characterized in that that the Contact elements formed from a gold-nickel-copper metallization layer are, with gold forming the uppermost sub-layer. Arrangement according to one of claims 1 to 8, characterized in that one Card body, the has a recess in which the substrate carrier is introduced so that the chip protrudes into the recess.