Technology of production of EMV cards

Payment card as a technological product

Payment cards from the point of view of manufacturing technology and operating principles are divided into magnetic stripe cards, microprocessor cards (other names are “smart cards”, “chip cards”) and optical memory cards (laser). Let’s consider the main points of the technology of manufacturing and functioning of each of the varieties of modern cards, as well as the technology of production of blanks, from which cards are then made.

Technology of production of magnetic stripe cards

The production process of magnetic stripe cards can be divided into three stages:
* the layout of the multilayer base of the cards, its integration into a common package and the pressing of magnetic strips (Fig. 1) (these operations are performed at a separate workplace);
* the process of sintering a multilayer substrate with elements of printing design and a magnetic stripe. It is produced on a special multi-storey press while maintaining a set temperature and pressure controlled by a microprocessor system with subsequent cooling of the package. While one batch of sheets undergoes hot processing, the other is cooled. Such an organization of the technological process ensures the continuity of production;
* feeding of finished sheets with magnetic strips to the cutting machine. After preliminary cutting of the sheets into strips, the final cutting of the workpieces with a magnetic strip takes place.
Then the blank with a magnetic stripe, depending on the task, gets to other stages of production — personalization and information reading, recording quality control.

However, the technology of magnetic cards, as is known, has significant drawbacks, which include the ability to read, destroy and overwrite information, by almost any user who has access to the corresponding recording and reading device. For this reason, magnetic stripe cards are not fully suitable for storing confidential information.
Thanks to the intensive development of microelectronics in the early 70s of the last century, when specialists learned how to create microcircuits with information storage functions with the ability to perform arithmetic operations that occupied an area of only a few square millimeters on a single chip, the emergence of microprocessor technology or smart cards became possible.

Technology of production of microprocessor cards (smart cards)

The main component of the microprocessor card is a module – a functionally complete product that allows you to place the chip in a plastic card and further interact with the terminal. The module protects the microcrystal from unwanted external influences, in particular, from moisture getting on it, which may cause it to stop functioning. For a contact smart card, there must be contacts on the module that interact with the terminal device. In the case of a contactless smart card, a bus is laid connecting the module to the inputs of the interface chip, which is embedded in the plastic card along with its other elements.
The basis for mounting a microcrystal. When creating a module, a microcrystal is attached to the base, which is a type of printed circuit board that determines the topology of the module, including the method of mounting the microcrystal and the connection points of its terminals. On the finished smart card, the visible metallized surface of the contact pads is one of the sides of the base.
The topologies used by specific module manufacturers and the topologies of different smart card chips may differ.

At the initial stage of the development of smart card technology, output frames were produced only in the form of plates or strips, from which individual frames could be isolated separately. Currently, the production method is widely used, in which the frames are located on a rolled tape. The perforated tape can be used in the equipment necessary for the automated production of modules. Rolls with output frames are made of flexible foiled polyester fiberglass. The thickness of the copper foil layer is about 30 microns. A contour corresponding to the topology of the module’s contact pads is formed on the tape by etching. Then the contact surface is gilded with a layer thickness of 35 microns, made on a sublayer of nickel applied to the copper surface of the output frame. In some cases, the contact pads are metallized with nickel with a layer thickness of 6 microns.
Attaching a microcrystal. At the next stage, the microcrystal is attached to the output frame. This process is called crystal joining. It consists in gluing the crystals to the place indicated on the output frame. The glue is squeezed out with a syringe onto the surface of the output frame, the chip is placed on top and pressed. The chip, the output frame and the glue are thermofixed.
Installation of a microcrystal. After the chip is glued, it must be attached to the contact pads of the output frame. Currently, two different methods of microcrystal mounting are widely used.
In the first method, the output frames are attached by soldering to a crystal, on the contacts of which solder is applied in a special way. For this purpose, copper beads can be superimposed on the crystal contacts, which are then wrapped in solder.

The second process is called wire installation. A fragment of wire with a thickness of 27 microns is laid from the chip to each of the contact pads. Currently, gold is mainly used as a material for making wire. However, some companies continue to use aluminum or silver. Despite the higher cost, the use of gold has a number of advantages. Gold wire is the most suitable material at a high rate of operation of assembly equipment, as it has high plasticity and does not tear when fed from bobbins. The most significant of them is that gold is not subject to corrosion that occurs when using aluminum wire in combination with a gold lead frame, as well as the fact that aluminum mounting can become brittle in just two to three months, which is unacceptable for smart cards whose service life is at least seven years according to ISO standards.
Sealing. After the wire installation is completed, the module is sealed by coating its reverse side with a polymer to protect it from the external environment.
Formation of a recess in the card. At the next technological stage, the module is connected to the plastic card (Fig. 2). In order to place the module in the plastic card, a recess (cavitation) must be made in its surface in size without violating the requirements of ISO standards for the thickness of the card (it should be 0.76 mm).

The formation of a recess in the card can be performed in several ways:
* by gluing three or four layers of plastic sheet material, usually polyvinyl chloride. Then milling the hole according to the module’s landing size;
* production of cards using the injection molding method, creating recesses according to the specified parameters. In this case, the card is made of ABS plastic or polycarbonate
Implantation of the module. After a recess is made in the plastic base, the module can be mounted into the card on an adhesive film with subsequent thermal fixation under pressure. The bonding process is activated by heating and pressure. The finished card can be tested, programmed and tested, and then used for specific applications.
Another option for implantation of the module is the use of cyanacrylate-based liquid glue. When using this method, the module is pressed into the recess, which ensures the spreading of the adhesive mass, dosed with a dot method, with a thickness of about 20 microns. After that, the glue polymerizes.

Technology of production of contactless microprocessor cards

When forming a multilayer base with elements of printing design, the package contains inserts (microcircuits), usually placed in the middle of the layer. After the sintering process in laminators, the sheets are fed into the cutting presses, where the cutting of blanks with contactless microcircuits takes place. Next comes the personalization process.

Optical memory cards (laser cards)

Optical memory cards have a larger capacity than memory cards, but data can only be written to them once. Such cards use WORM technology (Write Once Read Many), i.e. a single write is a multiple read. The recording and reading of information from such a card is carried out by special equipment using a laser (from where the other name is a laser card). The technology used in card is similar to that used in laser discs. The main advantage of such cards is the ability to store large amounts of information over 4 megabytes. The information carrier on them is an optical tape. Up to 2000 pages of text can be placed on one such card. In addition to text information, graphic, sound, program files, etc. can be stored on an optical card
. The recording (reading) of information is based on optical technology. Multi-level information protection is provided.
The device for data input (output) to a laser card (card reader/writer) is easily connected to a regular personal computer and allows you to work in WORM mode. The information recorded on the card cannot be erased, but it is possible to repeatedly enter data on the media within the available memory capacity.
At the same time, WORM provides permanent storage of the history of recording information on the card and attempts to access data.
Laser cards are designed to store information and create data banks in medical institutions, archives and libraries.
Applications of laser optical cards:
* security services – storing data for biometric identification (signature samples, fingerprints, palm prints). Laser card can use multi-level protection in the form of magnetic codes, barcode, color, thermal printing, etc.;
• medicine storage case histories of patients, x-rays, test results, ECG, ultrasound, doctors ‘ prescriptions, etc.;
• insurance — the storage attributes of the insurance policy, passport data, information about the objects of insurance (property, real estate, car, health, etc.);
* archives and libraries – storage of texts and drawings, etc.;
* storage of data on motor vehicles;
* driver’s license;
• identity card;
* bank cards.
Optical cards have not yet been distributed in banking technologies due to the high cost of both the cards themselves and the reading equipment.

Production technology of blank cards

Lamination method
The lamination method is now used for most of the manufactured plastic cards, which are subject to increased requirements (Fig. 4). During lamination, individual layers of sheet material are formed into a single frame of the card under the influence of high temperatures and pressure.

Powerful hydraulic presses with heating and cooling are used to form multilayer sheets of the basis of cards in the technological chain of their production. The press is controlled by a built-in microprocessor system that sets the formation cycles of each type of product. The design of modern presses provides heating of one foot and cooling of the other. The molding plates of the presses have channels for accelerated water cooling after heating is completed. Such a measure also ensures a continuous technological process.
During the production process, sheets loaded into special cells are fed from tables with rollers into the loading sections of the press, which are alternately brought by a lifting mechanism under the level of the assembly table. Loaded sections of the press are mechanically placed in the heating and pressing unit.

At the end of the heating cycle, the process is repeated: the cooled cells with pressed sheets are alternately pushed out of the press onto the assembly tables. Here, the upper polished metal plates are removed, providing the required smoothness of the surface, and the finished sheets of multilayer plastic are fed to a conveyor for further processing or stored.

Automated cutting and cutting machines . The cutting machine and the punching press are equipped with an optical positioning system of the sheet, which provides individual reconciliation of the location of the printing design with the standard for each card at these stages of the process. This makes it possible to maintain manufacturing accuracy up to ± 0.01 mm at all stages of product creation, regardless of the shrinkage of materials during the layered formation of a multilayer sheet.
The operator puts the printed, hot-formed and quality-tested plastic sheets on the slipboard, and then cuts them to the required size. At the same time, substandard cards are marked. The cut sheets are picked up from the desktop by a vacuum lifting device and installed on the photocells of the cutting machine. The grippers position the sheet using stepper motors controlled by sensors of the print positioning system. After positioning, the sheet is clamped and cut into separate cards, which are automatically fed to the receiving devices along the conveyor.

The finishing cutting press with automatic print positioning is designed for automatic reception from the cutting machine of strips with cards made of PVC, ABS or other materials, with a thickness of 0.4 to 0.8 mm.
The finishing cutting press performs the final cutting of cards in accordance with standard ISO dimensions and allows the production of millions of cards during its guaranteed service life. It provides cropping of cards to obtain a high-quality well-defined edge. Punchers can be designed to work with any sheet formats with a capacity of 30 thousand cards per hour or more.
The cut-down cards are automatically delivered by conveyor to other finishing sites at a pace corresponding to the specified line performance.
Devices for applying holograms allow you to reduce waste of expensive raw materials and foil defects. A typical modern device includes a dual channel for simultaneous stamping of holograms on two cards with a capacity of up to 7,500 cards per hour.
The cards are fed from the dual store into two channels, each of which has an individual sensor for optical image detection and geometric binding of each superimposed hologram.
The devices provide for the possibility of independent reciprocating movement of optical sensors through each channel of the device, which provides the necessary positional accuracy.
After the embossing operation, the knives separate the excess foil from the surface of the card, creating a smooth edge. The finished cards are automatically sent to a special card-turning conveyor that feeds them to the stamping device for signature panels.
The device for stamping signature panels is similar to a hologram device and includes dual channels for their simultaneous superimposition on two cards that have undergone the process of cutting on a finishing stamp. Its capacity is up to 8000 cards per hour.

In the device for stamping signature panels, as in the hologram machine, there are self-leveling heads that are independently controlled and provide exposure to a set temperature necessary for pressing the signature panels to the surface of the card at a given location. Independent temperature controllers with digital readout in the channels of these devices provide precision control of the heating of the heads.
The finished cards are sent to the double store for automatic feeding to the inspection section of the conveyor.
Control and packaging of workpieces. The cards fed by the conveyor to the inspection collector are sent under the control head, where both sides of them are fully checked at the same time. At the same time, the following parameters are controlled:
* correct positioning of the printed image relative to the edge of the card;
* color characteristics, shades;
* correct positioning of the magnetic strip;
* correct positioning of the hologram;
* correct positioning of the signature panel;
* microcracks, scratches.
The cards that have passed the electronic inspection are dumped onto the conveyor for visual inspection for the detection of defects in layer-by-layer molding or the presence of dust, as well as defects that cannot be detected by this electronic monitoring device.
An automatic packaging device is installed at the end of the line, which receives cards that have passed the inspection section of the conveyor. The device counts the required number of cards to be placed in boxes, which are wrapped with shrink wrap after closing.

Injection Molding method

Injection molding is mainly used in the manufacture of electronic telephone, as well as SIM cards for mobile phones. Recently, contactless microprocessor-based plastic cards have been produced using this technology. With this method of making cards, a polygraphic image is applied to each card separately, and then they are covered with varnish, which serves as a protective film instead of laminate. The recess for implantation of the chip module is formed by a mold. Granulated acrylonitrile butadiene styrene (ABS) is used as raw material. The pellets are fed into the hopper, and then enter the heating zone. The molten mass is injected in portions under high pressure into a mold, usually designed for the manufacture of several blanks. One of the problems that has to be solved when issuing cards by injection molding is the removal of debris formed when the finished card blanks are removed from the molds.

Materials for making cards

Currently, polyvinyl chloride (PVC) remains the most commonly used material for the manufacture of cards. It is easy to process and is quite resistant to temperature conditions in which the cards are used. Credit cards all over the world are made exclusively of PVC.

Polyvinyl chloride, used as the basis of cards, can be painted in various colors. It is neutral in color — this is especially favorable in the manufacture of color printing, the colors of which are not distorted, and the white color remains pure.
Due to the presence of chlorine in the composition of polyvinyl chloride, it is classified as environmentally harmful substances, and the starting material – vinyl chloride – is a carcinogenic substance. However, polyvinyl chloride can be used again and for this reason does not pollute the environment.

PVC is used especially often in the manufacture of cards by lamination. It is not used in the technology of manufacturing cards by injection molding.
Acrylonitrile butadiene styrene (ABS) is an amorphous thermoplastic as well as PVC. It is distinguished by high strength and heat resistance. ABS has very limited possibilities when painting the inner layer and laminate. No negative impact on the environment was detected in ABS. The starting material benzene used for its manufacture belongs to carcinogenic substances.
Currently, ABS is used to make SIM cards for mobile phones, medical insurance cards.
In the field of packaging materials, polyethylene terephthalate (PET), known as polyester, is traditionally used. PET is a thermoplastic that is used in the production of only such cards, for which their harmlessness to the environment is important, and strict requirements for heat resistance are not imposed. In addition, it must be borne in mind that the PET material has very limited possibilities when painting. The negative impact on health and the environment of the PET material has not been revealed. Recycling for reuse of industrial waste obtained during the manufacture of plastic cards, as well as used plastic cards, is associated with high costs due to the fact that they are covered with printing ink. PET is used in lamination and injection molding technologies.

In addition to the materials already mentioned, polycarbonate (PC) is used for the manufacture of plastic cards, which is resistant to high temperatures. PC is used primarily for the manufacture of high-quality cards. The PC lends itself well to painting, but cannot be recycled and reused.
A mixture of PVC and PC is used by some card manufacturers for heat-resistant SIM cards of mobile phones. This card, however, cannot be compared to a card made exclusively from a PC. The use of a mixture of PC and PVC for the production of cards has purely economic rather than environmental reasons, since PC cards are expensive, and their production is quite difficult.
PC can be used in lamination and injection molding technologies.

Blank design

Blank design is a topic that deserves special attention. This is to some extent art on a piece of plastic, if we are talking about good design. If we talk about technical performance, then the programs used to develop the design of the card are similar to programs for the development of ordinary (magazines, catalogs, brochures, brochures) printing products. But everything else is an individual, personal approach of the designer to the product. It is the art of embodying a good design on a small card platform that is the key to the success of a particular product, brand. In addition to strictly arranged elements on the card (such as a magnetic stripe, chip, signature panel) according to ISO international standards, the problem also lies in the embodiment of a highly artistic design or idea on the card, so that it is perceived by the consumer with admiration. After all, the card can be used not only functionally, but also as a collectible, gift or exchange item. To implement the design idea, painting, folk art, construction and photography technologies are often used. Along with this, knowledge is needed in the applied paints to be laminated and protective technologies in printing (guilloche, microshrift, invisible paints, etc.).