This is the Part two of a four-parts essay on Smart Card Manufacturing:
2 – Card Body Production
The customer provide the card artwork (or a draft of it) to the card producer.
The Pre Press department check the customer artwork and optimize it in order to be compliant with the printing tecnique choseen for the specific card to be produced. Final artwork is sent back to customer for final approval.
The customer check the final artwork design and provides the go ahead (or request for modification) to the card producer.
CTP Plate Making
When the customer provide the final approval of the artwork, the Pre Press Department produces the printing plates. Among the several tecnique available, the most used in the industry is called Computer-To-Plate (CTP) and allow a computer graphic image file to output to a photographic film. The film is later used to make the printing plates. A standard card artwork generate four plates according to CMYK color model, and more are generated for any additional special color such as metallic, UV symbols or elements to be printed with security inks.
The printing plates are mounted into the printing machine and the plastic sheets are being printed with the card background image. There are variety of ways of printing plastic cores, but most common techniques are a combination of Offset/Litho. Relief and metallic elements are often printed with Screen printing. This process is normally performed for the card front artwork and for the card back artwork. At this stage all printed sheets are identical and each of them carry from 40 to 60 cards.
Printed Sheet Inspection
Each printed sheet is going under visual inspection and sheets with print imperfections such color registry error, colors not uniform, colors not matching the artwork specification are discarded and shredded.
The printed plastic sheets, along with the inner layers of the cards are gathered and aligned in a sandwich-like structure. The layers can be of many different types and functions including:
- Outer sheet where the front side of the card artwork is printed
- Outer sheet where the back side of the card artwork is printed
- Transparent overlay foils, to protect the printed sheets from scratching and abrasion, to give glossy finishing
- Plastic core sheets made of PVC, ABS, Teslin or other materials that add required thickness to the card body or can act as optimal base material for following personalization step such as laser engraving.
- Magnetic stripe foil
- Foils containing contactless antennas and chips
- Security foils containing holograms or other security elements.
- Inlay containing electronic components such as battery, led, lcd display, buttons, fingerprint sensors or buzzers.
The most common composition are four and five layer cards, for contactless and ID cards even up to nine layers are put together. No matter how many layers are used, as the physical parameters of a card are defined by ISO/IEC 7810 Identification cards – Physical characteristic, the sum of the foil thickness has to be 0.76mm ( ± 0.08mm). Cards embedding electronics such as batteries, LCD displays, buttons or fingerprint sensors are usually a thicker than the specified 0.76mm.
Before entering the lamination press the layers have to be collated in such a way that the images for front and back side match exactly and the location of additional elements, such as magnetic stripes, holographic elements or contactless inlays, is within given tolerances. Semi-automatic or fully automatic machines are utilized to perform such production step.
The pre-mounted sheets are stacked together with thin, highly polished metal plates and loaded into a lamination machine where several heating plates press them for a certain time under certain pressure. Temperature and press time are set according to material used and specific requirement of the final card body. At the end of the process the press plates are lifted and the sheets left to cool down. Each laminated sheet allow to produce a variable number of cards; 24 and 48 cards per sheets are the most popular formats nowadays.
The metal plates used for the lamination process are known as “Lamination Plates”. Those thin sheets of stainless sheet can have various thickness ranging from 0,6mm up to 1mm and their surface can contain elements that gives the cards security and aesthetics features.
Some of the security / aesthetics / functional elements that can be incorporated into a lamination plate includes:
- CMI/CLI Lenses
- Motion Lenses
- 3D Lenses
- Micro lettering
- Latent Images
- Braille lettering
After the sheets reach environment temperature they are loaded into a striping machine that is basically a guillotine creating stripes, each with a single row of cards.
Card Body Punching
The stripes are loaded into a card punching machine that by means of pneumatic tools cutting out the shape of the card. The cards are then stacked for following process steps. The remaining part of the card is waste and sometime is shredded and sold to recycled plastic making companies.
From this stage onward, all processes are performed at card-level.
Sim Plug-in Punching
When the card under production is a Sim Card the plug-in is punched using a metallic tool.
This process is not executed for molded Sim card, because the production process creates the card with the plug-in already.
The cavity that will host the module is created by means of a Milling Machine. The dimension of the cavities varies according to the size of the module to be implanted. If the card host an antenna normally the Milling Machine can reveal the two ends of the antenna. A vacuum suction station is normally used to remove the plastic debris from the milling area.
When a SIM Card has to be produced, several companies make the whole card body, complete already with the module cavity and the SIM pre-cut and, by injecting granular ABS or PLA into a mold. This process, applicable only to cards that do not carry any antenna, does reduce substantially the production cost allowing the SIM Card to be proposed in the market at competitive prices.
Chip Module Testing
The reels dispatched from the silicon manufacturer are going trough electrical test to make sure they are working properly. Defected chip are marked or mechanically punched.
Chip Module Pre-Perso
The modules are loaded with additional Card Operating Systems parameters and applications, applications keys, applets and sometime with software patches. During the process the machine detect and skip the faulty marked chips. Before rolling them in the output reel, the modules are counted.
Glue Tape Laminating
A glue tape is laminated onto the backside of the module tape. To accommodate the chip, holes are punched into the glue tape prior to the lamination. For cards with antennas, two additional holes are created.
Chip Module Punching
The chips are punched and separated from the carrier tape.
Chip Module Implanting
The chip is implanted into the cavity of the plastic card body.
A visual inspection system checks the smart cards for imperfection and reject those with imperfection such as module raised above the card surface, wrong module implanting, visible glue tape, etc.
Some cards are sampled and further manual or automated checks are performed on magnetic stripe position, chip contacts position, card dimensions, card thickness, card bending, card torsion, card abrasion and more.
A security hologram patch is applied on front or on the back of the card. This security element is popular for financial and ID cards. This process step also allow to hot stamp a signature panel and/or a magnetic stripe, normally on the back side of the card.
The hot-stamping technique works with prefabricated elements that are transferred from a carrier tape to the card body using a heated stamp. The elements – such as signature panels – are covered with an adhesive which activates under heat and pressure. Under the hot stamp the element will bond to the card surface and in turn lose its connection to the carrier tape.
Carton Box Packaging
The cards are counted and then automatically packed into cardboard box.
In this step a production operator sample and check few cards from the box for audit purpose.
When the boxes need to be shipped to an external card personalization facility, the boxes are individually sealed with tamper-evident security tape.
Store in Secure Vault
The boxes are stored in the vault that often is a room with single or double security door. The access to the vault is regulated and only authorized production operators are allowed to enter to fetch the cards needed for the personalization.
When the cards ends the card body manufacturing process they have the card front and back personalized with customer artwork but the chip modules does all have same data except for some global information such as chip serial number, COS version and Application version. The cards are ready for the electrical and graphical personalization that is explained in the next part.
Next part: 3- Card Personalization.
The process diagrams are available in a print-friendly PDF file here.