GB2305395A - Security marker for PCB with security code - Google Patents

Abstract

The marker 8 has a security code either i) printed, etched or lase cut thereon or ii) in the form of a non-reprogrammable laser etched chip 11 which can be read remotely by means of an RF field. The marker 8 comprises an elongate member having a channel 9 for attachment by adhesive 12 to the edge 5 of the PCB or SIMM 1.

Description

This invention relates to a security marker for PCBs, particularly for single in :me memory modules (hereinafter referred to as SIMMs).

Printed circuit boards, particularly SIMMs. included in computer hardware are proving vulnerable to theft. SIMMS, above all, are relatively valuable small imits, loosely fixed inside the hardware (being intended to be readily replaceable) md are proving relatively easy to steal.

Some PCBs are now being manufactured with an internal code programmed into me circuitry. However, this does not apply to all PCBs which are installed in computers and the stolen PCB would also have to be inserted into a .computer system to identify the code.

x code which can be read by eye or with a simple, portable device is required.

By marking a printed circuit board with a distinctive security code which can, for sample, be checked against a central record relating codes to registered owners, me tracing and identification of stolen PCBs can be much enhanced, thereby educing the value of PCBs as stolen goods.

In the first aspect, the present invention provides a marker for marking a printed .ircuit board, the marker having a security code thereon. The security code is risible and allows the bar to be identified. PCBs may be marked with a printed zIpha-numeric code or bar code, for example.

The inventor of the present invention has discovered that a remotely readable zde carrying device which is read by a field or signal can be contained in a protective rigid member which is adhered to the PCB and, contrary to pectation, the code carrying device can still be read through the PCB and protective member.

x member which is strong enough to protect the code carrying device from umpiring and the conductive copper coating which covers most of the surface of r PCB would be expected to attenuate a field or signal sent by a reading device to c code carrying device, but it is surprisingly found that the device is still readable.

h a second aspect, the present invention provides a security marker for marking a printed circuit board, the marker comprising a rigid protective member having at least one face for contact with and adhesion to the printed circuit board, and a remotely readable code carrying device received in a recess in the contact face.

e order to protect the code carrying device the rigid protective member should have sufficient properties of strength, stiffness and toughness to resist the tools commonly available to sieves, such as knives, chisels, hammers. hand held power drills, files, hachaws, etc. The security marker (or rigid protective member which forms pat of the security marker) may be made of metal such as iron, steel or brass. It is preferred that the security marker has the toughness at least of soft iron, preferably of brass. However, it is preferred to use a nonconductive material for sample a synthetic polymeric material, to avoid problems with short cirtiiting the conductors on the PCB.The security marker (or rigid protective merber) may be formed by machining, extrusion or any other suitable method.

Composite synthetic niwials are particularly preferred, such as glass reinforced nylon or composites used to make bulletproof clothing. They ma be reinforced with glass or metal shees or wires.

Preferably, the rigid protective member is larger than the code carrying device in area. For example, it cculd be four, preferably at least six or ten times the area of the code carrying device If the rigid protective member is then made opaque, it will not be apparent to ne thief where the code carrying device is located. If the thief attempts to destroy the code carrying device by cutting through the rigid protective member, the Thief may have to make several attempts before the code carrying device is reached.

Preferably, the position Df the code carrying device within the rigid protective member is substantiall! -andom along a given axis or along two axes at right angles.

The security member miy have a case hardened or armoured surface.

It is recognised that all :rms of security marker will be vulnerable to destruction by a sufficiently powerful tool. However, the security marker should be designed so that it will resist any Idols except tools which are bulky, expensive or difficult to operate. Further, the security member should be designed so that any tool which can penetrate the rigid protective member will take considerable time and care thereby much redu mg the ease with which a stolen PCB can be sold by a thief.

The security marker mq; be adhered to the surface of the PCB using adhesives such as epoxy resin. The efficiency of bond achieved by a suitable adhesive may be such that it is almost impossible to remove the security marker from the surface of the PCB without damaging the PCB itself and ruining its value.

The security marker of3e second aspect in the invention may have a security code thereon, as in the rrst aspect of the invention.

Preferab:-, the security marker of either aspect of the invention is adhered to the PCB in s 1ch a manner that removal of the security marker by force would damage ine PCB. PCBs such as SIMMs are commonly designed in a generally rectanguFar form with integrated circuit devices on one surface or both surfaces, and a bosom edge having a plurality of contacts to allow the integrated circuit devices be connected into the rest of the hardware. Two short edges adjacent the edge with the contacts are provided with means such as holes or recesses for fixing the PCB n position in a suitable structure in the computer. When in position, there is a single substantially linear free edge which is exposed.

Frequently, this free edge is the only edge which is free of equipment such as connectas or fixing means which are central to the design of the PCB. Further, the free edge is frequently the only edge which is visible and accessible when the PCB is it position.

According to a preferred embodiment, the security marker comprises a substantAlly linearly extending rigid member for engaging the substantilly linearly extending free edge of a PCB.

This allows the security marker to be fitted onto a PCB in situ in a computer without asturbing any of the connections or fixing means. It also allows the security marker to be positioned so that it is readily accessible for checking when the PCB in position in a computer. For example, it may be necessary to check that a computer has not been provided with stolen PCBs. Alternatively, the owner of the computer may wish to check that the PCBs with which it was originally installed have not been replaced by dummy or low grade limitations.

In each case, it is preferable not to move the PCBs from position, as this can damage veir contacts and it is time consuming. By attaching the security marker to the free edge, the security marker can be fitted and checked without removing the PCB from the computer.

In a preferred embodiment, the security marker / ngid protective member comprised a linearly extending bar having a slot extending along a face, the slot being suh-tantially equal to or wider than the thickness of a PCB. A recess for containing a code carrying device may be formed in the base of the slot. The slot may be closed at the ends or it may extend to the small faces of the security marker, This amngement allows the security marker to form a particularly strong bond to the free edge of the PCB, making it extremely difficult to remove the security marker fom the PCB without destroying the PCB The width of the slot is preferably slightly greater than the thickness of the PCB, to allow for the thickness of the adhesive layer between the PCB and the security marker, Grip parts may be provided for extending the contact area between PCB and security marker.

For a typical SIMM, the securry marker / rigid protective member used in the present invention will be in the region 2 to 15 cm, preferably, 4 to 12 cm in length. It may have a width fTem 2 to 5 mm and a depth of from 2 to 5 mm. A slot of width approximately 1 ' mm may be provided extending along part of the length of the bar.

The code carrying device may be any suitable remotely readable device responding, for example, to electromagnetic waves, for example radio waves, sound waves or a magnetic fidd. Such devices are well known in the art for "tagging" objects so that the objects can be identified with a suitable, known, reading device.

It is particularly preferred that the code carrying device should be nonreprogrammable, for example having a laser cut chip. It may be readable by a magnetic field. The Inventors have found, surprisingly, that a magnetic code carrying device can be interrogated effectively even if the rigid protective device is made of ferrous material.

Normally, a plurality of SIILls are inserted into a PC in sets, side by side, approximately 15 mm apart, stich makes it difficult to mark the faces of the SIMM, because they will not be readable when in position. It is highly preferred that the SIMMs should be readable without moving them from the PC and that the security marker can be fitted to a SIMM that is already in position in a computer.

The code on the security marker may be applied by any suitable means. It must be visible. The code may be printed or cut into the surface. A printed code or a code cut into the surface of the marker (for example laser cut) could be placed at any suitable position on the security marker. Preferably it is placed where it will be easily read when in position on the SIMM in a personal computer. However, it may be placed on any suitabk edge or face.

Care should be taken when placing the security marker on a PCB that metal parts of the security marker do not contact any conductive parts of the PCB, which would create the risk of a shon circuit. The adhesive may form an effective insulator between the security marker and the PCB.

A security marker according to the invention can be installed on a PCB with a relatively simple process of first of all cleaning the appropriate edge of the PCB, applying adhesive to the PCB and/or security marker and holding the security marker and PCB in contact for sufficient time for a suitable bond to be formed.

The present invention will be further described by way of example only with reference to the accompanying drawings, in which: Brief description of drawings Figure 1 is a plan view of a SIMM of a type commonly used, Figure 2 is an isometric drawing of a security marker according to the first aspect of the present invention.

Figure 3 is an isometric drawing of a security marker according to the second aspect of the present invention, inverted to show the inside.

Figure 4 is a cross-sectional view of the security marker of Figure 3 engaged with the SIMM of Figure 1; and Figure 5 shots the security marker being interrogated Figure 1 is a plan view of a SIMM (single in-line memory module) of a type commonly used in the art. It comprises a printed circuit board 2 carrying a number of memory chips 3, circuitry shown schematically at 4 and connections along one edge. Fixing means in the form of holes 6 for engagement witch fixing devices such as clips are provided in the short edges of the SIMM and there is one linearly extending free edge 5. In use, the SIMM is fuzed into a piece of hardware by engagement of screws with the holes. The connections connect with corresponding connections in the hardware and only the free edge 5 is accessible.

Figure 2 is a isometric drawing of a security marker according to the first aspect of the invention. It is suitable for use with the SIMM of Figure 1.

It comprises a glass reinforced nylon channel-shaped bar 6 of length 11.1 cm, depth Smm and width 5mm. A channel 7 of width l.;mm is provided extending along the bar 6. not reaching the ends of the bar. Grips are provided to give a stronger bond when adhered to a SIMM.

The channel 7 is approximately as deep as it is wide. x security code (not shown) may be printed, etched or cut (preferably lazer cut) onto one of the long surfaces of the marker apart from the surface having the channel 7. Preferably, the bar 6 is fixed with the channel 7 extending over the free edge 5 of the SIMM and bonded thereto by, for example, epoxy resin which forms a strong bond. It is then extremely difficult to remove the marker without damaging the SIMM. If the marker is made of sufficiently strong material, it is difficult to remove the code applied thereto. If the code is removed it is likely to leave evidence that the code was once carried. This indicates that the item is stolen. The configuration of the security marker allows it to be adhered to a SAM when the latter is in position in a electronic device.

Figure 3 shows a second tpe of security marker for use with the SIMM of Figure 1. It comprises a glass reinforced nylon channel-shaped bar 8 of length 11.1 cm, depth 5 mm and width 5 mm. A chaznel 9 of width 1.3 mm is provided extending along the bar 8. There is a recessed portion 10 of the channel 9 in which a code carrying device 11 is fixed by means of adhesive. The channel 9 is approximately as deep as it is wide.

The code carrying device 11 comprises a laser etched chip which is not reprogrammable and which accordingly carries one code which cannot be altered.

It comprises windings (not shown) for interaction with a RF field whereby the code in the laser cut chip can be read by a reader which generates a RF.

In order to provide the SIMM 1 with a unique code number which can be used at any time to identify the SIMM and (by referring to a central check list) to confirm who should own the SIMM, a specific security marker having a code carrying device with a unique code is adhered to the SIMM 1 as shown in Figure 4.

Figure 4 shows the bar 8 placed on top of the free edge 5 so that the edges of the channel 9 overlap the SIMM 1. Adhesive 12 shown stippled in Figure 3 is used to secure the bar 8 and code carrying device 11 on the SIMM 1.

The adhesive 12 may be epoxy resin of very high bond efficiency. The code carrying device 11 can therefore be fixed very securely to the SIMM 1 and is protected by the bar 8 and SIMM 1.

The rigid material of the bar 8 makes it difficult to tamper with the code camping device 11 without damaging the Sl f 1.

Figure 5 shows a view of the security marker adhered in place on a SIMM 1. The position of the code carrying device 11 is shown in broken lines, though it would not be visible to anyone inspecting the SIMM.

A top surface 14 of the bar 8 may be provided with a laser cut alpha-numeric code 15, for example, which provides additional security.

The reader may be a RF reader of the type sold under the trade mark AVID.

The present invention has been described above purely by way of example, and modifications can be made within the spirit of the invention. The invention also consists in any individual features described or implicit herein or shown or implict in the drawings or any combination of such features or any generalization of any such features or combination.

Claims (11)

1. A security martyr for marking a printed curcuit board. :he marker having a security code thereon.

2. A security martyr according to Claim 1, comprising a substantially linearly extending rigid member.

3. A security marker for marking a printed circuit board, me marker comprising a rigid protective member having at least one face for contact with and adhesion to the printed circuit board, and a remotely readable code carrying device received in a recess in the contact face.

4. A security marker according to Claim 3, wherein the code carrying device comprises means fDr receiving and transmitting electro-magnetic waves, sound waves or magnetic field signals.

5. A security martyr according to any preceding Claim, comprising composite synthetic material

6. A security martyr according to any preceding Claim, comprising a substantially linearly extending rigid member for engaging a substantially linearly extending =ree edge of a PCB.

7. A security marker according to any preceding Claim, comprising a linearly extending bar hang a slot extending along a face thereof. the width of the slot being substantiall! equal to or wider than the thickness of a PCB.

8. A method of marking a PCB, comprising fixing thereto a security marker having a security code thereon.

9. A method of marking a PCB, comprising adhereing thereto a security marker comprising a rigid protective member having a face for contact and adhesion to the PCB, and a rerotely readable code carrying device received in a recess in the contact face.

10. A method according to Claim 8 or 9, wherein the secrrity marker is adhered to the printed circ=n board.

11. A security maker, substantially as herein described sith reference to Figures 2 or 3 to 5 of the axompanying drawings.