Method for manufacturing a tamper-proof cap for an electronic module

• US 7,788,801 B2
• Filed: 07/27/2006
• Issued: 09/07/2010
• Est. Priority Date: 07/27/2005
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Oggioni, Stefano Sergio, Hadzic, Nihad, Condorelli, Vincenzo
• Primary Examiner(s): Banks; Derris H
• Assistant Examiner(s): NGUYEN, TAI V
• Application Number:
  US11/460,329
• Publication Number:
  US 20070038865A1
• Time in Patent Office: 1,503 Days
• Field of Search: 298/52, 297/39, 298/30, 298/31, 298/32, 298/56, 298/57, 298/58, 361/262, 361/266, 361/648, 361/657, 361/672, 174/262, 174/263, 174/265, 174/251, 174/252, 257/690, 257/691, 438/106, 173/178, 173/176
• US Class Current: 29/852
• CPC Class Codes: G06F 21/87 by means of encapsulation, e.g. for integrated circuits
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 23/576 using active circuits
• CPC Class Codes: H01L 2924/15156 Side view
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H05K 1/0275 Security details, e.g. tampering prevention or detection
• CPC Class Codes: H05K 1/141 One or more single auxiliary printed circuits mounted on a main printed circuit, e.g. modules, adapters H05K1/142 and H05K1/147 take precedence
• CPC Class Codes: H05K 2201/0715 provided by an outer layer of PCB
• CPC Class Codes: H05K 2201/10151 Sensor
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base
• CPC Class Codes: Y10T 29/49172 by molding of insulating material
• CPC Class Codes: Y10T 29/49174 Assembling terminal to elongated conductor

Abstract

A tamper-proof cap adapted to be mounted on a large assembly for shielding a selected area of the large assembly is disclosed. The tamper-proof cap comprises a laminate stack-up structure wherein at least one open chamber is formed. The stack-up structure comprises at least two layers wherein tamper-proof layers are formed on top of the open chamber. A plurality of vias are disposed around the open chamber, forming with said tamper proof layers a tamper-proof structure around said open chamber. The vias are adapted for connecting the tamper-proof layers to the large assembly when the tamper-proof cap is mounted. In a preferred embodiment, the tamper-proof cap further comprises a shielding layer on top of the tamper-proof layer that are preferably done using conductive ink.

Claims

1. A method for manufacturing a tamper-proof cap from a printed circuit board, said method comprising the steps of:

forming a plurality of conductive tracks in at least two stacked conductive layers on a first side of said printed circuit board, said at least two conductive layers being insulated each other with dielectric material;

forming conductive holes in said printed circuit board for providing electrical connection to said plurality of conductive tracks from the second side of said printed circuit board layers stack, said conductive holes and said plurality of conductive tracks forming a tamper-proof layer, whereby one of a short circuit between the conductive tracks and an open circuit in one of the conductive tracks can be detected; and

forming a cavity in said second side of said printed circuit board, said cavity being surrounded by said conductive tracks and said conductive holes.

2. The method of claim 1 further comprising forming metal pads connected to said conductive holes.

3. The method of claim 1 wherein said conductive tracks are formed with conductive ink or metal oxides.

4. The method of claim 1 further comprising the steps of:

depositing a dielectric material on top of said at least two conductive layers; and

forming a conductive layer on top of said deposited dielectric material.

5. The method of claim 1 further comprising the step of

forming a conductive surface on said printed circuit board, between said printed circuit board and said at least two conductive layers, said conductive surface being insulated from said at least two conductive layers, to form an electromagnetic shield.