Process for producing cooling device for printed circuit card

• US 4,718,163 A
• Filed: 06/30/1986
• Issued: 01/12/1988
• Est. Priority Date: 12/31/1981
• Status: Expired due to Fees

• Current Assignee: Thomson-CSF
• Original Assignee: Thomson-CSF
• Inventors: Berland, Robert, Dumont, Bernard
• Primary Examiner(s): Goldberg, Howard N.
• Assistant Examiner(s): Arbes, Carl J.
• Application Number:
  US06/880,100
• Time in Patent Office: 561 Days
• Field of Search: 361/412, 361/415, 361/382, 361/383, 361/384-388, 174/16 HS, 174/15 HP, 357/81, 357/82, 165/104.33, 165/170, 29/830, 29/840, 29/832, 29/837
• US Class Current: 29/837
• CPC Class Codes: H05K 1/0203 Cooling of mounted components H05K1/0272 takes precedence
• CPC Class Codes: H05K 1/0272 Adaptations for fluid transport, e.g. channels, holes
• CPC Class Codes: H05K 7/20163 the components being isolated from air flow, e.g. hollow heat sinks, wind tunnels or funnels
• CPC Class Codes: H05K 7/20254 Cold plates transferring heat from heat source to coolant
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49139 by inserting component lead or terminal into base aperture
• CPC Class Codes: Y10T 29/49144 by metal fusion

Abstract

The invention relates to a cooling device for a printed circuit card and to its production process.

It is constituted by a parallelepipedic copper frame, to one face of which is fixed the card. The frame is open on two opposite lateral faces orthogonal to the first face.

Copper partitions, orthogonal to the first face, define passages through which the liquid or gaseous cooling fluid flows. Gaps can be made orthogonally to the first face for the passage of the fastening clips of the components.

Application to printed circuit cards equipping airborne equipment.

Claims

1. A process for producing a cooling device for a printed circuit card, successively comprising the following steps:

moulding a material with a melting point well below that of copper to form a core having lateral faces, an upper face and a lower face;

applying a copper coating to the entire surface of said core by electroforming;

machining two lateral faces of said copper coated core so as to remove copper;

dissolving the core and forming a hollow copper frame wherein in said frame a cooling fluid is able to flow;

fixing a printed circuit card to be cooled to a surface of said frame and deposited onto said upper face or said lower face of said core, the face of said card carrying a printed circuit, said face carrying said printed circuit being turned outwards.

2. A process according to claim 16, wherein before the electroforming step, gaps are made through said core from said upper face to said lower face, covering the lateral walls of said gaps with copper during said electroforming step, said gaps each being so that a tight channel is available, after the dissolving step, between the upper surface of the frame deposited onto said upper face of the core and the lower surface of the frame deposited onto said lower face of the core.

3. A process for producing a cooling device for a printed circuit card, wherein said process comprises the following successive steps:

moulding a parallelepipedic core, said core having four lateral faces and two upper and lower faces, said core being made from a material having a melting point well below that of copper,

applying a copper coating to the entire surface of said core by electroforming,

machining a pair of two opposite lateral faces,

dissolving the core,

fixing the printed circuit card to be cooled to an upper or lower face, the face carrying the printed circuit being turned outwards; and

installing the components on the card.

4. A process according to claim 3, wherein a plurality of copper partitions perpendicular to the upper and lower faces are incorporated into said core prior to said electroforming step.

5. A process according to claim 3, wherein gaps are made through said core during the moulding phase, said gaps being orthogonal to the upper and lower faces of said core, said gaps having lateral walls said lateral walls being covered with copper during the electroforming phase, said gaps being made in said core prior to said electroforming step.

6. A process according to claim 3, wherein before said electroforming step, a plurality of copper partitions perpendicular to said upper and lower faces of said core are incorporated into the core.

7. A process for producing a printed circuit card with a cooling device comprising the following steps:

moulding a material with a melting point well below that of copper to form a core having lateral faces, an upper face and a lower face;

applying a copper coating to the entire surface of the core by electroforming;

machining two lateral faces of said copper coated core so as to remove copper;

dissolving the core whereby a hollow copper frame is obtained wherein in said frame a cooling fluid is able to flow;

fixing a first printed circuit card to be cooled onto the surface of said frame and deposited onto said upper face of said core, the face of said first card carrying the printed circuit being turned outwards;

fixing a second printed circuit card to be cooled onto the surface of said frame and deposited onto said lower face of said core, the face of said second card carrying the printed circuit being turned outwards; and

connecting flat packaging components to said first and second printed circuits.

8. A process for producing a printed circuit card with a cooling device comprising the following steps:

moulding a material with a melting point well below that of copper to form a core having lateral faces, an upper face and a lower face;

providing gaps through said core from said upper face to said lower face, said gaps having walls;

applying a copper coating to the entire surface of the core and to the walls of said gaps by electroforming;

machining two lateral faces of said copper coated core so as to remove copper;

dissolving the core so as to leave a hollow copper frame wherein a cooling fluid is able to flow and gaps wherein the cooling fluid cannot flow, said frame having first and second surfaces;

fixing a printed circuit card to a first surface of said frame and deposited onto said upper face or said lower face of said core, the face of said card carrying the printed circuit being turned outwards;

positioning DIL packaging components having leads on a second surface of said frame and deposited onto said upper face or said lower face of said core which is not connected to said printed circuit card, said leads each passing through said frame within one of said gaps and being connected to said card.