Process for producing electrical connections through a substrate

• US 4,964,212 A
• Filed: 09/08/1989
• Issued: 10/23/1990
• Est. Priority Date: 09/29/1988
• Status: Expired due to Term

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation), Compagnie Europeenne de Composants Electroniques L.C.C.
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation), Compagnie Europeenne de Composants Electroniques L.C.C.
• Inventors: Dupeux, Thierry, Sibuet, Henri, Deroux-Dauphin, Patrice
• Primary Examiner(s): Hall, Carl E.
• Assistant Examiner(s): Arbes, Carl J.
• Application Number:
  US07/404,410
• Time in Patent Office: 410 Days
• Field of Search: 29/852, 204/15, 174/68.5, 437/173, 219/121.68, 219/121.69
• US Class Current: 29/852
• CPC Class Codes: B23K 26/389 of fluid openings, e.g. nozzles, jets laser machining of inkjet nozzles B41J2/1634
• CPC Class Codes: G11B 5/3103 Structure or manufacture of integrated heads or heads mechanically assembled and electrically connected to a support or housing
• CPC Class Codes: H01L 21/76898 formed through a semiconductor substrate
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 2201/0326 Inorganic, non-metallic conductor, e.g. indium-tin oxide [ITO]
• CPC Class Codes: H05K 2201/0394 Conductor crossing over a hole in the substrate or a gap between two separate substrate parts
• CPC Class Codes: H05K 2201/09509 Blind vias, i.e. vias having one side closed
• CPC Class Codes: H05K 2203/0207 Partly drilling through substrate until a controlled depth, e.g. with end-point detection
• CPC Class Codes: H05K 2203/1383 Temporary protective insulating layer
• CPC Class Codes: H05K 3/0029 of inorganic insulating material
• CPC Class Codes: H05K 3/4076 by thin-film techniques
• CPC Class Codes: Y10S 438/94 Laser ablative material removal
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base

Abstract

According to the invention, blind holes (27) and not through-holes are produced. For this purpose, the substrate (10) to be pierced or perforated is previously covered with a layer (12) less absorbing for the laser perforating beam (26) than the substrate.

Application to the production of electronic circuits, magnetic recording devices, etc.

Claims

1. Process for the production of electrical connections through a substrate comprising the steps of:

depositing at least one thin layer (12) of material on the substrate (10), the material of the at least one thin layer (12) being only slightly absorbent of a laser beam (26) such that the laser beam (26) passes through the at least one thin layer (12) without perforating the material to form an emergent beam (28) after passing therethrough;

exposing the substrate (10) with the at least one thin layer (12) material to the laser beam (26), the laser beam (26) being at least partially absorbed by the substrate (10) to drill a hole only in the substrate (10), the laser beam (26) passing through the at least one thin layer (12) of material withous perforation thereof to form a blind hole in the substrate (10) having a bottom formed substantially by the at least one thin layer (12) of material; and

forming electrical connections through the substrate (10) using the hole formed by the laser beam (26).

2. Process according to claim 1, wherein the substrate (10) is at least one conducting and semiconducting and the at least one thin layer of material is (12) insulating.

3. Process according to claim 2, wherein the substrate (10) is of silicon.

4. Process according to claim 2, wherein the at least one thin layer of material (12) is made of silica.

5. Process according to claim 2, wherein following the drilling of the hole (27), an insulating layer (30) is deposited on walls of the hole.

6. Process according to claim 1, wherein substrate (10) is insulating and the at least one thin layer of material is (12) conducting.

7. Process according to claim 6, wherein the conducting layer (12) is of a material chosen from within the group consisting of InSnO, InSn, SnO₂ and In₂ O₃ SnO₂.

8. Process according to claim 6, wherein the conducting layer (12) is etched and serves as a contact means (36).

9. Process according to either of the claims 5 and 6, wherein a conductive material (32) is deposited in at least part of the hole.

10. Process according to claim 8, wherein as the layer is insulating, it is etched right through facing the hole and wherein contacts are produced on said layer.