US-12628272-B2 - Integrated circuit optical package comprising a flexible electrical connection element

Abstract

An integrated-circuit package includes a flexible electrical-connection element sandwiched between a first face of a first multilayer support substrate and a second face of a second multilayer support substrate. The flexible electrical-connection element laterally projects with respect to, and is in electrical contact with at least one of, the multilayer support substrates. The flexible electrical-connection element and the first multilayer support substrate include, at a first region, respectively two first mutually facing orifices defining together a first cavity. The first cavity is at least partially closed off by a first part of the second face of the second multilayer support substrate. A first component is located in the first cavity, attached at the first part of the second face of the second multilayer support substrate and in electrical contact with the flexible electrical-connection element through the second multilayer support substrate.

Inventors

• Romain Coffy
• Younes BOUTALEB

Assignees

• STMICROELECTRONICS (GRENOBLE 2) SAS

Dates

Publication Date

20260512

Application Date

20230605

Priority Date

20220608

Claims (20)

1. 1 . An integrated-circuit package, comprising: a first multilayer support substrate; a second multilayer support substrate; a flexible electrical-connection element sandwiched between a first face of the first multilayer support substrate and a second face of the second multilayer support substrate; the flexible electrical-connection element including a portion laterally projecting with respect to the first and second multilayer support substrates; the flexible electrical-connection element in electrical contact with at least one of the first and second multilayer support substrates; the flexible electrical-connection element and the first multilayer support substrate including, in a first region, respectively two first mutually facing orifices defining together a first cavity at least partially closed off by a first part of the second face of the second multilayer support substrate; and a first component located in said first cavity, attached on said first part of the second face of the second multilayer substrate and in electrical contact with the flexible electrical-connection element by way of the second multilayer support substrate.
2. 2 . The package according to claim 1 , wherein the flexible electrical-connection element comprises at least one electrically conductive layer within an electrically insulating layer, wherein each multilayer support substrate comprises at least one electrically conductive layer within an electrically insulating layer, and wherein at least one of the first and second multilayer support substrates locally comprises, outside said first cavity, at least one electrically conductive pillar having a first end contacting said at least one electrically conductive layer of said at least one of the first and second multilayer support substrates and having a second end in local electrical coupling with said at least one electrically conductive layer of the flexible electrical-connection element.
3. 3 . The package according to claim 1 , wherein the flexible electrical-connection element comprises one or more electrically conductive layers within an electrically insulating layer, wherein each multilayer support substrate comprises at least one electrically conductive layer within an electrically insulating layer, and wherein each of the first and second multilayer support substrates locally comprises, outside said first cavity, at least one electrically conductive pillar having a first end contacting said at least one electrically conductive layer of the corresponding first and second multilayer support substrate and having a second end in local electrical coupling with the electrically conductive layer or layers of the flexible electrical-connection element.
4. 4 . The package according to claim 1 , further comprising an electrically insulating filler layer between each of the first and second multilayer support substrates and the flexible electrical-connection element.
5. 5 . The package according to claim 1 , wherein the first component comprises an electronic integrated circuit chip.
6. 6 . The package according to claim 1 , wherein the second multilayer support substrate includes, in said first region, a first through orifice having a first end emerging in said first cavity facing the first component.
7. 7 . The package according to claim 6 , wherein the first component includes a first optical device in optical coupling with the first end of the first through orifice.
8. 8 . The package according to claim 7 , comprising a first optically transparent element closing off a second end of the first through orifice.
9. 9 . The package according to claim 1 , further including, at said first region, a first cap resting on the second multilayer support substrate and defining a first housing above said first cavity.
10. 10 . The package according to claim 9 , wherein the second multilayer support substrate includes, in said first region, a first through orifice having a first end emerging in said first cavity facing the first component, and wherein the first cap has a first opening facing the first through orifice.
11. 11 . The package according to claim 10 , wherein the first component includes a first optical device in optical coupling with the first end of the first through orifice, and further including at least one first auxiliary optical element in said first housing in optical coupling with said first opening and with the first optical device.
12. 12 . The package according to claim 1 , wherein the flexible electrical-connection element and the first multilayer support substrate include, in a second region of the package, respectively two second mutually facing orifices defining together a second cavity partially closed off by a second part of the second face of the second substrate, and the second multilayer support substrate includes, in said second region, a second through orifice emerging in said second cavity, the package further including: a second component located in said second cavity, attached to said second part of the second face of the second multilayer support substrate; and a second optical device located above the second component and at least partially in the second through orifice.
13. 13 . The package according to claim 12 , wherein the second optical device is in electrical contact through connecting wires with contact pads located on the first face of the second multilayer support substrate.
14. 14 . The package according to claim 12 , further including, at said second region, a second cap resting on the second multilayer support substrate and defining a second housing above said second cavity, the second cap including a second opening facing the second through orifice, the package further including at least one second auxiliary optical element in said second housing in optical coupling with said second opening and with the second optical device.
15. 15 . The package according to claim 1 , wherein the first multilayer support substrate includes a second face opposite to the first face, wherein each component attached to the first multilayer support substrate includes a rear face opposite to the one attached to the second multilayer support substrate, and the package further including a heat dissipator in contact with the second face of the first multilayer support substrate and with the rear face of each component using a thermally conductive material.
16. 16 . The package according to claim 1 , wherein the portion of the flexible electrical-connection element laterally projecting with respect to the first and second multilayer support substrates is configured for making an electrical connection between elements of the package and a printed card that is offset with respect to the package.
17. 17 . An integrated-circuit package, comprising: a first multilayer support substrate; a second multilayer support substrate; a flexible electrical-connection element sandwiched between a first face of the first multilayer support substrate and a second face of the second multilayer support substrate; wherein the flexible electrical-connection element includes a first orifice; wherein the first multilayer support includes a second orifice; wherein the first and second orifices face each other and together define a cavity; a component located in said cavity; wherein a first part of the second multilayer support substrate extends at least partially over the cavity and includes a first metal pillar at the second face of the second multilayer support substrate that is electrically connected to the component; wherein a second part of the second multilayer support substrate includes a second metal pillar at the second face of the second multilayer support substrate that is electrically connected to the flexible electrical-connection element; and wherein the second multilayer support substrate further includes an electrically conductive layer electrically connecting between the first and second metal pillars.
18. 18 . The package according to claim 17 , wherein the component comprises an electronic integrated circuit chip.
19. 19 . The package according to claim 18 , wherein the second multilayer support substrate includes, in said first region, a through orifice having a first end emerging in said cavity facing the electronic integrated circuit chip.
20. 20 . The package according to claim 19 , wherein the electronic integrated circuit chip includes a first optical device in optical coupling with the first end of the through orifice.

Description

PRIORITY CLAIM This application claims the priority benefit of French Application for Patent No. 2205475, filed on Jun. 8, 2022, the content of which is hereby incorporated by reference in its entirety to the maximum extent allowable by law. TECHNICAL FIELD Embodiments and implementations relate to the field of microelectronics, in particular the field of packaging of integrated circuits and more particularly integrated-circuit packages, for example integrated-circuit optical packages, intended to be offset with respect to a printed circuit card and electrically connected thereto by a flexible connector, also known to a person skilled in the art as a “flex”. BACKGROUND Such a flexible connection element, or connector, is well known to a person skilled in the art and generally comprises a web of metal tracks on one or more levels, mutually electrically insulated by an insulating resin and intended to route electrical signals. A person skilled in the art can optionally refer to an article on such flexible connectors, entitled “Flexible electronics” available on the internet. The structure of such a connector (in particular its very low thickness) confers great flexibility thereon, thus making it possible to twist it greatly, optionally with angles that may range up to 180°. It moreover proves necessary, for certain types of package, such as optical packages (i.e., those comprising at least one optical device), to provide support substrates including cavities for housing this optical device or devices therein. Currently, support substrates made from ceramic are used, allowing easy production of cavities. However, such support substrates are expensive and it is necessary to provide the passage for the “flex” connector intended to connect the optical device to a printed circuit card offset with respect to the package, which can make producing the package complex. There is consequently a need to produce integrated-circuit packages, in particular optical packages, having less expensive carrier substrates that are simpler to produce while allowing an easy formation of cavities and an offset electrical connection. SUMMARY According to one embodiment, it is proposed to use, as carrier substrate for the package, an assembly including a flexible connector of the “flex” type sandwiched between two multilayer carrier substrates. In this way it is easy to produce cavities in this assembly, so as to house a component therein, for example an electronic integrated circuit chip, while allowing an offset electrical connection of the package by means of a projecting part of the flexible connector. According to one aspect, an integrated-circuit package is proposed, comprising a flexible electrical-connection element sandwiched between a first face of a first multilayer support substrate, typically the bottom support substrate, and a second face of a second multilayer support substrate, typically the top support substrate. The flexible connection element projects laterally with respect to the two multilayer support substrates and is in electrical contact with at least one of the two multilayer support substrates and optionally both multilayer support substrates. The flexible connection element and the first multilayer support substrate include, in a first region of the package, respectively two first mutually facing orifices, defining together a first cavity at least partly closed off by a first part of the second face, typically the bottom face, of the second carrier substrate. In some cases this first cavity may be completely closed off by the second face of the second carrier substrate. A first component is located in said first cavity and is attached (directly or indirectly) to said first part of the second face of the second substrate and in electrical contact with the flexible connection element by means of the second multilayer support substrate. According to one embodiment, the flexible connection element comprises at least one electrically conductive layer enrobed in an electrically insulating layer and each multilayer support substrate comprises at least one electrically conductive layer enrobed in an electrically insulating layer. At least one of the two multilayer support substrates comprises locally, outside said first cavity, at least one electrically conductive pillar having a first end contacting said at least one electrically conductive layer of this multilayer support substrate and having a second end in local electrical coupling with said at least one electrically conductive layer of the flexible connection element. In this embodiment, the two multilayer support substrates may not both be electrically connected to the flexible connector. This being the case, in another possible embodiment, they may both be electrically connected to the flexible connector. Thus, according to this other embodiment, the flexible connection element may comprise one or more electrically conductive layers, each enrobed in an electric