FR3134679A1 - Process for manufacturing nested electronic modules by additive manufacturing - Google Patents

Abstract

Method for manufacturing nested electronic modules by additive manufacturing Method for manufacturing an electronic circuit (400) comprising: the additive manufacturing of a first electronic card (410) comprising at least on a first face (4101) an electrically conductive connector ( 411, 412) and an electronic component (451) and the additive manufacturing of a second electronic card (420) comprising at least on a first face (4201) an electrically conductive connector (421, 422) and a cavity (442), andthe superposition of the first and second electronic cards so that the first face (4101) of the first card (410) faces the first face (4201) of the second card (420), that the electrically conductive connector (411, 412) of the first card (410) is in electrical contact with the electrically conductive connector (421, 422) of the second card (420) and that the electronic component (451) of the first card (410) ) is placed in the cavity (442) of the second card (420). Figure for abstract: Fig. 4

Description

Process for manufacturing nested electronic modules by additive manufacturing

The present invention relates to the general field of manufacturing by additive printing of electronic circuits, and more particularly to the additive manufacturing of elementary electronic cards and nested electronic modules.

More and more electronic boards are manufactured using additive manufacturing processes, in order to obtain circuits of different shapes, flexible circuits, and/or portable circuits. However, card thicknesses are limited by these processes to a few millimeters (3 mm).

Thus, to circumvent this thickness limitation and to reduce the bulk of the electronic cards in order to meet the needs of integrated electronics, the cards can be stacked on top of each other. Header-type connectors are soldered between the boards to electrically connect the boards together to share a power supply and/or transmit digital or analog signals between them. However, this type of connector is generally bulky and adds additional mass to electronic cards.

Furthermore, these connectors are through components soldered to the card, which are generally placed on the periphery of the cards. This involves routing the tracks accordingly, and this excess routing reduces the integration capacity of the cards, and can also be harmful to the electrical performance of the cards, by creating voltage drops, series resistances, parasitic capacitances, parasitic inductances and/or electromagnetic disturbances.

US patent 10,575,408 proposes an alternative to the use of these through connectors, which consists of connecting two electronic cards together by bringing their conductive tracks into contact. For this, the cards each include an imprint that can fit with the imprint of another card placed opposite and thus ensuring alignment and contact between the conductive tracks of the two cards.

However, the solution proposed in US patent 10,575,408 does not allow mechanical retention between the cards. This mechanical support is ensured through a third-party part: a sort of ring or ring, which adds bulk and mass to the whole. In addition, the electrical contact between the two electronic cards is located at the end of the card. This adds constraints to the routing, and possibly parasitic elements to the electrical signals.

It is therefore desirable to have a method of manufacturing an electronic circuit making it possible to obtain a compact and lightweight electronic circuit in order to improve the integration capacity of the circuit in restricted spaces.

The invention relates to a method of manufacturing an electronic circuit comprising:

• the additive manufacturing of a first electronic card comprising at least on a first face an electrically conductive connector and an electronic component and the additive manufacturing of a second electronic card comprising at least on a first face an electrically conductive connector and a cavity, and
• the superposition of the first and second electronic cards so that the first face of the first card is opposite the first face of the second card, that the electrical conductive connector of the first card is in electrical contact with the electrically conductive connector of the second card, and that the electronic component of the first card is placed in the cavity of the second card.

Thanks to the invention, it is possible to circumvent the card thickness limitation by superimposing at least two electronic cards on top of each other and by electrically connecting them via their additively manufactured connectors.

In addition, to connect the superimposed cards together, the classic connectors of the strip type, pins, or electrical cables are replaced by connectors manufactured in an additive manner which form connection points located as close as possible to the need to optimize the interconnection between the cards. These new connectors make it possible to reduce the size and mass of the electronic circuit formed by the superposition of the two cards, and to limit the number of conductive tracks on the cards dedicated to signal routing.

The cavity present on the first card allows the electronic component to be buried, to optimize and best integrate the component into the electronic circuit.

According to a particular characteristic of the invention, the additive manufacturing of said electrical conductive connectors of the first and second cards is chosen from inkjet printing, printing by fused wire deposition or printing by laser fusion on a powder bed.

According to another particular characteristic of the invention, said electrical conductive connectors of the first and second cards are manufactured from a conductive ink comprising silver nanoparticles and the electronic component of the first card is soldered to the first card by said conductive ink.

According to another particular characteristic of the invention, the first and second electronic cards comprise non-conductive parts made of a photosensitive resin.

According to another particular characteristic of the invention, said electrical conductive connectors are of conical or trapezoidal shape.

According to another particular characteristic of the invention, said electrical conductive connectors are of the single-signal type. This allows connectors to be placed in an optimized manner, that is to say according to the placement between the components present on the cards, without having to gather all the signals in a single connector.

According to another particular characteristic of the invention, said electrical conductive connectors are of the multi-signal type. This makes it possible to transmit at least two signals, for example an antenna signal and a shielded signal, and to limit the number of connectors on the cards.

According to another particular characteristic of the invention, the electrically conductive connector of the first card is of the male type and the electrically conductive connector of the second card is of the female type of complementary shape to the male type connector of the first card.

This ensures good electrical contact between the conductors of the first and second cards.

According to another particular characteristic of the invention, the second card also comprises on a second face at least one electronic component and an electrically conductive connector and the method comprises the additive manufacturing of a third electronic card comprising at least on a first face a electrical conductive connector and a cavity, and the superposition of the third card on the second card so that the first face of the third card is opposite the second face of the second card, that the conductive connector electrical of the third card is in electrical contact with the electrically conductive connector of the second face of the second card and that the electronic component of the second card is placed in the cavity of the third card.

This makes it possible to stack several electronic cards together to form a single electronic circuit that can have a thickness greater than 3 mm. In addition, as for the superposition of two cards, the connection cables are reduced or even eliminated and replaced by electrically conductive connectors, which makes it possible to reduce the mass of the circuit and optimize the placement of connectors and components on each map.

According to another particular characteristic of the invention, the method further comprises putting the superimposed electronic cards under press.

Pressing ensures the mechanical connection of the cards together and ensures electrical cohesion.

Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended drawings which illustrate examples of embodiment devoid of any limiting character.

There represents, schematically and partially, a method of manufacturing an electronic circuit according to one embodiment of the invention.

There represents, schematically, electrical conductive connectors of an electronic circuit manufactured according to one embodiment of the invention.

There represents, schematically and partially, electrical conductive connectors of an electronic circuit manufactured according to another embodiment of the invention.

There represents, schematically and partially, an electronic circuit produced according to one embodiment of the invention.

Throughout the description, for clarity, an electrically conductive connector is referred to as a connector.

There represents, schematically and partially, a method 100 for manufacturing an electronic circuit according to one embodiment of the invention.

The process 100 first comprises the additive manufacturing 110 of electronic cards. During the additive manufacturing of the cards, the electrical conductive connectors present on a first face of each card are also manufactured. During manufacturing, an electronic component is also placed on the first face of one of the cards which is soldered to the card during additive manufacturing and a cavity is also made on the first face of the other card.

Cards and connectors are, for example, manufactured by inkjet printing, fused deposition printing or even laser powder bed fusion printing. The conductive parts of the cards, such as the connectors and/or the conductive tracks, can be made from a conductive ink, for example an ink based on silver, copper or even platinum, for example an ink comprising metal nanoparticles, for example silver nanoparticles. The conductive ink can be sintered, after having been deposited on the card manufacturing support, using for example an infrared lamp, to sinter the metal nanoparticles forming the conductive tracks and the connectors in order to have a good electrical conductivity. The soldering of the electronic component is carried out with a conductive ink as described previously.

The body of the cards, in particular the non-conductive parts, is for example made from a dielectric ink in the form of a photosensitive resin which polymerizes under UV rays.

Then, the cards are superimposed on each other so that their first faces are facing each other, their connectors are in electrical contact and the component of the first card is placed in the cavity of the other card ( step 120). The step 120 of superimposing the cards can also include the nesting of the different connectors together, in particular if the connectors are of the male/female type and/or if they have complementary shapes.

Finally, the stacked cards can be put under press in order to ensure mechanical and/or electrical cohesion between the cards (step 130).

There represents, schematically and partially, an electronic circuit 200 formed by two electronic cards 210 and 220 manufactured according to the method of the invention. The electronic card 210 thus comprises connectors 211, 212 manufactured in an additive manner and present on one of its faces, called the first face 215 of the card 210, and the card 220 comprises connectors 221, 222 manufactured in an additive manner and present on a of its faces, called first face 225 of card 220.

The cards 210 and 220 are superimposed on each other, so that the connectors 211, 212 of the card 210 are opposite and in electrical contact with the connectors 221, 222 of the card 220 Furthermore, in order to reduce the size of the circuit 200 formed by the two cards 210 and 220, the connectors 211, 212, 221, 222 of the two cards are of complementary shape so as to be able to fit into each other . More particularly, in this exemplary embodiment, the connector 211 of the card 210 is of trapezoidal shape of the male type and the connector 221 of the card 220 is of the trapezoidal shape of the female type and complementary to the connector 211 so that the connectors 211 and 221 fit together. The connector 212 of the card 210 is of conical shape of the male type and the connector 222 of the card 220 is of the conical shape of the female type and complementary to the connector 212 so that the connectors 212 and 222 fit together. In this exemplary embodiment, the connectors of cards 210 and 220 are of the single-signal type.

There represents, schematically and partially, an electronic circuit 300 formed by two electronic cards 310 and 320 manufactured according to the method of the invention. The electronic card 310 thus comprises a connector 311 manufactured in an additive manner and present on one of its faces, called the first face 315 of the card 310, and the card 320 comprises a connector 321 manufactured in an additive manner and present on one of its faces, called first face 325 of card 320.

Cards 310 and 320 are superimposed on each other, so that connectors 311 and 321 are facing each other and in electrical contact.

In this exemplary embodiment, connectors 311 and 321 are of the multi-signal type. Furthermore, in order to reduce the bulk of the circuit 300 formed by the two cards 310 and 320, the connectors are of complementary shape and fit into each other, more particularly the connector 311 is of the male type and the connector 321 is of the female type with a complementary shape to connector 311.

There represents, schematically and partially, an electronic circuit produced according to one embodiment of the invention.

Circuit 400 includes three electronic cards 410, 420, 430.

The first card 410 comprises electronic components 451 and electrically conductive connectors 411 and 412 placed on its first face 4101. The second card 420 comprises on its first face 4201 cavities 442 facing the components 451 of the first card 410 and the connectors electrical conductors 421, 422 facing the connectors 411, 412 of the first card 410.

On its second face 4202, the second card 420 comprises electronic components 452 and electrically conductive connectors 423. The third card 430 comprises on its first face 4301 cavities 443 facing the components 4542 of the second card 420 and electrically conductive connectors 433.

Thus, by superimposing these three cards 410, 420, 430, the components of the first and second cards 410, 420 are buried and the connectors of the three cards 410, 420, 430 are in electrical contact. The electrical circuit 400 is thus compact, and the location of the components 451, 452 and the connectors 411, 412, 421, 422, 423, 433 is optimized on each card 410, 420, 430.

As indicated in the previous figures, the connectors of the three cards 410, 420, 430 can be of the male or female type and/or of the single-signal or multi-signal type.

In addition, the connectors can have various sizes and shapes in order to optimize the size of the cards and the interconnection between the cards.

Claims (10)

Method (100) for manufacturing an electronic circuit (200, 300, 400) comprising:

• the additive manufacturing (110) of a first electronic card (210, 310, 410) comprising at least on a first face (4101) an electrically conductive connector (411, 412) and an electronic component (451) and the additive manufacturing ( 110) of a second electronic card (220, 320, 420) comprising at least on a first face (4201) an electrically conductive connector (421, 422) and a cavity (442), and
• the superposition (120) of the first and second electronic cards so that the first face (4101) of the first card (410) faces the first face (4201) of the second card (420) , that the electrically conductive connector (411, 412) of the first card is in electrical contact with the electrically conductive connector (421, 422) of the second card and that the electronic component (451) of the first card is placed in the cavity (442) of the second card.

Method of manufacturing an electronic circuit according to claim 1, wherein the additive manufacturing of said electrically conductive connectors of the first and second cards is chosen from inkjet printing, fused wire deposition printing or fusion printing powder bed laser. Method of manufacturing an electronic circuit according to any one of claims 1 or 2, in which said electrically conductive connectors of the first and second cards are manufactured from a conductive ink comprising silver nanoparticles and the electronic component of the first card is welded to the first card by said conductive ink. Method of manufacturing an electronic circuit according to any one of claims 1 to 3, in which the first and second electronic cards comprise non-conductive parts made of a photosensitive resin. Method of manufacturing an electronic circuit (200) according to any one of claims 1 to 4, in which said electrical conductive connectors are of conical (212, 222) or trapezoidal (211, 221) shape. Method of manufacturing an electronic circuit (200) according to any one of claims 1 to 5, in which said electrical conductive connectors (211, 212, 221, 222) are of the single-signal type. Method of manufacturing an electronic circuit (300) according to any one of claims 1 to 5, in which said electrical conductive connectors (311, 321) are of the multi-signal type. Method of manufacturing an electronic circuit (200, 300) according to any one of claims 1 to 7, in which the electrical conductive connector (211, 212, 311) of the first card (210, 310) is of the male type and the electrical conductive connector (221, 222, 321) of the second card (220, 320) is of the female type with a complementary shape to the male type connector of the first card. Method of manufacturing an electronic circuit according to any one of claims 1 to 8, in which the second card (420) also comprises on a second face (4202) at least one electronic component (452) and an electrically conductive connector ( 423) and the method comprises the additive manufacturing of a third electronic card (430) comprising at least on a first face (4301) an electrically conductive connector (433) and a cavity (443) and the superposition of the third card (430 ) on the second card (420) so that the first face (4301) of the third card (430) faces the second face (4202) of the second card (420), that the electrically conductive connector (433) of the third card (430) is in electrical contact with the electrically conductive connector (423) of the second face (4202) of the second card (420) and that the electronic component (452) of the second card (420) is placed in the cavity (443) of the third card (430). Method of manufacturing an electronic circuit according to any one of claims 1 to 9, further comprising putting the superimposed electronic cards (130) under press.