This application claims the priority benefit of French Application for Patent No. 2205570, filed on Jun. 9, 2022, the content of which is hereby incorporated by reference in its entirety to the maximum extent allowable by law.
The present disclosure generally concerns electronic devices electronic devices comprising one or a plurality of radio frequency (RF) signal transmit and/or receive antennas. It more particularly applies to device comprising one or a plurality of RF signal transmit and/or receive antennas integrated in a package of the device.
Many electronic devices, particularly mobile telephony terminals, connected objects, etc., comprise one or a plurality of RF signal transmit and/or receive antennas integrated in a package of the device, to enable to the device to communicate at a distance and wireless, by radio waves, with one or a plurality of external devices.
It would be desirable to at least partly improve certain disadvantages of known electronic devices integrating antennas, and their manufacturing methods.
For this purpose, an embodiment provides a method of manufacturing an electronic device comprising the following successive steps: a) forming a plurality of antenna elements on a first surface of a first substrate; b) dicing the first substrate to form a plurality of antenna chips, each antenna chip comprising, on a first surface corresponding to said first surface of the first substrate, one of said first antenna elements; and c) bonding one of said antenna chips onto a transfer substrate, by a second surface of the antenna chip, orthogonal to its first surface.
According to an embodiment, a first metal track is formed inside and/or on top of the transfer substrate, and the method comprises, after step c), a step of forming a second conductive track on the transfer substrate between the first antenna element and the first metal track, to electrically connect them.
According to an embodiment, the method comprises a step of depositing a first solder joint between the first antenna element and the second conductive track.
According to an embodiment, the first antenna elements are formed by depositing an electrically-conductive material over the entire first surface of the first substrate, followed by locally removing said material to define the first antenna elements.
According to an embodiment, the first antenna elements are formed by locally depositing an electrically-conductive material, for example, a conductive ink, on the first surface of the first substrate.
According to an embodiment, the method comprises, after step b), a step of forming a second antenna element on a third surface of the antenna chip, opposite to the second surface of the antenna chip.
According to an embodiment, the second antenna element is formed by locally depositing an electrically-conductive material, for example, a conductive ink, onto the third surface of the antenna chip.
According to an embodiment, the method comprises a step of depositing a second solder joint between the second and first antenna elements.
According to an embodiment, the method comprises between steps a) and b), a step of flipping the first substrate and forming a plurality of third antenna elements on a fourth surface of the first substrate, opposite to the first surface.
According to an embodiment, the first substrate is made of a semiconductor material.
According to an embodiment, the first substrate is made of glass.
According to an embodiment, the antenna chip comprises an empty or gas-filled cavity.
According to an embodiment, the antenna chip comprises two first substrates placed against each other, at least one of the two first substrates comprising a recess defining said cavity.
According to an embodiment, the first substrate is coated, during a step preceding step a), with a protection layer, at the interface with the first antenna elements.
Another embodiment provides an electronic device comprising: a) an antenna chip formed inside and on top of a first substrate, said antenna chip comprising at least one first antenna element formed on a first surface of the antenna chip; and b) a transfer substrate, wherein the antenna chip is bonded to the transfer substrate by a second surface of the antenna chip, orthogonal to its first surface.
The foregoing features and advantages, as well as others, will be described in detail in the rest of the disclosure of specific embodiments given by way of illustration and not limitation with reference to the accompanying drawings, in which:
Like features have been designated by like references in the various figures. In particular, the structural and/or functional features that are common among the various embodiments may have the same references and may dispose identical structural, dimensional and material properties.
For the sake of clarity, only the steps and elements that are useful for an understanding of the embodiments described herein have been illustrated and described in detail. In particular, the forming (particularly the shape) and the operation of the antennas of the described devices have not been detailed. Further, the various electronic circuits of the described devices, particularly the electronic circuits for controlling (reading and/or excitation) the antennas have not been detailed. The forming or the implementation of these elements is within the abilities of those skilled in the art based on the indications of the present disclosure.
Unless indicated otherwise, when reference is made to two elements connected together, this signifies a direct connection without any intermediate elements other than conductors, and when reference is made to two elements coupled together, this signifies that these two elements can be connected or they can be coupled via one or more other elements.
In the following disclosure, unless otherwise specified, when reference is made to absolute positional qualifiers, such as the terms “front”, “back”, “top”, “bottom”, “left”, “right”, etc., or to relative positional qualifiers, such as the terms “above”, “below”, “upper”, “lower”, etc., or to qualifiers of orientation, such as “horizontal”, “vertical”, etc., reference is made to the orientation shown in the figures.
Unless specified otherwise, the expressions “around”, “approximately”, “substantially” and “in the order of” signify within 10%, and preferably within 5%.
Antenna 101 comprises a first antenna element 101a formed on an antenna chip 103 and more particularly on top of and in contact with a surface 105 of antenna chip 103.
Antenna 100 is, for example, a telephone antenna configured for capturing and/or emitting electromagnetic waves and more precisely radio-frequency (RF) waves. Antenna 100 enables, for example, to establish radio communications.
As an example, antenna chip 103 comprises at the level of its surface 105, for example all over surface 105, a protection layer 106. Protection layer 106 is, for example, an electrically-insulating layer, for example made of PolyBenzlmidazole (PBI) and/or of PolyBenzOxazole (PBO).
Device 100 further comprises a transfer substrate 107 having antenna chip 103 bonded thereto. More particularly, antenna chip 103 is bonded to a connection surface of substrate 107, that is, the upper surface of substrate 107 in the orientation of the drawings, by a second surface 109 (lower surface of the chip in the orientation of the drawings) orthogonal to its first surface 105.
As an example, chip 103 has the shape of a parallelepipedal block. As an example, the first surface 105 of chip 103 has dimensions in the range from 100 μm by 100 μm to 1 mm by 1 mm, for example in the range from 200 μm by 200 μm to 800 μm by 800 μm, for example, in the order of 400 μm by 800 μm.
As an example, chip 103 comprises a substrate 117 made of a semiconductor material, for example of silicon. As a variant, chip 103 comprises a substrate made of an electrically-insulating material, for example of glass. As an example, protection layer 106 is present when the substrate of chip 103 is made of a semiconductor material. Antenna element 101a may then be formed on top of and in contact with the surface of protection layer 106 opposite to the chip substrate. Protection layer 106 is, for example, absent when the chip substrate is made of an electrically-insulating material. Antenna element 101a may then be formed on top of and in contact with the chip substrate.
Transfer substrate 107 is, for example, made of an organic material, for example a resin. As an example, transfer substrate 107 is planar.
As an example, first antenna element 101a comprises one or a plurality of tracks made of an electrically-conductive material, for example forming a coil, one or a plurality of spirals, or any other planar pattern suited for emitting and/or receiving radio frequency waves. As an example, first antenna element 101a corresponds to a coil formed by an array of parallel conductive lines coupled together by their ends. As an example, the spacing between two neighboring lines and the width of the lines are constant. The spacing between two neighboring lines is, for example, in the range from 1 μm to 500 μm, for example from 10 μm to 100 μm, for example, in the order of 45 μm. The width of the lines is, for example, in the range from 1 μm to 500 μm, for example from 5 μm to 100 μm, for example in the order of 20 μm.
In the illustrated example, antenna 101 is coupled to a first connection track 111a formed inside and/or on top of transfer substrate 107, for example in an interconnection array formed on the upper surface side of substrate 107. As an example, connection track 111a corresponds to a metal track connected, for example coupled, to an integrated circuit, not shown, for example to a processing unit, bonded and connected to transfer substrate 107.
As an example, first antenna element 101a is connected, for example coupled, to metal track 111a by a second conductive track 111b formed on the upper surface of transfer substrate 107. Second conductive track 111b is, for example, formed between first antenna element 101a and a connection pad 113 of transfer substrate 107, itself connected, for example, coupled, to metal track 111a. As an example, connection pad 113 is flush with the upper surface of transfer substrate 107. As a variant, connection pad 113 is located on top of and in contact with an upper surface of substrate 107 and, more precisely, partly on top of and in contact with connection track 111a.
As an example, connection pad 113 is made of a metallic material, for example copper.
As an example, antenna element 101a and second conductive track 111b are made of a same conductive material, for example, a conductive ink or any other conductive material likely to be deposited on a surface of a substrate, for example, a metallic material, for example copper or silver.
Antenna element 101a and second conductive track 111b are connected together, for example, coupled, by means of a solder joint 115. Solder joint 115 corresponds, for example, to a solder ball or to a sintering paste, or also a drop of a conductive ink. Solder joint 115 is made of a conductive material. It may be an alloy of tin (Sn), of silver (Ag), of gold (Au), of lead (Pb), of copper (Cu), of indium (In), and/or of bismuth (Bi), etc., such as SnPb, SnAgCu, SnAg, AuSn, InSn, SnBi, etc.
Thus, according to an aspect of the embodiment of
As a variant (not shown), the device of
As an example, protection layer 106, when it is present, is deposited, before the step of forming of first antenna elements 101a, on the upper surface of substrate 117, for example in contact with the upper surface of substrate 117. Layer 106 continuously extends, for example, over the entire upper surface of substrate 117.
As an example, first antenna elements 101a are formed by local deposition of a conductive material, for example a conductive ink, on the upper surface of substrate 117, possibly followed by a sintering. The local deposition is, for example, implemented by inkjet printing, or by any other suitable method of local deposition of a conductive material on a substrate. As a variant, a continuous layer of a conductive material, for example, metallic, for example made of copper, is deposited over the entire upper surface of the substrate, and then locally removed, for example, by photolithography.
At the end of this step, although this is not shown, each chip 103 is transferred onto the upper surface of a transfer substrate 107, for example by use of a pick-and-place tool, so that the surface 105 supporting first antenna element 101a is substantially orthogonal to transfer substrate 107. As an example, chip 103 is bonded to transfer substrate 107 via an adhesive film, glue, or a solder material. As an example, second conductive track 111b and solder joint 115 are successively deposited after the transfer and the bonding of antenna chip 103 onto the connection surface of transfer substrate 107.
Solder joint 115 is, for example, formed by laser solder ball jetting.
The device 300 of
Second antenna element 301b is, for example, formed on top of and in contact with chip 303. Second antenna element 301b is connected, for example coupled, to first antenna element 101a by a solder joint 323.
Second antenna element 301b is, for example, made of the same material as first antenna element 101a. As an example, second antenna element 301b has the same shape and the same size as first antenna element 101a. In other words, the first 101a and second 301b antenna elements comprise conductive lines of same length, of same width, and having a similar spacing between two successive lines. Second antenna element 301b is, for example, formed after the step of transfer of chip 303 onto transfer substrate 107. As an example, second antenna element 301b is formed by local deposition of a conductive material, for example, a conductive ink, on the upper surface of substrate 117, possibly followed by a sintering. The local deposition is, for example, implemented by inkjet printing, or by any other suitable method of local deposition of a conductive material on a substrate.
As an example, solder joint 323 is deposited at the end of the step of forming of second antenna element 301b. As an example, solder joint 323 is similar to solder joint 115 by its composition, its size, and its deposition method. As an example, solder joints 115 and 323 are deposited within a single step.
The device 400 of
The third antenna element 401c is, for example, formed on top of and in contact with a protection layer 426, located at the level of the surface 425 of chip 403. More precisely, antenna element 401c is, for example, formed on top of and in contact with the surface of protection layer 426 opposite to the chip substrate. Protection layer 426 is, for example, similar to the protection layer 106 located at the level of surface 105 of chip 403. If protection layer 426 is omitted, third antenna element 401c is, for example, formed on top of and in contact with the substrate of chip 403. Third antenna element 401c is connected, for example, coupled, to the second antenna element 301b formed on surface 321 of chip 403 for example by a solder joint 427.
Third antenna element 401c is, for example, made of the same material as the first 101a and second 301b antenna elements and is, for example, of same size as the latter. In other words, the first 101a, second 301b, and third 401c antenna elements comprise conductive lines of same length, of same width, and having a similar spacing between two successive lines.
As an example, solder joint 427 is similar to solder joints 115 and 323 by its composition and its size.
Device 400 is manufactured from a structure illustrated in
The method of manufacturing device 400 illustrated in
Based on the structure illustrated in
As an example, third antenna elements 491c are formed by a forming method similar to the method of forming of first antenna elements 101a.
Trenches 119 cross, for example, protection layers 106 and 426 when they are present.
At the end of this step, although this is not shown in
The device 600 of
Substrates 631 are, for example, made of a semiconductor material such as silicon. As a variant, substrates 631 are made of glass.
An advantage of the introduction of a gas or of vacuum at the center of chip 603 and more particularly between two antenna elements is that this enables to limit interferences or crosstalk between the waves captured by first antenna element 101a and the waves captured by third antenna element 401c.
Protection layer 635 corresponds, at the end of the method of manufacturing device 600, to protection layer 106 or to protection layer 426. Layer 635 is thus of same nature as layers 106 and 426.
As a variant, antenna elements 601x are formed after the step of bonding of the two substrates 631 to each other.
As an example, the trenches 119 of the structure illustrated in
At the end of this step, although this is not shown in
An advantage of the described method is that it enables to maximize the size of the antenna with respect to the size of the chip and to capture electromagnetic waves in all directions. This in particular enables to increase the performance of the antenna.
An advantage of the described method is that it may easily adapt to many types of antennas, for example, to Bluetooth antennas, to 3G, 4G, or 5G antennas.
Various embodiments and variants have been described. Those skilled in the art will understand that certain features of these various embodiments and variants may be combined, and other variants will occur to those skilled in the art. In particular, the embodiment of
Further, the described embodiments are not limited to the examples of materials and of dimensions mentioned in the present disclosure.
Finally, the practical implementation of the described embodiments and variations is within the abilities of those skilled in the art based on the functional indications given hereabove.
Number | Date | Country | Kind |
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2205570 | Jun 2022 | FR | national |