Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
  • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
  • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
  • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
  • B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
  • B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
  • B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
  • B06B1/0629—Square array
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
  • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
  • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
  • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
  • B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/03—Use of materials for the substrate
  • H05K1/0306—Inorganic insulating substrates, e.g. ceramic, glass
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/03—Use of materials for the substrate
  • H05K1/0393—Flexible materials
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/0058—Laminating printed circuit boards onto other substrates, e.g. metallic substrates
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S29/00—Metal working
  • Y10S29/001—Method or apparatus involving adhesive
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
  • Y10T156/10—Methods of surface bonding and/or assembly therefor
  • Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing
  • Y10T156/1056—Perforating lamina
  • Y10T156/1057—Subsequent to assembly of laminae
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/42—Piezoelectric device making
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49005—Acoustic transducer
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/49155—Manufacturing circuit on or in base
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49117—Conductor or circuit manufacturing
  • Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
  • Y10T29/49155—Manufacturing circuit on or in base
  • Y10T29/49165—Manufacturing circuit on or in base by forming conductive walled aperture in base

Definitions

• the present invention relates to methods for manufacturing acoustic probes comprising a set of transmitting and / or receiving elements obtained by cutting from a large transducer block. Such probes are currently used in particular in applications such as ultrasound.
• the invention relates more particularly to the means enabling electrical connections to be made between the transducer elements and the electronic devices connected to them. It facilitates the manufacture of transducers comprising a large number of elements arranged in particular in a two-dimensional arrangement.
• vias are then machined collectively in the film at the location of the elementary transducers to be interconnected.
• the connections are then made by lines etched in a metallic layer deposited on the film and in the vias. These lines are made at the level of the ceramic as well as at its periphery, so there is a flat connection on the surface of the ceramic, extended by a flexible connection which can be folded over the edges of the ceramic in a minimum of size.
• Such a method makes it possible to produce acoustically discrete connectors which can conform to geometries which are sometimes complex (curved probes and of small bulk). Nevertheless, the step of producing fine tracks with a fine pitch is carried out on a product at the end of the process and therefore of high added value and comprising critical zones for the etching of the tracks at the transition between flexible parts (flex) and rigid parts. (ceramic).
• the invention provides a connection method using a dielectric film type circuit on which the interconnection lines are produced before assembly on the active elements of the probe.
• this circuit can advantageously include interconnection lines on both sides.
• the subject of the invention is a method of manufacturing an acoustic probe comprising an interconnection circuit and elementary transducers produced in a blade of piezoelectric material comprising metallizations relating to the elementary transducers, characterized in that it comprises the following steps:
• the suitable localization method can be the focusing of an ablation laser.
• the adapted localization method can comprise the use of a mask.
• the conductive tracks are produced on the underside of the dielectric film, the adhesive layer being in contact with this underside and the layer of piezoelectric material.
• a metal mask can advantageously be produced on the surface of the dielectric film, for the subsequent step of etching the vias.
• the electrical contact between a conductive track and the metallization of the associated piezoelectric material is obtained by localized deposition of a conductive material which can be a metallic layer etched by masking or a conductive resin.
• the electrical contact between a conductive track and the metallization of associated piezoelectric material can be obtained by successive deposits of a metallization layer and a layer of masking resin, then etching to leave no layer of metallization only at the level of the vias.
• the upper face of the dielectric film comprises metal tracks.
• the etching can advantageously be carried out through a mechanical mask after having covered the upper face comprising the conductive tracks with a resin.
• the step of making electrical contact between a conductive track and the metallization of associated piezoelectric material can be carried out by depositing a layer of metal, then etching to leave the conductive layer only at the bottom. vias as will be explained later.
• FIG. 1 illustrates a first example of a flexible circuit comprising conductive tracks on the underside, used in an acoustic probe according to the invention
• FIG. 2a to 2f illustrate different steps of an example of a manufacturing method according to the invention using the flexible circuit illustrated in Figure 1;
• FIG. 3a and 3b illustrate a first example of resumption of electrical contact in vias, used in the method according to the invention
• FIG. 4a to 4d illustrate a second example of resumption of electrical contact in the vias, used in the method according to the invention
• FIG. 5 illustrates an embodiment in which 7 strips of piezoelectric elements are interconnected on 4 channels;
• FIG. 6 illustrates a second example of a flexible circuit comprising conductive tracks on the upper face, used in an acoustic probe according to the invention
• FIG. 7a to 7d illustrate different stages of an example of a manufacturing process according to the invention, using the flexible circuit illustrated in Figure 6;
• the method according to the invention initially comprises producing conductive tracks on a dielectric film which will constitute the interconnection circuit.
• a dielectric film which will constitute the interconnection circuit.
• it may be a flexible polymer film of the polyimide film type.
• the flexible circuit 11 comprises on a so-called lower face PI interconnection tracks (for example made of gilded copper) corresponding to level 1 of FIG. 1a and on a so-called upper face a metallic plane (for example in copper) 14 in which are made openings intended subsequently for the selective machining of dielectric film and corresponding to level 2 of FIG. 1.
• the superposition of levels 1 and 2 of FIG. 1a shows that voluntarily several openings are defined Ol superimposed on the same PI conductive track. This constitutes better security for the resumption of electrical contacts and also allows adjustment of the acoustic impedances as a function of the number of vias which may be produced in the dielectric film constituting the flexible circuit.
• the flexible circuit 13 comprising conductive tracks PI is laminated on a metallized layer of piezoelectric material 13.
• piezoelectric material 13 may be a piezoelectric PZT blade, metallized, in which saw cuts T
• FIG. 2a shows for this purpose the flexible circuit affixed to the piezoelectric plate.
• the metallic plane is not shown in Figure 2a to allow the conductive tracks PI to appear.
• the vias are then machined in the dielectric film, above each piezoelectric element to be connected.
• the machining is carried out through the mask present on the flexible circuit by laser ablation or by reactive ion etching, so part of the conductive track as well as the metallization of the transducer to be connected are exposed at the bottom of each via, as illustrated in Figure 2b.
• This step can be carried out in several ways and in particular according to the two variants described below.
• the resumption of the contacts is directly carried out using a thermosetting conductive resin.
• the dielectric film 11 and the metallization of the piezoelectric element form a reservoir above the points to be connected.
• the deposit of conductive resin 17 can therefore be self-positioned by simply scraping the surface of the. probe ( Figure 3a corresponding to a sectional view along the axis AA of Figure 1).
• the resumption of contacts is carried out by collective metallization, using a metal layer 15 (FIG. 4a).
• the metal deposited at the bottom of the vias makes the electrical connection between the conductive track and the metallization present at the bottom of the via.
• a masking resin 16 is then deposited which allows, by photolithography process, to define a resin mask for selectively etching the metal layer 15 and thus isolating each via (FIG. 4b). By photolithography, it is then possible to eliminate the surface while preserving a protective layer at the bottom of each via (FIG. 4c).
• FIG. 2c illustrates a configuration in which the electrical contact is ensured by pads of conductive resin 17.
• the upper Lii blade has a metallized surface Pli so as to reconstitute a continuity of ground plane ( Figure 2e).
• FIG. 5 illustrates an embodiment in which 7 symmetrical bands are interconnected on 4 ways.
• the piezoelectric elements are materialized by the dotted lines.
• this configuration allows the definition of piezoelectric elements of width and of the order of 480 ⁇ m and a track width e p of the order of 50 ⁇ m.
• the flexible circuit comprises conductive tracks on the upper face (level 2) and a ground plane P opposite side on the so-called lower face (level 1).
• the dielectric film 21 comprises on its upper face the conductive tracks PI and on its lower face the ground plane P with opening provided at the location of the transducer elements, as illustrated in FIG. 6.
• the dielectric film 21 is laminated on the layer of piezoelectric material 23 comprising cutouts T
• a resin layer is laminated over the dielectric film 21 and its conductive tracks PI. The machining of the vias is then obtained by laser ablation through a mechanical mask 24 (FIG. 7b).
• contact resumption can be carried out by collective metallization or by the use of a conductive resin, as illustrated in FIG. 7c.
• a layer of metal is deposited on the etched resin layer 26 and on the vias.
• the metal deposited at the bottom of the vias makes the electrical connection between the line and the metallization of the associated piezoelectric element.
• the resumption of contacts can be obtained by filling the vias using a thermosetting conductive resin 27.
• the deposition of conductive resin can thus be self-positioning by a simple scraping of the surface of the probe.
• a flexible circuit is produced with conductive tracks on level 1 and on level 2 corresponding respectively to the upper and lower surfaces of the dielectric film.
• Level 2 can also advantageously include a plan of mass P2.
• the process steps for making the vias and the contact resumption can be similar to those described in the second example process.
• the advantage of such a flexible circuit configuration lies in the increase in the density of the interconnections on the transducers by using a second level of connection.
• FIGS. 8a to 8d illustrate an embodiment in which 5 symmetrical bands can be connected on 3 channels.
• the conductive tracks of the upper level 1 are referenced PH, the conductive tracks of the lower level are referenced PI2.
• this configuration allows the definition of the width of piezoelectric elements ej of the order of 250 ⁇ m with a width of via e v of the order of 130 ⁇ m and a width of tracks e p of the order of 50 ⁇ m.
• Figures 8b, 8c and 8d respectively represent the sections of Figure 6a along the planes BB, CC, DD.
• the dielectric film 31 includes upper metal tracks PH and lower metal tracks PI2.
• the vias are filled with conductive resin 37; the dielectric film 31 is laminated on the layer of piezoelectric material 33, by means of a layer of adhesive 32.
• the resin 36 necessary for the process steps, has been maintained.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Ultra Sonic Daignosis Equipment (AREA)
• Transducers For Ultrasonic Waves (AREA)
• Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
• Piezo-Electric Transducers For Audible Bands (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9513175

Family Applications (1)

Country Status (7)

Families Citing this family (13)

Family Cites Families (19)

• 1997
  • 1997-11-07 FR FR9714049A patent/FR2770932B1/fr not_active Expired - Lifetime
• 1998
  • 1998-11-05 JP JP52560499A patent/JP2001509901A/ja active Pending
  • 1998-11-05 EP EP98954528A patent/EP0951366A1/fr not_active Withdrawn
  • 1998-11-05 WO PCT/FR1998/002372 patent/WO1999024175A1/fr not_active Application Discontinuation
  • 1998-11-05 KR KR1019997006079A patent/KR20000069886A/ko not_active Application Discontinuation
  • 1998-11-05 CN CNB98801680XA patent/CN1177654C/zh not_active Expired - Lifetime
  • 1998-11-05 US US09/341,112 patent/US6729001B2/en not_active Expired - Lifetime

Non-Patent Citations (1)

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