Sonar module

Abstract

The invention relates to a sonar module (20) comprising a first and a second waterborne sound transducer (24) and a printed circuit board (22). The first and second waterborne sound transducers (24) each have a first and a second electrode for contacting. The printed circuit board (22) comprises a first electrical contact and a second electrical contact, the first electrical contact being electrically connected to the first electrode of the first waterborne sound transducer and the second electrical contact being electrically connected to the first electrode of the second waterborne sound transducer. The printed circuit board has a through-opening or a plurality of through-openings between the first contact and the second contact.

Description

[0001] Sonar module

[0002] Description

[0003] The invention relates to a sonar module and its manufacturing method.

[0004] Sonar modules typically have multiple subsea transducers. To connect the sonar modules, it is common practice to arrange them on a circuit board. However, this poses several problems. For example, one side of the subsea transducers is firmly connected to the circuit board. The other side, however, can vibrate freely. This leads to what is known as flutter of the subsea transducer on the side of the transducer facing away from the circuit board. When sound waves are transmitted, this flutter distorts the emitted frequency spectrum. Further problems exist with swelling and pressurization.

[0005] Furthermore, the waterborne sound transducers are often encapsulated with a potting compound. However, when using a circuit board, excess potting compound or a (conductive) adhesive used to attach the waterborne sound transducers to the circuit board cannot drain away, which can lead to stresses or the risk of using too little potting compound to prevent stresses. Another problem is the mutual interference between the waterborne sound transducers due to vibrations transmitted via the circuit board.

[0006] The object of the present invention is therefore to create an improved concept for sonar modules.

[0007] This problem is solved by the subject matter of the independent patent claims. Further advantageous embodiments are the subject matter of the dependent patent claims.

[0008] Embodiments show a sonar module with a plurality of waterborne sound transducers, in particular a first and a second waterborne sound transducer, and a circuit board. The first and second waterborne sound transducers each have a first and a second electrode for contacting.

[0009] The circuit board has a first electrical contact and a second electrical contact. The first electrical contact is electrically connected to the first electrode of the first water sound transducer, and the second electrical contact is electrically connected to the first electrode of the second water sound transducer. The electrical connection is preferably established by means of a soldered contact or a conductive adhesive. The water sound transducer is thus contacted on one side via the circuit board. The circuit board can have a third or a fourth contact for each second electrode. The third electrical contact can be electrically connected to a second electrode of the first water sound transducer, and the further second electrical contact can be electrically connected to a second electrode of the second water sound transducer.In particular, the circuit board has, for example, one electrical contact per waterborne sound transducer (for one-sided contacting of the waterborne sound transducers) or two electrical contacts (for two-sided contacting of the waterborne sound transducers).

[0010] Alternatively, the sonar module can have a further circuit board, in particular for contacting the second electrodes of the waterborne sound transducers. The further circuit board can have a first electrical contact and a second electrical contact, wherein the first electrical contact of the further circuit board is electrically connected to a second electrode of the first waterborne sound transducer opposite the first electrode, and wherein the second electrical contact of the further circuit board is electrically connected to a second electrode of the second waterborne sound transducer opposite the first electrode. Alternatively, the second electrodes of the waterborne sound transducers can also be contacted, for example, by means of a wire.

[0011] Furthermore, the circuit board has an opening or a plurality of openings between the first contact and the second contact. The opening in the circuit board is preferably larger, or the openings of the plurality of openings in the circuit board are preferably larger, than an opening in the circuit board for receiving component contacts for contacting the rear of the circuit board. The opening in the circuit board for receiving component contacts refers to the opening for the pins of the components in through-hole mounting (e.g. THT - Through-Hole Technology) or a common size of these openings if no openings are provided, such as in surface-mounted components (e.g. SMD - Surface-Mounted Device). Furthermore, the opening is preferably arranged such that there is a straight line between the first water sound barrier transducer and the opening intersects the opening.A breakthrough is specifically a hole in the circuit board that is completely enclosed by the circuit board.

[0012] Preferably, the water sound transducers are enclosed in a potting material.

[0013] The idea is to use a circuit board with openings to contact the underwater sound transducers on at least one side. On the one hand, the openings allow excess potting compound to escape through the circuit board, thus avoiding any stresses in the sonar module. Furthermore, the openings decoupling the underwater sound transducers from one another means that vibrations from one underwater sound transducer are at least not completely transmitted via the circuit board to other underwater sound transducers. In conjunction with another circuit board that contacts the second electrodes of the underwater sound transducers, it is also possible to make the openings large enough to allow the potting compound to be applied over a large area between the two circuit boards. This reduces the risk of the potting compound hardening before it has completely flowed between the two circuit boards.The contacting of the second electrodes of the water sound transducers by means of the additional circuit board also has the advantage of reducing the flutter of the water sound transducers.

[0014] In exemplary embodiments, the additional circuit board has one or more openings between the first and second contacts, such that the additional circuit board has a larger circuit-board-free area between the first and second contacts than the circuit board between the first and second contacts. This combines the aforementioned advantages. This means that, on the one hand, the circuit board decouples the waterborne sound transducers and also allows the potting compound to escape. The larger openings in the additional circuit board allow the potting compound to be introduced between the two circuit boards, reducing flutter.

[0015] For example, the opening in the further circuit board is larger or the total of a plurality of openings in the further circuit board is larger than 20%, preferably larger than 40%, more preferably larger than 55% or larger than 70% of a total area of ​​the further circuit board in the absence of the opening or openings of the plurality of openings. This ensures that the opening(s) are also large enough to fill the potting compound between the circuit boards. In particular, a lateral extent of the further circuit board in the region of the first or second contact can be smaller than a lateral extent of the first water sound transducer or the second water sound transducer. Lateral refers to the direction laterally of the stack of the two circuit boards and the water sound transducers arranged between them, i.e. not viewed from the direction of a circuit board.For example, it is possible that the waterborne sound transducers are arranged in (straight, curved or angled) lines and the circuit board runs in corresponding paths.

[0016] In embodiments, there is a closed polygonal line which encloses exactly one contact of the circuit board, so that the closed polygonal line runs at least 50%, preferably 60%, more preferably 75% through the opening in the circuit board or several openings of the plurality of openings in the circuit board.

[0017] Further embodiments show that the first and second waterborne sound transducers are part of a plurality of waterborne sound transducers, wherein the waterborne sound transducers of the plurality of waterborne sound transducers each have a first and a second electrode for contacting. The circuit board has one contact per waterborne sound transducer, which is electrically connected to the first electrode of a waterborne sound transducer of the plurality of waterborne sound transducers assigned to the contact. The circuit board has one opening or a plurality of openings at least between adjacent contacts. Thus, all waterborne sound transducers can have improved decoupling from one another.

[0018] Analogously, a method for producing a sonar module is disclosed, comprising the following steps: a) providing one and a second waterborne sound transducer (24), wherein the first and the second waterborne sound transducer each have a first and a second electrode for contacting; b) providing a circuit board (22) having a first electrical contact and a second electrical contact; c) electrically connecting the first electrical contact of the circuit board to the first electrode of the first waterborne sound transducer; d) electrically connecting the second electrical contact of the circuit board to the first electrode of the second waterborne sound transducer;e) Providing a further circuit board with a first electrical contact and a second electrical contact, wherein the further circuit board has an opening between the first and the second contact, so that the further circuit board has a larger circuit board-free area between the first and the second contact than the circuit board between the first and the second contact; f) Electrically connecting the first electrical contact of the further circuit board to a second electrode of the first water-borne sound transducer opposite the first electrode; g) Electrically connecting the second electrical contact of the further circuit board to a second electrode of the second water-borne sound transducer opposite the first electrode. After steps f) and g), the spaces between the circuit boards can be filled with a potting compound in a step h).

[0019] Preferred embodiments of the present invention are explained below with reference to the accompanying drawings. It shows:

[0020] Fig. 1: a schematic representation of an embodiment of a sonar module with a circuit board, wherein Fig. 1a is a plan view and Fig. 1b is a perspective view;

[0021] Fig. 2: a schematic representation of an embodiment of the sonar module with two circuit boards, wherein Fig. 2a is a top view and Fig. 2b is a perspective view; Fig. 3: a schematic representation of a combination of the embodiments of the sonar module from Fig. 1 and Fig. 2, wherein Fig. 3a is a top view and Fig. 3b is a perspective view.

[0022] Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical, functionally equivalent or equivalent elements, objects and / or structures in the different figures are provided with the same reference numerals, so that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another.

[0023] Fig. 1 shows a schematic representation of an embodiment of a sonar module 20. Fig. 1a shows a top view of the sonar module 20, and Fig. 1b shows a perspective view. The representation also differs with regard to the shape of the openings 26. This is described below.

[0024] The sonar module 20 comprises a circuit board 22 with waterborne sound transducers 24a, 24b, 24c, 24d, 24e arranged thereon. The five waterborne sound transducers 24 shown are only examples, and any number of a plurality of waterborne sound transducers can be used, provided there is sufficient space for the waterborne sound transducers on the circuit board. The waterborne sound transducers 24 have two electrodes (not shown), for example one electrode on the head side and one electrode on the foot side. One electrode, in this case the foot-side electrode, is contacted by an electrical contact 25 on the circuit board 22, i.e. is electrically connected to the same. The contact 25, below the waterborne sound transducer 24a, is shown in dashed lines as an example of the contacts. The second electrode can be contacted in any other way, for example also via the circuit board.For this purpose, the second electrode can also be arranged on the base side of the waterborne sound transducer or, for example, be led to the circuit board with a wire. However, the type of contact is not important for the further disclosure. A large number of openings 26 are arranged between the contacts 25. Fig. 1a shows, by way of example, 6 openings 26 per contact 25. The openings 26 enclose the contacts by at least 50%, preferably at least 60%, more preferably at least 75%. This means that there is a closed polygonal line 27 which encloses exactly one contact 25 of the circuit board 22, so that the closed polygonal line 27 runs at least 50% through the opening 26 of the circuit board 22 or several openings 26 of the plurality of openings 26 in the circuit board 22. By way of example, a polygonal line 27 is shown in dashed lines for each of the contacts to the waterborne sound transducers 24d, 24e. In Fig.Figure 1b shows alternatively shaped apertures 26. The apertures 26 form one or two partial circles. In the case of one partial circle, there is only one connection from the circuit board to the interior of the partial circle; in the case of two partial circles, there is another connection, each concealed behind the waterborne sound transducers 24. Furthermore, a mixture of the shapes of the apertures 26 is also possible.

[0025] Fig. 2 shows a schematic representation of the sonar module 20 in an alternative embodiment. Fig. 2a again shows a plan view, analogous to Fig. 1a, while Fig. 2b again reveals a perspective view. The sonar module 20 comprises a circuit board 22a and a further circuit board 22b. With regard to the features, the circuit board 22a is identical to the circuit board 22 from Fig. 1, only the openings 26 are larger. Thus, the circuit board-free area is larger, at least between some contacts in Fig. 2 than in Fig. 1. The circuit board forms tracks in the area of ​​the waterborne sound transducers 24, for example. No further openings need to be arranged between contacts of the circuit board that lie on a track, although this is also possible. The circuit board-free area between these contacts can also be smaller than in the exemplary embodiment from Fig. 1.The additional circuit board 22b serves, for example, to provide mechanical stability for the circuit board-waterborne transducer stack. The waterborne transducers 24 have an electrical connection to the circuit board 22a and the additional circuit board 22b.

[0026] While the smaller openings in Fig. 1 serve to decouple the vibrations of the waterborne sound transducers from each other and allow the potting compound to escape through the openings and thus into the circuit board 22, the larger openings 26 in Fig. 2 allow the gap between the circuit board 22a and the further circuit board 22b to be filled with a potting compound. Furthermore, the arrangement with two circuit boards in Fig. 2 significantly reduces the flutter of the waterborne sound transducers 24.

[0027] The openings 26 in Fig. 2 preferably have an area that is larger than 20%, preferably larger than 40%, more preferably larger than 60% of the total area of ​​the additional circuit board in the absence of the opening(s). In the exemplary embodiment of Fig. 2, the circuit board 22a, in the absence of the openings, has the same size as the additional circuit board 22b.

[0028] The lateral extent of the additional circuit board 22b can be smaller in the area of ​​the contacts than the lateral extent of the associated waterborne sound transducers. Such an arrangement is shown with respect to the waterborne sound transducers 24c, 24d, and 24e and the two associated tracks of the circuit board 22a. In contrast, the upper track of the circuit board 22a completely conceals the waterborne sound transducers 24a and 24b.

[0029] Fig. 3 shows a schematic representation of a combination of the exemplary embodiments from Fig. 1 and Fig. 2. Fig. 3a again shows a top view, and Fig. 3b a perspective view of the resulting exemplary embodiment. Regarding the naming of the printed circuit boards, the lower printed circuit board 22 can be referred to as the "(first) printed circuit board" and the upper printed circuit board 22a as the "second or further printed circuit board."

[0030] The disclosed (water) sound transducers are designed for use underwater, particularly in the sea. The sound transducers can convert water sound into an electrical signal (e.g., voltage or current) corresponding to the sound pressure, the water sound signal. Furthermore, it is possible for the sound transducers to convert an applied electrical voltage into water sound. The sound transducers can therefore be used as water sound receivers and / or as water sound transmitters. The sound transducers can comprise a piezoelectric material, such as a piezoceramic, as the sensor material. The sound transducers can be used for (active and / or passive) sonar (sound navigation and ranging). Hydrophones, for example, can be used as water sound transducers. The sound transducers are preferably not suitable for medical applications and are not used for medical applications.

[0031] Although some aspects have been described in connection with a device, it is understood that these aspects also represent a description of the corresponding method, so that a block or component of a device can also be understood as a corresponding method step or as a feature of a method step. Similarly, aspects described in connection with or as a method step also represent a description of a corresponding block, detail, or feature of a corresponding device.

[0032] The above-described embodiments are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented in the description and explanation of the embodiments herein.

[0033] List of reference symbols:

[0034] 20 Sonar module

[0035] 22 Circuit board 24 Water-borne sound transducer

[0036] 25 Contact of the circuit board

[0037] 26 Breakthrough

[0038] 27 Polygon

Claims

Patent claims 1 . Sonar module (20) with the following features: - a first and a second water sound transducer (24, 24a, 24b, 24c, 24d, 24e) (24), wherein the first and the second water sound transducer (24, 24a, 24b, 24c, 24d, 24e) each have a first and a second electrode for contacting; - a circuit board (22, 22a, 22b) having a first electrical contact (25) and a second electrical contact (25), wherein the first electrical contact (25) is electrically connected to the first electrode of the first water sound transducer and wherein the second electrical contact (25) is electrically connected to the first electrode of the second water sound transducer; - wherein the circuit board (22, 22a, 22b) has an opening (26) or a plurality of openings (26) between the first contact (25) and the second contact (25).

2. Sonar module (20) according to claim 1, wherein the circuit board (22, 22a, 22b) has a third electrical contact (25) and a fourth electrical contact (25), wherein the third electrical contact (25) is electrically connected to a second electrode of the first water sound transducer and wherein the further second electrical contact (25) is electrically connected to a second electrode of the second water sound transducer.

3. Sonar module (20) according to one of the preceding claims, - wherein the sonar module has a further circuit board (22, 22a, 22b), - wherein the further circuit board (22, 22a, 22b) has a first electrical contact (25) and a second electrical contact (25), wherein the first electrical contact (25) is electrically connected to a second electrode of the first water-borne sound transducer opposite the first electrode, wherein the second electrical contact (25) is electrically connected to a second electrode of the second water-borne sound transducer opposite the first electrode.

4. Sonar module (20) according to claim 3, - wherein the further circuit board (22, 22a, 22b) has an opening (26) or a plurality of openings between the first and the second contact (25), so that the further circuit board (22, 22a, 22b) has a larger circuit board-free area between the first and the second contact (25) than the circuit board (22, 22a, 22b) between the first and the second contact.

5. Sonar module (20) according to claim 4, wherein the opening (26) of the further circuit board (22, 22a, 22b) is larger or a total of the plurality of openings of the further circuit board (22, 22a, 22b) is larger than 20% of a total area of ​​the further circuit board (22, 22a, 22b) in the absence of the opening or the openings of the plurality of openings.

6. Sonar module (20) according to one of claims 4 or 5, wherein a lateral extension of the further circuit board (22, 22a, 22b) in the region of the first or second contact is smaller than a lateral extension of the first water sound transducer or the second water sound transducer.

7. Sonar module (20) according to one of the preceding claims, wherein the water sound transducers (24, 24a, 24b, 24c, 24d, 24e) are enclosed in a potting material.

8. Sonar module (20) according to one of the preceding claims, wherein the opening (26) of the circuit board (22, 22a, 22b) is larger or the openings of the plurality of openings of the circuit board (22, 22a, 22b) are larger than an opening of the circuit board (22, 22a, 22b) for receiving component contacts for contacting the circuit board on the back.

9. Sonar module (20) according to one of the preceding claims, wherein there is a closed polygonal line (27) which encloses exactly one contact (25) of the printed circuit board (22, 22a, 22b), so that the closed polygonal line (27) runs at least 50% through the opening (26) of the printed circuit board (22, 22a, 22b) or several openings of the plurality of openings of the printed circuit board (22, 22a, 22b).

10. Sonar module (20) according to one of the preceding claims, - wherein the first and the second water sound transducer (24, 24a, 24b, 24c, 24d, 24e) (24) are part of a plurality of water sound transducers, wherein the water sound transducers (24, 24a, 24b, 24c, 24d, 24e) of the plurality of water sound transducers each have a first and a second electrode for contacting; - wherein the circuit board (22, 22a, 22b) (22) has one contact (25) per water sound transducer (24, 24a, 24b, 24c, 24d, 24e) which is electrically connected to the first electrode of a water sound transducer of the plurality of water sound transducers associated with the contact (25); - wherein the printed circuit board (22, 22a, 22b) (22) has at least one opening (26) or a plurality of openings between adjacent contacts. 11 . Method for producing a sonar module (20) with the following steps: a) providing one and a second water sound transducer (24), wherein the first and the second water sound transducer (24, 24a, 24b, 24c, 24d, 24e) each have a first and a second electrode for contacting; b) providing a circuit board (22, 22a, 22b) (22) with a first electrical contact (25) and a second electrical contact c) electrically connecting the first electrical contact of the circuit board (22, 22a, 22b) to the first electrode of the first water sound transducer; d) electrically connecting the second electrical contact of the circuit board (22, 22a, 22b) to the first electrode of the second water sound transducer;e) providing a further circuit board (22, 22a, 22b) with a first electrical contact (25) and a second electrical contact, wherein the further circuit board (22, 22a, 22b) has an opening (26) between the first and the second contact (25), so that the further circuit board (22, 22a, 22b) has a larger circuit board-free area between the first and the second contact (25) than the circuit board (22, 22a, 22b) between the first and the second contact; f) electrically connecting the first electrical contact of the further circuit board (22, 22a, 22b) to a second electrode of the first water-borne sound transducer opposite the first electrode; g) electrically connecting the second electrical contact of the further circuit board (22, 22a, 22b) to a second electrode of the second water-borne sound transducer opposite the first electrode.

12. The method according to claim 11, wherein after steps f) and g) the spaces between the circuit boards are filled with a potting compound in a step h).

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