JPS605630Y2 - surface acoustic wave device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of a surface acoustic wave device, and particularly to its exterior.

A surface acoustic wave device excites surface acoustic waves on the surface of a piezoelectric material using an alternating current electric field applied to interdigitated electrodes.

Various methods have been considered for the exterior of this surface acoustic wave device.

The most commonly used type is the TO type can seal as shown in FIG.

Since the lead wires are sealed in glass and the case and base are assembled by welding, the sealing and shielding effects are high, and the integrity of the package is high.

However, it has the disadvantage of high cost, and a low-cost package is required.

Further, the electrodes and lead terminals are connected by a wire bodding method, which increases the number of man-hours, has drawbacks in reliability, and increases costs.

Therefore, it has been considered to connect the lead terminals directly to the piezoelectric substrate by soldering, but since the surface of the piezoelectric substrate is polished and the adhesive strength of the electrodes deposited thereon is weak, the external force applied to the lead terminals There is a problem with the metal peeling off.

The present invention aims to solve the above-mentioned problems and provide a surface acoustic wave device that is easy to assemble, has high reliability, and is low in cost.

The present invention uses a metal plate for the exterior in place of the conventional case, and also uses this metal plate for connections.

An example of a surface acoustic wave device according to the present invention will be described below with reference to the drawings.

FIG. 2 is a perspective view of the surface acoustic wave device according to the present invention before assembly.

A surface acoustic wave element 11 having intersecting comb-shaped electrodes provided on a substrate, and lead terminals 12 for connecting and fixing the electrodes to wiring on a printed circuit board are placed at predetermined positions on a metal plate 13.

An insulating layer is provided on the surface of the metal plate 13 on which the surface acoustic wave element and lead terminals are placed.

The insulating layer does not need to be provided over the entire surface, and may be provided only on the portion where the lead frame contacts.

The insulating layer is provided by a method of applying a resin, but it may also be provided by a method of simply oxidizing the surface of the metal to form an oxide film.

The example in FIG. 2 shows the case where the surface of the metal is oxidized.

A depression for embedding the surface acoustic wave element 11 is previously formed in the metal plate 13 by press molding, and the surface acoustic wave element 11 is inserted into the depression so that its surface is the same as the surface of the lead terminal 12. I'll keep it.

The lead terminal 12 may be formed into a lead frame shape as shown in FIG. 2, and the connecting piece 12' may be removed after assembly.

The metal plate 13 is bent in two and the surface acoustic wave element 11 and the lead terminal 12 are sandwiched and fixed, and the folded surface of the metal plate 13 is used as a wiring board.

Although it may be provided as is on the insulating layer made of an oxide film, an insulating layer 14 made of resin is further provided, and a metal layer 15 made of copper foil or the like is formed thereon.

The metal layer 15 is arranged so as to connect the electrode of the surface acoustic wave element 11 and the lead terminal 12 when the metal plate 13 is bent, and is formed by pre-shaping it into a semicircle, bending it, and then thermocompression bonding. The electrode and lead terminal are completely connected.

FIG. 3 shows a cross section of the metal plate 13 when bent.

The surface acoustic wave element 11 is fixed in the recess of the metal plate 13 using an adhesive 16, and a thermosetting resin is applied to the periphery of the metal plate 13, and the surface acoustic wave element 11 is bonded by thermocompression after bending. , it is preferable to seal the surface acoustic wave element 11.

In addition, although a surface acoustic wave device may require a gap on the propagation path of the surface acoustic wave, the gap can be easily formed by changing the shape of the metal plate 13.

Furthermore, the present invention packages the surface acoustic wave element with a metal plate, and this metal plate can also be used as a shield plate.

A complete shielding effect can be obtained by directly connecting the lead terminal to the metal plate and shielding the part of the lead terminal that is in contact with the grounded part without forming an insulating layer over the entire surface of the metal plate. It will be done.

According to the present invention, a surface acoustic wave device having an extremely simple structure can be obtained.

Since the number of parts is small and assembly is easy, the number of man-hours can be significantly reduced, and costs can also be reduced.

In addition, it has an excellent shielding effect and the connection is reliable, so a highly reliable product can be obtained.

Furthermore, it is small and lightweight, and can be used in surface acoustic wave devices for various purposes.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional surface acoustic wave device, FIG. 2 is a perspective view of an embodiment of the present invention, and FIG. 3 is a side sectional view of the embodiment of the present invention. 11...Surface acoustic wave element, 12...Lead terminal, 13...Metal plate.

Claims (3)

[Scope of utility model registration request] (1) A surface acoustic wave device comprising intersecting comb-shaped electrodes on a substrate, one end of which is formed close to the electrode of the surface acoustic wave device, and a wiring pattern is formed through a lead terminal and an insulating layer. In a surface acoustic wave device including a formed metal plate, the surface acoustic wave element is arranged so that the surface of the surface acoustic wave element and one surface of the lead terminal are approximately at the same height, and the metal plate is folded back to form the wiring pattern. The electrodes of the surface acoustic wave element and the lead terminal are connected, and the surface acoustic wave element and the lead terminal are sandwiched through an insulating layer that is also formed on the part of the metal plate that contacts the lead terminal. A surface acoustic wave device characterized by being integrally supported by. (2) The surface acoustic wave device according to claim 1, which is a registered utility model, wherein a grounded lead terminal among the lead terminals is electrically connected to the metal plate. (3) Utility model registration claim 1, in which the insulating layer of the metal plate is made of an oxide formed by oxidizing the surface of the metal plate
The surface acoustic wave device described in .