JPH03262314A - Surface acoustic wave device - Google Patents

Abstract

PURPOSE:To prevent the missing of a resin package due to a folded lead by providing a notch or a narrow width part on a tip of a lead placed to an outside of the resin package while being penetrated through the resin package air-tightly and folding the lead at the notch or the narrow width part. CONSTITUTION:A notch 25 is formed to the prescribed part of a lead 22 and a resin package 20 is formed by the resin molding method and the tip 23b of the lead 22 penetrated air-tightly through the side wall of the resin package 20 is folded at its notch 25 by the press working. Thus, even when the tip 23b of the lead 22 prolonged from its side wall is folded at a position close to the outer side face of the resin package 20, a stress caused by the folding is concentrated to the notch 25 with a low mechanical strength. Thus, the occurrence of chipping due to the folded lead 22 of the thermoplastic resin package 20 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a surface acoustic wave device, and particularly to a surface acoustic wave device in which a surface acoustic wave element is sealed with a resin package.

(Prior Art) Conventionally, a surface acoustic wave device uses LiT as shown in FIG.
The surface acoustic wave element (1) has a piezoelectric substrate such as aO3, and has at least a comb-shaped input electrode and a comb-shaped output electrode spaced apart from each other.
) is glued to a stem (2) made of an insulator such as glass, and multiple lead pins (
3), each electrode is connected with a bonding wire, and the surface acoustic wave element (1) is connected to the stem (2) and the metal shell (
4) It is formed into a sealed structure.

However, since surface acoustic wave devices are generally produced in small quantities in a wide variety of products with different specifications depending on the user, the above structure increases the manufacturing cost and makes it difficult to reduce the cost. Furthermore, as TVs and VTRs become smaller, there is a demand for smaller surface acoustic wave devices with smaller mounting areas.

In order to reduce costs and reduce the mounting area, research and development has been developed to seal the surface acoustic wave element in a hollow thermoplastic resin package instead of the conventional sealing structure consisting of a stem (2) and a metal shell (4). is in progress.

FIG. 6 shows a resin-packaged surface acoustic wave device in which a surface acoustic wave element is sealed with the thermoplastic resin package.

This surface acoustic wave device is made of thermoplastic resin package (6)
The island part (7) on which the surface acoustic wave element (not shown) is mounted and the base end (9a) of the lead (8) connected to each electrode of the surface acoustic wave element by bonding wires are in close contact with the inner bottom of the and the tip (9b) of the lead (8)
) side passes through the side wall of the resin package (6) in an airtight manner. The upper opening of the resin package (6) is airtightly covered with a resin lid (10).

In particular, in a DIP (Dual Pin Package) type surface acoustic wave device, the tip (9b) side of the lead (8) penetrating the resin package (6) is located close to the side surface of the resin package (6). It is bent.

Conventionally, such resin-packaged surface acoustic wave devices are manufactured by a resin molding method using a molding die, and the surface acoustic wave element is bonded to the island portion (7) of a lead frame in which the island portion and the leads are integrally molded. Then, each electrode is connected to the lead frame lead (
8), when molding a hollow thermoplastic resin package (6) using a molding die, an island part (7) and leads (
The base ends (9a) of the leads (8) are brought into close contact with each other, and the tips (9a) of the leads (8) are brought into close contact with each other from the side of the resin package (6).
b) Extend airtightly. After that, the upper opening of this resin package (6) is airtightly covered with a resin lid (10), and then the island part and the leads are separated from the frame part of the lead frame and further extended from the side surface of the resin package (6). It is manufactured by bending the tip end (9a) side of the lead (8).

By the way, resin-packaged surface acoustic wave devices are becoming more compact to reduce the mounting area, and at the same time, for example, for DIP type surface acoustic wave devices, the shape, size, arrangement pitch, etc. of the bins are changed for mounting reasons. DI of the semiconductor device shown in
It is more convenient to use the same pin as the P-type pin (11). In this case, the width of the tip (9b) of the lead (8) extending from the side surface of the resin package is the same as that of the conventional SIP (Sin
It is wider than the surface acoustic wave device of the GLE Inline Package type, and needs to be bent at a position close to the side surface of the resin package as described above.

This bending is usually done by press working.

As a result, thermoplastic resin packages have low mechanical strength, and the stresses generated by the bending of the wide leads near their sides can cause chips and cracks to occur in the resin package. In addition to damaging the airtightness within the resin package, there is a risk that moisture from the atmosphere may enter and deteriorate the characteristics of the surface acoustic wave element.

(Problems to be Solved by the Invention) As described above, in order to reduce the cost and the mounting area of surface acoustic wave devices, surface acoustic wave elements are hermetically sealed with thermoplastic resin packages. In this resin-packaged surface acoustic wave device, after the resin package is integrally molded with the lead frame on which the surface acoustic wave element is mounted, especially in DIP type surface acoustic wave devices, the resin package is extended from the side of the resin package. The tip of the protruding lead is bent by press processing at a position close to the side surface of the resin package. Therefore, the stress generated by this bending is applied to the thermoplastic resin package, which has low mechanical strength, which not only causes chips in the resin package and impairs its appearance, but also impairs the airtightness within the resin package and allows moisture in the atmosphere to escape. There is a risk that the characteristics of the surface acoustic wave element may be deteriorated due to the intrusion of such substances.

The present invention has been made to solve the above-mentioned problems, and provides a resin-packaged surface acoustic wave device with a structure in which the resin package will not be chipped even if the leads are bent near the resin package. With the goal.

[Structure of the Invention] (Means for Solving the Problems) A surface acoustic wave device having a predetermined pattern of electrodes formed on a substrate, an island portion on which the surface acoustic wave device is mounted, and a surface acoustic wave device connected to the electrodes of the surface acoustic wave device. In a surface acoustic wave device in which the proximal end of the lead is in close contact with the inner bottom of a resin package, a notch or a narrow part is provided on the distal end of the lead that airtightly penetrates the resin package and is located outside of the resin package. A structure was formed in which the leads were bent at this notch or narrow width.

(Function) As mentioned above, if a notch or narrow width part is provided on the tip end side of the lead that penetrates the resin package and is located outside of the resin package, and the lead is bent at this notch or narrow width part. , the stress when bending the lead can be concentrated in the notch or narrow part with low mechanical strength, and compared to conventional leads, it can be bent with a smaller bending load, reducing the stress applied to the resin package. can be made smaller.

(Example) Hereinafter, the present invention will be described based on an example with reference to the drawings.

FIG. 1 shows a surface acoustic wave device that is one embodiment of the present invention. This surface acoustic wave device is a DIP type surface acoustic wave device, and a surface acoustic wave element (not shown) is mounted on the inner bottom of a package (20) made of a thermoplastic resin such as liquid crystal polymer or polyphenylene sulfide. Island part (
21) and the base end (23a) of the lead (22) connected to each electrode of the surface acoustic wave element by a bonding wire.
) sides are in close contact, and the tip (23b) of the lead (22)
The side of the resin package (20) hermetically passes through the side wall of the resin package (20) and extends to the outside.

In addition, the upper opening of the package (20) is made of a resin lid (24).
) is formed into an airtight structure.

Moreover, in this surface acoustic wave device, the resin package (2
An arc-shaped notch (25) is formed from both sides at a position close to the outer surface of the resin package (20) at the tip (23b) of the lead (22) that airtightly penetrates the side wall of the lead (22). It is bent at the part where the notch (25) is formed. The depth S of this notch (25) is preferably set to such a size that the lead (22) is not cut.For example, for a lead whose tip end (23b) has a width W of 1 inch, the depth S is 0.
It is preferable to form it to a thickness of about 4 to 0.8 mm.

As shown in FIGS. 2 and 3, in this surface acoustic wave device, when the lead frame (27) in which the island portion (21) and the leads (22) are integrally formed is formed in advance, the leads (22) ) with a notch (25
), and after molding the resin package (20) by the resin molding method using a molding mold in the same way as in the manufacture of conventional resin packaged surface acoustic wave devices, the side walls of the resin package (2D) are made airtight. Penetrating lead (22)
The tip (23b) side of the notch (2
5) Manufactured by bending at the forming part.

By the way, when the surface acoustic wave device is configured as described above,
Even if the tip end (23b) of the lead (22) extending from the side wall of the resin package (20) is bent at a position close to the outer surface of the resin package (20) after molding, the problem may occur due to bending. A notch with low mechanical strength (2
5) The stress applied to the resin package (20) can be reduced by concentrating it on the forming part.

Therefore, it is possible to prevent the thermoplastic resin package (20), which has low mechanical strength, from chipping due to bending of the leads (22). Without compromising sexuality,
A highly reliable surface acoustic wave device that maintains required characteristics can be manufactured with high yield.

In the above embodiment, arc-shaped notches were formed on both sides of the lead, but these notches may be triangular notches (25) shown in FIG. 4(a) or any other polygonal shape. Alternatively, as shown in FIG. 6(b), the bent portion may be formed with a narrow portion (28) narrower than the adjacent portion.

Furthermore, in the above embodiment, a DIP type surface acoustic wave device was described, but the present invention is directed to a Z-type surface acoustic wave device having a bending pin.
It is also applicable to surface acoustic wave devices such as IP (Sig Zag Inline Pin) type.

C Effect of the invention] The base end side of the lead connected to the island part on which the surface acoustic wave element is mounted and the electrode of the surface acoustic wave element airtightly penetrates the resin package that is in close contact with the inner bottom part, and the lead is located outside of the resin package. By providing a notch or narrow width part on the tip side of the lead, and bending the lead at this notch or narrow width part, the lead can be bent with a small bending load, and the stress applied to the resin package can be reduced. can. therefore,
After the resin package is molded, even if the tip end of the lead is bent close to the outer surface of the resin package, it can be easily bent without causing chips or cracks in the resin package, and the appearance quality and characteristics are not impaired. A resin packaged surface acoustic wave device with the required high reliability can be obtained.

[Brief explanation of drawings]

Figures 1 to 4 are detailed explanatory diagrams of this invention.
Figures (a) to C) are partially cutaway plan views, front views, and side views showing the structure of a resin-packaged surface acoustic wave device, which is an example of the same, and Figure 2 is a diagram showing the structure of the surface acoustic wave device. A plan view showing the structure of a lead frame used in manufacturing, FIG. 3 is a diagram showing notches formed in the leads of the lead frame, and FIGS. 4 (a) and (6) respectively show notches formed in the leads of the lead frame. FIG. 5 is a partially cutaway perspective view showing the configuration of a conventional metal package surface acoustic wave device;
6(a) to 6(c) are plan views, front views, and side views showing the pin arrangement of a DIP type semiconductor device, respectively, and FIG. FIG. 2 is a partially cutaway plan view, front view, and side view of the configuration of the device. 20... Resin package 21... Island part 2
2...Lead 23a...Lead base end 23b...Lead tip end 25...Notch 27...Lead frame 28...Narrow width part

Claims (1)

[Scope of Claims] A surface acoustic wave device having a predetermined pattern of electrodes formed on a substrate, an island portion on which this surface acoustic wave device is mounted, and a plate whose base end portion is connected to the electrode of the surface acoustic wave device. a resin package, the island portion on which the surface acoustic wave element is mounted, and a resin package in which the proximal end side of the lead is brought into close contact with the inner bottom portion, and the distal end side of the lead is hermetically penetrated; A notch or a narrow part is provided on the tip end side of the lead that airtightly penetrates the resin package and is located outside the resin package, and the lead is bent at the notch or narrow part. A surface acoustic wave device characterized by: