JP2002299499A - Electronic component and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component where an element and input and output electrodes are connected with a sufficient strength, and its manufacturing method. SOLUTION: A package 11 having input and output electrodes 12, a ground electrode 15, and electrode nonforming parts 16a, 16b, 16c and 16d is formed on the inner bottom face. On the other hand, an SAW element 17 having an IDT17b and a connection electrode 17c on a piezoelectric substrate 17a is obtained and a bump 18 is formed on the connection electrode 17c. Image of the package 11 is then picked up from the upper surface thereof, intersections of the extension of respective sides of the electrode nonforming parts 16a and 16b, 16c and 16d are detected and mounting position of the SAW element 17 is determined from the intersections and the inner circumferential shape of the package 11. Subsequently, the SAW element 17 is contained in the package 11, the bump 18 is bonded to the input and output electrodes 12 by applying an ultrasonic wave from the rear of the SAW element 17 and the opening of the package 11 is sealed by a rid 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electronic component having elements housed in a package, such as a SAW device, and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 4 is a top view of a conventional package, and FIG.
Is a top view of a conventional SAW device before sealing with a lid, and FIG. 6 is a sectional view of the conventional SAW device.

In FIG. 1, reference numeral 1 denotes a package formed by using alumina or the like, 2 denotes an input electrode formed on the inner bottom surface of the package 1 by using gold, and 3 denotes a ground electrode formed on the inner bottom surface also by using gold. Reference numeral 4 denotes a SAW element having an interdigital transducer (hereinafter referred to as IDT) and a connection electrode on its surface. Reference numeral 5 denotes a gold bump connecting the connection electrode of the SAW element 4 to the input and output electrodes 2. Reference numeral 6 denotes an opening of the package 1. A lid for sealing the part.

[0004] A method of manufacturing the SAW device thus formed will be described.

[0005] First, an output electrode 2 and a ground electrode 3 are formed on a substrate surface serving as a bottom surface of the package 1. Next, a frame body serving as a side surface of the package 1 is laminated on this substrate, and is integrated by firing, thereby obtaining the package 1.

On the other hand, the IDT and this I
The SAW element 4 having the connection electrode connected to the DT is formed.

Next, a bump 5 is formed on the connection electrode of the SAW element 4.
To form

Next, the mounting position of the SAW element 4 is determined based on the inner peripheral dimension of the package 1 as shown in FIG. 4, and the bump 5 is inserted into the output electrode 2 to thereby mount the SAW element 4 in the package 1. I do.

Then, the opening of the package 1 is
Seal with.

[0010]

According to this configuration, when the package 1 is manufactured, if the frame is misaligned, the package can be mounted with high accuracy when viewed from the top as shown in FIGS. However, since the input and output electrodes 2 are also misaligned, the bumps 5 are joined at the ends of the input and output electrodes 2 instead of at the center. The ends of the input and output electrodes 2 are not uniform in thickness, and become thinner toward the ends. Therefore, there is a problem that if the bonding is performed at the ends of the input and output electrodes 2, a sufficient connection strength between the SAW element 4 and the input and output electrodes 2 cannot be secured.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electronic component on which elements can be mounted with high precision so as to be able to be connected to input and output electrodes with sufficient strength, and a method for manufacturing the same.

[0012]

In order to achieve this object, the present invention has the following arrangement.

[0013] The invention described in claim 1 of the present invention is, in particular,
An electrode non-forming part for mounting and positioning the element is provided so as to be in contact with the two sides on the inner bottom surface of the package.The mounting position of the element is precisely adjusted so that sufficient connection strength between the element and the input and output electrodes can be obtained. You can make a good decision.

[0014] The invention described in claim 2 of the present invention is, in particular,
The electrode non-formed portion is provided at least two so as to be in contact with two adjacent sides, respectively, and it is possible to accurately determine the mounting position of the element so that sufficient connection strength between the element and the input and output electrodes is obtained. it can.

[0015] The invention described in claim 3 of the present invention is, in particular,
The width of the electrode-free portion in the direction between the inner peripheral end of the package and the element is equal to or smaller than (distance between the inner peripheral end of the package−the width of the element) / 2. In consideration of the mounting accuracy of the device, the mounting position of the device can be accurately determined so that a sufficient connection strength between the device and the input / output electrodes can be obtained.

The invention described in claim 4 of the present invention particularly provides
The non-electrode-formed portion has a different shape, and can be reliably mounted even when the element has directionality.

According to a fifth aspect of the present invention, a mounting position of an element is determined by using an electrode-free portion provided on an inner bottom surface, and a sufficient connection between the element and input and output electrodes is provided. The mounting position of the element can be accurately determined so that the strength is obtained.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a first embodiment of the present invention;

FIG. 1 is a top view of a SAW device as an example of an electronic component before package encapsulation in one embodiment of the present invention, FIG. 2 is a top view of a package in one embodiment of the present invention, and FIG. 1 is a sectional view of a SAW device according to an embodiment of the present invention.

In the figure, reference numeral 11 denotes a package formed using ceramics such as alumina, 11a denotes a substrate constituting the package 11, 11b denotes a frame provided on the substrate 11a, and 12 denotes a package provided on the inner bottom surface of the package 11. , An output electrode, 13 is an external electrode provided on the outer bottom surface of the package 11, 14 is a through electrode connecting the input and output electrodes 12 and the external electrode 13, 15 is a ground electrode provided on the inner bottom surface of the package 11, 16a, 16b, 16c, 16d are electrode non-forming portions provided on the inner bottom surface of the package 11, 17a
Is a piezoelectric substrate formed using a single crystal such as lithium tantalate or lithium niobate, 17b is an IDT provided on the surface of the piezoelectric substrate 17a, 17c is a connection electrode connected to the IDT 17b, and 17 is 17a to 17c. SAW element, 18 is a bump formed of a conductor such as gold for connecting the connection electrode 17c to the input and output electrodes 12, 19 is a lid for sealing the opening of the package 11, 20 is the package 11 and the lid. 19 is a solder for connecting.

A method for manufacturing a SAW device having such a configuration will be described below.

First, the input and output electrodes 12 and the ground electrode 1 to be formed on the front, back and inside of the substrate 11a
5. Same plating base layer and through electrode 14 as external electrode 13
To form

Next, the frame 11b is arranged on the substrate 11a and baked to integrate the substrate 11a and the frame 11b to produce the package 11. Here, the substrate 11a and the frame 11
b is mainly composed of aluminum oxide, the plating base layer is mainly composed of tungsten, and the through electrode 14 is formed using tungsten.

Thereafter, nickel plating is performed on the plating base layer of the package 11 and then gold plating is performed.
The output electrode 12 and the ground electrode 15 are formed.

As can be seen from FIG. 1, the input and output electrodes 12 are formed at opposite ends on the inner bottom surface of the package 11.

The inner bottom surface of the package 11 is substantially rectangular or substantially square, and each side is parallel to each side of the package 11 and has the same shape as the lower end of the inner periphery of the frame 11b. That is, the non-electrode-formed portions 16a, 16b, 16c, and 16d are also substantially rectangular or substantially square, and one side is on the same line as one side of the internal bottom surface.

Further, adjacent electrode non-forming portions 16a, 16
b, 16c and 16d are formed as far away as possible.

Further, the width (d1 in FIG. 1) of the electrode non-formed portions 16a and 16c in the direction between the package 11 and the SAW element 17 to be mounted later is represented by [Distance between inner peripheral ends of the package 11 (K1 in FIG. 1)]. ) -Width of SAW element 17 (L in FIG. 1)
1)] / 2, and the width (d2 in FIG. 1) of the electrode non-formed portions 16b and 16d in the direction between the package 11 and the SAW element 17 to be mounted later (d2 in FIG. 1). K2) -Width of SAW element 17 (L2 in FIG. 1)]
/ 2.

Further, the electrode non-formed portions 16a, 16b,
16c and 16d are all different sizes.

On the other hand, the input and output I
Forming a DT 17b and a connection electrode 17c to form a SAW element 17;
Get. Further, a bump 18 is formed on the connection electrode 17c.

Next, the package 11 is image-recognized from the upper surface, and at least two intersections of the extension lines of the sides of the bottom surfaces inside the package 11 of the electrode non-formed portions 16a and 16b and 16c and 16d are checked out. The mounting position of the SAW element 17 is determined from the shape of the bottom surface and the shapes of the electrode non-formed portions 16a, 16b, 16c, 16d.

Next, the SAW element 17 is housed in the package 11, the ultrasonic wave is applied from the back surface of the SAW element 17 to the bump 18, and the output electrode 12 is joined.

After that, the lid 19 is connected to the upper end surface of the package 11 via the solder 20, so that the SAW
The element 17 is sealed in the package 11 to obtain a SAW device.

Although the conventional SAW device appears to be mounted with high accuracy when viewed from the top surface of the package 1 as shown in FIG. 5, the positions of the input and output electrodes 2 and the ground electrode 3 on the inner bottom surface are not changed. If they are shifted, the ends of the input and output electrodes 2 are joined to the bumps 5. Input and output electrodes 2
Since the thickness of the end portion becomes gradually thinner, the connection with the bump 5 cannot be made firmly.

However, the SAW device according to the present embodiment has the electrode non-formed portions 16a, 16b, 16c, 16d.
Is used to position the SAW element 17,
Even if the formation positions of the input electrode 12 and the ground electrode 15 are shifted with respect to the inner peripheral shape of the package 11,
At the same time, the electrode non-formed portions 16a, 16b, 16c, 16
Since the position d is also displaced, the bump 18 can be securely bonded to a stable place of the input and output electrodes 12.

As described above, in the SAW device of the present embodiment, the SAW element 1 is formed by the electrode non-formed portions 16a, 16b, 16c, 16d provided on the inner bottom surface of the package 11.
7 can be accurately mounted, so that the input and output electrodes 1
The electrical connection between the bump 2 and the bump 2 can be reliably established, and the mounting accuracy of the SAW element 17 can be confirmed only by recognizing an image from the upper surface of the package 11 without performing X-ray fluoroscopy or the like.

The electrode non-formed portions 16a, 16b, 16
Since c and 16d are provided such that one side thereof is on the same line as the side of the inner bottom surface of the rectangular package 11, the electrode non-formed portions 16a and 16b provided on adjacent sides are provided.
The mounting position of the SAW element 17 can be accurately determined from the intersection of the extension lines of the sides of the inner bottom surface of the package 11 of 16c and 16d and the inner peripheral dimension of the package 11.

Further, the inner peripheral end of the package 11 and the SAW
Electrode non-formed portions 16a, 16b, 16 in the direction between elements 17
The widths of c and 16d are determined by (distance between inner peripheral ends of package 11 −
It is desirable that the width is equal to or smaller than (the width of the SAW element 17) / 2. In the same case, when the ends of the SAW element 17 and the ends of the electrode non-formed portions 16a, 16b, 16c, and 16d are mounted in substantially the same straight line, the bumps 18 can be inserted and bonded to the output electrode 12 at a stable position. . If the SAW element 17 is mounted, the left and right electrode non-formed portions 16a, 16b, 16c, and 16d sandwich the SAW element 17 when viewed from above after mounting.
By making the widths of the bumps the same, the bumps 18 can be formed and bonded to the output electrode 12 at a stable position. That is, the electrode non-formed portions 16a, 16b, 16c, 16d are SA
It is not hidden by the W element 17. When the width is reduced, it is desirable to reduce the width in accordance with a mounting error of a mounting machine on which the SAW element 17 is mounted.

Furthermore, when the mounting position of the SAW element 17 has a direction, the electrode non-formed portions 16a, 16b, 16
By changing the sizes of c and 16d, it is possible to prevent an error in the mounting direction from occurring.

The mounting position of the SAW element 17 is determined by using the electrode non-formed portions 16a, 16b, 16c and 16d provided on the inner bottom surface of the package 11, so that the SAW element 17 can be mounted with high accuracy. it can.

The non-electrode forming portions 16a, 16c, 16
By setting the widths of b and 16d in the direction between the package 11 and the SAW element 17, the input and output electrodes 12 and the bumps 18 can be securely bonded.

In order to improve the mounting accuracy of the SAW element 17, the electrode non-formed portions 16a, 16b, 16c, 16
Four d were formed. However, if there are two adjacent sides of the inner bottom surface of the package 11 and the non-electrode-formed portion in which one side is on the same straight line, the positioning of the SAW element 17 can be performed with higher accuracy than in the past. Although four or more may be formed, the ground electrode 15 becomes smaller by that amount, so that it is desirable to minimize the number.

Further, in the above embodiment, the SAW
Although the device has been described as an example, the same effect can be obtained in an electronic component mounted on a package having an output electrode and a ground electrode on the inner bottom surface such that the front surface side of the element is located below.

[0044]

As described above, according to the present invention, the device can be mounted with high accuracy by providing at least two non-electrode forming portions for mounting and positioning the device on the inner bottom surface of the package.

[Brief description of the drawings]

FIG. 1 is a top view of a SAW device before sealing with a lid according to an embodiment of the present invention.

FIG. 2 is a top view of a package according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a SAW device according to one embodiment of the present invention.

FIG. 4 is a top view of a conventional package.

FIG. 5 is a top view of a conventional SAW device before sealing with a lid.

FIG. 6 is a cross-sectional view of a conventional SAW device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Package 11a Substrate 11b Frame 12 Input / output electrode 13 External electrode 14 Through electrode 15 Ground electrode 16a Electrode non-forming part 16b Electrode non-forming part 16c Electrode non-forming part 16d Electrode non-forming part 17 SAW element 17a Piezoelectric substrate 17b IDT 17c Connection electrode 18 Bump 19 Lid

Claims (5)

[Claims] 1. A package having an input electrode, an output electrode, and a ground electrode on an inner bottom surface, an element mounted inside the package, and a conductor electrically connecting the element to the input and output electrodes. An electronic component provided with an electrode non-forming portion for mounting and positioning the element so as to be in contact with two sides of the inner bottom surface. 2. The electronic component according to claim 1, wherein at least two non-electrode forming portions are provided so as to be in contact with two adjacent sides, respectively. 3. The width of the electrode-free portion in the direction between the inner peripheral end of the package and the element is equal to or smaller than (distance between the inner peripheral end of the package−the width of the element) / 2. The electronic component according to claim 1. 4. The electronic component according to claim 1, wherein the non-electrode-formed portions have different shapes. 5. A first step of mounting an element on a package having an input electrode, a ground electrode, and an electrode-free portion on an inner bottom surface, and a second step of sealing an opening of the package. A method of manufacturing an electronic component, wherein the mounting position of the element in the second step is determined using the non-electrode-formed portion.