JPH09232899A - Package mount method for electronic element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a package with a simple process and sure electric connec tion by connecting an electronic element to an inner electronic via a 1st connec tor and fixing a cover to the package main body via a 2nd connector. SOLUTION: A 2nd connector 7 is formed in a square ring along a circumferential ridge in an inner face of a cover 4 by, e.g. an Au-Sn alloy, an adhesive 6 is applied to the middle of the inner face and an electronic element 1 is adhered. The cover 4 is placed on a circumferential wall 3a of the package main body 3 to bring the 1st connector 1a of the electronic element 1 into contact with an electrode wire in the package main body 3 and the 2nd connector 7 provided to the cover 4 is brought into contact with an upper end of a circumferential wall 3a of the package main body 3. The element is loaded into a furnace, kept therein at a prescribed temperature and cooled or left as it is, then the 1st and 2nd connectors 1a, 7 are molten and the electronic element 1 is connected electrically to an electrode wire 5b via the 1st connector 1a and the cover 4 and the package main body 3 are fixed via the 2nd connector 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package mounting method for electronic devices, in which electronic devices are hermetically sealed in a package.

[0002]

2. Description of the Related Art Various electronic devices such as ICs are used in a state where they are sealed or housed in various packages for the purpose of protecting them from the influence of external force, heat, pollution or the like from the outside. . In particular, the surface acoustic wave element is housed in a state where the surface is open because of the property of transmitting electric signals in the high frequency band by utilizing the propagation of so-called surface acoustic waves propagating on the surface of a solid body such as a piezoelectric body. It is mounted and used in electronic circuits such as substrates in the form of packages.

As this type of package, for example, Japanese Patent Laid-Open No. 63-314908 discloses a conventional general structure of a surface acoustic wave device. According to this description, FIG.
As shown in (a), the surface acoustic wave device 23 is fixed on the back surface side of the metal base 22 provided with the lead electrodes 21 and 21 with an adhesive 24, and the surface acoustic wave device 2
The element electrodes provided on the front surface side of No. 3 and the corresponding lead electrodes 21, 21 are electrically connected via the gold wires 25, 25 by wire bonding.

The surface acoustic wave device 23 is hermetically sealed with its surface open by mounting a metal cap 26 for sealing on the base 22 after such electrical wiring is provided. It is housed in a space defined between the base 22 and the cap 26. On the other hand, a surface acoustic wave device 30 is fixed on the back surface side with an adhesive 29 in a ceramic package body 28 in which an internal space 27 composed of a concave surface on which internal wiring (not shown) is patterned is provided. By connecting the internal wiring of the package body 28 and the element electrode of the surface acoustic wave element 30 via the wiring 31, 31 by wire bonding, the lid 32 is fixed to the package body 28 by the bonding agent 33. A method of fixing the surface acoustic wave element 30 in the internal space 27 in a sealed state is also known.

[0005]

A surface acoustic wave device is usually provided with about 4 to 6 external connection electrodes on the surface of the device, and its electrical connection is performed by wire bonding in a number corresponding to the number of external connection electrodes. Wiring is applied. However, Figure 4
In the method shown in (a), one electronic element 24 is wire-bonded with a plurality of wires, that is, four wires, which complicates the wiring process. Further, it is known that when wiring is performed by wire bonding, wiring failure inevitably occurs at a certain rate. However, when wire bonding wiring is used at a plurality of locations as in the conventional method, bonding is not possible. The rate of occurrence of defects must be increased accordingly.

On the other hand, in the method shown in FIG. 4 (b), although the structure is simplified in that the internal wiring is integrally provided on the package body 28 itself, the wire bonding wirings 31, 31 are provided. However, it is still used in multiple places. Further, the package body 28 has a recessed internal space 27.
The electronic device 30 must be placed exactly inside. Therefore, it is an object of the present invention to obtain a package mounting method for an electronic element that can more surely perform electrical connection and package sealing in a simpler process.

[0007]

In order to solve the above problems, a package mounting method for an electronic device according to the present invention comprises a package body having an internal space defined by a recess having an internal electrode formed on the surface thereof, A lid formed so as to be attachable to the package body and an electronic element having a first connection body formed on the front surface are prepared, the electronic element is attached to the lid on the back surface, and the lid is bonded. It is placed on the package body via the second connecting body as a material, and then the electronic element is connected to the electrode wiring via the first connecting body and the lid body is fixed to the package body via the second connecting body. It is characterized by consisting of

Therefore, according to the method of the present invention, it is possible to obtain a package body which is more surely electrically connected in a simpler process. The package mounting method of the present invention is the first
The connection via the connecting body and the fixing via the second connecting body can be performed in the same step. With this configuration, the connection by the first connecting body and the fixing by the second connecting body can be performed at the same time.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a package mounting method for an electronic device according to the present invention will be described in detail with reference to the drawings. An electronic element formed by the package mounting method of the present invention is shown in FIG. The electronic element is, for example, as shown in FIG. 1, a surface acoustic wave element 1, and a ceramic package body 3 provided with an internal space 2 defined by a recess in which the surface acoustic wave element 1 is housed. And a lid 4 mounted on the package body 3 so as to close the internal space 2 accommodating the surface acoustic wave element 1.

The surface of the surface acoustic wave element 1 through which the surface acoustic wave propagates is shown as a downward surface in FIG. 1. On this surface, there are left and right comb-teeth-shaped element electrodes (not shown) that mesh with each other. There are a total of four on each side. Conductive bumps 1a, 1a (only two of which are located in front of the paper in FIG. 1 are shown) are formed correspondingly to these element electrodes as a first connecting body for external connection. There is. The first connector 1a, 1a is, for example, Au-Sn.
It is formed of an alloy.

The package body 3 is also integrally formed with electrode wirings 5 and 5a led out to the lower surface side thereof. As shown in the plan view of the package body 3 in FIG. 2, each electrode wiring 5 is formed to extend inside and outside the package body 3 via a peripheral wall 3a and an end wall 3b formed by a through hole technique. There is. Here, the surface acoustic wave element 1 will be described again with reference to FIG. 1. The back surface of the surface acoustic wave element 1 is fixed to the inner surface of the lid body 4 with the adhesive 6. The bumps 1a, 1a of the surface acoustic wave device 1 are electrically connected to the electrode wirings 5, 5 inside the package body 3, while the lid body 4 has a second connecting body 7 at a peripheral portion of its inner surface. It is fixed to the peripheral wall 3 a of the package body 3. The second connection body 7 can be formed of, for example, the same Au—Sn alloy as that used for the first connection bodies 1a and 1a.

Next, a package mounting method of the electronic device of the present invention will be described. First, a box-shaped ceramic package body with an open space defined inside, a Kovar lid that can be attached to the package body to close the internal space, and a conductive surface. Material,
For example, a surface acoustic wave element as an electronic element having a bump as a first connection body made of an Au-Sn alloy is prepared. The first electronic element to be stored in the package body
Electrode wiring is formed in advance so as to correspond to the connection body, and a refractory metal layer is provided on the upper end of the peripheral wall 3a through a high melting point metal layer.
A plated layer of u and Ni is formed. .

At the time of these preparations, as shown in FIG. 3A, the second connecting body 7 is formed along the peripheral edge of the inner surface of the lid 4 in the shape of a square ring of, for example, an Au--Sn alloy.
At the center of the inner surface where the second connecting body 7 is formed,
As shown in FIG. 3B, the adhesive 6 is applied using, for example, a dispenser, and the electronic element 1 is attached on the back surface thereof. The surface of the electronic element 1, that is, the surface on which the first connection body 1a is provided faces upward. As the adhesive 6, for example, a thermosetting adhesive can be easily used.

After the electronic element 1 is attached, as shown in FIG. 3C, the lid 4 is placed on the peripheral wall 3a of the package body 3 so that the electronic element 1 is housed in the internal space of the package body 3.
Place on top. By mounting the lid body 4, the first connection body 1a of the electronic element 1 abuts on the electrode wiring in the package body 3, and the second connection body 7 provided on the lid body 4 is attached to the peripheral wall 3a of the package body 3. Is in contact with the upper end of.

As described above, the lid 4 is placed on the package body 3 and then placed in a heating furnace. The temperature is kept at about 280 ° C. for about several seconds and then cooled or left to stand for the first and the second. The connection bodies 1a and 7 are melted, and the electronic element 1 is connected to the electrode wiring 5 through the first connection body 1a as shown in FIG.
While being electrically connected to b, the lid 4 and the package body 3 are fixed via the second connecting body 7.

In this case, since the second connecting body 7 is formed in advance in the shape of a square ring along the peripheral edge of the lid body 4, it is fused to the package body 3 by melting and the package 3 in which the electronic element 1 is housed. The internal space 2 is sealed from the outside in an airtight manner. The package body thus obtained can be mounted and used by electrically connecting it to a circuit formed on the surface of the substrate or the like through the electrode wiring led to the outside of the package body.

[0017]

As described above in detail, according to the package mounting method of the electronic device of the present invention, the package body having the internal space defined by the recess having the internal electrode formed on the surface thereof, and the package A lid formed to be attachable to the main body and an electronic element having a first connection body formed on the surface are prepared, and the electronic element is attached to the lid on the back surface thereof.
Place the lid on the package body via the second connector,
Next, since the electronic element is connected to the internal electrode via the first connection body and the lid body is fixed to the package body via the second connection body, more reliable electrical connection can be achieved by a simpler process. An applied package body can be obtained.

Therefore, according to the method of the present invention, it is possible to obtain a package body which is more surely electrically connected in a simpler process. The package mounting method of the present invention is the second
The connecting body may be configured such that the same material as that of the first connecting body is the main component and the connection through the first connecting body and the fixing through the second connecting body are performed in the same step.

With this structure, the connection by the first connecting body and the fixing by the second connecting body can be performed at the same time.

[Brief description of drawings]

1 is a cross-sectional view of a package structure according to the method of the present invention.

FIG. 2 is a plan view of a package body having the package structure of FIG.

FIG. 3 is a diagram showing main steps of a package mounting method of the present invention.

FIG. 4 is a cross-sectional view showing a conventional package structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic element 1a 1st connection body 2 Internal space 3 Package body 4 Lid body 5 Electrode wiring 6 Adhesive 7 Second connection body

Claims (4)

[Claims] 1. A package main body having an internal space defined by a recess having electrode wiring formed on the surface, a lid body mountable on the package main body, and a first connecting body formed on the surface. And the electronic element is attached to the lid body at the back surface thereof, and the lid body is
Mounted on the package main body via the connection body, then the electronic element is connected to the electrode wiring via the first connection body, and the lid body is connected to the package main body via the second connection body. A package mounting method for an electronic device, comprising: fixing to an electronic device. 2. The connection through the first connection body and the second connection
The package mounting method according to claim 1, wherein the fixing through the connecting body is performed in the same step. 3. The package mounting method according to claim 1, wherein the second connection body is provided on the lid body prior to placing the lid body on the package body. 4. The connection through the first connecting body and the second
The package mounting method according to claim 1, wherein the fixing through the connection body is performed by reflow by heating the first and second connection bodies.