CN2497487Y

CN2497487Y - Ceramic packing case of surface acoustic wave device

Info

Publication number: CN2497487Y
Application number: CN 01262927
Authority: CN
Inventors: 王建文; 刘平
Original assignee: Shoulder Electronics Co Ltd
Current assignee: Shoulder Electronics Co Ltd
Priority date: 2001-09-21
Filing date: 2001-09-21
Publication date: 2002-06-26
Anticipated expiration: 2011-09-21

Abstract

The utility model relates to a ceramic packaging shell of a surface acoustic wave device, by adopting the utility model, a pipe core of the surface acoustic wave device can be packaged under the normal temperature to avoid the harm to the performance of the pipe core when being sintered under the high temperature. With the simple packaging techniques, the utility model consists of a ceramic base and a top cover, an external surface of the base is provided with outer lead wires, an inner electrode which is conductively connected with the outer lead wires is arranged in the interior of the base, the utility model is characterized in that a certain geometrical height is kept between the position of the inner electrode and the position opposite to the inner bottom surface of the base. The conductive connection structure between the inner electrode and the outer lead wires consists of at least two layers of structures.

Description

The ceramic packaging shell of SAW (Surface Acoustic Wave) device

(1). technical field: the utility model belongs to the package casing of electronic devices and components, is specifically related to the ceramic packaging shell of SAW (Surface Acoustic Wave) device.

(2). background technology: the ceramic packaging shell of existing SAW (Surface Acoustic Wave) device, form the interior electrode that installs outer lead and become conduction to be connected on the base with outer lead by ceramic base and ceramic loam cake.Outer lead and interior electrode are made by the method for silk screen printing thin metal layer, are printed on the outer surface and the inner surface of base respectively.Conduct electricity between interior electrode and the outer lead and be connected.Said base is a tabular, loam cake is the fovea superior cover cap, the middle position silk screen printing thin metal layer of base inner surface, electrode in the silk screen printing as mentioned above all around, tube core is sintered on the thin metal layer of base inner surface middle position, is connected lead between tube core and interior electrode, starch at the periphery coating low-melting glass of base inner surface then, the ceramic cover cap of fovea superior is placed on the base, is that 370～380 ℃ of left and right sides sintering seal in temperature, so finishes the encapsulation of surface device.Typical products such as U.S.'s SAW (Surface Acoustic Wave) device that this ceramic packaging structure is used, model is: the RFM-315 type.The major defect of this kind ceramic packaging shell is in the encapsulation of 370～380 ℃ temperature sintering, all can cause certain infringement to the quality of SAW (Surface Acoustic Wave) device tube core performance and lead pressure welding point, reduces rate of finished products.Secondly, packaging technology complexity, technology cost height.

(3). summary of the invention: the purpose of this utility model is to solve the shortcoming of above-mentioned ceramic packaging shell, provides a kind of and can encapsulate at normal temperatures, the ceramic packaging shell of the simple SAW (Surface Acoustic Wave) device of packaging technology.The utility model comprises ceramic base and ceramic loam cake, base outer surface device outer lead, the interior electrode that device is connected with outer lead one-tenth conduction in the base, be characterised in that base becomes the shape of recessed housing, the position of the said interior electrode that is connected with outer lead one-tenth conduction has certain geometric height with respect to the position of base inner bottom surface.It is further characterized in that said in conductive structure of electrode and said outer lead constitute by two-layer at least, the conduction connecting line of said interior electrode and corresponding outer lead is by the side wall surface of base.

The beneficial effect of the relative background technology of the utility model is as follows:

At first, base of the present utility model becomes the shape of recessed housing, SAW (Surface Acoustic Wave) device is assemblied in housing bottom, so loam cake can be made frivolous flat board lid, at normal temperatures with epoxy resin can loam cake is firm the housing mouth that is bonded in base, realize normal temperature encapsulation down, avoid the high temperature encapsulation down to the infringement of tube core performance.And in background technology, the base of ceramic packaging shell is a tabular, and loam cake is the fovea superior cover cap, weight and volume are much bigger than base, be subjected to cold and hot or during external force stress big, as encapsulating with normal temperature epoxy, therefore the fastness that is difficult to remain potted has to adopt the high temperature sintering encapsulation.Secondly, tube core assembling of the present utility model is sintered in the inner surface of spill base bottom, the conduction connecting structure of electrode and said outer lead is made of two-layer at least in said, the position of interior electrode has certain geometric height with respect to the position of base bottom interior surface, make so to be connected with lead between the interior electrode to become easily that packaging technology is simple and easy to do in die surfaces.

(4). description of drawings:

Fig. 1 is vertical view of the present utility model (loam cake is opened);

Fig. 2 is a upward view of the present utility model;

Fig. 3 is elevational cross-sectional view of the present utility model (an A-A cutaway view among Fig. 1);

Fig. 4 is that cutaway view (B-B cutaway view among Fig. 1) is looked on a left side of the present utility model;

Fig. 5 is the conduction connecting structure figure of said interior electrode of the utility model ground floor and said outer lead;

Fig. 6 is the conduction connecting structure figure of said interior electrode of the utility model second layer and said outer lead.

(5). specific implementation method:

Accompanying drawings: see Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 6, the utility model comprises ceramic base 2 and ceramic loam cake 1, the base outer surface dress pastes

outer lead

9,14,24,25, the

interior electrode

23,18,4,21 that the corresponding one-tenth conduction with described outer lead of the interior arrangement of base 2 connects, from Fig. 3 or Fig. 4, find out the shape of 2 one-tenth recessed housings of base, in other words the low groove shape.11 is the chip of SAW (Surface Acoustic Wave) device among Fig. 1, Fig. 3, Fig. 4, and the conduction connecting line of above-mentioned

interior electrode

4,18,21,23 and chip 11 is respectively 3,19,20,22.Among Fig. 3 and Fig. 45,17,7 be respectively in the carriage of

electrode

4,18,23, the sidewall of itself and base 2 is connected as a single entity, interior electrode 21 also has the carriage with spline structure, does not cut open among the figure to illustrate.Among Fig. 3,13 is the outer lead identification mark, and 12 is the diapire of

base

2, and 8 for adorning the thin metal layer that is affixed on diapire 12 surfaces.27 is corresponding interior electrode identification mark among Fig. 1 and Fig. 5.

As seen, all there is certain geometric height the position of

interior electrode

4,18,23 with respect to base inner bottom surface 8 from Fig. 3, Fig. 4, and this height representative value is 0.5 millimeter, and other interior electrodes are in same level height among the height of interior electrode 21 and the figure, does not cut open among the figure to illustrate.Base 2 inner groovy height representative values are 1.5 millimeters, and the one-tenth-value thickness 1/10 of chip 11 is 0.4 millimeter.The thickness of thin metal layer 8 is the 3-5 micron, and is very thin, we can say that the position of base 2 inner bottom surfaces promptly is approximately the position on metal level 8 surfaces.

The distribution figure of each outer lead shown in Fig. 2, each outer lead corresponding expression in Fig. 1 and Fig. 5 is a dotted line.Find out that from Fig. 3, Fig. 4 interior electrode is made of two-layer with the conduction connecting structure of corresponding outer lead, it is the utility model preferred forms, and it also can be set to more than two-layer formation certainly.Among Fig. 3 and Fig. 58 is thin metal layers of printing with method for printing screen on base end face, is the ground floor of above-mentioned conduction connecting structure;

Interior electrode

4,18,21,23 among Fig. 6 also is the thin metal layer of printing with screen printing mode, it is the second layer of above-mentioned conduction connecting structure, see Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, between this two conductive layers with and with outer lead between realize that by

conduction connecting line

15,16,26,6 conduction is connected, specific practice is to punch between the thin metal layer of each conductive layer and corresponding outer lead, inject the metal slurry in the hole, be reduced to metal wire behind the sintering, thereby realize that conduction connects.It can also be seen that from Fig. 3, Fig. 4 electrode and the

conduction connecting line

6,16,26,15 of corresponding outer lead pass through the side wall surface of base 2 in each.From Fig. 2, Fig. 5 and Fig. 6 as can be seen,

interior electrode

18 and 23 connects by metal level 8 short circuits, and the

outer lead

14 and 9 that is connected with

interior electrode

18 and 23 one-tenths conductions also passes through metal level 8 short circuits connection;

Interior electrode

4 and 21 or corresponding

outer lead

24 and 25 mutually insulateds.Certainly, according to the tube core structure difference, interior electrode or outer lead also can be other conduction connecting structures, and Fig. 1 to Fig. 6 expresses a kind of specific implementation method of the present utility model.Can encapsulate at normal temperatures with epoxy resin between base 2 of the present utility model and the loam cake 1.Between loam cake 1 and the base 2 the different modes that covers can be arranged.

Claims

1. the ceramic packaging shell of SAW (Surface Acoustic Wave) device, comprise ceramic base and ceramic loam cake, base outer surface device outer lead, the interior electrode that device is connected with outer lead one-tenth conduction in the base, it is characterized in that base becomes the shape of recessed housing, the position of the said interior electrode that is connected with outer lead one-tenth conduction has certain geometric height with respect to the position of base inner bottom surface.

2. by the said ceramic packaging shell of claim 1, it is characterized in that said in the conduction connecting structure of electrode and said outer lead constitute by two-layer at least, the conduction connecting line of said interior electrode and corresponding outer lead is by the side wall surface of base.

3. by the said ceramic packaging shell of claim 2, it is characterized in that the conduction connecting structure of said interior electrode and said outer lead is made of two-layer.