CN1205809A

CN1205809A - Electronic component, esp. one operating with acoustic surface waves (OFW component) and process for its prodn.

Info

Publication number: CN1205809A
Application number: CN 96199159
Authority: CN
Inventors: W·帕尔; A·斯特泽尔; H·克吕格
Original assignee: Siemens Matsushita Components GmbH and Co KG
Current assignee: TDK Electronics AG
Priority date: 1995-12-21
Filing date: 1996-12-16
Publication date: 1999-01-20

Abstract

An OFW component with electrically conductive structures (3) on a substrate (1), sealed against environmental influences by a cap-like cover (2), on which there is a metallised coating (6) for HF screening.

Description

Electronic component uses the element-OFW element of surface acoustic wave work and the method for making this element especially

The present invention relates to a kind of electronic component and be particularly related to the element according to claim 1 preamble-OFW element of using surface acoustic wave work-and a kind of method of making this element.

Among the former German patent application P4415411.9; a kind of encapsulation that is used to have the electronic component of a cover has been described; this cover is sealed in a component structure on the substrate; one of them protective layer on substrate constitutes above-mentioned cover; in the component structure scope, protective layer has this receiving slit.Such protective layer protection component structure is not affected by environment, the electronic component of therefore such sealing-may not need other shell and directly can be for further use.

If such element constitutes and use glass solder to seal this shell for price reasons, can not provide an effective HF shielding so, because cover is constituted or do not existed the connection of shell conduction by pottery in ceramic package.Also there is this similar problem for plastic casing.

Based on task of the present invention is a kind of effective HF shielding that is used for mentioning under discussion the electronic component of type of explanation.

The feature by claim 1 characteristic solves according to the present invention in the electronic component of this task said type when a beginning.

A kind of method of this electronic component is made in explanation in

claim

3 and 4.

Be the theme of corresponding dependent claims not only about electronic component but also about the further structure of the method for making above-mentioned electronic component.

Next the form of implementation according to explanation in the accompanying drawings further specifies the present invention.

Among the figure:

One of Fig. 1 has a schematic diagram according to the OFW element of shielding of the present invention;

One of Fig. 2 is according to the part schematic diagram on the direction overlooked of the element of Fig. 1;

One of Fig. 3 has the part schematic diagram on the direction overlooked according to the OFW element of the suitable SMD assembling of HF of the present invention shielding;

One of Fig. 4 has the part schematic diagram on the direction overlooked according to the OFW element of the suitable flip-chip mounted of HF of the present invention shielding;

One of Fig. 5 has the part schematic diagram of the OFW element of multi-layer H F shielding.

According to Fig. 1, an OFW element generally comprises a Piezoelectric Substrates 1 and have conductive structure 3 on substrate, wherein for example may be related to the interdigital of interdigital transducer, resonator or reflector.Illustrated in the German patent application before mentioning as in beginning the time, conductive structure 3 is covered by a cover 2, and this this structure of cover protection is not affected by environment.This element uses protective layer 2 and substrate 1 can directly further use as " shell " or this element can be constructed in the enclosure.

Metal layer as the HF shielding is arranged on cover 2 according to the present invention, and the through hole 5 that this layer connects by a window 7 that passes on the cover 2 is connected surperficial 4-pad-conduction and connects with one.By this pad 4, the metal layer 6 that shields as HF can be connected with ground.

Fig. 2 explanation is according to the partial cross section of the element of the metal layer 6 with pad 4 and through hole 5 and covering surfaces of Fig. 1.

The metal layer 6 that constitutes the HF shielding can followingly constitute: at first evaporate the thin metal level of one deck and electroplate thickening subsequently on protective layer 2.

Also the sticking and film stack of metal layer 6 as conduction might be added on the protective layer 2 on the other hand.Sticking and film welds together with method and shell that does not explain that is fit to.

Fig. 3 illustrates the vertical view of a form of implementation of the element that a suitable SMD assembles.At this moment have a metal layer 8 that can weld on the surface according to the cover 2 of Fig. 1, this layer is connected with a pad 4 conductions by through hole 5.In order to separate, provide metal layer 6 as the HF shielding with these metal layer that can weld 8 electricity.

Fig. 4 illustrates the schematic diagram of a form of implementation of the OFW element that is fit to flip-chip mounted.In this form of implementation, wherein with form of implementation according to Fig. 1 in identical part have identical reference symbol, at window 7 bending 9 is arranged, crooked 9 on substrate surface and a pad that is not specifically noted weld together.By this crooked 9, can installation elements in a circuit.

Fig. 5 illustrates a form of implementation as the multilevel metallization layer of HF shielding, and this metal layer is the sequence of metal level, comprises the layer 11 of layer 10, nickel or copper formation that titanium/tungsten constitutes and the layer 12 that gold constitutes.At this moment the tack that guarantees on protective layer 2 of titanium and tungsten layer 10,11, nickel dam 12 guarantees weldabilities, gold layer 13 guarantees non-oxidizabilitys.The thickness of titanium and tungsten layer is preferably less than 0.1 μ m, and about 1 μ m of nickel layer thickness and golden layer thickness are approximately 0.1 μ m.

Valuable especially variation is the sequence of layer of evaporation titanium tungsten, copper or nickel and gold, their thickness and less than 10 μ m, preferably equal 0.3 μ m, by pulsed laser radiation with use the structure of this layer of copper currentless reinforcement formation.At this moment also generate through hole 5.Next for passivation, deposit the gold of 0.1 μ m thickness.

Because,, that is to say that for through hole of two element system be enough so can also arrange its position to make each throughhole portions always belong to an element system comprising generation through hole 5 on the backing sheet of a large amount of element system.

Can improve reliability by following way equally: make redundant through hole, that is to say that a pad has two through holes.

Claims

1, electronic component; special element-OFW the element that uses surface acoustic wave work; the conductive structure (3) that wherein provides on substrate (1) passes through a hood-shaped protective layer (2) sealed package in order to prevent environmental impact; a metal layer (6) is arranged on protective layer (2), by the window (7) on protective layer (2) by means of a through hole (5) with one Di be connected the surface (4)-pad-electrical connection.

3,, it is characterized in that metal layer (6) is made of the metal layer sequence of titanium/tungsten, copper or a nickel and gold (10,11,12,13) according to the electronic component of claim 1 or 2.

4, according to the electronic component of claim 3, the thickness that it is characterized in that titanium/nickel or copper is less than 0.1 μ m, the about 1 μ m of the bed thickness of nickel, the about 0.1 μ m of bed thickness of gold.

5, make method, it is characterized in that at first as metal level evaporated metal layer (6) and no current ground or electroplate thickened metalized layer (6) after this according to the electronic component of any in the claim 1 to 4.

6,, it is characterized in that generating metal layer (6), by the currentless thickening formation structure of pulsed laser radiation and use copper by the sequence of layer that evaporates titanium tungsten, copper or a nickel and gold according to the method for claim 5.

7, make method, it is characterized in that sticking and film stack metal layer as conduction according to the electronic component of any in the claim 1 to 4.

8,, it is characterized in that sticking and film (6) and element shell weld together according to the method for claim 7.