WO1996025619A1

WO1996025619A1 - Method and device for sealingly interconnecting a mechanical member and the glass wall of a component

Info

Publication number: WO1996025619A1
Application number: PCT/EP1996/000612
Authority: WO
Inventors: Harald Van Lintel; Ary Saaman; Ad Sprenkels
Original assignee: Westonbridge International Limited
Priority date: 1995-02-14
Filing date: 1996-02-12
Publication date: 1996-08-22
Also published as: JPH10513532A; EP0809770A1; FR2730551A1; AU4875596A

Abstract

A method for sealingly interconnecting a component designed to receive a liquid, particularly a micropump (20), which component has at least one glass wall (10) with an opening for said liquid, and a member (22, 24) also designed to receive the liquid, particularly a tubing (22). The method comprises the steps of providing a connector (30) made of silicon; sealingly attaching one surface of the connector to said glass wall (10); depositing a gold layer (38) on the planar surface of the member around said opening; and heating at least the contact area between said surfaces to a predetermined temperature T to form a eutectic between the silicon and the gold, whereby a seal is achieved between said connector and said member.

Description

Method and device for tight connection between a mechanical member and the glass wall of a component

The present invention relates to a sealed connection method and a sealed connection device between a mechanical member and the glass wall of a component.

More specifically, the present invention relates to a method and a device which makes it possible to ensure a liquid and gas tight connection between a component which has a glass wall provided with an orifice for a liquid and a member also intended for receive this liquid. This problem arises in particular but not exclusively in the case where it is wished to tightly connect a micropump of the piezoelectric control type or a sensor, in particular a pressure sensor, in which the body of the pump or of the sensor is consisting of a glass and silicon sandwich, the body of this sensor or of this pump must be tightly connected to a liquid storage container or to an outlet pipe of the pump.

Even more precisely, there are still a certain number of situations in which it is necessary to form a sealed connection, including a vapor connection, between a member such as a pressure sensor or a micropump and an outlet pipe or a liquid storage tank, this member having a wall of glass or similar material. This is typically the case of micropumps which must be implanted in the human body to deliver a perfectly controlled flow of liquid. We understand that, due to the presence of a glass wall, the realization of a sealed connection is difficult, by conventional techniques, because the mechanical connection involves subjecting the assembly to high temperatures and subsequent cooling. , which can cause mechanical stresses in the parts, these stresses can affect the functioning of the organ and even possibly eventually lead to a rupture of the sealed connection.

An object of the present invention is to provide a method of hermetic connection between an organ comprising a glass wall or analogous and a piece of metal, preferably waterproof and durable over time.

To achieve this goal, the sealed connection method between a component intended to receive a liquid, said component having at least one glass wall provided with an orifice for said liquid, and a member also intended to receive said liquid, said component having an orifice formed in a flat face, is characterized in that it comprises the following stages:

- A connector made of silicon is provided having a first opening opening in a first face and a second opening opening in a second planar face;

- Said connector is fixed in a sealed manner by its first face to said glass wall of said component in such a way that said orifices are opposite; - A layer of gold is deposited on the flat face of said member around said orifice;

- Said face of the member covered with gold is placed opposite said second flat face of the connector with contact so that the orifices coincide; - At least the contact area of said faces is heated to a predetermined temperature T so that a eutectic is created between silicon and gold, whereby a sealed mechanical connection is obtained between said connector and said member.

It is understood that, thanks to the invention, the problem of the connection between the glass wall and the member intended to receive the liquid is solved by the interposition of a silicon connector and the implementation of a connection mechanical by creating an eutectic between silicon and gold. This eutectic corresponds to a relatively low temperature which thus avoids introducing by thermal stress induced forces into the assembly constituted by the two connected parts.

Preferably, said member is made of titanium, this member possibly being for example the wall of a container in which is stored the liquid to be dispensed, for example by a micropump or the outlet pipe of the micropump. Preferably, the silicon connector is fixed to the glass wall of the component by anodic welding. The invention also relates to a sealed connection device between a component intended to receive a liquid, said component having at least one glass wall provided with a hole for the liquid and a member also intended to receive said liquid, said member having a orifice formed in a flat face, which is characterized in that it comprises: a connector made of silicon having a first opening opening in a first face and a second opening opening in a second flat face, said first face of the connector being fixed sealingly on the glass wall so that said orifices are opposite; a layer of gold deposited on the flat face of said member around said orifice, said orifice of said member being disposed opposite the orifice of the second flat face of the connector; and a layer of silicon-gold insectic between said connector and said layer of gold.

Other characteristics and advantages of the present invention will appear better on reading the following description of an embodiment of the invention given by way of non-limiting example. The description refers to the appended figures in which:

- Figure 1 is a simplified perspective view of a micropump;

- Figure 2 is a vertical sectional view of the micropump of Figure 1 to which are respectively connected a pipe and a reservoir by the implementation of the method according to the invention;

- Figure 3 is a top view of a silicon connector used in the implementation of the method; and

- Figure 4 is a vertical sectional view along the plane IV-IV of Figure 3. As already indicated, the invention applies in particular to the sealed connection of the inlet and outlet ports of a micropump with different organs. In Figure 1, there is shown schematically such a micropump which is constituted by a first glass wall 10 in which are respectively provided an inlet orifice and an outlet orifice of the pump, a silicon plate 12 constituting a deformable membrane and two pieces of glass 14 and 16 fixed on the other face of the silicon wafer 12, leaving part of the external face 12a of the silicon membrane free. To avoid the introduction of mechanical stresses in this structure, the connection between the glass 10, 14, 16 and the silicon 12 is preferably carried out by anodic welding. This technique known per se consists in bringing all the silicon and glass parts to a temperature of the order of 300 ° C. and in placing this sandwich between two electrodes in contact with the silicon and glass plates by applying a negative potential of the order of -800 volts at the electrode applied against the glass. There is thus obtained a sealed weld at relatively low temperature between the silicon membrane and the various pieces of glass. The operation of the pump is controlled by a piezoelectric sensor 18 which is fixed to the bare face 12a of the silicon membrane 12. The mechanical stresses induced by the electrical control of the piezoelectric sensor 18 cause deformations of the membrane 12 , which controls the entry and exit of the liquid in the micropump. An example of such a micropump is described in document WO-A-92/01160.

Referring now to FIG. 2, we will describe the implementation of the invention for making a sealed connection between the micropump 20 of FIG. 1 and, on the one hand, an outlet pipe 22 and, on the other hand, a liquid storage tank 24. In this figure, there is shown the outlet orifice 26 and the inlet orifice 28 of the pump which are respectively drilled in the glass plate 10. To make the sealed connection between the outlet orifice 26 formed in the plate 10 and the tubing 22 which is preferably made of titanium, we begin by fixing a silicon connector 30 opposite the orifice 26 on the external face of the glass plate 10 .

Figures 3 and 4 show an embodiment of this connector. It of course has an axial orifice 32 and a first flat face of reduced surface 34 intended to be fixed on the glass plate 10 of the micropump and a second flat face of larger surface 36 intended to be fixed on one end of the pipe 22. The face 34 of the connector 30 is welded to the glass plate 10 by an anode welding technique already described. Before fitting the tubing 22, a flat connection face 22a is produced deposit of reduced thickness gold 38. This deposit can be carried out by any suitable technique, for example by spraying, by electro¬ deposition, by fusion or by a combination of these techniques.

In a second step, the end 22a provided with its gold deposit 38 is placed opposite with the connection face 36 of the connector 30. The temperature is locally raised to a value of the order of 400 ° C. At this temperature, an eutectic is produced between the silicon of which the connector 30 is made and the gold deposit, which ensures a sealed mechanical connection between the end of the pipe 22 and the connector 30. In addition, this connection is obtained at a relatively low temperature, around 400 ^° C, which avoids the introduction of thermal stresses in the assembly formed by the body of the micropump and the tubing 22.

FIG. 2 also shows the sealed connection between the inlet pipe 26 of the micropump 20 and an outlet orifice 40 of the reservoir 24 containing the liquid intended to circulate in the pump. We use the technique already described which consists in fixing a second connector 30 'on the glass plate 10 opposite the orifice 28 to deposit a thin layer of gold 38' on the face of the wall of the tank. around the orifice 40 and then heating the assembly in such a way that, around 400 ° C., a eutectic is obtained between the gold and the silicon. The two members, that is to say the reservoir 24 and the tubing 22, can be made with the same material. Preferably, these parts are metallic, and more preferably made of titanium. A sealed mechanical connection is thus obtained between the reservoir, more precisely its orifice 40, and the connector 30 ′, that is to say between the reservoir 24 and the body of the micropump 20.

Preferably, the connector 30 or 30 ′ has a relatively large surface for its face 36 intended to be fixed on the end piece of the tube 22 or on the tank plate 24. On the other hand, the surface of the end 36 intended to to be fixed on the glass plate is relatively reduced. This arrangement allows a better distribution of thermal stresses, which favors the relaxation of internal mechanical stresses. Part of the stress is absorbed by gold which is a relatively soft metal. The biggest part of the rest of the components is absorbed by the silicon connector, the latter material being very resistant.

In Figure 2, it has been shown that the tubing 22 is fixed by the connector 30 on the micropump. On the other hand, it is important that the tubing 22 is not rigidly integral with the plate 42 forming the reservoir 24. In fact, this would induce stresses at the connectors 30 and 30 'due to the difference in coefficients of thermal expansion between the glass and the material from which the wall 42 is made. To resolve this problem, the tube 22 freely crosses the wall 42 through an orifice 44. The seal between the plate 42 and the tube 22 can be produced with a deposit of a low setting temperature material such as glue 46.

In the example described above, we have considered the case of a micropump. It goes without saying that the method and the device according to the invention can be used for the sealed connection between other components having a glass wall or the like and other members such as pipes, tanks, etc., in which must circulate a liquid.

Claims

1. A method of tight connection between a component (20) intended to receive a liquid, said component having at least one glass wall (10) provided with an orifice for said liquid, and a member (22, 24) also intended to receiving said liquid, said member having an orifice formed in a flat face, characterized in that it comprises the following steps:

- Providing a connector (30, 30 ') made of silicon having a first opening opening in a first face (34) and a second opening opening in a second planar face (36);

- Said connector is fixed in a sealed manner by its first face to said glass wall in such a way that said orifices are opposite;

- A layer of gold (38) is deposited on the flat face of said member around said orifice;

- Said face of the member covered with gold is placed opposite said second flat face of the connector with contact so that the orifices coincide;

- At least the contact area of said faces is heated to a predetermined temperature T so that a eutectic is created between silicon and gold, whereby a tight connection is obtained between said connector and said member.

2. Method according to claim 1, characterized in that said member (22, 24) is made of titanium.

3. Method according to any one of claims 1 and 2, characterized in that said connector (30, 30 ') is fixed to said glass wall of the component by anodic welding.

4. Method according to any one of claims 1 to 3, characterized in that said temperature T is less than 400 ^* C.

5. Method according to any one of claims 1 to 4, characterized in that the surface of the first face (34) of said connector is reduced relative to that of its second face (36).

6. Method according to any one of claims 1 to 5, characterized in that said component (20) is a micropump and said member is a tube (22) and / or a reservoir (24).

7. A sealed connection device between a component (20) intended to receive a liquid, said component having at least one glass wall (10) provided with an orifice for the liquid and a member (22, 24) also intended to receive said liquid, said member having an orifice formed in a flat face, characterized in that it comprises: a connector (30, 30 ') made of silicon having a first opening opening in a first face (34) and a second opening opening in a second planar face (36), said first face of the connector being tightly fixed on the glass wall so that said orifices are facing one another; a layer of gold (38) deposited on the planar face of said member around said orifice, said orifice of said member being disposed opposite the orifice of the second planar face of the connector; and a layer of silicon-gold insectic between said connector and said layer of gold.

8. Connection device according to claim 7, characterized in that said member is made of titanium.

9. Connection device according to any one of claims 7 and 8, characterized in that the surface of the first face (34) of said connector is reduced relative to that of its second face (36).

10. Connection device according to any one of claims 7 to 9, characterized in that said component (20) is a micropump and said member is a tube (22) and / or a reservoir (24).