CZ305166B6 - Deposition method of chip microelectrodes distributed on a board using chemical solutions and apparatus for making the same - Google Patents

Abstract

The deposition method of chip microelectrodes distributed on a board using chemical solutions according to the present invention is characterized in that a board is fastened onto a table of a positioning device provided with an application nozzle, which is situated above the selected electrode of the first chip, and pressed to the board. Subsequently, deposition solution, acting on the selected electrode, is supplied into the nozzle, and continuously withdrawn therefrom. After stopping the flow of the deposition solution into the nozzle and sucking off the residual solution, the nozzle is lifted and transferred above the next electrode of the adjacent chip, and the above-described process is repeated. Apparatus for making the above-indicated method consists of a positioning device (1) with accuracy of localization in the order of microns. A chipboard (4) clamping device is arranged on the positioning device (1). A nozzle (3) directing to the chipboard (4) is fastened on the positioning device (1) arm (2) sliding in the x, y and z-axes. A deposition solution jet (5) is fastened in the nozzle (3) axis, while the deposition solution circuit is performed in the wall thereof. The nozzle (3) is connected via a pump (8) to at least one deposition solution storage tank (7). In preferred embodiment, the apparatus is provided with a thermostat (6). A programmable control unit (11) is connected with drives of the positioning unit (1), a pump (8), a solution change-over switch (9), an electrode (10), and the thermostat (6).

Description

Technical field

The invention relates to a method for deposition of microelectrodes of chips placed on a board by means of chemical solutions, in particular electrode deposition of electrochemical microsensors. It further relates to an apparatus for carrying out this method.

BACKGROUND OF THE INVENTION

Electrochemical microsensors consist of microelectrodes which are the main part of these sensors and electrochemical sensor systems. The disadvantages of the sensors are very low response, insufficient sensitivity and especially poor detection limit. Microsensors are produced using thin-film and semiconductor technology, possibly supplemented with micro-machining processes. Semiconductor technology is mainly used to create electronics for signal processing from sensors. The procedures are identical or at least compatible with the manufacture of integrated circuits. Typically, ICs and microsystems are manufactured and shipped on silicon wafer or other materials, mostly dielectric, such as Pyrex or Symax. Chips, whether semiconductor or semiconductor-free, contain microelectrodes which, after all processes, whether semiconductor processes, or thin-film technologies, or micro-machining, are bare, unsaturated, unlike the rest of the system, which is thus protected from environmental influences. However, semiconductor technology does not make it possible to create special layers on metallic microelectrodes and modify them with nanostructures from different materials.

US 6,824,666 and US 2007/111519 disclose methods for depositing various materials on the surface of a backing layer by means other than electrochemical methods. Layers of thickness of the order of microns are formed on the board with the properties of conductors, semiconductors, insulators and cover layers. Coating is performed mainly by steaming or by the action of liquids. Wet and mechanical cleaning are also part of the manufacturing operations. The individual operations are carried out on the entire surface of the backing layer in single-operation chambers, deployed on a platform equipped with manipulators, which transfer products from one workstation to another. Manipulators consist of swivel, extendable and tilting arms.

Said deposition methods are intended for the production of semiconductor boards as a whole, they do not allow point interventions into their already finished structure.

Techniques have been developed to create nanopores, nanowires, nanotubes and nanotubes, which can be used to transform the surface of the metal layers that make up the electrodes. So far, these techniques are rarely used in laboratory conditions on individual chips broken off the board. However, modification of the electrodes, however desirable, is generally not due to the difficulties mentioned. At the same time, modification of the sensor electrodes is highly desirable because it improves the conversion properties of the measured variable, usually improving sensitivity, response size and detection limit.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for modifying the electrodes at a substantially larger scale and at a lower cost, while also providing an apparatus for carrying out the method.

SUMMARY OF THE INVENTION

This object solves the method of deposition of microelectrodes of chips placed on the board by means of deposition solutions supplied to and removed from the board, which consists in that the board is fixed on the table of the positioning device equipped with the application nozzle, which is inserted above the selected

The electrode of the first chip is pressed against the plate, then a deposition solution is applied to the nozzle, which acts on the selected electrode, and is continuously withdrawn from the nozzle, after which the nozzle is lifted after the deposition of the deposition solution has stopped. and replaces the next electrode of the adjacent chip and repeats the procedure.

In practical application, the electrode is treated successively with several deposition solutions.

Preferably, a controlled electrical voltage can be applied to the nozzle and plate.

It is also advantageous to control the temperature of the feed chemical solution and / or the temperature of the chip board during the deposition process.

The position of the nozzle, the selection of the solution, its temperature, the inlet and outlet as well as the temperature of the plate and the value of the voltage or current passing through the electrode are preferably controlled by a programmable control unit.

The apparatus for carrying out the above-described method consists of a positioning device with a localization accuracy of the order of pm, on the table of which the chip plate clamp is located and on its arm movable in x, y and z axes. its discharge, wherein the nozzle is connected via a pump to at least one deposition solution reservoir.

In a preferred embodiment, the device is provided with several deposition solution reservoirs with a solution switch.

The device may be provided with a contact electrode on the table.

Preferably, the device is provided with a thermostat to control the temperature of the deposition solutions and the plate.

In a very preferred embodiment, the actuators of the pointing device, the pump and the solution switch, the electrode and the thermostat are connected to a programmable control unit.

Clarification of drawings

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further elucidated by means of a drawing, in which an exemplary embodiment of an electrode deposition apparatus for electrochemical microsensors is schematically illustrated.

DETAILED DESCRIPTION OF THE INVENTION

Deposition of microelectrodes of the chips takes place by attaching a plate on a table of a positioning device equipped with an application nozzle, on which the chips are placed by the manufacturer in a regular grid. The nozzle is inserted over the selected electrode of the first chip, lightly pressed against the plate, then a deposition solution is applied to the nozzle, which acts on the selected electrode. The solution is continuously removed from the nozzle. After the deposition solution has been stopped, the residual solution is aspirated from the nozzle, the nozzle is lifted and moved over another electrode of the adjacent chip and the process is repeated. In practical application, the electrode is treated successively with several deposition solutions and a controlled electrical voltage or current is applied to the die and plate. Also, during the deposition process, the temperature of the supplied deposition solution and also the temperature of the chip board are controlled.

A schematic sketch of the deposition device is shown in Fig. 1. It is based on a positioning device with three movable slides, whose sliding movement is controlled by servomotors. All three slides, the last of which has an arm 2, move the deposition nozzle 3 in three x, y, z axes. In the z-axis, the deposition nozzle 3 is lowered onto the plate 4 with the py-2 exactly at the location designated by the x and y axes. The range of the x and y axes must be such that they cover the entire board of 4 chips. In the described apparatus, the range is 100 x 100 mm, which corresponds to 4 plates. The movement accuracy in each direction is 1 pm. This coordinate system makes it possible to adjust the deposition nozzle 3 to the desired microelectrode, which is part of the chips, and to automate the deposition of complex structures by chemical and / or electrochemical methods. After the process is complete, the device can then move to the next chip and continue until all the chips on the board 4 have been modified.

The pressure of the nozzle 3 on the plate 4 is sensed by a force sensor that is connected to the nozzle 3 and ensures that the solution does not leak freely on the plate 4 and at the same time the plate 4 is not damaged. The deposition nozzle 3 itself is flow-through, with the solution entering through a metal nozzle 5, which also serves as an electrode and exits through the side opening of the nozzle 3. The solution can be tempered by a thermostat 6, for example by circulating liquid, to the desired temperature. The supply of the solution from the reservoirs 7 is provided by a diaphragm, peristaltic or linear pump 8, which must be equipped with the possibility of flow control ranging from μ od to tens of ml. Changeover of solutions from different containers 7 is provided by the switch 9. The thermostat 6 also controls the temperature of the circulating liquid, which cools or heats the plate, in the range of 0 to 90 °.

The voltage is applied to the plate 4 by a contact electrode 10. The galvanic or anodic deposition source must be capable of operating in current or voltage mode. The voltage range is controllable from tens of mV to tens of volts. The current is adjustable from 100 μΑ to tens of mA.

All actuators of the positioning device 11, as well as all additional devices, are controllable from the programmable control unit 11 so that one process after another can proceed without operator intervention. In addition, a computer is connected to the computer, which together with the horoscope serves to precisely set the starting points of the coordinate system.

In addition, the device can be used for local chemical or galvanic plating of metal layers of any chips, anodic layers and etching, functionalization of layers by various chemical groups or biomolecules. Modifications are carried out by means of solutions, so it is a closed system that is not affected by environmental contaminants. The advantage of the device is that each chip can be modified by a different process and material.

PATENT CLAIMS

Claims (10)

A method for depositing microelectrodes of chips placed on a board by means of chemical solutions supplied to and removed from the board, characterized in that the board is fixed to a table of a positioning device equipped with an application nozzle, which is inserted above the selected electrode of the first chip The deposition solution, which acts on the selected electrode, is then fed to the nozzle and continuously removed from the nozzle. After stopping the deposition of the deposition solution into the nozzle and aspirating the residual solution, the nozzle is lifted and moved over another electrode of the adjacent chip. Method according to claim 1, characterized in that the electrode is treated successively with several deposition solutions. -3 CZ 305166 B6 Method according to claim 1 or 2, characterized in that a controlled voltage or current is applied to the nozzle and the plate. Method according to one of claims 1 to 3, characterized in that the temperature of the chemical solution supplied and / or the temperature of the chip board is regulated during the deposition process. Method according to one of Claims 1 to 4, characterized in that the position of the nozzle, the selection of the solution, its temperature, the inlet and outlet as well as the temperature of the plate and the voltage or current passing through the electrode are controlled by a programmable control unit. Device for carrying out the method according to claim 1 or 2, characterized in that it comprises a positioning device (1) with a positioning accuracy of the order of pm, in which the chip plate clamp (4) is located and on its arm (2) movable axes x, y and z are attached to the nozzle (3) facing the plate (4), in the axis of the nozzle (3) there is a supply nozzle (5) of the deposition solution and its outlet in the wall, the nozzle (3) connected to at least one deposition solution reservoir (7). Device according to claim 6, characterized in that it is provided with a plurality of deposition solution reservoirs (7) with a solution switch (8). Device according to claim 6 or 7, characterized in that it has a contact electrode (10) on the table or on the underside of the nozzle. Device according to one of Claims 6 to 8, characterized in that it is provided with a thermostat (6) for monitoring the temperature of the deposition solutions and the plate (4). Device according to one of Claims 6 to 9, characterized in that the actuators of the positioning device (1), the pump (8) and the solution switch (9), the electrode (10) and the thermostat (6) are connected to a programmable control unit (1). 11).