JPS61191962A - Column for chromatography and manufacture thereof - Google Patents

Abstract

PURPOSE:To achieve a small size and a higher mechanical strength of a column, by providing an Si base body to make a column. CONSTITUTION:A spiral groove 11 is formed on the surface of a first Si base body 10 and an introduction hole 12 and a discharge hole 13 are formed at the initial and final ends of the groove 11 piercing the Si base body 10. First and second Si bodies 10 and 20 are joined together directly using no adhesive. Thus, a smaller size and a higher mechanical strength can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a chromatography column, and particularly to a chromatography column excellent for high performance liquid chromatography and a method for manufacturing the same.

[Technical background of the invention and its problems]

High-performance liquid chromatography is attracting attention as a technique for separating liquid components (Reference: High-performance liquid chromatography analysis 9, Kanto branch of the Japanese Society for Analytical Chemistry, 1i, 1983).
. This involves filling a thin tube called a column with an adsorbent.
This is a method in which the sample to be separated is passed under high pressure together with a liquid such as alcohol, and the sample is adsorbed and separated.

Conventionally, stainless steel tubes with an inner diameter of 20 [', am] and a length of about 30 [1 tube] have been used as columns for high performance liquid chromatography, but due to demands for ease of work and miniaturization of equipment, columns The miniaturization of the is being considered. For example, there is a method using a fluororesin tube 9 quartz glass capillary with an inner diameter of about 0.5 [a*]. Miniaturization has advantages such as reducing the amount of waste solvent after using the liquid medium and making on-site analysis possible, but this type of method has problems such as weak mechanical strength and protection. There was a limit to the miniaturization of the column itself due to the need for a column.

On the other hand, as a column for gas chromatography, there is one in which a spiral groove is formed on the surface of a Si substrate, and a glass plate is bonded to the surface of the Si substrate via an adhesive so as to cover the groove. However, in this structure, Si
The bonding strength between the substrate and the glass plate is not sufficient, so it cannot be used as is as a column for high performance liquid chromatography. That is, in the case of gas, the number [Ky / at
] is sufficient, but in the case of liquids, it is necessary to withstand pressures of several tens to hundreds of [Ng/cj], and methods using adhesives cannot withstand this pressure. be. Furthermore, since an adhesive is used, there is a risk that a reaction between the liquid flowing into the groove and the adhesive will occur (the adhesive will melt), resulting in poor reliability.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances, and its purpose is to be excellent for high-speed chromatography,
Our objective is to provide a small and highly reliable chromatography column.

Another object of the present invention is to provide a method for manufacturing a chromatography column having the above structure.

[Summary of the Invention] The gist of the present invention is to directly bond a first Si substrate in which a groove is formed and a second Si substrate, which acts as a “lid” to close the groove, without using an adhesive. The objective is to form a column using

As mentioned above, in the case of liquid chromatography, for example, the number
Because a high pressure of ~100 [Nf/cIi] is applied,
The joint requires strong adhesion that can withstand this pressure. Direct bonding of Si substrates can sufficiently withstand this pressure.

Direct bonding of Si substrates may be performed as follows. For example, the surface is polished to a surface roughness of 5001' or less by mirror polishing or the like to make the surface hydrophilic. The hydrophilic state is confirmed by the fact that when a drop of water is placed on the surface, it does not repel water but spreads thinly. Examples of the treatment method for making it hydrophilic include washing with water and exposing it to the air. Normally, a strictly controlled Si substrate surface is water repellent, but this treatment changes it to hydrophilicity. Such hydrophilicity is thought to be due to the formation of a natural oxide film. Formation of a natural oxide film is also possible using techniques such as heating in air.

Strong adhesion can be obtained by bringing hydrophilic Si substrates into close contact with each other in a clean atmosphere free from foreign matter such as dust, and heating to 200[° C.] or higher. This bond does not leak even under high pressure conditions such as in liquid chromatography, and is highly reliable. Needless to say, it can also be used for gas chromatography. Since the Si substrates are bonded to each other, there is no warpage after bonding, and since the grooves are embedded in the Si substrate, the mechanical strength is sufficient.

Grooves can be formed on the Si substrate by using an ordinary etching method, and by thoroughly washing with water after removing the resist, the above-mentioned hydrophilic surface can be obtained. Although the shape of the groove may be any shape as long as it is continuous, it is preferable to form it in a spiral shape because the flow of the liquid sample is less likely to be obstructed. If it is desired that the inner surface of the column be covered with SiO2, the grooved wafer to be bonded and the wafer serving as the lid are treated in an oxidation furnace or the like in advance, and the entire surface including the groove inner surface is coated with SiO2. After attaching 02 jl, it is sufficient to perform the joining. Further, by providing a diffusion resistance layer on the surface of the Si substrate on the lid side, it is possible to provide a function to keep the temperature of the column constant.

Although the bonding mechanism between Si substrates is not clear, active silanol groups (S
It is thought that dehydration condensation by heating of i-OH) provides a strong bond.

The present invention has been made with attention to such points, and therefore, in a chromatography column, a first 8i substrate having continuous grooves formed on the surface, and a first 8i substrate having a first 8i substrate formed with continuous grooves on the surface thereof, and the above-mentioned 8i substrate having continuous holes formed by sealing the grooves. a second Si substrate directly bonded to the first 8i substrate; an introduction hole provided in the first or second Si substrate so as to communicate with the hole for introducing the sample to be measured into the hole; said first or second so as to communicate with
The S11 substrate is provided with a discharge hole through which the sample to be measured is discharged from the hole.

Furthermore, in addition to the above structure, the surface of the second Si substrate is selectively doped with impurities to provide a diffused resistance layer.

The present invention also provides a method for manufacturing a chromatography column having the above configuration, in which each surface of the first and second 8i substrates is polished to form continuous grooves on the surface of the first Si substrate; Further, an introduction hole for introducing the sample to be measured into the groove and a discharge hole for discharging the sample are provided in the first or second Si substrate, and then a predetermined hole is provided in the first or second Si substrate. The surfaces of these substrates are made hydrophilic by treatment, and then the first and second substrates are treated in a clean atmosphere.
The surface of the Si substrate of 200 ["0
In this method, each of the substrates is bonded to each other by heating to a temperature of 1 or more.

Furthermore, in addition to the above method, this method includes forming a diffused resistance layer by doping with impurities.

〔Effect of the invention〕

According to the present invention, the direct bonding of the Si substrates is extremely strong compared to conventional bonding methods, so that it can sufficiently withstand high pressures of about 100 [#/cm 2 ].

Here, the reason why it can withstand high pressure is that Si substrates are similar or S
This is due to the direct bonding of wafers with iO2 coatings. With conventional electrostatic adhesion methods, it is not possible to sufficiently increase the moisture content during bonding due to the movement of Na ions, etc.
It was virtually impossible to obtain a column that could withstand a pressure of [g/cIII]. Furthermore, since there is no need to use an adhesive, there is no risk of a reaction between the adhesive and the sample to be measured or a liquid such as alcohol. Therefore, it is possible to increase the speed, and it is possible to construct an ultra-small and high-speed chromatography system.

[Embodiments of the invention]

Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

1 and 2 are for explaining the schematic structure of a liquid chromatography column according to an embodiment of the present invention, respectively, with FIG. 1 being a plan view and FIG. 2 being a sectional view.

A spiral groove 11 is formed on the surface of the first Si substrate 10, and an introduction hole 12 and a discharge hole 1 for the sample to be measured that pass through the Si substrate 10 are formed at the starting and ending ends of the groove 11.
3 are formed respectively. The first and second Si substrates 10.20 are then directly joined without using an adhesive.

FIGS. 3(a) to 3(h) are cross-sectional views showing the manufacturing process of the above example column.

First, a first Si with a diameter of 3 inches and a thickness of 450 [μm] is prepared.
After mirror polishing the surface of the base 10 to a surface roughness of 500 [mm] or less, as shown in FIG.
000 [person] SiO2 film 31 film type 1 was made. Next, as shown in FIG. 3(b), holes were drilled using a laser using the resist pattern 32 formed on the back side of the Si substrate 10 as a guide to form the introduction hole 12 and the discharge hole 13.

Next, as shown in FIG. 3C, a resist pattern 33 for forming grooves was formed on the surface side of the Si 1 body 10 using the holes 12 and 13 as marks. This resist pattern 33 had a spiral shape with a groove width of 100 [μm] and a pitch between grooves of 250 [μTrL1, and the number of turns was 95. The drawing was performed using Archimedes' equation. Next, as shown in FIG. 3(d), using the resist pattern 33, the surface side pS10 is etched with an etching solution of HF+N84F.
The second layer 31 was etched to create a SiO2 mask 31a. Next, as shown in FIG. 3(e), the Si substrate 10 is etched (HNO3) using the SiO2 mask 31a.
+) IF +CH3C00H) to form spiral grooves 11. Thereafter, HF+N84F etching was performed to form the SiO2 film 31 into a film shape 1 as shown in FIG. 3(f).

The thus obtained first Si substrate 10 was sufficiently washed with water to make it hydrophilic, and then dried using a spinner.

On the other hand, as shown in FIG. 3i), the second Si substrate 20 is
After washing with water in the same manner as the Si substrate 10, it was dried using a spinner. Next, in a clean atmosphere of class 1000 or less, the first Si substrate 10 is heated as shown in FIG. 3(h).
The first and second Si substrates 10.20 are brought into close contact with each other so that the second Si substrate 20 closes the groove 11 of the substrate 115.
Heating was performed at 0 [° C.] for 2 hours to bond each substrate 10.20.

A pressure test was conducted using the column thus obtained. For the test, the groove width was 100 [μm].

Depth 20 [μm], hole diameter 1 of introduction hole 12 and discharge hole 13
After filling the column with water as a pressurized test liquid using a bonded body of wafers processed to a diameter of 0.00 [μm], the discharge hole 1
3 was closed and pressurized through the introduction hole 12 with a pump. As a result, the wafers sufficiently withstood 120 [K9/cat], and although some wafers cracked when this pressure was exceeded, no peeling of the bonded portion was observed.

Next, a column was prepared in which 1000 SiOz films were formed on the inside of the groove and on the surface of the lid part by steam oxidation before bonding, and then wafers were bonded, and the wafers were cleaned before bonding. When this column was also measured in the same manner as above, it was found that 120 [
It was confirmed that it could sufficiently withstand a pressure of /(g/cd).

From the above results, the pressure resistance is higher than that of conventional columns, so in addition to being compact, the volumetric velocity can be sufficiently increased even if the length of the column is increased. This means that more than 10 times more columns have been created.

As described above, according to this embodiment, by providing grooves in the S (substrate 10) and using the grooves as columns, it is possible to reduce the size of the column and improve the mechanical strength.

Furthermore, the first and second Si substrates 10 and 20 are directly bonded without using an adhesive, resulting in strong bonding.

can be formed. For this reason, it is extremely effective in realizing high-performance liquid chromatography and can be miniaturized. Further, since no adhesive is used, there is no problem such as reaction between the liquid flowing in the groove and the adhesive, and the reliability is high.

FIGS. 4(a) to 4(C) are cross-sectional views showing a column manufacturing process according to another embodiment of the present invention.

This embodiment differs from the previously described embodiments in that a diffusion resistance layer is provided on the surface of the first Si substrate 10, and
This is because an insulating film is provided on the surfaces of the first and second substrates 10.20.

That is, after the step shown in FIG. 3(f), the first Si substrate 10 is coated with a SiO2 film 41 on its surface, inside the grooves, and inside the holes by steam oxidation, etc., as shown in FIG. 4(a). coated. On the other hand, the surface of the second Si substrate (P-type wafer) 20 was selectively doped with N-type impurities to form an N-type diffused resistance layer 42, as shown in FIG. 4(b). Here, the pattern of the resistive layer 42 is formed on the base 20 as shown in FIG.
It was designed as a single curved line that could cover the entire surface of the area. Next, the surface of the second Si substrate 20 was also coated with a SiO2 film 43 by steam oxidation or the like.

Next, as shown in FIG. 4(C), the first and second Si substrates 10.20 were brought into close contact with each other in a clean atmosphere in the same manner as before, and the substrates 10.20 were bonded by heat treatment. after that,
A part of the SiO2 film 43 was removed to form a contact hole for supplying electricity to the resistance layer 42. Note that the first S
i By providing a notch in a part of the base 10,
As shown in FIG. 6, the electrode connection portion 45 of the diffused resistance layer 42
can be left exposed even after bonding.

In the thus formed column, the bonding strength between the first and second Si substrates 10.20 is sufficiently high, and therefore the same effects as in the first embodiment can be obtained. In addition, since the diffusion resistance layer 42 is provided, there is no need to use a constant temperature bath.
The temperature of the entire column can be made uniform. Therefore, there is an advantage that the system can be simplified. Further, when electrostatic deposition is used, the heater resistance fluctuates due to the diffusion of Na ions, but this embodiment does not have such inconvenience.

Note that the present invention is not limited to each of the embodiments described above. For example, the diffusion resistance layer is not limited to a series of heaters, but may be formed separately on the surface of the second Si substrate as shown in FIG. In this case, since each resistance layer can be controlled independently, it becomes possible to more effectively equalize the temperature of the column. That is, the column is formed approximately point-symmetrically from the center of the wafer, but in practice it is necessary to suspend the blade ram, and heat flows out from this suspension portion, lowering the temperature in the vicinity. Therefore, in the method of separating the resistance layers, it is possible to equalize the overall temperature by increasing the heater power of the suspension section. Furthermore, by forming the first Si substrate to have a smaller diameter than the second substrate 3, the electrode connection portion of the resistance layer can be provided on the outer periphery of the column as shown in FIG. moreover,
It is not necessary to provide a notch in the first Si substrate or to provide the first Si substrate with a diameter smaller than that of the second Si substrate in order to connect the electrodes of the resistance layer. A contact hole may be provided that reaches the layer.

Further, the heating temperature when joining the first and second Si substrates is not limited to 1150 [°C], but may be 200°C.
[°C] or higher, preferably 1000 [°C] or higher. Furthermore, the surface polishing state of the first and second Si substrates may be as long as the surface roughness is 500 [people] or less. Also,
Of course, it can be used not only for liquid chromatography columns but also for gas chromatography columns.

In addition, various modifications can be made without departing from the gist of the present invention.

[Brief explanation of the drawing]

Figures 1 and 2 are for explaining the schematic structure of a liquid chromatography column according to an embodiment of the present invention, respectively. Figure 1 is a plan view, Figure 2 is a sectional view, and Figure 3 ( a) to (h) are cross-sectional views showing the manufacturing process of the above-mentioned Example column, FIGS. 4(a) to (C) are cross-sectional views showing the manufacturing process of a chromatography column according to another example, and FIG. 6 is a plan view showing a resistive layer pattern, FIG. 6 is a plan view showing an electrode connection portion, and FIG. 7 is a plan view for explaining a modification. DESCRIPTION OF SYMBOLS 10... First Si substrate, 11... Spiral groove, 12... Introduction hole, 13... Discharge hole, 2o... Second Si substrate, 31, 41.43... SiO2 film, 3
2.33... Resist pattern, 42... Diffused resistance layer, 45... Electrode connection portion. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 4 Figure 5 b Figure 6

Claims (23)

[Claims] (1) a first Si substrate having a continuous groove formed on its surface; a second Si substrate directly bonded to the first Si substrate so as to seal the groove and form a continuous hole; an introduction hole provided in the first or second Si substrate so as to communicate with the hole and for introducing the sample to be measured into the hole; A chromatography column characterized in that it is equipped with a discharge hole through which a sample to be measured is discharged. (2) The chromatography column according to claim 1, wherein the groove is formed in a spiral shape. (3) The chromatography column according to claim 2, wherein the introduction hole and the discharge hole are formed at a starting end and a terminal end of a spiral groove. (4) The chromatography column according to claim 1, wherein the surface of the first Si substrate is coated with a SiO_2 film. (5) a first Si substrate having a continuous groove formed on its surface; a second Si substrate directly bonded to the first Si substrate so as to seal the groove and form a continuous hole; an introduction hole provided in the first or second Si substrate so as to communicate with the hole and for introducing the sample to be measured into the hole; a discharge hole for discharging the sample to be measured from the hole; and the second Si
A column for chromatography, comprising: a resistance layer formed by selectively doping impurities on the surface of a substrate; and an insulating film coated on the surface of the second Si substrate. (6) The chromatography column according to claim 5, wherein the groove is formed in a spiral shape. (7) The chromatography column according to claim 6, wherein the introduction hole and the discharge hole are formed at a starting end and a terminal end of a spiral groove. (8) The chromatography column according to claim 5, wherein the surface of the first Si substrate is coated with a SiO_2 film. (9) The chromatography column according to claim 5, wherein the resistance layer is divided into a plurality of pieces on the surface of the second Si substrate. (10) A patent characterized in that a cutout is provided in a portion of the first Si substrate to partially expose the surface of the second Si substrate, and an electrode connection portion of the resistive layer is provided in this portion. The chromatography column according to claim 5. (11) A patent claim characterized in that the first Si substrate has a diameter smaller than that of the second Si substrate, and the electrode connection portion of the resistive layer is provided on a surface exposed portion of the second Si substrate. The chromatography column according to item 5 or 9. (12) mirror polishing each surface of the first and second Si substrates; forming continuous grooves on the surfaces of the first Si substrate; A step of providing an introduction hole for introducing a sample to be measured into the groove and a discharge hole for discharging the sample, then a step of making each surface of the first and second Si substrates hydrophilic, and then a cleaning step. A chromatography column characterized by comprising the step of: bringing the surfaces of the first and second Si substrates into close contact with each other in a suitable atmosphere, and heating the substrates in this state to a temperature of 200[° C.] or higher to bond the respective substrates together. manufacturing method. (13) The method for manufacturing a chromatography column according to claim 12, wherein the groove is formed in a spiral shape. (14) The method for manufacturing a chromatography column according to claim 13, characterized in that the introduction hole and the discharge hole are formed at a starting end and a terminal end of a spiral groove. (15) The method for manufacturing a chromatography column according to claim 12, wherein the surface of the first Si substrate is coated with a SiO_2 film. (16) The method for producing a chromatography column according to claim 12, wherein the step of making each substrate hydrophilic includes washing each substrate with water or exposing it to clean air. (17) As the polishing step, the surface roughness is 500 [Å
] The method for manufacturing a chromatography column according to claim 12, characterized in that the column is mirror-polished. (18) mirror-polishing each surface of the first and second Si substrates; forming continuous grooves on the surfaces of the first Si substrate; a step of providing an introduction hole for introducing the sample to be measured into the groove and a discharge hole for discharging the sample; and forming a diffused resistance layer by selectively doping impurities on the surface of the second Si substrate. a step of coating the surface of the second Si substrate with an insulating film, a step of making each surface of the first and second Si substrates hydrophilic, and then a step of coating the surface of the first Si substrate in a clean atmosphere. and a step of bonding the surfaces of a second Si substrate to each other by heating the surfaces of the second Si substrate to 200 [° C.] or higher to bond the substrates together. (19) The method for manufacturing a chromatography column according to claim 18, wherein the groove is formed in a spiral shape. (20) The method for manufacturing a chromatography column according to claim 19, wherein the introduction hole and the discharge hole are formed at a starting end and a terminal end of a spiral groove. (21) The method for manufacturing a chromatography column according to claim 18, wherein the surface of the first Si substrate is coated with a SiO_2 film. (22) The method for producing a chromatography column according to claim 18, wherein in the step of making the substrate hydrophilic, each of the substrates is washed with water or exposed to clean air. (23) As the polishing step, the surface roughness is 500 [Å
] The method for manufacturing a chromatography column according to claim 18, which comprises mirror polishing.