CN108405005B

CN108405005B - A filling barrier for preventing clogging of nanochannel bonding seals

Info

Publication number: CN108405005B
Application number: CN201810541537.7A
Authority: CN
Inventors: 金建; 邸思; 袁海
Original assignee: Shenzhen Institute of Advanced Technology of CAS; Guangzhou Institute of Advanced Technology of CAS
Current assignee: Shenzhen Institute of Advanced Technology of CAS; Guangzhou Institute of Advanced Technology of CAS
Priority date: 2018-05-30
Filing date: 2018-05-30
Publication date: 2024-08-13
Anticipated expiration: 2038-05-30
Also published as: CN108405005A

Abstract

The invention discloses a filling barrier for preventing nano channel bonding sealing blockage; the filling barrier is a groove structure embedded into a substrate and used for dividing filling quantity, and is positioned at the center of an expansion center line generated when a bonding adhesive layer fills the groove structure; by introducing the filling barrier structure, the displacement generated by pressure in the bonding process is reduced, and the filling quantity is split, so that the top filling is inhibited, and the occurrence of blockage in the process of manufacturing the channel is reduced.

Description

Filling barrier for preventing nano channel bonding sealing blockage

Technical Field

The invention relates to the technical field of micro-nano processing, in particular to a filling barrier for preventing nano channel bonding sealing blockage.

Background

The micro-nano fluid system is an extension and popularization of micro-nano manufacturing technology in the field of biochemistry; micro-nano fluidic systems miniaturize the basic operations of sample preparation, biochemical reactions, separations, detection, etc., involved in biological and chemical fields, etc., onto a planar substrate of a size of a few centimeters or tens of centimeters. By designing a suitable micro-nano channel structure, fluid can flow in the channel in a certain way, so that the chip as a whole can obtain a specific function.

In the fabrication of micro-nano fluidic systems, the top sealing of the micro-channels may be achieved by thermal bonding techniques. However, the polymer in the molten state inevitably flows into the inside of the channel trench structure during bonding. As the size of the fabricated channels decreases, particularly when the size reaches the nanometer level, the conventional bonding method is very prone to channel blockage, which adversely affects the control of the channel size and the process reliability. Therefore, the existing bonding sealing mode is mainly used for manufacturing the micro-scale and above size channels.

The core of the micro-nano fluid system is the processing of the micro-nano fluid channel; thermal bonding is a key technology of sealing a polymer micro-nano channel, and a general micro-nano flow control channel thermal bonding process is shown in fig. 1; firstly, placing a prefabricated groove structure on a lower supporting table, then uniformly and flatly placing an upper substrate with a bonding adhesive layer on the groove, heating the upper platform through heat conduction, heating the bonding layer to the vicinity of or above the glass transition temperature, and achieving entanglement of molecular chains at an interface through infiltration and adhesion, so that tight interface contact is obtained.

In the bonding process, in order to prevent the polymer and the bearing substrate from being influenced by warping caused by different thermal expansion coefficients in the bonding process and keep the bonding adhesive layer and the groove structure in good contact, certain external pressure needs to be applied; the bonding adhesive layer is inevitably extruded, the polymer generates corresponding shear stress in the bonding adhesive layer under the action of pressure, so that the polymer expands from the center to the periphery, and meanwhile, in the Y-axis direction, the flow of the polymer is limited due to the existence of a workbench, so that the polymer can only form extrusion flow downwards along the side wall of the channel under the action of the stress; thereby accelerating the top filling of the polymer and if not well controlled, the clogging of the channels may be caused by this part of the deformation.

X Wang et al in the paper proposed a method of reducing the problem of clogging (journal paper (titled Laser lithographic fabrication and characterization of A SPHERICAL ARTIFICIAL combined eye journal: microelectronic Engineering,2011, 88 (8): 2427-2430), which uses a double bond ply, wherein a thick bond ply is used for the support structure and a thin bond ply is used for the channel seal, and the thin bond ply is thinner, thus reducing the occurrence of channel clogging during bonding.

Disclosure of Invention

The invention provides a filling barrier for preventing nano channel bonding sealing from blocking, which aims at the prior problem, so as to reduce the displacement generated by pressure in the bonding process, split the filling quantity, inhibit top filling and reduce the blocking during channel manufacturing.

In order to achieve the above-mentioned object, the present invention provides a filling barrier for preventing the bonding and sealing blockage of nano-channels, wherein the filling barrier is a groove structure embedded in a substrate for dividing filling quantity and is positioned at the center of an expansion center line generated when a bonding adhesive layer fills the groove structure.

Preferably, the expansion center line is: and a line segment perpendicular to the expansion direction of the bonding adhesive layer and passing through the center point of the height of the expansion direction.

In the embodiment of the invention, a filling barrier structure is designed according to the assumption of an expansion center line so as to reduce the displacement generated by pressure in the bonding process and split the filling quantity, thereby inhibiting top filling and reducing the occurrence of blockage during channel manufacture;

Preferably, when the trench structure is a plurality of rectangular trenches parallel to each other, an expansion center line is generated, the filling barrier also adopts parallel rectangular trenches, and the filling barrier width is larger than the trench structure width.

Preferably, when the trench structure is a complex structure, i.e. when a plurality of expansion centerlines of different directions are generated, the filling barriers are arranged at the center positions of all the trench structures.

Preferably, the filling barrier adopts a circular groove structure.

The groove structure is a micro-nano channel.

In order to reduce the occurrence of channel blockage when sealing a channel, a method is adopted at present, namely, the thickness of a bonding adhesive layer is reduced; secondly, reducing bonding pressure; both of these methods, however, reduce bond strength to some extent and are poorly controlled; the filling obstruction device for preventing the nano channel bonding sealing obstruction provided by the invention has the advantages that the filling obstruction device structure is introduced to realize the flow division effect on the bonding adhesive layer, so that the occurrence of obstruction is reduced, and the realization mode is simpler and easier to operate.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a bonding process;

FIG. 2 is a schematic view of the expansion centerline of the present invention;

FIG. 3 is a schematic illustration of the filling of the present invention;

FIG. 4 is a schematic illustration of the filling situation with auxiliary structure according to the present invention;

FIG. 5 is a schematic view of a first preferred embodiment of the filling barrier according to the present invention;

FIG. 6 is a schematic view of a filling barrier with an outer ring having a circular micro-nano structure according to a second preferred embodiment of the present invention;

FIG. 7 is a schematic view of a micro-nano structured packing baffle with an outer ring having a radial shape according to a third preferred embodiment of the present invention;

FIG. 8 is a graph of deformation magnitudes at various locations from the center of the expansion centerline of the present invention;

Symbol description:

1-a workpiece stage; 2-a substrate; 3-bonding adhesive layer; 4-micro-nano channels; 5-a lower workpiece stage; 6-filling the barrier; l (1) -expansion centerline; (2) -a fill position; (3) -an expansion centerline center position;

the achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that, if directional indications (such as up, down, left, right, front, and rear … …) are included in the embodiments of the present invention, the directional indications are merely used to explain the relative positional relationship, movement conditions, etc. between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present invention.

In the invention, fig. 2 is a schematic diagram of an initial model state filled with polymer, first, displacement of an intermediate polymer material in the x direction is limited, and the polymer can only be filled and expanded in a groove, so that an expansion center line L (1) is obtained; when the trench structure is centered on the polymer expansion centerline, most of the filling occurs under pressure at the center (2) as shown in fig. 3;

If some smaller groove structures are arranged around the center line, the situation shown in fig. 4 will occur during bonding; wherein most of the filling still occurs at the central location (2) of the expansion centre line; while the other small structure trenches (3) are relatively less filled; it can thus be appreciated that the intermediate large structure trenches have a filler split effect, as shown in fig. 4.

Therefore, according to the principle, the invention designs an auxiliary structure which can reduce the influence of pressure on filling, and provides a filling barrier for preventing the bonding sealing blockage of the nano channel;

In a first preferred embodiment of the present invention, as shown in fig. 5, the filling barrier is a groove structure (rectangular groove) embedded in the substrate for dividing the filling amount, and is located at the center of the expansion center line generated when the bonding adhesive layer fills the micro-nano channel; the expansion center line is as follows: a line segment perpendicular to the expansion direction of the bonding adhesive layer and passing through the center point of the height of the expansion direction;

In the embodiment of the invention, a large-area structural dimension (groove structure) is manufactured near the midpoint of the expansion center line of the groove, and most of filling occurs in the filling barrier because the groove structure is positioned at the center of the expansion center line, so that the polymer filled in the useful micro-nano channel is relatively reduced, and the purpose of filling and blocking is achieved.

In the embodiment of the invention, the shape and the position of the obstruction device have certain requirements:

(1) The location of the fill barrier must be at the center of the microstructure pattern linear expansion centerline;

(2) The filling barrier must be within the same expansion centerline as the microstructure, e.g., a transverse barrier cannot serve the purpose of filling the longitudinal grooves.

(3) In order to avoid the excessive influence of the overfilling barrier on the filling size, and considering the cost of the chip, the size of the barrier should be designed according to the actual situation so as to achieve good control on the size of the micro-channel, and meanwhile, the defect of insufficient channel strength caused by too little filling of the micro-channel is avoided;

For example: the nano-groove structure needs to be sealed (the size is smaller than 100 nanometers), and a barrier with the size of 50-100 micrometers can be designed; if too large, such as a blocker size greater than 1mm, a significant amount of ineffective filling may result, not only wasting material, but also reducing seal strength;

In practical applications, the greatest difficulty is how to ensure that the microstructure pattern is on the same expansion centerline as the barrier. For a linear grating structure (a plurality of rectangular grooves parallel to each other), only the direction of the structure is required to be consistent, but for a microstructure with a complex structure, it may be very difficult to find an optimal shape of the barrier; namely, a plurality of expansion center lines in different directions are generated at the moment, the filling barrier is arranged at the center positions of all the groove structures, and a circular structure is adopted.

In a second preferred embodiment of the present invention, as shown in fig. 6, the micro-nano structure to be sealed is a two-layer ring shape; at this time, a circular baffle is arranged at the center of the inner sides of the two layers of circular rings to achieve the split filling quantity, so that top filling is restrained, and blockage is reduced during channel manufacturing.

In a third preferred embodiment of the present invention, as shown in fig. 7, the micro-nano structure to be sealed is a rectangular groove radiating outwards in circumference, and at this time, a circular barrier is arranged at the circumferential center to achieve the split filling amount, thereby suppressing top filling and reducing the occurrence of blockage during channel fabrication.

Based on the expansion centerline assumption, the further from the expansion centerline the more expansion decreases; the invention makes a series of comparison simulation, sets the distances between the grooves and the center to be 0mm,0.03mm,0.05mm,0.1mm,0.15mm,0.25mm and 0.3mm, and calculates the maximum displacement of polymer filling at different positions; thus, a relationship diagram as shown in fig. 8 is obtained; as can be seen from the figure, the maximum displacement of the polymer filling decreases with increasing distance from the center of the expansion line on the microstructure pattern, and the closer to the center the filling distance decreases in size, while the farther from the center the filling decrease increases in magnitude. From this trend, the presence of the expansion neutral line can be verified in reverse.

The foregoing description is only of the preferred embodiments of the present invention and is not intended to limit the scope of the invention, and all equivalent structural changes made by the description of the present invention and the accompanying drawings or direct/indirect application in other related technical fields are included in the scope of the invention.

Claims

1. A filling barrier for preventing nano channel bonding sealing blockage, which is characterized in that the filling barrier is a groove structure embedded in a substrate and used for dividing filling quantity and is positioned at the center of an expansion center line generated when a bonding adhesive layer fills the groove structure;

when the groove structure is a plurality of rectangular grooves which are parallel to each other, an expansion center line is generated at the moment, the filling barrier also adopts the parallel rectangular grooves, and the width of the filling barrier is larger than that of the groove structure;

the expansion center line is as follows: and a line segment perpendicular to the expansion direction of the bonding adhesive layer and passing through the center point of the height of the expansion direction.

2. The filling and blocking device for preventing nano-channel bonding and sealing blockage according to claim 1, wherein when the groove structure is a complex structure, i.e. a plurality of expansion center lines in different directions are generated at the moment, the filling and blocking device is arranged at the center position of all the groove structures.

3. The filling barrier for preventing nanochannel bonding seal occlusion of claim 2, wherein said filling barrier adopts a circular groove configuration.

4. The filling barrier for preventing nanochannel bonding seal occlusion of claim 1 or 2, wherein said trench structure is a micro-nanochannel.