CN218321637U

CN218321637U - PECVD film coating device

Info

Publication number: CN218321637U
Application number: CN202222238523.2U
Authority: CN
Inventors: 云洋; 苏建华
Original assignee: Shenzhen Aolan Technology Co ltd
Current assignee: Shenzhen Aolan Technology Co ltd
Priority date: 2022-08-24
Filing date: 2022-08-24
Publication date: 2023-01-17
Anticipated expiration: 2032-08-24

Abstract

The utility model is suitable for a coating film technical field provides a PECVD coating film device, include: the cavity is internally provided with a film coating cavity; the composite electrodes are sequentially arranged in the coating cavity at intervals, each composite electrode comprises two electrode plates which are arranged at intervals and are positive and negative, and an insulating part arranged between the two electrode plates, and the two adjacent electrode plates which respectively belong to the two adjacent composite electrodes are positive and negative and form a coating station for placing a workpiece to be coated. The utility model provides a PECVD coating device can make the electric field direction in each coating film station keep unanimous for treating in each coating film station and plating work piece coating film thickness uniformity good, and can reduce and treat to plate work piece conductivity change to electric field distribution's disturbance, ensure the different stability of treating to plate the work piece coating film.

Description

PECVD film coating device

Technical Field

The utility model relates to a coating film technical field, concretely relates to PECVD coating film device.

Background

A Plasma Enhanced Chemical Vapor Deposition (PECVD) coating apparatus ionizes a gas containing atoms of a film component by microwave or radio frequency, etc., to locally form a Plasma, and deposits a desired film on a workpiece to be coated by using the principle that the Plasma has strong Chemical activity and is easily reacted.

As shown in fig. 1, a PECVD coating apparatus in the prior art generally includes a chamber 1 having a coating chamber 11, and a plurality of single electrode plates 10 sequentially arranged at intervals in the coating chamber 11, where two adjacent single electrode plates 10 form a coating station 20 for placing a workpiece to be coated at intervals, and the plurality of single electrode plates 10 are alternately connected to a positive electrode and a negative electrode of a power supply, so that the plurality of single electrode plates are arranged in an alternating manner.

On the one hand, however, the multiple single electrode plates with the alternating positive and negative electrodes cause the electric fields of the odd-numbered workpieces to be plated (such as the

workpieces

1 and 3 to be plated in fig. 1) and the even-numbered workpieces to be plated (such as the workpieces 2 and 14 to be plated in fig. 1) to be opposite in direction, so that the thicknesses of the films deposited on the surfaces a of the odd-numbered workpieces to be plated and the surfaces a of the even-numbered workpieces to be plated are different, and the uniformity of the thicknesses of the films deposited on the workpieces to be plated is poor; on the other hand, when the conductivity of the workpiece to be plated is greatly changed, the thickness of the film deposited on the surface of the workpiece to be plated is also greatly changed. For example: when a workpiece to be plated is replaced by a metal plate from a Printed Circuit Board (PCBA), the metal plate generates relatively large disturbance to an electric field between adjacent electrode plates, and the thickness of a film deposited on the surface of the workpiece to be plated is greatly changed under the same process parameters, so that the stability of the film plating of the workpiece to be plated is poor.

SUMMERY OF THE UTILITY MODEL

The utility model provides a PECVD coating device aims at solving the problem that the PECVD coating device of prior art has the coating film thickness uniformity of waiting to plate the work piece poor, and coating film poor stability.

The utility model provides a PECVD coating device, which comprises:

the film coating device comprises a cavity, wherein a film coating cavity is arranged in the cavity; and

the composite electrodes are sequentially arranged in the coating cavity at intervals, each composite electrode comprises two electrode plates which are arranged at intervals and are mutually positive and negative, and an insulating part arranged between the two electrode plates, and the two adjacent electrode plates which respectively belong to the two adjacent composite electrodes are mutually positive and negative and form a coating station for placing a workpiece to be coated.

Preferably, one of the electrode plates of each of the composite electrodes is connected to a positive electrode of a power supply, and the other electrode plate is connected to a negative electrode of the power supply or grounded.

Preferably, the coating cavity is grounded, one of the plurality of composite electrodes close to the inner wall of the coating cavity is a positive electrode, and the one of the plurality of composite electrodes close to the inner wall of the coating cavity and the inner wall of the coating cavity form one coating station at intervals.

Preferably, the method further comprises the following steps:

the first single electrode plate is arranged in the coating cavity and positioned above the multiple composite electrodes, and the first single electrode plate and the electrode plate of the composite electrode adjacent to the first single electrode plate are positive and negative electrodes and form a coating station at intervals; and/or the presence of a gas in the gas,

and the second single electrode plate is arranged in the coating cavity and positioned below the multiple composite electrodes, and the second single electrode plate and the electrode plate of the composite electrode adjacent to the second single electrode plate are mutually positive and negative and form one coating station at intervals.

Preferably, the method further comprises the following steps:

the two supporting plates are oppositely arranged in the coating cavity at intervals, and the composite electrodes are detachably supported on the two supporting plates.

Preferably, two of the supporting plates are respectively provided with a first supporting sliding groove, and two ends of the insulating part of each composite electrode are respectively clamped into the first supporting sliding grooves of the corresponding supporting plates.

Preferably, the method further comprises the following steps:

and the workpiece supporting piece is arranged in the coating station and used for supporting the workpiece to be coated, and the workpiece supporting piece is detachably supported on the two supporting plates.

Preferably, the two support plates are respectively provided with a second support sliding groove, and two ends of each workpiece support piece are respectively clamped into the second support sliding grooves of the corresponding two support plates.

Preferably, the plurality of composite electrodes are sequentially arranged at equal intervals in parallel.

Preferably, the number of the composite electrodes is 4 to 500.

Preferably, the number of the composite electrodes is 34.

Preferably, the distance between the two electrode plates of each composite electrode is 1-1000 mm.

Preferably, the distance between the two electrode plates of each composite electrode is 20mm.

Preferably, the electrode plate is a solid metal plate, a perforated metal plate or a metal grid plate.

The utility model provides a pair of PECVD coating device is through setting up a plurality of combined electrode in the coating film intracavity, and every combined electrode includes that relative interval sets up and each other is for two plate electrodes of positive negative pole, and locate the insulating part between two plate electrodes, and two adjacent plate electrodes of two adjacent combined electrode are for positive negative pole formation electric field and interval formation coating film station to make the electric field direction in each coating film station the same. On one hand, the electric field directions in the film coating stations are kept consistent, so that the film thicknesses obtained by deposition of the workpieces to be coated in the film coating stations are kept consistent, and the film thickness consistency of the workpieces to be coated in the film coating stations is good; on the other hand, because the constant insulating part is arranged between the two electrode plates of each composite electrode, no workpiece to be plated is arranged between the two electrode plates of each composite electrode, and the distance between the two electrode plates of each composite electrode is also kept unchanged, the disturbance of electric field distribution caused by the conductivity change of the workpiece to be plated is greatly reduced, and the stability of the film plating of different workpieces to be plated is ensured.

Drawings

FIG. 1 is a schematic view of a PECVD coating apparatus in the prior art;

fig. 2 is a schematic structural diagram of a PECVD coating apparatus according to a first embodiment of the present invention;

fig. 3 is a schematic structural diagram of another PECVD coating apparatus according to an embodiment of the present invention;

fig. 4 is a three-dimensional structure diagram of a PECVD coating apparatus according to a first embodiment of the present invention;

FIG. 5 is a front view of the PECVD coating apparatus shown in FIG. 3;

FIG. 6 is an exploded perspective view of the PECVD coating apparatus shown in FIG. 3;

fig. 7 is a schematic structural view of a composite electrode of the PECVD coating device shown in fig. 3.

Fig. 8 is a schematic structural view of a PECVD coating apparatus according to a second embodiment of the present invention;

fig. 9 is a schematic structural view of a PECVD coating apparatus according to a third embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment of the utility model provides a pair of PECVD coating device is through setting up a plurality of combined electrode in the coating film intracavity, and two adjacent plate electrodes of two adjacent combined electrode are each other for positive negative pole formation electric field and interval formation coating film station, so that each electric field direction in the coating film station is the same. On one hand, the electric field directions in the film coating stations are the same, so that the film thicknesses obtained by deposition of the workpieces to be coated in the film coating stations are kept consistent, and the film coating thickness consistency of the workpieces to be coated in the film coating stations is good; on the other hand, because the constant insulating part is arranged between the two electrode plates of each composite electrode, no workpiece to be plated is arranged between the two electrode plates of each composite electrode, and the distance between the two electrode plates of each composite electrode is also kept unchanged, the disturbance of the electric field distribution caused by the conductivity change of the workpiece to be plated is greatly reduced, and the stability of the film coating of different workpieces to be plated is ensured.

Example one

Referring to fig. 2 to 6, an embodiment of the present invention provides a PECVD coating apparatus, including:

the cavity body 1 is internally provided with a coating cavity 11; and

the composite electrodes 2 are sequentially and oppositely arranged in the film coating cavity 11 at intervals, each composite electrode 2 comprises two electrode plates 21 which are oppositely arranged at intervals and are mutually positive and negative electrodes and an insulating piece 22 arranged between the two electrode plates 21, and the two adjacent electrode plates 21 which respectively belong to the two adjacent composite electrodes 2 are mutually positive and negative electrodes and form a film coating station 3 for placing a workpiece to be coated.

The embodiment of the utility model provides an in, coating film cavity 11 can ground connection, also can not ground, can set up according to the reality. Preferably, in order to improve safety, the coating chamber 11 is preferably grounded, specifically, the chamber 1 may be directly grounded.

As an embodiment of the utility model, an electrode plate 21 of every combined electrode 2 connects the positive pole of power, and another electrode plate 21 connects the negative pole or the ground connection of power for two electrode plates 21 of every combined electrode 2 are positive for one, and another is the negative pole, realizes that two electrode plates 21 are positive negative pole each other. Moreover, since the two electrode plates 21 of each composite electrode 2 are also positive and negative, the electrode plates 21 of the composite electrodes 2 are alternately arranged.

Wherein the power source can be a high frequency alternating current (RF) power source or an intermediate frequency power source (AC) and the frequency can be from 1kHz to 100MHz, and preferably the frequency is 13.56MHz. The electrode plate 21 with negative polarity can be connected to the negative polarity of the power supply or grounded, and since grounded means that the potential is zero, grounded is also a kind of negative polarity with respect to the electrode plate with positive potential.

The embodiment of the utility model provides an in, a plurality of combined electrode 2's specific quantity is not restricted, can be two, three or more than three, can carry out nimble setting according to actual need.

As an embodiment of the utility model, a plurality of combined electrode 2 in proper order equidistant parallel interval sets up, and a plurality of combined electrode 2 equidistant layering sets up in coating film chamber 11 promptly, ensures the homogeneity of the work piece coating film that treats of each coating film station 3.

The embodiment of the utility model provides an in, through set up relative spaced a plurality of combined electrode 2 in proper order in coating film chamber 11, two plate electrodes 21 of combined electrode 2 are each other for positive negative pole, and two adjacent plate electrodes 21 of two adjacent combined electrode 2 are each other for positive negative pole in order to form the electric field for the plate electrode 21 of a plurality of combined electrode 2 is positive negative pole and alternate the setting, and the electric field direction between the plate electrode 21 of two arbitrary adjacent combined electrode 2 keeps unanimous, makes the electric field direction in each coating film station 3 unanimous. Regardless of the odd-numbered workpieces to be plated (such as the workpieces to be plated 1 and 3 in fig. 2) or the even-numbered workpieces to be plated (such as the workpieces to be plated 2 and 14 in fig. 2), the electric field directions of the workpieces to be plated are the same, so that the thicknesses of films deposited on the surfaces a of the odd-numbered workpieces to be plated and the surfaces a of the even-numbered workpieces to be plated are kept consistent, the thicknesses of films deposited on the workpieces to be plated in the film plating stations 3 are kept consistent, and the thicknesses of the films deposited on the workpieces to be plated are good; on the other hand, because the constant insulating member 22 is arranged between the two electrode plates 21 of the composite electrode 2, no workpiece to be plated is arranged between the two electrode plates 21 of each composite electrode 2, and the distance between the two electrode plates 21 of each composite electrode 2 is also kept unchanged, the disturbance of the conductivity change of the workpiece to be plated on the electric field distribution is greatly reduced, the influence of replacing the workpiece to be plated with different conductivities on the electric field distribution is reduced, and the stability of the film coating of the workpiece to be plated with different materials is ensured.

The embodiment of the utility model provides an in, the plate electrode 21 of a plurality of combined electrode 2 is positive negative pole and sets up in turn, and the plate electrode 21 of a plurality of combined electrode 2 inserts power positive pole, power negative pole or ground connection in turn promptly. The positive and negative electric fields in the coating stations 3 may be sequentially and alternately arranged (as shown in fig. 2), the electric field direction in each coating station 3 is from bottom to top as indicated by the arrow in fig. 2, or the negative and positive electric fields in each coating station 3 may be sequentially and alternately arranged (as shown in fig. 3), and the electric field direction in each coating station 3 is from top to bottom as indicated by the arrow in fig. 3.

In the embodiment of the present invention, the insulating member 22 may specifically be an insulating plate or an insulating film, and the specific insulating material adopted by the insulating member 22 is not limited, such as plastic. Wherein the two electrode plates 21 of each composite electrode 2 are integrated by an insulator 22, one electrode plate 21 of each composite electrode 2 is located on the upper surface of the insulator 22, and the other electrode plate 21 is located on the lower surface of the insulator 22. The fixing manner of the two electrode plates 21 and the insulator 22 of each composite electrode 2 is not limited, and the two electrode plates and the insulator may be integrated by gluing, integral injection molding, or the like.

In the embodiment of the present invention, the two electrode plates 21 are isolated by disposing the insulating member 22 between the two electrode plates 21 of each composite electrode 2; on one hand, the waste of raw materials in the coating process caused by the discharge of the two electrode plates 21 of each composite electrode 2 due to the mutual positive and negative electric fields is avoided; on the other hand, compared with the scheme that air isolation is directly adopted between the two electrode plates 21 of each composite electrode 2, the two electrode plates 21 of each composite electrode 2 are isolated by the insulating member 22, and the distance between the two electrode plates 21 of each composite electrode 2 can be made very small, so that the utilization rate of the space in the coating cavity 11 can be improved.

As an embodiment of the utility model, the quantity of the composite electrode 2 is 4-500, ensures that the coating station 3 with enough quantity places the workpiece to be coated for coating, and improves the coating efficiency. The number of the composite electrodes 2 may be set according to actual needs, for example, may be set to 3, 10, 30, 34, 100, 200, 300, 400, 500, and the like. The composite electrodes 2 have the same structure. Two adjacent electrode plates 21 of every two adjacent composite electrodes 2 form a coating station 3 at intervals, the two adjacent electrode plates 21 of the two adjacent composite electrodes 2 are mutually positive and negative to form an electric field, and a workpiece to be coated is correspondingly placed in the coating station 3 for carrying out PECVD coating.

As a preferred embodiment of the utility model, the number of the composite electrodes 2 is 34, which not only can ensure higher coating efficiency, but also is beneficial to the miniaturization of the PECVD coating device.

As an embodiment of the present invention, the distance between the two electrode plates 21 of each composite electrode 2 is 1-1000 mm, so as to ensure that the two electrode plates 21 of each composite electrode 2 maintain good insulation.

As an embodiment of the present invention, the distance between the two electrode plates 21 of each composite electrode 2 is 20mm. The distance between the two electrode plates 21 of the composite electrode 2 is set to be 20mm, so that short circuit caused by too small distance between the two electrode plates 21 is avoided, and space waste caused by too large distance between the two electrode plates 21 is avoided.

As an embodiment of the present invention, the electrode plate 21 is a solid metal plate, a perforated metal plate or a metal grid plate.

In this embodiment, the electrode plate 21 may be a solid metal plate, a perforated metal plate, or a metal grid plate. Preferably, the electrode plate 21 is a metal plate with holes or a metal grid plate, and the holes or the grid structure on the electrode plate 21 is utilized to facilitate the diffusion of molecules, thereby being beneficial to improving the film coating efficiency of the workpiece to be plated. The electrode plate 21 may be made of any metal material, such as stainless steel, aluminum alloy, etc. In addition, the electrode plate may be surface treated, such as anodized, or may not require surface treatment.

Please refer to fig. 4-6 in combination, which are an embodiment of the present invention, further comprising:

two support plates 4 are oppositely arranged in the coating cavity 11 at intervals, and a plurality of composite electrodes 2 are detachably supported on the two support plates 4.

Specifically, both ends of the insulating member 22 of the plurality of composite electrodes 2 are detachably supported on the support plate 4, respectively.

In the embodiment, two support plates 4 are arranged in the coating cavity 11 to support the plurality of composite electrodes 2, so that the composite electrodes 2 can be fixed conveniently; moreover, the plurality of composite electrodes 2 are detachably supported on the support plate 4, so that the composite electrodes 2 are convenient to disassemble and assemble, and the composite electrodes 2 are convenient to maintain and replace; in addition, the plurality of composite electrodes 2 are convenient to disassemble and assemble, so that the positive and negative polarities of the two electrode plates 21 of the composite electrodes 2 can be flexibly replaced according to needs.

As an embodiment of the present invention, the two supporting plates 4 are respectively provided with a first supporting sliding groove 41, and the two ends of the insulating member 22 of each composite electrode 2 are respectively clamped into the first supporting sliding grooves 41 of the corresponding supporting plates 4. The first supporting chutes 41 are arranged in pairs, and each composite electrode 2 is correspondingly matched with one pair of the first supporting chutes 41.

In this embodiment, the two ends of the insulating member 22 of each composite electrode 2 are respectively clamped into the first supporting chutes 41 of the corresponding supporting plates 4, so that each composite electrode 2 can be installed in the coating cavity 11 or detached from the coating cavity 11 along the first supporting chutes 41 in a push-pull manner, thereby facilitating the assembly and disassembly of the composite electrodes 2 and saving time and labor in operation.

As an embodiment of the utility model, still include:

and the workpiece support piece 5 is arranged in the coating station 3 and used for supporting the workpiece to be coated, and the workpiece support piece 5 is detachably supported on the two support plates 4.

In the embodiment, a workpiece support part 5 is arranged in the coating station 3 and used for supporting a workpiece to be coated, and the workpiece to be coated is placed on the workpiece support part 5 for coating; and the workpiece support piece 5 is detachably supported on the support plate 4, so that the workpiece support piece 5 is convenient to disassemble and assemble, the workpiece to be plated is convenient to take and place, and meanwhile, the workpiece support piece 5 is convenient to replace. The workpiece support 5 may be a plate-like structure, a frame structure, or other structures.

As an embodiment of the present invention, the two supporting plates 4 are respectively provided with a second supporting sliding groove 42, and the two ends of each workpiece supporting member 5 are respectively clamped into the second supporting sliding grooves 42 of the two corresponding supporting plates 4. Wherein the second supporting slide grooves 42 are provided in pairs, and each of the workpiece supports 5 is correspondingly engaged with a pair of the second supporting slide grooves 42.

In this embodiment, the workpiece support member 5 is matched with the second supporting chutes 42 of the two supporting plates 4, so that the workpiece support member 5 can be installed in the coating station 3 along the second supporting chutes 42 in a push-pull manner, which is convenient for the detachment and installation of the workpiece support member 5.

Example two

Referring to fig. 8, on the basis of the first embodiment, the film coating cavity 11 is grounded, one electrode plate 21 of the multiple composite electrodes 2 close to the inner wall of the film coating cavity 11 is a positive electrode, and one electrode plate 21 close to the inner wall of the film coating cavity 11 and the inner wall of the film coating cavity 11 form a film coating station 3 at an interval.

In this embodiment, set up one of a plurality of combined electrode 2 to be anodal near the electrode plate 21 of coating film cavity 11 inner wall, and because coating film cavity 11 ground connection, coating film cavity 11 inner wall can regard as the negative pole, thus can form a coating film station 3 of placing the work piece that treats plating between the electrode plate 21 that is close to coating film cavity 11 inner wall and the coating film cavity 11 inner wall, can utilize coating film cavity 11 inner wall as the negative pole ingeniously, under the prerequisite that need not increase electrode plate 21, can increase coating film station 3 and place the work piece coating film that treats plating, promote coating film efficiency, and need not to increase the cost.

EXAMPLE III

Referring to fig. 4-7 and 8, in the first embodiment, the PECVD coating apparatus further includes:

the first single electrode plate 6 is arranged in the film coating cavity 11 and positioned above the plurality of composite electrodes 2, and the first single electrode plate 6 and the electrode plate 21 of the adjacent composite electrode 2 are mutually positive and negative and form a film coating station 3 at intervals; and/or the presence of a gas in the gas,

and the second single electrode plate 7 is arranged in the film coating cavity 11 and positioned below the plurality of composite electrodes 2, and the second single electrode plate 7 and the electrode plate 21 of the adjacent composite electrode 2 are positive and negative electrodes and form a film coating station 3 at intervals.

In this embodiment, the first single electrode plate 6 and the second single electrode plate 7 may be provided at the same time, or only one of them may be provided. Preferably, the first single electrode plate 6 and the second single electrode plate 7 may be simultaneously disposed.

In this embodiment, a workpiece support 5 is provided in each coating station 3. The first single electrode plate 6 and the second single electrode plate 7 are each a single electrode plate, and the electric polarity thereof may be determined according to the electrode plate 21 of the adjacent composite electrode 2. For example, if the electrode plate 21 of the adjacent composite electrode 2 of the first single electrode plate 6 is a positive electrode, the first single electrode plate 6 is a negative electrode; the electrode plate 21 of the adjacent composite electrode 2 of the first single electrode plate 6 is a negative electrode, and the first single electrode plate 6 is a positive electrode; the electrode plate 21 of the adjacent composite electrode 2 of the second single electrode plate 7 is a positive electrode, and the second single electrode plate 7 is a negative electrode; the electrode plate 21 of the adjacent composite electrode 2 of the second single electrode plate 7 is a negative electrode, and the second single electrode plate 7 is a positive electrode.

In this embodiment, an electric field is formed by the first single electrode plate 6 and the uppermost electrode plate 21 of the plurality of composite electrodes 2, which are positive and negative, and a coating station 3 is formed between the first single electrode plate 6 and the electrode plate 21 of the composite electrode 2 at intervals; an electric field is formed by the mutual positive and negative of the second single electrode plate 7 and the lowest electrode plate 21 of the multiple composite electrodes 2, and a coating station 3 is formed between the second single electrode plate 7 and the electrode plate 21 of the composite electrode 2 at intervals. Therefore, the first single electrode plate 6 and the second single electrode plate 7 can be used for replacing one composite electrode 2 respectively, the coating stations 3 can be added above the multiple composite electrodes 2 only by arranging one single electrode plate to be paired with the uppermost composite electrode 2, the coating stations 3 can be added below the multiple composite electrodes 2 by arranging one single electrode plate to be paired with the lowermost composite electrode 2, the coating stations 3 can be added at low cost, the coating efficiency is improved, the number of the electrode plates 21 is reduced, and the cost is reduced. In addition, this embodiment can also be understood that only one electrode plate 21 needs to be reserved for each of the two composite electrodes 2 located at the uppermost position and the lowermost position near the inner wall of the coating chamber 11, which does not affect the coating efficiency and can reduce the cost.

In order to prove the technical effect obtained by the utility model, the PECVD coating device is utilized to carry out four groups of experimental groups and four groups of contrast groups are proved by utilizing the traditional PECVD coating device. Wherein, the experimental group 1-4 adopts the PECVD coating device of the utility model, and the contrast group 1-4 adopts the traditional PECVD coating device.

Experimental group 1 (monomer gas is ethylene, workpiece to be plated is PCBA)

1) Placing the PCBA board in the film coating cavity 11, vacuumizing to 30 mTorr, introducing monomer gas, wherein the monomer is ethylene, and placing silicon wafers on the upper surface (surface A) and the lower surface (surface B) of the PCBA board respectively for measuring the thickness of the coating; and adhering double-sided adhesive tape to the back of the silicon wafer to fix the silicon wafer on the PCBA. Wherein, the electrode plate configuration in the coating cavity 11 is as shown in fig. 3;

2) Starting plasma discharge to carry out chemical vapor deposition, carrying out radio frequency discharge by adopting radio frequency alternating current with power supply energy of 13.56MHz, wherein the power is 500W, the output mode is continuous constant discharge, and the total deposition time is 1-30min;

3) Closing the radio frequency, introducing air to enable the pressure inside and outside the coating cavity 11 to be balanced to 1 atmosphere, opening a coating cavity door, and taking out the PCBA and the silicon wafer; the thickness of the coating on the silicon wafer was measured with an ellipsometer, and the measured data are shown in table 1; the average thickness of the surface A film of each workpiece to be plated is 506nm, and the standard deviation of the thickness of the surface A film of each workpiece to be plated is 19nm; the average thickness of the B surface film of each workpiece to be plated is 351nm, and the standard deviation of the film thickness of the B surface of each workpiece to be plated is 17nm.

TABLE 1

Numbering of workpieces to be plated	Thickness of A surface (nm)	Thickness of B surface (nm)
			1	510	350
2	525	365
			3	500	353
4	501	352
			5	488	340
6	478	330
			7	523	368
8	530	371
			9	510	352
10	505	351
			11	470	320
12	480	315
			13	510	360
14	515	366
			15	530	367
16	528	361

Experimental group 2 (monomer gas is ethylene, workpiece to be plated is aluminum plate)

Experimental group 2 is substantially the same as experimental group 1 except that: experiment group 2 replaces PCBA board with aluminum plate, and the thickness of coating is measured to the fixed silicon chip of aluminum plate upper and lower surface. All other process parameters are kept unchanged, the film thickness change caused by the change of the material of the workpiece to be plated is measured, and the measured data is shown in a table 2; the average film thickness of the surface A of each workpiece to be plated is calculated to be 519nm, and the standard deviation of the film thickness of the surface A of each workpiece to be plated is 21nm; the average film thickness of the B surface of each workpiece to be plated is 362nm, and the standard deviation of the film thickness of the B surface of each workpiece to be plated is 15nm.

TABLE 2

Experiment group 3 (monomer gas is 2-perfluorooctyl ethyl acrylate, workpiece to be plated is PCBA)

1) Placing the PCBA plate in the film coating cavity 11, vacuumizing to 80 mTorr, introducing monomer steam, wherein the monomer is 2-perfluorooctyl ethyl acrylate, and placing silicon wafers on the upper surface (surface A) and the lower surface (surface B) of the PCBA respectively for measuring the thickness of the coating. And adhering double-sided adhesive tape to the back of the silicon wafer to fix the silicon wafer on the PCBA. The electrode plate configuration in the coating cavity 11 is shown in fig. 2;

2) Starting plasma discharge to carry out chemical vapor deposition, carrying out radio frequency discharge by adopting radio frequency alternating current with power supply energy of 13.56MHz, wherein the power is 500W, the output mode is pulse output (the pulse width is 40ms, the frequency is 50 Hz), and the total deposition time is 0.5-3.0 h;

3) Closing the radio frequency, introducing air to enable the internal pressure and the external pressure of the film coating cavity 11 to be balanced to 1 atmosphere, opening the door of the film coating cavity 11, and taking out the PCBA and the silicon wafer; measuring the thickness of the coating on the silicon wafer, wherein the measured data are shown in table 3; wherein the average film thickness of the A surface of each workpiece to be plated is 507nm, and the standard deviation of the film thickness of the A surface of each workpiece to be plated is 29nm; the average film thickness of the B surface of each workpiece to be plated is 530nm, and the standard deviation of the film thickness of the B surface of each workpiece to be plated is 30nm.

TABLE 3

Experimental group 4 (monomer gas is 2-perfluorooctyl ethyl acrylate, and workpiece to be plated is aluminum plate)

Experimental group 4 is substantially the same as experimental group 3 except that: replacing the PCBA board with an aluminum plate, fixing silicon wafers on the upper surface and the lower surface of the aluminum plate, and measuring the thickness of the coating. All other process parameters are kept unchanged, the film thickness change caused by the material change of the workpiece to be plated is measured, and the measured data are shown in a table 4; the average film thickness of the A surface of each workpiece to be plated is 514nm, and the standard deviation of the film thickness of the A surface of each workpiece to be plated is 30nm; the average film thickness of the B surface of each workpiece to be plated is 518nm, and the standard deviation of the film thickness of the B surface of each workpiece to be plated is 32nm.

TABLE 4

Numbering of workpieces to be plated	Thickness of A surface (nm)	Thickness of B surface (nm)
			1	525	530
2	550	559
			3	523	530
4	519	534
			5	490	490
6	460	459
			7	530	535
8	526	530
			9	530	524
10	523	530
			11	460	470
12	459	459
			13	512	520
14	531	523
			15	533	540
16	549	559

Control group 1 (monomer gas is ethylene, workpiece to be plated is PCBA)

The comparison group 1 is basically the same as the experiment group 1, and is different in that the comparison group 1 adopts a traditional single-electrode-plate PECVD coating device, the experimental steps of the embodiment 1 are repeated, and the measured data are shown in table 5, wherein the average film thickness of the A surface of each workpiece to be coated is 428nm, and the standard deviation of the film thickness of the A surface of each workpiece to be coated is 82nm; the average film thickness of the B surface of each workpiece to be plated is 427nm, and the standard deviation of the film thickness of the B surface of each workpiece to be plated is 85nm.

TABLE 5

Numbering of workpieces to be plated	Thickness of A surface (nm)	Thickness of B surface (nm)
			1	511	348
2	363	530
			3	490	343
4	350	501
			5	498	339
6	330	478
			7	523	358
8	368	530
			9	510	352
10	351	505
			11	472	320
12	315	478
			13	505	362
14	366	512
			15	532	350
16	361	528

Control group 2 (monomer gas is ethylene, workpiece to be plated is aluminum plate)

Control group 2 is substantially the same as experimental group 2 except that: the control group 2 adopts a traditional single-electrode-plate PECVD coating device, the experimental steps of the experimental group 2 are repeated, and the measured data are shown in table 6, wherein the average film thickness of the surface A of each workpiece to be coated is 536nm, and the standard deviation of the film thickness of the surface A of each workpiece to be coated is 103nm; the average film thickness of the B surface of each workpiece to be plated is 533nm, and the standard deviation of the film thickness of the B surface of each workpiece to be plated is 106nm.

TABLE 6

Control group 3 (monomer gas is 2-perfluorooctyl ethyl acrylate, and workpiece to be plated is PCBA)

The control group 3 is substantially the same as the experimental group 3 except that: the control group 3 adopts a traditional single-electrode-plate PECVD coating device, the experimental steps of the experimental group 3 are repeated, and the measured data are shown in table 7, wherein the average film thickness of the A surface of each workpiece to be coated is 544nm, and the standard deviation of the film thickness of the A surface of each workpiece to be coated is 51nm; the average film thickness of the B surface of each workpiece to be plated is 539nm, and the standard deviation of the film thickness of the B surface of each workpiece to be plated is 57nm.

TABLE 7

Control group 4 (monomer gas is 2-perfluorooctyl ethyl acrylate, workpiece to be plated is aluminum plate)

Control group 4 was substantially the same as experimental group 4 except that: the control group 4 adopts a traditional single-electrode-plate PECVD coating device, the experimental steps of the experimental group 4 are repeated, and the measured data are shown in table 8, wherein the average film thickness of the surface A of each workpiece to be coated is 622nm, and the standard deviation of the film thickness of the surface A of each workpiece to be coated is 58nm; the average film thickness of the B surface of each workpiece to be plated is 614nm, and the standard deviation of the film thickness of the B surface of each workpiece to be plated is 67nm.

TABLE 8

Numbering of workpieces to be plated	Thickness of A face (nm)	Thickness of B surface (nm)
			1	590	670
2	691	600
			3	587	684
4	700	560
			5	550	605
6	580	470
			7	600	689
8	670	590
			9	610	690
10	699	560
			11	520	605
12	590	513
			13	580	670
14	670	592
			15	605	700
16	703	620

According to the analysis of the experimental data of the experimental groups 1-4 and the control groups 1-4, the following results can be obtained:

on the one hand, the PECVD film coating device can ensure that the thickness of the same surface of the whole furnace to be coated is more consistent.

For example, when the monomer gas is ethylene, the thickness of the A surface of the PCBA to be plated in the experimental group 1 is 506nm on average, and the standard deviation of the thickness of the A surface is 19nm; the thickness of the A surface of the workpiece PCBA to be plated in the control group 1 is 428nm on average, and the standard deviation of the thickness of the A surface is 82nm. It can be seen that the thickness consistency of the A surface of the PCBA to be plated is better than that of the traditional 4.3 times. Because the conventional single electrode plate 21 configuration, the direction of the electric field received by the a-face of one half of the PCBA is exactly opposite to the direction of the electric field received by the a-face of the other half of the PCBA, resulting in an average thickness of 505nm for the a-face of one half of the PCBA and an average thickness of 305nm for the a-face of the other half of the PCBA, which differs by a factor of 1.7.

For another example, when the monomer was ethyl 2-perfluorooctyl acrylate, the PCBA of the workpiece to be plated in Experimental group 3 had an average thickness of 507nm and a standard deviation of thickness of the A face of 29nm. The average thickness of the surface A of the workpiece to be plated PCBA in the control group 3 is 544nm, the standard deviation of the thickness of the surface A is 51nm, and it can be seen that the thickness consistency of the surface A of the workpiece to be plated PCBA is better than that of the traditional 1.8 times. Because of the conventional single electrode plate configuration, the direction of the electric field received by the a-face of one half of the PCBA is exactly opposite to the direction of the electric field received by the a-face of the other half of the PCBA.

Among these, the effect is more pronounced when the monomer gas is ethylene, because ethylene is a gas at room temperature, and if it is not ionized (i.e., a neutral precursor), it is easily pumped away and does not deposit a film. Therefore, in the film obtained by ethylene PECVD, the charged precursor plays a larger role, and the charged precursor is obviously influenced by the direction of an electric field, so that ethylene is more sensitive.

Wherein, the 2-perfluorooctyl ethyl acrylate is liquid at normal temperature, and the saturated vapor pressure is lower than that of ethylene. The proportion of the neutral precursor which is adhered to the surface of the workpiece to be plated is obviously higher than that of ethylene. Therefore, the sensitivity of 2-perfluorooctyl ethyl acrylate to the direction of the electric field is lower. However, the effect of the present invention is still significant.

On the other hand, according to the experimental data of the experimental groups 1-4 and the comparison group 1-4, the electric field of the PECVD coating device is less affected by the conductivity change of the workpiece to be coated, and the stability of the coating of the workpiece to be coated is better. When the workpiece to be plated is changed from the non-conductive PCBA to the conductive aluminum plate, the thickness stability of the plated film is better.

For example, when the monomer is ethylene, the

experimental groups

1 and 2 of the present invention show that: when the workpiece to be plated is changed from PCBA in the experimental group 1 to aluminum plate in the experimental group 2, the thickness of the plated film is changed by less than 3%.

The

comparison groups

1 and 2 of the conventional single electrode plate PECVD coating device show that: when the workpiece to be plated was changed from PCBA in comparative example 1 to aluminum plate in control 2, the thickness of the plated film varied by as much as 25%.

As another example, when the monomer was ethyl 2-perfluorooctyl acrylate, experimental groups 3 and 4 showed that the thickness of the plated film varied by only less than 2% when the workpiece to be plated was changed from PCBA to aluminum.

And the control groups 3 and 4 of the conventional single electrode plate PECVD coating device show that: the change of the coating thickness reaches up to 15 percent, because the composite electrode used by the utility model ensures that each electrode plate in the coating cavity has a self-pairing electrode plate, a constant medium is arranged between the two electrode plates paired by the composite electrode, and a workpiece to be coated does not exist between the pairing electrode plates; and the counter electrode plate spacing is also kept constant. Compared with the traditional PECVD coating device with a single electrode plate, the disturbance on the electric field distribution caused by the conductivity change of the workpiece to be coated is much smaller. In the conventional situation, workpieces to be plated are arranged above and/or below each electrode plate, and the electric conductivity change of the workpieces to be plated causes the electric charges accumulated on the surfaces of the workpieces to be plated in the deposition process to be greatly changed, so that the disturbance on an electric field is large, and the poor film plating stability of the workpieces to be plated of different materials is caused.

The precursor used for the plating is a chemically reactive substance formed by activating a chemical material molecule used for the plating with plasma, and may be a neutral molecule, atom or radical, or a positively charged cation or negatively charged anion formed by ionizing with plasma. Neutral precursors are not affected by the direction of the electric field, charged precursors are affected by the direction of the electric field. When the proportion of the neutral precursor is high and the proportion of the electrification is low, the coating consistency and the stability are relatively good; however, when the neutral proportion is low and the charged proportion is high, the uniformity and stability are relatively poor, and the PECVD coating device of the utility model can ensure that the coating of the workpiece to be coated has good uniformity and stability no matter under which condition because the electric field directions of all coating stations are the same.

The above description is only exemplary of the present invention and should not be construed as limiting the present invention, and any modifications, equivalents and improvements made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. A PECVD coating device is characterized by comprising:

the composite electrodes are sequentially arranged in the coating cavity at intervals, each composite electrode comprises two electrode plates which are arranged at intervals and are mutually positive and negative, and an insulating part arranged between the two electrode plates, and the insulating parts respectively belong to two adjacent electrode plates of the composite electrodes, which are mutually positive and negative and form a coating station for placing a workpiece to be coated.

2. The PECVD coating device of claim 1, wherein one of said electrode plates of each of said composite electrodes is connected to the positive terminal of a power supply, and the other of said electrode plates is connected to the negative terminal of said power supply or grounded.

3. The PECVD coating device of claim 1, wherein the coating chamber is grounded, one of the plurality of composite electrodes close to the inner wall of the coating chamber is a positive electrode, and the one of the plurality of composite electrodes close to the inner wall of the coating chamber is spaced from the inner wall of the coating chamber to form one coating station.

4. The PECVD coating device of claim 1, further comprising:

the first single electrode plate is arranged in the coating cavity and positioned above the multiple composite electrodes, and the first single electrode plate and the electrode plate of the composite electrode adjacent to the first single electrode plate are mutually positive and negative and form a coating station at intervals; and/or the presence of a gas in the atmosphere,

5. A PECVD coating device according to claim 1, further comprising:

6. A PECVD coating device as claimed in claim 5, wherein two of the supporting plates are respectively provided with a first supporting sliding groove, and two ends of the insulating part of each composite electrode are respectively clamped into the first supporting sliding grooves of the corresponding supporting plates.

7. A PECVD coating device according to claim 5, characterized in that it further comprises:

8. A PECVD coating device according to claim 7, wherein two supporting plates are respectively provided with a second supporting sliding groove, and two ends of each workpiece supporting piece are respectively clamped in the second supporting sliding grooves of the two corresponding supporting plates.

9. A PECVD coating device according to claim 1, characterized in that a plurality of said composite electrodes are arranged in sequence at equal intervals in parallel.

10. A PECVD coating device according to claim 1, characterized in that the number of the composite electrodes is 4-500.

11. A PECVD coating device according to claim 10, characterized in that the number of the composite electrodes is 34.

12. A PECVD coating device according to claim 1, characterized in that the distance between the two electrode plates of each composite electrode is 1-1000 mm.

13. A PECVD coating device according to claim 12, characterized in that the distance between the two electrode plates of each composite electrode is 20mm.

14. A PECVD coating device according to claim 1, characterized in that the electrode plate is a solid metal plate, a perforated metal plate or a metal grid plate.