CN115209636A

CN115209636A - Internal circulation high-speed jet printing head applied to PCB or FPC character jet printing equipment

Info

Publication number: CN115209636A
Application number: CN202210955670.3A
Authority: CN
Inventors: 吴圣猛; 吴旭东; 黄智程
Original assignee: Shenzhen Dongyisheng Technology Co ltd
Current assignee: Shenzhen Dongyisheng Technology Co ltd
Priority date: 2022-08-10
Filing date: 2022-08-10
Publication date: 2022-10-18

Abstract

The invention provides an internal circulation high-speed jet printing head applied to Printed Circuit Board (PCB) or Flexible Printed Circuit (FPC) character jet printing equipment, wherein a first fluid groove and a second fluid groove are formed in a first plane of a substrate, and a plurality of communication grooves are formed between the first fluid groove and the second fluid groove; a plane groove communicated with the communicating groove is concavely arranged on the second plane of the substrate, the first plane covers the upper cover plate, and the upper cover plate is provided with a first piezoelectric crystal corresponding to the communicating groove; a lower cover plate is embedded in the plane groove of the second plane, and micropores and second piezoelectric crystals corresponding to the communicating grooves are arranged on the lower cover plate; the first and second piezoelectric crystals are configured to: the first piezoelectric crystal and the second piezoelectric crystal deform in opposite ways when an electric field is applied. When the first piezoelectric crystal and the second piezoelectric crystal deform into the communicating groove from the upper end and the lower end of the communicating groove, the ink is extruded more, and the requirements of the PCB character ink-jet printer on high ink amount and higher jet printing speed are met.

Description

Internal circulation high-speed jet printing head applied to PCB or FPC character jet printing equipment

Technical Field

The invention relates to the technical field of Printed Circuit Board (PCB) character jet printing, in particular to an internal circulation high-speed jet printing head applied to PCB or flexible printed circuit board (FPC) character jet printing equipment.

Background

With the updating iteration speed of electronic products becoming faster and faster, the demand for the yield of PCB/FPC also becomes higher and higher.

The traditional PCB manufacturing method is mainly based on a screen printing process and can not meet the production requirements of modern PCBs gradually, the ink-jet printing technology is used as a novel technology and can be directly used for jet printing anti-corrosion and anti-plating patterns and printing characters, even jet printing lines, compared with the traditional screen printing process, the PCB ink-jet printer utilizing the ink-jet printing technology completely accords with the development direction of industrial policies of energy conservation, emission reduction, consumption reduction and efficiency enhancement, and is gradually called as the mainstream of PCB production.

The application of the PCB ink-jet printer in PCB production is mainly in the aspects of pattern transfer, embedding passive elements and directly forming conductive circuits, and in the application of the PCB pattern transfer, character jet printing is a mature application. The existing ink jet printer for PCB characters uses piezoelectric type nozzles. When a voltage having image information is applied to the head, the volume of a device for storing liquid in the head changes abruptly, and ink is ejected from a fixed orifice, thereby forming characters on a circuit board.

The piezoelectric type spray head is applied to an internal circulation technology, namely, ink flows in a channel in a circulation mode so as to prevent pigment particles in the nozzle from depositing and blocking the nozzle, a piezoelectric crystal is arranged on the side wall or the end part of the channel, and when ink drops need to be sprayed, an electric field is applied to the piezoelectric crystal to drive the piezoelectric crystal to deform, so that the ink in the channel is extruded out of the nozzle and sprayed on a PCB substrate.

PCB characters compare with wire circuit, require lower, and the ink volume that consumes is many, and require printing speed, however, printing ink generally has viscidity, and when printing ink high-speed flow in the passageway, the piezoelectric crystal need give printing ink bigger power when extrudeing to high-speed flowing printing ink, just can inject printing ink from the nozzle fast effectively, and current shower nozzle is not fine the high-speed jet printing of a large amount of printing ink yet, consequently needs the improvement.

Disclosure of Invention

The invention provides an internal circulation high-speed jet printing head applied to PCB or FPC character jet printing equipment, which meets the requirements of a PCB character ink jet printer on high ink quantity and higher jet printing speed.

The technical scheme of the invention is as follows:

an internal circulation high-speed jet printing head applied to a PCB or FPC character jet printing device comprises:

the substrate is provided with a first plane and a second plane, the first plane is provided with a first fluid groove and a second fluid groove, a plurality of communication grooves which are arranged along the length direction of the first fluid groove and the second fluid groove are arranged between the first fluid groove and the second fluid groove, and the second plane is provided with a plane groove which is communicated with each communication groove;

the upper cover plate covers the first plane, and the surface of the upper cover plate, which is deviated from the first plane, is provided with first piezoelectric crystals which correspond to the communication grooves one to one;

the upper cover plate covers the plane groove, micropores communicated with the communicating grooves in a one-to-one correspondence mode are formed in the upper cover plate, and second piezoelectric crystals corresponding to the communicating grooves in a one-to-one correspondence mode are arranged on the surface, away from the plane groove, of the upper cover plate;

the first and second piezoelectric crystals are configured to: when an electric field is applied, the first piezoelectric crystal and the second piezoelectric crystal deform in opposite ways.

In some embodiments of the present invention, there are two micro holes corresponding to each of the communication grooves, there are two first piezoelectric crystals corresponding to each of the communication grooves, and the first piezoelectric crystals correspond to the micro holes.

In some embodiments of the present invention, the length of the communication groove is 10mm to 20mm, and the distance between two micro holes corresponding to the same communication groove is 5mm to 10mm.

In some embodiments of the present invention, a central axis of the micro hole intersects a deformation central line of the first piezoelectric crystal.

In some embodiments of the invention, the squeezing force of the first piezoelectric crystal against the ink is greater than the squeezing force of the second piezoelectric crystal when the electric field is applied.

In some embodiments of the present invention, the ratio of young's modulus of the upper cover plate to the lower cover plate is greater than 1.

In some embodiments of the present invention, the upper cover plate is made of any one of polyimide, polyamide, or polyetheretherketone, and the lower cover plate is made of polytetrafluoroethylene.

In some embodiments of the present invention, the upper cover plate has a thickness of 70 to 150 micrometers and the lower cover plate has a thickness of 50 to 70 micrometers.

In some embodiments of the invention, the sum of the thicknesses of the lower cover plate and the second piezoelectric crystal is less than the depth of the planar slot.

In some embodiments of the invention, the inkjet head further includes a base on which a first face of the base is engaged, having an avoidance groove that avoids the upper cover plate, and an ink inlet chamber and an ink return chamber that communicate with the first fluid groove and the second fluid groove.

The invention has the beneficial effects that:

providing a first fluid groove and a second fluid groove on a first plane of a substrate, and providing a plurality of communication grooves between the first fluid groove and the second fluid groove; a plane groove corresponding to the communicating groove is concavely arranged on the second plane of the substrate, the upper cover plate is covered on the first plane, and a first piezoelectric crystal corresponding to the communicating groove is arranged on the upper cover plate; a lower cover plate is embedded in the plane groove of the second plane, and micropores and second piezoelectric crystals corresponding to the communicating grooves are arranged on the lower cover plate; and, configuring the first and second piezoelectric crystals to: the first piezoelectric crystal and the second piezoelectric crystal deform in opposite ways when an electric field is applied. Therefore, when jet printing is carried out, an electric field can be applied to the first piezoelectric crystal and the second piezoelectric crystal, so that the first piezoelectric crystal and the second piezoelectric crystal deform towards the inside of the channel, ink is ejected out of the channel in a pressing mode, due to the fact that the upper end and the lower end of the channel are extruded, the extrusion of the inner part of the channel is larger, more ink can be ejected out of the channel in a pressing mode more quickly, and the requirements of a PCB character ink jet printer on high ink amount and higher jet printing speed are met.

And compared with the traditional side jet printing structure in which the piezoelectric crystal is arranged on the inner side wall of the groove, the structure provided by the invention is more convenient to implement, specifically, during manufacturing, the whole piezoelectric crystal can be bonded on the upper cover plate and the lower cover plate, then the piezoelectric crystal is cut to form independent piezoelectric units, and then the cover plate is bonded on the communication groove to close the communication groove to form the communication channel, so that the manufacturing difficulty of the jet printing head is greatly reduced.

Drawings

Fig. 1 is an exploded view of an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a substrate according to an embodiment of the invention.

Fig. 3 is another schematic structural diagram of a substrate according to an embodiment of the invention.

Fig. 4 is a schematic diagram of the upper cover plate and the base in an embodiment of the invention.

Fig. 5 is a schematic structural diagram of a base according to an embodiment of the invention.

FIG. 6 is a schematic view of the flow of ink in one embodiment of the present invention.

FIG. 7 is another schematic flow diagram of ink in an embodiment of the invention.

Fig. 8 isbase:Sub>A partial cross-sectional view taken atbase:Sub>A-base:Sub>A of fig. 6.

FIG. 9 is a schematic view of ink ejection in one embodiment of the invention.

FIG. 10 is another schematic view of ink ejection according to an embodiment of the present invention

Fig. 11 is a partial cross-sectional view at B-B in fig. 6.

FIG. 12 is a schematic diagram of a first piezoelectric crystal ejecting ink in a channel in accordance with one embodiment of the present invention.

FIG. 13 is a schematic diagram of two first piezo ejecting ink from a channel according to one embodiment of the present invention.

Detailed Description

The invention is described in detail below with reference to the figures and the specific embodiments.

As shown in fig. 1, the inner loop high speed inkjet printhead applied to PCB or FPC character inkjet printing apparatus according to the present invention includes a substrate 10, an upper cover plate 20 and a lower cover plate 30.

As shown in fig. 2, the substrate 10 has a first plane and a second plane parallel to each other in the Z-axis direction, the first plane is provided with a first fluid groove 10b and a second fluid groove 10c along the Y-axis, the first fluid groove 10b and the second fluid groove 10c have a certain interval in the X-axis, and the interval region is provided with a plurality of communication grooves 10f aligned along the Y-axis. Each of the communication grooves 10f is provided along the X axis to communicate the first fluid groove 10b with the second fluid groove 10 c. Therefore, as shown in fig. 6, when ink is introduced into the first fluid groove, the ink in the first fluid groove flows to the second fluid groove through the communication grooves, and the first fluid groove and the second fluid groove are communicated with the ink cartridge connected with the print head, so that a circulation loop can be formed, the ink in the print head can always keep a flowing state in the print head, and the blockage caused by the deposition of particulate matter in the ink in the fluid groove or the communication grooves is avoided.

As shown in fig. 4, the upper cover plate 20 covers the first plane, and closes the notches of the first fluid groove, the second fluid groove, and the communication groove, which are open to the outside along the Z-axis, to form the first fluid passage, the communication passage, and the second fluid passage on the substrate 10. As shown in fig. 8, the surface of the upper cover plate 20 facing away from the first plane is provided with first piezoelectric crystals 22 corresponding to the communication grooves one by one, the first piezoelectric crystals 22 are located right above the communication grooves, and the upper cover plate body between adjacent first piezoelectric crystals 22 is bonded to the end of the groove wall 10e of the communication groove to support the first piezoelectric crystals 44.

It should be noted that, for the convenience of showing the groove body structure of the base plate 10, portions of the upper cover plate 20 covering both ends of the first fluid groove, the second fluid groove, and the communication groove are not shown.

As shown in fig. 3, a flat groove 10g is recessed in the second plane along the Z axis, and the flat groove 10g communicates with each of the communication grooves such that a bottom notch of each communication groove is exposed outward from the flat groove 10 g. The width of the plane groove 10g is less than the length of the communicating groove, and is about 2/3 of the length of the communicating groove, so that two ends of the groove wall of the communicating groove are connected with the substrate body, and the connecting groove is not separated from the substrate body due to the opening of the plane groove.

The lower cover plate is embedded in the plane groove to close the bottom notches of the communication grooves, so that a plurality of communication channels arranged along the Y axis are formed on the substrate. At least one micropore is arranged on the lower cover plate corresponding to each communicating groove, so that the ink in the communicating channel can be ejected from the inside and the outside of the channel. In order to drive the ink to be ejected outwards from the channel, as shown in fig. 8, second piezoelectric crystals 32 corresponding to the communication grooves one by one are arranged on the surface of the lower cover plate 30, which is far away from the planar grooves. As shown in fig. 11, a portion of the second piezoelectric crystal 32 opposite to the micropore is cut away to avoid the micropore.

In addition, the first piezoelectric crystal and the second piezoelectric crystal are configured to: when an electric field is applied, the first piezoelectric crystal and the second piezoelectric crystal deform in opposite ways. Specifically, after an electric field is applied, the middle part of the first piezoelectric crystal can be concave inwards to the communication channel, and the middle part of the second piezoelectric crystal can be convex inwards to the communication channel, so that the upper cover plate and the lower cover plate are extruded to deform towards the inside of the communication channel, ink of the communication channel is pressed, and the ink is injected out of the communication channel.

In the high-speed inkjet head, a first fluid groove and a second fluid groove are formed in a first plane of a substrate, and a plurality of communication grooves are formed between the first fluid groove and the second fluid groove; a plane groove corresponding to the communication groove is concavely arranged on the second plane of the substrate, the upper cover plate covers the first plane, and a first piezoelectric crystal corresponding to the communication groove is arranged on the upper cover plate; a lower cover plate is embedded in the plane groove of the second plane, and micropores and second piezoelectric crystals corresponding to the communicating grooves are arranged on the lower cover plate; and, configuring the first and second piezoelectric crystals to: the first piezoelectric crystal and the second piezoelectric crystal deform in opposite ways when an electric field is applied. Therefore, when jet printing is carried out, an electric field can be applied to the first piezoelectric crystal and the second piezoelectric crystal, so that the first piezoelectric crystal and the second piezoelectric crystal deform towards the inside of the channel, ink is ejected out of the channel in a pressing mode, due to the fact that the upper end and the lower end of the channel are extruded, the extrusion of the inner part of the channel is larger, more ink can be ejected out of the channel in a pressing mode more quickly, and the requirements of a PCB character ink jet printer on high ink amount and higher jet printing speed are met.

In the above embodiments, the first piezoelectric crystal and the second piezoelectric crystal may be selectively driven to deform the first piezoelectric crystal and/or the second piezoelectric crystal as needed to control the amount of ejection. For example, as shown in FIG. 9, it may be selected to apply an electric field to only the first piezoelectric crystal 22, such that the first piezoelectric crystal 22 deforms into the communication channel, ejecting a small amount of ink liquid. Alternatively, as shown in FIG. 10, an electric field is applied to the first and second

piezoelectric crystals

22 and 32, compressing the space of the communicating channels to a greater extent and injecting more of the ink liquid. Through the cooperation of the first piezoelectric crystal 22 and the second piezoelectric crystal 32, each micropore has more selectable jet printing quantity and faster jet printing response, so that the high-speed jet printing requirements of different ink quantities are met.

Preferably, as shown in fig. 11, in the above embodiment, the micro holes corresponding to each of the communication grooves 10f are provided in two, and accordingly, the first piezoelectric crystals (21, 22) corresponding to each of the communication grooves 10f are also provided in two, and the first piezoelectric crystals (21, 22) correspond to the micro holes. Therefore, the jet printing density is improved, and characters are formed quickly.

Optionally, the length of the communicating groove is 10mm to 20mm, and the distance between two micro holes corresponding to the same communicating groove is 5mm to 10mm. Like this to make can set up two first piezoelectric crystals that set up along cell body length direction above the intercommunication groove, and guarantee to have sufficient distance between two first piezoelectric crystals, make two first piezoelectric crystals can work independently of each other, avoid a first piezoelectric crystal when warping, cause the influence to the last lid of week side on another first piezoelectric crystal. The distance between the micropores is kept between 5mm and 10mm, and meanwhile, the second piezoelectric crystals arranged on the lower cover piece can be kept at a reasonable distance, so that mutual influence between the two second piezoelectric crystals is avoided.

Specifically, as shown in fig. 12, the first piezoelectric crystal 21 and the second piezoelectric crystal 31 are deformed into the communication groove 10f, and the ink in the groove is pressed and ejected outward. Alternatively, as shown in fig. 13, the first piezoelectric crystals (21, 22) and the second piezoelectric crystals (31, 32) are deformed into the communicating groove 10f, and the ink in the groove is pushed and ejected outward.

Preferably, in the above embodiment, a central axis of the micro hole intersects with a deformation central line of the first piezoelectric crystal. When the first piezoelectric crystal works independently, the ink is extruded when the first piezoelectric crystal deforms, so that the ink can be better transferred to the micropore, and the ink can be injected out more smoothly.

Preferably, in the above-described embodiment, the pressing force of the first piezoelectric crystal against the ink is larger than the pressing force of the second piezoelectric crystal when the electric field is applied. Therefore, the ink is favorably extruded onto the lower cover plate in a whole and is injected out, and the second piezoelectric crystal mainly plays a role in compressing the space of the communicating channel in the jet printing process, so that the ink has a tendency of being injected out of the micropores, and the first piezoelectric crystal can rapidly and massively extrude out of the micropores.

Further, in the above embodiment, the ratio of the young's moduli of the upper cover plate and the lower cover plate is greater than 1, that is, the young's modulus of the upper cover plate is greater than the young's modulus of the lower cover plate, and the lower cover plate is more easily deformed than the lower cover plate.

Specifically, the upper cover plate is made of polyimide, polyamide or polyether ether ketone, and the lower cover plate is made of polytetrafluoroethylene with a smaller young's modulus.

Further, in the above embodiment, a thickness ratio of the upper cover plate to the lower cover plate is greater than 1. Specifically, the thickness of the upper cover plate is 70-150 micrometers, and the thickness of the lower cover plate is 50-70 micrometers. The deformation of the lower cover plate can be completed before the deformation of the upper cover plate, part of the ink forms suspension liquid drops at the micropores of the lower cover plate, and when the lower cover plate deforms, the suspension liquid drops are enlarged and sprayed out of the micropores, so that the ink can be injected out in a large amount in a short time.

In addition, as shown in fig. 8, in the above embodiment, the sum of the thicknesses of the lower cover plate 30 and the second piezoelectric crystal 32 is smaller than the depth of the planar groove 10 g. In addition to embedding the lower cover 30 and the second piezoelectric crystal 32 in the planar groove 10g, a metal guard (not shown) is additionally provided on the outside of the substrate 10, thereby providing a good protection effect for the lower cover 30 and the second piezoelectric crystal 32.

In the above embodiment, as shown in fig. 1, the inkjet head further includes a base 40, and a first surface of the base 40 is bonded to the substrate 10. As shown in fig. 5, the base 40 has an avoidance groove 40c that avoids the upper cover plate 20, and an ink inlet chamber 40a and an ink return chamber 40b that communicate with the first fluid groove 10b and the second fluid groove 10 c. When the number of the communication grooves 10f is large, the lengths of the first fluid grooves 10b and the second fluid grooves 10c are long, which is disadvantageous in communication with an external pipe. By arranging the base 40, arranging the ink inlet cavity 40a and the ink return cavity 40b at two ends of the first surface of the base 40, and arranging the ink inlet groove 10a and the ink return groove 10d which are arranged along the X axis at two ends of the first surface of the substrate 10 respectively, the ink inlet groove 10a is communicated with the first fluid groove 10b, and the ink return groove 10d is communicated with the second fluid groove 10 c; after the base 40 and the substrate 10 are joined in a sealing manner, the ink inlet chamber 40a communicates with the ink inlet tank 10a, and the ink return chamber 40b communicates with the ink return tank 10 d. Thus, an ink inlet tube 41 communicating with the ink inlet chamber 40a and an ink return tube 42 communicating with the ink return chamber 40b may be provided directly on the base 40 for the printhead to communicate with the ink supply circuit. At this time, the flow of ink in the print head is as shown in fig. 7.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a be applied to high-speed jet printing head of inner loop of PCB or FPC character jet printing equipment which characterized in that includes:

the upper cover plate covers the planar groove, micropores communicated with the communicating grooves in a one-to-one correspondence mode are formed in the upper cover plate, and second piezoelectric crystals corresponding to the communicating grooves in a one-to-one correspondence mode are arranged on the surface, away from the planar groove, of the upper cover plate;

the first and second piezoelectric crystals are configured to: the first piezoelectric crystal and the second piezoelectric crystal deform in opposite ways when an electric field is applied.

2. The internal circulation high-speed jet printing head applied to the PCB or FPC character jet printing equipment as claimed in claim 1, wherein there are two micro holes corresponding to each of the communication grooves, there are two first piezoelectric crystals corresponding to each of the communication grooves, and the first piezoelectric crystals correspond to the micro holes.

3. The internal circulation high-speed jet printing head applied to the PCB or FPC character jet printing equipment as claimed in claim 2, wherein the length of the communication groove is 10mm to 20mm, and the distance between two micro holes corresponding to the same communication groove is 5mm to 10mm.

4. The internal circulation high-speed jet printing head applied to the character jet printing equipment of the PCB or FPC as claimed in claim 2, wherein a central axis of the micro-hole intersects a deformed central line of the first piezoelectric crystal.

5. The internal circulation high-speed inkjet head applied to a PCB or FPC character printing apparatus as claimed in any one of claims 1 to 3, wherein the pressing force of the first piezoelectric crystal to the ink is larger than the pressing force of the second piezoelectric crystal when an electric field is applied.

6. The internal circulation high-speed jet printing head applied to the PCB or FPC character jet printing equipment of claim 5, wherein the ratio of Young's modulus of the upper cover plate to that of the lower cover plate is more than 1.

7. The internal circulation high-speed jet printing head applied to a PCB or FPC character jet printing device as claimed in claim 6, wherein the upper cover plate is made of any one of polyimide, polyamide or polyetheretherketone, and the lower cover plate is made of polytetrafluoroethylene.

8. The internal circulation high-speed jet printing head applied to the PCB or FPC character jet printing equipment as claimed in claim 6, wherein the thickness of the upper cover plate is 70-150 microns, and the thickness of the lower cover plate is 50-70 microns.

9. The internal circulation high-speed jet printing head applied to a PCB or FPC character jet printing device of claim 1, wherein the sum of the thicknesses of the lower cover plate and the second piezoelectric crystal is less than the depth of the planar slot.

10. The internal circulation high-speed jet printing head applied to the character printing equipment of the PCB or FPC as recited in claim 1, further comprising a base, wherein the first surface of the base is jointed on the base and is provided with an avoiding groove for avoiding the upper cover plate and an ink inlet cavity and an ink return cavity which are communicated with the first fluid groove and the second fluid groove.