CN114029198B

CN114029198B - Dispensing device and dispensing method thereof

Info

Publication number: CN114029198B
Application number: CN202111303285.2A
Authority: CN
Inventors: 徐银森; 林毛毛; 谢杏梅
Original assignee: Sichuan Suining Lipuxin Microelectronic Co ltd
Current assignee: Sichuan Suining Lipuxin Microelectronic Co ltd
Priority date: 2021-11-04
Filing date: 2021-11-04
Publication date: 2023-02-03
Anticipated expiration: 2041-11-04
Also published as: CN114029198A

Abstract

The invention provides a glue dispensing device and a glue dispensing method thereof. This adhesive deposite device includes: the valve comprises a fluid cavity, a first channel, a second channel, a valve core and a first baffle; the fluid cavity, the first channel and the second channel are sequentially arranged from top to bottom; the valve core is positioned in the fluid cavity and can reciprocate up and down in the fluid cavity and the first channel; the first baffle is arranged in the side wall of the dispensing device and used for isolating the first channel and the second channel.

Description

Dispensing device and dispensing method thereof

Technical Field

The invention relates to the field of semiconductor device packaging, in particular to a glue dispensing device and a glue dispensing method thereof in semiconductor packaging.

Background

In microelectronic packaging, fluid dispensing techniques are introduced for mounting the chip on the substrate, for packaging and for applying the chip. The dispensing technology is divided into contact dispensing and non-contact dispensing. Wherein, the Z of nozzle equipment need be fixed a position to the contact point is glued, otherwise glue the problem such as the point size is inhomogeneous easily to appear. In other words, the Z-direction displacement causes the dispensing quality to be affected by the distance between the nozzle and the substrate, and the dispensing consistency is poor.

Therefore, the traditional contact type dispensing has the problems of limited fluid viscosity range, low spraying speed, inaccurate positioning, poor consistency of dispensing points, poor adaptability and the like.

Non-contact dispensing is a dispensing technique that is currently widely used following contact dispensing. By applying a larger pressure to the fluid instantaneously, the fluid is ejected from the nozzle at an instantaneous speed, and is deposited on a position corresponding to the dispensing required position.

Non-contact dispensing can be divided into mechanical dispensing and piezoelectric dispensing. The mechanical dispensing is different from the piezoelectric dispensing, and can be applied to fluid with medium and low viscosity and fluid with higher viscosity. Specifically, the mechanical dispensing device moves downwards through the valve core to apply pressure to the fluid, so that the fluid in the nozzle is ejected. After the fluid is sprayed out, the valve core moves upwards, and the fluid moves downwards under the double action of external pressure and gravity to fill a cavity formed after the fluid is sprayed out.

However, in the above process, at the moment that the valve core moves upwards, the valve core drives part of the fluid contacting with the valve core to move upwards, and the fluid has viscosity, especially high-viscosity fluid, so that the fluid which is not ejected from the nozzle and the channel at the lower part of the valve core is acted by an upward force, and meanwhile, because the nozzle is provided with an opening, air moves upwards through the opening of the nozzle. Due to the reasons, on one hand, more hollow parts are formed in the nozzle, so that the fluid is insufficient when the nozzle is sprayed next time, the size of the glue body for dispensing next time is influenced, and the bonding is not firm; on the other hand, air may enter the main cavity carrying the fluid to form large bubbles, which affects the control of the fluid and also causes the size of the colloid to be uneven.

How to solve the above problems becomes a problem which needs to be solved urgently.

Disclosure of Invention

The invention provides a glue dispensing device and a glue dispensing method thereof, wherein the glue dispensing device has high glue dispensing accuracy, the size of the glue dispensing point conforms to the required size, and the positioning of liquid drops is accurate; meanwhile, the consistency of the glue dots is good, namely, the diameter and the quality error of a series of sprayed glue dots are small, the size of the glue dots is proper, the glue dots are uniform and round, and the bonding is firm; in addition, the baffle and the valve core are in motion fit through proper control, so that air can be prevented from entering each channel of the fluid, and the problem of nonuniform colloid introduced by the air is avoided.

The glue dispensing device of the invention comprises: the valve comprises a fluid cavity, a first channel, a second channel, a valve core and a first baffle; the fluid cavity, the first channel and the second channel are sequentially arranged from top to bottom; the valve core is positioned in the fluid cavity and can reciprocate up and down in the fluid cavity and the first channel; the first baffle is arranged in the side wall of the glue dispensing device and used for isolating the first channel and the second channel. The first channel and the second channel are separated, so that air can be prevented from being introduced, and the consistency of glue points is ensured.

Optionally, the cross-sectional area of the spool is greater than the cross-sectional area of the second passage. The normal glue spraying is ensured.

Optionally, the second channel lower portion is tapered.

Optionally, the first baffle is disposed in a side wall corresponding to the first channel, or disposed in a side wall corresponding to the second channel.

Optionally, a pressurizing device is further included; the pressurizing device pressurizes fluid to accelerate the fluid to flow from top to bottom in the dispensing device.

Optionally, a first driving device is further included; the first driving device drives the valve core to reciprocate up and down in the fluid cavity and the first channel.

Optionally, the method further comprises: the first sensing device is used for sensing the position of the valve core; and the second sensing device is used for sensing the position of the first baffle.

Optionally, the method further comprises: a second baffle; the second baffle is positioned at the opening at the lower part of the second channel so as to close and open the opening at the lower part of the second channel.

The invention also provides a dispensing method of the dispensing device, which comprises the following steps:

driving the valve plug to move downwards;

sensing that the valve core is in place and then outputting a first trigger signal;

in response to the first trigger signal, the first baffle performs a first action;

sensing that the first baffle is in place and outputting a second trigger signal;

in response to the second trigger signal, the valve core moves upwards;

and after the valve core moves upwards for a certain time or distance, the first baffle plate executes a second action.

In addition, the invention also provides another dispensing method of the dispensing device, which comprises the following steps:

the valve plug is driven to move downwards;

responding to the first trigger signal, the first baffle performs a first action, and the second baffle performs a third action;

in response to the second trigger signal, the valve core moves upwards;

after the valve core moves upwards for a certain time or distance, the first baffle plate executes a second action;

and when the valve core stops moving upwards, the second baffle performs a fourth action.

The invention adopting the technical scheme has the advantages that:

the accuracy of the glue dots is high, the size of the glue dots meets the required size, and the positioning of the liquid drops is accurate.

The consistency of the glue dots is good, the diameter and the quality error of a series of sprayed glue dots are small, the size of the glue dots is proper, and the glue dots are uniform and round.

Through appropriate control, the baffle and the valve core are in motion fit, so that air can be prevented from entering each channel of the fluid, and the problem of nonuniform colloid introduced by the air is avoided.

When the valve core moves upwards, the fluid in the lower channel is driven to move upwards to cause backflow, and the influence on the quality of next dispensing is avoided.

Drawings

In order to illustrate the technical solution of the present invention more clearly, the drawings of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description relate only to some embodiments of the present invention and are not limitative thereof.

Fig. 1 is a cross-sectional view of a dispensing apparatus according to an embodiment of the present invention;

fig. 2 is a cross-sectional view of a dispensing apparatus according to another embodiment of the present invention;

fig. 3 is a flowchart of a dispensing method of a dispensing apparatus according to an embodiment of the present invention;

fig. 4 is a flowchart illustrating a dispensing method of a dispensing apparatus according to another embodiment of the invention;

in the figure: 1-fluid cavity, 2-first channel, 3-second channel, 4-nozzle, 5-valve core, 6-first baffle, 7-side wall, 8-first driving device, 9-first sensing device, 10-second sensing device and 11-second baffle.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. It should be apparent that the described embodiments are only some of the embodiments of the present invention, and not all of them. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without any inventive step, are within the scope of protection of the invention.

As shown in fig. 1, a dispensing device provided in an embodiment of the present invention includes a fluid chamber 1, a first channel 2, a second channel 3, a valve core 5, a first baffle 6, and a sidewall 7. Wherein, fluid cavity 1, first passageway 2, second passageway 3 set up from last to down in proper order.

After entering the fluid chamber 1, the fluid can flow along the fluid chamber 1, the first channel 2 and the second channel 3 under the action of the external pressure and gravity to fill the whole fluid channel. The ambient pressure may be obtained by a pressurizing device (not shown in the figures). The pressurizing device pressurizes the fluid to accelerate the fluid to flow from top to bottom in the dispensing device.

The lower part of the second channel 3 is provided with an opening, and fluid can be sprayed out through the opening under the action of pressure so as to carry out glue dispensing. Thus, the lower part of the second channel 3 can be regarded as a nozzle 4, and the nozzle 4 can be selected to be needle-shaped (cylindrical) or conical. A conical nozzle is selected in the embodiment shown in fig. 1. The nozzle 4 is part of the second channel 3, i.e. is integrally formed. Of course, it is also possible to provide the second channel 3 and the nozzle 4 separately, the nozzle 4 being detachably connected to the second channel 3, i.e. the nozzle 4 can be connected to the second channel 3 in some way, for example by screwing. In this case, the opening size of the nozzle 4 may be different, and when the amount of the dispensing is required to be adjusted, the nozzle 4 having a non-opening size may be replaced.

And a valve core 5 which is positioned in the fluid cavity 1 and can reciprocate up and down in the fluid cavity 1 and the first channel 2. When the valve core 5 moves downwards, a large pressure is applied to the fluid, so that the fluid can be sprayed through the nozzle 4 under the action of the pressure. As shown in fig. 1, the valve core 5 extends into the fluid chamber 1 from an upper portion of the fluid chamber 1. The valve element 5 may be driven by a first driving means 8 such that said valve element 5 reciprocates up and down in the fluid chamber 1 and the first channel 2. The first drive means 8 may be an electric motor, hydraulic means or the like. The valve core 5 can be selected as a cylinder, and the bottom is a round surface.

For example, under the action of the first driving device 8, the valve core 5 moves downward at a high speed, and applies a large pressure to the fluid, so that the fluid can only flow along the second channel 3 and is ejected through the opening of the nozzle 4. When the valve core 5 touches a valve seat formed at the bottom of the first channel 2, fluid extrusion (dispensing) is completed), the valve core 5 moves upwards under the action of the first driving device 8, and the fluid flows downwards under the action of external pressure and gravity to fill the lower space. Of course, the valve core 5 (referring to the bottom of the valve core 5) may be located at any suitable position in the fluid chamber 1 and the first passage 2 before moving downwards, and is not necessarily located in the fluid chamber 1. For example, the bottom of the spool 5 may always be located in the first passage 2 at a distance from the bottom of the first passage 2 (the bottom of the first passage 2 and the top of the second passage 3 are formed with valve seats). At this time, the valve body 5 moves downward to the first position of the first passage 2 by the first driving device 8 to complete the injection, and the valve body 5 moves upward to the second position of the first passage 2 by the first driving device 8. The first position may refer to a position where the valve element 5 moves downward and touches a valve seat at the bottom of the first passage 2, or may refer to any position in the first passage 2. In any case, since the valve element 5 protrudes into the fluid chamber 1 from the upper portion of the fluid chamber 1, the movement of the valve element 5 by the first driving means 8 is an up-and-down reciprocating movement in the fluid chamber 1 and the first passage 2.

The cross-sectional area of the valve core 5 is larger than that of the second channel 3, so that the valve core 5 can not enter the second channel 3. It will be appreciated that valve seats are formed at the bottom of the first passage 2 and at the top of the second passage 3. For example, when the valve element 5 is a cylinder, its cross section is a circle. The second channel 3 has a circular channel cross-section. At this time, the cross-sectional area of the spool 5 being larger than the cross-sectional area of the second passage 3 also means that the radius/diameter of the spool 5 is larger than the radius/diameter of the second passage 3. Naturally, the cross-section of the spool 5 and the second channel 3 may be polygonal, oval, etc. in addition to circular, and it must meet certain dimensional requirements to ensure that the spool 5 does not enter the second channel 3, which may be, for example, that the largest diameter of the cross-section of the spool 5 is larger than the largest diameter of the cross-section of the second channel 3. It will be appreciated that the radius of the smallest circle that can accommodate the cross-section of the spool 5 is greater than the radius of the smallest circle that can accommodate the cross-section of the second passage 3. The cross section of the finger valve core 5 and the cross section of the second channel 3 can be completely arranged in a circle.

Since the valve core 5 extends into the fluid chamber 1 from the upper part of the fluid chamber 1 and can move in the first channel 2, it means that the cross-sectional area of the fluid chamber 1 and the first channel 2 is larger than that of the valve core 5 and is also larger than that of the second channel 3. As shown in fig. 1, the sidewall 7 of the dispensing apparatus corresponding to the fluid chamber 1, the first channel 2, and the second channel 3 is stepped, and the bottom surface of the first channel 2 is coplanar with the top surface of the second channel 3. The portion of the inner wall of the second channel 3 extending from the second channel 3 to the bottom of the first channel 2 forms a step (the portion where the first sensing means 9 is located in fig. 1), which can be considered as a valve seat. It will be appreciated that the presence of the valve seat prevents further downward movement of the valve member 5, so that the valve member 5 only reaches the bottom of the first passage 2 and does not extend into the second passage 3 during the downward movement to squeeze fluid. In particular, the lowest point of the downward movement of the valve element 5 can be selected as the upper surface of the valve seat, that is, during dispensing, the valve element 5 moves downward to squeeze the fluid, and when the valve element 5 touches the valve seat, the movement stops, and at this time, the fluid is ejected from the second channel 3 and the nozzle 4 at a high speed. Alternatively, the fluid chamber 1 and the first channel 2 are circular in cross-section, and the cross-sectional area of the fluid chamber 1 is larger than that of the first channel 2.

Illustratively, in the initial state of the dispensing device, the fluid flows along the fluid chamber 1, the first channel 2 and the second channel 3 under the action of the external pressure and the gravity, so as to fill the fluid chamber 1, the first channel 2 and the second channel 3. Since the nozzle 4 has an opening, when dispensing is started, the valve core 5 moves downwards under the action of the first driving device 8 to enter the first channel 2, and is finally stopped at the bottom of the first channel 2 by being blocked by the valve seat (namely, the valve core abuts against a plane where the bottom surface of the first channel 2 and the top surface of the second channel 3 are coplanar), so that the fluid at the lower part can be extruded, and the fluid is pressurized and then is ejected from the opening of the nozzle 4.

Optionally, the dispensing device of the present invention includes a first baffle 6 disposed in a sidewall 7 of the dispensing device, which functions to isolate the first channel 2 from the second channel 3 and to block the flow of air or fluid between the first channel 2 and the second channel 3 at a proper time.

The first baffle 6 extends out of the side wall 7 in a working state to isolate the first channel 2 from the second channel 3. As shown in fig. 1, it may be provided in particular in a corresponding side wall 7 of the first channel 2, in particular in a corresponding side wall 7 at the bottom or lower part of the first channel 2. In particular, it may be arranged in the side wall 7 corresponding to the plane in which the bottom surface of the first channel 2 and the top surface of the second channel 3 are coplanar, that is to say, the first baffle 6 is arranged in the plane in which the bottom surface of the first channel 2 and the top surface of the second channel 3 lie, that is to say, the plane in which the upper surface of the valve seat lies. Of course, it may also be located in the side wall 7 corresponding to the second channel 3 (in particular in the second channel 3 close to the above-mentioned plane, i.e. in the upper part of the second channel 3), or in the side wall corresponding to the first channel 2. Regardless of the arrangement, the lowest point of the valve core 5 needs to be considered, and the first baffle 6 is prevented from being blocked by the valve core 5 when the valve core 5 descends to the lowest point. For example, when the lowest point of the stroke of the valve element 5 does not reach the upper surface of the valve seat (does not abut), the lowest point of the stroke of the valve element 5 can be selectively arranged in the side wall 7 corresponding to the channel below the lowest point of the stroke of the valve element 5, for example, in the side wall 7 corresponding to the bottom or lower part of the first channel 2 and in the side wall 7 corresponding to the second channel 3; when the lowest point is the upper surface of the valve seat, the first baffle 6 needs to be disposed slightly downward, for example, in the corresponding side wall 7 of the second passage 3, so as to avoid the situation that the protrusion is obstructed by the valve core 5.

It will be appreciated that regardless of the position of the first baffle 6, when it is extended, the fluid or gas may be blocked by the first baffle 6, and the upper fluid cannot continue to flow downwardly through the first baffle 6, particularly to the second passage 3 below the first baffle 6, nor can the lower fluid of the first baffle 6 move upwardly into the passage above the first baffle 6, such as the first passage 2. Based on this, the first baffle 6 may isolate the first and

second passages

2, 3 to some extent.

Of course, the extension and retraction of the first shutter 6 into and out of the side wall 7 is controlled by a drive mechanism, which is also located in the side wall 7 (not shown).

Since the first shutter 6 is disposed in the sidewall 7, this requires that the portion of the sidewall 7 of the dispensing apparatus must have a certain thickness to ensure that the portion of the sidewall 7 can accommodate the first shutter 6. The first baffle 6 also has to be dimensioned to meet certain requirements, for example, when the first baffle 6 is extended, the first channel 2 and the second channel 3 can be completely isolated, and the fluid can be blocked from flowing between the first channel 2 and the second channel 3. In a possible way, the side walls 7 correspond to the fluid chamber 1, the first channel 2 and a part of the second channel 3. As shown in fig. 1, i.e. the second channel 3 is not completely surrounded by the side wall 7. The lowest point of the side wall 7 is higher than the lowest point of the second channel 3. Of course, it is also possible to have the side wall 7 only enclosing the fluid chamber 1 and/or the first channel 2; it is also possible to have the side walls 7 surrounding the fluid chamber 1, the first channel 2, the second channel 3, i.e. all fluid channels.

It will be appreciated that after fluid has been ejected from the nozzle 4, the valve spool 5 will be moved upwardly by the first drive means 8. Generally, the fluid has high viscosity, and the fluid generates an upward force at the moment when the valve core 5 moves upward to drive the fluid to move upward, so that the fluid has a backflow phenomenon; meanwhile, when the valve core 5 moves upwards, the fluid can be filled downwards under the action of the external pressure and gravity, but the external pressure is not large enough, and the backflow is difficult to avoid. During the above-mentioned backflow, air will also enter the fluid channel from the opening of the nozzle 4, so that the second channel 3 and the nozzle 4 suck air, and more hollow parts exist; during dispensing, part of the air is likely to enter the nozzle 4 from the opening of the nozzle 4, and the air also flows upward during the reflow. The two parts of air cause insufficient and uneven fluid at the lower part when the next dispensing is carried out, and the dispensing quality is affected. More seriously, air may also enter the first passage 2 and the fluid chamber 1 to form bubbles, and the non-uniformity of dispensing is deepened.

By providing the first shutter 6, which protrudes from the side wall 7 at an appropriate timing (for example, after the dispensing is completed and before the spool 5 moves upward), the first passage 2 and/or the second passage 3 are isolated (closed), and the flow of the fluid between the first passage 2 and the second passage 3 is prevented as much as possible. The upward movement of the valve core 5 can be avoided, and the upward movement of the fluid at the lower part of the valve core 5 can be avoided, so that the sucked air can be avoided from entering the nozzle 4, the second channel 3, the first channel 2 and the fluid cavity 1. Therefore, the fluid channel does not contain air, the diameter and the mass error of the sprayed glue dots are small, the size of the glue dots is proper, and the shape of the glue dots is uniform and round.

Certainly, in order to ensure that the glue amount in the subsequent second channel 3 and nozzle 4 is enough, after the valve core 5 moves upwards for a certain time/distance, the first baffle 6 needs to be retracted to stop isolating the second channel 3 from the first channel 2, so as to ensure that the fluid can flow downwards under the action of the external pressure and gravity to fill the second channel 3 and nozzle 4 in the process of continuing the upward movement of the valve core 5.

The first shutter 6 is designed in the above manner, instead of arranging the position of the first shutter 6 at the outlet of the nozzle 4, for one reason, if the first shutter 6 is arranged at the opening of the nozzle 4, the first shutter 6 will be opened during dispensing, and at this time, even if the opening is closed after dispensing, air cannot be prevented from entering the nozzle 4. More or less air will still enter the nozzle 4 through the nozzle 4 opening and after the dispensing of the glue, the valve element 5 will move upwards, which may also result in air entering the first channel 2 and the fluid chamber 1 via the second channel 3. The air flow to the upper channel is prevented to the maximum extent only by providing the first baffle 6 at the side wall 7 mentioned in the present invention, separating the first channel 2 from the second channel 3.

For example, during dispensing, air may enter the nozzle 4 instantaneously to mix between fluids, and after dispensing, the second channel 3 and the nozzle 4 may not be filled with fluids, and air may also exist at the lower portion of the nozzle 4 near the outlet, and if the first baffle 6 is closed immediately after dispensing is finished, the air will not enter the fluid channels above the first baffle 6, such as the first channel 2 and the fluid chamber 1, under the obstruction of the first baffle 6. The first baffle 6 blocks the first channel 2 and the second channel 3 at the early stage when the valve core 5 moves upwards and starts to move upwards, after a period of time, the upper fluid flows downwards under the action of external pressure, the valve core 5 has no large upward force on the lower fluid, at the moment, the first baffle 6 is driven to return, the first channel 2 and the second channel 3 are not blocked by the first baffle 6, and the upper fluid flows downwards to fill the whole fluid cavity so as to carry out next dispensing. Due to the action of the external pressure, the fluid flows downwards, the valve core 5 can not generate large force to the lower fluid (the fluid which is not sprayed out in the last dispensing) any more, and even if the first baffle 6 is opened, even if a small amount of gas enters the nozzle 4 in the last spraying, the air can not move upwards and enter the fluid channel on the upper part.

In a possible embodiment, in order to realize accurate control, the glue dispensing device is further provided with a first induction device 9 and a second induction device 10; a first sensing device 9 for sensing the position of the spool 5; and a second sensing device 10 for sensing the position of the first barrier 6.

The channel environment is complex due to the presence of fluid in each channel, and the first sensing means 9 may alternatively be a pressure sensor. It may be disposed at a valve seat portion (belonging to the sidewall 7, in fig. 1, a horizontal portion of a step formed by the first passage 2 and the second passage 3) formed at a junction of the first passage 2 and the second passage 3. The downward movement of the spool 5 contacts the first sensing means 9 which, due to the fast speed of movement of the spool 5, will apply a large instantaneous pressure to the pressure sensor, which is a force that the fluid flow cannot cause to the pressure sensor. By detecting the pressure, if the threshold value is exceeded, it is considered that the spool 5 is in position, for example, the spool 5 abuts against the bottom of the first passage 2. The first sensing device 9 may also be selected as a displacement sensor to sense the position change of the valve core 5, and may be disposed on the valve core 5 or disposed at other positions in the channel. Of course, the first sensing device 9 can alternatively be another type of sensor, as long as it can sense the position of the spool 5.

The first sensing device 9 senses the position of the valve core 5, so as to feed back a signal when the valve core 5 reaches the lowest point of the stroke (namely, the dispensing is finished), and based on the feedback signal, the first baffle 6 can be ejected out of the side wall 7 under the action of the driving mechanism to block the first channel 2 and the second channel 3. Due to this, no fluid flows at least from the second channel 3 below the first baffle 6 to the first channel 2 above it.

Optionally, the dispensing device is provided with a second sensing device 10, the function of which is to sense the position of the first shutter 6. Based on this position, the system can determine whether the first baffle 6 has blocked the first and

second passages

2, 3. I.e. there is no possibility of fluid flowing between the upper channel of the first baffle 6 and the lower channel thereof. Specifically, it is impossible to have the fluid flow from the second passage 3 at the lower portion of the first baffle 6 to the first passage 2 at the upper portion thereof, or to have the fluid flow from the passage at the upper portion of the first baffle 6 to the passage at the lower portion thereof, such as the second passage 3. After blocking, the first drive means 8 starts to drive the valve element 5 upwards. By actuating the upward movement of the valve element 5 after ensuring that the first shutter 6 has completely blocked the first and

second channels

2, 3, it is ensured that during the upward movement of the valve element 5 no more air is sucked in from the lower channel, and this air, as well as the small amount of air that is present during the dispensing phase, is not sucked into the channels above the first shutter 6.

The second sensing device 10 may be a pressure sensor or a displacement sensor, which has the same detection principle as the first sensing device 9. When the second sensing device 10 is selected to be a pressure sensor, it may be positioned on the side wall 7; the second sensing means 10, when selected as a displacement sensor, may be provided on the first baffle 6, or on the side wall 7. Of course, the second sensing device 10 can be selected as another type of sensor as long as it can sense the position of the first barrier 6.

In order to ensure the next dispensing quality, the first baffle 6 needs to be popped open immediately after the valve core 5 rises for a certain time or distance, so as to release the blocking state of the first channel 2 and the second channel 3. A timer can be selected for timing, specifically, the timer starts timing at the moment when the system judges that the first baffle 6 blocks the first channel 2 and the second channel 3, and after a specified time is reached, the first baffle 6 is bounced off under the action of the driving mechanism, and the valve core 5 continues to move upwards. When the position (distance) is used to determine the timing of the opening of the first flapper 6, a displacement sensor (first sensing device 9) may be used when the position of the valve body 5 is detected by the displacement sensor. Of course, if the first sensing device 9 is not a displacement sensor, an additional displacement sensor is required to detect the position of the spool 5. When the displacement sensor detects that the valve core 5 rises a specified distance/reaches a specified position, the first driving device 8 drives the first baffle 6 to pop open.

Of course, the invention may also be provided with a second baffle 11 at the opening of the nozzle 4, which second baffle 11 and the first baffle 6 may cooperate to avoid the passage of air to the greatest possible extent. Meanwhile, a driving mechanism (not shown) is provided for the second shutter 11 to drive the second shutter 11 to close or open the opening of the nozzle 4 (the opening at the lower portion of the second passage 3) at an appropriate timing.

An embodiment of the present invention further provides a dispensing method, which may adopt the above-mentioned dispensing apparatus. The method comprises the following steps:

driving the valve plug 5 to move downwards;

sensing that the valve core 5 is in place and then outputting a first trigger signal;

in response to the first trigger signal, the first shutter 6 performs a first action;

sensing that the first baffle 6 is in place and then outputting a second trigger signal;

in response to the second trigger signal, the spool 5 moves upward;

after the valve core 5 moves upwards for a certain time or distance, the first baffle 6 performs a second action.

It will be understood that the valve member 5 is in position, meaning that the valve member 5 has reached a predetermined position, which completes the action of forcing fluid out of the nozzle 4. For example, the valve slide 5 is moved to the lowest point of its pre-designed travel by the first drive means 8. The lowest point may be a position where the valve body 5 abuts against the bottom of the first passage 2 (i.e., a position where it contacts the valve seat), or may be another position that is set in advance. The position of the valve core 5 can be sensed based on the first sensing device 9 so as to judge whether the valve core 5 is in place. After the position is reached, the valve core 5 does not move downwards any more, fluid is not extruded any more, and dispensing is finished. The valve core 5 moves upwards at a proper time, and the fluid fills the whole fluid channel downwards under the action of the external pressure and gravity. As shown in the embodiment of fig. 1, the bottom surface of the first channel 2 is coplanar with the top surface of the second channel 3. Due to the difference in cross-section between the two, the side wall 7 forms a step (i.e., valve seat) at the intersection of the bottom of the first passage 2 and the top of the second passage 3. When the valve core 5 moves downwards, the valve core is blocked by the step and cannot move downwards continuously. When the spool 5 contacts this step, the spool 5 is considered to abut the bottom of the first passage 2.

The first baffle 6 is in place, which means that the first baffle 6 completes the work of isolating the first channel 2 and the second channel 3 after starting to act. The first action can be considered as the action of the driving mechanism, the first shutter 6 is projected and ejected from the side wall 7 to separate the first channel 2 and the second channel 3. When the work of isolating the first channel 2 from the second channel 3 is completed, the fact that after the first baffle 6 is extended, the fluid or gas is blocked by the first baffle 6, the upper fluid cannot flow downwards through the first baffle 6 to the channel below the first baffle 6, such as the second channel 3, and the lower fluid cannot move upwards to enter the channel above the first baffle 6, such as the first channel 2.

The second sensing device 10 senses the position of the first shutter 6, and through the position, whether the first shutter is ejected in place can be judged. For example, when the pressure sensor is selected, the pressure exceeds a threshold value, the first shutter 6 is considered to be in position; with a displacement sensor, the first flap 6 is considered to be in position when the detected displacement exceeds a threshold value. Of course, there are many ways to determine whether the first blocking plate 6 is in place, and the application is not limited herein.

The second action refers to that the driving mechanism drives the first baffle 6 to retract into the side wall, and the first channel 2 and the second channel 3 are separated.

The method described above is exemplified below to make the method of the present application more clear.

The fluid flows through the fluid cavity 1, the first channel 2 and the second channel 3 under the action of the external pressure and gravity to fill the whole fluid channel; during dispensing, the valve core 5 moves downward under the action of the first driving device 8 to apply pressure to the lower fluid, so as to eject the fluid from the opening of the nozzle 4 (i.e. the opening at the lower part of the second channel 3).

The first sensing means 9 detects the position of the downward movement of the spool 5. The detection position may be a real-time detection position, and may also be a real-time position that is determined by real-time position, and may also be a position that is not detected but is directly detected, for example, the pressure sensor is used to detect the touch of the valve element 5, and of course, there are many other types of position sensors, and the application is not limited herein.

When the valve core 5 reaches the target position (namely, is in place), a first trigger signal is generated. The first trigger signal may be generated by: the first sensing device 9 can directly judge whether the valve core 5 reaches the target position according to the detection signal, and if so, generates and outputs a first trigger signal; alternatively, the first sensor device 9 merely sends the detected signal to an additional control device, which determines whether the valve element 5 has reached the target position and generates the first trigger signal when it has reached this target position.

Based on the first trigger signal, the driving mechanism starts to drive the first shutter 6 to perform a first action, for example, to protrude from the side wall 7 to block the communication of the first passage 2 and the second passage 3. Here, the first trigger signal may be directly transmitted to the driving mechanism, or may be transmitted to a controller, and the controller controls the operation of the driving mechanism.

The second sensing means 10 detects the position of the first shutter 6. And generating a second trigger signal after the first baffle 6 is in place. The second trigger signal may be directly sent by the second sensing device 10, in other words, the second sensing device 10 detects the position of the first baffle 6 and determines whether the first baffle 6 is completely ejected or whether the first channel 2 and the second channel 3 are isolated based on the position. Of course, the second sensing device 10 can also send the detected data to the controller, and the controller can make the determination and generate the second trigger signal.

Based on the second trigger signal, the first driving means 8 starts to drive the valve element 5 upward. During movement, the fluid flows downward under the influence of ambient pressure and gravity, filling the lower fluid passage.

When the valve core 5 moves upwards for a certain time/distance, the valve core 5 will not cause the fluid in the lower passage to flow back any more when the valve core 5 continues to move upwards. At this time, in order to normally enter the upper part fluid into each lower part channel, the passage between the first channel 2 and the second channel 3 needs to be opened, and the fluid can flow to the second channel 3 through the first channel 2. Thus, the first shutter 6 now performs a second action, retracting into the side wall 7.

A timer can be adopted for timing, when the second trigger signal is received, the timer starts timing, after the timing is over, the driving mechanism drives the first baffle 6 to retract, and the first channel 2 and the second channel 3 are not in an isolation state any more. The timer may be a separate timer or a timer built in the controller. Or a displacement sensor can be adopted to detect the movement distance of the valve core 5, and after the preset distance is reached, the driving mechanism drives the first baffle 6 to retract.

After the first baffle 6 opens the communication passage between the first channel 2 and the second channel 3, the valve core 5 continues to move upwards, and the fluid continues to flow downwards until the valve core 5 reaches the preset initial position so as to prepare for the next dispensing. It will be appreciated that the valve spool 5 is moving in a downward direction, i.e. from this initial position.

Another method of the present application is directed to a dispensing device with a second shutter 11 at the opening of the nozzle 4 (the lower opening of the second channel 3). This method differs from the above method in that it further comprises the driving of the second shutter 11. The method comprises the following steps:

driving the valve plug 5 to move downwards;

in response to the first trigger signal, the first shutter 6 performs a first action and the second shutter 11 performs a third action;

sensing that the first baffle 6 is in place and outputting a second trigger signal;

in response to the second trigger signal, the spool 5 moves upward;

after the valve core 5 moves upwards for a certain time or distance, the first baffle 6 executes a second action;

the second flapper 11 performs a fourth action when the upward movement of the spool 5 is stopped.

This method is basically the same as the above method, and is not described herein again. The difference is that the first trigger signal also triggers the second flap 11 to perform a third action to close the opening of the nozzle 4 (the lower opening of the second channel 3) and avoid air from the nozzle 4 entering the fluid channel. That is, under the action of the first trigger signal, actually, the first baffle 6 and the second baffle 11 move simultaneously under the action of the respective driving mechanisms, the first baffle 6 blocks the communication between the first channel 2 and the second channel 3, and fluid or air cannot flow back from the lower part of the first baffle 6 to the channel at the upper part of the first baffle; the second shutter 11 closes the opening of the nozzle 4 and air cannot enter the nozzle 4.

When the upward movement of the valve core 5 is stopped, the opening of the nozzle 4 does not need to be closed, and when the upward movement of the valve core 5 is stopped, the second shutter 11 may be driven to perform the fourth action to open the nozzle 4. Therefore, when the valve core 5 stops moving, a feedback signal is required so that the driving mechanism can drive the second shutter 11 to open the opening of the nozzle 4. Of course, the second shutter 11 may be driven to open the nozzle 4 at other times, for example, after the upward movement of the valve element 5 is stopped and before the valve element 5 starts to move downward for the next dispensing. Of course, this requires the system to know not only when the valve spool 5 stops moving upward, but also when the valve spool 5 starts moving downward.

In conclusion, the glue dispensing device and the glue dispensing method provided by the application have the advantages that the accuracy of glue dispensing is high, the size of the glue dispensing meets the required size, and the positioning of liquid drops is accurate. The consistency of the glue dots is good, the diameter and quality error of a series of sprayed glue dots are small, the size of the glue dots is proper, and the glue dots are uniform and round. Through proper control, the baffle and the valve core are in motion fit, so that air can be prevented from entering each channel of the fluid, and the problem of nonuniform colloid introduced by the air is avoided. And the phenomenon that the fluid in the lower channel is driven to move upwards to cause backflow when the valve core moves upwards can be avoided, and the influence on the quality of next dispensing is also avoided.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. An adhesive dispensing device, comprising: the valve comprises a fluid cavity (1), a first channel (2), a second channel (3), a valve core (5) and a first baffle (6); the fluid cavity (1), the first channel (2) and the second channel (3) are sequentially arranged from top to bottom; the valve core (5) is positioned in the fluid cavity (1) and can reciprocate up and down in the fluid cavity (1) and the first channel (2); the first baffle (6) is arranged in a side wall (7) of the dispensing device and used for isolating the first channel (2) and the second channel (3) after dispensing is finished and before the valve core (5) moves upwards;

also comprises a second baffle (11); the second baffle (11) is positioned at the opening at the lower part of the second channel (3) to close and open the opening at the lower part of the second channel (3).

2. Dispensing device according to claim 1, characterized in that the cross-sectional area of the valve element (5) is larger than the cross-sectional area of the second channel (3).

3. Dispensing device according to claim 1, characterized in that the lower part of the second channel (3) is conical.

4. Dispensing device according to claim 1, characterized in that said first shutter (6) is arranged in a side wall (7) corresponding to said first channel (2) or in a side wall (7) corresponding to said second channel (3).

5. The dispensing apparatus of claim 1, further comprising a pressurizing device; the pressurizing device pressurizes fluid to accelerate the fluid to flow from top to bottom in the dispensing device.

6. Dispensing device according to claim 1, characterized in that it further comprises a first drive means (8); the first driving device (8) drives the valve core (5) to reciprocate up and down in the fluid cavity (1) and the first channel (2).

7. The dispensing apparatus of claim 1, further comprising:

a first sensing means (9) for sensing the position of the spool (5);

and the second sensing device (10) is used for sensing the position of the first baffle plate (6).

8. A method of dispensing using the dispensing apparatus of any of claims 1-7, the method comprising: the driving valve plug (5) moves downwards;

sensing that the valve core (5) reaches a preset position, and outputting a first trigger signal after finishing the action of extruding the fluid out of the nozzle (4);

in response to said first trigger signal, the first shutter (6) performs a first action, isolating said first (2) and second (3) channels, the second shutter (11) performs a third action, to close the opening of the nozzle (4);

sensing the first baffle (6) to finish the work of isolating the first channel (2) and the second channel (3) and then outputting a second trigger signal;

in response to the second trigger signal, the valve core (5) moves upwards;

after the valve core (5) moves upwards for a certain time or distance, the first baffle (6) executes a second action to release the isolation of the first channel (2) and the second channel (3);

and when the valve core (5) stops moving upwards, the second baffle (11) executes a fourth action to open the nozzle (4).