CN1250022A - Device for metering and transporting viscous liquid - Google Patents

Abstract

A device for the metered delivery of a viscous liquid has a body (30) with a continuous drill hole (31) in which two pistons (38, 39) are moved back and forth, whereby the distance between the faces is varied. In this way, the pistons transport a specific volume of liquid from a first chamber (42) to a second chamber (43). Device is suitable for mounting onto the writing head (26; 53) of an apparatus for the application of adhesive to a substrate.

Description

The device of metering and transporting viscous liquid

The present invention relates to as the described device of the preorder of claim 1 and 7.

A kind of like this device is for example known from patent specification US4485387.Describe a kind of system in this specification sheets, be used for the thick film screen printing ink is coated to substrate, this system is provided with suction passage and escape route, has the twin-tub with these two passage landscape configuration.By a rotovalve, suction passage alternately is connected on the cylinder, and another cylinder is connected on the escape route simultaneously, and vice versa.The piston that diametrically contraposition ground connects is set in the cylinder of two diametrically contrapositions, and they are moved back and forth consistently by an electrical motor.This valve and piston move synchronously back rotation simultaneously.In this way, in the cylinder of printing ink suction with specified quantitative, and simultaneously at the printing ink of another cylinder place discharge scheduled volume, the stroke of piston can be regulated, and therefore the printer's ink water yield of suction and discharge can be regulated as required.In order to guarantee the zero defect operation of this device, this device has sizable size, and thereby weight very big.Therefore this device is connected on the pencil by long tube, pencil can be crossed substrate and move.

In order to be that IC is electrically connected to integrated circuit, on sheet metal, go out with framework (so-called lead frame) bonded assembly connecting pin.Utilize so-called die attach adhesives coating integrated circuit subsequently, then it is bonded on the connecting pin.For this reason, the epoxyn that the specific dimensions integrated circuit is used is coated on the corresponding lead frame, and this preferably finishes with said apparatus.Have short work life because epoxyn or resin depend on its composition, reside in the gauging device, therefore must clean regularly it so its residual life lags behind.For this reason, this device must be dismantled and with the cleaning cream that is similar to potash soap (inhibiter) rinsing.Thereafter, must ressemble this device carefully, this needs certain skill, especially to sealing member.Particularly, the stuffing box chamber that exists in this device screws with torque wrench.The long tube that leads to pencil also must clean, and needs in case of necessity to replace.Much less, these devices are very complicated, and are therefore very expensive, especially for piston actuated.

For top and other reason, the objective of the invention is to improve by this way the device of the above-mentioned type, even also it is in light weight, cleaning can be more simplified in easier and manufacturing more cheaply.

This purpose is to utilize the device of the characteristics with claim 1 or claim 7 to reach.

Use device of the present invention, can have especially little structure, thus they in addition can the movable pencil of the device of adhesive applicating to the substrate be assembled together with a kind of being used for.

Can obtain other advantage of the present invention by the Patent right requirement of subordinate with by following description, be that the present invention is described on the basis in more detail with the embodiment that represents in the scheme drawing wherein.In the accompanying drawing:

Fig. 1 is a kind of planar view of gauging device;

Fig. 2 is the lateral plan of this gauging device;

Fig. 3 is the planar view with this gauging device of a valve expansion;

Fig. 4 is the lateral plan that enlarges and be installed in this gauging device on the pencil with this valve;

Fig. 5 is another gauging device;

Fig. 6 is that this another gauging device is in different phase of operation; And

Fig. 7 is a kind of being used for the device of adhesive applicating on substrate.

Fig. 1 and 2 represents a kind of planar view or lateral plan that is used for the gauging device of metering and transporting viscous liquid, and this device comprises sliding part and cover plate 3 that a main body 1, can be rotated around pivot center A.A cavity is arranged between main body 1 and cover plate 3, therefore when inserting sliding part 2, form a circular channel 4.At end regions 5 and 6 places, passage 4 is connected to through feeding channel 7 and 8 and is connected on the ozzle 9.Near end regions 5 places a breach 10 is arranged in passage 4, it is used for being full of passage 4 with liquid initial.Sliding part has a cam 2a who protrudes in the passage 4, utilizes this cam to promote liquid by passage 4.

Rotary sliding part 2 utilizes electrical motor 11 to rotate, and wherein connects a reducing gearbox 12 between electrical motor 11 and sliding part 2.Main body 1 and cover plate 3 can link together with taking apart, for example utilize screw 13 or utilize engaging member to connect.Main body 1 has a boring 14, can utilize light pressure that sliding part 2 is inserted wherein.There is a recess 15 on the surface towards cover plate 3 of dish 2, and the area that cover plate 3 is contacted with sliding part 2 can maintain slightly, and the size of this area only is that fully sealing is required.Therefore the edge of sliding part 2 forms sealing flange.In this way, can guarantee to seal effectively, also promptly seal effectively at cam 2a place along the edge of concentric stroking moving part 2 and certainly at predetermined position.Other recess 16 on the sliding part 2 has such effect, also is that the area of contact of sliding part 2 and main body 1 is also quite little.The size of sliding part 2 is selected like this, makes under the confined state of gauging device, and sliding part 2 is sandwiched between main body 1 and the cover plate 3, still, preferably still can rotate with hand.Because the circle of passage 4 (Fig. 1), gauging device has the structure of a compactness, this fully seals because of the force fit of sliding part 2 on the one hand, liquid can not be flowed into, and make friction between sliding part 2 and main body 1 and the cover plate 3 because groove 15 and 16 and enough low on the other hand, so sliding part 2 can rotate by a specific angle φ with essential precision all the time.Much less, groove 15 and 16 also can be applied to cover plate 3 or main body 1.In order to purify gauging device 1, remove cover plate 3, take out sliding part 2.Gear case 12 does not contact the liquid of preparing application with electrical motor 11.

Main body 1 and cover plate 3 for example are made of a steel, and sliding part 2 is made of plastic, therefore form desirable sliding properties between sliding part 2 and main body 1 and cover plate 3.It is contemplated that also all these parts can be made of plastic as injection molded.

In Fig. 3 and Fig. 4,17 combinations of gauging device and valve make the gauging device can be along two rotation direction continuous handlings of sliding part 2.Gauging device and valve 17 are preferably made one as shown in the figure, but also can separate.It for example is a rotovalve 17 that valve 17 is designed to, and it has two to rotate 90 ° suction passages 20 along the opposed interface channel 18 of diameter and 19 and one, the latter have one with its along the opposed transfer passage 21 of diameter.Feeding channel 7 and 8 directly extends in interface channel 18 or 19, and can keep extremely short.Passage 18 to 21 all opening wherein rotates sliding part 23 and can move forward and backward between the two positions basically in slotted eye 22.Rotate sliding part 23 and driven by electrical motor 24, reducing gearbox 25 is connected electrical motor 24 and rotates between the sliding part 23.In the primary importance of graphic rotation sliding part 23, left interface channel 18 is connected on the suction passage 20 and right interface channel 19 is connected on the transfer passage 21.Rotate 90 ° on the second place that dots the time when rotating sliding part 23, operational circumstances is reversing just.In operation, suction passage 20 is connected in the container that comprises viscous liquid.The gauging device supporting with rotating valve 17 preferably is installed on the transportable pencil 26, makes transfer passage 21 directly form one thus and writes nozzle.

When initially being full of gauging device, the rotation sliding part 23 of rotovalve 17 is arranged in the primary importance that Fig. 3 represents, and the rotatable sliding part 2 of gauging device is settled in the position shown in Figure 1.Viscous liquid (not shown herein) is pressed in the circular channel 4 by left interface channel 18 under the pressure of about 5 crust now as epoxyn, and discharges transfer passage 21 again by interface channel 19.Because sliding part 2 is arranged in breach 10, the liquid that pushes by feeding channel 7 under pressure can easily flow and flow channel 4 around sliding part 2.The air that exists in the transfer passage 7 was pushed before liquid thus, finally by transfer passage 21 output gauging devices 1.Be used to make the special drilling (being called " bloodletting " by the expert) of gauging device ventilation not need in the prior art.In this way, bubble is eliminated automatically in the pump, does not also promptly need external control.

Then, rotate rotary sliding part 2 along clockwise direction, occupy a position with the E mark up to cam 2a.Gauging device is full of viscous liquid now, and prepares to distribute the liquid on the not shown substrate.For each assign action, sliding part 2 rotates by a predetermined angular φ, and the gluing dosage of Pai Chuing is proportional to angle φ thus.After predetermined assign action several times, the cam 2a of sliding part 2 is arranged in the position F that dots.In this case, the rotation sliding part 23 of rotovalve 17 moves to its second place now, and the reversing of the rotation direction of sliding part 2.Therefore, after n added once assign action, sliding part 2 was got back to position E.For application of liquid, sliding part 2 moves back and forth the n step respectively between position E and F, and the position of the rotation sliding part 23 of rotovalve 17 changes in position E and F respectively thus.When n=1, the liquid of maximum is coated on the substrate.

If the gauging device supporting with rotovalve 17 is installed on the movable pencil 26, determine the sliding part 2 of amount of liquid to be applied so and the distance of writing between the nozzle can be very short to this structure.This amount of liquid that makes each assign action discharge has high playback accuracy.If gauging device is not installed on this pencil as common in the prior art, and at transfer passage 21 and write between the nozzle settle one be generally 300mm than long tube, so, because the characteristic of liquid, the pipe of full of liquid carries out work as " small throughput " and control amount of liquid to be discharged is very difficult.

For the Technology professional, much less, it is contemplated that also that above-mentioned gauging device not only can adopt circular channel 4 and rotating sliding part 2, and can adopt rectilinearity passage and the sliding part that moves forward and backward of portion within it.

Fig. 5 represents to be used to measure another gauging device of carrying liquid, this gauging device has one first main body 30 and two other main bodys 34 and 35, first main body 30 with three be arranged in parallel continuously and the boring 31,32,33 that level is advanced, other main body 34 with 35 each be connected the piston 38 or 39 of a guide rod 36 or 37 and one operation in parallel.Main body 30,34 and 35 is preferably made of plastic.By first guide rods 36, by second guide rod 37, and hole in 31 by two pistons 38 and 39 in the boring 33 in the boring 32, main body 34 is positioned at a side of boring 31 thus, and main body 35 is positioned at the opposite side of boring 31.The 31 at both ends places that hole enlarge, and to accept a sealing element 40 and a bearing sub-assembly 41, each is corresponding to corresponding piston 38 or 39.The center of boring 31 connects two chambers 42 and 43 that are installed in the main body 30, and first chamber 42 in operation thus is connected on the container that comprises liquid, and second chamber is connected to be write on the nozzle 44.For this reason, for example, connect the ozzle 45 that pipe uses or write nozzle 44 and directly insert in the corresponding chamber 43 or 42 respectively.

Main body 34 and 35 with they guide rod 36 and 37 and piston 38 and 39 can move along boring 31,32 and 33 direction.In fact guide rod 36 and 37 supports two pistons 38 and 39.Main body 34 and 35 driving are to utilize two face cams 46 and 47 that are arranged on the turning cylinder to finish, and by using direct motor drive altogether.For this reason, main body 34 and 35 has the cam 48 of a contiguous corresponding face cam 46 or 47.Two main bodys 34 and 35 utilize one in advance the spring 49 of tension is connected, makes cam 48 and face cam 46 or 47 accordingly remain and contact, and piston 38 and 39 mobile followed the face cam 46 of alloting or 47 staggered carrying out.Independent 360 ° of rotation of electrical motor or face cam 46 and 47 are directed at once moving forward and backward separately of piston 38 and 39.

Fig. 6 A-6F schematically illustrates during face cam 46 and 47 once rotates separately the relative position of piston 38 in six different angles positions and 39.In when beginning, piston 38 and 39 face are positioned at first chamber 42, form a small gap (Fig. 6 A) thus between two faces of piston 38 and 39.Therefore at first, only piston 38 moves, and the slit between two pistons 38 and 39 enlarges.The slit of this expansion is full of liquid (Fig. 6 B) immediately.Afterwards, two pistons 38 and 39 moved to second chamber 43 from first chamber 42, and the width in slit keeps constant (Fig. 6 C) thus.In this way, a predetermined amount of liquid is transported to the chamber 43 from chamber 42.Thereafter, piston 39 keeps static (Fig. 6 D), and piston 38 back moves, and the face between two pistons 38 and 39 reaches original little width (Fig. 6 E) once more.During this phase place, the amount of liquid in the slit between piston 38 and 39 is pressed in the chamber 43.Subsequently, two pistons 38 and 39 back move, and make the slit between the two-piston face keep little width (Fig. 6 F) thus, and after electrical motor complete rotation one circle, the two-piston face is arranged in initial position (Fig. 6 A) once more.Therefore, during a crank motion of piston 38 and 39, the distance between its surface changes, wherein in the distance during moving of advancing greater than the distance that retreats during moving, make the liquid of a predetermined be transported to second chamber 43 from first chamber 42.

Wei Sipeier (Vespel[polyimide]) is a kind of duroplasts that can process as brass, and these plastics are the suitable materials as main body 30.Piston 38,39 and guide rod 36, the 37 preferably jumper bar under the shearing of routine are made, as be used as the sort of jumper bar of push-off pin in injection moulding technology.Jumper bar under this kind shearing has the surface of dead smooth.The end of piston 38,39 is circular.Sealing member 40 (Fig. 5) is used than flexible plastic such as polytetrafluoroethylene and is made.For short distance, the internal diameter of selection sealing member 40 is slightly smaller than the internal diameter of piston 38,39, makes sealing member 40 closely around corresponding piston 38 or 39, still, does not depart from the scope of plastic deformation.Therefore, in the short range on the side of chamber 42 or 43 that is positioned at sealing member 40, produce sealing.Bearing part 41 is to use than sealing member 40 harder plastics to make on the other hand, therefore, as long as the supporting of piston 38,39 is not produced by guide rod 36 or 37, not influenced by sealing member 40 with regard to influenced by bearing part 41.

Because spring 49 is strained between two main bodys 34 and 35, so its expansion is only owing to the difference amount between slit minimum width and the maximum width changes.The constraint of main body 34 and 35 medi-springs 49 results from as close as possible guide rod 36,37 places, therefore, acts on torque on respective bore 32 or 33 because spring 49 and as far as possible little from guide rod 36 and 37.Utilize additional spring, can eliminate these torques fully.

Boring 31 diameter, and the minimum width in slit and the difference between the maximum width between the face of piston 38 and 39 are according to liquid minimum volume V to be carried _MinDetermine size.Utilize the coated liquid volume of independent primary distribution action to finish the n circle and rotate and be increased to liquid volume V owing to electrical motor _MinN doubly.This device is equally applicable to the point-like coating of liquid part and writing of liquid wire and figure, writes axis during the point-like coating and keeps static, writes axis when wire and graphical handwriting and moves along preset lines at a predetermined velocity.The rotation direction and the speed of electrical motor cooperatively interact, and are write mobile control, make predetermined amount of liquid be coated on the substrate in the pre-position according to given liquid figure.

This device can have a special advantage, can be without valve when being exactly its work.Also can reverse operation, this moment, liquid was transported to first chamber 42 from second chamber 43.Slit between two pistons 38 and 39 the face keeps minimum finite width can guarantee that operation do not have wearing and tearing.

Two kinds of gauging devices can be built very compactly, therefore they can be directly installed on half adhesive applicating on the pencil of the equipment of using on the substrate, this equipment for example obtains describing in european patent application book EP901155, and this equipment clearly is incorporated herein by reference.Fig. 7 is corresponding to the Fig. 1 among the EP901155.According to the explanation of EP901155, liquid supplies to dispensing head 50 by pipe 51, wherein settles a figure who does not illustrate at the other end of pipe 51, utilizes the amount of this pump metering glue mucus to be applied.A kind of being directly installed in the gauging device of the present invention can be replaced dispensing head 50 on the suspension bracket 52 now, make the pump of the gluing liquid measure of metering be placed on the pencil 53 also mobile with it.In this way, between the tip of the gauging device of carrying out pumping function and pencil 44, form shorter distance, its advantage is, even have very high writing speed and short writing the cycle, write and move and the cooperatively interacting of the action of pump, promptly obtain simplifying as the function of time and with reference to the control of rotation direction of writing mobile electrical motor and speed.

Two kinds of gauging devices are equally applicable to apply the adhesion agent and the more low-viscosity liquid of high viscosity, bead topping material or underfill material that the latter for example uses as flip chip.

Claims (9)

1. A device for metering and delivering viscous liquids, comprising a suction passage (20) through which the liquid is supplied and a delivery passage (21) through which the liquid is delivered, a valve operated in two positions ( 17) and a separate channel (4), the two end regions (5, 6) of this separate channel can be connected alternately to the suction channel (20) or the delivery channel (21) by means of a valve (17), wherein, The cam (2a) of the slider (2) can reciprocate between two positions (E, F) in the channel (4), characterized in that the channel (4) has a notch (10). 2. Device according to claim 1, characterized in that the channel (4) has a circular shape and the slide (2) is rotatable on the axis of rotation (A). 3. The device according to claim 1 or 2, characterized in that the device has a main body (1) and a cover plate (3), and the sliding part (2) can be inserted into the borehole (14) of the main body (1) . 4. The device according to claim 3, characterized in that the sliding part (2) or the main body (1) or the cover plate (3) has at least one recess (15, 16) to reduce the The area where the body (1) or slide (2) and cover (3) come into contact. 5. Device according to one of claims 1 to 5, characterized in that the slide (2) is made of plastic. 6. Device according to one of claims 3 to 5, characterized in that the body (1), the slide (2) and the cover (3) are made of plastic. 7. A device for metering and conveying viscous liquids, comprising a main body (30) having a first chamber (42) through which liquid is supplied and a second chamber (43) through which liquid is conveyed, It is characterized in that the two chambers (42, 43) are connected by a bore (31), and the two pistons (38, 39) can reciprocate in the bore (31), whereby during the reciprocating movement , the distance between the faces of the two pistons (38, 39) facing each other changes. 8. The device according to claim 7, characterized in that each of the two pistons (38, 39) is supported in the borehole (31) by a bearing (41) and is opposed to the piston by a seal (40). The borehole (31) is sealed, wherein the bearing element (41) is made of a harder material than the sealing element (40). 9. A device for applying a liquid to a substrate with a movable writing head (26; 53), characterized in that a device for metering and delivering the liquid is mounted on the writing head (26; 53).

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