Syringe housing for enhancing stability of fluid dispensing

Abstract

An injector housing has a space. The space is sized to receive an injector containing a fluid to be dispensed. The injector is insertable into the injector housing through an opening in a first end of the injector housing, and a nozzle configured to engage a dispensing tip of the injector is located at a second end of the injector housing opposite the first end. An injector adapter is removably coupled to the injector housing for retaining the injector after insertion into the injector housing, the injector adapter including a pneumatic connector connectable to a gas source for introducing gas into an air chamber enclosed within the injector housing and the injector. The gas is operable in use to exert a force within the injector to drive dispensing of the fluid through the nozzle.

Description

Technical Field

[0001] This invention relates to the controlled dispensing of fluids in adhesive applications for electronic devices, and particularly to improvements in the control of the amount of fluid discharged from a fluid-filled syringe during the dispensing process. Background Technology

[0002] In the semiconductor industry, adhesive fluids (typically epoxy resin) used to bond electronic components are contained in disposable syringes made of deformable materials such as plastic. This epoxy resin-based adhesive fluid is dispensed onto the substrate as an adhesion method when bonding semiconductor chips to other related devices. In particular, among the different methods of dispensing epoxy resin, time-pressure dispensers are pneumatic dispensers that allow epoxy resin to be discharged directly from a plastic syringe. Time-pressure dispensers are user-friendly because they require no cleaning and offer plug-and-play operation to minimize setup time.

[0003] However, to dispense epoxy resin, a time-pressure dispenser needs to be connected to a pneumatic source that provides air pulses at regulated pressure to drive and move a piston located in the syringe. The piston forces the epoxy resin out of a nozzle at the opposite end of the syringe. During this pneumatic dispensing process, the air pulses cause the plastic syringe to expand significantly in both the radial and axial directions due to the low Young's modulus of the plastic material. In many cases, the seal between the syringe wall and the piston fails or deteriorates noticeably after multiple dispensing cycles, especially when high air pressures are applied. One reason is that the deformation of the syringe wall at the sealing interface is greater than that of the piston, resulting in a gap between them. Compressed air can then pass through the gap through the piston, being introduced directly into the epoxy resin in the form of bubbles. Besides the bubbles that escape along with the epoxy resin at the nozzle during dispensing, the bubbles remaining in the epoxy resin cannot escape. Epoxy resin also seeps through the gap and accumulates above the piston. Dispensing problems arise due to residual air and epoxy resin leakage that occurs during multiple dispensing cycles.

[0004] Using metal syringes can help overcome the aforementioned problems because the high Young's modulus of metal increases the syringe's hardness. However, metal syringes are not widely used due to their high cost and low reusability. Furthermore, cleaning the syringe after use is time-consuming, and if epoxy resin has cured inside, it may be impossible to clean it at all. In contrast, plastic syringes are more economical and convenient for single use.

[0005] Advantageously, the reliability of plastic syringes can be improved by reducing the degree of deformation experienced by the syringe during fluid dispensing, while avoiding at least some of the aforementioned disadvantages faced by conventional syringes currently in use. Summary of the Invention

[0006] Therefore, the object of the present invention is to provide a device for minimizing the expansion of a conventional disposable syringe made of a deformable material during a dispensing operation using a syringe.

[0007] Therefore, the present invention provides a syringe housing for sealing a syringe containing a fluid to be dispensed, the syringe housing comprising: a space within the syringe housing sized to accommodate a syringe; an opening at a first end of the syringe housing through which the syringe is inserted; a nozzle at a second end of the syringe housing, the second end being opposite to the first end and configured at the second end to engage a dispensing tip of the syringe; and a syringe adapter detachably coupled to the syringe housing for retaining the syringe after it has been inserted into the syringe housing, the syringe adapter including a pneumatic connector connectable to a gas source for introducing gas into an air chamber enclosed within the syringe housing and the syringe, the gas being operable in use to apply force within the syringe to drive the dispensing of fluid through the nozzle.

[0008] These and other features, aspects, and advantages will become better understood by referring to the specification, the appended claims, and the drawings. Attached Figure Description

[0009] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0010] Figure 1 This is a side view of the syringe housing of a syringe according to a first preferred embodiment of the present invention;

[0011] Figure 2 yes Figure 1 A cross-sectional side view of the syringe shell that has been inserted into a conventional syringe;

[0012] Figure 3 yes Figure 1 An exploded perspective view of the syringe casing;

[0013] Figure 4 This is a side view of the syringe housing of a syringe according to a second preferred embodiment of the present invention;

[0014] Figure 5 yes Figure 4 A cross-sectional side view of the syringe shell already inserted into a conventional syringe; and

[0015] Figure 6 yes Figure 4 An exploded perspective view of the syringe casing.

[0016] In the accompanying drawings, the same parts are indicated by the same reference numerals. Detailed Implementation

[0017] During the dispensing cycle, the time-pressure dispenser supplies air pressure to pressurize the syringe to the set pressure used for the dispensing process. Plastic syringes inevitably expand when subjected to this pressure. The extent of expansion varies with the applied air pressure; if the pressure is too high, the expansion of the syringe can affect the seal between the syringe wall and the internal piston.

[0018] According to two preferred embodiments of the invention described herein, the expansion of the syringe can be reduced by air pressure relief and / or mechanical reinforcement.

[0019] Figure 1 This is a side view of a syringe housing assembly 10 for a syringe according to a first preferred embodiment of the present invention, the syringe containing fluid to be dispensed, this embodiment utilizing the concept of air pressure elimination. The fluid may be an adhesive fluid such as epoxy resin. The syringe housing assembly 10 includes a syringe housing 12 having an internal space, a nozzle 16 located at the tip of the syringe, and a syringe cap 14 for positioning the syringe relative to the syringe housing 12. The internal space is sized to accommodate and receive the syringe. The syringe cap 14 can be screwed onto the syringe housing 12 before the syringe is inserted into the syringe housing 12. After the syringe is inserted, the nozzle 16 is configured to engage the dispensing tip of the syringe to dispense the fluid contained in the syringe.

[0020] Syringe adapter 18 in opening 34 (see Figure 3 The syringe adapter 18 is detachably connected to the syringe housing 12 at the top, with an opening 34 located at the top of the syringe housing 12 (i.e., opposite the tip) to connect the syringe to the pneumatic connector 20 after the syringe is inserted into the syringe housing 12. The syringe can be inserted into the syringe housing 10 through the opening 34. The syringe adapter 18 is secured to the syringe housing 12 by an adapter lock 22, which is designed to screw onto the top of the syringe housing 12 to retain the syringe adapter 18 when it is attached to the syringe housing 12. Other types of locking mechanisms may also be used to secure the syringe adapter 18 to the syringe housing 12. After attachment, the syringe adapter 18 is operable to hold the syringe inserted into the syringe housing 10.

[0021] Figure 2 yes Figure 1The image shows a cross-sectional side view of the syringe housing 24 already inserted into a conventional syringe 24. The syringe 24 is typically made of plastic. The syringe 24 has a piston 26 that slides within the syringe 24 to provide driving force for discharging fluid contained within the syringe 24 through a nozzle 16 from the tip of the syringe housing 12. Gas is introduced via a pneumatic connector 20, which may include air 34 supplied in the form of compressed air. The pneumatic connector 20 is connected to a source of compressed air (not shown) for introducing air 34 into an air chamber 32 formed between the syringe adapter 18, the syringe housing 12, and the piston 26. The air chamber 32, in fluid communication with the piston 26, receives air pressure from the introduced air 34, which exerts a force within the syringe 24 to push the piston 26 in the direction of the nozzle 16, thereby distributing fluid through the nozzle 16 by discharging fluid from the syringe 24.

[0022] It is worth noting that, according to this embodiment of the invention, after the syringe 24 is inserted, air pressure is further generated in the gap 25 between the deformable wall of the syringe 24 and the wall of the syringe housing 12 to prevent excessive deformation of the wall of the syringe 24 when receiving air pressure from the introduced air 34 to drive the piston 26. Therefore, when air 34 is introduced into the air chamber 32 via the syringe air inlet 21 formed in the syringe adapter 18, air 34 is simultaneously introduced into and received in the gap 25 via the housing air inlet 23 also formed in the syringe adapter 18, which is between the syringe 24 and the syringe housing 12. Since the air pressure in the air chamber 32 inside the syringe 24 is substantially the same as or equal to the air pressure in the gap 25 outside the syringe 24, the wall of the syringe 24 will be restricted from expanding or displacing by the air pressure in the gap 25 when air 34 is introduced to drive the piston 26 to dispense the adhesive fluid.

[0023] To maintain and balance the air pressure inside and outside the syringe 24, the air chamber 32 and gap 25 inside the syringe housing 12 should be sealed and isolated from the surrounding atmosphere. Thus, the syringe O-ring 28 seals the gap 25 between the syringe 24 and the syringe adapter 18, the adapter O-ring 30 seals the gap between the syringe adapter 18 and the syringe housing 12, and the cap O-ring 33 seals the gap between the syringe housing 12 and the syringe 24.

[0024] The purpose of this air pressure relief is to minimize expansion or displacement caused by the air pressure applied to the outer surface of the syringe 24 to counteract any expansion or displacement caused by the air pressure used to drive the piston 26 to dispense the adhesive fluid. Ideally, the air pressure used to counteract expansion is equal to the air pressure received by the piston 26 for the dispensing operation.

[0025] During the time-pressure distribution process of syringe 24, the cancellation of air pressure not only allows the inside of the syringe to be pressurized, but also allows the outside of the syringe to be pressurized simultaneously with equal pressure. Thus, the pressure acting on the inner wall of syringe 24 cancels out the pressure acting on the outer wall of syringe 24. Therefore, syringe 24 is restricted from expanding or shifting due to air pressure 34.

[0026] Because there are slight dimensional differences in syringes 24 from different brands on the market, the air pressure relief method is designed to provide some tolerances to accommodate the geometric differences present in syringes from different brands. Advantageously, the syringe housing 12 is not contaminated by the adhesive fluid because it only houses the syringe 24 but does not directly contact the adhesive fluid, allowing the syringe housing 12 to be immediately reused without cleaning.

[0027] Figure 3 yes Figure 1 An exploded perspective view of the syringe housing assembly 10 shows how the syringe housing assembly 10 can be assembled and used. First, the syringe 24 is inserted into the syringe housing 12. Then, the nozzle 16 can be screwed into the syringe housing 12 to contact the tip of the syringe 24, such that fluid ejected from the syringe 24 passes through the nozzle 16 during dispensing. At the top of the syringe housing 12, a syringe adapter 18, including a pneumatic connector 20, is attached to the syringe housing 12. An adapter locking member 22 screws onto the top of the syringe housing 12, with the syringe adapter 18 positioned between the adapter locking member 22 and the syringe housing 12 to lock the syringe adapter 18 onto the syringe housing 12. An air hose (not shown) can then be attached to the pneumatic connector 20 to inject air into the air chamber 32 to drive the piston 26 to eject fluid from the syringe 24.

[0028] After the fluid in syringe 24 is exhausted, syringe 24 can be removed from syringe housing 12 to replace it with a new syringe.

[0029] Figure 4This is a side view of a syringe housing assembly 40 for a syringe 50 according to a second preferred embodiment of the present invention, which utilizes the concept of mechanical structural reinforcement. The syringe housing assembly 40 includes a syringe housing 42 for insertion into a conventional syringe 50 and a nozzle 48 that can be located at the tip of the syringe 50. In this embodiment, the syringe housing 42 includes a flexible structure 43. In the unbiased position, the flexible structure 43 allows sufficient space for insertion of the syringe 50. After the syringe 50 is inserted into the syringe housing 42, the flexible structure 43 is movable from its unbiased position to a biased position when a flexible locking member 44 is screwed onto the flexible structure 43, such that the flexible fingers of the flexible structure 43 terminating at the housing tip 46 of the syringe housing assembly 40 are configured to bias the syringe 24. This biasing of the flexible structure 43 mechanically locks the axial length of the syringe 24 and the cylindrical outer wall of the syringe 24 to provide rigidity to the walls of the syringe 24 after insertion. The nozzle 48 can also be locked into place by the flexible structure 43.

[0030] At the top of the syringe housing 42, a syringe adapter 52 is mounted on the syringe housing 42 so that the syringe 50 can be connected to the pneumatic connector 54 after the syringe 50 is inserted into the syringe housing 42 during use.

[0031] Figure 5 yes Figure 4 A cross-sectional side view of the syringe housing assembly 40, which has been inserted into a conventional syringe 50. At the tip of the syringe 50, a nozzle 48 is attached to the syringe 50 and locked in place by fingers of a flexible structure 43, which is biased by the action of screwing a flexible locking member 44 onto the flexible structure 43.

[0032] like Figure 5 As shown, in this embodiment, there is no gap between the syringe housing 42 and the cylindrical wall of the syringe 50. During the dispensing of fluid from the syringe 50 through the nozzle 48, the flexible structure 43 resists deformation of the syringe 50 when pneumatic pressure is introduced and acts on the piston 51 in the syringe 50. At the top of the syringe housing assembly 40, the syringe adapter 52 is pushed into the space within the syringe 50 via an interference fit between the syringe O-ring 56 located on the outer surface of the syringe adapter 52 and the inner wall of the syringe 50. When air 58 is introduced through the pneumatic connector 54 to drive the piston 51, the syringe O-ring 56 forms an airtight seal between the inner wall of the syringe 50 and the syringe adapter 52.

[0033] The mechanical reinforcement is based on the concept of mechanically strengthening the structure of the syringe 50 by inserting it into the syringe housing 42, which is made of a harder material with a higher Young's modulus than the syringe 50. Therefore, the syringe housing 42 is designed such that the outer wall of the syringe 50 is in close contact with the inner wall of the syringe housing 42.

[0034] For ease of installation, the presence of a flexible mechanism in the form of flexible structure 43 provides a degree of radial compliance, allowing insertion of syringe 50 before use. After syringe 50 is inserted into syringe housing 42, flexible locking member 44 is screwed onto and secured near the distal end of the syringe, which is pushed inward by a plurality of fingers forming flexible structure 43 towards housing tip 46. These fingers may be in the form of wedge-shaped members, particularly at housing tip 46. When flexible locking member 44 is fully secured to flexible structure 43, the compliance provided by flexible structure 43 is removed, and the wedge-shaped members clamp the flexible fingers onto syringe 50. The rigidity of syringe housing 42 comes into play to reinforce syringe 50. Thus, syringe 50 gains greater resistance to expansion due to air pressure.

[0035] Figure 6 yes Figure 4 An exploded perspective view of the syringe housing assembly 40. At the bottom end of the syringe housing 42, a flexible structure 43 terminates within a housing tip 46, the housing tip 46 including flexible fingers to clamp and secure the nozzle 48 after it is attached to the syringe 50. A flexible locking member 44 is adapted to screw onto the flexible structure 48 directly above the housing tip 46 to bias the flexible structure 48 onto the syringe 50.

[0036] The syringe 50 can be inserted into the syringe housing 42 from the top, and then the syringe adapter 52 can be inserted into the syringe 50. The syringe O-ring 56 forms an interference fit with the cylindrical wall of the syringe 50. Then, an air hose (not shown) can be attached to the pneumatic connector 54 to inject air into the syringe 50 to drive the piston 51 to eject fluid from the syringe 50.

[0037] It should be understood that when using a time-pressure dispenser to dispense the adhesive liquid contained in syringes 24, 50, the syringe housing device 10, 40 described with reference to the preferred embodiment of the present invention helps to limit the expansion of conventional deformable syringes 24, 50.

[0038] By limiting the expansion or displacement of syringes 24, 50, the syringe housing assembly 10, 40 ensures a reliable seal between the walls of syringes 24, 50 and pistons 26, 51 when dispensing adhesive fluid from syringes 24, 50. This prevents air 34, 58 from being unintentionally injected into the adhesive fluid and prevents leakage of adhesive fluid in the opposite direction through pistons 26, 51. By avoiding these fundamental sealing problems, the dispensing process becomes more consistent and stable.

[0039] Although the invention has been described in considerable detail with reference to certain embodiments, other embodiments are also possible.

[0040] Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

Claims

1. A syringe housing for sealing a syringe containing a fluid to be dispensed, the syringe housing comprising: The space within the syringe housing, the dimensions of which are adapted to accommodate the syringe; The syringe housing has an opening at its first end, through which the syringe can be inserted into the syringe housing; A nozzle, located on the syringe housing at a second end of the syringe housing opposite the first end, is configured at the second end to engage the dispensing tip of the syringe for dispensing liquid from the syringe through the nozzle; A positioning member located on the syringe housing and configured to position the syringe and nozzle relative to the syringe housing; as well as A syringe adapter, detachably connected to the syringe housing, for holding the syringe after it is inserted into the syringe housing, the syringe adapter including a pneumatic connector connectable to a gas source for introducing gas into an air chamber enclosed within the syringe housing and the syringe, the gas being operable in use to apply force within the syringe to drive the dispensing of fluid through the nozzle.

2. The syringe housing of claim 1, further comprising an adapter locking member adapted to screw onto the syringe adapter at the first end of the syringe housing to retain the syringe adapter when the syringe adapter is coupled to the syringe housing.

3. The syringe housing according to claim 1, wherein, The gas includes compressed air, and the air chamber is located between the syringe adapter and the piston within the syringe. The air chamber is configured to draw pressure from the compressed air to apply force to the piston to drive the dispensing of the fluid.

4. The syringe housing according to claim 1, wherein, The syringe housing is sized to create a gap between the deformable wall of the syringe and the wall of the syringe housing after the syringe is inserted, the gap being configured to receive gas introduced simultaneously through the pneumatic connector and the air chamber.

5. The syringe housing according to claim 4, wherein, The syringe adapter also includes a syringe air inlet and a separate housing air inlet, through which gas is introduced into the air chamber and through which gas is introduced into the gap.

6. The syringe housing according to claim 4, wherein, The air pressure in the gap is configured to be substantially equal to the air pressure in the air chamber, such that the deformable wall of the syringe is restricted from expanding by the air pressure in the gap.

7. The syringe housing according to claim 4, wherein, Both the air chamber and the gap are sealed and isolated from the surrounding atmosphere.

8. The syringe housing according to claim 1, wherein, The syringe is configured to be removable from the syringe housing for replacement of the syringe, and the positioning member includes a syringe cap that is mounted on a second end of the syringe housing before the syringe is inserted into the syringe housing.

9. The syringe housing according to claim 1, wherein, The syringe housing includes a flexible structure that is movable between a non-biased position and a biased position during syringe insertion to mechanically lock the syringe after insertion.

10. The syringe housing of claim 9, wherein the positioning mechanism includes a flexible locking member operably engaging the flexible structure and biasing the flexible structure to the biased position to mechanically lock the syringe relative to the syringe housing.

11. The syringe housing according to claim 10, wherein, The flexible structure includes flexible fingers terminating at the tip of the syringe housing.

12. The syringe housing according to claim 11, wherein, The flexible locking member is configured to screw onto the flexible finger for biasing the flexible structure.

13. The syringe housing according to claim 12, wherein, The flexible finger is wedge-shaped at the tip of the syringe housing, such that the flexible locking member is fastened to the flexible structure to clamp the flexible finger onto the syringe, thereby reinforcing the syringe.

14. The syringe housing according to claim 10, wherein, The flexible locking element can also operatively lock the nozzle to the second end of the syringe housing.

15. The syringe housing according to claim 9, wherein, The flexible structure is configured to rigidly support the syringe and prevent it from deforming when the gas applies force within the syringe.

16. The syringe housing according to claim 1, wherein, The syringe adapter is connected to the syringe housing via an interference fit between the syringe O-ring located on the outer surface of the syringe adapter and the inner wall of the syringe.

17. The syringe housing according to claim 1, wherein, The syringe shell is made of a harder material with a Young's modulus higher than that of the syringe.

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