Vacuum online sealing method for a heat plate

Abstract

The application discloses a kind of vacuum online sealing methods of heat plate, by the cooperation of sealing glue and plastic film piece, ensure that vacuum online sealing whole process does not leak, and make the suction amount of sealing glue controllable, avoid sealing glue suction heat plate cavity and affect the evaporation-condensation cycle of working medium;Sealing glue, plastic film piece is isolated simultaneously, and the communication of filling hole and outside is solved, the problem of the tooling that filling pipeline and valve cannot be removed during the solidification process of sealing glue is solved, and the reuse efficiency of tooling is improved.The application vacuum online sealing method of heat plate is simple to operate, does not need welding, and has good use effect, and strong scalability.

Description

Technical Field

[0001] This invention relates to the field of heat spreader manufacturing technology, specifically a vacuum online sealing method for heat spreaders. Background Technology

[0002] A vapor chamber, as a functional structural component, mainly consists of a shell, a wick structure or a pulsating heat pipe circuit, and a phase change medium. The shell and the wick structure or pulsating heat pipe circuit enclose a vacuum-sealed cavity. The phase change medium fills the cavity and, driven by the wick or capillary circuit, achieves efficient heat transfer and diffusion through an evaporation-condensation cycle. Vapor chambers possess significantly higher thermal conductivity and temperature uniformity than metals such as copper and aluminum, and have become a major technical means to solve the heat dissipation problem of high heat flux density electronic components, showing broad application prospects in the field of electronic heat dissipation.

[0003] Based on the working principle of phase change heat transfer in a vapor chamber, the vapor chamber cavity needs to maintain a high vacuum level (≤2Pa, excluding the phase change working fluid). If the vacuum level is insufficient, the presence of a large amount of non-condensable gases will affect the working boiling point of the phase change working fluid and its evaporation-condensation cycle rate. Therefore, the vacuum level of the vapor chamber cavity determines its heat dissipation performance and even its yield rate, which places stringent requirements on the filling and sealing processes of the vapor chamber.

[0004] In existing technologies, most methods employ a working fluid filling-vacuum treatment-compression sealing approach: "Vacuum treatment" is typically achieved through heating and evacuation or direct vacuuming, while "compression sealing" usually involves mechanically flattening the filling tube followed by spot welding or arc welding. This method reduces the difficulty of filling and sealing, but suffers from problems such as difficulty in controlling the filling volume and vacuum level, and leakage during the transition from a temporary mechanical seal to a permanent welded seal. Another approach uses a vacuuming-working fluid filling-compression sealing method: first, the heat spreader is evacuated, then the working fluid is filled, and finally, mechanical flattening and welding are performed. This method solves the problem of precise control of the filling volume and vacuum level, but leakage still occurs during the sealing process. Therefore, online vacuum sealing has become a key process affecting the vacuum level of the heat spreader.

[0005] Patent CN202010836759.9 describes a structure and method for filling and sealing a heat spreader plate. It proposes a structure and method for vacuuming, working fluid filling, and vacuum online sealing, which systematically solves the problem of air leakage during the vacuum online sealing process. However, it has the problems of the sealing adhesive being drawn in more under the negative pressure of the heat spreader plate cavity and the tooling occupying the filling pipeline and valves that cannot be removed during the sealing adhesive curing process. Summary of the Invention

[0006] The purpose of this invention is to provide a vapor chamber online sealing method with a heat spreader that ensures no air leakage throughout the sealing process, allows for controllable sealing adhesive intake, and enables high reuse efficiency of the filling tooling.

[0007] The technical solution to achieve the objective of this invention is: a vacuum online sealing method for a heat spreader, comprising the following steps:

[0008] Step 1: Vacuum the heat exchanger and fill it with phase change working fluid using the filling head and the filling hole of the heat exchanger, and disconnect the filling hole from the outside.

[0009] Step 2: Mix the sealing adhesive thoroughly.

[0010] Step 3: Fill the blind holes of the heat spreader with sealing adhesive and pile the sealing adhesive into and around the blind holes. Empty the air in the blind holes and puncture the thin wall between the blind holes and the filling channel. At this time, the sealing adhesive in and around the blind holes is continuously drawn into the filling channel and the transition channel under the negative pressure of the heat spreader cavity.

[0011] Step 4: Cut out plastic film sheet I of the specified size;

[0012] Step 5: After the sealing adhesive has been absorbed to a certain extent, align the geometric center of the plastic film I with the blind sealing hole and press it on. Squeeze the plastic film I on the blind sealing hole to push the sealing adhesive at the blind sealing hole to the periphery, thereby blocking the continuous absorption of the sealing adhesive and isolating the blind sealing hole from the outside world.

[0013] Step 6: Cut out plastic film sheet II of the specified size;

[0014] Step 7: Take an appropriate amount of sealing adhesive and pile it in the middle area of ​​plastic film II. Remove the filling pipe and valve from the filling head. Align the sealing adhesive on plastic film II with the filling hole and quickly attach it. Squeeze plastic film II on the filling hole to push the sealing adhesive at the filling hole to the periphery, so as to block the suction of the sealing adhesive and isolate the filling hole from the outside.

[0015] Step 8: Let the heat spreader stand still after sealing to complete the automatic curing of the sealing adhesive;

[0016] Step 9: After the sealing adhesive has cured, remove plastic film I and plastic film II, mill off the filling head and the sealing adhesive around the blind hole, and complete the vacuum online sealing of the heat spreader.

[0017] Preferably, the heat spreader is a liquid wick heat spreader or a pulsating heat pipe heat spreader.

[0018] Preferably, the phase change working fluid is distilled water, methanol, ethanol, acetone, Freon, or electronic fluorinated liquid.

[0019] Preferably, the volume of sealing adhesive drawn in through the sealing blind hole and filling hole is smaller than the volume of the filling channel and transition channel.

[0020] Preferably, the settling time of the heat spreader after sealing is not less than the complete curing time of the sealing adhesive.

[0021] Preferably, the heat spreader is provided with a filling head, a filling channel, a sealing blind hole and a transition channel. The filling channel is located inside the filling head and the heat spreader, connecting the heat spreader cavity to the outside. The sealing blind hole is located directly above the filling channel (4-2), and the transition channel is located between the filling channel and the heat spreader cavity.

[0022] Preferably, the sealing adhesive inside the blind sealing hole is stirred with an awl needle to expel the air inside the blind sealing hole.

[0023] Preferably, the sealing adhesive is a high-strength epoxy resin adhesive.

[0024] Preferably, plastic film I and plastic film II are airtight plastic films with a thickness of 0.05 mm.

[0025] Compared with the prior art, the significant advantages of this invention are:

[0026] 1) The use of sealing adhesive and plastic film in this invention ensures that there is no air leakage during the entire vacuum online sealing process, and makes the amount of sealing adhesive absorbed controllable, avoiding the sealing adhesive being sucked into the heat spreader cavity and affecting the evaporation-condensation cycle of the working fluid.

[0027] 2) In this invention, sealing adhesive and plastic film are used to isolate the filling hole from the outside world, which solves the problem of tooling occupation where the filling pipeline and valve cannot be removed during the curing process of sealing adhesive, and improves the reuse efficiency of tooling.

[0028] 3) This invention is simple to operate, requires no welding, has a good sealing effect, and is highly scalable. Attached Figure Description

[0029] Figure 1 This is a flow chart of the vacuum online sealing process of the present invention;

[0030] Figure 2 This is a schematic diagram of the state before the blind hole of the sealing device of the present invention is pierced;

[0031] Figure 3 This is a schematic diagram of the state during the curing process of the sealing adhesive of the present invention;

[0032] Figure 4 This is a schematic diagram showing the state after the vacuum online sealing of the present invention is completed.

[0033] in:

[0034] 1-Heat vapor chamber, 2-Sealing adhesive, 3-Plastic diaphragm I, 4-Plastic diaphragm II;

[0035] 1-1-Hot plate cavity, 1-2-Filling head, 1-3-Filling hole, 1-4-Sealing blind hole, 1-5-Filling flow channel, 1-6-Transition flow channel. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] like Figures 1-4 The diagram shown is a process flow chart and process state schematic diagram of an embodiment of the vacuum online sealing method for a heat spreader plate of the present invention. The heat spreader plate is provided with a filling head 1-2, a filling channel 1-5, a sealing blind hole 1-4, and a transition channel 1-6. The filling channel 1-5 is located inside the filling head 1-2 and the heat spreader plate 1, connecting the heat spreader plate cavity to the outside. The sealing blind hole 1-4 is located directly above the filling channel (4-2), and the transition channel 1-6 is located between the filling channel 1-5 and the heat spreader plate cavity. The specific steps are as follows:

[0038] Step 1: After vacuuming and filling the working fluid into the heat exchange plate 1 through the filling head 1-2 and filling hole 1-3, rotate the valve to disconnect the filling hole 1-3 from the outside.

[0039] Step 2: Mix the sealing adhesive 2 according to the specified ratio and stir until evenly mixed;

[0040] Step 3: Take an appropriate amount of sealing adhesive 2 and fill and pile it into and around the sealing blind hole 1-4. Stir the sealing adhesive 2 in the sealing blind hole 1-4 with an awl needle to expel the air in the sealing blind hole 1-4. Then, pierce the 0.5mm thin wall between the sealing blind hole 1-4 and the filling channel 1-5. At this time, the sealing adhesive 2 in and around the sealing blind hole 1-4 is continuously sucked into the filling channel 1-5 and the transition channel 1-6 under the negative pressure of the heat spreader cavity 1-1.

[0041] Step 4: Cut out plastic film pieces of appropriate size Ⅰ3;

[0042] Step 5: After the sealing adhesive 2 has absorbed a certain amount, press the geometric center of the plastic film I3 onto the sealing blind hole 1-4 and squeeze the plastic film I3 on ​​the sealing blind hole 1-4 to push the sealing adhesive 2 outside the sealing blind hole 1-4 to the periphery, so as to block the continuous absorption of the sealing adhesive 2 and isolate the sealing blind hole 1-4 from the outside. At this time, the filling channel 1-5 and part of the transition channel 1-6 are filled with sealing adhesive 2.

[0043] Step 6: Cut out plastic film sheet II4 of appropriate size;

[0044] Step 7: Take an appropriate amount of sealing adhesive 2 and pile it into the middle area of ​​the plastic film II 4. Remove the filling pipe and valve from the filling head 1-2. Align the sealing adhesive 2 on the plastic film II 4 with the filling hole 1-3 and quickly attach it. Then squeeze the plastic film II 4 on the filling hole 1-3 to push the sealing adhesive 2 outside the filling hole 1-3 to the periphery, so as to block the suction of the sealing adhesive 2 and isolate the filling hole 1-3 from the outside.

[0045] Step 8: Let the sealed heat spreader 1 stand still to complete the automatic curing of the sealing adhesive 2;

[0046] Step 9: After the sealing adhesive 2 has cured, remove plastic film I3 and plastic film II4, and mill away the sealing adhesive 2 around the filling head 1-2 and the sealing blind hole 1-4 to complete the vacuum online sealing of the heat spreader 1.

[0047] Combination Figures 2-4 In a further embodiment, the heat spreader 1 is a pulsed heat pipe heat spreader, that is, the heat spreader cavity 1-1 is in the form of a pulsed heat pipe loop cavity, and the working fluid is acetone.

[0048] In a further embodiment, the sealing adhesive 2 is a high-strength epoxy resin adhesive, which, after complete curing, has the characteristics of high strength, high temperature resistance, corrosion resistance, vibration resistance, and impact resistance, and also has good processing properties such as being able to be ground, drilled, and surface treated.

[0049] In a further embodiment, the volume of sealing adhesive 2 filling and depositing into and around the blind holes 1-4 is approximately 0.3 mL.

[0050] In a further embodiment, plastic film I3 and plastic film II4 are airtight plastic films with a thickness of 0.05mm and a size of approximately 20×20mm after cutting.

[0051] In a further embodiment, the volume of sealing adhesive 2 drawn in through the sealing blind hole 1-4 and the filling hole 1-3 is controlled to be less than 0.1 mL, so that too much sealing adhesive 2 is drawn in and enters the heat spreader cavity 1-1.

[0052] In a further embodiment, the volume of the sealing adhesive 2 piled into the middle region of the plastic film II4 is about 0.3 mL.

[0053] In a further embodiment, the complete curing time of the sealing adhesive is 12 hours, that is, the standing time after the heat spreader 1 is sealed should be no less than 12 hours.

[0054] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for vacuum online sealing of a heat spreader, characterized in that, The steps are as follows: Step 1: Vacuum the heat exchange plate (1) and fill it with phase change working fluid using the filling head (1-2) and the filling hole (1-3) of the heat exchange plate, and disconnect the filling hole (1-3) from the outside. Step 2: Mix the sealing adhesive (2) thoroughly. Step 3: Fill the blind hole (1-4) of the heat spreader (1) with sealing adhesive (2) and pile the sealing adhesive (2) into the blind hole (1-4) and around the blind hole (1-4), empty the air in the blind hole (1-4), and puncture the thin wall between the blind hole (1-4) and the filling channel (1-5). At this time, the sealing adhesive (2) in the blind hole (1-4) and around the blind hole (1-4) is continuously sucked into the filling channel (1-5) and the transition channel (1-6) under the negative pressure of the heat spreader cavity (1-1). Step 4, cut out plastic film sheet I (3) of the specified size; Step 5: After the sealing adhesive (2) has absorbed a certain amount, press the geometric center of the plastic film I (3) onto the sealing blind hole (1-4) and squeeze the plastic film I (3) on the sealing blind hole (1-4) to push the sealing adhesive (2) at the sealing blind hole (1-4) to the periphery, so as to block the continuous absorption of the sealing adhesive (2) and isolate the sealing blind hole (1-4) from the outside world; Step 6, cut out plastic film II (4) of the set size; Step 7: Take an appropriate amount of sealing adhesive (2) and pile it into the middle area of ​​the plastic film II (4). Remove the filling pipe and valve from the filling head (1-2). Align the sealing adhesive (2) on the plastic film II (4) with the filling hole (1-3) and quickly attach it. Squeeze the plastic film II (4) on the filling hole (1-3) to push the sealing adhesive (2) at the filling hole (1-3) to the periphery to block the intake of the sealing adhesive (2) and isolate the filling hole (1-3) from the outside. Step 8: Let the sealed heat spreader (1) stand still to complete the automatic curing of the sealing adhesive (2); Step 9: After the sealing adhesive (2) has cured, remove plastic film I (3) and plastic film II (4), mill off the filling head (1-2), and mill off the sealing adhesive (2) around the sealing blind hole (1-4) to complete the vacuum online sealing of the heat spreader (1).

2. The vacuum online sealing method for a heat spreader according to claim 1, characterized in that, The heat spreader (1) is a liquid-absorbing core heat spreader or a pulsating heat pipe heat spreader.

3. The vacuum online sealing method for a heat spreader according to claim 1, characterized in that, The phase change working fluid is distilled water, methanol, ethanol, acetone, Freon, or electronic fluorinated liquid.

4. The vacuum online sealing method for a heat spreader according to claim 1, characterized in that, The volume of sealing adhesive (2) drawn in through the sealing blind hole (1-4) and filling hole (1-3) is smaller than the volume of the filling channel (1-5) and the transition channel (1-6).

5. The vacuum online sealing method for a heat spreader according to claim 1, characterized in that, The settling time of the heat-soaking plate (1) after sealing shall not be less than the complete curing time of the sealing adhesive (2).

6. The vacuum online sealing method for a heat spreader according to claim 1, characterized in that, The heat spreader is provided with a filling head (1-2), a filling channel (1-5), a sealing blind hole (1-4), and a transition channel (1-6). The filling channel (1-5) is located inside the filling head (1-2) and the heat spreader (1), connecting the heat spreader cavity to the outside. The sealing blind hole (1-4) is located directly above the filling channel (1-5), and the transition channel (1-6) is located between the filling channel (1-5) and the heat spreader cavity.

7. The vacuum online sealing method for a heat spreader according to claim 1, characterized in that, Use an awl needle to stir the sealing adhesive (2) inside the sealing blind hole (1-4) to expel the air inside the sealing blind hole (1-4).

8. The vacuum online sealing method for a heat spreader according to claim 1, characterized in that, The sealing adhesive is made of high-strength epoxy resin.

9. The vacuum online sealing method for a heat spreader according to claim 1, characterized in that, Plastic film I (3) and plastic film II (4) are airtight plastic films with a thickness of 0.05 mm.

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