TWI546177B - Method of forming a heat dissipation plate module - Google Patents

Description

Thin plate type heat dissipation module manufacturing method

The invention relates to a thin plate type heat dissipating module, in particular to a method for dissipating a thinned bottom plate, forming a thinning zone by using a punching and forging technology of a flute, or a stamping type of caulking and filling technology.

The overall thickness of ultra-thin notebooks (including LED LCD screen + mainframe + chassis itself, etc.) has recently been reduced to less than 15mm by the market, in addition to the thickness of CPU + motherboard + battery + mechanical hard disk or solid state semiconductor hard disk In addition to thinning, the use of thinned heat dissipation modules and ultra-thin heat pipes is an extremely important part of the thinning of NB mechanisms.

In view of this, the inventor filed a Chinese patent application on November 28, 2012, the application number is CN201210501553.6. The patent application discloses a long strip-shaped heat dissipating bottom plate, wherein the horizontal plane of the dome-shaped heat dissipating bottom plate is provided with a fleece ditch, so that the thickness of the heat dissipating bottom plate directly above the CPU can be reduced to 0.4 mm or less or any desired thickness as needed. . The side wall of the long beak has a C-shaped rib to hold the heat pipe.

Please refer to FIG. 1A and FIG. 1B. FIG. 1A is a perspective view showing a long strip shape 135 formed on a heat dissipation substrate 130 by a stamping technique. The width of the strip shape 135 is based on the heat pipe 131 that can be accommodated. The long top surface of the heat dissipation base plate 130 is punched out of a plurality of escape ditches 135v by punching technology. The width, position and number of each escape ditches 135v have been carefully calculated. For example, in one embodiment, the heat dissipation base plate 130 has a length of 44.8 mm, and the escape channel is There are six 135vs, one escaping ditches 135v at each end, and the width of the middle four equidistant escape ditches 135v is 3.2mm. The width of each of the escape ditches 135v at both ends is smaller than that of the escape ditches 135v in the middle. Figure 1B is a top plan view of Figure 1A.

Please refer to FIG. 2A for a perspective view showing the forging process of the top surface of the long strip 135 of the heat dissipation substrate 130. The thickness of the top surface of the strip 135 is only half of the original thickness of the heat sink base 130 (before processing). 2B shows a top plan view of FIG. 2A. Please note that the escape ditches have a V-shaped unfilled area near the side of the elongated ridge 135. Subsequently, after the heat pipe 131 is further installed, the ribs are forged to cover the heat pipe 131.

The heat dissipation substrate disclosed in the above patent application is applied to the heat dissipation module of the ultra-thin NB, so that the overall thickness of the heat dissipation module + CPU can be reduced. However, some applications must use a thin-plate heat-dissipating module. The thin-walled heat-dissipating substrate is only 1mm thick, and it is still necessary to accommodate the heat pipe. Therefore, the heat-dissipating thin-plate of the thin-plate heat-dissipating module needs to be thinned by the embedded heat pipe. Area.

In particular, the thin-plate heat-dissipating modules used in advanced tablet PCs are often fan-free. The heat pipes must be long and must be buried in the heat-dissipating thin-bottom plate. Therefore, the area of the heat-dissipating thin-bottom plate must be large, and the component layout and the heat dissipation are avoided. The thin bottom plate interferes, so a plurality of thinned regions of different degrees must be formed in the 1 mm heat-dissipating thin bottom plate. As shown in the schematic view of FIG. 3A, for example, the first zone 210 is thinned by 0.3 mm, the second zone 220 is thinned by 0.4 mm, and the heat pipe zone 305 is thinned to 0.5 mm.

According to the conventional technology, these thinning zones are achieved by means of CNC machining (milling of numerically controlled lathes). However, in practice, the thin-walled heat sink is CNC-turned as described above, which is not only costly but also requires one district and one district. Milling), and for a soft aluminum heat sink with a thickness of only 1mm, there will be difficulties in clamping and the possibility of sticking the knife. In addition, the heat pipe and the heat-dissipating thin-bottom plate are combined into a thin-plate heat-dissipating module. The conventional welding technology firstly applies nickel to the aluminum heat-dissipating base plate, and then performs high-temperature brazing, not only, Significantly increasing the cost of the thermal module, flatness maintenance is a challenge for the already thin (1mm) aluminum heat sink with a low melting point. Due to the welding process and the residual stress after welding, the heat-dissipating thin base plate may be greatly deformed. In view of the above, it is an object of the present invention to provide a thin plate heat dissipation module manufacturing technique to reduce cost and overcome the problems of the prior art.

An object of the present invention is to provide a thin plate type heat dissipation module, in particular to a fanless solderless thin plate type heat dissipation module, wherein the heat dissipation thin bottom plate comprises a plurality of thinned regions of different thicknesses and areas and a heat pipe thinning zone therein. . A plurality of thinned areas of different thicknesses and areas are used to respond to the layout of the components on the motherboard. The heat pipe thinning zone is used to bury a flat heat pipe.

The technology solved by the invention can complete a plurality of thinning zones of different thicknesses and areas by means of split stamping forging or continuous stamping and forging. In the stamping and forging process, the heat pipes can be placed in the heat pipe thinning zone. After that, the hot pipe is riveted and fixed by pressing a small amount of mass material in a local area of the heat dissipating bottom plate beside the heat pipe by a stamping type extrusion technique, in particular, these processes are performed at ambient temperature.

The invention discloses a manufacturing method of a thin plate type heat dissipating module, wherein the heat dissipating bottom plate comprises a heat pipe buried thinning zone and a plurality of thinning zones of the same size or different degrees of thinning, wherein the heat pipe thinning zone is used for burying a flat shape Heat pipe.

Of course, the technique of the present invention can also be applied to a thin plate having one or several thinned regions, and the thin plate is not limited to the application of the heat dissipation module.

The technical solution of the first embodiment of the present invention is to provide a metal heat dissipation substrate including at least one heat pipe thinning zone or a specific thinning zone therein; according to the heat pipe thinning zone or the specific reduction The total mass of the solid block in the thin zone is equal to the total mass of the heat pipe thinning zone or the specific thinning zone after forging, and the number and size of the escape chute, the number and size of the real block are calculated. The escape trough is spaced apart from the real blocks; the first stamping technique is performed according to the calculation to form a plurality of escape troughs in the heat pipe thinning zone or a predetermined zone of the specific thinning zone; a second stamping and forging technique, such that materials of the plurality of solid blocks are replenished to the adjacent escape grooves by the press forging to form the heat pipe thinning zone or the specific thinned zone; After the heat pipe is placed in the heat pipe thinning zone, a third stamping extrusion technique is performed to squeeze a plurality of small metal block shapes on the edge of the heat pipe to the edge of the heat pipe to rive the fixed heat pipe.

In a second embodiment, the present invention discloses a method for manufacturing a thin-plate heat-dissipating module, which is achieved by a stamping and forging filling method. The technical solution of the second embodiment is to provide a metal heat-dissipating bottom plate, including at least one a heat pipe thinning zone or a predetermined zone of a specific thinning zone is disposed therein; applying a first stamping technique to remove the heat pipe thinning zone or the material of the predetermined zone of the specific thinning zone to form a transparent zone; providing one or several Corresponding to a thin metal sheet having a thickness equal to a reserved thickness of the heat pipe thinned region or a predetermined thickness of the specific thinned portion, wherein the metal sheet is slightly smaller than the corresponding transparent area, and the small size means When the thin metal sheet is placed in the transparent areas, there is only a small gap left. When the stamping type extrusion technique is applied, the peripheral edge of the thin metal sheet is extended by the thickness to fill the gap. Forming a tight joint between the two; providing a set of stamped extruded upper and lower molds, the lower mold being provided with a rib ring, the position of the rib ring corresponding to the peripheral edge of the thin metal sheet; Upper mold and lower mold In the second press-type extrusion, the rib ring partially extends the thin metal sheet to form a tight joint with the metal heat-dissipating bottom plate; after the heat pipe is placed in the thinned portion of the heat pipe, a third press-type extrusion technique is performed on the edge of the heat pipe. Several small metal blocks are squeezed from the edge of the heat pipe to rive the fixed heat pipe.

130‧‧‧Dissipation bottom plate

135‧‧‧ long strips

135v‧‧‧ escaping ditches

132‧‧‧ ribs

134‧‧‧ escape trough

110‧‧‧ Thermal Module

131‧‧‧heat pipe

360‧‧‧Through area

136‧‧‧V-shaped unfilled area

310‧‧‧ escape trough

210‧‧‧First District

220‧‧‧Second District

210f‧‧‧The first zone after stamping and forging

220f‧‧‧Second area after stamping and forging

250‧‧‧heat pipe

255‧‧‧Aluminum extrusion

305‧‧‧Rectangular block

320‧‧‧real blocks

400U, 410U‧‧‧Forged upper die

415‧‧‧ ribbed ring

400D, 410D‧‧‧ die

300‧‧‧ Thermal floor

1A is a perspective view of a conventional heat dissipating bottom plate which is formed into a long strip shape and includes an escape ditch; FIG. 1B is a top plan view of a conventional heat dissipating bottom plate; FIG. 2A is a long stripped top surface is forged. FIG. 2B is a top plan view of the long dome-shaped top surface after being forged; FIG. 3A shows a first embodiment of the present invention, the heat-dissipating bottom plate is formed into a plurality of different sizes by stamping and forging technology. After the thinned zone, after the heat pipe is placed, it is fixed by another stamping and forging extrusion method.

3B is a schematic view showing a heat dissipating bottom plate in a plurality of solid blocks and a flute groove in different sizes in a stamping technique according to a first embodiment of the present invention.

Fig. 3C is a schematic view showing the heat dissipating bottom plate of the first embodiment of the present invention comprising a bent heat pipe which is squeezed and fixed to a heat pipe thinning zone.

4A shows a top view of a heat dissipating substrate punched out of a plurality of discrete through-holes by a stamping forging technique in accordance with a first embodiment of the present invention.

Fig. 4B is a cross-sectional view showing the first embodiment of the present invention before the forging, and the rectangular block has a forged upper die and a lower die.

Fig. 4C is a plan view showing the evacuation tank filled with the material of the solid block after the tanning, in accordance with the first embodiment of the present invention.

Figure 4D is a schematic cross-sectional view of the first embodiment of the present invention after forging.

Figure 5A shows a top view before forging, in accordance with a second embodiment of the present invention, in a through slot (or permeable area) has a thin piece of metal with a small gap between them.

Fig. 5B is a schematic cross-sectional view showing a forged upper mold and a lower mold on the upper and lower sides of the thin metal sheet according to the second embodiment of the present invention.

Figure 5C illustrates a cross-sectional schematic view after forging.

In order to make the above-mentioned objects, features and advantages of the present invention more comprehensible, the thin heat-dissipating module according to the present invention will be described in detail below with reference to the accompanying drawings.

The technology of the present invention can be applied not only to an ultra-thin notebook but also to a tablet computer. The present invention discloses a thin-plate type fanless heat dissipation module. For example, referring to FIG. 3A, a heat dissipation thin substrate 300 having a thickness of about 1 mm includes a plurality of different thinned regions: a first region 210f, a heat pipe thinned region 305, and a second region 220f. The size and extent of each zone are the same or different. For example, the first zone 210f is thinned by 0.3 mm, the second zone 220f is thinned by 0.4 mm, and the heat pipe thinned zone 305 is thinned to 0.5 mm. The heat pipe thinning zone 305 has a heat pipe 250 attached thereto. Among them, the heat pipe 250 is fixed by the stamping and forging technology self-heating pipe thinning zone 305 edge type extruded aluminum material 255 (when the heat dissipation thin bottom plate is aluminum). The extruded aluminum material does not need to be continuous, as shown in Fig. 3A, the extruded aluminum material 255 is formed in sections at the edge of the heat pipe 250. The extruded aluminum material 255 is a material from the heat sink base plate at the edge of the heat pipe, and is not an additional material. The other heat pipe thinning zone 305 is not limited to the elongated shape shown in Fig. 3A, and it may have a long strip shape which is bent as shown in Fig. 3C or two (or more) bent long strips ( Not shown).

According to the first embodiment of the present invention, the first region 210f, the heat pipe thinning region 305, and the second region 220f are calculated according to the basic physical principle of mass incompatibility, and the number of the escape slots 310 in each region is calculated. The dimensions are spaced apart by the actual block 320 and are punched out in one or more times by stamping techniques.

According to the calculation of the basic physical principle of the above-mentioned mass extinction, a plurality of escape chutes 310 are punched out in each zone. Between the escape chute 310 and the escape chute 310 is a solid block 320. According to the degree of thinning, each zone has 310 number and size of the escape trough, 320 pieces and size of the real block. Figure 4A shows the result of this. The first zone 210 and the second zone 220 are referred to as the result of the first stamping forming the escape block 310 between the material blocks 320.

4A to 4D are an example of one of the zones, illustrating the flow and calculation process of the above stamping and forging. Figure 5A illustrates a top view of the heat-dissipating thin backplane 300 being punched out of the punch by a plurality of discrete perforations as the escape chute 310. Figure 5B illustrates a cross-sectional view prior to forging. The heat pipe thinning zone 305 has a forged upper die 400U and a lower die 400D on the upper and lower sides of the solid block 320. FIG. 5C illustrates a top view of the escape chute 310 after being filled by the material of the solid block 320 after forging, and the heat pipe thinning zone 305 is formed by punching and forging to form a rectangular thin block 305f. Figure 5D shows a schematic cross section after forging.

As mentioned above, the number n and the size of the escape trough are calculated according to the total mass of the plurality of solid blocks 320 equal to the total mass of the stamping forging zone, and the actual block to be retained is calculated, and then the reservation is made. The escape chute 310 is stamped and forged to form a permeable escape slot 310.

Listed by the formula as follows:

In the above formula, l _i is the length of the i-th solid block 320, W is the width of the rectangular block 305, t ₀ is the plate thickness, and ρ ₀ is the original density of the plate. L is the total length of the rectangular block (ie, the thinned area), ρ _f is the density after forging, and t _f is the thickness after forging. Density after forging: ρ _f will increase, for example: ρ _f = ρ ₀ × 1.1

The above-mentioned rectangular block thinning zone is an example, and therefore should not be limited thereto, and the application can be applied to various shapes, for example, a rectangular shape connecting another small rectangular shape, a circular shape or other irregular shape.

The thinned groove of the heat dissipation thin bottom plate is not limited to the escape groove thinning method described in the first embodiment. A second embodiment of the invention is a forged filling method. First, a plurality of different shapes and different thicknesses are thinned to a predetermined area to be punched into a plurality of through-grooves by punching, and then forged back by a corresponding thin metal piece of a predetermined thickness.

Taking a rectangular thinning zone of one length L×width W as an example, a punching machine is first punched into the through-groove 360, and another elongated thin metal piece 370 of the size L1×W1 is prepared, and the thickness of the thin metal piece 370 is prepared. It is equal to the final target thickness, wherein L1 is slightly smaller than L, and W1 is slightly smaller than W. Then, the elongated thin metal sheet 370 is partially swaged by the punching method, and the hollow space 360 of the heat dissipation thin bottom plate is filled.

5A to 5C illustrate the process of this process. Figure 5A shows a top view of the forged front, in which a thin metal sheet 370 is placed in the through-groove (or permeable area) 360 with a small gap therebetween. Figure 5B shows a schematic cross section. Each of the upper and lower sides of the thin plate 370 has a forged upper die 410U and a lower die 410D. It is worth noting that the lower die has a rib ring 415 corresponding to the edge of the rectangular thin metal sheet 370. When the upper and lower die die forging, the rib ring 415 will provide a local type of squeeze pressure on the contacted thin metal piece. Around the periphery, the edges of the thin metal sheet are thinned by the shape and further connected to the through-hole area 360. FIG. 5C illustrates a cross-sectional view after forging. After the thin plate 370 is forged, the edge is expanded to the side wall of the transparent region 360 due to the thickness reduction and expansion, and the through-hole region 360 is filled, and the thin metal sheet is thinned. The amount is enough to fill the gap between the two. The above rib ring width is about 0.4-2.0 mm.

The invention has the following advantages:

1. For the fabrication of the heat sink base plate of the thin plate type heat dissipation module, it can be shaped outside the stamped heat sink base plate. In the process of hole, step, boss, etc., it is allowed to insert a special stamping and forging extrusion process on the same punching machine in the form of continuous die or segmented engineering die, and simultaneously complete the heat pipe buried in the thinning zone and Other thinning of various shapes and sizes to avoid component interference, the advantages of simple, fast and low cost; unlike the general process, additional CNC milling is required, and only one block can be thinned at a time, which is time-consuming and costly. For the thinning of large-area aluminum or copper base plates, it is possible to avoid the challenge of clamping the workpiece and the soft aluminum material to stick the tool.

2. In the heat pipe of the present invention, the heat pipe thinning zone and other thinning zones, regardless of the number of the thinned zones, the size, the shape and the thickness, can be stamped and forged in the synchronous process, thereby greatly shortening the processing time. And cost.

3. The stamping and forging extrusion technology of the invention is completed on a general punching machine by a simple stamping process, without using an expensive precision CNC machine or a forging machine, which not only has low processing cost, low investment in hardware equipment, and can be greatly reduced. Supply chain and delivery.

4. The heat pipe thinning zone and other thinning zones of the heat dissipating bottom plate in the invention are completed by stamping and forging technology, and have reinforcing effects on the mechanical strength of the thinned zone.

5. The combination of the heat pipe and the heat dissipating bottom plate in the invention also adopts a stamping and forging type extrusion process, and the aluminum material can be locally extruded from the back surface of the heat pipe thinning zone, and then the heat pipe is riveted and fixed. The aluminum material can also be extruded from the front side of the heat pipe thinning zone, and then the heat pipe is riveted and fixed. The riveting action is also completed on the press machine, which has the advantages of simple process and low cost.

6. In the invention, the heat pipe and the heat dissipation bottom plate are riveted and fixed, and the most environmentally-friendly stamping and forging type extrusion technology is adopted. Compared with the welding process, the aluminum heat dissipation bottom plate does not need to be plated with nickel, and the combination with the heat pipe does not require the use of solder paste, It needs to be welded by high temperature in the reflow furnace, so it has the advantages of environmental protection, low cost and labor saving.

7. In the present invention, the heat pipe and the heat sink base plate are riveted and fixed, and are all stamped at ambient temperature. Forging type extrusion technology, unlike the welding process, must be welded by high temperature in the reflow oven. For large-area thin-plate heat-dissipation modules, it is easy to deform the metal heat-dissipation plate due to the release of high-temperature residual stress, which greatly affects the heat dissipation module. Flatness and yield.

The present invention has been described above by way of a preferred example, but it is not intended to limit the spirit of the invention and the inventive subject matter. Those who are familiar with the technology can easily understand and utilize other components or methods to produce the same effect. Modifications made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims (10)

A method for manufacturing a plate type heat dissipation module includes at least the following steps: providing a metal base plate to include a thinned area; the total mass of the solid block according to the thinned area is equal to the thinned area after forging The total mass, the number and size of the escape troughs, the number and size of the real blocks, and the distance between the escape troughs and the real blocks; according to the calculation, the first stamping technology is performed. Forming a plurality of escape slots in the thinned zone; and performing a second stamping and forging technique to cause the materials of the solid blocks to be replenished to the adjacent materials due to the stamping and forging A groove to form the thinned zone. The method for manufacturing a plate type heat dissipation module according to claim 1, wherein the thinning zone is a heat pipe thinning zone, and further comprises placing a heat pipe in the heat pipe thinning zone for a third time. A stamping type extrusion technique is used to rive the heat pipe. A method for manufacturing a plate type heat dissipation module includes at least the following steps: providing a metal bottom plate and a flat heat pipe; designing a heat pipe thinning zone according to the height of the flat heat pipe; and determining a total mass of the solid block according to the heat pipe thinning zone It is equal to the total mass of the heat pipe thinning zone after forging, calculate the number and size of the escape troughs in the heat pipe thinning zone, the number and size of the real material blocks, and make the escape troughs and the real material blocks mutually For the interval; according to the calculation, the first stamping technique is performed to form a plurality of escape grooves in the heat pipe thinning zone; and a second stamping and forging technique is performed to make the materials of the solid blocks Stamping forging And replenishing the adjacent escape grooves to form the heat pipe thinning zone; and placing the heat pipe in the heat pipe thinning zone, performing a third stamping extrusion technique to rive the fixed heat pipe. The method for manufacturing a plate type heat dissipation module according to claim 3, further comprising a plurality of different shapes and different thickness thinning zones, wherein the plurality of thinned area and the degree of thinning are planned according to actual requirements. In the bottom plate, in response to component layout. The method for manufacturing a plate type heat dissipation module according to claim 3, wherein the metal bottom plate is a strip, and the stamping and forging technology is continuous stamping or section stamping and forging to form the plurality of Different thickness and thickness reduction zones and the heat pipe thinning zone. The method for manufacturing a plate type heat dissipating module according to claim 3, wherein the riveting and fixing of the heat pipe is performed by a back surface type of the heat pipe thinning portion of the heat dissipating bottom plate, and the metal plate material is extruded or reduced by the heat pipe. The thin front side of the thin section is extruded to protrude the metal sheet material to fix one of the heat pipes. A method for manufacturing a plate type heat dissipation module comprises the steps of: providing a metal bottom plate and a flat heat pipe; designing a heat pipe thinning zone according to the height of the flat heat pipe; applying a first stamping technique to remove the heat pipe Thinning the material of the zone to form a permeable zone; providing a metal sheet having a thickness equal to a predetermined retention thickness of the heat pipe thinning zone, the metal sheet being slightly smaller than the permeable zone, the dimension being slightly smaller The thin metal sheet still has a small gap when placed in the transparent region, and when the thin metal sheet is subjected to a stamping type extrusion technique, the peripheral edge of the thin metal sheet is extended in thickness due to the thickness reduction, which is sufficient to fill the gap. , so that the two form a close joint; Providing a set of stamped and extruded upper and lower molds, the lower mold being provided with a rib ring, the position of the rib ring corresponding to the four peripheral lines of the thin metal sheet, applying a second stamping type to The ribbed ring is partially extended to form a tight joint with the metal heat sinking bottom plate; and after the heat pipe is placed in the heat pipe thinning zone, a third stamping extrusion technique is performed to rive the fixed heat pipe. The method for manufacturing a plate type heat dissipation module according to claim 7, wherein the rib ring width is about 0.4-2 mm. The method for manufacturing a plate type heat dissipating module according to claim 7, wherein the riveting and fixing of the heat pipe is performed by a back surface type of the heat pipe thinning portion of the heat dissipating thin bottom plate to protrude the metal plate material or by the heat pipe. The front side of the thinned area is extruded to protrude the metal sheet material to fix the heat pipe. The method for manufacturing a plate type heat dissipation module according to claim 7, further comprising a plurality of thinned regions of different shapes and different thicknesses, each of the thinned regions being corresponding to a thin metal piece, simultaneously or in stages A second stamping type is applied, and the thin metal sheets are stamped and compacted to be tightly fixed in the through-hole regions.