A pressurizing device and pressurizing method in chip mounting process

Abstract

The present invention relates to a pressurizing device and a pressurizing method in a chip mounting process, comprising a lever, on which a rotating shaft is horizontally mounted, the rear end of the lever is hoisted by a steel wire rope, the steel wire rope is connected to a load after passing around a pulley, a pressure head assembly is mounted on the bottom surface of the front end of the lever, and a pressure block at the bottom end of the pressure head assembly applies a vertical downward force to a chip below, thereby forming a chip pressurizing mechanism; a cam is arranged above the lever between the rotating shaft and the steel wire rope, and as the cam rotates, the cam applies a downward force to a lever below to release the downward pressure of the pressure head assembly on the chip; a downward, continuous and stable pressing force is applied to the chip through the steel wire rope and the lever by the load, and the cam rotates to slowly apply a force to the lever to offset the load to release the pressing of the chip, thereby effectively ensuring the continuous, uniform and stable chip mounting, and being suitable for the synchronous mounting of multiple rows of chips, greatly facilitating the use in chip mounting, and particularly suitable for the mounting of chips in different occasions such as heating.

Description

Technical Field

[0001] The present invention relates to the technical field of chip mounting, in particular to a pressurizing device and a pressurizing method in a chip mounting process. Background Art

[0002] Chip mounting technology based on low-temperature sintering of metal paste can not only provide reliable mechanical properties, but also has excellent heat resistance and heat dissipation performance, and is expected to provide a reliable chip packaging environment for the third-generation wide bandgap power semiconductors. Chip mounting technology based on low-temperature sintering of metal paste uses the low-temperature sintering phenomenon of metal particles to achieve the connection between the particles and the chip and substrate while achieving the sintering connection of the particles themselves, forming a "sandwich" structure of chip / sintered metal / substrate.

[0003] The process temperature of the chip mounting technology based on metal paste sintering is 150-300°C. During the process, a certain pressure (0-20MPa) needs to be applied to the chip to obtain a uniform bonding layer and meet the required bonding strength.

[0004] It is very challenging to continuously apply uniform pressure to the chip, especially to multiple chips at the same time, to ensure the consistency of the chip mounting bonding layer during the metal paste sintering process. The difficulties are mainly reflected in:

[0005] 1) In actual operation, since the level of each chip on the substrate may be different, if the same pressure plate is used to contact and apply force to multiple chips at the same time, it will not be possible to ensure that each chip is subjected to uniform pressure;

[0006] 2) When chips of different sizes are mounted at the same time, the pressures required are different, and the required pressure cannot be applied to multiple chips at the same time through the same pressing plate;

[0007] 3) During the sintering process of the metal slurry, its overall thickness will shrink to a certain extent, and the shape of the "sandwich" structure will continue to change, which will make it difficult to apply a uniform and stable pressing force to the chip. Summary of the invention

[0008] In view of the shortcomings of the above-mentioned existing production technology, the applicant provides a pressurizing device and a pressurizing method in the chip mounting process with a reasonable structure, thereby effectively ensuring the continuous, uniform and stable chip mounting, and is suitable for the synchronous mounting of multiple rows of chips, which greatly helps the use in chip mounting, especially for the mounting of chips in different occasions such as heating.

[0009] The technical solution adopted by the present invention is as follows:

[0010] A pressurizing device in a chip mounting process comprises a lever, a rotating shaft is horizontally mounted on the lever, and the lever swings with the axial direction of the rotating shaft as the center of a circle; the rear end of the lever is hoisted by a wire rope, and the wire rope is connected to a load after passing around a pulley, and a pressure head assembly is mounted on the bottom surface of the front end of the lever, and a pressure block at the bottom end of the pressure head assembly applies a vertical downward force to the chip below, forming a chip pressurizing mechanism; a cam is arranged above the lever between the rotating shaft and the wire rope, and as the cam rotates, the cam applies a downward force to the lever below to release the downward pressure of the pressure head assembly on the chip.

[0011] As a further improvement of the above technical solution:

[0012] A plurality of levers parallel to each other are installed at intervals along the length direction on the rotating shaft, the rear end of each lever is hoisted with corresponding steel wire ropes, pulleys and loads, and the front end of each lever is installed with corresponding pressure head assemblies, forming a plurality of pressure mechanisms corresponding to the plurality of chips one by one; a horizontal pressure plate is arranged between the cam and the lever, and the pressure plate is arranged parallel to the rotating shaft, and the rotation of the cam acts on the plurality of levers synchronously downward through the pressure plate.

[0013] It also includes a supporting plate, with side plates installed on the left and right sides of the supporting plate respectively, and the two side plates jointly install the rotating shaft; the two side plates located behind the rotating shaft also jointly install a camshaft, the cam is mounted on the camshaft, and the end of the camshaft is connected to a motor; the two ends of the pressure plate are elastically supported on the two side plates below the camshaft.

[0014] The sides of the side plates facing each other are respectively concavely provided with accommodating cavities, in which supporting blocks are fixedly installed, and in which vertical elastic members are installed, the tops of the elastic members extend out of the supporting blocks, and the bottoms of the elastic members are connected with the bottoms of the pressing plates, and the two groups of elastic members jointly support the pressing plates from both ends.

[0015] Rear brackets are installed at intervals on the support plate located behind the side plate, a crossbeam is installed between the two rear brackets, and hanging brackets corresponding to the pulleys are installed at intervals along the length direction on the crossbeam, and the pulleys are rotatably installed at the bottom of the hanging brackets.

[0016] A base plate is installed on the bottom surface of the support plate, and a guide rail is installed on the base plate along the front-to-back direction. The guide rail is equipped with the bottom surface of the support plate, and the support plate moves forward and backward along the guide rail relative to the base plate under external power driving; a guide rail is installed on the base plate in front of the support plate along the left-right direction, and a substrate is installed on the guide rail. A plurality of chips corresponding to the pressurizing mechanism are placed on the substrate along the left-to-right direction, and the substrate moves left and right relative to the base plate along the guide rail under external driving force.

[0017] The top surface of each single lever is installed with supports at intervals on the left and right, and a roller is rotatably installed between the two supports; the roller is located below the pressure plate, and when the pressure plate moves downward, it applies forces to the upper part of the circumferential wall of the roller.

[0018] A group of pressure head assemblies are installed at the lower part of the front end of the lever, or multiple groups of pressure head assemblies are installed at intervals along the length direction of the lever; the structure of a single group of pressure head assemblies is: it includes a supporting shell, the top of the supporting shell is inserted into the lever, and the pin passes through the upper part of the supporting shell and the lever to fix them relatively; a small spring is installed in the inner cavity of the supporting shell, and the bottom end of the small spring is connected to a pressure block, and the pressure block extends downward from the supporting shell; the bottom end of the pressure block is set to a convex spherical structure.

[0019] A rotating seat is rotatably installed at the front end of the lever, and the rotating seat is rotatably installed relative to the lever via an axis in the left and right horizontal directions. A group of pressure head assemblies are installed on the bottom surface of the rotating seat, or multiple groups of pressure head assemblies are installed on the bottom surface of the rotating seat at intervals along the front and rear directions; a pressure block is installed at the center of the bottom end of each group of pressure head assemblies, and the bottom surface of the pressure block is a plane or an outward convex spherical surface.

[0020] A pressurizing method of a pressurizing device in a chip mounting process comprises the following steps:

[0021] The cam rotates to the position farthest from the pressure plate in the axial direction, that is, the cam applies force downward to the rear section of the lever through the pressure plate, so that the lever presents a state of high front and low rear under the downward pressure of the rear section;

[0022] Adjust the weight of the load at the end of each wire rope according to the preset requirements. The weight of the load is directly related to the pressure applied by the final pressure head assembly to the chip;

[0023] When the pressure head assembly is located at the preset position above the corresponding chip, the cam rotates, gradually reducing the distance it pushes the pressure plate downward, and the pressure plate gradually moves upward in contact with the outer wall of the cam. Under the continuous pull of the load, the rear end of the lever gradually swings upward with the pressure plate, and the front end of the lever swings downward accordingly and gradually moves downward toward the chip below.

[0024] Until the cam shaft is at the position closest to the pressure plate, the force applied downward by the pressure plate to the lever is minimal or even zero. The lever is continuously applied with an upward force by the load at the rear end through the wire rope, so that the front end of the lever applies downward pressure to the chip below through the pressure head assembly, thereby achieving stable pressing of the chip.

[0025] The beneficial effects of the present invention are as follows:

[0026] The invention has a compact and reasonable structure and is easy to operate. The load is applied to the chip through the steel wire rope and the lever to apply a downward, continuous and stable pressing force, and the rotation of the cam slowly applies a force to the lever to offset the load to release the pressing of the chip, which effectively ensures the continuous, uniform and stable pressing of the chip, and is suitable for the synchronous pressing of multiple rows of chips, which greatly helps the use in chip mounting, and is especially suitable for the pressing of chips in different occasions such as heating.

[0027] In the present invention, by synchronously setting multiple groups of pressurizing mechanisms on the rotating shaft, it can be suitable for synchronous press-fitting of multiple chips; by two groups of pressurizing devices facing each other, or by arranging multiple press head assemblies in parallel at the front end of the lever, two or even multiple rows of chips can be press-fitted at the same time, which can greatly improve the efficiency of chip mounting;

[0028] In the present invention, by providing a small spring and a pressure block on the bottom of the spherical structure, the chip can be reliably pressed, which effectively helps to improve the uniformity and stability of the force applied to the chip.

[0029] In the present invention, the pressure applied to the chip can be adjusted by changing the weight or quantity of the load, such as adjusting the weights. The adjustment is convenient, fast and reliable, and can be applied to the rapid adjustment of pressure in different scenarios. It can also achieve different clamping forces on different chips under synchronous pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the present invention.

[0031] Figure 2 for Figure 1 sectional view of .

[0032] Figure 3 The figure is a schematic diagram of the installation of the pressurizing mechanism between the side plates on both sides of the present invention.

[0033] Figure 4 The present invention is a schematic diagram of the installation of the lever end pressure head assembly.

[0034] Figure 5 for Figure 4 Schematic diagram of the structure of the medium pressure head assembly.

[0035] Figure 6 This is a force analysis diagram when two or more rows of pressure head assemblies are arranged on a single lever of the present invention.

[0036] Figure 7 Another schematic diagram of the installation of the lever end pressure head assembly of the present invention is shown.

[0037] Figure 8 It is a schematic diagram of the installation of the lever on the rotating shaft of the present invention.

[0038] Fig. 9 This is a schematic diagram of the cam rotation force application principle in the present invention.

[0039] Fig.10 This is a schematic diagram of the pressurizing device of the present invention before synchronously applying pressure to a single row of chips.

[0040] Fig.11 It is a schematic diagram of the pressurizing device of the present invention applying pressure to a single row of chips synchronously.

[0041] Fig.12 This is a schematic diagram of the pressurizing device of the present invention applying pressure to two rows of chips.

[0042] Fig.13 It is a schematic diagram of the pressurizing device of the present invention when it is applied to a heating channel.

[0043] Among them: 1. Bottom plate; 2. Lever; 3. Press head assembly; 4. Press plate; 5. Camshaft; 6. Load; 7. Rear bracket; 8. Rotating seat; 9. Heating channel; 10. Chip;

[0044] 11. Support plate; 12. Base plate; 13. Side plate; 14. Rotating shaft; 15. Accommodating cavity; 16. Retaining ring;

[0045] 21. roller; 22. support;

[0046] 31. Latch; 32. Support shell; 33. Small spring; 34. Press block; 35. Spherical structure;

[0047] 41. Support block; 42. Elastic member;

[0048] 51. Cam; 52. Motor;

[0049] 61. Wire rope; 62. Pulley; 63. Hanging bracket;

[0050] 91. Channel entrance; 92. Channel exit; 93. Mounting pressurization position. DETAILED DESCRIPTION

[0051] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0052] like Figure 1 and Figure 2 As shown, a pressurizing device in a chip mounting process of the present embodiment includes a lever 2, on which a rotating shaft 14 is horizontally mounted, and the lever 2 swings with the axial direction of the rotating shaft 14 as the center of a circle; the rear end of the lever 2 is hoisted by a wire rope 61, and the wire rope 61 is connected to a load 6 after passing through a pulley 62, and a pressure head assembly 3 is mounted on the bottom surface of the front end of the lever 2, and a pressure block 34 at the bottom end of the pressure head assembly 3 applies a vertical downward force to the chip 10 below, thereby forming a pressurizing mechanism for the chip 10; a cam 51 is arranged above the lever 2 between the rotating shaft 14 and the wire rope 61, and as the cam 51 rotates, the cam 51 applies a downward force to the lever 2 below to relieve or even release the downward pressure of the pressure head assembly 3 on the chip 10.

[0053] The load 6 applies a downward, continuous and stable pressing force to the chip 10 through the wire rope 61 and the lever 2, and the rotation of the cam 51 slowly applies a force to the lever 2 to offset the load 6 to release the pressing of the chip 10, effectively ensuring the continuous, uniform and stable chip pressing.

[0054] When in use, the pressurizing mechanism in this embodiment generates a constant tension inside the wire rope 61 through the weight of the load 6 itself, and applies the tension to the rear end of the lever 2, thereby helping the front end of the lever 2 to apply a relatively stable constant pressure to the chip 10 through the pressure head assembly 3.

[0055] A plurality of levers 2 are installed on the rotating shaft 14 in parallel at intervals along the length direction. The rear end of each lever 2 is hoisted with a corresponding steel wire rope 61, a pulley 62 and a load 6. The front end of each lever 2 is installed with a corresponding pressure head assembly 3, forming a plurality of pressure mechanisms corresponding to the plurality of chips 10 one by one. A horizontal pressure plate 4 is arranged between the cam 51 and the lever 2. The pressure plate 4 is arranged parallel to the rotating shaft 14. The cam 51 rotates downward through the pressure plate 4 to synchronously act on the plurality of levers 2.

[0056] In this embodiment, a pressing force is applied to the corresponding chip 10 through the corresponding pressure head assembly 3 by setting the corresponding load 6. The weight or number of the load 6 can be changed to meet the corresponding pressing force requirements. For example, the pressure applied to the chip 10 can be adjusted by adjusting the weight and number of weights. The adjustment is convenient, fast and reliable, and different pressing forces can be applied to different chips 10 under synchronous pressure. It can also be suitable for rapid adjustment of pressure in different scenarios.

[0057] In this embodiment, a single cam 51 is used to relieve or release the pressing force on multiple chips 10 through the same pressing plate 4. The structure is simple, reasonable and ingenious, and the automation of synchronous pressing of the chips 10 is effectively realized.

[0058] It also includes a supporting plate 11, on the left and right sides of which are respectively installed side plates 13, and the two side plates 13 are jointly installed with a rotating shaft 14; the two side plates 13 located behind the rotating shaft 14 are also jointly installed with a camshaft 5, and a cam 51 is mounted on the camshaft 5, and a motor 52 is connected to the end of the camshaft 5; the two ends of the pressure plate 4 are elastically supported on the two side plates 13 below the camshaft 5; thereby, the supporting plate 11 and the side plates 13 are used to reliably support and install the pressurizing mechanism, especially multiple groups of pressurizing mechanisms, to help ensure the stability and reliability of the pressing of the chip 10.

[0059] like Figure 3As shown, the facing sides of the side plates 13 are respectively concavely provided with accommodating cavities 15, and a supporting block 41 is fixedly installed in the accommodating cavity 15. A vertical elastic member 42 is installed in the supporting block 41. The top of the elastic member 42 extends out of the supporting block 41, and the bottom end of the elastic member 42 is connected with the bottom end of the pressing plate 4. The two groups of elastic members 42 support the pressing plate 4 from both ends, thereby realizing the elastic installation of the pressing plate 4 relative to the side plates 13 on both sides, so that the pressing plate 4 can move downward relative to the side plate 13 when subjected to the pressure of the upper cam 51, and then the pressing plate 4 synchronously applies force downward to the levers 2 of the multiple groups of pressurizing mechanisms.

[0060] Rear brackets 7 are installed at intervals on the support plate 11 located behind the side plate 13, and a crossbeam is installed between the two rear brackets 7. Hangers 63 corresponding to the pulleys 62 are installed at intervals along the length direction on the crossbeam. The pulleys 62 are rotatably installed at the bottom ends of the hangers 63, thereby realizing the installation of pulleys 62 corresponding to multiple sets of pressurizing mechanisms; the force applied to the load 6 is reversed by the pulley 62, so that an upward pulling force can be applied to the rear end of the lever 2.

[0061] In this embodiment, Figure 8 As shown, retaining rings 16 can be symmetrically mounted on the rotating shafts 14 on both sides of the lever 2, and the retaining rings 16 are used to limit and fix the axial position of the lever 2 on the rotating shaft 14;

[0062] Similarly, retaining rings 16 may be symmetrically mounted on the beams on both sides of the hanger 63 , and the retaining rings 16 may be used to limit and fix the position of the hanger 63 in the axial direction of the beam.

[0063] A base plate 1 is installed on the bottom surface of the support plate 11, and a guide rail is installed on the base plate 1 along the front-to-back direction. The guide rail is matched with the bottom surface of the support plate 11, and the support plate 11 moves forward and backward relative to the base plate 1 along the guide rail under external power driving; a guide rail is installed on the base plate 1 in front of the support plate 11 along the left-right direction, and a substrate 12 is mounted on the guide rail, and a plurality of chips 10 corresponding to the pressurizing mechanism are placed on the substrate 12 along the left-to-right direction, and the substrate 12 moves left and right relative to the base plate 1 along the guide rail under external driving force; thereby, the relative position of the support plate 11 relative to the substrate 12 in the front-to-back and left-to-right directions can be quickly adjusted according to actual conditions, that is, the relative position between the pressure head assembly 3 and the chip 10 can be adjusted, thereby improving the convenience and flexibility of use.

[0064] The top surface of each single lever 2 is installed with supports 22 at intervals on the left and right, and a roller 21 is rotatably installed between the two supports 22; the roller 21 is located below the pressure plate 4, and when the pressure plate 4 moves downward, it applies force to the upper part of the circumferential wall of the roller 21 in opposite directions.

[0065] By setting the roller 21, it contacts the upper pressure plate 4 through rolling friction, so that the force applied downward to the lever 2 through the pressure plate 4 is more uniform, and the downward or upward process of the pressure plate 4 is smoother and more reliable, effectively ensuring the continuity, stability and smoothness of the pressure between the front end pressure head assembly 3 of the lever 2 and the chip 10, and there will be no sudden change in the pressure applied to the chip 10 due to the stagnation of the mechanism operation or the uneven force or application.

[0066] In one embodiment, if Figure 4 As shown, a set of pressure head assemblies 3 are installed at the lower part of the front end of the lever 2, or multiple sets of pressure head assemblies 3 are installed at intervals along the length direction of the lever 2;

[0067] like Figure 5 As shown, the structure of the single-group pressure head assembly 3 is: it includes a supporting shell 32, the top of the supporting shell 32 is inserted into the lever 2, and the pin 31 passes through the upper part of the supporting shell 32 and the lever 2 to fix them relatively; a small spring 33 is installed in the inner cavity of the supporting shell 32, and the bottom end of the small spring 33 is connected to a pressure block 34, and the pressure block 34 extends downward from the supporting shell 32; the bottom end of the pressure block 34 is set as a convex spherical structure 35.

[0068] In this embodiment, by providing the small spring 33 and the bottom pressure block 34 of the spherical structure 35 , the chip 10 can be reliably pressed, which effectively helps to improve the uniformity and stability of the force applied to the chip 10 .

[0069] By arranging a plurality of pressure head assemblies 3 at the front end of the lever 2, pressure can be applied to the multiple rows of chips 10 on the substrate 12. During the pressurization process, the small spring 33 in the pressure head assembly 3 is in a compressed state, and the elastic force generated by the small spring 33 is equal to the pressure required by the chip 10. When the chip 10 is subjected to concentrated force due to the change in the thickness of the sintered layer, the adaptive adjustment of the small spring 33 can ensure that the lever 2 distributes the pressure to the different front and rear chips 10 through different pressure head assemblies 3, and generates relatively uniform and consistent pressure on different chips 10, thereby avoiding the situation where a single chip 10 is subjected to excessive force during the pressurization process, and improving and ensuring the stability of the force on the chip 10.

[0070] like Figure 6 It is a force analysis diagram when two or more rows of pressure head assemblies 3 are arranged on a single lever 2, and the distance between two chips 10 is set to a, the distance between the chip 10 close to the shaft 14 and the shaft 14 is b, and the distance between the shaft 14 and the wire rope 61 is c.

[0071] When the pressurization starts, the tension of the wire rope 61 is T, and the pressure on the front and rear chips 10 is F=k*x, where k is the spring elastic coefficient and x is the deformation of the spring at this time. From the force balance of the pressure rod, it can be seen that: T*c=F*(a+b)+F*b.

[0072] As the chip 10 is continuously stressed, the thickness of the sintered layer will change to a certain extent. For example, the thickness change d causes the height of the chip 10 to change to a certain extent. The lever 2 rotates slightly by an angle θ=arctan(d / (a+b)), and the small spring 33 in the pressure head assembly 3 farther from the rotating shaft 14 is further compressed. At this time, the increased compression amount is x1≈d. The force on the chip 10 farther from the rotating shaft 14 is F1=k*(x+x1), and the force on the chip 10 closer to the rotating shaft is F2.

[0073] According to the force balance of lever 2, we can know that:

[0074] T*c=F1*(a+b)+F2*b;

[0075] We can get:

[0076] F2*b=F*(a+b)+F*b-F1*(a+b)=kx*(a+2b)-k*(x+x1)*(a+b)=k*x*bk*x1*(a+b),

[0077] F2=k*x-(a / b+1)*k*x1.

[0078] In the actual production process, the pressure on the chip 10 ranges from 9 to 100 N, the elastic coefficient of the small spring 33 is 0.5 to 3 N / mm, the initial change x of the small spring 33 is 20 to 40 mm, and the maximum change d of the sintered layer thickness is 50 to 100 um;

[0079] Take a = 15mm, b = 50mm, c = 150mm, and substitute into the above analysis, we can know:

[0080] The rotation angle of lever 2 is θ = arctan(d / (a+b))≈d / (a+b)≤0.002;

[0081] The variation range of the pressure on the two chips 10 is (F1-F2) / F=(2+a / b)x1 / x≤1.15%;

[0082] Therefore, the influence of the thickness change of the front and rear chips 10 during sintering on the consistency of the pressing force can be ignored. Considering that the thickness m of the chip 10 is 100-1000um, when the thickness of the two chips 10 is different, resulting in different initial heights of the chip 10, the error of the pressure on the chip 10 is about m / x≤4.5%, and the influence on the sintering of the chip 10 is also small. Therefore, the pressurizing device in this embodiment can be simultaneously applied to the metal sintering process of chips 10 of different heights.

[0083] In another embodiment, Figure 7As shown, a rotating seat 8 is rotatably installed at the front end of the lever 2, and the rotating seat 8 is rotatably installed relative to the lever 2 via an axis in the left and right horizontal directions. A group of pressure head assemblies 3 are installed on the bottom surface of the rotating seat 8, or multiple groups of pressure head assemblies 3 are installed on the bottom surface of the rotating seat 8 at intervals along the front and rear directions; a pressure block 34 is installed at the center of the bottom end of each group of pressure head assemblies 3, and the bottom surface of the pressure block 34 is a plane or an outward convex spherical surface; thereby, through the rotatable installation between the rotating seat 8 and the lever 2, the adaptability of the use of the pressure head assembly 3 is effectively guaranteed, so that the bottom surface of the pressure block 34 can always fit the chip 10 below.

[0084] By setting the spherical structure 35 or the rotating seat 8, the adaptability of the pressure head assembly 3 to the pressure of the chip 10 below can be effectively guaranteed, especially the adaptability to the thickness change during the sintering process, which effectively ensures the stability of the force applied to the chip 10.

[0085] In this embodiment, by synchronously setting multiple groups of pressurizing mechanisms on the rotating shaft 14, it can be suitable for synchronous press-fitting of multiple chips 10; by two opposing groups of pressurizing devices, or the parallel setting of multiple pressure head assemblies 3 at the front end of the lever 2, two or even multiple columns of chips 10 can be press-fitted at the same time, which can greatly improve the efficiency of chip 10 mounting.

[0086] like Fig. 9 As shown, it is a rotation principle diagram of the cam 51, point o is the rotation center of the cam 51, ω is the angular velocity of the cam 51, and a rectangular coordinate system is established with point o as the origin. is the polar angle of any point on the profile curve, θ is the rotation angle of the cam 51 after time t, then θ=ω*t;

[0087] Line y = kx + b θ is the tangent line of the cam 51 after it rotates by θ, where k=tan(θ-π / 2), 0≤θ≤π;

[0088] The distance ρ of the tangent line from the center o of the cam 51 is the position of the pressure plate 4, and:

[0089]

[0090] Then the speed of the pressing plate 4 is:

[0091]

[0092] Assuming that the distance between the roller 21 and the rotating shaft 14 is R, the angular velocity of the lever 2 is According to the required ω', set b in the tangent line equation θ , thereby obtaining the required profile curve of the cam 51 to further enable the lever 2 to rotate first slowly, then quickly, and finally slowly, thereby effectively preventing the rotation of the lever 2 from causing an impact on the chip 10 on the substrate 12.

[0093] The movement of the cam 51 is regarded as uniform rotation, and the pressure plate 4 can make a desired movement by controlling the distance between a point on the contour curve of the cam 51 and the center of the cam 51 .

[0094] Assuming that the profile curve of the cam 51 push stroke is as follows, the movement speed of the pressing plate 4 is deduced and controlled. The specific process is as follows:

[0095]

[0096] Where ρ is the distance from the point on the profile curve to the cam center o, r is the base circle radius of the profile curve, and h is the lift of the cam during push stroke. is the polar angle of any point on the contour curve, and π is the total rotation angle of the push-stroke cam.

[0097] Taking the cam center o as the origin, establish a rectangular coordinate system, then:

[0098]

[0099] At this time, the slope of the tangent line at any point on the contour curve is:

[0100]

[0101] The angle corresponding to the tangent slope k is:

[0102]

[0103] That is, when the cam rotates by an angle θ, the corresponding position of the pressure plate 4 is a tangent line with a slope k.

[0104] By back-substituting θ, we can calculate the corresponding ρ, so the relative speed of the pressure plate 4 at any time is When r=h, the calculated movement speed of the pressing plate 4 is shown in Table 1. As can be seen from Table 1, the speed of the pressing plate 4 changes from slow to fast and then slow, which can make the lever 2 rotate slowly first, then fast, and finally slow. By making the contour curves of the cam return stroke and the push stroke symmetrical, the lever 2 can rotate slowly first, then fast, and then slow again during the lifting or falling process.

[0105] Table 1: Relationship between cam profile and pressing speed of pressure plate 4

[0106]

[0107] The pressurizing method of the pressurizing device in the chip mounting process of this embodiment includes the following steps:

[0108] Step 1: The cam 51 rotates to the position farthest from the pressure plate 4 in the axial direction, that is, the cam 51 applies force downward to the rear section of the lever 2 through the pressure plate 4, so that the lever 2 presents a state of high front and low rear under the pressure of the rear section, as shown in FIG. Fig.10 As shown, it is also convenient for placing or loading the front-end substrate 12, the chip 10, etc.;

[0109] At this time, the cam 51 applies force to the roller 21 on the top surface of the lever 2 in all the pressurizing mechanisms through the pressing plate 4, so that the rear sections of all the levers 2 are simultaneously subjected to the downward pressure of the pressing plate 4 and present a state where the front is higher and the back is lower;

[0110] At this time, the support plate 11 carrying the pressurizing mechanism can be located away from the substrate 12 carrying the chip 10. After adjusting the load 6 in the second step, the support plate 11 is moved back and forth relative to the base plate 1 to make the pressure head assembly 3 close to the chip 10.

[0111] Step 2: Adjust the weight of the load 6 at the end of each steel wire rope 61 according to the preset requirements. The weight of the load 6 is directly related to the pressure applied by the final pressure head assembly 3 to the chip 10;

[0112] The loads 6 in different pressurizing mechanisms can be set to different weights according to actual conditions.

[0113] Step 3: When the pressing head assembly 3 is located at the preset position above the corresponding chip 10, the cam 51 rotates, gradually reducing the distance by which it pushes the pressing plate 4 downward, and the pressing plate 4 gradually moves upward in contact with the outer wall of the cam 51. Under the continuous pulling of the load 6, the rear end of the lever 2 gradually swings upward along with the pressing plate 4, and the front end of the lever 2 swings downward accordingly and gradually moves downward toward the chip 10 below.

[0114] Step 4: until the cam 51 is at the closest position to the pressing plate 4 in the axial direction, the force applied downward by the pressing plate 4 to the lever 2 is minimal or even zero, and the lever 2 is continuously applied with an upward force by the rear end load 6 through the wire rope 61, so that the front end of the lever 2 is pressed downward on the chip 10 below through the pressing head assembly 3, so as to realize the stable pressing of the chip 10. Fig.11 As shown;

[0115] Step 5: When the pressurization is finished, the force applied by the pressing head assembly 3 to the chip 10 can be released by rotating the cam 51 as in the first step, thereby facilitating the unloading or removal of the chip 10 and the substrate 12 .

[0116] like Fig.12 As shown, two groups of pressurizing devices can be arranged facing each other on the same base plate 1, and the substrate 12 for placing the chip 10 is arranged between the two groups of pressurizing devices, and two columns of chips 10 corresponding to the two groups of pressurizing devices are arranged on the substrate 12. After the two groups of pressurizing devices move toward each other until the pressure head assembly 3 is located above the corresponding chip 10, the two columns of chips 10 are pressed and installed by the two groups of pressurizing devices at the same time.

[0117] like Fig.13As shown, the pressurizing device in this embodiment can also be used in heating or low temperature environments. For example, at the mounting pressurizing position 93 at the channel entrance 91 of the heating channel 9 at a temperature of 150-300°C, the chip 10 is pressed and fixed by the pressurizing device. Then, the pressurizing device and the chip 10 flow along the heating channel 9 through a conveyor belt or other conveying mechanism, maintaining a certain speed and performing intermittent motion until flowing out from the channel outlet 92, thereby realizing reliable pressing of the chip 10 in special environments such as heating or low temperature.

[0118] The present invention effectively ensures that the chip 10 is pressed continuously, evenly and stably, and is suitable for the synchronous pressing of multiple rows of chips 10, which greatly helps the use of chip 10 in mounting, and is particularly suitable for pressing the chip 10 in different occasions such as heating.

[0119] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A pressurizing device in a chip mounting process, characterized in that: The invention comprises a lever (2), a rotating shaft (14) being horizontally mounted on the lever (2), and the lever (2) swinging with the axial direction of the rotating shaft (14) as the center of a circle; the rear end of the lever (2) is hoisted by a steel wire rope (61), and the steel wire rope (61) is connected to a load (6) after passing through a pulley (62); a pressure head assembly (3) is mounted on the bottom surface of the front end of the lever (2), and a pressure block (34) at the bottom end of the pressure head assembly (3) applies a vertical downward force to a chip (10) below, thereby forming a pressure mechanism for the chip (10); a cam (51) is arranged above the lever (2) between the rotating shaft (14) and the steel wire rope (61), and as the cam (51) rotates, the cam (51) applies a downward force to the lever (2) below to release the downward pressure of the pressure head assembly (3) on the chip (10); a plurality of levers (2) are mounted on the rotating shaft (14) at intervals along the length direction, and the rear end of each lever (2) is hoisted and mounted. There are corresponding steel wire ropes (61), pulleys (62) and loads (6), and the front ends of the single levers (2) are all equipped with corresponding pressure head assemblies (3), so as to form a plurality of pressure mechanisms corresponding to the plurality of chips (10) one by one; a horizontal pressure plate (4) is arranged between the cam (51) and the lever (2), and the pressure plate (4) is arranged parallel to the rotating shaft (14), and the cam (51) rotates downward through the pressure plate (4) to synchronously act on the plurality of levers (2); it also includes a support plate (11), and the left and right sides of the support plate (11) are respectively equipped with side plates (13), and the two side plates (13) are jointly equipped with the rotating shaft (14); the two side plates (13) located behind the rotating shaft (14) are also jointly equipped with a camshaft (5), the cam (51) is sleeved on the camshaft (5), and the end of the camshaft (5) is connected with a motor (52); the two ends of the pressure plate (4) are elastically supported on the two side plates (13) below the camshaft (5).

2. A pressurizing device in a chip mounting process as claimed in claim 1, characterized in that: The side surfaces of the side plates (13) facing each other are respectively provided with accommodating cavities (15) inwardly concavely, a supporting block (41) is fixedly installed in the accommodating cavity (15), a vertical elastic member (42) is installed in the supporting block (41), the top of the elastic member (42) protrudes from the supporting block (41), the bottom end of the elastic member (42) is connected to the bottom end of the pressing plate (4), and the two groups of elastic members (42) jointly support the pressing plate (4) from both ends.

3. A pressurizing device in a chip mounting process as claimed in claim 2, characterized in that: A rear bracket (7) is installed at intervals on the support plate (11) located behind the side plate (13), a crossbeam is installed between the two rear brackets (7), and hanging brackets (63) corresponding to the pulleys (62) are installed at intervals along the length direction on the crossbeam, and the pulleys (62) are rotatably installed at the bottom ends of the hanging brackets (63).

4. The pressurizing device in the chip mounting process according to claim 1, characterized in that: The bottom surface of the support plate (11) is mounted with a bottom plate (1), and a guide rail is mounted on the bottom plate (1) along the front-rear direction, the guide rail is matched with the bottom surface of the support plate (11), and the support plate (11) moves forward and backward relative to the bottom plate (1) along the guide rail under the drive of an external power; the bottom plate (1) located in front of the support plate (11) is mounted with a guide rail along the left-right direction, and a base plate (12) is mounted on the guide rail, and a plurality of chips (10) corresponding to the pressure mechanism are placed on the base plate (12) along the left-right direction, and the base plate (12) moves left-right relative to the bottom plate (1) along the guide rail under the drive of an external power.

5. The pressurizing device in the chip mounting process according to claim 1, characterized in that: The top surface of each of the single levers (2) is provided with supports (22) spaced apart on the left and right sides, and a roller (21) is rotatably mounted between the two supports (22); the roller (21) is located below the pressure plate (4), and when the pressure plate (4) moves downward, it applies forces to the upper part of the circumferential wall of the roller (21) in opposite directions.

6. The pressurizing device in the chip mounting process according to claim 1, characterized in that: A set of pressure head assemblies (3) is installed at the lower part of the front end of the lever (2), or a plurality of sets of pressure head assemblies (3) are installed at intervals along the length direction of the lever (2); the structure of a single set of pressure head assemblies (3) is as follows: it includes a support shell (32), the top of the support shell (32) is inserted into the lever (2), and the latch (31) passes through the upper part of the support shell (32) and the lever (2) to fix them relatively; a small spring (33) is installed in the inner cavity of the support shell (32), and the bottom end of the small spring (33) is connected to a pressure block (34), and the pressure block (34) extends downward from the support shell (32); the bottom end of the pressure block (34) is set as an outwardly convex spherical structure (35).

7. The pressurizing device in the chip mounting process according to claim 1, characterized in that: The front end of the lever (2) is rotatably mounted with a rotating seat (8), the rotating seat (8) being rotatably mounted relative to the lever (2) via an axis in the left and right horizontal directions, a group of pressure head assemblies (3) being mounted on the bottom surface of the rotating seat (8), or a plurality of groups of pressure head assemblies (3) being mounted on the bottom surface of the rotating seat (8) at intervals along the front-to-back direction; a pressure block (34) is mounted at the center of the bottom end of each group of pressure head assemblies (3), and the bottom surface of the pressure block (34) is a flat surface or an outward convex spherical surface.

8. A pressurizing method of a pressurizing device in a chip mounting process according to claim 1, characterized in that: The steps include: The cam (51) rotates to a position farthest from the pressure plate (4) in the axial direction, i.e., the cam (51) applies force downward to the rear section of the lever (2) through the pressure plate (4), so that the lever (2) presents a state where the front is higher and the rear is lower under the downward pressure of the rear section; The weight of the load (6) at the end of each steel wire rope (61) is adjusted according to preset requirements, and the weight of the load (6) is directly related to the pressure applied by the final pressure head assembly (3) to the chip (10); When the pressure head assembly (3) is located at a preset position above the corresponding chip (10), the cam (51) rotates, gradually reducing the distance by which it pushes the pressure plate (4) downward, and the pressure plate (4) gradually moves upward in contact with the outer wall of the cam (51). Under the continuous pulling of the load (6), the rear end of the lever (2) gradually swings upward along with the pressure plate (4), and the front end of the lever (2) swings downward accordingly, gradually moving downward toward the chip (10) below. Until the cam (51) is at the position closest to the pressure plate (4) axially, the force applied downward by the pressure plate (4) to the lever (2) is minimal or even zero, and the lever (2) is continuously applied with an upward force by the rear end load (6) via the wire rope (61), so that the front end of the lever (2) applies downward pressure to the chip (10) below via the pressure head assembly (3), thereby achieving stable press-fitting of the chip (10).

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