Hot pressing reflow device and method for welding fine-pitch LED chips

Abstract

In a hot press reflow soldering device and method for soldering fine-pitch LED chips, an upper hot press assembly and a lower hot press assembly are arranged relative to each other and spaced apart. The upper hot press assembly is arranged above an upper flexible conveyor belt, while the lower hot press assembly is arranged below the lower flexible conveyor belt. An upper flexible conveyor belt control device is connected to the upper flexible conveyor belt to control the upper flexible conveyor belt's cyclic rotation. A lower flexible conveyor belt control device is connected to the lower flexible conveyor belt to control the lower flexible conveyor belt's cyclic rotation. The upper and lower flexible conveyor belts are arranged relative to each other and spaced apart. The upper and lower flexible conveyor belts jointly clamp the soldered object during movement, allowing the soldered object to pass through the space between the upper and lower hot press assemblies. This allows direct heat conduction between the upper and lower surfaces of the soldered object, thereby improving heat conduction efficiency during soldering, shortening the soldering heating time, and increasing the soldering yield rate.

Description

Technical Field

[0001] The present invention relates to the field of microelectronics and semiconductor chip packaging technology and equipment, and specifically to a device and method for packaging or welding micro-pitch LED chips, and more particularly to a hot press reflow device and method for packaging or welding micro-pitch LED chips. Background Art

[0002] With the development of micro-photoelectric display technology in recent years, most LED chips used in micro-pitch direct display light sources adopt flip-chip packaging, using solder paste, solder glue and flux glue or chip electrode tinning plus flux soldering material application method, using reflow heating process to make it melt and then weld to achieve metallurgical connection between the electrodes of LED chip and COB or COG board, so as to achieve the purpose of electrical and thermal conductivity.

[0003] Because fine-pitch LED chips are typically small, typically 0408 chips, or even 0203 or 0102 chips. A 0408 chip measures 4 mil x 8 mil; a 0203 chip measures 2 mil x 3 mil; and a 0102 chip measures 1 mil x 2 mil. A mil represents one thousandth of an inch, and thicknesses are all within the micron range. In traditional SMT reflow soldering, the soldered object is typically unconstrained during the reflow process. Heat is transferred through the underlying hot plate, either through conduction, convection, or radiation. This causes the tiny chip to float above the solder, resulting in uneven soldering and poor lighting performance. This heat transfer process is detrimental to flip-chip LED chip soldering because the energy from the underlying hot plate must be transferred through the COB (Chip On Board) or COG (Chip On Glass) substrate to the flip-chip LED chip solder joints. This results in inefficient heat transfer and prevents rapid melting of the solder joints. The uniformity and stability of the heat field generated by convection or radiation conduction are also highly correlated with the heat source and conduction method. In micro-pitch LED chip soldering, the micron-level solder joint spacing amplifies the impact of the uniformity and stability of the heat field on the soldering quality. Even slight fluctuations and uneven distribution of the heat field can lead to differences in soldering temperature and, consequently, soldering quality. The temperature range that LED chip soldering can withstand also needs to be within a certain range, so this soldering method can result in a high soldering defect rate.

[0004] Traditional reflow soldering processes are unable to meet the requirements of micro-pitch LED flip-chip soldering, resulting in industry technical pain points such as low yield and high rework costs. Due to the small soldering area and the tens of thousands of solder joints integrated into a micro-pitch display unit, traditional reflow soldering equipment cannot achieve reliable soldering results for each of these densely packed solder joints. This can easily lead to cold solder joints or poor soldering. During the subsequent processing and use of the micro-pitch display unit, the influence of ambient operating heat energy can cause thermal stress changes within the LED display unit, leading to solder joint detachment and failure. There is an urgent need to improve traditional reflow soldering equipment and methods to enhance the soldering quality and efficiency of micro-pitch LED flip-chips.

[0005] Chinese patent application publication number CN112333932A proposes a multi-head hot-press reflow device and its operating method, and proposes a constrained reflow process for micro-pitch LED flip-chip COB or COG assembly using multiple hot-pressing devices operating simultaneously. However, this device is complex and operates intermittently, resulting in low efficiency and inconsistent soldering results due to uneven temperatures among multiple sets of hot-pressing plates.

[0006] In this application, micro-pitch LED chips refer to mini or micro LED chips with chip size less than 100 microns (width) × 200 microns (length) and LED light point spacing less than 0.9 microns. Summary of the Invention

[0007] The technical solution of the present invention overcomes the shortcomings of the prior art and designs a welding device and method that can clamp the welded body up and down during movement, so that the welded body can directly and evenly conduct double-sided heat conduction, so that the upper and lower surfaces of the welded body can both directly and evenly conduct heat, thereby improving the heat conduction efficiency during welding, shortening the welding heating time, and improving the welding yield rate; so that the various welding points on the welded body can be heated more evenly, the chip flatness is better, the consistency is better, and the welding yield rate can be greatly improved; and the welded body can be automatically and periodically fed in sequence, avoiding the defect that traditional double-sided hot pressing must be interrupted, and can greatly improve production efficiency.

[0008] In the present application, the technical solution to solve the above-mentioned technical problems is a hot press reflow soldering device for micro-pitch LED chip welding, comprising a reflow soldering device main body, an upper flexible conveyor belt control device, an upper flexible conveyor belt, an upper hot pressing assembly, a lower flexible conveyor belt control device, a lower flexible conveyor belt, and a lower hot pressing assembly; the upper hot pressing assembly and the lower hot pressing assembly are respectively fixedly connected to the reflow soldering device main body; the upper hot pressing assembly and the lower hot pressing assembly are arranged relative to each other and at a distance; the upper hot pressing assembly is arranged above the upper flexible conveyor belt; the lower hot pressing assembly is arranged below the lower flexible conveyor belt; the upper flexible conveyor belt control device is connected to the upper flexible conveyor belt to control the cyclic rotation of the upper flexible conveyor belt; the lower flexible conveyor belt control device is connected to the lower flexible conveyor belt to control the cyclic rotation of the lower flexible conveyor belt; the upper flexible conveyor belt and the lower flexible conveyor belt are arranged relative to each other and at a distance; the upper flexible conveyor belt and the lower flexible conveyor belt jointly clamp the welded body during movement, so that the welded body moves through the space between the upper hot pressing assembly and the lower hot pressing assembly.

[0009] The distance between the upper hot pressing assembly and the lower hot pressing assembly is adjustable; or the distance between the upper hot pressing assembly and the lower hot pressing assembly is set to be less than 10 mm.

[0010] The upper hot pressing assembly includes an upper hot pressing temperature control device and an upper hot pressing body; the upper hot pressing temperature control device is connected to the upper hot pressing body, and the upper hot pressing temperature control device outputs heat energy to the upper hot pressing body and controls the temperature of the upper hot pressing body; the temperature of the upper hot pressing assembly is set between 50-500℃.

[0011] The lower hot pressing assembly includes a lower hot pressing temperature control device and a lower hot pressing body; the lower hot pressing temperature control device is connected to the lower hot pressing body, and the lower hot pressing temperature control device outputs heat energy to the lower hot pressing body and controls the temperature of the lower hot pressing body; the temperature of the lower hot pressing assembly is set between 50-500℃.

[0012] The upper hot pressing assembly also includes an upper hot pressing pressure control device; the upper hot pressing pressure control device is connected to the upper hot pressing body, and the upper hot pressing pressure control device outputs a downward force to the upper hot pressing body, and the downward pressure generated by this force is in the range of 0.5-5MPa; the upper hot pressing pressure control device controls the distance between the upper hot pressing body and the lower hot pressing body.

[0013] The lower hot pressing assembly also includes a lower hot pressing pressure control device; the lower hot pressing pressure control device is connected to the lower hot pressing body, and the lower hot pressing pressure control device outputs an upward force to the lower hot pressing body, and the upward pressure generated by the force is in the range of 0.5-5MPa; the lower hot pressing pressure control device controls the distance between the lower hot pressing body and the upper hot pressing body; or the lower hot pressing pressure control device and the upper hot pressing pressure control device jointly control the distance between the lower hot pressing body and the upper hot pressing body.

[0014] The upper hot pressing body is a flat hot pressing plate; the lower hot pressing body is a flat hot pressing plate;

[0015] The upper hot pressing pressure control device adjusts the distance between the upper hot pressing assembly and the lower hot pressing assembly, and presses the upper flexible conveyor belt downward so that when the upper flexible conveyor belt passes through the distance between the upper hot pressing assembly and the lower hot pressing assembly, the upper flexible conveyor belt has an angle of less than or equal to 5 degrees relative to the horizontal direction. o Angle.

[0016] The hot press reflow soldering device for micro-pitch LED chip welding also includes two first thickness gauges and two second thickness gauges; the two ends of the upper hot press assembly on the opposite side of the lower hot press assembly are respectively connected by a first thickness gauge; the vertical spacing between one side of the upper hot press assembly and the corresponding side of the lower hot press assembly is called the first spacing; the two first thickness gauges are used to adjust the size of the first spacing and limit the thickness of the first spacing; the two ends of the upper hot press assembly on the other opposite side of the lower hot press assembly are respectively connected by a second thickness gauge; the vertical spacing between the other side of the upper hot press assembly and the corresponding side of the lower hot press assembly is called the second spacing; the two second thickness gauges are used to adjust the size of the second spacing and limit the thickness of the second spacing; the adjustment range of the first spacing and the second spacing is 0.100-10.000mm.

[0017] The width of the upper flexible conveyor belt and the lower flexible conveyor belt is set between 100-1000 mm; the thickness of the upper flexible conveyor belt and the lower flexible conveyor belt is set between 1-3 mm.

[0018] The upper flexible conveyor belt control device includes an upper flexible conveyor belt driving roller, an upper flexible conveyor belt tensioning roller and an upper flexible conveyor belt tensioning device; the two ends of the upper flexible conveyor belt closed into a ring are respectively connected to the upper flexible conveyor belt driving roller and the upper flexible conveyor belt tensioning roller; when the upper flexible conveyor belt driving roller is driven to rotate, the upper flexible conveyor belt is driven to move; the upper flexible conveyor belt tensioning device controls the upper flexible conveyor belt tensioning roller, and the upper flexible conveyor belt tensioning roller adjusts the tensioning state of the upper flexible conveyor belt; the lower flexible conveyor belt control device includes a lower flexible conveyor belt driving roller, a lower flexible conveyor belt tensioning roller and a lower flexible conveyor belt tensioning device; the two ends of the lower flexible conveyor belt closed into a ring are respectively connected to the lower flexible conveyor belt driving roller and the lower flexible conveyor belt tensioning roller; when the lower flexible conveyor belt driving roller is driven to rotate, the lower flexible conveyor belt is driven to move; the lower flexible conveyor belt tensioning device controls the lower flexible conveyor belt tensioning roller, and the lower flexible conveyor belt tensioning roller adjusts the tensioning state of the lower flexible conveyor belt.

[0019] The hot press reflow soldering device for micro-pitch LED chip welding is also provided with an upper flexible conveyor belt drive roller heating and temperature control device and an upper flexible conveyor belt tensioning roller heating and temperature control device; the upper flexible conveyor belt drive roller heating and temperature control device outputs heat energy to the upper flexible conveyor belt drive roller and controls the temperature of the upper flexible conveyor belt drive roller; the upper flexible conveyor belt tensioning roller heating and temperature control device outputs heat energy to the upper flexible conveyor belt tensioning roller and controls the temperature of the upper flexible conveyor belt tensioning roller; the two ends of the upper flexible conveyor belt are respectively connected to the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller, and obtain heat energy from the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller.

[0020] The hot press reflow soldering device for micro-pitch LED chip welding is also provided with a lower flexible conveyor belt drive roller heating and temperature control device and a lower flexible conveyor belt tensioning roller heating and temperature control device; the lower flexible conveyor belt drive roller heating and temperature control device outputs heat energy to the lower flexible conveyor belt drive roller and controls the temperature of the lower flexible conveyor belt drive roller; the lower flexible conveyor belt tensioning roller heating and temperature control device outputs heat energy to the lower flexible conveyor belt tensioning roller and controls the temperature of the lower flexible conveyor belt tensioning roller; the two ends of the lower flexible conveyor belt are respectively connected to the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller, and obtain heat energy from the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller.

[0021] The temperatures of the upper flexible conveyor belt and the lower flexible conveyor belt are respectively set between 50-500°C.

[0022] In the present application, the technical solution to the above-mentioned technical problems can also be a hot press reflow soldering method for micro-pitch LED chip welding, including step A: arranging an upper flexible conveyor belt and a lower flexible conveyor belt that rotate continuously in the same direction relative to each other and with a spacing; step B: arranging an upper hot press assembly and a lower hot press assembly relative to each other and with a spacing; the upper hot press assembly is arranged above the upper flexible conveyor belt; the lower hot press assembly is arranged below the lower flexible conveyor belt; step C: the welded body is clamped between the upper flexible conveyor belt and the lower flexible conveyor belt during movement, and passes through the space between the upper hot press assembly and the lower hot press assembly to perform reflow soldering that can directly conduct heat on both sides by hot pressing.

[0023] In step B: the distance between the upper hot pressing assembly and the lower hot pressing assembly is adjustable; or the distance between the upper hot pressing assembly and the lower hot pressing assembly is set to be less than 10 mm.

[0024] In step B: the upper hot pressing assembly includes an upper hot pressing temperature control device and an upper hot pressing body; the upper hot pressing temperature control device is connected to the upper hot pressing body, the upper hot pressing temperature control device outputs heat energy to the upper hot pressing body and controls the temperature of the upper hot pressing body; the temperature of the upper hot pressing assembly is set between 50-500℃.

[0025] In step B: the lower hot pressing assembly includes a lower hot pressing temperature control device and a lower hot pressing body; the lower hot pressing temperature control device is connected to the lower hot pressing body, the lower hot pressing temperature control device outputs heat energy to the lower hot pressing body and controls the temperature of the lower hot pressing body; the temperature of the lower hot pressing assembly is set between 50-500℃.

[0026] The upper hot pressing assembly also includes an upper hot pressing pressure control device; the upper hot pressing pressure control device is connected to the upper hot pressing body, the upper hot pressing pressure control device outputs a downward force to the upper hot pressing body, and the upper hot pressing pressure control device controls the distance between the upper hot pressing body and the lower hot pressing body.

[0027] The lower hot pressing assembly also includes a lower hot pressing pressure control device; the lower hot pressing pressure control device is connected to the lower hot pressing body, and the lower hot pressing pressure control device outputs an upward force to the lower hot pressing body and controls the distance between the lower hot pressing body and the upper hot pressing body; or the lower hot pressing pressure control device and the upper hot pressing pressure control device jointly control the distance between the lower hot pressing body and the upper hot pressing body.

[0028] In step B: it also includes the step of using a first thickness gauge and a second thickness gauge to adjust the distance between the upper hot pressing assembly and the lower hot pressing assembly; the two ends of the upper hot pressing assembly on the opposite side of the lower hot pressing assembly are respectively connected by a first thickness gauge; the vertical distance between one side of the upper hot pressing assembly and the corresponding side of the lower hot pressing assembly is called the first distance; the two first thickness gauges are used to adjust the size of the first distance and limit the thickness of the first distance; the two ends of the upper hot pressing assembly on the other side of the lower hot pressing assembly are respectively connected by a second thickness gauge; the vertical distance between the other side of the upper hot pressing assembly and the corresponding other side of the lower hot pressing assembly is called the second distance; the two second thickness gauges are used to adjust the size of the second distance and limit the thickness of the second distance; the adjustment range of the first distance and the second distance is 0.100-10.000mm.

[0029] In step A, the width of the upper flexible conveyor belt and the lower flexible conveyor belt is set between 50-1000 mm; the thickness of the upper flexible conveyor belt and the lower flexible conveyor belt is set between 1-3 mm.

[0030] In step A, it also includes the step of heating the upper flexible conveyor belt using the upper flexible conveyor belt drive roller heating temperature control device and the upper flexible conveyor belt tensioning roller heating temperature control device; the upper flexible conveyor belt drive roller heating temperature control device outputs heat energy to the upper flexible conveyor belt drive roller and controls the temperature of the upper flexible conveyor belt drive roller; the upper flexible conveyor belt tensioning roller heating temperature control device outputs heat energy to the upper flexible conveyor belt tensioning roller and controls the temperature of the upper flexible conveyor belt tensioning roller; the two ends of the upper flexible conveyor belt closed into a ring are respectively connected to the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller, and obtain heat energy from the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller; the temperature of the upper flexible conveyor belt is set between 50-500℃.

[0031] In step A, it also includes the step of heating the lower flexible conveyor belt using the lower flexible conveyor belt drive roller heating temperature control device and the lower flexible conveyor belt tensioning roller heating temperature control device; the lower flexible conveyor belt drive roller heating temperature control device outputs heat energy to the lower flexible conveyor belt drive roller and controls the temperature of the lower flexible conveyor belt drive roller; the lower flexible conveyor belt tensioning roller heating temperature control device outputs heat energy to the lower flexible conveyor belt tensioning roller and controls the temperature of the lower flexible conveyor belt tensioning roller; the two ends of the lower flexible conveyor belt closed into a ring are respectively connected to the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller to obtain heat energy from the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller; the temperature of the lower flexible conveyor belt is set between 50-500℃.

[0032] Compared with the prior art, one of the beneficial effects of the present invention is that the upper and lower flexible conveyor belts and the upper and lower hot pressing components cooperate with each other to form an upper and lower clamping of the welded body during movement, so that the upper and lower surfaces of the welded body can directly conduct heat, thereby improving the heat conduction efficiency during welding, allowing the upper and lower surfaces of the welded body to be heated at the same time, shortening the welding heating time, and improving the welding yield rate.

[0033] Compared with the prior art, the second beneficial effect of the present invention is that the welded body is clamped in uniform motion and contacts the upper and lower hot pressing components while passing through the welding heating zone. The uniform motion method can further shorten the welding heating time and improve the welding yield.

[0034] Compared with the prior art, the third beneficial effect of the present invention is: the main body to be welded is clamped and contacts the upper and lower hot pressing assemblies in uniform motion; the upper and lower hot pressing assemblies and the upper and lower flexible conveyor belts are all in a state of preheating to the target welding temperature, and the upper and lower hot pressing assemblies and the upper and lower flexible conveyor belts are in a reflow soldering background as a whole. The heating by radiation and convection also maintains the temperature of the entire welding atmosphere and plays a role in temperature balance and stability. The movement and direct contact heat conduction method enables each solder point on the main body to be welded to be in a more uniform heat conduction environment, each solder point is heated more evenly, the chip flatness is better, the consistency is better, and the welding yield can be greatly improved.

[0035] Compared with the existing technology, the present invention has a fourth beneficial effect: the welded body is clamped by the upper and lower flexible conveyor belts and can be automatically and periodically fed into the space between the upper and lower hot pressing assemblies for welding without interruption, which can significantly improve production efficiency. This avoids the disadvantage of traditional double-sided hot pressing that requires interruption. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 2 is a schematic cross-sectional view of a preferred embodiment 1 of a hot press reflow soldering device for soldering fine-pitch LED chips;

[0037] Figure 2 1 is a top view schematic diagram of a preferred embodiment 1 of a hot press reflow soldering device for soldering fine-pitch LED chips;

[0038] Figure 3 This is a schematic cross-sectional view of a preferred embodiment 2 of a hot-press reflow soldering device for soldering fine-pitch LED chips;

[0039] Figure 4 1 is a top view schematic diagram of a preferred embodiment 2 of a hot press reflow soldering device for soldering fine-pitch LED chips;

[0040] Figure 5 This is a schematic cross-sectional view of a third preferred embodiment of a hot-press reflow soldering device for soldering fine-pitch LED chips;

[0041] Figure 6 1 is a top view schematic diagram of a preferred embodiment 3 of a hot press reflow soldering device for soldering fine-pitch LED chips. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the accompanying drawings.

[0043] like Figures 1 to 4 In the embodiment of a hot press reflow soldering device for soldering fine-pitch LED chips, the device comprises an upper flexible conveyor belt control device, an upper flexible conveyor belt 12, an upper hot press assembly 14, a lower flexible conveyor belt control device, a lower flexible conveyor belt 13, and a lower hot press assembly 15; the upper hot press assembly 14 and the lower hot press assembly 15 are respectively fixedly connected to the reflow soldering device body; the upper hot press assembly 14 and the lower hot press assembly 15 are arranged opposite to each other and at a distance; the upper hot press assembly 14 is arranged above the upper flexible conveyor belt 12; the lower hot press assembly 15 is arranged below the lower flexible conveyor belt 13; the upper flexible conveyor belt control device is connected to the upper flexible conveyor belt 12 to control the cyclic rotation of the upper flexible conveyor belt 12; the lower flexible conveyor belt control device is connected to the lower flexible conveyor belt 13 to control the cyclic rotation of the lower flexible conveyor belt 13; the upper flexible conveyor belt 12 and the lower flexible conveyor belt 13 are arranged opposite to each other and at a distance; the upper flexible conveyor belt and the lower flexible conveyor belt jointly clamp the soldered body during movement, so that the soldered body passes through the space between the upper hot press assembly 14 and the lower hot press assembly 15. Even if the soldered body is clamped and contacts the upper flexible conveyor belt 12 and the lower flexible conveyor belt 13 in the same direction of movement, it passes through the space between the upper hot pressing assembly 14 and the lower hot pressing assembly 15. Figures 1 to 2 Not displayed in Figure 3 and Figure 4 The first main body bracket 25 and the second main body bracket 26 are part of the main body of the reflow soldering device.

[0044] like Figure 1 and Figure 3 In the illustrated embodiment, the upper hot press assembly 14 contacts and abuts the upper flexible conveyor belt 12 to form an upper heating zone; the lower hot press assembly 15 contacts and abuts the lower flexible conveyor belt 13 to form a lower heating zone; the upper heating zone and the lower heating zone face each other to form a hot press reflow zone. The device utilizes direct contact conduction heating to provide controlled contact heating of the soldered object, allowing the flip chip to quickly obtain the required thermal energy for soldering or curing, and forming effective solder joints or adhesive connections. The upper flexible conveyor belt 12, upper hot press assembly 14, lower flexible conveyor belt 13, lower hot press assembly 15, and soldered object can be exposed to a conventional reflow soldering environment. That is, the hot press reflow soldering apparatus for fine-pitch LED chips in this application can inherit the soldering temperature environment of conventional reflow soldering. However, in some cases, the upper flexible conveyor belt 12, upper hot press assembly 14, lower flexible conveyor belt 13, lower hot press assembly 15, and soldered object need not necessarily be exposed to a conventional reflow soldering environment.

[0045] like Figure 1 and Figure 3 In the illustrated embodiment, the subject being soldered is a fine-pitch LED chip. During soldering, the fine-pitch LED chip comprises an LED chip 99, solder 92, and a substrate 91. Solder 92 is applied between the LED chip 99 and the substrate 91. The upper surface of the LED chip 99 contacts the lower surface of the upper flexible conveyor belt 12, while the lower bottom surface of the substrate 91 contacts the upper surface of the lower flexible conveyor belt 13. In other words, the subject being soldered is clamped between the lower surface of the upper flexible conveyor belt 12 and the upper surface of the lower flexible conveyor belt 13. The upper and lower flexible conveyor belts 12 and 13 jointly clamp the subject being soldered during movement, so that as the subject being soldered passes through the space between the upper hot press assembly 14 and the lower hot press assembly 15, the upper hot press assembly 14 contacts the upper surface of the upper flexible conveyor belt 12. Most of the heat from the upper hot press assembly 14 is directly transferred to the upper flexible conveyor belt 12, and the heat from the upper flexible conveyor belt 12 is directly transferred to the upper surface of the component being soldered that is in contact with the upper flexible conveyor belt. Of course, a small portion of the heat on the upper hot pressing assembly 14 can also be transferred to the welded body by convection or radiation. The substrate 91 includes a COB board or a COG board.

[0046] Direct contact heat conduction has high heat transfer efficiency, especially in the welding of fine-pitch LED chips. Each solder joint is very small, and the heat conduction method can quickly bring the solder joint to the melting temperature. Due to this heat conduction method, as long as the temperature uniformity on the upper hot pressing component 14 is good, the uniformity of the temperature of each solder joint can be controlled, which greatly improves the welding consistency performance of high-density fine-pitch LED chips and greatly reduces the defective rate of high-density fine-pitch LED chips. The upper hot pressing component 14 in this application can be a whole unit or a whole unit composed of multiple components spliced ​​together.

[0047] In the prior art, when a reflow soldering device with a single-sided hot plate is used to solder micro-pitch LED chips, only single-sided heating or non-contact double-sided heating is usually possible. Even if double-sided heating is available, it is intermittent double-sided heating, and automatic circulation and continuous soldering cannot be achieved. In the prior art, a single-sided hot plate heating method is used, and the defective rate of micro-pitch LED chips due to soldering is about 0.1%. After soldering using the soldering device in the present application, the defective rate of micro-pitch LED chips due to soldering is reduced to about 0.01%. The production efficiency of intermittent double-sided heating is usually 0.2 square meters to 0.5 square meters per hour; the circulation speed of the upper and lower flexible conveyor belts 12 in the present application can be flexibly adjusted according to the soldering requirements. The production efficiency is far greater than that of intermittent double-sided heating.

[0048] like Figures 1 to 6 In the embodiment shown, the travel speeds of the upper flexible conveyor belt 12 and the lower flexible conveyor belt 13 can be adjusted according to the welding requirements. On the one hand, the time for the welded body to undergo welding can be flexibly set; and the time can be related to the temperature of the upper flexible conveyor belt 12 and the lower flexible conveyor belt 13 and the upper hot pressing assembly 14 and the lower hot pressing assembly 15; so that the welding temperature and the welding speed can be adjusted to the optimal state, maximizing the production efficiency.

[0049] like Figures 1 to 6 In the illustrated embodiment, the temperatures of the upper and lower hot press assemblies can each be set between 50°C and 500°C. This temperature setting can accommodate most soldering requirements; the upper and lower hot press assemblies can be set independently of each other, meaning they can be set to different temperatures to suit the soldering locations they contact. During soldering of a fine-pitch LED chip comprising an LED chip 99, solder 92, and substrate 91, the upper hot press assembly 14 contacts the upper flexible conveyor belt 12, which in turn contacts the LED chip 99. The temperature of the upper hot press assembly 14 can be set based on the soldering temperature requirements of the LED chip 99. The temperature of the lower hot press assembly 15 can also be set based on the soldering temperature requirements of the substrate 91. The temperatures of the upper and lower hot press assemblies 14, 15 can be set in different temperature ranges, or they can be set within the same temperature range.

[0050] like Figures 1 to 6In the illustrated embodiment, the spacing between the upper hot press assembly 14 and the lower hot press assembly 15 is adjustable; alternatively, the spacing between the upper hot press assembly 14 and the lower hot press assembly 15 is set to less than 10 mm. The spacing between the upper hot press assembly 14 and the lower hot press assembly 15 can be adjusted based on the overall thickness of the body being welded. In the welding of fine-pitch LED chips, the spacing between the upper hot press assembly 14 and the lower hot press assembly 15 can be set to less than 10 mm to accommodate different substrate thicknesses and fine-pitch LED chip thicknesses. Typically, the thickness of a fine-pitch LED chip is between 0.1 mm and 0.005 mm, and the substrate thickness is between 0.1 and 1 mm. The spacing between the upper hot pressing assembly 14 and the lower hot pressing assembly 15 can be adjusted or set to ensure that the upper surface of the welded body can contact the lower surface of the upper flexible conveyor belt 12, and the lower surface of the welded body can contact the upper surface of the lower flexible conveyor belt 13, thereby ensuring that the welded body can directly contact the upper flexible conveyor belt 12, the upper hot pressing assembly 14, the lower flexible conveyor belt 13, and the lower hot pressing assembly 15 for heat conduction, thereby ensuring heat conduction efficiency. When the upper surface of the welded body contacts the lower surface of the upper flexible conveyor belt, the pressure range of the upper surface of the welded body is 0.5-5MPa; when the lower surface of the welded body contacts the upper surface of the lower flexible conveyor belt, the pressure range of the lower surface of the welded body is 0.5-5MPa.

[0051] like Figure 1 、 Figure 3 and Figure 5 In the embodiment shown, after adjusting the distance between the upper hot pressing assembly 14 and the lower hot pressing assembly 15, the upper flexible conveyor belt 12 is pressed downward, so that when the upper flexible conveyor belt 12 passes through the distance between the upper hot pressing assembly 14 and the lower hot pressing assembly 15, the upper flexible conveyor belt 12 is about 5 meters in height relative to the horizontal direction. o Angle.

[0052] like Figure 1 and Figure 3In the illustrated embodiment, the upper hot-press assembly 14 includes an upper hot-press temperature control device and an upper hot-press body 141; the upper hot-press temperature control device is not shown in the figure; the upper hot-press temperature control device is connected to the upper hot-press body 141, outputs heat energy to the upper hot-press body 141, and controls the temperature of the upper hot-press body 141; the lower hot-press assembly 15 includes a lower hot-press temperature control device and a lower hot-press body 151; the lower hot-press temperature control device is not shown in the figure; the lower hot-press temperature control device is connected to the lower hot-press body 151, outputs heat energy to the lower hot-press body 151, and controls the temperature of the lower hot-press body 151. The temperature of the upper hot-press assembly 14 can be controlled by the upper hot-press temperature control device. The temperature of the lower hot-press assembly 15 can be controlled by the lower hot-press temperature control device. The temperatures of the upper hot-press assembly 14 and the lower hot-press assembly 15 can be independently controlled by corresponding heating and temperature control devices. The upper hot pressing temperature control device and the lower hot pressing temperature control device include various heating control devices in the prior art, such as an electromagnetic heating temperature control device, a hot oil temperature control device, and the like.

[0053] like Figure 1 and Figure 3 In the illustrated embodiment, the upper hot pressing assembly 14 further includes an upper hot pressing pressure control device 142; the upper hot pressing pressure control device 142 is connected to the upper hot pressing body 141, and the upper hot pressing pressure control device 142 outputs a downward force to the upper hot pressing body, thereby controlling the distance between the upper hot pressing body 141 and the lower hot pressing body. The upper hot pressing pressure control device 142 can control the magnitude of the downward force exerted by the upper hot pressing body 141, thereby also controlling the distance between the upper hot pressing body 141 and the lower hot pressing body. During the welding of a micro-pitch LED chip comprising an LED chip 99, solder 92, and a substrate 91, the pressures that the LED chip 99 and the substrate 91 can withstand are different, and adaptive adjustments can be made based on the pressure tolerance of the materials on the upper and lower surfaces of the different bodies being welded.

[0054] like Figure 1 and Figure 3In the illustrated embodiment, the lower hot press assembly 15 further includes a lower hot press pressure control device 152. The lower hot press pressure control device 152 is connected to the lower hot press body 151 and outputs an upward force to the lower hot press body 151, thereby controlling the distance between the lower hot press body 151 and the upper hot press body 141. Alternatively, the lower hot press pressure control device 152 and the upper hot press pressure control device 142 jointly control the distance between the lower hot press body 151 and the upper hot press body 141. The lower hot press pressure control device 152 outputs an upward force to the lower hot press body 151, thereby controlling the distance between the lower hot press body 151 and the upper hot press body 141. During soldering of a fine-pitch LED chip comprising an LED chip 99, solder 92, and substrate 91, the pressures that the LED chip 99 and substrate 91 can withstand vary, and this pressure can be adaptively adjusted based on the pressure tolerance of the upper and lower surfaces of the different soldered materials. Of course, the lower hot press pressure control device 152 and the upper hot press pressure control device 142 can jointly control the distance between the lower hot press body and the upper hot press body, adjusting the distance to the position that is suitable for the upper and lower surfaces of the welded body, so that the upper and lower surfaces of the welded body receive just the right amount of force, ensuring that the clamping state generates contact heat conduction and that the clamping force is appropriate to avoid damaging the components of the welded body. The upper hot press pressure control device 142 and the lower hot press pressure control device 152 can adjust the output pressure separately; the upper hot press pressure control device 142 and the lower hot press pressure control device 152 can also adjust the output pressure to be consistent at the same time.

[0055] like Figure 1 and Figure 3In the illustrated embodiment, two first thickness gauges 181 and two second thickness gauges 182 are further included; the two ends of the opposite side of the upper hot pressing assembly 14 and the lower hot pressing assembly 15 are respectively connected by a first thickness gauge 181; the vertical distance between one side of the upper hot pressing assembly 14 and the corresponding side of the lower hot pressing assembly 15 is called the first distance; the two first thickness gauges 181 are used to adjust the size of the first distance and limit the thickness of the first distance. The two ends of the opposite side of the upper hot pressing assembly 14 and the lower hot pressing assembly 15 are respectively connected by a second thickness gauge 182; the vertical distance between the other side of the upper hot pressing assembly 14 and the corresponding side of the lower hot pressing assembly 15 is called the second distance; the two second thickness gauges 182 are used to adjust the size of the second distance and limit the thickness of the second distance; the adjustment range of the first distance and the second distance is 0.100-10.000mm. The size of the first distance and the second distance can be the same or different. The first spacing can be larger than the second spacing, or smaller than the second spacing. During the reflow soldering process, the object being soldered can enter the space between the upper and lower hot press assemblies from a larger spacing and exit from a smaller spacing. The height of the object being soldered before soldering is slightly higher than the height of the object being soldered after soldering.

[0056] like Figures 1 to 4 In the illustrated embodiment, the upper hot press body 141 is a flat plate, while the lower hot press body 151 is a flat plate. These flat plates evenly clamp the object being soldered and conduct heat evenly. This ensures that each solder joint on the object is heated stably and evenly, improving the soldering yield of fine-pitch LED chips.

[0057] like Figure 5 and Figure 6 In the embodiment of the hot pressing reflow soldering device for micro-pitch LED chip welding shown, the upper hot pressing body 141 includes an upper hot pressing plate 1411, an upper hot pressing roller group 1412, and an upper supporting bearing support 1413; the upper hot pressing roller group 1412 includes at least two or more upper hot pressing rollers 14121; the upper supporting bearing support 1413 is fixedly connected to the upper hot pressing plate 1411, and the bearing in the upper hot pressing roller 14121 is fixed at one end of the upper supporting bearing support 1413, and each upper hot pressing roller 14121 can rotate independently; each upper hot pressing roller 14121 in the upper hot pressing roller group 1412 is in contact with the upper surface of the upper flexible conveyor belt 12.

[0058] like Figure 5 and Figure 6In the embodiment of the hot pressing reflow soldering device for micro-pitch LED chip welding shown, the lower hot pressing body 151 includes a lower hot pressing plate 1511, a lower hot pressing roller group 1512, and a lower supporting bearing support 1513; the lower hot pressing roller group 1512 includes at least two or more lower hot pressing rollers 15121; the lower supporting bearing support 1513 is fixedly connected to the lower hot pressing plate 1511, and the bearing in the lower hot pressing roller 15121 is fixed at one end of the lower supporting bearing support 1513, and each lower hot pressing roller 15121 can rotate independently; each lower hot pressing roller 15121 in the lower hot pressing roller group 1512 is in contact with the lower surface of the lower flexible conveyor belt 13.

[0059] The upper hot pressing roller group 1412 can rotate and contact with the upper flexible conveyor belt 12, so that the heat of the upper hot pressing roller group 1412 can be transferred to the upper flexible conveyor belt more quickly and evenly, thereby ensuring the temperature stability of the upper flexible conveyor belt 12; similarly, the lower hot pressing roller group 1512 can rotate and contact with the lower flexible conveyor belt 13, so that the heat of the lower hot pressing roller group 1512 can be transferred to the lower flexible conveyor belt 13 more quickly and evenly, thereby ensuring the temperature stability of the lower flexible conveyor belt 13; the temperature stability of the upper flexible conveyor belt 12 and the lower flexible conveyor belt 13 ensures the contact temperature of the welded body during welding, and also helps to improve the uniformity and yield rate of welding.

[0060] like Figures 1 to 6 In the illustrated embodiment, the width of the upper and lower flexible conveyor belts is set between 50-1000 mm, and the thickness of the upper and lower flexible conveyor belts is set between 1-3 mm. This width is suitable for the size of fine-pitch LED chips, and the thickness of the upper and lower flexible conveyor belts provides them with a certain amount of heat storage capacity. This thickness also allows for rapid heat conduction, rapidly transferring heat from the upper and lower hot pressing bodies to the welded object via the upper and lower flexible conveyor belts.

[0061] like Figure 1 、 Figure 3 and Figure 5In the illustrated embodiment, the upper flexible conveyor belt control device includes an upper flexible conveyor belt drive device, an upper flexible conveyor belt drive roller 121, an upper flexible conveyor belt tensioning roller 125, and an upper flexible conveyor belt tensioning device. The ends of the upper flexible conveyor belt 12, which is closed into a loop, are respectively connected to the upper flexible conveyor belt drive roller 121 and the upper flexible conveyor belt tensioning roller 125. The upper flexible conveyor belt drive device drives the upper flexible conveyor belt drive roller 121 to rotate, and the rotation of the upper flexible conveyor belt drive roller 121 drives the upper flexible conveyor belt 12 to move. The upper flexible conveyor belt tensioning device controls the upper flexible conveyor belt tensioning roller 125, and the upper flexible conveyor belt tensioning device adjusts the tension of the upper flexible conveyor belt 12 through the upper flexible conveyor belt tensioning roller 125. The upper flexible conveyor belt drive device and the upper flexible conveyor belt tensioning device are not shown in the figure.

[0062] like Figure 1 、 Figure 3 and Figure 5 In the illustrated embodiment, the lower flexible conveyor belt control device includes a lower flexible conveyor belt drive device, a lower flexible conveyor belt drive roller 131, a lower flexible conveyor belt tensioning roller 135, and a lower flexible conveyor belt tensioning device. The ends of the lower flexible conveyor belt 13, which is closed into a loop, are respectively sleeved onto the lower flexible conveyor belt drive roller 131 and the lower flexible conveyor belt tensioning roller 135. The lower flexible conveyor belt drive device drives the lower flexible conveyor belt drive roller 131 to rotate, and the rotation of the lower flexible conveyor belt drive roller 131 drives the lower flexible conveyor belt 13. The lower flexible conveyor belt tensioning device controls the lower flexible conveyor belt tensioning roller 135, and adjusts the tension of the lower flexible conveyor belt 13 via the lower flexible conveyor belt tensioning roller 135. The lower flexible conveyor belt drive device and the lower flexible conveyor belt tensioning device are not shown in the figure.

[0063] The upper flexible conveyor belt tensioning device and the lower flexible conveyor belt tensioning device can respectively control the tensioning state of the upper flexible conveyor belt and the lower flexible conveyor belt, and conveniently adjust the distance between the upper flexible conveyor belt and the lower flexible conveyor belt; so that the distance can be adapted to the size of the welded body and the upper hot pressing body and

[0064] The spacing size between the lower hot pressing bodies.

[0065] The upper flexible conveyor belt driving device and the lower flexible conveyor belt driving device are two devices with the same structure, or they can be integrated into one device, which naturally synchronizes the rotation speed of the upper flexible conveyor belt and the lower flexible conveyor belt. Figure 2 、 Figure 4 and Figure 6In the illustrated embodiment, an embodiment of an upper flexible conveyor belt drive device and a lower flexible conveyor belt drive device is shown; in an embodiment of an upper flexible conveyor belt drive device, a drive motor 1211, a coupling 1212 and a drive shaft linkage gear 1213 are included; the upper flexible conveyor belt drive roller 121 is connected to the coupling 1212, the drive motor 1211 and the coupling 1212 are connected, and the flexible conveyor belt drive roller 121 is driven to rotate by the drive motor 1211.

[0066] The upper flexible conveyor belt tensioning device and the lower flexible conveyor belt tensioning device are devices with the same structure, or they can be integrated into one device, which naturally synchronizes the tensioning state of the upper flexible conveyor belt and the lower flexible conveyor belt; Figure 2 、 Figure 4 and Figure 6 In the illustrated embodiment, an upper flexible conveyor belt tensioning device 1251 and a lower flexible conveyor belt tensioning device 1351 are included.

[0067] like Figure 1 、 Figure 3 and Figure 5 In the illustrated embodiment, a first upper photoelectric sensor 1261, a second upper photoelectric sensor 1262, a first lower photoelectric sensor 1371 and a second lower photoelectric sensor 1372 are also included; the first upper photoelectric sensor 1261 and the second upper photoelectric sensor 1262 are respectively arranged at the two ends above the upper flexible conveyor belt 12, for detecting the temperature state of the upper flexible conveyor belt 12; the first lower photoelectric sensor 1371 and the second lower photoelectric sensor 1372 are respectively arranged at the two ends below the lower flexible conveyor belt 13, for detecting the temperature state of the lower flexible conveyor belt 13.

[0068] like Figure 3 The illustrated embodiment also includes a drive roller support frame 23. The drive roller support frame 23 is provided with a first drive bearing seat 2321 and a first drive bearing seat adjustment device 2322. The upper flexible conveyor belt drive roller bearing 23121 is connected to the first drive bearing seat 2321 for support. The first drive bearing seat adjustment device 2322 is used to adjust the position of the first drive bearing seat 2321 on the drive roller support frame 23, thereby adjusting the fixed position of the upper flexible conveyor belt drive roller 121 on the drive roller support frame 23. The drive roller support frame 23 is also provided with a second drive bearing seat 2324. The lower flexible conveyor belt drive roller bearing 23131 is connected to the second drive bearing seat 2324 for support. The position of the first drive bearing seat adjustment device 2322 on the drive roller support frame 23 can be adjusted using a first adjustment screw 23221.

[0069] like Figure 3The illustrated embodiment also includes a tensioning wheel support frame 27; a first tensioning bearing seat 2728 and a second tensioning bearing seat 2729 are mounted on the tensioning wheel support frame. The upper flexible conveyor belt tensioning roller bearing 27125 is connected to the first tensioning bearing seat 2728 for support, while the lower flexible conveyor belt tensioning roller bearing 27135 is connected to the second tensioning bearing seat 2729 for support. The position of the first tensioning bearing seat 2728 on the tensioning wheel support frame 27 can be adjusted using a tension adjustment screw 27281.

[0070] like Figure 3 The illustrated embodiment further includes a first main body bracket 25 and a second main body bracket 26; the first main body bracket 25 is provided with a first upper hot pressing assembly fixing portion 251 and a first lower hot pressing assembly fixing portion 252; the second main body bracket 26 is provided with a second upper hot pressing fixing portion 261 and a second lower hot pressing fixing portion 262; the upper hot pressing assembly 14 is horizontally fixedly connected to the first main body bracket 25 and the second main body bracket 26 via the first upper hot pressing assembly fixing portion 251 and the second upper hot pressing fixing portion 261, respectively; the lower hot pressing assembly 15 is horizontally fixedly connected to the first main body bracket 25 and the second main body bracket 26 via the first lower hot pressing assembly fixing portion 252 and the second lower hot pressing fixing portion 262, respectively. The first main body bracket 25 and the second main body bracket 26 can each be a gate-type bracket, or they can be combined to form a gate-type bracket.

[0071] In some embodiments not shown in the accompanying drawings, an upper flexible conveyor belt drive roller heating and temperature control device and an upper flexible conveyor belt tensioning roller heating and temperature control device are further provided; the upper flexible conveyor belt drive roller heating and temperature control device outputs heat energy to the upper flexible conveyor belt drive roller and controls the temperature of the upper flexible conveyor belt drive roller; the upper flexible conveyor belt tensioning roller heating and temperature control device outputs heat energy to the upper flexible conveyor belt tensioning roller and controls the temperature of the upper flexible conveyor belt tensioning roller; both ends of the upper flexible conveyor belt are respectively sleeved with the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller, and obtain heat energy from the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller;

[0072] In some embodiments not shown in the accompanying drawings, a lower flexible conveyor belt drive roller heating and temperature control device and a lower flexible conveyor belt tensioning roller heating and temperature control device are further provided; the lower flexible conveyor belt drive roller heating and temperature control device outputs heat energy to the lower flexible conveyor belt drive roller and controls the temperature of the lower flexible conveyor belt drive roller; the lower flexible conveyor belt tensioning roller heating and temperature control device outputs heat energy to the lower flexible conveyor belt tensioning roller and controls the temperature of the lower flexible conveyor belt tensioning roller; the two ends of the lower flexible conveyor belt are respectively connected to the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller, and obtain heat energy from the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller.

[0073] The upper flexible conveyor belt's drive roller heating and tension roller heating temperature control devices ensure continuous and stable energy input to the upper flexible conveyor belt during its circulation, maintaining its temperature stability. Similarly, the lower flexible conveyor belt's drive roller heating and tension roller heating temperature control devices ensure continuous and stable energy input to the lower flexible conveyor belt during its circulation, maintaining its temperature stability. The high temperature stability of the upper and lower flexible conveyor belts also ensures temperature stability for the welded components during welding, further facilitating the maintenance of welding temperature and ensuring uniformity and stability across each weld point.

[0074] The temperature of the upper flexible conveyor belt and the lower flexible conveyor belt can be set between 50-500℃ respectively. Such temperature setting can meet the requirements of most welding. The temperature setting of the upper flexible conveyor belt needs to be consistent with the temperature setting of the upper hot pressing assembly; the temperature setting of the lower flexible conveyor belt needs to be consistent with the temperature setting of the lower hot pressing assembly; the temperature setting of the upper flexible conveyor belt can be independent of the temperature setting of the lower flexible conveyor belt; that is, the temperature of the upper hot pressing assembly and the temperature of the lower hot pressing assembly can be set to different temperatures to adapt to the welding parts they are in contact with respectively; the temperature of the upper flexible conveyor belt and the temperature of the lower flexible conveyor belt can be set to different temperatures to adapt to the welding parts they are in contact with respectively.

[0075] An embodiment of a hot press reflow soldering method for soldering fine-pitch LED chips, not shown in some drawings, includes step A, step B, and step C.

[0076] In step A, an upper flexible conveyor belt and an upper flexible conveyor belt are arranged relative to each other and spaced apart, rotating continuously in the same direction. In step A, the width of the upper flexible conveyor belt and the lower flexible conveyor belt are set between 50 and 1000 mm; the thickness of the upper flexible conveyor belt and the lower flexible conveyor belt are set between 1 and 3 mm. Step A also includes heating the upper flexible conveyor belt using an upper flexible conveyor belt drive roller heating and temperature control device and an upper flexible conveyor belt tensioning roller heating and temperature control device; the upper flexible conveyor belt drive roller heating and temperature control device outputs heat energy to the upper flexible conveyor belt drive roller and controls the temperature of the upper flexible conveyor belt drive roller; the upper flexible conveyor belt tensioning roller heating and temperature control device outputs heat energy to the upper flexible conveyor belt tensioning roller and controls the temperature of the upper flexible conveyor belt tensioning roller; and the upper flexible conveyor belt is respectively connected to the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller at both ends, obtaining heat energy from the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller.

[0077] In step A, it also includes the step of heating the lower flexible conveyor belt by using the lower flexible conveyor belt drive roller heating and temperature control device and the lower flexible conveyor belt tensioning roller heating and temperature control device; the lower flexible conveyor belt drive roller heating and temperature control device outputs heat energy to the lower flexible conveyor belt drive roller and controls the temperature of the lower flexible conveyor belt drive roller; the lower flexible conveyor belt tensioning roller heating and temperature control device outputs heat energy to the lower flexible conveyor belt tensioning roller and controls the temperature of the lower flexible conveyor belt tensioning roller; the two ends of the lower flexible conveyor belt are respectively connected to the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller to obtain heat energy from the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller.

[0078] The upper flexible conveyor belt and the lower flexible conveyor belt are made of flexible heat-conducting materials such as metal and plastic.

[0079] In step B, an upper hot pressing assembly and a lower hot pressing assembly are arranged relative to each other and spaced apart; the upper hot pressing assembly is arranged above the upper flexible conveyor belt; and the lower hot pressing assembly is arranged below the lower flexible conveyor belt;

[0080] In step B, the temperatures of the upper and lower hot pressing assemblies can be set between 50-500° C. The distance between the upper and lower hot pressing assemblies can be adjusted; or the distance between the upper and lower hot pressing assemblies can be set to less than 10 mm.

[0081] In step B: the upper hot pressing assembly includes an upper hot pressing temperature control device and an upper hot pressing body; the upper hot pressing temperature control device is connected to the upper hot pressing body, and the upper hot pressing temperature control device outputs heat energy to the upper hot pressing body and controls the temperature of the upper hot pressing body; the lower hot pressing assembly includes a lower hot pressing temperature control device and a lower hot pressing body; the lower hot pressing temperature control device is connected to the lower hot pressing body, and the lower hot pressing temperature control device outputs heat energy to the lower hot pressing body and controls the temperature of the lower hot pressing body.

[0082] In step B: it also includes the step of adjusting the distance between the upper hot pressing assembly and the lower hot pressing assembly by using a first thickness gauge and a second thickness gauge; the two ends of the upper hot pressing assembly on the opposite side of the lower hot pressing assembly are respectively connected by a first thickness gauge; the vertical distance between one side of the upper hot pressing assembly and the corresponding side of the lower hot pressing assembly is called the first distance; the two first thickness gauges are used to adjust the size of the first distance and limit the thickness of the first distance; the two ends of the upper hot pressing assembly on the other side of the lower hot pressing assembly are respectively connected by a second thickness gauge; the vertical distance between the other side of the upper hot pressing assembly and the corresponding other side of the lower hot pressing assembly is called the second distance; the two second thickness gauges are used to adjust the size of the second distance and limit the thickness of the second distance; the adjustment range of the first distance and the second distance is 0.100-10.000mm.

[0083] In step C, the body to be welded is clamped between the upper flexible conveyor belt and the lower flexible conveyor belt during movement, and passes through the space between the upper hot pressing assembly and the lower hot pressing assembly to perform direct hot pressing and heat conduction reflow welding.

[0084] In a hot press reflow soldering device and method for soldering fine-pitch LED chips, an upper hot press assembly and a lower hot press assembly are arranged relative to each other and spaced apart. The upper hot press assembly is arranged above an upper flexible conveyor belt, while the lower hot press assembly is arranged below the lower flexible conveyor belt. An upper flexible conveyor belt control device is connected to the upper flexible conveyor belt to control the upper flexible conveyor belt's cyclic rotation. A lower flexible conveyor belt control device is connected to the lower flexible conveyor belt to control the lower flexible conveyor belt's cyclic rotation. The upper and lower flexible conveyor belts are arranged relative to each other and spaced apart. The upper and lower flexible conveyor belts jointly clamp the soldered object during movement, allowing the soldered object to pass through the space between the upper and lower hot press assemblies. This allows direct heat conduction between the upper and lower surfaces of the soldered object, thereby improving heat conduction efficiency during soldering, shortening the soldering heating time, and increasing the soldering yield rate.

[0085] In this application, the first and second in the names of each component are only for name distinction and do not represent a temporal and spatial sequence relationship.

[0086] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A hot press reflow soldering device for fine pitch LED chip soldering, characterized in that: It includes a reflow soldering device body, an upper flexible conveyor belt control device, an upper flexible conveyor belt, an upper hot pressing component, a lower flexible conveyor belt control device, a lower flexible conveyor belt, and a lower hot pressing component; The upper hot pressing assembly and the lower hot pressing assembly are respectively fixedly connected to the main body of the reflow soldering device; The upper hot pressing assembly and the lower hot pressing assembly are arranged opposite to each other and at a distance; The upper hot pressing assembly is arranged above the upper flexible conveyor belt; The lower hot pressing assembly is arranged below the lower flexible conveyor belt; The upper flexible conveyor belt control device is connected to the upper flexible conveyor belt to control the cyclic rotation of the upper flexible conveyor belt; The lower flexible conveyor belt control device is connected to the lower flexible conveyor belt to control the cyclic rotation of the lower flexible conveyor belt; The upper flexible conveyor belt and the lower flexible conveyor belt are arranged opposite to each other and spaced apart; the upper flexible conveyor belt and the lower flexible conveyor belt jointly clamp the welded body during movement, so that the welded body moves through the space between the upper hot pressing assembly and the lower hot pressing assembly; The spacing between the upper hot pressing assembly and the lower hot pressing assembly is adjustable; or the spacing between the upper hot pressing assembly and the lower hot pressing assembly is set to less than 10mm; The upper hot pressing assembly includes an upper hot pressing temperature control device and an upper hot pressing body; The upper hot pressing temperature control device is connected to the upper hot pressing body, and the upper hot pressing temperature control device outputs heat energy to the upper hot pressing body and controls the temperature of the upper hot pressing body; the temperature of the upper hot pressing assembly is set between 50-500 ℃; The lower hot pressing assembly includes a lower hot pressing temperature control device and a lower hot pressing body; the lower hot pressing temperature control device is connected to the lower hot pressing body, and the lower hot pressing temperature control device outputs heat energy to the lower hot pressing body and controls the temperature of the lower hot pressing body; the temperature of the lower hot pressing assembly is set between 50-500°C; The upper hot press assembly also includes an upper hot press pressure control device; the upper hot press pressure control device is connected to the upper hot press body, and the upper hot press pressure control device outputs a downward force on the upper hot press body, and the downward pressure generated by the force is in the range of 0.5-5MPa; the upper hot press pressure control device controls the distance between the upper hot press body and the lower hot press body; The lower hot press assembly also includes a lower hot press pressure control device; the lower hot press pressure control device is connected to the lower hot press body, and the lower hot press pressure control device outputs an upward force to the lower hot press body, and the pressure generated by the upward force is in the range of 0.5-5MPa; the lower hot press pressure control device controls the distance between the lower hot press body and the upper hot press body; or the lower hot press pressure control device and the upper hot press pressure control device jointly control the distance between the lower hot press body and the upper hot press body; The upper hot pressing body and / or the lower hot pressing body are flat hot pressing plates; The upper hot pressing pressure control device adjusts the distance between the upper hot pressing assembly and the lower hot pressing assembly, and presses the upper flexible conveyor belt downward so that when the upper flexible conveyor belt passes through the distance between the upper hot pressing assembly and the lower hot pressing assembly, the upper flexible conveyor belt has an angle of less than or equal to 5 degrees relative to the horizontal direction. o Angle.

2. The hot press reflow soldering device for fine pitch LED chip soldering according to claim 1, characterized in that: Also included are two first thickness gauges and two second thickness gauges; The two ends of the upper hot pressing assembly and the lower hot pressing assembly on opposite sides are respectively connected by a first thickness gauge; The vertical distance between one side of the upper hot pressing assembly and the corresponding side of the lower hot pressing assembly is called the first distance; the two first thickness gauges are used to adjust the size of the first distance and limit the thickness of the first distance; The two ends of the upper hot pressing assembly and the lower hot pressing assembly on the other side are respectively connected by a second thickness gauge; The vertical distance between the other side of the upper hot pressing assembly and the corresponding other side of the lower hot pressing assembly is called the second distance; the two second thickness gauges are used to adjust the size of the second distance and limit the thickness of the second distance; The adjustment range of the first spacing and the second spacing is 0.100-10.000 mm.

3. The hot press reflow soldering device for fine pitch LED chip soldering according to claim 1, characterized in that: The width of the upper flexible conveyor belt and the lower flexible conveyor belt is set between 50-1000mm; The thickness of the upper flexible conveyor belt and the lower flexible conveyor belt is set between 1-3 mm.

4. The hot press reflow soldering device for fine pitch LED chip soldering according to claim 1, characterized in that: The upper flexible conveyor belt control device includes an upper flexible conveyor belt drive roller, an upper flexible conveyor belt tensioning roller and an upper flexible conveyor belt tensioning device; the two ends of the upper flexible conveyor belt closed into a ring are respectively sleeved on the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller; when the upper flexible conveyor belt drive roller is driven to rotate, the upper flexible conveyor belt is driven to move; the upper flexible conveyor belt tensioning device controls the upper flexible conveyor belt tensioning roller, and the upper flexible conveyor belt tensioning roller adjusts the tension state of the upper flexible conveyor belt; The lower flexible conveyor belt control device includes a lower flexible conveyor belt driving roller, a lower flexible conveyor belt tensioning roller and a lower flexible conveyor belt tensioning device; the two ends of the lower flexible conveyor belt closed into a ring are respectively sleeved on the lower flexible conveyor belt driving roller and the lower flexible conveyor belt tensioning roller; when the lower flexible conveyor belt driving roller is driven to rotate, it drives the lower flexible conveyor belt to move; the lower flexible conveyor belt tensioning device controls the lower flexible conveyor belt tensioning roller, and the lower flexible conveyor belt tensioning roller adjusts the tensioning state of the lower flexible conveyor belt.

5. The hot press reflow soldering device for fine pitch LED chip soldering according to claim 4, characterized in that: It is also provided with an upper flexible conveyor belt drive roller heating and temperature control device, an upper flexible conveyor belt tensioning roller heating and temperature control device, a lower flexible conveyor belt drive roller heating and temperature control device, and a lower flexible conveyor belt tensioning roller heating and temperature control device; The upper flexible conveyor belt drive roller heating and temperature control device outputs heat energy to the upper flexible conveyor belt drive roller and controls the temperature of the upper flexible conveyor belt drive roller; the upper flexible conveyor belt tensioning roller heating and temperature control device outputs heat energy to the upper flexible conveyor belt tensioning roller and controls the temperature of the upper flexible conveyor belt tensioning roller; both ends of the upper flexible conveyor belt are respectively connected to the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller, and obtain heat energy from the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller; The lower flexible conveyor belt drive roller heating and temperature control device outputs heat energy to the lower flexible conveyor belt drive roller and controls the temperature of the lower flexible conveyor belt drive roller; the lower flexible conveyor belt tensioning roller heating and temperature control device outputs heat energy to the lower flexible conveyor belt tensioning roller and controls the temperature of the lower flexible conveyor belt tensioning roller; both ends of the lower flexible conveyor belt are respectively sleeved with the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller, and obtain heat energy from the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller; The temperatures of the upper flexible conveyor belt and the lower flexible conveyor belt are respectively set between 50-500°C.

6. A hot press reflow soldering method for fine pitch LED chip soldering, characterized in that: include, Step A: Arranging an upper flexible conveyor belt and a lower flexible conveyor belt that rotate continuously in the same direction relative to each other and at a distance; Step B: Arranging an upper hot pressing assembly and a lower hot pressing assembly relative to each other and with a distance therebetween; the upper hot pressing assembly is arranged above the upper flexible conveyor belt; and the lower hot pressing assembly is arranged below the lower flexible conveyor belt; Step C: The body to be welded is clamped between the upper and lower flexible conveyor belts during movement, and passes through the space between the upper and lower hot pressing assemblies to perform double-sided direct hot pressing and heat conduction reflow welding; Step B: the spacing between the upper hot pressing assembly and the lower hot pressing assembly is adjustable; or the spacing between the upper hot pressing assembly and the lower hot pressing assembly is set at less than 10mm; In step B: the upper hot pressing assembly includes an upper hot pressing temperature control device and an upper hot pressing body; the upper hot pressing temperature control device is connected to the upper hot pressing body, the upper hot pressing temperature control device outputs heat energy to the upper hot pressing body and controls the temperature of the upper hot pressing body; the temperature of the upper hot pressing assembly is set between 50-500°C; The lower hot pressing assembly includes a lower hot pressing temperature control device and a lower hot pressing body; the lower hot pressing temperature control device is connected to the lower hot pressing body, and the lower hot pressing temperature control device outputs heat energy to the lower hot pressing body and controls the temperature of the lower hot pressing body; the temperature of the lower hot pressing assembly is set between 50-500°C; The upper hot press assembly also includes an upper hot press pressure control device; the upper hot press pressure control device is connected to the upper hot press body, and the upper hot press pressure control device outputs a downward force on the upper hot press body, and the downward pressure generated by the force is in the range of 0.5-5MPa; the upper hot press pressure control device controls the distance between the upper hot press body and the lower hot press body; The lower hot pressing assembly also includes a lower hot pressing pressure control device; the lower hot pressing pressure control device is connected to the lower hot pressing body, and the lower hot pressing pressure control device outputs an upward force to the lower hot pressing body, and the upward pressure generated by the force is in the range of 0.5-5MPa; the lower hot pressing pressure control device controls the distance between the lower hot pressing body and the upper hot pressing body; or the lower hot pressing pressure control device and the upper hot pressing pressure control device jointly control the distance between the lower hot pressing body and the upper hot pressing body.

7. The hot press reflow soldering method for fine pitch LED chip soldering according to claim 6, characterized in that: In step B: the step of adjusting the distance between the upper hot pressing assembly and the lower hot pressing assembly by using the first thickness gauge and the second thickness gauge is also included; The two ends of the upper hot pressing assembly and the lower hot pressing assembly on opposite sides are respectively connected by a first thickness gauge; the vertical distance between one side of the upper hot pressing assembly and the corresponding side of the lower hot pressing assembly is called the first distance; the two first thickness gauges are used to adjust the size of the first distance and limit the thickness of the first distance; The two ends of the upper hot pressing assembly and the lower hot pressing assembly on the other side are respectively connected by a second thickness gauge; The vertical distance between the other side of the upper hot pressing assembly and the corresponding other side of the lower hot pressing assembly is called the second distance; the two second thickness gauges are used to adjust the size of the second distance and limit the thickness of the second distance; The adjustment range of the first spacing and the second spacing is 0.100-10.000 mm.

8. The hot press reflow soldering method for fine pitch LED chip soldering according to claim 6, characterized in that: In step A, the width of the upper flexible conveyor belt and the lower flexible conveyor belt is set between 50-1000 mm; the thickness of the upper flexible conveyor belt and the lower flexible conveyor belt is set between 1-3 mm; In step A, the step of heating the upper flexible conveyor belt by using the upper flexible conveyor belt driving roller heating temperature control device and the upper flexible conveyor belt tensioning roller heating temperature control device is also included; The upper flexible conveyor belt drive roller heating and temperature control device outputs heat energy to the upper flexible conveyor belt drive roller and controls the temperature of the upper flexible conveyor belt drive roller; the upper flexible conveyor belt tensioning roller heating and temperature control device outputs heat energy to the upper flexible conveyor belt tensioning roller and controls the temperature of the upper flexible conveyor belt tensioning roller; the two ends of the upper flexible conveyor belt closed into a ring are respectively connected to the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller, and obtain heat energy from the upper flexible conveyor belt drive roller and the upper flexible conveyor belt tensioning roller; The temperature of the upper flexible conveyor belt is set between 50-500℃; In step A, the step of heating the lower flexible conveyor belt by using the lower flexible conveyor belt driving roller heating temperature control device and the lower flexible conveyor belt tensioning roller heating temperature control device is also included; The lower flexible conveyor belt drive roller heating and temperature control device outputs heat energy to the lower flexible conveyor belt drive roller and controls the temperature of the lower flexible conveyor belt drive roller; the lower flexible conveyor belt tensioning roller heating and temperature control device outputs heat energy to the lower flexible conveyor belt tensioning roller and controls the temperature of the lower flexible conveyor belt tensioning roller; the two ends of the lower flexible conveyor belt closed into a ring are respectively connected to the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller, and obtain heat energy from the lower flexible conveyor belt drive roller and the lower flexible conveyor belt tensioning roller; The temperature of the lower flexible conveyor belt is set between 50-500°C.

Images