Flip chip packaging process

Abstract

The invention discloses a flip chip packaging process, which comprises the following steps of: preparing a chip which is provided with a plurality of conductive bumps; preparing a circuit substrate, wherein the circuit substrate is respectively provided with a welding pad corresponding to each conductive bump; a 3D array nozzle printing device is used for spraying the scaling powder on the surfaces of the welding pads; overturning and aligning the chip, and carrying out metal welding operation to prepare a flip chip packaging structure; filling a liquid material to cover the substance to be cleaned on the circuit substrate; placing the flip chip packaging structure in a closed processing chamber, and heating the flip chip packaging structure to a preset temperature; a pressure increasing and reducing device and / or a vacuum generator are / is used for generating intermittent pressure increasing and reducing and / or intermittent vacuumizing on the gas in the processing chamber, and the liquid material is rubbed and scrubbed back and forth by utilizing the fluctuation change of the gas, so that the substance to be cleaned is taken away from the circuit substrate.

Description

Technical Field

[0001] The present invention relates to the technical field of flip chip packaging, and more particularly to a flip chip packaging process provided by the technology, wherein a 3D array nozzle printing device is used to accurately control the spraying range and spraying dosage of the solder flux, so as to minimize the amount of residual solder flux after metal welding, and liquid materials are combined with intermittent air flow fluctuations of increasing and decreasing pressure to drive the liquid materials to create a rubbing or stirring effect, thereby improving the cleaning efficiency of the residues, effectively simplifying the flip chip packaging process, and greatly improving the production efficiency. Background Art

[0002] In an era of rapid technological advancement, high-tech electronic technologies have emerged one after another, allowing more user-friendly and better-functioning electronic products to be continuously innovated and designed in a trend of being light, thin, short and small. In order to achieve the above requirements, it is necessary to meet the requirements of high-speed processing, multi-function, integration, small size, light weight and low price of electronic components. For this reason, integrated circuit packaging technology has also developed towards miniaturization and high density. Among various packaging technologies, flip chip package (F / C package) and other high-density integrated circuit packaging technologies that use bumps or solder balls for electrical connection have gradually become the mainstream of high-density packaging because they can shorten the wiring length and thus increase the signal transmission speed.

[0003] In the existing flip chip packaging process, adhesive is often used for bonding between materials. Especially when bonding metals, some adhesives usually have high acid content and are corrosive to remove the tight oxide layer formed on the bonding surface. However, the corrosive nature of this adhesive seriously affects the performance of microelectronic components. Therefore, a cleaning step must be performed to remove the adhesive remaining on the bonding surface or the reaction residue between the adhesive and the metal oxide. Some adhesives will also leave some organic matter and leave a layer of grease film on the bonding surface after use. Such grease must also be cleaned again to avoid subsequent reliability problems for semiconductor components. However, when the circuits on the circuit substrate become denser or the protrusions on the circuit substrate for bonding become smaller or the gap between the circuit substrate and the pad bonding becomes narrower, the above-mentioned residues become more and more difficult to clean. If the corrosive adhesive remaining on the circuit substrate or the joint is not completely removed, the reliability of the component will be greatly reduced. In addition, the current common method of using cleaning solvents to clean the above-mentioned residues will cause impact on the environment if improperly handled, and it is necessary to improve it.

[0004] Therefore, in view of the problems existing in the above-mentioned existing flip chip packaging process, how to develop a packaging process that is more ideal, practical and economical has become the goal and direction for the relevant industry to actively develop breakthroughs.

[0005] In view of this, the inventor, based on his many years of experience in manufacturing, developing and designing related products, has designed and carefully evaluated the above-mentioned goals and finally obtained a practical invention. Summary of the invention

[0006] The technical problem to be solved by the present invention is that the existing flip chip packaging process often requires the use of adhesives for inter-material bonding, especially when bonding metals. Some adhesives usually have a high acid content and are corrosive to remove the tight oxide layer formed on the bonding surface. However, the corrosive nature of this adhesive seriously affects the performance of microelectronic components. Therefore, a cleaning step must be performed to remove the adhesive remaining on the bonding surface or the reaction residues of the adhesive and the metal oxide. However, when the circuits on the circuit substrate become denser or the protrusions on the circuit substrate for bonding become smaller or the gap between the circuit substrate and the pad becomes narrower, the above-mentioned residues become more and more difficult to clean, and there is a need for improvement.

[0007] The object of the present invention is to provide a flip chip packaging process to improve the above-mentioned problem.

[0008] To achieve the above object, the present invention provides a flip chip packaging process, the steps of which include:

[0009] a. Prepare a chip, wherein the chip has an active surface, and a plurality of conductive bumps are arranged on the active surface, and the conductive bumps are composed of at least one of tin, silver, copper, gold, indium, lead, bismuth, zinc, nickel, or other materials that are conducive to welding.

[0010] b. Prepare a circuit substrate, wherein the circuit substrate is provided with a carrying surface, and a soldering pad is respectively arranged on the carrying surface corresponding to each of the conductive bumps.

[0011] c. Use a 3D array nozzle printing device to spray flux onto the surface of each solder pad. Through the program setting of the 3D array nozzle printing device, the spraying range and spraying dosage of the flux can be accurately controlled, which can effectively avoid spraying outside each solder pad area.

[0012] d. Turn the chip over and align it so that the active surface of the chip faces the supporting surface of the circuit substrate, and each of the conductive bumps is respectively connected to each of the pads via flux, followed by a metal welding operation, so that the chip is electrically and structurally connected to each of the pads on the circuit substrate via each of the conductive bumps, to form a flip-chip package structure, so that signals can be transmitted between the circuit substrate and the chip.

[0013] e. Filling a liquid material between the circuit substrate and the chip to cover a substance to be cleaned on the circuit substrate.

[0014] f. placing the flip chip package structure containing the liquid material in a closed processing chamber, heating the processing chamber to a predetermined temperature, the predetermined temperature must be matched with the viscosity of the liquid material, between 25 and 200° C., to increase the fluidity of the liquid material.

[0015] g. Using a vacuum generator to intermittently evacuate the gas in the processing chamber to produce a wave-like gas flow, which is a fluctuation under vacuum, ranging from a maximum value of no more than 1 atmosphere to a minimum value of 10 -5 The atmospheric pressure fluctuates intermittently, and the fluctuation of the gas vacuum suction is used to cause the fluctuation of the liquid material, so that the liquid material in contact with the material to be cleaned is rubbed back and forth with a larger amplitude, and the material to be cleaned attached to the circuit substrate is more effectively removed from the circuit substrate, achieving an effect that traditional solution cleaning cannot achieve.

[0016] The present invention also provides another flip chip packaging process, the steps of which include:

[0017] a. Prepare a chip, wherein the chip has an active surface, and a plurality of conductive bumps are arranged on the active surface, and the conductive bumps are composed of at least one of tin, silver, copper, gold, indium, lead, bismuth, zinc, nickel, or other materials that are conducive to welding.

[0018] b. Prepare a circuit substrate, wherein the circuit substrate is provided with a carrying surface, and a soldering pad is respectively arranged on the carrying surface corresponding to each of the conductive bumps.

[0019] c. Use a 3D array nozzle printing device to spray flux onto the surface of each solder pad. Through the program setting of the 3D array nozzle printing device, the spraying range and spraying dosage of the flux can be accurately controlled, which can effectively avoid spraying outside each solder pad area.

[0020] d. Turn the chip over and align it so that the active surface of the chip faces the supporting surface of the circuit substrate, and each of the conductive bumps is respectively connected to each of the pads via flux, followed by a metal welding operation, so that the chip is electrically and structurally connected to each of the pads on the circuit substrate via each of the conductive bumps, to form a flip-chip package structure, so that signals can be transmitted between the circuit substrate and the chip.

[0021] e. Filling a liquid material between the circuit substrate and the chip to cover a substance to be cleaned on the circuit substrate.

[0022] f. placing the flip chip package structure containing the liquid material in a closed processing chamber, heating the processing chamber to a predetermined temperature, the predetermined temperature must be matched with the viscosity of the liquid material, between 25 and 200° C., to increase the fluidity of the liquid material.

[0023] g. Use a pressure increasing and reducing device and a vacuum generator to intermittently increase and decrease the pressure and intermittently evacuate the gas in the chamber to produce a wave-like airflow, which is a fluctuation from high pressure to vacuum, ranging from a maximum of 50 atmospheres to a minimum of 10 -5 The atmospheric pressure fluctuates intermittently, and the fluctuation of the gas is used to cause the fluctuation of the liquid material. The liquid material in contact with the material to be cleaned is rubbed back and forth, and the material to be cleaned attached to the circuit substrate is more effectively removed from the circuit substrate, achieving an effect that traditional solution cleaning cannot achieve.

[0024] The present invention provides another flip chip packaging process, the steps of which include:

[0025] a. Prepare a chip, wherein the chip has an active surface, and a plurality of conductive bumps are arranged on the active surface, and the conductive bumps are composed of at least one of tin, silver, copper, gold, indium, lead, bismuth, zinc, nickel, or other materials that are conducive to welding.

[0026] b. Prepare a circuit substrate, wherein the circuit substrate is provided with a carrying surface, and a soldering pad is respectively arranged on the carrying surface corresponding to each of the conductive bumps.

[0027] c. Use a 3D array nozzle printing device to spray flux onto the surface of each solder pad. Through the program setting of the 3D array nozzle printing device, the spraying range and spraying dosage of the flux can be accurately controlled, which can effectively avoid spraying outside each solder pad area.

[0028] d. Turn the chip over and align it so that the active surface of the chip faces the supporting surface of the circuit substrate, and each of the conductive bumps is respectively connected to each of the pads via flux, followed by a metal welding operation, so that the chip is electrically and structurally connected to each of the pads on the circuit substrate via each of the conductive bumps, to form a flip-chip package structure, so that signals can be transmitted between the circuit substrate and the chip.

[0029] e. Filling a liquid material between the circuit substrate and the chip to cover a substance to be cleaned on the circuit substrate.

[0030] f. placing the flip chip package structure containing the liquid material in a closed processing chamber, heating the processing chamber to a predetermined temperature, the predetermined temperature must be matched with the viscosity of the liquid material, between 25 and 200° C., to increase the fluidity of the liquid material.

[0031] g. Use an increasing / decreasing pressure device to intermittently increase / decrease the pressure of the gas in the processing chamber to produce a wavy airflow, which fluctuates from high pressure to 1 atmosphere, and fluctuates intermittently between a maximum value of 50 atmospheres and a minimum value of 1 atmosphere. The fluctuating changes of the gas are used to cause the fluctuating changes of the liquid material, so that the liquid material in contact with the material to be cleaned is rubbed back and forth, and the material to be cleaned attached to the circuit substrate is more effectively removed from the circuit substrate, achieving an effect that traditional solution cleaning cannot achieve.

[0032] As mentioned above, the soldering flux is a liquid soldering flux, and the viscosity of the liquid soldering flux is in the range of 1 centipoise (cps) to 100 centipoises.

[0033] As mentioned above, the substance to be cleaned is soldering flux, soldering flux residue, oil, photoresist or products generated during the manufacturing process.

[0034] As mentioned above, the liquid material is a base glue, which may contain hard particles. The hard particles roll back and forth with the fluctuation of the base glue, and the friction and scrubbing effect is increased by the hard particles, which helps to clean the substances to be removed.

[0035] As mentioned above, the primer component is epoxy resin doped with fillers such as silicon dioxide (SiO2) powder.

[0036] Compared with the efficacy of the prior art: the flip chip packaging process of the present invention uses a 3D array nozzle printing device to accurately control the spraying range and spraying dosage of the solder flux, so that the residual solder flux residue after the metal welding operation is extremely small, and the fluctuation of the gas in the processing chamber is controlled to cause the fluctuation of the liquid material, so that it produces a back-and-forth friction and rubbing cleaning effect like washing clothes, or accelerates the dissolution of the substance to be cleaned in the liquid material, such as adding sugar to water and applying stirring to accelerate the dissolution of sugar, so that the liquid material in contact with the substance to be cleaned is washed by back-and-forth friction and rubbing. The substances to be cleaned attached to the circuit substrate are taken away from the circuit substrate, so that the cleaning efficiency of the residues is improved, the flip chip packaging process is effectively simplified, and the production efficiency is greatly improved; in addition, heating the processing chamber temperature to between 25 and 200°C in the processing chamber will also cause the grease film, part of the substances to be cleaned or the water vapor adsorbed inside the circuit substrate to volatilize and generate gas due to the heat. Through the fluctuation under vacuum, the fluctuation from high pressure to 1 atmosphere or the fluctuation from high pressure to vacuum, the fluctuation of the gas causes the fluctuation of the liquid material, and the gas can also be discharged from the liquid material.

[0037] With regard to the technology, means and effects adopted by the present invention, several preferred embodiments are given below with detailed descriptions with reference to the drawings. It is believed that the above-mentioned purpose, structure and features of the present invention can be deeply and specifically understood thereby. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 FIG. 1 is a flowchart of a flip chip packaging process according to an embodiment of the present invention.

[0039] Figure 2 FIG. 4 is a flowchart of a flip chip packaging process according to another embodiment of the present invention.

[0040] Figure 3 FIG. 4 is a flowchart of a flip chip packaging process according to another embodiment of the present invention.

[0041] 4A to 4F for Figure 1-Figure 3 A cross-sectional diagram of the flip chip packaging process.

[0042] Explanation of the reference numerals: 21a-27a~step; 21b-27b~step; 21c-27c~step; 300~flip chip packaging structure; 310~chip; 311~active surface; 320~conductive bump; 330~circuit substrate; 331~bearing surface; 332~soldering pad; 340~3D array nozzle printing device; 341~flux spraying layer; 350~nozzle; 410~liquid material; 510~processing chamber. DETAILED DESCRIPTION

[0043] See also Figure 1 and 4A to 4F As shown, Figure 1 FIG. 1 is a flow chart of a flip chip packaging process according to an embodiment of the present invention. 4A to 4F The present invention provides a cross-sectional schematic diagram of a flip chip packaging process, and the steps of the flip chip packaging process include:

[0044] a. (Step 21a) preparing a chip 310, wherein the chip 310 has an active surface 311, and a plurality of conductive bumps 320 (such as Figure 4A As shown in FIG. 1 , the conductive bump 320 is a solder bump made by a general bumping process, and its composition is at least one of tin, silver, copper, gold, indium, lead, bismuth, zinc, nickel, or other materials that are conducive to welding.

[0045] b. (Step 22a) preparing a circuit substrate 330, wherein the circuit substrate 330 has a carrying surface 331, and a pad 332 (such as Figure 4B shown).

[0046] c. (Step 23a) A 3D array nozzle printing device 340 is used to spray flux onto the surface of each pad 332. The spraying range and spraying dosage of the flux can be accurately controlled through the program setting of the 3D array nozzle printing device 340, and the flux sprayed onto the surface of each pad 332 can be effectively prevented from overflowing. The flux spraying is to use the 3D array nozzle printing device 340 to pre-define the coordinates of a plurality of nozzles 350 and accurately locate the position of each pad 332 on the circuit substrate 330 and the range to be sprayed, and the 3D array nozzle printing device 340 stacks a plurality of flux spray layers 341 (such as Figure 4C As shown), the flux adopts liquid flux, and its main function is to remove the oxides on the surface of the solder and the base material to be welded, so that the welding surface reaches the necessary cleanliness, prevents the surface from being oxidized again during welding, reduces the surface tension of the liquid solder, and significantly improves the wetting performance.

[0047] d. (Step 24a) Turn the chip 310 over and align it so that the active surface 311 of the chip 310 faces the supporting surface 331 of the circuit substrate 330, and each conductive bump 320 is respectively connected to each pad 332 via a soldering flux (such as Figure 4D As shown in the figure, a metal welding operation is subsequently performed so that the chip 310 is electrically and structurally connected to the pads 332 on the circuit substrate 330 through the conductive bumps 320 to form a flip-chip package structure 300, so that signals can be transmitted between the circuit substrate 330 and the chip 310. The metal welding (such as reflow) performed here is to perform metal welding on the aligned chip 310 and the circuit substrate 330 and the conductive bumps 320 and the pads 332, so that the conductive bumps 320 in a molten or semi-molten state are combined with the pads 332 on the supporting surface 331 of the circuit substrate 330.

[0048] e. (Step 25a) Fill a liquid material 410 between the circuit substrate 330 and the chip 310 to cover a substance to be cleaned on the circuit substrate (such as Figure 4E shown).

[0049] f. (Step 26a) placing the flip chip package structure 300 containing the liquid material 410 in a closed processing chamber 510 (eg Figure 4F As shown), the processing chamber 510 is heated to a predetermined temperature, which is matched with the viscosity of the liquid material and is between 25 and 200° C., so as to increase the fluidity of the liquid material.

[0050] g. (Step 27a) intermittently evacuate the gas in the processing chamber 510 with a vacuum generator (not shown) to generate a wave-like gas flow, which is a fluctuation under vacuum, ranging from a maximum value of no more than 1 atmosphere to a minimum value of 10 -5 The atmospheric pressure fluctuates intermittently, and the fluctuation of the gas vacuum suction force is used to cause the fluctuation of the liquid material 410. The liquid material 410 existing in the chip 310 and the circuit substrate 330 can be pulled by the capillary force between each other and the surface tension of the liquid material 410, and there will be no overflow problem under larger fluctuations. The liquid material 410 in contact with the material to be cleaned is rubbed back and forth with a larger amplitude, and the material to be cleaned attached to the circuit substrate 330 is more effectively removed from the circuit substrate 330, achieving an effect that traditional solution cleaning cannot achieve. The liquid material 410 is pulled by the fluctuation of the gas to cause liquid fluctuations, which can reduce the direct energy transfer and reduce the damage to objects or splashing of the liquid material 410 caused by excessive fluctuations.

[0051] As mentioned above, the viscosity of the liquid soldering flux is in the range of 1 centipoise (cps) to 100 centipoises.

[0052] As mentioned above, the substance to be cleaned is soldering flux, soldering flux residue, oil, photoresist or products generated during the manufacturing process.

[0053] As mentioned above, the liquid material 410 is a base glue, which may contain hard particles. The hard particles roll back and forth with the fluctuation of the base glue, and the friction and scrubbing effect is increased by the hard particles, which helps to clean the substances to be removed.

[0054] As mentioned above, the primer component is epoxy resin doped with fillers such as silicon dioxide (SiO2) powder.

[0055] See also Figure 2 and 4A to 4F As shown, Figure 2 is a flow chart of a flip chip packaging process according to another embodiment of the present invention, and 4A to 4F The present invention provides a cross-sectional schematic diagram of a flip chip packaging process, and the steps of the flip chip packaging process include:

[0056] a. (Step 21b) preparing a chip 310, wherein the chip 310 has an active surface 311, and a plurality of conductive bumps 320 (such as Figure 4A As shown in FIG. 1 , the conductive bump 320 is a solder bump made by a general bumping process, and its composition is at least one of tin, silver, copper, gold, indium, lead, bismuth, zinc, nickel, or other materials that are conducive to welding.

[0057] b. (Step 22b) preparing a circuit substrate 330, wherein the circuit substrate 330 has a carrying surface 331, and a pad 332 (such as Figure 4B shown).

[0058] c. (Step 23b) A 3D array nozzle printing device 340 is used to spray flux onto the surface of each pad 332. The spraying range and spraying dosage of the flux can be precisely controlled by the program setting of the 3D array nozzle printing device 340, and the flux sprayed onto the surface of each pad 332 can be effectively prevented from overflowing. The flux spraying is performed by using the 3D array nozzle printing device 340 to pre-define the coordinates of a plurality of nozzles 350 and precisely locate the positions of each pad 332 on the circuit substrate 330 and the range to be sprayed. The 3D array nozzle printing device 340 stacks a plurality of flux spraying layers 341 (such as Figure 4C As shown), the flux adopts liquid flux, and its main function is to remove the oxides on the surface of the solder and the base material to be welded, so that the welding surface reaches the necessary cleanliness, prevents the surface from being oxidized again during welding, reduces the surface tension of the liquid solder, and significantly improves the wetting performance.

[0059] d. (Step 24b) Turn the chip 310 over and align it so that the active surface 311 of the chip 310 faces the supporting surface 331 of the circuit substrate 330, and each conductive bump 320 is respectively connected to each pad 332 via a soldering flux (such as Figure 4D As shown in the figure, a metal welding operation is subsequently performed so that the chip 310 is electrically and structurally connected to the pads 332 on the circuit substrate 330 through the conductive bumps 320 to form a flip-chip package structure 300, so that signals can be transmitted between the circuit substrate 330 and the chip 310. The metal welding (such as reflow) performed here is to perform metal welding on the aligned chip 310 and the circuit substrate 330 and the conductive bumps 320 and the pads 332, so that the conductive bumps 320 in a molten or semi-molten state are combined with the pads 332 on the supporting surface 331 of the circuit substrate 330.

[0060] e. (Step 25b) Fill a liquid material 410 between the circuit substrate 330 and the chip 310 to cover a substance to be cleaned on the circuit substrate (such as Figure 4E shown).

[0061] f. (Step 26b) placing the flip chip package structure 300 containing the liquid material 410 in a closed processing chamber 510 (eg Figure 4FAs shown), the processing chamber 510 is heated to a predetermined temperature, which is matched with the viscosity of the liquid material and is between 25 and 200° C., so as to increase the fluidity of the liquid material.

[0062] g. (Step 27b) Using a pressure increasing and decreasing device (not shown) and a vacuum generator (not shown) to intermittently increase and decrease the pressure and intermittently evacuate the gas in the processing chamber 510 to generate a wave-like gas flow, which is a fluctuation from high pressure to vacuum, ranging from a maximum of 50 atmospheres to a minimum of 10 -5 The atmospheric pressure fluctuates intermittently, and the fluctuation of the gas is used to cause the fluctuation of the liquid material 410. The liquid material 410 existing in the chip 310 and the circuit substrate 330 can be pulled by the capillary force between each other and the surface tension of the liquid material 410, and there will be no overflow problem even under larger fluctuations. The liquid material 410 in contact with the material to be cleaned can be rubbed back and forth, and the material to be cleaned attached to the circuit substrate 330 can be more effectively removed from the circuit substrate 330, achieving an effect that traditional solution cleaning cannot achieve. The liquid material 410 is pulled by the fluctuation of the gas to cause liquid fluctuations, which can reduce the direct energy transfer and reduce the damage to objects or splashing of the liquid material 410 caused by excessive fluctuations.

[0063] As mentioned above, the viscosity of the liquid soldering flux is in the range of 1 centipoise (cps) to 100 centipoises.

[0064] As mentioned above, the substance to be cleaned is soldering flux, soldering flux residue, oil, photoresist or products generated during the manufacturing process.

[0065] As mentioned above, the liquid material 410 is a base glue, which may contain hard particles. The hard particles roll back and forth with the fluctuation of the base glue, and the friction and scrubbing effect is increased by the hard particles, which helps to clean the substances to be removed.

[0066] As mentioned above, the primer component is epoxy resin doped with fillers such as silicon dioxide (SiO2) powder.

[0067] See also Figure 3 and 4A to 4F As shown, Figure 3 is a flowchart of a flip chip packaging process according to another embodiment of the present invention, and 4A to 4F The present invention provides a cross-sectional schematic diagram of a flip chip packaging process, and the steps of the flip chip packaging process include:

[0068] a. (Step 21c) preparing a chip 310, wherein the chip 310 has an active surface 311, and a plurality of conductive bumps 320 (such as Figure 4A As shown in FIG. 1 , the conductive bump 320 is a solder bump made by a general bumping process, and its composition is at least one of tin, silver, copper, gold, indium, lead, bismuth, zinc, nickel, or other materials that are conducive to welding.

[0069] b. (Step 22c) preparing a circuit substrate 330, wherein the circuit substrate 330 has a carrying surface 331, and a pad 332 (such as Figure 4B shown).

[0070] c. (Step 23c) A 3D array nozzle printing device 340 is used to spray flux onto the surface of each pad 332. The spraying range and spraying dosage of the flux can be accurately controlled through the program setting of the 3D array nozzle printing device 340, and the flux sprayed onto the surface of each pad 332 can be effectively prevented from overflowing. The flux spraying is to use the 3D array nozzle printing device 340 to pre-define the coordinates of a plurality of nozzles 350 and accurately locate the position of each pad 332 on the circuit substrate 330 and the range to be sprayed, and the 3D array nozzle printing device 340 stacks a plurality of flux spraying layers 341 (such as Figure 4C As shown), the flux adopts liquid flux, and its main function is to remove the oxides on the surface of the solder and the base material to be welded, so that the welding surface reaches the necessary cleanliness, prevents the surface from being oxidized again during welding, reduces the surface tension of the liquid solder, and significantly improves the wetting performance.

[0071] d. (Step 24c) Turn the chip 310 over and align it so that the active surface 311 of the chip 310 faces the supporting surface 331 of the circuit substrate 330, and each conductive bump 320 is respectively connected to each pad 332 via a soldering flux (such as Figure 4D As shown in the figure, a metal welding operation is subsequently performed so that the chip 310 is electrically and structurally connected to the pads 332 on the circuit substrate 330 through the conductive bumps 320 to form a flip-chip package structure 300, so that signals can be transmitted between the circuit substrate 330 and the chip 310. The metal welding (such as reflow) performed here is to perform metal welding on the aligned chip 310 and the circuit substrate 330 and the conductive bumps 320 and the pads 332, so that the conductive bumps 320 in a molten or semi-molten state are combined with the pads 332 on the supporting surface 331 of the circuit substrate 330.

[0072] e. (Step 25c) Fill a liquid material 410 between the circuit substrate 330 and the chip 310 to cover a substance to be cleaned on the circuit substrate (such as Figure 4Eshown).

[0073] f. (Step 26c) placing the flip chip package structure 300 containing the liquid material 410 in a closed processing chamber 510 (eg Figure 4F As shown), the processing chamber 510 is heated to a predetermined temperature, which is matched with the viscosity of the liquid material and is between 25 and 200° C., so as to increase the fluidity of the liquid material.

[0074] g. (Step 27c) An increasing / decreasing pressure device (not shown) is used to intermittently increase / decrease the pressure of the gas in the processing chamber 510 to generate a wavy airflow, which fluctuates from high pressure to 1 atmosphere, and fluctuates intermittently between a maximum value of 50 atmospheres and a minimum value of 1 atmosphere. The fluctuation of the gas is used to cause the fluctuation of the liquid material 410. The liquid material 410 existing in the chip 310 and the circuit substrate 330 can be pulled by the capillary force between them and the surface tension of the liquid material 410 so that the liquid material 410 will not overflow even when a larger fluctuation is generated. The liquid material 410 in contact with the material to be cleaned can be rubbed back and forth to more effectively remove the material to be cleaned attached to the circuit substrate 330 from the circuit substrate 330, achieving an effect that cannot be achieved by traditional solution cleaning. The fluctuation of the gas can pull the liquid material to fluctuate, which can reduce the direct energy transfer and reduce the damage to the object or the splashing of the liquid material 410 caused by excessive fluctuation.

[0075] As mentioned above, the viscosity of the liquid soldering flux is in the range of 1 centipoise (cps) to 100 centipoises.

[0076] As mentioned above, the material to be cleaned is soldering flux, soldering flux residue, oil, photoresist or products generated during the manufacturing process.

[0077] As mentioned above, the liquid material 410 is a base glue, which may contain hard particles. The hard particles roll back and forth with the fluctuation of the base glue, and the friction and scrubbing effect is increased by the hard particles, which helps to clean the substances to be removed.

[0078] As mentioned above, the primer component is epoxy resin doped with fillers such as silicon dioxide (SiO2) powder.

[0079] The foregoing text specifically describes the technical features of the present invention with respect to the preferred embodiments of the present invention; however, persons familiar with the technology may make changes and modifications to the present invention without departing from the spirit and principles of the present invention, and such changes and modifications should all be included in the scope defined by the claims of the present invention.

Claims

1. A flip chip packaging process, characterized in that: The steps include: (a) preparing a chip, wherein the chip has an active surface, and a plurality of conductive bumps are arranged on the active surface; (b) preparing a circuit substrate, the circuit substrate having a carrying surface, and a soldering pad is disposed on the carrying surface corresponding to each of the conductive bumps; (c) using a 3D array nozzle printing device to spray a soldering flux onto the surface of each of the solder pads, and controlling the spraying range and spraying dosage of the soldering flux through the program setting of the 3D array nozzle printing device; (d) turning over and aligning the chip so that the active surface of the chip faces the supporting surface of the circuit substrate, and each of the conductive bumps is respectively connected to each of the bonding pads via the soldering flux, and then performing a metal welding operation so that the chip is electrically and structurally connected to each of the bonding pads on the circuit substrate via each of the conductive bumps to form a flip chip package structure; (e) filling a liquid material between the circuit substrate and the chip to cover a substance to be cleaned on the circuit substrate; (f) placing the flip chip package structure containing the liquid material in a sealed processing chamber, and heating the processing chamber to a predetermined temperature, wherein the predetermined temperature is in a range of 25 to 200° C. in accordance with the viscosity of the liquid material; (g) intermittently evacuating the gas in the processing chamber with a vacuum generator to generate a wave-like gas flow, which is a fluctuation under vacuum, ranging from a maximum value of no more than 1 atmosphere to a minimum value of 10 -5 The atmospheric pressure fluctuates intermittently, and the fluctuation of the gas vacuum suction force causes the fluctuation of the liquid material, so that the liquid material in contact with the material to be cleaned is rubbed back and forth with a larger amplitude, and the material to be cleaned attached to the circuit substrate is more effectively removed from the circuit substrate.

2. A flip chip packaging process, characterized in that: The steps include: (a) preparing a chip, wherein the chip has an active surface, and a plurality of conductive bumps are arranged on the active surface; (b) preparing a circuit substrate, the circuit substrate having a carrying surface, and a soldering pad is disposed on the carrying surface corresponding to each of the conductive bumps; (c) using a 3D array nozzle printing device to spray a soldering flux onto the surface of each of the solder pads, and controlling the spraying range and spraying dosage of the soldering flux through the program setting of the 3D array nozzle printing device; (d) turning over and aligning the chip so that the active surface of the chip faces the supporting surface of the circuit substrate, and each of the conductive bumps is respectively connected to each of the bonding pads via the soldering flux, and then performing a metal welding operation so that the chip is electrically and structurally connected to each of the bonding pads on the circuit substrate via each of the conductive bumps to form a flip chip package structure; (e) filling a liquid material between the circuit substrate and the chip to cover a substance to be cleaned on the circuit substrate; (f) placing the flip chip package structure containing the liquid material in a sealed processing chamber, and heating the processing chamber to a predetermined temperature, wherein the predetermined temperature is in a range of 25 to 200° C. in accordance with the viscosity of the liquid material; (g) using a pressure increasing and reducing device and a vacuum generator to intermittently increase and decrease the pressure and intermittently evacuate the gas in the chamber to generate a wave-like airflow, which is a fluctuation from high pressure to vacuum, ranging from a maximum of 50 atmospheres to a minimum of 10 -5 The atmospheric pressure fluctuates intermittently, and the fluctuation of the gas is used to cause the fluctuation of the liquid material, so that the liquid material in contact with the material to be cleaned is rubbed back and forth, and the material to be cleaned attached to the circuit substrate is more effectively removed from the circuit substrate.

3. A flip chip packaging process, characterized in that: The steps include: (a) preparing a chip, wherein the chip has an active surface, and a plurality of conductive bumps are arranged on the active surface; (b) preparing a circuit substrate, the circuit substrate having a carrying surface, and a soldering pad is disposed on the carrying surface corresponding to each of the conductive bumps; (c) using a 3D array nozzle printing device to spray a soldering flux onto the surface of each of the solder pads, and controlling the spraying range and spraying dosage of the soldering flux through the program setting of the 3D array nozzle printing device; (d) turning over and aligning the chip so that the active surface of the chip faces the supporting surface of the circuit substrate, and each of the conductive bumps is respectively connected to each of the bonding pads via the soldering flux, and then performing a metal welding operation so that the chip is electrically and structurally connected to each of the bonding pads on the circuit substrate via each of the conductive bumps to form a flip chip package structure; (e) filling a liquid material between the circuit substrate and the chip to cover a substance to be cleaned on the circuit substrate; (f) placing the flip chip package structure containing the liquid material in a sealed processing chamber, and heating the processing chamber to a predetermined temperature, wherein the predetermined temperature is in a range of 25 to 200° C. in accordance with the viscosity of the liquid material; (g) An increasing / decreasing pressure device is used to intermittently increase / decrease the pressure of the gas in the processing chamber to produce a wavy airflow, which fluctuates from high pressure to 1 atmosphere, and intermittently fluctuates between a maximum value of 50 atmospheres and a minimum value of 1 atmosphere. The fluctuating changes of the gas are used to cause the fluctuating changes of the liquid material, so that the liquid material in contact with the material to be cleaned is rubbed back and forth, thereby more effectively removing the material to be cleaned attached to the circuit substrate from the circuit substrate.

4. The flip chip packaging process according to claim 1, 2 or 3, characterized in that: The soldering flux is a liquid soldering flux, and the viscosity of the liquid soldering flux is in the range of 1 centipoise to 100 centipoise.

5. The flip chip packaging process according to claim 1, 2 or 3, wherein: The substance to be cleaned is soldering flux, soldering flux residue, oil ester, photoresist or products generated in the manufacturing process.

6. The flip chip packaging process according to claim 1, 2 or 3, characterized in that: The liquid material is a base glue, which contains hard particles. The hard particles roll back and forth with the fluctuation of the base glue, thereby increasing the friction and scrubbing effect.

7. The flip chip packaging process according to claim 6, wherein: The primer component is epoxy resin.

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