Fluxless Thermocompression Bonding System and Method

Abstract

To provide a fluxless thermocompression bonding system and method preventing metal oxides from being produced before or during a bonding process.SOLUTION: A bonding system for bonding an electronic component to a base member includes a first container for forming a first inert environment where the base member is locatable during bonding of the electronic component. A first plasma cleaning device is located in the first container to clean the electronic component and / or the base member by removing metal oxides therefrom. A second plasma cleaning device is also provided to clean the electronic component by removing organic contaminants from the electronic component before the electronic component is conveyed into the first container. A bond head is movably installed in the first container to bond the electronic component to the base member after the electronic component and / or the base member has been cleaned by the first plasma cleaning device.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to thermocompression bonding, and more particularly to a fluxless thermocompression bonding system and method capable of actively removing impurities such as organic contaminants and metal oxides on an electronic component and a base member to which the electronic component is bonded.

Background Art

[0002] Thermocompression bonding (TCB) is one process capable of performing a flip-chip bonding process. During the bonding process, a die from a silicon wafer is transferred to a bonding head with the bumps on the die facing downward. Next, the die carried by the bonding head is placed at the bonding position of the substrate. Next, a compressive force is applied to the die to press the die against the substrate to ensure good contact between the die and the substrate. As is well known in the art, impurities on the bonding surfaces of the die and the substrate can prevent good contact between them and can ultimately have a significant impact on the performance of the finally bonded package. Impurities include, but are not limited to, organic contaminants covering the bonding surfaces of the die and the substrate, and metal oxides resulting from oxidation of the bonding material and the bonding surfaces before or during the TCB process.

[0003] In one prior art TCB process, a liquid flux can be applied to the bonding surfaces of the die and the substrate to remove the metal oxides thereon before bonding. After the die and the substrate are bonded to each other, a deflux process is performed to remove the flux residues on the final bonded package. However, the application of the flux and the deflux process results in a significant increase in the cost of the bonding process. Further, metal oxides may be generated again before or during the bonding process after the above-described oxide removal process. Further, since the oxide removal process is not suitable for removing organic contaminants, if organic contaminants are present, the quality of the joint between the die and the substrate may still be affected.

[0004] Therefore, it would be beneficial to effectively and substantially remove both metal oxides and organic contaminants on the die and the substrate before bonding the die to the substrate, and to prevent the formation of metal oxides before or during the bonding process.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Accordingly, an object of the present invention is to provide a fluxless thermocompression bonding system and method that effectively removes or reduces both metal oxides and organic contaminants present on an electronic component and a base member before the electronic component is bonded to the base member, and prevents the formation of metal oxides before or during the bonding process. Doing so will help avoid performance degradation of the final bonded package caused by such impurities that may be present on the electronic component and the base member.

Means for Solving the Problems

[0007] According to a first aspect of the present invention, a bonding system for bonding an electronic component such as a die or a chip to a base member such as a substrate is provided. The system includes a first container for forming a first inert gas environment in which the base member can be disposed during the bonding of the electronic component, a first plasma cleaning device that operates to clean the electronic component and / or the base member by removing metal oxides, the first plasma cleaning device being disposed within the first container, a second plasma cleaning device that operates to clean the electronic component by removing organic contaminants before the electronic component is transferred to the first container, and a bonding head that is movably installed within the first container and operates to bond the electronic component to the base member after the electronic component and / or the base member has been cleaned by the first plasma cleaning device.

[0008] According to the bonding system, first, a first cleaning process is performed to remove organic contaminants from the electronic component by the second plasma cleaning device. Then, after the electronic component is transported into the first container, a second cleaning process can be performed to remove metal oxides on the electronic component by the first plasma cleaning device. At the same time, the first plasma cleaning device may be used to clean the base member disposed within the first container before the electronic component is bonded to the base member. Thereby, before the bonding process, the organic contaminants on the electronic component and the metal oxides present on the electronic component and the base member can be effectively removed. Also, since an inert gas environment is formed within the first container, metal oxides are not formed on the electronic component and the base member after the second cleaning process and in the subsequent bonding process within the first container. Thereby, performance degradation of the final bonding package due to impurities present on the electronic component and the base member can be effectively avoided. Thereby, the bonding quality between the electronic component and the base member can be significantly improved.

[0009] The first plasma cleaning device can include a first plasma head arranged and operated to clean electronic components, and a second plasma head arranged and operated to clean a base member. In one embodiment, the first plasma cleaning device may be an integrally formed single-component device, i.e., a dual-head plasma cleaning device including the first plasma head and the second plasma head. Thereby, space can be saved and simultaneous cleaning of the electronic components and the base member can be easily performed. Alternatively, in another embodiment, the first and second plasma heads may be two separate devices that operate independently to clean the electronic components and the base member separately.

[0010] At least one of the first and second plasma heads may be attached to a motion table within a first container so as to be movable to a cleaning position within the first container for cleaning the electronic components and / or the base member. The first and second plasma heads may be attached to a common motion table or different motion tables. The first plasma head may be movable to a first cleaning position where the first plasma head is aligned with an electronic component that can be held by a bonding head or other holding device in order to clean the electronic component with the plasma emitted from the first plasma head. The second plasma head may be movable to a second cleaning position where the second plasma head is aligned with a base member disposed within the first container in order to clean the base member with the plasma emitted from the second plasma head.

[0011] To provide a more compact joining system, the joining head of the joining system may be further configured to pick up and hold an electronic component while a first plasma head is cleaning the electronic component. Thereby, there is no need to separately provide a holding device for holding the electronic component in the first container during cleaning of the electronic component, and the compactness of the first container can be maintained. Further, both the first and second plasma heads may be attached to a common moving table and may move together with the common moving table. Preferably, the first and second plasma heads are configured to be simultaneously positioned at first and second cleaning positions such that when the first plasma head moves to the first cleaning position to clean the electronic component with plasma, the second plasma head simultaneously moves to the second cleaning position to clean the base member with plasma. For example, the first and second plasma heads may be arranged to face each other directly such that when the first discharge end of the first plasma head faces the electronic component held by the joining head, the second discharge end of the second plasma head faces the base member located in the first container.

[0012] Alternatively, the first plasma head may be fixedly attached to a first cleaning position in the first container for cleaning the electronic component. Accordingly, the joining system may further include a holding device configured to hold the electronic component while the first plasma head is cleaning the electronic component. The holding device may operate to clean the electronic component held at the first cleaning position by the holding device by the first plasma head and may be arranged to be aligned with the first plasma head in the first container. A heating member may be coupled to the holding device for heating the electronic component during the cleaning process. This helps to accelerate the cleaning process and improve the efficiency of the first plasma head. The second plasma head may also be fixedly attached to a second cleaning position in the first container for cleaning the base member.

[0013] The bonding system can further include a transfer system configured to transfer the electronic components cleaned by the second plasma cleaning apparatus to the first container and position the electronic components within the first container.

[0014] To improve the performance of the second plasma cleaning apparatus, the bonding system can further include a second container for forming a second inert gas environment, and the second plasma cleaning apparatus is disposed within the second container for cleaning the electronic components when the electronic components are transported into the second container.

[0015] The first container and the second container may communicate with each other via a transport passage so that the electronic components cleaned by the second plasma cleaning apparatus can be transferred from the second container to the first container via the transport passage. A first inert gas diffuser can be installed on the transport passage to form a first fluid curtain within the transport passage to prevent gas fluid communication between the first container and the second container.

[0016] The second container can further include an inlet passage for transporting the electronic components into the second container via the inlet passage. To prevent gas fluid communication between the second container and the surrounding environment outside the second container, a second inert gas diffuser can be installed on the inlet passage to form a second fluid curtain within the inlet passage.

[0017] The bonding system can further include an inert gas sensor disposed within the first container to detect the concentration of the first inert gas environment within the first container. Preferably, the inert gas sensor is installed on the inner wall within the inner chamber of the first container, and the bonding head is movably installed within the inner chamber.

[0018] The bonding system can further include a hydrogen sensor disposed within the first container to detect the hydrogen concentration within the first container and / or an ozone sensor disposed on the second container to detect the leakage of ozone from the second container.

[0019] According to a second aspect of the present invention, there is provided a bonding method for bonding an electronic component to a base member using a bonding system including a bonding head, a first plasma cleaning device, and a second plasma cleaning device, which are arranged in a first inert gas environment formed in a first container. The method includes cleaning the electronic component by removing organic contaminants from the electronic component with the second plasma cleaning device; transporting the electronic component cleaned by the second plasma cleaning device to the first container; cleaning the electronic component and / or the base member by removing metal oxides from the electronic component and / or the base member arranged in the first container with the first plasma cleaning device; and bonding the electronic component to the base member with the bonding head of the bonding system.

[0020] These and other features, aspects, and advantages will be better understood with reference to the description section, the appended claims, and the accompanying drawings.

Brief Description of the Drawings

[0021]

Fig. 1A

Fig. 1B

Fig. 2

Fig. 3A

Fig. 3B

Fig. 4

Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be exemplarily described with reference to the accompanying drawings.

[0023] In the drawings, like parts are denoted by like reference numerals.

[0024] Before describing the embodiments in more detail, first, an overview will be described. Some embodiments provide a configuration in which a bonding head and a first plasma cleaning device are mounted in a first inert environment. The bonding head is configured to bond an electronic component to a base member, and the first plasma cleaning device is configured to clean the electronic component and / or the base member by removing metal oxides before bonding. Thereby, metal oxides on the electronic component and / or the base member can be effectively removed before bonding. Also, the first inert environment can effectively prevent the generation of metal oxides after the removal process and during the bonding process. Further, a second plasma cleaning device for cleaning the electronic component by removing organic contaminants from the electronic component before transporting the electronic component into the first inert environment can also be provided. The first plasma cleaning device may be movably or fixedly mounted in the first inert environment depending on the arrangement of the bonding system within the first inert environment. To accelerate the metal oxide removal process, the electronic component and / or the base member can be heated by a heating member during the removal process.

[0025] FIG. 1A is a schematic side view of a thermocompression bonding system 100 for bonding a die 200 to a substrate 300 according to a first embodiment of the present invention. The bonding system 100 includes a first or main container 110 in which a first inert gas environment is formed, a first plasma cleaning device 130 movably mounted in the main container 110 for removing metal oxides from the die 200 and the substrate 300, a second or secondary container 120, and a second plasma cleaning device 140 mounted in the secondary container 120 for removing organic contaminants from the die 200.

[0026] Referring to FIG. 1A, the main container 110 includes an upper internal chamber 112 for holding the bonding head 101 and a lower internal chamber 114 for holding the bonding stage 122 on which the substrate 300 can be disposed. The upper internal chamber 112 includes a bottom opening configured to allow the bonding head 101 to move towards or away from the substrate 300. The lower internal chamber 114 can include an upper plate 115 having an opening substantially aligned with the bottom opening of the upper internal chamber 112. As a result, the bonding head 101 operates to move downward until the die 200 contacts the substrate 300 during the bonding process. The upper plate 115 may further include a cooling plate.

[0027] The bonding system 100 can further include at least one first inert gas diffuser 113 installed on the main container 110 to form a first inert environment within the main container 110. The first inert gas can include nitrogen and / or other inert gases such as helium and argon. Each first inert gas diffuser 113 is configured to introduce the first inert gas into the main container 110. In this embodiment, there are two first inert gas diffusers 113 attached to the upper surface of the upper internal chamber 112. Alternatively, the first inert gas diffuser 113 may be attached outside the main container 110. The main container 110 can include at least one first inert gas inlet fluidly connected to the first inert gas diffuser 113 to allow the first inert gas from the first inert gas diffuser 113 to enter the main container 110 through the first inert gas inlet. The main container 110 can further include at least one exhaust port 119 for exhausting air within the main container 110, if necessary, for example, when it is necessary to adjust the concentration of the inert gas within the main container 110.

[0028] In this embodiment, the first plasma cleaning device 130 has a dual head including a first plasma head 131 and a second plasma head 132. The first plasma cleaning device 130 is attached to the moving table 116 such that the first and second plasma heads 131, 132 are arranged directly opposite to each other. Specifically, when the first plasma cleaning device 130 is moved by the moving table 116 along a horizontal direction, for example, a direction along the X-axis or Y-axis of the Cartesian coordinate system, the first plasma head 131 is movable to a first cleaning position where the first discharge end of the first plasma head 131 faces the die 200 held by the bonding head 101. Thereby, the die 200 is cleaned by the first plasma head 131 with the plasma discharged from the first discharge end. The second plasma head 132 is movable to a second cleaning position where the second discharge end of the second plasma head 132 faces the substrate 300 located on the bonding stage 122, and the substrate 300 is cleaned by the second plasma head 132 with the plasma discharged from the second discharge end. In this configuration, the first plasma cleaning device 130 can be moved to the cleaning position of the first plasma cleaning device 130 between the die 200 held by the bonding head 101 and the substrate 300 on the bonding stage 122. Thereby, the first and second plasma heads 131, 132 operate to simultaneously clean the die 200 and the substrate 300. The cleaning position of the first plasma cleaning device 130 means that the first plasma head 131 is in the first cleaning position and the second plasma head 132 is in the second cleaning position.

[0029] The first plasma head 131 may be a nozzle-type plasma head including at least one nozzle for discharging plasma toward the die 200 held by the bonding head 101 in order to remove metal oxides on the die 200. The second plasma head 132 can be a point-type plasma head including at least one nozzle for discharging plasma toward the substrate 300 positioned on the bonding stage 122. Alternatively, the first and second plasma heads 131, 132 may be provided with other types of plasma heads, for example, line-type plasma heads. Those skilled in the art should understand that in other embodiments, as long as the two plasma heads 131, 132 operate to effectively remove metal oxides on the die 200 and the substrate 300 respectively, the two plasma heads 131, 132 may be separate devices and may be attached to the same or different moving tables.

[0030] The first plasma cleaning device 130 can use hydrogen as the active gas to remove metal oxides on both the die 200 and the substrate 300. Therefore, the gas in the main container 110 includes a mixture of the active hydrogen gas used in the first plasma cleaning device 130 and an inert gas introduced into the main container 110, for example, nitrogen, helium, argon.

[0031] In order to efficiently and effectively remove metal oxides from the die 200 by the first plasma head 131, the bonding head 101 can further include a heating element 102 for heating the die 200 when removing metal oxides from the die 200 by the first plasma head 131. Similarly, the bonding stage 122 can further include a heating member 111 for heating the substrate when removing metal oxides from the substrate 300 using the second plasma head 132 in order to efficiently and effectively remove metal oxides from the substrate 300.

[0032] The secondary container 120 is configured to form a second inert gas environment in order to improve the performance of the second plasma cleaning device 140 attached to the secondary container 120. The bonding system 100 can further include at least one second inert gas diffuser 123 that supplies a second inert gas into the second container 120 to generate a second inert gas and form a second inert gas environment. The second inert gas diffuser 123 may be installed on the inner wall of the secondary container 120 or outside the secondary container 120. When the second inert gas diffuser 123 is attached outside the second container 120, the second container 120 can further include at least one second inert gas inlet that is fluidly connected to the second inert gas diffuser 123 to allow the second inert gas to enter the second container 120. The second inert gas can include nitrogen or other inert gases. In this embodiment, two second inert gas diffusers 123 are attached to the upper inner surface of the second container 120. The secondary container 120 further includes an inlet passage 124 for transferring the die 200 into the secondary container 120. At least one third inert gas diffuser 125 can be installed in the inlet passage 124 to form a barrier such as a fluid curtain to prevent or at least reduce air communication between the secondary container 120 and the surrounding environment outside the secondary container 120.

[0033] The second plasma cleaning device 140 attached to the secondary container 120 is configured to remove organic contaminants from the die 200 in the secondary container 120 before the die 200 is transferred to the main container 110. In this embodiment, the bonding system 100 can further include a die holding device, namely an arm 121, configured to hold the die 200 such that the bump side of the die 200 faces the second plasma cleaning device 140. In this embodiment, the die holding device 121 is attached to the upper part of the secondary container 120. The second plasma cleaning device 140 is disposed at the lower part of the secondary container 120 and is aligned with the die holding device 121 such that the die 200 held by the die holding device 121 is cleaned by the second plasma cleaning device 140. Thereby, the discharge end of the second plasma cleaning device 140 is opposed to the bump side of the die 200, and the organic contaminants can be removed from the bump side of the die 200 by the plasma discharged from the discharge end of the second plasma cleaning device 140. The second plasma cleaning device 140 can use oxygen as an active gas to remove the organic contaminants on the die 200. Therefore, the gas in the secondary container 120 includes a mixture of the active gas oxygen that has entered the secondary container 120 and the second inert gas. The organic contaminants on the die 200 include, but are not limited to, organic residues on the surface of the interconnecting portions of the die 200, such as solder bumps or metal pillars of the die 200. Typically, the metal pillars may include pillars of copper, nickel, or gold. Note that the configurations of the second plasma cleaning device 140 and the die holding device 121 are for illustrative purposes and do not limit the scope of the present invention. In other embodiments, these devices may be arranged in different ways. For example, the die holding device 121 may be disposed at the lower part of the secondary container 120, and the second plasma cleaning device 140 may be attached to the upper part of the secondary container 120 and aligned with the die holding device 121. In a specific embodiment, the die holding device 121 or the second plasma cleaning device 140 may be movably installed in the secondary container 120.As a result, the die 200 held by the die holding device 121 can be aligned with the second plasma cleaning device 140 before starting the second plasma cleaning device 140 for cleaning. For example, the die holding device 121 or the second plasma cleaning device 140 may be mounted on the moving table in some cases.

[0034] The bonding system 100 may further include a transport passage 150 configured to connect the main container 110 and the secondary container 120. The transport passage 150 is arranged to enable the die 200 to be transferred from the secondary container 120 to the main container 110 by the transfer system 160. To avoid or reduce gas communication between the first chamber and the second chamber, at least one additional inert gas diffuser 151 can be installed in the transport passage 150 to form a fluid curtain along the transport passage 150. The transfer system 160 may include a movable die transfer arm configured to transfer the die 200 from the secondary container 120 to a predetermined position within the main container 110, where the bonding head 101 operates to pick up the die 200 from the transfer system 160. When the die 200 is received by the transfer system 160 from the die holding device 121, the bump side of the die 200 contacts the transfer system 160, and when the bonding head 101 picks up the die 200 from the transfer system 160, the bump side of the die 200 faces downward again.

[0035] The bonding system 100 may further include an inert gas sensor 117 disposed in the upper inner chamber 112 to detect the concentration or ppm level of the first inert gas environment within the main container 110. The inert gas sensor 117 may be installed on the inner surface of the upper inner chamber 112. Referring to FIG. 1, the inert gas sensor 117 may preferably be disposed near the bottom opening of the upper inner chamber 112. The exhaust port 119 of the main container 110 can be used to discharge excess inert gas from the main container 110 when the inert gas sensor 117 detects that the ppm level of the first inert gas environment has exceeded a predetermined level.

[0036] To confirm that the concentration of the active hydrogen gas does not exceed a predetermined safety level, a hydrogen sensor 118 for detecting the hydrogen concentration in the main container 110 may be further installed in the main container 110. Further, the bonding system 100 may further include an ozone sensor 126 disposed on the secondary container 120 to detect any leakage of ozone (O3) from the secondary container 120.

[0037] FIG. 1B is a schematic plan view of a transfer system 160 of the bonding system 100 according to the first embodiment of the present invention. As shown in FIG. 1B, the transfer system 160 can include a die transfer arm (DTA) 161, a die feeder 162, and a die pick arm (DPA) 163. In this embodiment, the die holding device 121 can be mounted on a moving table that enables the die 200 to be moved to a position directly aligned with the second plasma cleaning device 140. When the second plasma cleaning device 140 cleans the die 200, the die holding device 121 operates to transfer the cleaned die 200 to the die feeder 162. The die feeder 162 is configured to receive the die 200 cleaned by the second plasma cleaning device 140 from the die holding device 121. The die 200 is disposed on the die feeder 162 such that its bump / front surface contacts the die feeder 162. Next, the DPA 163 is operated to pick up the die 200 from the die feeder 162, and the bump side of the die 200 is brought into contact with the pad of the DTA 161 to transfer the die 200 to the pad. The DTA 161 operates to move the die 200 to a predetermined position, whereby the bonding head 101 operates to pick up the die 200 from the DTA 161. Next, before the step of removing the metal oxide on the die 200 using the first plasma head 131 of the first cleaning device 130, the bonding head 101 is operated to pick up the die 200 from the DTA 161 with the bump side of the die 200 facing downward.

[0038] FIG. 2 is a flowchart showing a thermocompression bonding method 20 for bonding a die 200 to a substrate 300 using a bonding system 100 according to a first embodiment of the present invention.

[0039] In step 201, with the bump side of the die 200 facing down, the die 200 is transferred and held in the secondary container 120 by the die holding device 121, and the bump side of the die 200 is cleaned by the second plasma cleaning device 140 in the secondary container 120 to remove organic contaminants from the bump side of the die 200.

[0040] Referring to FIG. 1B, the die 200 is held by the die holding device 121, whereby the second plasma cleaning device 140 can emit plasma toward the bump side of the die 200 to remove organic contaminants from the die 200. Alternatively, the die holding device 121 can be replaced with a die support stage on which the die 200 can be placed. In this setting, the second plasma cleaning device 140 may be arranged directly above the die support stage and configured to emit plasma downward toward the bump side of the die 200. Further, the die holding device 121 is installed on a moving table and can move the die 200 to a position directly aligned with the second plasma cleaning device 140 before the cleaning process starts.

[0041] In step 202, the second plasma cleaning device 140 is operated to remove organic contaminants from the die 200 in the secondary container 120. The active gas used by the second plasma cleaning device 140 contains oxygen.

[0042] In step 203, the die 200 is transferred from the secondary container 120 to the main container 110 by the transfer system 160 and picked up by the bonding head 101 from the transfer system 160.

[0043] Specifically, in this embodiment, referring to FIG. 1B, the transfer system 160 can include a DTA 161, a die feeder 162, and a DPA 163. After the die 200 is cleaned by the second plasma cleaning apparatus 140, the die holding device 121 can be further moved to transfer the die 200 to the die feeder 162. The die 200 can be placed on the die feeder 162 such that its bump side contacts the die feeder 162. Next, the die 200 is picked up from the die feeder 162 by the DPA 163. The DPA 163 operates to contact the bump side of the die 200 with the pad and transfer the die 200 to the pad of the DTA 161. Next, the DTA 161 moves the die 200 to a predetermined position directly below the bonding head 101, and operates the bonding head 101 to pick up the die 200 from the DTA 161 with the bump side of the die 200 facing downwards.

[0044] In step 204, the first plasma cleaning apparatus 130 is moved to the cleaning position by the moving table 116 and operated to simultaneously remove metal oxides from the die 200 and the substrate 300. The cleaning position may be arranged to be aligned with the die 200 and the substrate 300 such that the first plasma head 131 operates to clean the die 200 and the second plasma head 132 operates to clean the substrate 300.

[0045] In step 205, the bonding head 101 bonds the die 200 to the substrate 300 within the main container 110.

[0046] In the first embodiment, the first plasma cleaning apparatus 130 is movable such that it can perform the metal oxide cleaning process while the die 200 is held by the bonding head 101. Alternatively, in other embodiments, the first plasma cleaning apparatus 130 or at least one plasma head of the first plasma cleaning apparatus 130 may be fixedly installed within the main container 110, and the die 200 may be movable to a predetermined position for removing metal oxides by the first plasma head 131 of the first plasma cleaning apparatus 130.

[0047] FIG. 3A is a schematic cross-sectional view of a thermocompression bonding system 100A for bonding a die 200 to a substrate 300 according to a second embodiment of the present invention. Similar to the bonding system 100, the bonding system 100A includes a main container 110, a secondary container 120, a first plasma cleaning device 130 attached to the main container 110, and a second plasma cleaning device 140 attached to the secondary container 120. The main structural differences between the bonding system 100A and the bonding system 100 are that the arrangement of the first plasma cleaning device 130 is different and an additional die holding device 119 is provided in the main container 110. Further, the bonding system 100A also includes a transfer system 160A that transfers the die 200 from the secondary container 120 to the main container 110 and positions the die 200 within the main container 110. The function of the transfer system 160A is slightly different from that of the transfer system 160 of the first embodiment.

[0048] Referring to FIG. 3A, in this embodiment, the first plasma cleaning device 130 includes a first plasma head 131A and a second plasma head 132A fixedly attached within the main container 110. The die holding device 119 is positioned so as to be aligned with the first plasma head 131A such that the die 200 held by the die holding device 119 is cleaned by the first plasma head 131A.

[0049] The transfer system 160A is configured to transfer the die 200 from the secondary container 120 to the main container 110 and position the die 200 at a first predetermined position. This position enables the die holding device 119 to pick up the die 200 from the transfer system 160A before the first plasma head 131A operates to remove metal oxide from the die 200. The die holding device 119 is installed on a moving table and can be moved to the first predetermined position to pick up the die 200 from the transfer system 160A. After the die holding device 119 picks up the die 200, the die 200 can be cleaned using the first plasma head 131A. When the cleaning process is completed, the die holding device 119 operates to return the die 200 to the transfer system 160A. The first predetermined position may be directly below the die holding device 119 or directly above the first plasma head 131A.

[0050] The die holding device 119 can further include a heating member 119a configured to heat the die 200 when the die 200 is cleaned by the first plasma head 131A. The heating member 119a may be further used to activate the surface of the die 200. The second plasma head 132A can be fixedly attached inside the lower part of the main container 110 to remove metal oxide from the substrate 300 before the die 200 is bonded to the substrate 300. Preferably, the second plasma head 132A may be coupled to the upper plate 115 of the lower internal chamber 114, such as a cooling plate of the upper plate 115.

[0051] After the die 200 is cleaned by the first plasma head 131A, the die 200 is further transferred to a second predetermined position by the transfer system 160A. As a result, the bonding head 101 can pick up the die 200 from the transfer system 160A and bond the die 200 to the substrate 300. Preferably, the second predetermined position is directly below the bonding head 101. Different from the first embodiment, the bonding head 101 in the second embodiment is not used to hold the die 200 during the process of removing metal oxides from the die 200. The dashed arrows indicate the possible transfer paths of the die 200 during the entire process.

[0052] Figure 3B is a schematic plan view of the transfer system 160A of the bonding system 100A according to the second embodiment of the present invention. Referring to Figure 3B, the transfer system 160A can include a die feeder 162A, a DPA 163A, and a DTA 161A. The die feeder 162A is configured to receive the die 200 in a state where the bump side of the die contacts the die feeder 162A after the die 200 is cleaned by the second plasma cleaning device 140. The DPA 163A operates to take out the die 200 from the die feeder 162A with the bump side of the die 200 in contact with the first pad P1 and transfer the die 200 to the first pad P1 of the DTA 161A. The DTA 161A moves the die 200 to a first predetermined position and moves the die holding device 119 to the first predetermined position to pick up the die 200 from the first pad P1 of the DTA 161A with the bump side of the die 200 facing down. Next, the die holding device 119 is moved to a position directly aligned with the first plasma head 131A. After the die 200 is cleaned by the first plasma head 131A, the die holding device 119 moves to place the die 200 on the second pad P2 of the DTA 161A. Next, the DTA 161A operates to transfer the die 200 to a second predetermined position below the bonding head 101 so that the die 200 can be picked up from the DTA 161A by the bonding head 101.

[0053] FIG. 4 is a flowchart showing a thermocompression bonding method 40 for bonding die 200 to substrate 300 according to a second embodiment of the present invention.

[0054] In step 401, the die 200 is transferred and held in the secondary container 120 by the die holding device 121 with the bump side of the die 200 facing down so that the organic contaminants on the bump side of the die 200 can be removed by the second plasma cleaning device 140.

[0055] Referring to FIG. 3B, the die 200 is held by the die holding device 121 so that the second plasma cleaning device 140 can emit plasma toward the bump side of the die 200 to remove the organic contaminants thereon.

[0056] In step 402, the second plasma cleaning device 140 is operated to remove the organic contaminants on the die 200. The active gas used by the second plasma cleaning device 140 contains oxygen.

[0057] In step 403, the die 200 is transferred from the secondary container 120 to the main container 110, positioned at a first predetermined position by the transfer system 160A, and the die holding device 119 is operated to pick up the die 200 from the transfer system 160A.

[0058] Specifically, in the present embodiment, after the die 200 is cleaned by the second plasma cleaning device 140, the die 200 is transferred and placed on the die feeder 162A by the die holding device 119 in a state where the bump side of the die is in contact with the die feeder 162A. Then, the DPA 163A takes out the die 200 from the die feeder 162A and transfers the die 200 to the first pad P1 while bringing the bump side of the die 200 into contact with the first pad P1 of the DTA 161A. Next, the DTA 161A moves the die 200 to a first predetermined position, and the die holding device 119 picks up the die 200 from the DTA 161A with the bump side of the die 200 facing down. After cleaning the die 200 by the first plasma head 131, the die holding device 119 is further operated to place the die 200 on the second pad P2 of the DTA 161A. Next, the DTA 161A is operated to move the die 200 to a second predetermined position under the bonding head 101, and the bonding head 101 picks up the die 200 from the DTA 161A and operates to hold the die 200 during the subsequent bonding process. The first predetermined position may be directly below the die holding device 119 or directly above the first plasma head 131A.

[0059] It should be noted that the embodiments of the transfer systems 160 and 160A shown in FIGS. 2B and 3B are for illustrative purposes only and are not intended to limit the scope of the present invention. In other embodiments, the transfer system 160 or 160A can include different devices and can be arranged in different ways.

[0060] In step 404, the first plasma head 131A operates to remove metal oxides from the die 200.

[0061] In a specific embodiment, the die holding device 119 may be moved to a position directly aligned with the first plasma head 131A before the first plasma head 131A is activated to clean the die 200.

[0062] In step 405, the second plasma head 132 operates to remove metal oxides from the substrate 300.

[0063] In this embodiment, the step of removing metal oxides from the substrate 300 is performed after the step of removing metal oxides from the die 200. However, in other embodiments, the two steps may be performed simultaneously, or the step of removing metal oxides from the substrate 300 may be performed before the step of removing metal oxides from the die 200. The substrate 300 may be further cleaned by the second plasma head 132A at any point before the bonding process.

[0064] In step 406, the die transfer system 160A transfers the die 200 to the bonding position directly below the bonding head 101 and operates the bonding head 101 to pick up the die 200 from the die transfer system 160A.

[0065] In step 407, the bonding head 101 operates to bond the die 200 to the substrate 300 in the main container.

[0066] Various modifications are possible to the embodiments described above. In some embodiments, the bonding system may not include a second container for forming a second inert environment. In some embodiments, the bonding head is installed at the lower part of the main container, the substrate is held by a holding device attached to the upper part of the main container, and accordingly, the functions of the first plasma cleaning device and the transfer device are changed to execute the cleaning process in the main container. Different numbers of inert gas diffusers may be provided in the main container, the secondary container, the transfer passage between them, or the inlet passage of the secondary container. In some embodiments, the transfer system may include different devices arranged in different ways according to the arrangement of the first and second containers and the devices therein. The first and second inert environments can be formed using the same inert gas or a mixture of different inert gases.

[0067] The invention described in this specification can be modified, corrected and / or added with variations, corrections and / or additions other than those specifically described, and it should be understood that the present invention includes all such variations, corrections and / or additions within the spirit and scope of the above description.

Claims

1. A bonding system for bonding an electronic component to a base member, comprising: a first container for forming a first inert gas environment in which the base member can be placed during bonding of the electronic component; a first plasma cleaning device disposed within the first container and operative to clean the electronic component and / or the base member by removing metal oxides from the electronic component and / or the base member; a second plasma cleaning device operative to clean the electronic component by removing organic contaminants from the electronic component before the electronic component is transferred to the first container; a bonding head movably installed within the first container and operative to bond the electronic component to the base member after the electronic component and / or the base member has been cleaned by the first plasma cleaning device; A bonding system comprising the above components.

2. The bonding system according to claim 1, wherein the first plasma cleaning device comprises a first plasma head disposed and operative to clean the electronic component, and a second plasma head disposed and operative to clean the base member.

3. The bonding system according to claim 2, wherein at least one of the first and second plasma heads is attached to a moving table within the first container so as to be movable to a cleaning position within the first container for cleaning the electronic component and / or the base member.

4. The bonding system according to claim 3, wherein the bonding head is further configured to hold the electronic component while the first plasma head is cleaning the electronic component.

5. The bonding system according to claim 3, wherein the first and second plasma heads are attached to the moving table such that when the first plasma head is moved to a first cleaning position aligned with the electronic component for cleaning the electronic component, the second plasma head is simultaneously moved to a second cleaning position aligned with the base member disposed within the first container.

6. The bonding system according to claim 2, wherein the first plasma head is fixedly attached to a first cleaning position within the first container for cleaning the electronic component.

7. The bonding system according to claim 6, further comprising a holding device configured to hold the electronic component when the first plasma head is cleaning the electronic component, the holding device operating to clean the electronic component held at the first cleaning position by the holding device by the first plasma head, and being arranged to be aligned with the first plasma head.

8. The bonding system according to claim 7, further comprising a heating member for heating the electronic component when the first plasma head is cleaning the electronic component, the heating member being coupled to the holding device.

9. The bonding system according to claim 2, wherein the second plasma head is fixedly attached to a second cleaning position in the first container for cleaning the base member.

10. The bonding system according to claim 1, further comprising a transfer system configured to transfer the electronic component cleaned by the second plasma cleaning device to the first container and position the electronic component in the first container.

11. The bonding system according to claim 10, further comprising a second container for forming a second inert gas environment, the second plasma cleaning device being disposed in the second container for cleaning the electronic component when the electronic component is transported to the second container.

12. The bonding system according to claim 11, wherein the first container and the second container are in communication with each other via a transport passage for enabling the electronic component cleaned by the second plasma cleaning device to be transferred from the second container to the first container via the transport passage.

13. The bonding system according to claim 12, further comprising a first inert gas diffuser installed on the transport passage, and forming a first fluid curtain in the transport passage to prevent fluid communication of gas between the first container and the second container.

14. The second container includes an inlet passage through which the electronic component is conveyed into the second container, and a second inert gas diffuser installed on the inlet passage to form a second fluid curtain in the inlet passage to prevent fluid communication of gas between the second container and the surrounding environment outside the second container. The bonding system according to claim 13 further comprises the second inert gas diffuser.

15. The bonding system according to claim 1, further comprising an inert gas sensor disposed in the first container to detect the concentration of the first inert gas environment in the first container.

16. The bonding head is movably installed in an internal chamber located in the first container, and the inert gas sensor is installed on the inner wall in the internal chamber. The bonding system according to claim 15.

17. The bonding system according to claim 1, further comprising a hydrogen sensor disposed in the first container to detect the hydrogen concentration in the first container.

18. The bonding system according to claim 11, further comprising an ozone sensor disposed on the second container to detect leakage of ozone from the second container.

19. A bonding method for bonding an electronic component to a base member using a bonding system including a bonding head, a first plasma cleaning device, and a second plasma cleaning device, wherein the first plasma cleaning device is disposed in a first inert gas environment formed in a first container, and the method includes: cleaning the electronic component by removing organic contaminants from the electronic component with the second plasma cleaning device; conveying the electronic component cleaned by the second plasma cleaning device to the first container; cleaning the electronic component and / or the base member by removing metal oxides from the electronic component and / or the base member disposed in the first container with the first plasma cleaning device; bonding the electronic component to the base member with the bonding head; and the method includes the above steps.

Images