Wafer level flux cleaning apparatus and method

Abstract

The application relates to the technical field of wafer cleaning equipment, and relates to a wafer-level flux cleaning device and a cleaning method, in particular to a wafer-level flux cleaning device which comprises a bearing table, a cleaning frame movably arranged on the upper side of the bearing table; a cleaning pipeline is arranged on the cleaning frame, a plurality of nozzles are arranged on the cleaning pipeline, and the cleaning pipeline is circumferentially rotationally arranged on the cleaning frame so as to adjust the included angle between the nozzles and the bearing table. The application has the following beneficial effects: the relative motion relationship between the two is changed, the cleaning frame is arranged to move, so that the wafer on the bearing table can be cleaned only by moving the cleaning frame; in order to better clean the flux, the cleaning pipeline is arranged to rotate, so as to adjust the liquid spraying angle of the nozzles, and the flux can be cleaned through adjustment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wafer cleaning equipment, in particular to a wafer-level flux cleaning device and a cleaning method. BACKGROUND

[0002] In chip packaging, copper pillar tin-based alloy solder blocks are often used as soldering materials for solder pads. However, the tin-based alloy is often affected by the soldering effect due to the existence of an oxide layer on the surface. Therefore, before reflow soldering, the tin-based alloy solder block needs to be immersed in flux to remove the surface oxide. However, after the reaction between the flux and the surface oxide of the tin-based alloy, there is residual flux, which can cause a series of problems such as poor electrical contact, soldering holes, and substrate corrosion in subsequent processes. Therefore, an additional process step is needed to remove the flux.

[0003] At present, in the cleaning process, the wafer is placed on the bearing table, and the bearing table is moved to the high-pressure cleaning liquid to remove the flux. However, in the actual cleaning process, the position of the flux is not completely exposed or there are more fluxes in the local position. In the ordinary cleaning process, there is often residual flux, and the cleaning effect is poor. SUMMARY

[0004] In order to improve the cleaning effect of the flux, the present application provides a wafer-level flux cleaning device and a cleaning method.

[0005] In the first aspect, the present application provides a wafer-level flux cleaning device, which adopts the following technical solution: a wafer-level flux cleaning device, comprising a bearing table, a cleaning frame movably arranged on the upper side of the bearing table;

[0006] A cleaning pipeline is arranged on the cleaning frame, a plurality of nozzles are arranged on the cleaning pipeline, and the cleaning pipeline is circumferentially rotatably arranged on the cleaning frame to adjust the included angle between the nozzles and the bearing table.

[0007] By adopting the above technical solution, the relative motion relationship between the two is changed, the cleaning frame is arranged to move, so that the wafer on the bearing table can be cleaned only by moving the cleaning frame. In order to better clean the flux, the cleaning pipeline is arranged to rotate to adjust the liquid angle of the nozzles. The flux can be cleaned by adjusting. In addition, when the cleaning liquid and the bearing table form an oblique angle, the horizontal direction can be increased. The impurities cleaned can be better removed, and the cleaning intensity can also be increased. Finally, the position of the wafer on the bearing table will not be changed. The wafer itself is equivalent to not moving, which is convenient for subsequent positioning and operation.

[0008] Preferably, a limiting sleeve is arranged on the cleaning frame and located at two ends of the cleaning pipeline, one end of the cleaning pipeline is sleeved in the limiting sleeve, and a driving wheel for contacting and rotating the cleaning pipeline is rotatably arranged on the cleaning frame.

[0009] By adopting the technical scheme, the driving wheel contacts the outer wall surface of the cleaning pipeline in a rotating manner, can be arranged in gear engagement or directly abutted, and then drives the cleaning pipeline to rotate under the limitation of the limiting sleeve.

[0010] Preferably, a shielding ring is movably arranged on the cleaning pipeline, the shielding ring is used for blocking the liquid outlet of the nozzle, and a driving member for driving the shielding ring to rotate is arranged on the cleaning pipeline.

[0011] By adopting the technical scheme, the wafers on the bearing table also have a certain arrangement rule, for example, the arrangement of the wafers along the circular arc direction at the edge portion of the bearing table is still along the radial direction, that is, there is a vacancy, therefore, when the nozzle moves to the portion where no wafer is placed, the nozzle is blocked by the shielding ring, and the portion where the wafer exists is sprayed, which is used for reducing the influence of the cleaning liquid on the wafer at the non-positively-against wafer position and saving the cleaning liquid.

[0012] Preferably, each nozzle corresponds to one shielding ring, and each shielding ring rotates independently.

[0013] By adopting the technical scheme, the shielding ring corresponds to the nozzle one by one and is controlled independently.

[0014] Preferably, the driving member comprises a driving rod rotatably connected to the cleaning pipeline and a driving gear arranged on the driving rod, and the shielding ring is provided with a tooth groove for engaging with the driving gear.

[0015] By adopting the technical scheme, when the driving rod rotates, the shielding ring performs a loop motion on the cleaning frame through the cooperation of the driving gear and the tooth groove, and then forms the blocking.

[0016] Preferably, the shielding ring has a circular-arc-shaped open hole.

[0017] By adopting the technical scheme, the length of the arc line of the different open holes can be adjusted to adjust the nozzle to spray in a certain movement path, so that the above-mentioned effect is achieved.

[0018] Preferably, the shielding ring comprises two annular frames and a combined arc-shaped piece arranged at intervals, the annular frames are rotatably arranged on the cleaning frame, and the combined arc-shaped piece covers the gap between the annular frames to form the open hole.

[0019] By adopting the technical scheme, the position adjustment of the combined arc pieces can adjust the open hole, and then the overall liquid spray range can be adjusted.

[0020] Preferably, an adjusting rod is rotationally connected between the overlapping portions of the two combined arc pieces, and the adjusting rod contacts opposite sides of the two combined arc pieces to drive the two combined arc pieces to move.

[0021] By adopting the technical scheme, the end portions of the two combined arc pieces are close to each other, the overlapping portion is increased, and then the length of the open hole is increased, and vice versa, so as to achieve the adjusting purpose.

[0022] In a second aspect, the application provides a cleaning method of a wafer-level flux cleaning device, which adopts the following technical scheme: a cleaning method of a wafer-level flux cleaning device according to any one of claims 1-9, S1: adjusting the angle of the nozzle relative to the support table; S2: adjusting the relative height of the nozzle relative to the support table; and S3: moving the cleaning frame to make the cleaning pipeline translate relative to the support table.

[0023] In summary, the application has at least one of the following beneficial technical effects:

[0024] 1. First, change the relative motion relationship between the two, set the cleaning frame to move, so that only the cleaning frame needs to be moved to clean the wafer on the support table, and in order to better clean the flux, set the cleaning pipeline to rotate to adjust the liquid spray angle of the nozzle, so that the flux can be cleaned by adjusting;

[0025] 2. In addition, when the cleaning liquid and the support table form an oblique angle, the horizontal direction can increase the component force, and then the impurities cleaned can be better removed, and of course the cleaning intensity can be increased;

[0026] 3. Finally, the wafer on the support table will not change the original position, which is equivalent to the wafer itself not moving, so that subsequent positioning and operation are facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a schematic view of a wafer fixed on a support table;

[0028] Figure 2 is a structural schematic view of embodiment 1 of the application;

[0029] Figure 3 is a partial structural schematic view of embodiment 1 of the application;

[0030] Figure 4 is a structural schematic view of embodiment 3 of the application;

[0031] Figure 5is a schematic view of a partial structure in which the cleaning frame is hidden in Embodiment 3 of the present application;

[0032] Figure 6 is a schematic view of an internal structure of the shielding ring in Embodiment 3 of the present application, in which the ring-shaped frame on one side is hidden.

[0033] Legend: 100, bearing table; 110, cleaning frame; 111, cleaning pipeline; 112, nozzle; 113, limiting sleeve; 114, driving wheel; 120, shielding ring; 121, ring-shaped frame; 122, combined arc-shaped piece; 123, open hole; 140, driving rod; 141, driving gear; 143, adjusting rod. DETAILED DESCRIPTION

[0034] The present application will be further described in detail below with reference to the accompanying drawings. Embodiment 1

[0035] The present application discloses a wafer-level flux cleaning device, referring to Figure 1 , Figure 2 , which comprises a bearing table 100, and a wafer is adsorbed and fixed on the upper side of the bearing table 100. The bearing area is circular, and the wafers are arranged in an array on the upper side. Specifically, there will be a non-circular edge in the edge part of the circle. Due to the positional relationship of the wafers, there will be a rectangular position missing condition, for example, the end part of the two adjacent rows of wafers will be missing one, which leads to different number of wafers in each row.

[0036] Referring to Figure 2 , Figure 3 , a cleaning frame 110 is movably arranged on the upper side of the bearing table 100. Specifically, the cleaning frame 110 is arranged on the bearing table 100 through a slide rail, and can slide in XYZ axes to adjust the position.

[0037] The cleaning frame 110 is provided with a cleaning pipeline 111, and a plurality of nozzles 112 are arranged on the cleaning pipeline 111. High-pressure cleaning liquid is introduced into the cleaning pipeline 111, and the nozzles 112 are uniformly distributed on the cleaning pipeline 111. In the present embodiment, the length of the cleaning pipeline 111 is 160 mm, and in other embodiments, the length is adapted to the overall size of the bearing table 100.

[0038] The cleaning pipe 111 is arranged on the cleaning frame 110 in a circumferential direction to adjust the included angle between the nozzle 112 and the bearing table 100, and the rotation axis is parallel to the arrangement line of the wafer. The cleaning frame 110 has a limiting sleeve 113 corresponding to the two ends of the cleaning pipe 111, the end of the cleaning pipe 111 is embedded in the limiting sleeve 113, and a driving wheel 114 is also arranged on the cleaning frame 110 and is driven by a motor. The driving wheel 114 can be a gear or a direct contact wheel, which is matched with the outer wall of the cleaning pipe 111 and is provided with a corresponding gear slot or directly contacted to drive the cleaning pipe 111 to rotate in the circumferential direction (the gear slot is not shown in the figure). Embodiment 2

[0039] Based on the wafer-level flux cleaning device of embodiment 1, the embodiment discloses a cleaning method, S1: adjusting the angle of the nozzle 112 relative to the bearing table 100, so that the position of the cleaning frame 110 above is above the bearing table 100;

[0040] S2: adjusting the relative height of the nozzle 112 relative to the bearing table 100, adjusting the liquid spraying angle of the nozzle 112 through the driving wheel 114, and of course, the synchronous adjustment can also be performed during cleaning;

[0041] S3: moving the cleaning frame 110 to make the cleaning pipe translate relative to the bearing table 100. It is worth noting that during the cleaning process, the cleaning can be performed back and forth along two mutually perpendicular diameter directions to improve the overall cleaning effect.

[0042] Such a cleaning method first changes the relative motion relationship between the two, sets the cleaning frame 110 to move, so that only the movement of the cleaning frame 110 can clean the wafer on the bearing table 100. When the cleaning liquid forms an inclined angle with the bearing table 100, the component force in the horizontal direction can be increased, and the impurities cleaned can be better removed, and the cleaning intensity can also be increased. Finally, the position of the wafer on the bearing table 100 will not be changed, which is equivalent to that the wafer itself does not move, so that subsequent positioning and operation are facilitated. Embodiment 3

[0043] The difference between embodiment 1 and embodiment 3 is that, referring to Figure 4 , Figure 5 In the embodiment, the cleaning pipe 111 is also movably provided with a shielding ring 120. Specifically, each nozzle 112 corresponds to one shielding ring 120. The shielding ring 120 is a ring-shaped sheet body, and has an arc-shaped open hole 123 on the circumferential extension surface. When the shielding ring 120 rotates, part of the front side of the nozzle 112 will be shielded, so that the liquid sprayed by part of the nozzles 112 will not wash the bearing table 100.

[0044] The effect of the shield is that it is adapted to the arrangement of the wafers, for example for a queue of wafers on the diameter of the support table 100, the movement direction of the cleaning rack 110 will be perpendicular to the queue of wafers, and when it is just moved to the support table 100, the number of wafers to be flushed is small, at this time the shield ring 120 at both ends of the cleaning pipe 111 is in a state of shielding the nozzle 112, only the middle part of the wafers is flushed. At the same time, the shield ring 120 is continuously rotating, when the open hole 123 moves in front of the nozzle 112, it can flush the wafers, and after the cleaning pipe 111 moves past the longest row of wafers, the movement of the shield ring 120 will make the nozzles 112 at both ends close again, so that all the wafers are adaptively cleaned. The reason for cleaning is to spray liquid on the part where the wafers exist, on the one hand, in order to reduce the influence of the cleaning liquid on the wafers that are not directly opposite, and on the other hand, in order to save the cleaning liquid.

[0045] In this embodiment, an inductive switch, such as an infrared inductive switch, can be installed at the front end of the nozzle 112, and when the shield ring 120 blocks the nozzle 112, the nozzle 112 is closed and does not spray liquid. Alternatively, the shield ring 120 only blocks, and the washing liquid will flow downward, at this time a receiving groove is placed under the cleaning pipe 111 to collect excess cleaning liquid.

[0046] A driving member for driving the shield ring 120 to rotate is arranged on the cleaning pipe 111, wherein the driving member can be selected as a plurality of motors to directly drive the individual shield ring 120 to rotate. Alternatively, the same driving member can be used for driving, and in this embodiment, the same driving member is used as an example, the driving member includes a driving rod 140 rotatably connected to the cleaning pipe 111, and a driving gear 141 arranged on the driving rod 140. The shield ring 120 is provided with a tooth groove (not shown in the figure, only for illustration) for engaging with the driving gear 141. During cleaning, the shield ring 120 will continuously rotate.

[0047] In order to achieve the above effect, the extension length of the open hole 123 in the length direction of the cleaning pipe 111 needs to be different, simply speaking, the open holes 123 at both ends are shorter, and the middle one is longer. If necessary, the shield ring 120 in the middle part is not all open holes 123, but has a certain closed area, in order to close the nozzle 112 when entering and leaving the upper part of the support table 100.

[0048] Reference Figure 5 , Figure 6Therefore, in order to cope with wafers of different sizes or arrangements, the open hole 123 on the shielding ring 120 is adjustable. Specifically, the shielding ring 120 includes two annular frames 121 and combined arc-shaped pieces 122 arranged at intervals. The annular frames 121 are rotatably arranged on the cleaning frame 110. The annular frames 121 are provided with the above-mentioned tooth grooves (not shown in the figure) to cooperate with the driving member.

[0049] The combined arc-shaped pieces 122 cover the gap between the annular frames 121 to form the open hole 123. The combined arc-shaped pieces 122 have two parts that partially overlap and slide along the arc in opposite directions to adjust the length of the open hole 123. The overlapping parts of the two combined arc-shaped pieces 122 are rotatably connected by an adjusting rod 143. The adjusting rod 143 contacts the opposite sides of the two combined arc-shaped pieces 122 to drive the two combined arc-shaped pieces 122 to move. In this embodiment, the adjusting rod 143 is driven by a motor. The adjusting rod 143 can be provided with teeth or directly contact the combined arc-shaped pieces 122 to drive the combined arc-shaped pieces 122 to move along the arc direction and adjust.

[0050] The embodiments of the specific implementation are the preferred embodiments of the present application, but do not limit the protection scope of the present application. Therefore, any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A wafer level flux cleaning apparatus comprising a carrier table (100), characterized in that: The cleaning frame (110) is movably arranged on the upper side of the bearing table (100); The cleaning frame (110) is movably arranged on the upper side of the bearing table (100); The cleaning pipeline (111) is movably arranged with a shielding ring (120), the shielding ring (120) is used to block the nozzle (112) spray port, the cleaning pipeline (111) is provided with a driving member for driving the shielding ring (120) to rotate, the shielding ring (120) has a circular arc-shaped open hole (123); The shielding ring (120) comprises two annular frames (121) and a combined arc-shaped sheet (122) arranged at intervals, the annular frame (121) is rotatably arranged on the cleaning frame (110), and the combined arc-shaped sheet (122) covers the gap between the annular frames (121) to form the open hole (123); The combined arc-shaped sheet (122) has two, two of the combined arc-shaped sheets (122) partially overlap and slide along the arc in opposite directions to adjust the length of the open hole (123) extending.

2. The wafer level flux cleaning apparatus of claim 1, wherein: The cleaning frame (110) is movably arranged on the upper side of the bearing table (100); 3. The wafer level flux cleaning apparatus of claim 1, wherein: Each of the nozzles (112) corresponds to a shielding ring (120), and each of the shielding rings (120) rotates independently.

4. The wafer level flux cleaning apparatus of claim 1, wherein: The driving member comprises a driving rod (140) rotatably connected to the cleaning pipeline (111) and a driving gear (141) arranged on the driving rod (140), and the shielding ring (120) is provided with a tooth groove for engaging with the driving gear (141).

5. The wafer level flux cleaning apparatus of claim 1, wherein: The two overlapping parts of the combined arc-shaped sheet (122) are rotatably connected with an adjusting rod (143), and the adjusting rod (143) contacts the opposite sides of the two combined arc-shaped sheets (122) to drive the two to move.

6. A cleaning method using the wafer level flux cleaning apparatus according to any one of claims 1 to 5, characterized by: S1: adjust the angle of the nozzle (112) relative to the bearing table (100); S2: adjust the relative height of the nozzle (112) relative to the bearing table (100); S3: move the cleaning frame (110) so that the cleaning pipeline translates relative to the bearing table (100) for cleaning.

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