JP2023003830A - Copper pillar production method - Google Patents

Abstract

To provide a copper pillar production method capable of easily shaping the shape of a copper pillar top face into a flat or almost flat one.SOLUTION: A substrate having a hole structure surrounded by a resist pattern formed on a conductive layer, in which a bottom face of the hole structure is provided with a recessed part and the bottom face including the recessed part is covered with the conductive layer is dipped into a tank of a copper plating liquid, electrolytic copper plating is performed while stirring the copper plating liquid at a set liquid flow rate, and the recessed part-including hole structure is filled with a plating metal to acquire a copper pillar. At this time, a plating time is bisected into a first half and a second half, and the electrolytic copper plating is performed so that a value obtained by dividing the liquid flow rate in the first half by the liquid flow rate in the second half reaches 0.8 or less or 1.2 or more. Plating treatment in a state where a promotion effect with respect to copper precipitation is high and plating treatment in a state where a suppression effect with respect thereto is high are performed to perform plating treatment so that a top face of the copper pillar is made almost flat.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for manufacturing a copper pillar (copper post).

In recent years, with the progress of miniaturization of semiconductor wiring, in package substrates such as FC-BGA (Flip Chip-Ball Grid Array) that adjusts the wiring width of the semiconductor and the mother board, solder is being used on the connection surface between the semiconductor and the package substrate. Copper pillars are being used to prevent short-circuiting (bridging) of bumps.
When solder bumps are formed on copper pillars, it is desirable that the connection surface is as flat as possible. In order to make the shape of the connection surface between the solder bump and the copper pillar nearly flat, it is effective to make the top surface of the copper pillar nearly flat.

One method of forming copper pillars is electrolytic copper plating. In this method, a resist layer is formed on a substrate provided with a conductive layer for electrical conduction, the resist is removed from the portions where the copper pillars are to be formed to form a resist pattern that will become recesses, and electrolytic copper plating is performed to form a resist pattern. A columnar structure is formed by depositing copper in the blanks or recesses of the resist pattern.
When copper pillars are formed by electrolytic copper plating, the plating bath contains additives called accelerators and inhibitors in addition to the main components copper sulfate, sulfuric acid, and hydrochloric acid. Accelerators and inhibitors are components that promote or suppress the growth of plating due to slight differences in concentration in the plating solution. , is added.

In molding by electrolytic copper plating, it is easy to obtain a desired shape to some extent where the shape is defined by the resist pattern, such as the side wall of a copper pillar. Conversely, in a portion with a high degree of freedom in shape, such as the top surface of a copper pillar, it is almost impossible to obtain a completely uniform plating deposition and a flat top surface.
The shape of the top surface of the copper pillar obtained by the actual electrolytic copper plating process is usually convex or concave.
As a solution to the phenomenon that the top surface becomes convex or concave in this way, for example, in Patent Document 1, after electrolytic plating is performed in a plating bath with a large acceleration effect, the accelerator is removed, and plating with a small acceleration effect is performed. A method of electroplating in a bath to flatten the via geometry is disclosed.

Japanese Patent No. 3594894

However, in the method described in Patent Document 1, in addition to two plating baths with different acceleration effects, a bath for removing the accelerator in the first plating bath is also required, and the space for providing the bath and the bath It is thought that there is a problem with production efficiency in terms of indirect time when transferring.
In view of the above circumstances, it is an object of the present invention to provide a copper pillar manufacturing method capable of obtaining a copper pillar with a flat top surface without lowering production efficiency.

According to one aspect of the present invention, the hole structure is surrounded by a resist pattern formed on the conductive layer, the bottom surface of the hole structure has a recess, and the bottom surface including the recess is covered with the conductive layer. The substrate is immersed in a bath of copper plating solution, electrolytic copper plating is performed while stirring the copper plating solution in the bath at a set solution flow rate, and the hole structure including the recesses is filled with plating metal to obtain copper pillars. In the copper pillar manufacturing method, the plating time for the substrate is divided into the first half and the second half, and the value obtained by dividing the liquid flow rate in the first half by the liquid flow rate in the second half is 0.8 or less or 1.2 or more. A method for manufacturing a copper pillar is provided by electrolytic copper plating. It should be noted that the halving is not limited to the case of dividing into two parts having exactly the same length of time, but may have a slight difference in the length of time between the first half and the second half.

According to the present invention, the shape of the top surface of the copper pillar can be easily adjusted to be flat or almost flat without adding a plating bath or changing the composition of the plating solution, and the shape of the top surface of the copper pillar can be easily adjusted to a semiconductor chip or the like. You can get a reliable connection.

FIG. 4 is a schematic diagram showing changes in the shape of a copper pillar depending on the strength of the plating solution flow; FIG. 4 is a schematic diagram showing changes in the shape of a copper pillar depending on the strength of the plating solution flow; FIG. 3 is a schematic diagram showing an example of a cross section of the copper pillar of FIG. 2; FIG. 4 is a schematic diagram showing the behavior of an additive depending on the strength of the flow of a plating solution; FIG. 4 is a schematic diagram showing the plating growth process when there is a resin opening under the copper pillar;

Embodiments of the present invention will be described below with reference to the drawings. In order to omit redundant description, constituent elements having the same or similar functions are denoted by the same reference numerals in the drawings. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimension, the ratio of thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. In addition, it is a matter of course that there are portions with different dimensional relationships and ratios between the drawings.

Further, the embodiments shown below are examples of devices and methods for embodying the technical idea of the present invention. etc. are not specified below. Various modifications can be made to the technical idea of the present invention within the technical scope defined by the claims.

In a method for manufacturing a copper pillar according to an embodiment of the present invention, a hole structure surrounded by a resist pattern formed on a conductive layer is provided. The substrate covered with the conductive layer is immersed in a bath of copper plating solution, electrolytic copper plating is performed while stirring the copper plating solution in the bath at a set solution flow rate, and the hole structure including the recesses is formed into the plating metal. A copper pillar manufacturing method for obtaining copper pillars by filling with by dividing the plating time for the substrate into the first half and the second half, and the value obtained by dividing the liquid flow rate in the first half by the liquid flow rate in the second half is 0.8 Electrolytic copper plating is performed so that the value becomes less than or equal to or greater than 1.2.
That is, for example, when a hole structure formed in a resist layer for forming a copper pillar is filled with copper by electrolytic plating, the plating bath It creates a liquid flow inside.

Depending on the size and direction of the liquid flow, various differences in liquid flow may occur between the inside of the pore structure and the surrounding area of the pore structure entrance. The plating growth rate is higher inside the hole structure than around the structure, and the inside of the hole structure is filled with copper. Also, when the difference in liquid flow between the inside of the pore structure and the periphery of the pore structure is too small, the accelerator does not accumulate in the pore structure, and there is almost no difference in the plating growth rate between the inside of the pore structure and the periphery of the pore structure. , the possibility of insufficient filling inside the pore structure increases. For the same reason, the top surface of the plating in the hole structure tends to be concave. Conversely, if the difference in liquid flow between the inside of the pore structure and the periphery of the pore structure is too large, the liquid exchange rate inside the pore structure is high, and the accelerator inside the pore structure is scraped out. There is almost no difference in the plating growth rate between the inside of the hole structure and the vicinity of the hole structure entrance. Therefore, by using the effect of these liquid flows, it is possible to form a copper pillar with a flat or almost flat top surface.

Specifically, in a series of electrolytic copper plating processes, the accelerator acts sufficiently to form a slightly protruding top surface of the plated metal inside the hole structure, and the accelerator does not work sufficiently. and a stage in which the action of the inhibitor becomes dominant and the growth of the plated metal in the pore structure is somewhat slowed down. Then, at each stage, the liquid flow rate of the plating bath is manipulated to vary the action of the accelerator.

FIG. 1 shows an example of a copper pillar 1 formed by electroplating, and shows an outline of the cross-sectional shape of the cylindrical portion of the copper pillar 1. FIG. In FIG. 1, the cross-sectional shape 2 indicated by the solid line is obtained by setting the liquid flow of the plating solution constant under the condition that the accelerator stays inside the hole structure for forming the copper pillar 1 and the accelerator works sufficiently. It is a schematic diagram of the cross-sectional shape including the top surface of the copper pillar 1 when formed, and the top surface shape of the copper pillar 1 swells greatly in a convex shape. In FIG. 1, a cross-sectional shape 3 indicated by a dashed line is a schematic diagram of a cross-sectional shape showing an example of a copper pillar 1 formed by an electrolytic plating method to which the copper pillar manufacturing method according to the present invention is applied. It is the schematic of the cross-sectional shape at the time of changing the liquid flow of a liquid. As shown in FIG. 1, the copper pillar 1 formed by the electroplating method to which the method for manufacturing a copper pillar according to the present invention is applied has a suppressed swelling of the top surface of the copper pillar 1. As shown in FIG.

FIG. 2 shows an example of the copper pillar 19 formed by the electroplating method, and shows an outline of the cross-sectional shape of the cylindrical portion of the copper pillar 19. As shown in FIG. In FIG. 2, the cross-sectional shape 20 indicated by the dashed line is such that the flow of the plating solution is such that the promoter does not sufficiently penetrate into the hole structure for forming the copper pillar 19, or is immediately discharged even if it penetrates. FIG. 3 is a schematic diagram of a cross-sectional shape of a copper pillar 19 formed under constant conditions, and the top surface shape of the copper pillar 19 is greatly recessed. In FIG. 2, a cross-sectional shape 21 indicated by a solid line is a schematic diagram of a cross-sectional shape showing an example of a copper pillar 19 formed by an electrolytic plating method to which the copper pillar manufacturing method according to the present invention is applied. It is the schematic of the cross-sectional shape at the time of changing the liquid flow of a liquid. As shown in FIG. 2, it can be seen that the copper pillar 19 formed by the electroplating method to which the copper pillar manufacturing method according to the present invention is applied suppresses the depression of the top surface shape of the copper pillar 19 .

FIG. 3 is an example of the overall cross-sectional shape of the copper pillars 1 and 19 shown in FIGS. 1 and 2. FIG. The copper pillars 1 and 19, as shown in FIG. 3, have a via portion 7 corresponding to a so-called via directly below the cylindrical portion 8. As shown in FIG.
In FIG. 3, 5 is an insulating resin layer such as a solder resist, 6 is a power supply part called a seed layer, 5a is an opening of the insulating resin layer 5, and the opening 5a of the insulating resin layer 5 is filled with electrolytic plating. The via portion 7 is formed by filling with the copper deposited by . A copper pillar 4 is formed by the via portion 7 and the cylindrical portion 8 formed directly above the via portion 7 .

The structure shown in FIG. 3 is a structure called an SMD pad (Solder Mask Defined), and has a via portion 7 as a blind via below the cylindrical portion 8 of the copper pillar 4 . In the case of the SMD pad structure, it is necessary to fill the via portion 7 formed in the insulating resin layer 5 and form the cylindrical portion 8 of the copper pillar 4 to flatten the top surface of the copper pillar 4 . As described above, if the promoting effect in forming the cylindrical portion 8 is too weak, the top surface shape of the copper pillar 4 is recessed, and if the promoting effect is too strong, the top surface shape of the copper pillar 4 swells into a convex shape, resulting in the promoting effect. is appropriate, the top surface of the copper pillar 4 is substantially flat.

FIG. 4 is a schematic diagram showing the behavior of the additive depending on the strength of the flow of the plating solution. In FIG. 4, 9 is a plating bath, 10 is an insulating resin layer, 11 is a photosensitive resist, 12 is a power supply part called a seed layer, 13 is a copper pillar made of deposited copper, and 14 is 15 indicates the liquid flow (flow) of the plating solution; 16 is an accelerator contained in the plating solution; 17 is a suppressor contained in the plating solution; An opening (hereinafter also referred to as a photosensitive resist opening) is shown.

As a feature of the accelerator 16 in the electrolytic copper plating bath, when a difference in flow rate 15 of the plating solution occurs between the inside of the photosensitive resist opening 18 and the surface of the photosensitive resist 11, the flow rate 15 of the plating solution is small. That is, the accelerator 16 accumulates in the photosensitive resist opening 18 . However, if the difference in flow 15 of the plating solution between the inside of the photosensitive resist opening 18 and the surface of the photosensitive resist 11 is insufficient, the accumulation of the accelerator 16 in the photosensitive resist opening 18 does not progress. Further, when the difference in the flow 15 of the plating solution between the photosensitive resist opening 18 and the surface of the photosensitive resist 11 is excessive, the plating solution 14 in the photosensitive resist opening 18 is quickly replaced, and the photosensitive resist opening 14 is changed rapidly. Accumulation of accelerator 16 in portion 18 does not progress.

That is, as shown in FIG. 4(a), when the difference in the flow 15 of the plating solution between the inside of the photosensitive resist opening 18 and the surface of the photosensitive resist 11 is not sufficient, the flow of the plating solution is accelerated into the photosensitive resist opening 18. The accumulation of the agent 16 does not proceed, and the inhibitory effect becomes stronger, and the smoothing agent, which is one of the components contained in the inhibitor 17, makes the top surface of the copper pillar 13 a slightly concave plated shape.
On the other hand, as shown in FIG. 4(b), when the difference in flow 15 of the plating solution between the inside of the photosensitive resist opening 18 and the surface of the photosensitive resist 11 is sufficient, the flow inside the photosensitive resist opening 18 is accelerated. As the accumulation of the agent 16 progresses, the acceleration effect becomes stronger, and the top surface of the copper pillar 13 becomes a convex plated shape.

4(c), when the difference in flow 15 of the plating solution between the inside of the photosensitive resist opening 18 and the surface of the photosensitive resist 11 is excessive, the plating solution inside the photosensitive resist opening 18 14 is replaced quickly, the accumulation of the accelerator 16 in the photosensitive resist opening 18 does not progress, the inhibitory effect becomes stronger, and the smoothing agent, which is one of the components contained in the inhibitor 17, smoothes the top of the copper pillar 13. The surface shape becomes a slightly concave plating shape.

Next, regarding the peripheral structure of a copper pillar arranged on a wiring board, the difference in throwing power of electrolytic plating depending on the magnitude of the effect of the accelerator will be described.
FIG. 5 shows an example of the structure in the growth process of electrolytic plating when forming the copper pillar 4 having the via portion 7 directly below the cylindrical portion 8 of the copper pillar as shown in FIG. In FIG. 5, 5 is an insulating resin layer, 5a is an opening formed in the insulating resin layer, 6 is a power supply portion, 11 is a photosensitive resist, and 23 is deposited copper.

FIG. 5(a) shows the growth process of electrolytic plating in a state where the acceleration effect is strong. When the acceleration effect is strong, as shown in FIG. 4B, the accelerator 16 accumulates in the openings 5a of the insulating resin layer 5 and is deposited by electrolytic plating in the openings 5a of the insulating resin layer 5. The copper 23 thus formed has a convex shape.
FIG. 5(b) shows the growth process of electrolytic plating in a state where the suppressing effect is strong. As shown in FIG. 4(a) or FIG. 4(c), when the accelerator 16 is not biased, the copper 23 deposited by electrolytic plating has a shape following the shape of the power supply portion 6 or is contained in the suppressor 17. The smoothing agent, which is one of the ingredients used in the coating, makes the shape almost flat or slightly concave. If the copper 23 deposited by electrolytic plating grows in a shape that follows the shape of the power supply portion 6, the copper 23 deposited by electrolytic plating becomes recessed. In order to prevent such depressions from occurring, an accelerating effect by an accelerator is required.

FIG. 5(c) shows another example of the growth process of electrolytic plating in a state where the suppressing effect is strong. As shown in FIG. 4(a) or FIG. 4(c), when the accelerator 16 is not biased, the copper 23 deposited by electrolytic plating has a shape following the shape of the power supply portion 6 or is contained in the suppressor 17. Although the smoothing agent, which is one of the components of the insulating resin layer 5, forms a substantially flat shape, due to uneven growth of the copper 23 deposited by electrolytic plating, the opening 5a of the insulating resin layer 5 can be formed by electrolytic plating while leaving the gap 24. It may be filled with deposited copper 23 . In order not to generate such a gap 24, the acceleration effect of the accelerator 16 is necessary.

In this way, when electrolytic plating is performed on a wiring substrate including a hole structure (corresponding to the opening 5a in FIG. 5), the effect of the accelerator 16 is polarized as to whether the effect is too large or insufficient. By using both of them together, it is possible to adjust to a good shape. Specifically, when plating is first performed under conditions in which the action of the accelerator 16 is too large, plating is performed later under conditions in which the effect of the accelerator 16 is suppressed, so that the shape of the top surface is finally changed. A substantially flat plating shape can be obtained, and conversely, when plating is first performed under conditions in which the effect of the accelerator 16 is suppressed, by plating later under conditions in which the effect of the accelerator 16 is large, Finally, a substantially flat plated shape can be obtained.

Through extensive research, the inventors found out how to change the liquid flow rate in the electrolytic copper plating process to cancel out the excessive and insufficient effects of the accelerator, and to obtain a good plating shape as a whole. I found something.
That is, in a series of electrolytic copper plating processes, the accelerator acts sufficiently, and the top surface of the plated metal inside the hole structure becomes a slightly protruding shape, and the accelerator does not work sufficiently. and at each stage the flow rate of the plating bath is manipulated to vary the action of the accelerator in order to slightly slow down the growth of the plating metal within the pore structure as the action of the inhibitor becomes dominant. .

That is, in the electrolytic copper plating bath 9 shown in FIG. The accelerator 16 accumulates in the openings 18 of the resist, increasing the acceleration effect and depositing the plated film from the bottom up. The bottom-up deposited plating film swells, but in order to flatten the swell, if the flow rate of the liquid flow 15 of the plating solution on the surface of the photosensitive resist 11 is adjusted by adjusting the flow rate of the plating solution, for example, by doubling, the thickness of the photosensitive resist increases. The liquid exchange rate between the plating solution 14 in the opening 18 and the bulk is increased, the accumulation of the accelerator in the opening 18 of the photosensitive resist is suppressed, and the inhibitory effect is increased, and the plated film surface becomes substantially flat.

Therefore, as shown in FIG. 5, a hole structure is provided which is surrounded by a photosensitive resist (resist pattern) 11 formed on the seed layer (conductive layer) 6 and becomes the cylindrical portion 8 of the copper pillar 4 shown in FIG. , a substrate having an opening (recess) 5a to be the via portion 7 in FIG. It is immersed in a bath of a copper plating solution, electrolytic copper plating is performed while stirring the copper plating solution in the bath at a set solution flow rate, and the hole structure including the opening (recess) 5a is filled with the plating metal. , The plating time for the substrate is divided into the first half and the second half, and electrolytic copper plating is performed so that the value obtained by dividing the liquid flow rate in the first half by the liquid flow rate in the second half is 0.8 or less or 1.2 or more. As a result, the top surface of the copper pillar can be made substantially flat while suppressing the formation of gaps in the via. The plating time referred to here means the time from the start of filling the opening (recess) 5 a until the height of the deposited copper reaches the height required for the cylindrical portion 8 .

In this way, by switching the liquid flow rate during the electrolytic copper plating process, the top surface of the copper pillar 4 can be made substantially flat, and the formation of a gap in the via portion 7 can be suppressed, so that the copper pillar 4 A good plating shape can be obtained as a whole. Therefore, a highly reliable connection with a semiconductor chip or the like can be obtained.

(Example 1)
A plating solution was prepared with copper sulfate, sulfuric acid, hydrochloric acid, an inhibitor, and an accelerator in a jet-type electrolytic plating apparatus with a volume of 300 L. A 300 mm×300 mm substrate to be plated was plated at a current density of 2 A/dm ² for 20 minutes in the electrolytic plating apparatus. As shown in FIG. 3, a photosensitive resist is formed on the substrate to be plated so that a copper pillar 4 having a columnar portion 8 arranged on a via portion 7 is formed. The jet flow rate per minute was 10 L/min, and the jet flow rate in the last 10 minutes was 20 L/min. was made. At this time, the value obtained by dividing the jet flow rate (liquid flow rate) in the first half of the electrolytic copper plating process by the jet flow rate (liquid flow rate) in the latter half was 0.5.

(Example 2)
In the plating apparatus in which the bath was prepared, the photosensitive resist was formed as shown in FIG. The plated substrate was plated at a current density of 2 A/dm ² for 20 minutes. The jet flow rate for the first 10 minutes of the electrolytic copper plating process was 16 L/min, and the jet flow rate for the last 10 min was set to 20 L/min. I was able to make it almost flat. At this time, the value obtained by dividing the jet flow rate (liquid flow rate) in the first half of the electrolytic copper plating process by the jet flow rate (liquid flow rate) in the latter half was 0.8.

(Example 3)
In the plating apparatus in which the bath was prepared, the photosensitive resist was formed as shown in FIG. The plated substrate was plated at a current density of 2 A/ ^dm2 for 20 minutes. The jet flow rate for the first 10 minutes of the electrolytic copper plating process was 24 L/min, and the jet flow rate for the last 10 min was set to 20 L/min. I was able to make it almost flat. At this time, the value obtained by dividing the jet flow rate (liquid flow rate) in the first half of the electrolytic copper plating process by the jet flow rate (liquid flow rate) in the latter half was 1.2.

(Example 4)
In the plating apparatus in which the bath was prepared, the photosensitive resist was formed as shown in FIG. The plated substrate was plated at a current density of 2 A/ ^dm2 for 20 minutes. The jet flow rate for the first 10 minutes of the electrolytic copper plating process was 30 L/min, and the jet flow rate for the last 10 minutes was 20 L/min. I was able to make it almost flat. At this time, the value obtained by dividing the jet flow rate (liquid flow rate) in the first half of the electrolytic copper plating process by the jet flow rate (liquid flow rate) in the latter half was 1.5.

(Comparative example 1)
In the plating apparatus in which the bath was prepared, the photosensitive resist was formed as shown in FIG. The plated substrate was plated at a current density of 2 A/dm ² for 20 minutes. When the jet flow rate for the first 10 minutes of the electrolytic copper plating process was 18 L/min and the jet flow rate for the last 10 min was 20 L/min, the cross-sectional shape of the copper pillar protruded like the cross-sectional shape 2 indicated by the solid line in FIG. became a thing At this time, the value obtained by dividing the jet flow rate (liquid flow rate) in the first half of the electrolytic copper plating process by the jet flow rate (liquid flow rate) in the latter half was 0.9.

(Comparative example 2)
In the plating apparatus in which the bath was prepared, the photosensitive resist was formed as shown in FIG. The plated substrate was plated at a current density of 2 A/dm ² for 20 minutes. When the jet flow rate for the first 10 minutes of the electrolytic copper plating process was 22 L/min and the jet flow rate for the last 10 min was set to 20 L/min, the cross-sectional shape of the copper pillar protruded like cross-sectional shape 2 indicated by the solid line in FIG. became a thing At this time, the value obtained by dividing the jet flow rate (liquid flow rate) in the first half of the electrolytic copper plating process by the jet flow rate (liquid flow rate) in the latter half was 1.1.

(Confirmation of actions and effects)
From the examples and comparative examples, the liquid flow rate of the plating bath is changed by a certain ratio or more depending on the first and second halves of the electrolytic copper plating process, and the effect of the accelerator is insufficient and the effect of the accelerator is excessive. By combining these conditions, it was confirmed that a favorable shape was obtained in the electrolytic copper plating process as a whole.

1, 19 Schematic diagram of cross-sectional shape of copper pillar 2, 20 Schematic diagram of cross-sectional shape of copper pillar formed with constant flow of plating solution 3, 21 Copper formed by changing flow of plating solution midway Schematic diagrams of cross-sectional shapes of pillars 4 and 13 Copper pillars 5 and 10 Insulating resin layer 5a Openings 6 and 12 in the insulating resin layer Power feeding portion 7 Via portion 8 of copper pillar 8 Cylindrical portion of copper pillar 9 Plating bath 11 Photosensitive resist 14 Plating solution 15 Plating solution flow (flow)
16 Accelerator 17 Suppressor 18 Opening of photosensitive resist 22 Growth process of electrolytic plating 23 Copper deposited by electrolytic plating 24 Gap

Claims (1)

A substrate having a hole structure surrounded by a resist pattern formed on a conductive layer, having a recess in the bottom surface of the hole structure, and having the bottom surface including the recess covered with a conductive layer is coated with a copper plating solution. is immersed in a tank, electrolytic copper plating is performed while stirring the copper plating solution in the tank at a set liquid flow rate, and the hole structure including the recess is filled with plating metal to obtain a copper pillar. A method for manufacturing a pillar,
The plating time for the substrate is divided into a first half and a second half, and the electrolytic copper is adjusted so that the value obtained by dividing the liquid flow rate in the first half by the liquid flow rate in the second half is 0.8 or less or 1.2 or more. A method of manufacturing a copper pillar, comprising plating.

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