TW202123790A - Mask for solder ball array to solve the problem of falling off of a primary electrodeposition layer from a secondary electrodeposition layer, which leads to protrusion damage and the reduction in mounting rate of the conductive solder balls - Google Patents

Abstract

The subject of the present invention is to solve the problem that the primary electrodeposition layer falls off from the secondary electrodeposition layer on which the protrusions on the back of the mask are formed, which causes the protrusions to be damaged, and thereby leads to a decrease in the loading rate of conductive solder balls. The solder ball array mask 1 of the present invention has openings 30 corresponding to a specific array pattern. By loading conductive solder balls into the opening 30, the conductive solder balls are mounted at specific positions, and On the side of the solder ball array mask 1 opposite to the mounted body, there are provided protrusions 2 formed by laminating a secondary electrodeposition layer 4 on the primary electrodeposition layer 3, and a primary electrodeposition layer 3 of the protrusions 2 It has a structure that does not easily fall off from the secondary electrodeposition layer 4. In addition, the primary electrodeposition layer 3 of the protrusion 2 has a ring shape in a plan view, and a locking portion 11 is provided at the interface between the primary electrodeposition layer 3 and the secondary electrodeposition layer 4 of the protrusion 2.

Description

Mask for solder ball array

The invention relates to a mask for a solder ball array suitable for arranging conductive solder balls and a manufacturing method thereof.

Conventionally, in the metal mask for conductive solder ball array (hereinafter referred to as mask), in order to prevent the flux formed on the electrode of the conductive solder ball mounting portion from adhering to the mask, it is used on the substrate A recessed mask is formed on the periphery of the opening pattern on the face side. As a method of forming the recesses, the following method of manufacturing a mask is disclosed: A secondary electrodeposition layer is laminated on the primary electrodeposition layer by a plurality of electroforming methods to form the protrusions, and the primary electrodeposition layer is not provided On the other hand, the portion formed only by the secondary electrodeposition layer is referred to as a recessed portion (refer to Patent Document 1).

In addition, as a method of manufacturing a mask in which convex portions are formed by performing multiple plating methods, there is Patent Document 2 described below. The method of manufacturing a mask described in Patent Document 2 is a method of manufacturing a mask for a solder ball array, which is characterized in that the mask for a solder ball array includes a mask body and protrusions, and the mask is formed by plating. , And formed with a plurality of openings through which conductive solder balls are inserted. The protrusions are formed by plating and partially protrude beyond the openings on the back of the mask body. The front ends of the protrusions are formed The manufacturing method of the solder ball array mask includes the following steps: forming the above-mentioned protrusion-forming resist layer on the SUS base material; by making the above-mentioned protrusions a specific Highly plating is performed on the SUS base material to form the first plating layer; after the formation of the first plating layer is completed, the above-mentioned bump formation resist layer is removed; the first plating layer other than the above-mentioned bumps is removed, Leave the protrusions formed by the first plating layer on the SUS base material; form a plurality of opening-forming resist layers between the protrusions on the SUS base material; by making the mask body a designated In the method of thickness, the SUS base material and the protrusions are plated to form a second plating layer; after the formation of the second plating layer is completed, the plurality of opening-forming resist layers are removed; and from the above The protrusions composed of the first plating layer and the second plating layer and the plating layer of the mask body are peeled off from the SUS base material (refer to Patent Document 2). Furthermore, the electroforming method and the electroplating method are only different in expression, and the technical content is essentially the same. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2010-247500 [Patent Document 2] Japanese Patent Laid-Open No. 2017-5053

[The problem to be solved by the invention]

According to the manufacturing method described in Patent Document 1 or Patent Document 2, it is possible to form protrusions (hereinafter, also referred to as protrusions or protrusions) in any form on the back surface of the mask. The protrusion is formed by stacking a secondary electrodeposition layer on the primary electrodeposition layer, the primary electrodeposition layer is formed by a primary electroforming step, and the secondary electrodeposition layer is formed by a secondary electroforming step. Therefore, there is a time difference between the two steps. In the primary electroforming step and the secondary electroforming step, even if the electroforming conditions are set exactly the same, there will be a boundary between the primary electrodeposition layer and the secondary electrodeposition layer. .

If there is a boundary, the adhesion at the interface between the primary electrodeposition layer and the secondary electrodeposition layer will decrease. Even if chemical surface treatment such as hydrochloric acid treatment is performed on the primary electrodeposited layer after one electroforming step in order to improve the adhesiveness at the interface, there is a limit to the improvement of the adhesiveness. Moreover, if the cleaning operation is repeated in the stage of repeated use of the mask, the following problem will occur: in the mask with low adhesion, the primary electrodeposited layer is removed from the protrusions formed by the external force on the mask. The secondary electrodeposition layer comes off.

FIG. 10 shows a state where the primary electrodeposition layer 3 is peeled off from the secondary electrodeposition layer 4 on which the protrusions 2 are formed in the mask 1 manufactured by the prior art. Fig. 10(a) shows a normal state, and Fig. 10(b) shows a state where an external force F is applied from the protruding side (the back side of the mask). Since the thickness of the mask is as thin as several tens of μm, if an external force is applied from the protruding side, the mask is easily deformed. As a result, a gap is generated at the interface between the outer periphery of the primary electrodeposition layer and the secondary electrodeposition layer, and the primary electrodeposition layer falls off by being pushed out. Although whether or not the primary electrodeposition layer falls off actually depends on the size of the external force, if the mask is used repeatedly, it is confirmed that the primary electrodeposition layer with a considerable number of protrusions falls off.

If the primary electrodeposition layer falls off from the secondary electrodeposition layer on which the protrusions are formed, the strength of the protrusions as a whole may decrease, which may cause the protrusions to be damaged during use of the mask. As a result, there is a problem in that the flux formed on the electrode of the conductive solder ball mounting portion adheres to the mask, resulting in a decrease in the mounting rate of the solder balls.

In addition, if the primary electrodeposition layer falls off from the secondary electrodeposition layer on which the protrusions are formed, dents are formed on the surface side of the mask on which the conductive solder balls are loaded as falling traces. Therefore, the conductive solder balls may be hooked. The problem of the conductive solder balls hanging on the edge of the dent and unable to arrange the conductive solder balls reliably. [Technical means to solve the problem]

The present invention is a mask for a solder ball array, which is characterized by having openings corresponding to a specific array pattern, and by loading conductive solder balls into the openings, the conductive solder balls are mounted on the specific Position, and the mask for the solder ball array is provided with a plurality of primary electrodeposition layers and secondary electrodeposition layers: the plurality of primary electrodeposition layers separate a plurality of locations formed on the surface side of the mask for the solder ball array, The secondary electrodeposition layer is integrally formed on the part other than the primary electrodeposition layer and the primary electrodeposition layer; on the side of the solder ball array mask opposite to the mounted body, there is a combination of the primary electrodeposition layer and the The protrusion formed by the secondary electrodeposition layer has a locking part at the interface between the primary electrodeposition layer of the protrusion part and the secondary electrodeposition layer, and the primary electrodeposition layer of the protrusion part is not easy to fall off from the secondary electrodeposition layer . In addition, the mask for a solder ball array of the present invention is characterized in that the primary electrodeposition layer of the protruding portion is ring-shaped in a plan view, and the locking portion is the inner peripheral surface of the primary electrodeposition layer and the secondary electrodeposition layer. Between the interface. In addition, the mask for a solder ball array of the present invention is characterized in that the locking portion is mushroom-shaped or substantially spindle-shaped in a cross-sectional view. [Effects of Invention]

According to the mask of the present invention, the adhesion of the interface between the primary electrodeposition layer and the secondary electrodeposition layer on which protrusions are formed can be improved, and the primary electrodeposition layer can be prevented from falling off from the secondary electrodeposition layer. As a result, the bumps can be prevented from being damaged during use of the mask, and the flux formed on the electrodes of the conductive solder ball mounting portion does not adhere to the mask, thereby preventing the conductive solder ball mounting rate from decreasing. In addition, since dents are not generated on the surface side of the mask loaded with conductive solder balls, the conductive solder balls can be arranged smoothly and reliably.

Hereinafter, the method for implementing the present invention will be described with reference to the drawings. In the solder ball array mask, it is possible to form protrusions on the back surface of the mask by performing multiple electroforming steps. The protrusions of the prior art are formed by stacking a secondary electrodeposition layer on the primary electrodeposition layer, but the adhesion between the primary electrodeposition layer and the secondary electrodeposition layer is weak. If the mask is used repeatedly, it will cause the primary electrodeposition. The build-up layer is peeled off from the secondary electrodeposited layer.

Therefore, the inventors of the present invention have conducted careful studies to improve the adhesion of the interface between the primary electrodeposition layer and the secondary electrodeposition layer. In order to improve the adhesion, it may be considered to increase the area of the interface itself. However, the size of the top-view shape of the protrusion is bound to have its limitations, and there is a limit to increase the top-view area of the primary electrodeposited layer constituting the protrusion. [Example 1]

FIG. 1 is an enlarged cross-sectional view schematically showing the protrusion 2 of the mask 1 of Example 1. FIG. The protrusion 2 shown in the figure is formed by stacking a secondary electrodeposition layer 4 on the primary electrodeposition layer 3, and the primary electrodeposition layer 3 has a ring shape in a plan view. The shape of the ring is not limited to a circle, and may also be an ellipse, an oval, and a polygon, etc., but in this embodiment, it is a circular ring. In fact, because most of the masks have a size of hundreds of mm on one side, thousands of protrusions 2 as shown in the figure will be formed on one mask.

If the shape of the primary electrodeposition layer 3 in plan view is set to an annular shape in this way, the area of the interface 5 between the primary electrodeposition layer 3 and the secondary electrodeposition layer 4 in the plan view will be reduced by the equivalent of the primary electrodeposition layer 4 The part where the interface of the deposited layer 3 disappears. On the other hand, since the secondary electrodeposited layer 4 is also formed on the inner side of the ring of the primary electrodeposited layer 3, the inner side of the ring will form the equivalent of the primary electrodeposited layer 3. The thickness of the longitudinal annular interface 6 increases the area of the interface. For example, when the inner diameter of the ring is equal to the thickness of the primary electrodeposited layer 3, the relative decrease in the area of the interface increases by 0.75π(2.36) times. As a result, the area of the entire interface between the primary electrodeposition layer 3 and the secondary electrodeposition layer 4 including the interface 7 on the outer periphery of the ring-shaped primary electrodeposition layer 3 increases.

Although the increase of the interface area can effectively improve the adhesion of the interface between the primary electrodeposition layer 3 and the secondary electrodeposition layer 4, it is more important than increasing the area if the top view shape of the primary electrodeposition layer 3 is formed as In a ring shape, even if an external force F is applied from the protrusion 2 side, the ring-shaped primary electrodeposition layer 3 is locked on the secondary electrodeposition layer 4, so that a structure that is not easy to fall off can be realized.

In the mask 1 shown in FIG. 1, since the thickness of the mask 1 is as thin as several tens of μm, if an external force F is applied from the protrusion 2 side, the mask 1 is deformed, and the outer periphery of the primary electrodeposited layer 3 The interface 7 between the surface and the secondary electrodeposition layer 4 acts to generate a gap force. Moreover, in the interface 7 between the outer peripheral surface of the primary electrodeposition layer 3 and the secondary electrodeposition layer 4, a gap actually occurs. On the other hand, since there is an interface 6 between the inner peripheral surface of the ring-shaped primary electrodeposition layer 3 and the secondary electrodeposition layer 4, if an external force F acts from the side of the protrusion 2, the external force F will be at the interface 6. It acts as a pushing force in the direction of expanding the diameter of the interface. Therefore, even if the external force F is applied, the state where the primary electrodeposition layer 3 is locked at the interface 6 with the secondary electrodeposition layer 4 can be maintained, and the adhesion at the interface 6 is not damaged, thereby preventing the primary electrodeposition layer 3 from forming The secondary electrodeposition layer 4 with the protrusions 2 falls off. [Example 2]

FIG. 2 is an enlarged cross-sectional view schematically showing the protrusion 2 of the mask 1 of the second embodiment. In the cross-sectional view of the protrusion 2 in this embodiment, the primary electrodeposition layer 3 is formed in an inverted mushroom shape. That is, it has a shape in which the mushroom-shaped umbrella 8 and the handle 9 are inverted. Therefore, even if an external force acts from the side of the protrusion 2, it will not act on the interface of the primary electrodeposition layer 3 and the secondary electrodeposition layer 4 constituting the mushroom-shaped umbrella 8 such as to separate them from each other. Assuming that even if a large force is applied, only a tiny gap is formed at the interface 7 corresponding to the outer periphery of the mushroom-shaped shank 9 and the mushroom-shaped umbrella 8 is locked in the secondary electrodeposition layer 4. Therefore, even if an external force is applied from the protrusion 2 side, the state where the primary electrodeposition layer 3 is locked with the locking portion 11 of the secondary electrodeposition layer 4 can be maintained, thereby preventing the primary electrodeposition layer 3 from being removed from the secondary electrodeposition layer 4 4 Fall off. [Example 3]

3 is an enlarged cross-sectional view schematically showing the protrusion 2 of the mask 1 of the third embodiment. In the cross-sectional view of the protrusion 2 in this embodiment, the primary electrodeposition layer 3 is formed into a substantially spindle shape. Here, the term "substantially fusiform" refers to a shape in which the diameter of the middle part of the cylindrical shape is thick, and the diameters of the two ends gradually become smaller. When viewed in cross-section, the primary electrodeposited layer 3 is formed into a substantially spindle-shaped protrusion 2 and exerts the same function and effect as in the second embodiment. That is, even if an external force is applied from the protrusion 2 side, only a minute gap is generated at the interface 7 corresponding to the outer periphery of the primary electrodeposited layer 3, which is roughly spindle-shaped, and the largest diameter portion of the primary electrodeposited layer 3 is locked with the second The locking part 11 of the secondary electrodeposition layer. Therefore, even if an external force is applied from the protrusion 2 side, the state where the primary electrodeposition layer 3 is locked with the locking portion 11 of the secondary electrodeposition layer 4 can be maintained, thereby preventing the primary electrodeposition layer 3 from being removed from the secondary electrodeposition layer 4 4 Fall off. [Description of manufacturing method]

Based on the steps shown in FIG. 4, the manufacturing method of the solder ball array mask of the first embodiment of the present invention will be sequentially described.

As shown in FIG. 4(a), a master mold 20 is prepared, and a photoresist film 21 is formed on the surface of the master mold 20. The mother mold 20 may be anything as long as it has conductivity. In this embodiment, a SUS (Stainless Steel) material is used. Next, as shown in FIG. 4(b), on the photoresist film 21, a patterned resist film 22 is exposed to light by a well-known method.

As shown in FIG. 4( c ), the primary pattern resist film 22 on which the primary pattern is drawn is developed and dried, and the primary pattern resist film 22 is formed on the master mold 20. As shown in FIG. 5, the top view shape of the primary pattern resist film 22 formed in the steps so far is composed of a circular resist at the center and a ring-shaped resist formed concentrically therewith. Here, the primary pattern resist film 22 can be formed by laminating one or several negative photosensitive dry film resist films at a specific height.

The master mold 20 with the primary patterned resist film 22 is placed in an electroforming tank prepared under specific conditions, and as shown in FIG. 4(d), the electrodeposited metal is electroformed on the front of the master mold 20 The surface covered by the primary pattern resist film 22 is the same as the height of the primary pattern resist film 22, thereby forming the primary electrodeposition layer 3. The primary electrodeposited layer 3 can be formed by using Ni as the electrodeposited metal. Next, as shown in FIG. 4(e), the pattern resist film 22 is removed once.

As shown in FIG. 4(f), the waste electrodeposited layer 23 and the like that are not needed as a mask are removed. As shown in FIG. 6, the top view shape of the primary electrodeposition layer 3 formed in the steps so far is an annular shape.

As shown in FIG. 4(g), a photoresist film 25 is formed on the surface of the primary electrodeposition layer 3 and the master mold 20. The photoresist film 25 is formed by laminating one or several negative photosensitive dry film resist films according to a specific height. Next, as shown in FIG. 4(h), the secondary patterned resist film 26 is exposed on the photoresist film 25 by a well-known method.

As shown in FIG. 4(i), the secondary pattern resist film 26 on which the secondary pattern is drawn is developed and the unexposed portion is removed, so that the secondary pattern resist film 26 is formed on the master mold 20.

As shown in FIG. 4(j), electroforming is performed on the surface of the primary electrodeposition layer 3 formed on the master mold 20 and the surface of the master mold 20 not covered by the secondary pattern resist film 26 as the primary electrode The Ni of the same material as the deposition layer 3 forms a secondary electrodeposition layer 4. In the steps so far, the top view shape of the protrusion 2 formed by the secondary electrodeposition layer 4 is an annular shape as shown in FIG. 7. However, when the inner diameter of the annular primary electrodeposition layer 3 is small and the thickness of the secondary electrodeposition layer 4 is relatively thick, the electrodeposition layer is also formed at the center of the protrusion 2, which makes it difficult in appearance. It is recognized as a ring-shaped protrusion. Next, as shown in FIG. 4(k), the secondary pattern resist film 26 is removed, and openings 30 for arranging conductive solder balls are formed.

Then, as shown in FIG. 4(1), the integrated primary electrodeposition layer 3 and the secondary electrodeposition layer 4 are peeled off from the master mold 20 to obtain the solder ball array mask 1. According to the solder ball array mask 1 manufactured by the above method, even if an external force F is applied from the protrusion side, the state where the primary electrodeposition layer 3 is locked to the secondary electrodeposition layer 4 can be maintained, thereby preventing primary electrodeposition The build-up layer 3 is detached from the secondary electrodeposition layer 4.

Next, based on FIG. 8, the manufacturing method of the mask 1 for solder ball arrays of Example 2 of this invention is demonstrated. The manufacturing method of the solder ball array mask 1 of the second embodiment is basically the same as the manufacturing method of the solder ball array mask 1 of the first embodiment shown in FIG. 4. Therefore, in FIG. 8, only the steps that are different from those in FIG. 4 are described.

The steps shown in Fig. 8(a)(b)(c) correspond to the steps shown in Fig. 4(d)(e)(f) of Embodiment 1. 4 (d) (e) (f) is a schematic enlarged cross-sectional view, but since Example 2 needs to be further enlarged for description, therefore, FIG. 8 (a) (b) (c) is only a diagram showing 4(d)(e)(f) shows a schematic enlarged cross-sectional view of the right half.

In the step of forming the primary electrodeposition layer 3, as shown in FIG. 8(a), the master mold 20 with the primary patterned resist film 22 is placed in an electroforming tank prepared under specific conditions, and Electrodeposition is performed in a way that exceeds the thickness of the pattern resist film 22 once. In this way, a so-called overhang is formed on the primary electrodeposition layer 3 and used as the locking portion 11. The amount of overhang can be controlled by the time of the electroforming step. Next, as shown in FIG. 8(b), the pattern resist film 22 is removed once.

As shown in FIG. 8(c), the waste electrodeposited layer 23 and the like that are not needed as a mask are removed. The sectional view of the primary electrodeposition layer 3 formed in the steps so far is an inverted mushroom shape.

Next, based on the steps shown in FIG. 9, the manufacturing method of the solder ball array mask 1 of the third embodiment of the present invention will be described. The manufacturing method of the solder ball array mask 1 of the third embodiment is basically the same as the manufacturing method of the solder ball array mask 1 of the first embodiment shown in FIG. 4. Therefore, in FIG. 9, only the steps that are different from those in FIG. 4 are described.

The steps shown in Figure 9(a)(b)(c)(d)(e)(f) correspond to Figure 4(b)(c)(d)(e)(f)(j) in Example 1. ) Shows the steps. In addition, as shown in Fig. 8 of Example 2, Fig. 9(a)(b)(c)(d)(e)(f) is only shown in Fig. 4(b)(c)(d)(e ) A schematic enlarged cross-sectional view of the right half shown in (f)(j).

The manufacturing method of the mask 1 for the solder ball array of the third embodiment is characterized by the step of exposing the pattern resist film 22 once. Exposure can be carried out using a commercially available laser beam exposure device, but it is irradiated with the intensity of excess energy compared with the standard energy of the laser beam. In this way, because the SUS material is used in the master mold and the surface is mirror polished, the excess energy will be reflected on the surface of the master mold with halo. As a result, as shown in FIG. 9(a), the side of the primary pattern resist film 22 that is in contact with the master mold is cured into a skirt shape.

Next, as shown in FIG. 9(b), the primary pattern resist film 22 drawn with the primary pattern is developed and dried, and the primary pattern resist film 22 is formed on the master mold 20, as shown in FIG. 9(c) As shown in ), the master mold 20 with the primary patterned resist film 22 is placed in an electroforming tank formed by bathing under specific conditions, on the surface of the master mold 20 that is not covered by the primary patterned resist film 22 The metal is electroformed and electrodeposited to the same level as the height of the primary pattern resist film 22 to form the primary electrodeposition layer 3.

Furthermore, as shown in FIG. 9(d), the pattern resist film 22 is removed once, and as shown in FIG. 9(e), the waste electrodeposited layer 23 and the like that do not need to be used as a mask are removed. Then, after going through the same steps as in Fig. 4(g)(h)(i), as shown in Fig. 9(f), the primary electrodeposition layer 3 and the surface of the master mold 20 are electroformed and the primary electrodeposition layer 3 Ni of the same material forms a secondary electrodeposition layer 4. In this way, it is possible to form the primary electrodeposited layer 3 having a substantially spindle-shaped cross-sectional view. [Result of Falling-off Test]

3 mm之刺入型端子之測力計，進行了從遮罩之突起側施加30秒之100 N之外力之脫落試驗。關於遮罩試樣，遮罩之總厚度(一次電沈積層與二次電沈積層之合計厚度)分別設為45 μm、80 μm、120 μm，突起之高度分別設為25 μm、50 μm、60 μm，突起之俯視下之直徑為約200 μm。試驗結果為，所有突起均未發生脫落。For Example 1, the following three types of mask samples were made and used

The dynamometer with a 3 mm piercing terminal was tested by applying a force of 100 N from the projection side of the shield for 30 seconds. Regarding the mask sample, the total thickness of the mask (the total thickness of the primary electrodeposition layer and the secondary electrodeposition layer) was set to 45 μm, 80 μm, and 120 μm, respectively, and the protrusion height was set to 25 μm, 50 μm, and 60 μm, the diameter of the protrusion in plan view is about 200 μm. As a result of the test, none of the protrusions fell off.

3 mm之刺入型端子之測力計，進行了從遮罩之突起側施加30秒之100 N之外力之脫落試驗。關於遮罩試樣，遮罩之總厚度(一次電沈積層與二次電沈積層之總厚度)分別設為45 μm、80 μm、120 μm，突起之高度分別設為25 μm、50 μm、60 μm，並且突起之俯視下之直徑為約200 μm。試驗結果為，所有突起均未發生脫落。For Example 2 and Example 3, in the same way as Example 1, the following three types of mask samples were made and used

The dynamometer with a 3 mm piercing terminal was tested by applying a force of 100 N from the projection side of the shield for 30 seconds. Regarding the mask sample, the total thickness of the mask (the total thickness of the primary electrodeposition layer and the secondary electrodeposition layer) is set to 45 μm, 80 μm, and 120 μm, respectively, and the height of the protrusions is set to 25 μm, 50 μm, 60 μm, and the diameter of the protrusion in plan view is about 200 μm. As a result of the test, none of the protrusions fell off.

For comparison, the projections of the mask of the prior art were also subjected to the same fall-off test as in the above-mentioned embodiment. As a result, it was found that most of the three types of projections fell off. According to these test results, it can be confirmed that the adhesion of the interface between the primary electrodeposition layer and the secondary electrodeposition layer of the mask of the present invention is improved.

Above, the present invention has been described based on the embodiments, but the present invention is not limited to the above-mentioned embodiments. For example, in the above-mentioned Example 1, the top view shape of the primary electrodeposited layer forming the protrusions is set to a single circular ring, but the form of the ring is not limited to the form of a single ring, and may be a form of multiple rings. In addition, in the above-mentioned embodiment, the manufacturing method of the mask provided with the waste electrodeposition layer has been described, but of course it can also be applied to the manufacturing method of the mask without the waste electrodeposition layer. [Industrial availability]

The mask for the solder ball array of the present invention is suitable for arranging conductive solder balls on a substrate, etc., and the manufacturing method of the present invention can be used for manufacturing a secondary electrodeposition layer that prevents the primary electrodeposition layer from falling off the protrusion forming the mask Mask for the solder ball array.

1: Mask for solder ball array (mask) 2: Protruding part (protrusion) 3: Primary electrodeposition layer 4: Secondary electrodeposition layer 5, 6, 7: interface 8: Umbrella 9: handle 11: Locking part 20: master model 21: photoresist film 22: Primary pattern resist film 23: Waste electrodeposited layer 25: photoresist film 26: Secondary pattern resist film 30: Opening F: External force

FIG. 1 is an enlarged cross-sectional view schematically showing the protrusion of the mask of Example 1. FIG. FIG. 2 is an enlarged cross-sectional view schematically showing the protrusion of the mask of Example 2. FIG. FIG. 3 is an enlarged cross-sectional view schematically showing the protrusion of the mask of Example 3. FIG. 4(a) to (l) are explanatory diagrams showing the steps of the manufacturing method of the mask of the first embodiment. Fig. 5 is a plan view viewed from the direction of arrow A-A in Fig. 4(c). Fig. 6 is a plan view viewed from the direction of arrow B-B in Fig. 4(f). Fig. 7 is a top view of Fig. 4(j) viewed from the direction of arrow C-C. 8(a) to (c) are explanatory diagrams showing the steps of the manufacturing method of the mask of the second embodiment. 9(a) to (f) are explanatory diagrams showing the steps of the manufacturing method of the mask of the third embodiment. Fig. 10 (a) and (b) are enlarged cross-sectional views schematically showing the protrusions of the mask of the prior art.

1: Mask for solder ball array (mask)

2: Protruding part (protrusion)

3: Primary electrodeposition layer

4: Secondary electrodeposition layer

5: interface

6: Interface

7: Interface

F: External force

Claims (3)

A mask for a solder ball array, characterized in that it has an opening corresponding to a specific array pattern, and by loading conductive solder balls into the opening, the conductive solder balls are mounted at a specific position, and The solder ball array mask includes a plurality of primary electrodeposition layers and secondary electrodeposition layers, and the plurality of primary electrodeposition layers separate a plurality of locations formed on the surface side of the solder ball array mask. The electrodeposited layer is integrally formed on the part other than the above-mentioned primary electrodeposited layer and on the above-mentioned primary electrodeposited layer, On the side of the solder ball array mask opposite to the mounted body, there are protrusions formed by the primary electrodeposition layer and the secondary electrodeposition layer, There is a locking part at the interface between the primary electrodeposition layer and the secondary electrodeposition layer of the above-mentioned protruding part, The primary electrodeposition layer of the protruding part is not easy to fall off from the secondary electrodeposition layer. Such as the mask for the solder ball array of claim 1, where The primary electrodeposition layer of the protruding part is ring-shaped in a plan view, and the locking part is the interface between the inner peripheral surface of the first electrodeposition layer and the secondary electrodeposition layer. Such as the mask for the solder ball array of claim 1, where The above-mentioned locking portion is mushroom-shaped or substantially spindle-shaped in a cross-sectional view.

Images