JP2011181676A - Ball mounting mask, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball mounting mask and a method of manufacturing the same, wherein a step and a strain generated at an outer peripheral edge part of a boundary between an opening region where there is a dug recess and a no-opening region where there is not the dug recess are improved by forming many dimples (hollows) which substantially reach a depth of the dug recess in the no-opening region where there is not the dug recess. <P>SOLUTION: The ball mounting mask 3 has a screen gauze 2 stuck on a plate frame 1 by applying tension, composed of the opening region 5 where many ball insertion holes 4 into which conductive balls are inserted are formed, the no-opening region, and the dug recess formed by recessing a lower surface of the opening region, and has many dimples (hollows) 8 formed on a bottom surface side of the no-opening region of the ball mounting mask and suppressing the step and strain generated at the boundary between the opening region where there is the dug recess and the no-opening region where there is not the dug recess. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a ball mounting mask (also referred to as a ball transfer mask or a ball arrangement mask, but here referred to as a ball mounting mask) and a method of manufacturing the same.

  2. Description of the Related Art Conventionally, in a ball mounting mask in which conductive balls are distributed and arranged at predetermined positions on a semiconductor wafer, an electronic circuit board, and the like, the conductive balls formed corresponding to the arrangement pattern of electrodes on the wafer and the electronic circuit board are inserted. It is comprised by the opening part area | region in which many ball insertion holes were formed, the non-opening part area | region, and the digging recessed part for escaping the flux formed by denting the lower surface of an opening part area | region (for example, patent document 1) reference).

Japanese Patent Laying-Open No. 2008-186968 (FIG. 5)

  The conductive balls mounted on the ball mounting mask are becoming smaller year by year, and microball products in units of μm are becoming mainstream. In order to deal with such microball products, the ball mounting mask must have a thin plate thickness. For example, the plate thickness in the opening region is about 30 μm, the plate thickness in the non-opening region is about 60 μm, and flux is used. When the digging depth of the digging recess for escaping is 30 μm, when the ball mounting mask with a small plate thickness is attached to the plate frame via the screen ridge, for example, as shown in FIG. Steps and distortion occur at the outer peripheral edge of the boundary between the opening region 5 having 7 and the non-opening region 6 having no digging recess. And this is considered to cause a step or distortion due to the difference in the plate thickness of the boundary, and there was a problem that the microball remained on the ball mounting surface side on the mask when mounting the ball . Even if it is not a microball, the same problem may occur if the depth of the dug recess is increased and the plate thickness of the opening region is reduced.

  The present invention has been made to solve the above-described problems, and has a large number of dimples (dents) reaching the vicinity of the depth of the recessed portion in the non-opening region where there is no recessed portion for escaping the flux. A ball mounting mask and a method of manufacturing the same, which can improve the step and distortion generated at the outer peripheral edge of the boundary between the opening region with the digging recess and the non-opening region without the digging recess by forming It is to provide.

  In the ball mounting mask according to the present invention, an opening region in which a large number of ball insertion holes are formed, which are attached to the plate frame with tension through a screen ridge and through which conductive balls are inserted, and a non-opening region region. , A ball mounting mask composed of a digging recess formed by denting the lower surface of the opening region, and formed on the bottom side of the non-opening region of the ball mounting mask and having an digging recess And a large number of dimples (dents) that suppress steps and distortions that occur at the boundary between the non-opening region having no digging recess.

  In addition, an opening region having a plate thickness of about 15 to 30 μm in which a large number of ball insertion holes through which conductive balls are inserted is formed by applying tension to the plate frame via a screen rod, and a plate thickness of 30 to 30 mm. A ball mounting mask composed of a non-opening region of about 60 μm and a digging recess having a depth of about 15 to 30 μm formed by recessing the lower surface of the opening region, the non-opening region of the ball mounting mask A large number that suppresses the level difference and distortion generated at the boundary between the opening area with the digging depression and the non-opening area without the digging depression. The dimple (dimple) is provided.

  In addition, a large number of dimples (dents) are circular, rectangular, or honeycomb.

  Of the many dimples (dents), the circular, rectangular, or honeycomb-shaped dimples (dents) located on the innermost side partially cover the digging depressions in the opening region and communicate with the digging depressions. And is open.

  In addition, a large number of dimples (dents) are formed such that the size of the dimples (dents) decreases as the distance from the side closer to the digging recess in the opening region increases.

  Further, in the ball mounting mask manufacturing method according to the present invention, an opening region formed with a number of ball insertion holes through which conductive balls are inserted and applied to the plate frame with tension through a screen ridge, A ball mounting mask composed of a non-opening region and a digging recess formed by denting the lower surface of the opening region, the digging recess formed on the bottom side of the non-opening region of the ball mounting mask In a method of manufacturing a ball-mounted mask having a large number of dimples (dents) that suppress steps and distortions that occur at the boundary between an opening region with a non-opening region without a digging recess, A step of forming a first resist and forming a plurality of ball insertion hole resists in the opening region, and an opening region and a non-opening portion in which a plurality of ball insertion holes are formed by performing first-stage plating region Forming a first-stage plating layer comprising: a second resist is formed thereon; a digging recess resist is formed in the opening region; and the digging recess depth is formed in the non-opening region. A step of forming a dimple (dimple) resist to be reached, and plating in the second stage to form a digging recess in the opening region and to reach the depth of the digging recess in the non-opening region The method includes a step of forming a second-stage plating layer on which is formed, a resist removal step of removing the resist, and a peeling step of peeling the mask layer from the conductive base material.

  In addition, the plate frame is affixed with tension through a screen rod, and an opening region in which a large number of ball insertion holes through which conductive balls are inserted, a non-opening region, and a lower surface of the opening region are recessed. A ball mounting mask composed of a digging recess formed on the bottom surface of the non-opening region of the ball mounting mask and having a digging recess and a non-opening without a digging recess. In a method for manufacturing a ball mounting mask having a large number of dimples (dents) that suppress steps and distortions that occur at the boundary with a partial region, a first resist is formed on a conductive base material, and a large number of openings are formed in the opening region. Forming a resist for the ball insertion hole and first-stage plating to form a first-stage plating layer comprising an opening area and a non-opening area in which a large number of ball insertion holes are formed And the process The second resist is formed, and the resist for the recessed portion is formed in the opening region, and the dimple (recessed portion) is reduced in size toward the non-opening region from the side closer to the recessed portion of the opening region. ) A resist forming step and second-stage plating are performed, and a recessed portion is formed in the opening region, and the non-opening region is moved away from the side closer to the recessed portion of the opening region. From the step of forming the second plating layer formed so as to reduce the size of the dimple (dent), the resist removal step of removing the resist, and the peeling step of peeling the mask layer from the conductive base material It will be.

  According to the present invention, a step or distortion that is formed on the bottom surface side of the non-opening region of the ball mounting mask and that occurs at the boundary between the opening region with the digging recess and the non-opening region without the digging recess is suppressed. Since there are a large number of dimples (dents), the conventional problem that the ball remains on the ball mounting surface side on the mask when the ball is mounted can be solved.

It is the perspective view seen from the plane side which shows the state which attached the ball mounting mask in Example 1 of this invention to the plate frame through the screen collar. It is the perspective view seen from the bottom face side which shows the state which attached the ball mounting mask in Example 1 of this invention to the plate frame through the screen collar. It is a top view which expands and shows the principal part of the ball mounting mask in Example 1 of this invention. It is sectional drawing along the AA line of FIG. The main part expansion which shows that there is no level | step difference and distortion at the boundary of the opening part area | region with a digging recessed part of a ball mounting mask in Example 1 of this invention, and the non-opening part without a digging recessed part, and a ball mounting surface side is flat. It is sectional drawing. It is a top view which expands and shows the principal part of the ball mounting mask in Example 2 of this invention. It is a top view which expands and shows the principal part of the ball mounting mask in Example 3 of this invention. It is a top view which expands and shows the principal part of the ball mounting mask in Example 4 of this invention. It is a top view which expands and shows the principal part of the ball mounting mask in Example 5 of this invention. It is a top view which expands and shows the principal part of the ball mounting mask in Example 6 of this invention. It is sectional drawing along the BB line of FIG. It is a longitudinal cross-sectional view which shows the method of manufacturing the ball mounting mask in the Example of this invention by two steps plating in order of a process. An enlarged cross-sectional view of a main part showing a state where a step or distortion occurs at the boundary between an opening region with a digging recess of a conventional ball mounting mask and a non-opening without a digging recess and the ball mounting surface side is not flat. It is.

  1 is a perspective view seen from the plane side showing a state in which the ball mounting mask according to the first embodiment of the present invention is attached to the plate frame via a screen cage, FIG. 2 is a perspective view seen from the bottom side, and FIG. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3, and FIG. 5 is an opening region having a digging concave portion and a digging concave portion of the ball mounting mask. It is a principal part expanded sectional view which shows that there is no level | step difference and distortion at the boundary with the non-opening part which is not, and a ball mounting surface side is flat.

  1 and 2, reference numeral 1 denotes a plate frame made of aluminum material or the like in a rectangular frame shape, 2 denotes a screen cage made of a mesh stretched inside the plate frame 1, and 3 denotes a central portion of the screen cage 2 This is a ball-mounted mask that is bonded and fixed to. The ball mounting mask 3 is a flat plate manufactured by a manufacturing method using two-step plating described later, and the peripheral edge thereof is bonded to the screen rod 2 with an adhesive. The ball mounting mask 3 is formed corresponding to an electrode arrangement pattern of a semiconductor wafer, an electronic circuit board or the like, and has an opening region 5 in which a large number of ball insertion holes 4 through which conductive microballs in units of μm are inserted, A non-opening region 6 and a digging recess 7 for escaping the flux formed by denting the lower surface of the opening region 5 are configured. The ball mounting mask 3 is used for a semiconductor wafer, an electronic circuit board, and the like, and a plurality of electrodes are provided on the semiconductor wafer, the electronic circuit board, etc., and each ball insertion hole 4 of the ball mounting mask 3 is a semiconductor. It corresponds to each electrode such as a wafer and an electronic circuit board.

  The ball mounting mask 3 has a structure as shown in FIGS. That is, the opening region 5 in which many ball insertion holes 4 through which conductive microballs in units of μm are inserted has a plate thickness of about 15 to 30 μm, and the non-opening region 6 has a plate thickness of about 30. The depth of the digging recess 7 for escaping the flux formed by recessing the lower surface of the opening region 5 is about 15 to 30 μm. In the ball mounting mask 3 of the present invention, a large number of circular dimples 8 are formed on the bottom surface side of the non-opening region 6 so as to reach the vicinity of the depth of the digging recess 7. As shown in FIG. 2, this circular dimple 8 is preferably formed only inside the non-opening region 6 of the mask, and is preferably not formed on the outer periphery. Further, it is preferable that the innermost dimple (recess) 8 is as close as possible to the dug recess 7. The circular dimples (dents) 8 are regularly arranged at equal intervals in the vertical and horizontal directions, and have a diameter of 400 μm and a rib width of 400 μm, for example. In this way, a large number of circular dimples (dents) 8 reaching the vicinity of the depth of the digging recess 7 are formed on the bottom surface side of the non-opening region 6, so that the opening region 5 having the digging recess 7 is formed. It was found that the step and distortion generated due to the difference in the thickness of the boundary between the non-opening region 6 and the non-opening region 6 having no digging recesses can be suppressed and improved. Thereby, it is possible to improve the problem that microballs in units of μm remain on the ball mounting surface side on the mask when the ball is mounted.

  FIG. 6 is an enlarged plan view showing a main part of the ball mounting mask according to the second embodiment of the present invention.

  In the first embodiment, a large number of circular dimples 8 that reach the vicinity of the depth of the digging recess 7 are formed on the bottom surface side of the non-opening region 6. As shown in FIG. 6, a large number of rectangular dimples 8a are formed. The rectangular dimples (dents) 8a are regularly arranged at equal intervals in the vertical and horizontal directions, and are, for example, 400 μm × 400 μm and a rib width of 400 μm. As described above, a large number of rectangular dimples (dents) 8a reaching the vicinity of the depth of the digging recess 7 are formed on the bottom surface side of the non-opening region 6, so that the opening region 5 having the digging recess 7 is formed. It was found that the step and distortion generated due to the difference in the thickness of the boundary between the non-opening region 6 and the non-opening region 6 having no digging recesses can be suppressed and improved. Thereby, it is possible to improve the problem that microballs in units of μm remain on the ball mounting surface side on the mask when the ball is mounted. Note that the shape may be a triangle instead of a rectangle.

  FIG. 7 is an enlarged plan view showing a main part of the ball mounting mask according to the third embodiment of the present invention.

  In the first embodiment, a large number of circular dimples (dents) 8 are formed on the bottom surface side of the non-opening region 6 so as to reach the vicinity of the depth of the digging recess 7, and the circular dimples located on the innermost side are formed. The (dimple) 8 is arranged so as to be a little away from the digging recess 7 in the opening region 5, but in this third embodiment, as shown in FIG. 7, a circular dimple (dimple) is provided. The shape of the circular dimple (dent) 8b located on the innermost side of FIG. 8 is changed to, for example, a 3/4 circular shape. That is, the innermost circular dimple (recess) 8 b is opened in such a manner that a part of the circular shape covers (overlaps) the dug recess 7 in the opening region 5 and communicates with the dug recess 7 side. It is a so-called 3/4 circular shape. Thereby, the digging recessed part 7 surface side becomes not a linear shape but a special waveform shape. In this way, since the digging recess 7 in the opening region 5 covers a part of the circle and is open to communicate with the digging recess 7 side, the opening region 5 having the digging recess 7 and the digging recess are provided. It has been found that steps and distortions caused by the difference in plate thickness at the boundary with the non-opening region 6 having no gap can be further suppressed and effectively improved. Thereby, it is possible to further improve the problem that microballs in units of μm remain on the ball mounting surface side on the mask when the ball is mounted.

  FIG. 8 is an enlarged plan view showing the main part of the ball mounting mask according to the fourth embodiment of the present invention.

  In the first embodiment, a large number of circular dimples (recesses) 8 that reach the vicinity of the depth of the digging recess 7 are formed on the bottom surface side of the non-opening region 6, and the circular dimples (recesses) 8 are formed. Are regularly arranged at equal intervals in the vertical and horizontal directions. In Example 4, as shown in FIG. 8, a large number of circular dimples 8c are formed, and the circular dimples 8c are alternately formed. Are arranged in a zigzag pattern.

  FIG. 9 is an enlarged plan view showing a main part of the ball mounting mask according to the fifth embodiment of the present invention.

  In the first embodiment, a large number of circular dimples 8 that reach the vicinity of the depth of the digging recess 7 are formed on the bottom surface side of the non-opening region 6. 9, a large number of honeycomb-shaped dimples (dents) 8d are formed. The honeycomb-shaped dimples (dents) 8d are regularly arranged at equal intervals in the vertical and horizontal directions. As described above, since a large number of honeycomb-shaped dimples (dimples) 8d reaching substantially the vicinity of the depth of the digging recess 7 are formed on the bottom surface side of the non-opening region 6, the opening region 5 having the digging recess 7 is formed. It was found that the step and distortion generated due to the difference in the thickness of the boundary between the non-opening region 6 and the non-opening region 6 having no digging recesses can be suppressed and improved. Thereby, it is possible to improve the problem that microballs in units of μm remain on the ball mounting surface side on the mask when the ball is mounted. Further, the innermost honeycomb-shaped dimple (dimple) 8d is a deformation in which a part of the honeycomb shape is covered (overlapped) with the dug recess 7 in the opening region 5 and communicated with the dug recess 7 side to be opened. You may make a pentagon shape. Furthermore, it is not limited to the honeycomb shape, but may be other polygonal shapes.

  FIG. 10 is an enlarged plan view showing the main part of the ball mounting mask according to the sixth embodiment of the present invention, and FIG. 11 is a sectional view taken along the line BB of FIG.

  In the first embodiment, a large number of circular dimples (recesses) 8 reaching almost the depth of the digging recesses 7 are formed on the bottom surface side of the non-opening region 6, and the circular dimples (recesses) 8 are formed. Although both the size and the depth are the same shape, in Example 6, as shown in FIGS. 10 and 11, as the distance from the side closer to the recessed portion 7 of the opening region 5 increases, the depth and the depth gradually increase. The circular dimple (recess) 8e is formed to have a small size. The circular dimples (dents) 8e are regularly arranged at equal intervals in the vertical and horizontal directions. In this way, on the bottom side of the non-opening region 6, the size of the circular dimple (recess) 8 e is gradually reduced as it goes away from the side closer to the recessed portion 7 of the opening region 5. As a result, it is possible to suppress and improve the step and distortion generated due to the difference in the thickness of the boundary between the opening region 5 having the digging recess 7 and the non-opening region 6 having no digging recess. I understood. Thereby, it is possible to improve the problem that microballs in units of μm remain on the ball mounting surface side on the mask when the ball is mounted.

Next, a manufacturing method of the ball mounting mask in the embodiment of the present invention will be described with reference to FIG. This manufacturing method is a lamination process by two-step plating, and the ball mounting mask in Example 1 will be described as a representative example.
First, the first resist 11 is applied on the conductive base material 10 (see FIG. 12a), and a number of ball insertion hole resists 11a are formed in the opening region by exposure and development (see FIG. 12b). Then, when the first-stage plating is performed, a first-stage plating layer 12 including an opening area and a non-opening area in which a large number of ball insertion holes are formed is formed (see FIG. 12c). Next, a second resist 13 is applied from above (see FIG. 12d), and a digging recess resist 13a for escaping the flux to the opening region is formed by exposure and development, and digging into the non-opening region. A circular dimple (dent) resist 13b is formed that reaches substantially the vicinity of the depth of the recess (see FIG. 12e). Then, when the second stage plating is performed, a recessed portion for escaping the flux is formed in the opening region, and a circular dimple (recessed in the non-opening region) reaches the vicinity of the depth of the recessed portion. ) Is formed (see FIG. 12f). Thereafter, the resists 11a, 13a and 13b are removed (FIG. 12g) and peeled off from the conductive base material 10 to obtain the ball mounting mask 3 of the present invention (see FIG. 12h).

As a manufacturing method of the ball mounting mask according to the embodiment of the present invention, the ball mounting mask according to the first embodiment has been described as a representative example. However, when a large number of rectangular dimples (recesses) 8a according to the second embodiment are formed, a rectangular shape is used. A dimple (dimple) having a rectangular shape reaching the vicinity of the depth of the concave portion may be formed by digging into the non-opening region.
When a large number of honeycomb-shaped dimples (dimples) 8d of Example 5 are formed, a honeycomb-shaped dimple (dimple) resist is formed and dug into the non-opening region to reach substantially the depth of the concave portion. A honeycomb-shaped dimple (dent) may be formed. Further, in the case where the size of the circular dimple 8e is gradually reduced as it goes away from the side closer to the digging recess 7 in the opening region 5 of Example 6, the digging dent is formed. A dimple (dimple) resist is formed to gradually reduce the size of the circular dimple (dimple) 8e as it goes away from the side closer to 7 and away from the side closer to the digging recess 7 in the opening region 5. What is necessary is just to form so that the magnitude | size of the circular dimple (recess) 8e may become small gradually as it goes to the side.

DESCRIPTION OF SYMBOLS 1 Plate frame 2 Screen 紗 3 Ball mounting mask 4 Ball insertion hole 5 Opening area 6 Non-opening area 7 Excavation recessed part 8 Circular dimple (dimple)
8a Rectangular dimple
8d Honeycomb dimple
DESCRIPTION OF SYMBOLS 10 Conductive base material 11 1st resist 11a Ball insertion hole resist 12 1st step plating layer 13 2nd resist 13a Engraving recess resist 13b Circular dimple (dimple) resist 14 2nd step Plating layer

Claims (7)

An opening area, a non-opening area, and a lower surface of the opening area are recessed, which are affixed to the plate frame through a screen rod with tension applied to form a large number of ball insertion holes through which conductive balls can be inserted. A ball mounting mask composed of a digging recess formed by
Numerous dimples that are formed on the bottom side of the non-opening region of the ball mounting mask and suppress steps and distortions that occur at the boundary between the opening region having the digging recess and the non-opening region having no digging recess. A ball-mounted mask characterized by comprising a (dent). An opening region having a plate thickness of about 15 to 30 μm and a plate thickness of about 30 to 60 μm, in which a large number of ball insertion holes through which conductive balls are inserted are formed by applying tension to the plate frame via a screen cage. A non-opening region and a ball mounting mask composed of a recessed portion with a depth of about 15 to 30 μm formed by recessing the lower surface of the opening region,
The bottom surface of the non-opening region of the ball mounting mask is formed to reach the vicinity of the depth of the digging recess, and an opening region with the digging recess and a non-opening region without the digging recess A ball-mounted mask comprising a large number of dimples (dents) that suppress steps and distortions that occur at the boundary.   3. The ball mounting mask according to claim 1, wherein the plurality of dimples (dents) are circular, rectangular, or honeycomb.   Among the numerous dimples (dents), the circular, rectangular, or honeycomb-shaped dimples (dents) located on the innermost side partially cover the digging recess in the opening region and communicate with the digging recess side. 4. The ball mounting mask according to claim 3, wherein the ball mounting mask is open.   5. A large number of dimples (dents) are formed so that the size of the dimples (dents) decreases as the distance from the side closer to the recessed portion of the opening region decreases. A ball-mounted mask according to any of the above. An opening area, a non-opening area, and a lower surface of the opening area are recessed, which are affixed to the plate frame through a screen rod with tension applied to form a large number of ball insertion holes through which conductive balls can be inserted. A ball mounting mask composed of a digging recess formed on the bottom surface side of the non-opening region of the ball mounting mask, and having an opening region with the digging recess and no digging recess. In the manufacturing method of the ball mounting mask provided with a large number of dimples (dents) that suppress the step and distortion generated at the boundary with the opening region,
A first resist is formed on the conductive base material, and a plurality of ball insertion hole resists are formed in the opening region, and the first stage plating is performed to form a plurality of ball insertion holes. Forming a first-stage plating layer comprising an opening region and a non-opening region, forming a second resist thereon, forming a digging recess resist in the opening region, A step of forming a dimple (dimple) resist that reaches the depth of the recessed portion in the opening region and a second-stage plating are performed so that the recessed portion is formed in the opening region and the non-opening region is formed. A step of forming a second-stage plating layer in which dimples (recesses) reaching the depth of the recessed portion are formed, a resist removal step of removing the resist, and a peeling step of peeling the mask layer from the conductive base material And consisting of Method of manufacturing a ball mounting mask according to claim. An opening area, a non-opening area, and a lower surface of the opening area are recessed, which are affixed to the plate frame through a screen rod with tension applied to form a large number of ball insertion holes through which conductive balls can be inserted. A ball mounting mask composed of a digging recess formed on the bottom surface side of the non-opening region of the ball mounting mask, and having an opening region with the digging recess and no digging recess. In the manufacturing method of the ball mounting mask provided with a large number of dimples (dents) that suppress the step and distortion generated at the boundary with the opening region,
A first resist is formed on the conductive base material, and a plurality of ball insertion hole resists are formed in the opening region, and the first stage plating is performed to form a plurality of ball insertion holes. A step of forming a first-stage plating layer comprising an opening region and a non-opening region, a second resist is formed thereon, a digging recess resist is formed in the opening region, A step of forming a dimple (dimple) resist having a smaller size as it moves away from the side closer to the recessed portion of the opening region in the non-opening region, and performing the second-stage plating, And a dimple (dent) is formed in the non-opening region so that the size of the dimple (indentation) decreases as the distance from the side of the opening region close to the dug recess is increased. Work to form plating layer When a resist removal step of removing the resist, the production method of the ball mounting masks, characterized in that comprising a stripping step of peeling the mask layer from the conductive base material.

Images