TWI838194B - Methods to improve the ball planting process - Google Patents

Abstract

The present invention discloses a method for improving the ball implantation process. First, a substrate is placed on a supporting platform, and a glue dispensing mold set is placed to cover the substrate. Then, a first sub-mold of the glue dispensing mold set is placed in a first sub-mold hole of a mold body of the glue dispensing mold set, and a plurality of first glue dispensing holes of the first sub-mold are aligned with a plurality of first ball implantation positions of the substrate. Then, a second sub-mold of the glue dispensing mold set is placed in a second sub-mold hole of a mold body of the glue dispensing mold set, and a plurality of second glue dispensing holes of the second sub-mold are aligned with a plurality of second ball implantation positions of the substrate, so that the first ball implantation position and the second ball implantation position of the substrate can be more completely exposed to the outside through the glue dispensing mold set.

Description

Methods to improve the ball placement process

The present invention is about a semiconductor ball implantation process method, which basically splits the original single-structure glue dispensing mold into a mold main body and multiple sub-molds. Since the processing object is a thin structure substrate that is easy to deform, the mold main body is used to fix the position of the substrate, and the sub-molds are used to adjust the local ball implantation positions.

In the semiconductor packaging process, it has become common to use conductive balls instead of needle-shaped pins in order to achieve the goal of miniaturization of electronic devices.

The ball placement process can be basically divided into five stages: flux printing, ball placement, reballing, reflow and cleaning. In the process of flux printing, because the packaging process is composed of a combination of different materials, the thermal expansion coefficients (CTE) of the materials added in the process are different, which will cause the substrate carrying different materials to expand and deform. This phenomenon will cause the position of the ball pad on the substrate to shift, which does not match the actual dispensing position of the dispensing mold. During the dispensing operation, the flux cannot be accurately applied to the substrate ball pad position, resulting in insufficient flux on the ball pad surface, which makes it easy to drop the ball later.

Regarding the literature on ball implantation process, there are several patents as follows:

Taiwan I649827 discloses a ball planting guide plate, which includes a plate, the top surface of which is formed with a plurality of guide grooves arranged at intervals, the bottom surface of each guide groove is formed with a plurality of ball holes arranged at intervals, and the plate forms a bearing part inside each ball hole, wherein the area between the guide groove and the ball hole is defined as a ball drop zone, wherein during the ball drop operation, the guide groove can guide the conductive balls to move into the guide groove and can be arranged one by one, and the conductive balls can move along the guide groove, and when they move to the ball drop zone, the conductive balls can smoothly fall into the ball holes and abut against the bearing part, thereby allowing each ball hole to have a conductive ball, thereby achieving the purpose of reducing the ball missing rate, thereby improving the convenience of the ball drop operation and shortening the ball drop operation time.

Taiwan M557910 discloses a ball implant fixture, including a ball implant steel plate, a substrate, and a support structure, wherein the support structure is disposed between the ball implant steel plate and the substrate, and is located in a non-operating area at the edge of the substrate.

Taiwan M334457 discloses a ball implantation machine mold structure, which is mainly composed of a mold body and a hole block, and a plurality of ball suction holes are formed on the hole block; thereby, when the ball suction holes on the hole block are damaged by being stuck or stuck with solder balls, the damaged hole block can be replaced separately without discarding the entire mold, thereby being more economical.

As mentioned above, as shown in FIG. 4a, the substrate (10) as a whole has a warping phenomenon, which makes it impossible for the dispensing unit (30) to accurately inject the flux. Although the above is aimed at reducing the warping phenomenon of the substrate as a whole to improve the flatness of the substrate periphery, as shown in FIG. 4b, the flux (31) on the substrate (10) is offset far from the center on both sides, but improving the yield of the ball implantation process is still an important topic that needs to be studied at present.

In view of the above problems, the present invention provides a method for improving the ball implantation process by splitting the original single-structure dispensing mold into a mold main body and multiple sub-molds, so that each ball implantation area can be fine-tuned separately.

Therefore, the main purpose of the present invention is to provide a method for improving the ball implantation process. In response to the problem of substrate warping and deformation, each area is aligned with the substrate ball pad position, so that the flux can be accurately applied to the substrate ball implantation pad position.

Another purpose of the present invention is to provide a method for improving the ball placement process, replacing the traditional method of using the entire dispensing mold to match the substrate to adjust the dispensing flux, saving adjustment time.

Another purpose of the present invention is to provide a method for improving the ball implantation process, which can improve the yield and reduce the production cost by improving the accuracy of the flux to the ball implantation pad position on the substrate.

To achieve the above purpose, the main technical means used in the present invention are realized by adopting the following technical solutions. The present invention is a method for improving the ball implantation process, which includes the following steps: Step 1: placing a substrate on a carrier platform and covering the substrate with a glue dispensing mold set; Step 2: placing a first sub-mold of the glue dispensing mold set in a first sub-mold hole of a mold body of the glue dispensing mold set, and aligning the first plurality of first glue dispensing holes of the first sub-mold with the first plurality of first ball implantation positions of the substrate; Step 3: placing a second sub-mold of the glue dispensing mold set in a second sub-mold hole of the mold body of the glue dispensing mold set, and aligning the second plurality of second glue dispensing holes of the second sub-mold with the second plurality of second ball implantation positions of the substrate.

The purpose of this invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

In the aforementioned method, after step 3, a third sub-mold of the glue dispensing mold set is placed in a third sub-mold hole of a mold body of the glue dispensing mold set, and a plurality of third glue dispensing holes of the third sub-mold are aligned with a plurality of third ball placement positions of the substrate.

In the aforementioned method, after step 3, multiple fluxes are injected into the first glue-dispensing holes and the second glue-dispensing holes through multiple glue-dispensing units.

The aforementioned method, wherein the first mold has a plurality of first adjustment positioning holes.

The aforementioned method, wherein the second mold has a plurality of second adjustment positioning holes.

The aforementioned method, wherein the third mold has a plurality of third adjustment and positioning holes.

The aforementioned method, wherein a plurality of glue dispensing units inject a plurality of fluxes into the third glue dispensing holes.

Compared with the prior art, the present invention has the following benefits: (1) By splitting the original single-structure dispensing mold into a mold main body and multiple sub-molds, each ball-planting area can be fine-tuned separately; (2) To solve the problem of substrate warping and deformation, each area is aligned with the substrate ball pad position, so that the flux can be accurately applied to the substrate ball pad position; (3) It replaces the traditional method of using the entire dispensing mold to adjust the substrate to apply the flux, saving adjustment time; (4) It improves the accuracy of the flux application to the substrate ball pad position, which can improve the yield and reduce production costs.

1: Step 1

2: Step 2

3:Step 3

3a:Step 3a

4:Step 4

4a:Step 4a

10: Substrate

101: First ball planting position

102: Second ball planting position

103: The third ball planting position

11: Carrying platform

20: Glue dispensing mold set

21: Mold body

211: The first die hole

212: Second die hole

213: The third die hole

22: The first mold

221: First glue hole

222: First adjustment positioning hole

23: The second mold

231: Second glue hole

232: Second adjustment positioning hole

24: The third mold

241: Third glue hole

242: The third adjustment positioning hole

30: Glue dispensing unit

31: Flux

[Figure 1a] is the first flow chart of the best implementation form of the present invention.

[Figure 1b] is the second flow chart of the best implementation form of the present invention.

[Figure 2a] is a schematic diagram of step 1 of the best embodiment of the present invention.

[Figure 2b] is the first schematic diagram of step 2 of the best embodiment of the present invention.

[Figure 2c] is the second schematic diagram of step 2 of the best embodiment of the present invention.

[Figure 2d] is the first schematic diagram of step 3 of the best embodiment of the present invention.

[Figure 2e] is the second schematic diagram of step 3 of the best embodiment of the present invention.

[Figure 2f] is the first schematic diagram of step 3a of the best embodiment of the present invention.

[Figure 2g] is a second schematic diagram of step 3a of the best embodiment of the present invention.

[Figure 3a] is the first schematic diagram of step 4 of the best embodiment of the present invention.

[Figure 3b] is the second schematic diagram of step 4 of the best embodiment of the present invention.

[Figure 3c] is the third schematic diagram of step 4 of the best embodiment of the present invention.

[Figure 3d] is the fourth schematic diagram of step 4 of the best embodiment of the present invention.

[Figure 3e] is the fifth schematic diagram of step 4 of the best embodiment of the present invention.

[Figure 3f] is the sixth schematic diagram of step 4 of the best embodiment of the present invention.

[Figure 4a] is the first schematic diagram of the existing problem of the present invention.

[Figure 4b] is a second schematic diagram of the existing problem of the present invention.

In order to make the purpose, features and effects of the present invention more clearly understood, the following specifically lists the preferred implementation forms of the present invention:

As shown in FIG1a, this is the best implementation form of a method for improving the ball implantation process of the present invention: please refer to the flow chart of FIG1a, which mainly consists of step 1 (1), step 2 (2) and step 3 (3).

As shown in Figures 1a and 2a, step 1 (1) is to place a substrate (10) on a supporting platform (11) and cover the substrate (10) with a glue dispensing mold set (20).

Specifically, the main purpose of step 1 (1) is to place the substrate (10) on the supporting platform (11) and position it, and use the glue dispensing mold set (20) to cover the substrate (10) to prepare for the subsequent installation of the first sub-mold (22) and the second sub-mold (23); wherein the substrate (10) refers to a carrier board with circuit and electrical conduction functions, which includes multiple positions for implanting solder balls and can also have a packaging structure; in addition, the supporting platform (11) serves as a supporting position for placing objects to be processed, and it can stably set the processed objects; the glue dispensing mold set (20) has the function of assisting in injecting materials such as flux or fixing glue into a fixed position, and includes multiple glue dispensing cavities thereon to facilitate alignment and injection in subsequent processing.

Referring to Figures 1a, 2b and 2c, step 2 (2) is to place a first sub-mold (22) of the glue dispensing mold set (20) in a first sub-mold hole (211) of a mold body (21) of the glue dispensing mold set (20), and to center and align the plurality of first glue dispensing holes (221) of the first sub-mold (22) with the plurality of first ball placement positions (101) of the substrate (10).

The important function of step 2 (2) is to place and position the first auxiliary mold (22) for assisting the first ball implantation position (101); the mold body (21) is the main body of the glue dispensing mold set (20), which has the function of setting the first auxiliary mold (22) and the second auxiliary mold (23); and the first auxiliary mold hole (211) is a concave structure for setting or fixing the first auxiliary mold (22) on the mold body (21); and the first auxiliary mold (22) is used for the To assist the first ball placement positions (101), the first glue holes (221) thereon are aligned as much as possible with the center of the first ball placement positions (101); and the first glue holes (221) are used to align as much as possible with the center of the first ball placement positions (101) to facilitate the subsequent processing of injecting flux; finally, the first ball placement position (101) refers to the position where the solder ball for injecting flux is placed, which will provide the substrate (10) with the effect of external electrical conduction.

Next, referring to FIG. 1a, FIG. 2d and FIG. 2e, step 3 (3) is to place a second sub-mold (23) of the glue dispensing mold set (20) in a second sub-mold hole (212) of the mold body (21) of the glue dispensing mold set (20), and to center and align the plurality of second glue dispensing holes (231) of the second sub-mold (23) with the plurality of second ball placement positions (102) of the substrate (10).

The important function of step 3 (3) is to place and position the second auxiliary mold (23) for assisting the second ball implantation position (102); the mold body (21) is the main body of the glue dispensing mold set (20), which has the function of setting the first auxiliary mold (22) and the second auxiliary mold (23); the second auxiliary mold hole (212) is a concave structure for setting or fixing the second auxiliary mold (23) on the mold body (21); in addition, the second auxiliary mold (23) is used for The second ball implantation positions (102) are assisted by aligning the second glue holes (231) thereon with the center of the second ball implantation position (102) as much as possible; and the function of the second glue holes (231) is to align the center of the second ball implantation positions (102) as much as possible, so as to facilitate the subsequent processing of injecting flux; finally, the second ball implantation position (102) refers to the position where the solder ball for injecting flux is placed, which will provide the substrate (10) with the effect of external electrical conduction.

In addition, after step 3 (3), step 4 (4) is performed as shown in FIG. 1a. Step 4 (4) is to inject a plurality of fluxes (31) into the first glue dispensing holes (221) (as shown in FIG. 3a and FIG. 3b) and the second glue dispensing holes (231) (as shown in FIG. 3c and FIG. 3d) through a plurality of glue dispensing units (30).

Specifically, step 4 (4) is divided into two parts, one of which is to inject a plurality of fluxes (31) into the first glue-dispensing holes (221) through a plurality of glue-dispensing units (30); the other is to inject a plurality of fluxes (31) into the second glue-dispensing holes (231) through a plurality of glue-dispensing units (30).

First, after step 2 (2) is completed, as shown in FIG2c, the first glue-dispensing holes (221) are used to align the centers of the first ball-planting positions (101) as much as possible; step 3 (3) is continued as shown in FIG3a, the glue-dispensing units (30) are located above the first sub-mold (22), waiting for the injection of flux (31); and step 3 (3) is continued as shown in FIG3b, the glue-dispensing units (30) are inserted into the first glue-dispensing holes (221), and the flux (31) is injected above the first ball-planting positions (101) of the substrate (10).

Secondly, after step 2 (2) is completed, as shown in FIG2e, the second glue-dispensing holes (231) are used to align the center of the second ball-planting positions (102) as much as possible; step 3 (3) is continued as shown in FIG3c, the glue-dispensing units (30) are located above the second sub-mold (23), waiting for the injection of flux (31); and step 3 (3) is continued as shown in FIG3d, the glue-dispensing units (30) are inserted into the second glue-dispensing holes (231), and the flux (31) is injected above the second ball-planting positions (102) of the substrate (10).

In practice, the dispensing units (30) are devices for injecting liquid substances, providing the function of uniformly injecting liquid substances; the flux (31) is a substance that uses chemical methods to clean the metal surface to be welded to facilitate soldering. Generally, the flux (31) contains ammonium chloride or rosin. In practice, the metal surface of the welding point is easy to form an oxide layer at high temperature, making it difficult for the welding material to adhere to the surface. Because the flux (31) is stable at room temperature and has strong reducing properties at high temperature, it can remove the oxide layer on the metal surface. At the same time, it has a protective effect and prevents oxidation reactions. In addition, the flux (31) can also act as a wetting agent during the soldering process to promote the soldering process.

Preferably, as shown in FIG2b, the first sub-mold (22) has a plurality of first adjustment and positioning holes (222), and as shown in FIG2d, the second sub-mold (23) has a plurality of second adjustment and positioning holes (232). The first adjustment and positioning holes (222) and the second adjustment and positioning holes (232) are used to fine-tune the first ball planting positions (101) and the second ball planting positions (102) so that their centers are aligned as much as possible, and can be fixed by means of positioning pins and the like.

In a more complicated situation, as shown in Figure 1b, step 3a(3a) is added after step 3(3), and step 4a(4a) is added after step 4(4).

Step 1(1), step 2(2), step 3(3), and step 4(4) in Figure 1b are the same as those in Figure 1a above and will not be described in detail.

Step 3a (3a) can refer to Figure 2f and Figure 2g. Step 3a (3a) is to place a third sub-mold (24) of the glue dispensing mold set (20) in a third sub-mold hole (213) of a mold body (21) of the glue dispensing mold set (20), and to center and align the plurality of third glue dispensing holes (241) of the third sub-mold (24) with the plurality of third ball placement positions (103) of the substrate (10).

The important function of step 3a (3a) is to place and position the third auxiliary mold (24) for assisting the third ball implantation position (103); the mold body (21) is the main body of the glue-pointing mold assembly (20), which has the function of setting the third auxiliary mold (24); and the third auxiliary mold hole (213) is a concave structure for setting or fixing the third auxiliary mold (24) on the mold body (21); in addition, the third auxiliary mold (24) is used for the third implantation positions (103) of the third auxiliary mold (24). The third point glue hole (241) on the third ball planting position (103) is aligned as much as possible with the center of the third ball planting position (103) to assist the placement of the third point glue hole (241). The third point glue hole (241) is used to align as much as possible with the center of the third ball planting position (103) to facilitate the subsequent processing of injecting flux. Finally, the third ball planting position (103) refers to the position where the solder ball for injecting flux is placed, which will provide the substrate (10) with the effect of external electrical conduction.

Step 4a (4a) is where a plurality of glue dispensing units (30) inject a plurality of fluxes (31) into the third glue dispensing holes (241).

The step 4a (4a) is as follows; after the step 3a (3a) is completed, as shown in FIG2g, the function of the third glue-dispensing holes (241) is to align the center of the third ball-planting positions (103) as much as possible; the step 3a (3a) is continued as shown in FIG3e, the glue-dispensing units (30) are located above the third sub-mold (24), waiting for the injection of flux (31); and the step 3 (3) is continued as shown in FIG3f, the glue-dispensing units (30) are inserted into the third glue-dispensing holes (241), and the flux (31) is injected above the third ball-planting positions (103) of the substrate (10).

The better one, as shown in FIG. 2f, has a plurality of third adjustment holes (242) in the third mold (24). The function of these third adjustment holes (242) is to fine-tune the centers of the third ball placement positions (103) to align them as much as possible, and fix them through mechanisms such as positioning pins.

Therefore, the effect of this invention is different from the general ball implant process improvement. It is the first of its kind in the ball implant process and meets the patent requirements. Therefore, an application is filed in accordance with the law.

However, it is necessary to reiterate that the above is only the preferred embodiment of the present invention. Any equivalent changes made by applying the present invention specification, patent application scope or drawings still fall within the technical scope protected by the present invention. Therefore, the protection scope of the present invention shall be subject to the definition of the attached patent application scope.

1: Step 1

2: Step 2

3:Step 3

4:Step 4

Claims (7)

A method for improving a ball implantation process comprises the following steps: Step 1: placing a substrate on a carrier platform and covering the substrate with a glue dispensing mold set; Step 2: placing a first sub-mold of the glue dispensing mold set in a first sub-mold hole of a mold body of the glue dispensing mold set, and centering and aligning a plurality of first glue dispensing holes of the first sub-mold with a plurality of first ball implantation positions of the substrate; Step 3: placing a second sub-mold of the glue dispensing mold set in a second sub-mold hole of a mold body of the glue dispensing mold set, and centering and aligning a plurality of second glue dispensing holes of the second sub-mold with a plurality of second ball implantation positions of the substrate. As in the method of claim 1, after step 3, a third sub-mold of the glue dispensing mold set is placed in a third sub-mold hole of a mold body of the glue dispensing mold set, and a plurality of third glue dispensing holes of the third sub-mold are aligned with a plurality of third ball placement positions of the substrate. As in the method of claim 1, after step 3, multiple fluxes are injected into the first glue dispensing holes and the second glue dispensing holes through multiple glue dispensing units. As in the method of claim 1, wherein the first mold has a plurality of first adjustment positioning holes. As in the method of claim 1, the second mold has a plurality of second adjustment positioning holes. As in the method of claim 2, the third mold has a plurality of third adjustment positioning holes. As in the method of claim 2, a plurality of glue dispensing units inject a plurality of fluxes into the third glue dispensing holes.

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