KR102101052B1 - 3d tsv assembly method for mass reflow - Google Patents

Abstract

Disclosed herein is a method comprising picking up a plate comprising at least one opening with a nozzle to allow air to flow through. The method includes picking up the die with a nozzle such that the plate is positioned between the nozzle and the die. The method includes placing the die and plate on a device, substrate or other die such that the plate is positioned on top of the die. The method includes heating the die and the device, substrate, or other die in a heating chamber while the plate remains on top of the die to permanently attach the die to the device, substrate, or other die. Further disclosed herein is an assembly system configured to perform a method of using a plate and die combination to attach a die to a device, substrate, or other die by heating.

Description

3D TSV ASSEMBLY METHOD FOR MASS REFLOW for mass production reflow

Cross reference to related applications

This application claims the benefit of US Provisional Application No. 61 / 659,092 filed August 30, 2012 (invention name: 3D TSV ASSEMBLY METHOD FOR MASS REFLOW).

Technology field

The present disclosure generally relates to electronic assembly. More specifically, the present disclosure is part of a 3D assembly for mass production reflow or reflow soldering (also called 3D through-silicon via ("TSV")) as a part of a die or other on a substrate. It relates to a method of assembling a die on a die.

The dies on the die or dies in the 3D TSV assembly can be thin enough to tend to die during the heating or mass production reflow or bonding process. This is called the "potato chip" effect in industry. The "potato chip" effect leaves many bad connections between the base die and the upper die. The current solution to this problem is to use a special nozzle that will enable in-situ bonding of the die during deployment. The problem with this solution is that the die often needs to be heat treated before the nozzle can be removed. To speed it up, the nozzle must be heated and also able to cool quickly. So, the entire process of placing the die by the nozzle takes a considerable amount of time for each die, because the nozzle must remain at the placement site to heat and cool the die before moving to pick up another portion. Even if progress has been made, the above heating and cooling process results in a very low batch rate. Moreover, the equipment required to perform these processes is expensive due to the required batch accuracy. So, equipment cost and time cost (with a tact time of 5 to 60 seconds per die) make this an expensive process step in TSV assembly. Additionally, the use of local heating and cooling at the tip of the nozzle makes it more difficult to reach the required accuracy in the placement and attachment steps.

Thus, a die or 3D TSV assembly method and assembly machine on a die compatible with mass production reflow methods that alleviate or prevent many of the problems described herein above will be well accepted in the art.

According to one embodiment, the method comprises: picking up a plate comprising at least one opening to allow the air to flow through the nozzle; Picking up the die with the nozzle such that the plate is positioned between the nozzle and the die; Placing the die and plate on a device, substrate or other die such that the plate is positioned on top of the die; And heating the device and die in a heating chamber while the plate remains on top of the die to permanently attach the die to the device, substrate, or other die.

According to another embodiment, a method includes: a) picking up a combination of a plate and die with a nozzle such that the plate is positioned between the die and the nozzle; b) placing the combination of plate and die on a device, substrate or other die; c) repeating steps a) and b) to mount multiple combinations of plates and dies on a device, substrate or other die; d) simultaneously heating the device, substrate or other die and multiple combinations of plates and die to attach each of the die to the device, substrate or other die; And e) removing each of the plates from each of the dies.

According to another embodiment, the assembly system includes: an assembly machine; And a heating chamber, wherein the assembly machine is a nozzle configured to pick up a combination of plate and die such that the plate is positioned between the nozzle and the die, the plate including at least one opening to allow air to flow through, The nozzle wherein the plate is picked up at the first pick-up point and the die picked up at the second pick-up point; And a placement location for placing the combination of plate and die on the device, substrate, or other die by the nozzle, wherein the nozzle is configured to mount multiple combinations of plates and die on the device, substrate, or other die. Further comprising, the heating chamber is configured to heat the entire device, substrate, or other die to attach the die to the device, substrate, or other die.

Some embodiments of the present invention will be described in detail with reference to the following drawings in which similar names indicate similar members:
1A is a top view of a plate;
1B is a cross-sectional view of the plate shown in FIG. 1A;
2A is a top view of a die with TSV;
2B is a side view of the die with TSV shown in FIG. 2A;
3A is a side view of the nozzle;
Fig. 3B is a cut away view of the nozzle shown in Fig. 3A taken from arrows 3B-3B;
4A to 4C are depictions of the picking process of a plate by a nozzle;
5A to 5C are diagrams of a pick process of 3D TSV by plate and nozzle;
6A-6C are diagrams of a process for placing a 3D TSV and plate on a device by a nozzle;
7A-7C are diagrams of a process for removing a plate from a 3D TSV mounted on a device through a cleaning process;
8A-8C depict depictions of another process for removing a plate from a 3D TSV mounted on a device by a nozzle;
9A-9C are depictions of another process for removing a plate from a 3D TSV mounted on a device through another cleaning process; And
10 is a plan view of an assembly system capable of performing the processes shown in FIGS.

DETAILED DESCRIPTION OF THE EMBODIMENTS The detailed description of the embodiments described below of the disclosed apparatus and method is presented here as an example with reference to the drawings and is not limiting.

1 to 6 and 10, a nozzle 16 that can be part of a pick and place head 110 mounted on the assembly machine 100 of the assembly system 1000 is shown. It is done. 4A-4C, the nozzle can first pick up the plate 10, which is approximately the size of the 3D TSV or die 14 to be placed and attached, from the feeder 112. This plate 10 can be very flat and maintains the flatness of the die 14 during the mass production reflow process to prevent the "potato chip" effect when the plate 10 is leaning on top of the die 14 It may have a sufficient weight to. For example, the plate 10 can weigh as much or more than the die 14. The plate 10 may have a thickness greater than that of the die 14. Plate 10 may be semi-permeable. Permeability can be created by small orifice type holes 12 in the plate 10. Alternatively, the plate 10 can be made of sintered material that allows air to pass from some bottom but not all to the top. This can create a pressure difference between the bottom and top of the plate 10, allowing the plate 10 to be picked up by suction from the nozzle 16. The plate 10 can be constructed of a material that is very unsolderable to prevent the plate from adhering to the die during the reflow process. In other words, the plate 10 can be made of a material that will not deform when exposed to high temperatures in the reflow process. The plate 10 can also be polished with such a surface finish that allows molecular attraction (Vanderwald's force) to cause the die 14 to stick to the plate 10 during the mass production reflow / bonding process.

The assembly sequence may be as follows. First, the nozzle 16 is lowered on the top of the clean flat plate 10, as shown in FIGS. 4A and 4B. The vacuum or suction at the nozzle 16 is sufficiently built up by a limited air flow through the plate 10 caused by the structure of the sintered material of the plate or the size of the orifice, so that the plate is a nozzle as shown in Fig. 4c. (16). The next optional step is to optimize the alignment of the plate 10 relative to the nozzle 16 prior to picking up the die 14 so that the die 14 is centered on the die 14 upon pickup of the die 14. It will be the vision centering of the plate 10 by the vision system 114.

After the nozzle 16 picks up the plate, the nozzle 16 and plate 10 are then lowered on top of the die 14 from another feeder 112, as shown in FIGS. 5A and 5B. . The die 14 may include solder bumps 15 for mass production reflow processes. Since the die 14 may not be breathable, such as the plate 10, bringing the plate 10 into contact with the die, as shown in FIG. 5B, can cause the orifice opening to be closed causing a full vacuum to build up. This can enable the die 14 to be picked up under the plate 10 by a nozzle 16, as shown in FIG. 5C. Following this, die 14 will go through the current process steps for flip chip placement, which may include dipping the solder bumps 15 onto the adhesive or flux, vision centering steps and placement steps on the board. You can.

As shown in FIG. 6A, after picking up a combination of die 14 and plate 10, nozzle 16 may move to a placement location on a substrate, base die, board, or other device 18. When the vacuum is removed from the nozzle 16, the die 14 to which the plate 10 is added can remain on the substrate, or base die, board or other device 18, as shown in FIG. 6B. . At this point, the nozzle 16 can be removed immediately to pick up another plate and die combination 10, 14 for placement on the device 18. Thus, it is understood that the nozzle 16 need not include any heating or cooling mechanism. Moreover, no other device in the assembly machine needs to heat or cool it individually to attach die 14 to device 18.

Instead of individual heating of individual dies 14 to device 18, device 18 may be fully mounted with multiple plate and die combinations 10, 14 prior to heating. From here, the mounting device 18 can be transferred to the heating chamber 200 (shown in FIG. 10) by the assembly machine 100. The heating chamber 200 may be, for example, an oven chamber or other heating chamber. The mounting device 18 can move along the heating chamber 200 in an assembly line type manner. Alternatively, the mounting device 18 can move to the center of the heating chamber 200 and remain there until the mass production reflow process is complete. Whatever the embodiment, the heating chamber 200 can melt the solder bumps 15 to create an environment with sufficient temperature to attach the die 14 to the device 18.

7 and 9, once die 14 is permanently attached to device 18, plate 10 may be later removed by plate removal machine 300 at a later stage. Plate removal machine 300 may be another assembly machine, cleaning station, or other type of machine. For example, after mass production reflow in the heating chamber 200, the mounting device 18 can be transferred to the plate removal machine 300, and as shown in FIG. 7, the fluid 20 is returned to the vertical position to return the plate 20 to the plate ( When used to facilitate removal of 10), gravity can help remove plate 10 from die 14. This can occur at a plate removal station or location of the plate removal machine 300. The fluid 20 may or may not be needed depending on the embodiment. For example, simply moving the device 18 and plate 10 to a vertical position as shown in FIG. 7 may automatically remove the plate 10 due to gravity. Instead of turning vertically, the device 18 and plate 10 may alternatively be turned upside down as shown in FIG. 9. This embodiment also shows that fluid 20 is being used to help remove plate 10 from die 14.

In another embodiment, shown in FIGS. 8A-8C, a nozzle, such as nozzle 16, is used to detach plate 10 from die 14 and pick it up again after die 14 is attached to device 18. Can be configured. Alternatively, a nozzle other than the original nozzle 16 (not shown) can be used to remove the plate 10 from the die 14 and pick it up again after heating. Referring now to FIG. 10, plate removal machine 300 may include one or more removal nozzles, similar to application nozzle 16, to remove plate 10 from die 14. These removal nozzles can be used in addition to or instead of the gravity or fluid method described in FIGS. 7 and 9 above. In one embodiment, the removal nozzle can be configured to detect any plate 10 that has not been removed by other methods to remove the plate 10 that has not been removed. In other embodiments, the removal nozzle can be an exclusive removal mechanism and can be configured to pick up each plate 10 separately from its respective die 14.

It is understood that the process described above can be repeated as necessary to add additional layers on top of the first layer of the 3D TSV die 14. For example, a single die 14 can be applied as a bottom layer directly attached to device 18. The device 18 then performs an assembly machine 100 or other assembly machine (not shown) that performs the same process directly to attach the second die layer (not shown) directly on top of the first die 14. It can be arranged through. This second die can be attached to the first die 14 using a plate to retain the shape of the die in the same mass production reflow process and in the same manner as described above.

Thus, the TSV die 14 with the plate 10 can be mounted at significantly higher speeds than in the prior art process, and has a full mounting wafer / substrate or device 18 with all dies 14 and plates 10. ) The whole can be attached in a mass production reflow / bonding process without the risk of curling on individual dies 14 or potato chip effects. This process avoids the need to individually heat and cool the dies 14 at the time of or with a particular individual heating and cooling head. This can create significant cost savings for the assembly process of 3D TSV. The output of a $ 1 million assembly machine can be increased, for example, by 50 times. The method and assembly machine described above can also enable production of the same quantity and speed in a smaller clean room space.

In another embodiment, a layer of material may be attached to or otherwise applied to the bottom side of the plate 10 prior to contact with the die 14. This material can be flexible, adhesive, or provide enhanced friction to allow the plate 10 to better adhere to the die 14. Materials such as high temperature silicone rubber can be used for this purpose. These materials may be somewhat tacky to temporarily stick to the top of TSV die 14. These materials may be heat resistant and may not cause permanent fixation of die 14 and plate 10, but rather create only frictional forces during movement of device 18 in assembly machine 100 and heating chamber 200 It may help to hold the plate 10 in a suitable position on the die 14.

In another embodiment, it may be advantageous to keep the TSV die 14 flat to have a highly grounded surface and a precision ground that interfaces with the plate 10. The molecular attraction in this way can be the force that temporarily attaches the plate 10 to the die 14. Additionally, plate 10 may have recesses or pockets to prevent contact with non-flat areas or sensitive areas on top of die 14. For example, if the die 14 does not include a flat top surface to integrate with the plate 10, the plate 10 can be specially designed with a surface corresponding to the surface of the die 14.

The apparatus and method described above for attaching a die to a device may be used to attach the die to a substrate or other die.

The components of the embodiments were introduced with a negative article. The article is intended to mean that there is more than one component. The terms "comprising" and "having" and derivatives thereof are intended to be inclusive so that there may be additional components in addition to those listed. The conjunction “or” when used in an enumeration of at least two terms is intended to mean any term or combination of terms. The terms "first" and "second" are used to distinguish elements, and are not used to indicate a specific order.

Although the invention has been described in detail in connection with only a limited number of embodiments, it is readily understood that the invention is not limited to such disclosed embodiments. Rather, the present invention has not been described so far, but can be modified to incorporate any number of modifications, alterations, replacements, or equivalent arrangements corresponding to the spirit and scope of the present invention. Additionally, while various embodiments of the invention have been described, it is understood that aspects of the invention may include only some of the described embodiments. Therefore, the present invention is not intended to be limited by the above description, but is only limited by the appended claims.

Claims (20)

Picking up a plate comprising at least one opening from the assembly machine to the nozzle to allow air to flow through;
Picking up the die to the nozzle such that the plate is positioned between the nozzle and the die;
Placing the die and the plate on one of a device, substrate, or other die such that the plate is positioned on top of the die;
After the placement, transferring the one of the device, the substrate or the other die, and the die and the plate from the assembly machine to a heating chamber;
In the heating chamber while the plate remains on top of the die to permanently attach the die to the one of the device, the substrate, or the other die, and the one of the device, the substrate, or the other die. Heating the die;
After the heating, transferring the one of the device, the substrate or the other die, and the die and the plate to a plate removal machine; And
And removing the plate from the die through the plate removal machine. delete The method of claim 1, further comprising generating a vacuum between the plate and the die by removing air through the at least one opening by the nozzle. The method of claim 1, further comprising positioning the plate on the nozzle with a vision system prior to picking up the die. The plurality of dies of claim 1, wherein the die is configured to attach the die to the one of the device, the substrate or the other die during the heating of the device, the substrate or the other die in the heating chamber. A method comprising solder bumps. The method of claim 1, further comprising reusing the plate when placing the second die. The method of claim 1, further comprising attaching an adhesive layer to the surface of the plate positioned between the plate and the die, wherein the adhesive layer is configured to temporarily attach the plate to the die. . The method of claim 1, wherein the step of removing the plate from the die is such that the plate, the one of the device, the substrate, or the other die is separated from the die and the device, the substrate, or the other die. The method is achieved by vertically oriented. The method of claim 1, wherein removing the plate from the die is accomplished by picking up the plate from the die with a second nozzle. a) picking up a combination of the plate and the die from the assembly machine to the nozzle such that the plate is positioned between the die and the nozzle;
b) placing the combination of the plate and the die on one of a device, substrate, or other die;
c) repeating steps a) and b) to mount a plurality of combinations of the plate and the die on the one of the device, the substrate or the other die;
d) after the placement, the device, the one of the substrate or the other die, and the plate and the die in the heating chamber to attach each of the die to the one of the device, the substrate or the other die. Simultaneously heating a plurality of combinations; And
e) after the heating, removing each of the plates from each of the dies through a plate removal machine. The method of claim 10, further comprising generating a vacuum between each of the plurality of combinations of the die and the plate by removing air through openings located in each of the plates by the nozzle. 12. The method of claim 10, further comprising positioning each of the plates on the nozzle with a vision system prior to picking up each of the dies. The method of claim 10 further comprising reusing each of the plates. 12. The method of claim 10, further comprising attaching an adhesive layer to each surface of the plate positioned between the plate and the die for each of the plurality of combinations, wherein the adhesive layer attaches the plate to the die. The method is configured to temporarily attach to. 11. The method of claim 10, wherein removing each of the plates from each of the dies is such that each of the plates is separated from each of the dies and the device, the substrate, or the other die so that the device, the substrate Or by vertically orienting one of the other dies. 11. The method of claim 10, wherein removing each of the plates from each of the dies is achieved by picking each of the plates from each of the dies into at least one of the nozzle and the second nozzle. delete As an assembly system,
Assembly machine; And
A heating chamber,
The assembly machine,
The nozzle configured to pick up a combination of the plate and the die such that the plate is positioned between the nozzle and the die, the plate comprising at least one opening to allow air to flow through, and the plate at the first pick up location The nozzle being picked up and the die picked up at a second pick up location; And
A placement location for placing the combination of the plate and the die on one of the device, substrate or other die by the nozzle, the nozzle being placed on the plate and the device on the one of the device, the substrate or the other die It is configured to mount a plurality of the combination of the die, further comprising the placement site,
The heating chamber is used to attach the die to the one of the device, the substrate, or the other die while the plate remains on top of the die and the one of the device, the substrate, or the other die and the Configured to heat the die,
And a plate removal machine configured to remove the plate from the die. delete 19. The assembly system of claim 18, further comprising a plate recycling mechanism configured to clean the removed plate and provide the used plate to the first pick-up location.

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