A multi-die synchronous die mounting method
By modifying the machine structure and optimizing the wafer loading process, multiple wafer dies can be loaded and baked into the machine at the same time, which solves the problems of low production efficiency and material performance degradation in the existing technology, and improves product quality and reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANJING ZHENXIN RUNHE MICROELECTRONICS CO LTD
- Filing Date
- 2023-03-31
- Publication Date
- 2026-07-31
AI Technical Summary
Existing wafer mounting processes require multiple passes through the mounting machine and high-temperature baking, resulting in low production efficiency, degraded material properties, and product quality issues.
The machine structure was modified, multiple wafer mounting devices were added, and the guide rail control logic was adjusted to enable multiple wafer dies to be loaded and baked into the machine at one time. Multiple sets of dispensing and gripping integrated devices were used to work in parallel, optimizing the wafer loading process.
It improved production efficiency, reduced the impact of repeated high-temperature baking on materials, enhanced product quality and reliability, and shortened production time.
Smart Images
Figure CN116313918B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of semiconductor packaging technology, specifically a die attach process in electronic chip packaging technology. Background Technology
[0002] Die attach is an essential and crucial step in chip packaging. In this process, the die is removed from the diced wafer and bonded to its corresponding position on the substrate (or frame). The die and substrate are secured together using die attach material (DAM). DAM is typically a die attach film (DAF) or adhesive, usually an epoxy resin filled with inorganic powder (such as SiO2 or AG). For power devices, the bonding material between the die and frame may also be a highly thermally conductive alloy solder, such as solder. Figure 1 The diagram illustrates the wafer mounting process (this is for illustrative purposes only; the actual number of dies on a single wafer is far greater than shown in the diagram, and the wafer size is also much larger than the substrate size). After mounting, the mounted substrate is placed in an oven for high-temperature baking to solidify and set the DAM.
[0003] Figure 1 The die-packing process is for a single die package. If a package contains multiple dies, the die-packing and baking process needs to be repeated multiple times.
[0004] like Figure 2 The package shown contains two die chips. During the die bonding process, the first die chip (die 1) must be bonded first, baked, and cured, then the second die chip (die 2) must be bonded and baked, and the entire bonding process is then complete. If there are three die chips, the bonding and baking process is repeated three times; the number of bonding and baking cycles depends on the number of die chips. This bonding process is currently the common method in the chip packaging industry.
[0005] Taking the case of two wafer dies being packaged together as an example, a simplified diagram of the die-loading machine is shown below. Figure 3 and Figure 4 The commonly used machine structure and wafer loading process in the industry are as follows:
[0006] 1) The machine's operation mainly consists of three parts.
[0007] 1. Applying adhesive (drawing adhesive): Draw the outline of the adhesive on the correct position on the substrate;
[0008] 2. Die grabbing: The single die is cut in the wafer by using a push pin to lift it up, and then the die is grabbed (i.e., picked up) by a suction nozzle.
[0009] 3. Die bonding: The chip die is bonded to the corresponding position on the substrate (that is, the position with adhesive) by pressure, and the adhesive is pressed out and overflows to the periphery of the chip to form an effective bond.
[0010] 2) The machine has only one dispensing unit, one wafer table, and one die gripping and die placement unit. Therefore, the machine can only process one type of wafer at a time, that is, one die. If two dies are packaged together, they need to be fed into the machine track twice, if three dies are packaged together, they need to be fed into the machine track three times, and so on.
[0011] This mounting process has many drawbacks, such as:
[0012] 1) The die loading of each die in the same package cannot be completed at one time. It needs to be fed into the die loading machine multiple times and baked separately, which greatly reduces the production capacity UPH (output per hour), reduces the machine production efficiency, and lengthens the production time.
[0013] 2) Multiple feedings into the die-loading machine and repeated high-temperature baking can easily cause oxidation of the frame and the die-loading adhesive (the adhesive from the previous loading is baked multiple times), affecting the adhesive's performance. If it is solder-loading for power devices, oxidation of the frame and solder will seriously affect the loading performance of the remaining dies in subsequent secondary loadings.
[0014] 3) Repeated feeding into the die-loading machine and repeated high-temperature baking can easily cause oxidation and contamination of the substrate or frame, affecting the bonding force between the substrate or frame and the molding compound, thus leading to delamination. In addition, it can also cause substrate warping, affecting subsequent wire bonding and molding processes. Summary of the Invention
[0015] To address the above issues, this invention optimizes and improves the wafer loading process and equipment, enabling multiple wafer dies to be loaded onto the machine and baked in the oven in a single process, thus completing the entire wafer loading process faster and more efficiently.
[0016] A method for simultaneous multi-wafer loading, comprising the following steps:
[0017] First, modify the machine:
[0018] Extend the guide rails of the machine tool;
[0019] Multiple sets of wafer fabrication equipment are installed on the machine. Each set of wafer fabrication equipment includes a dispensing device, a wafer mounting stage, and a gripper and mounter integrated device. The nth dispensing device, the nth wafer mounting stage, and the nth gripper and mounter integrated device in the nth set of wafer fabrication equipment are defined, where n is a natural number.
[0020] Along the substrate's forward direction, the guide rail is divided into a dispensing area and a wafer mounting area. In the dispensing area, the first to n dispensing devices are arranged sequentially along the substrate's forward direction. In the wafer mounting area, the first to n integrated gripping and bonding devices are arranged sequentially along the substrate's forward direction. Next to the guide rail, the first to n wafer mounting stages are arranged sequentially, and their positions correspond to the first to n integrated gripping and bonding devices, respectively.
[0021] The dispensing device is used to apply the cured die bonding material onto the substrate; the wafer placement stage is used to place the wafer; the gripper and place device grips the die on the corresponding wafer and then places it on the substrate at the corresponding dispensing position.
[0022] definition:
[0023] Workstation: The location of the first to n dispensing devices and the first to n gripping and bonding devices is the corresponding workstation; the spacing between two adjacent workstations is the same;
[0024] Micro-stepping: During the operation at the same workstation, the substrate moves forward with the guide rail in a single step as required by the current operation. The number of micro-steps during a single operation at the same workstation can be 0, 1, or more.
[0025] Macro stepping: After a single operation at the same workstation is completed, the substrate moves forward along the guide rail to the next workstation, which is called macro stepping.
[0026] Then, the guide rail forward control logic was revised:
[0027] If all workstations have substrates in operation, the guide rail will take one macro step after all the substrates in all workstations have completed their respective operations.
[0028] If there is no substrate being processed at a workstation, the guide rail will be macrostepped once after all workstations with substrates being processed have completed their operations.
[0029] Next, each set of mounting equipment performs the mounting operation:
[0030] For a single type of wafer die, it is operated by the same wafer fabrication equipment;
[0031] The substrate moves along the guide rail to the station of the nth dispensing device, and the nth dispensing device begins operation. According to the guide rail advance control logic, the substrate moves along the guide rail to the station of the nth gripping and bonding device. The nth gripping and bonding device picks up the wafer die from the nth wafer mounting stage, places it in the corresponding dispensing position, and then flattens it.
[0032] Finally, the baking process is carried out: the substrate with all the wafer dies installed is sent into the oven to cure the die bonding material.
[0033] illustrate:
[0034] 1) The distance between two adjacent dispensing units is relatively large. The dispensing unit is more macroscopic than the substrate. For example, the distance between the first dispensing unit and the second dispensing unit is greater than the length of a substrate. One dispensing unit processes one substrate at a time.
[0035] 2) Similar to the dispensing device, the gripping and bonding device corresponds to one substrate at the same time point.
[0036] 3) If n dispensing devices work together, and each dispensing device processes one substrate, then there are n substrates being dispensed.
[0037] If n integrated gripper and bonding devices work together, each device will process one substrate, resulting in n substrates being bonded.
[0038] The total number of substrates currently in operation on the track is 2n.
[0039] 4) Within the same set of substrate preparation equipment, the number of substrates dispensed and the dispensing position of the dispensing device on the substrate are adjusted according to product requirements, and the number of substrates and the placement position of the corresponding gripper and bonding device are adjusted accordingly. For example, under current technology, one dispensing (or bonding) device processes one substrate, and after dispensing (or bonding) two columns on the substrate, it moves forward one micro-step along the guide rail. Therefore, one dispensing (or bonding) device makes multiple micro-steps during the process of working on one substrate.
[0040] Under current technology, production line equipment typically moves forward once every two rows of substrates. These two rows are equivalent to micro-stepping. However, these two rows contain many products, meaning the positions requiring dispensing and chip mounting differ. Within these two rows, dispensing and chip mounting are achieved through the movement of the dispensing head / grip head of the dispensing / grip unit itself. After these two rows are completed, the track performs one micro-step, moving the substrate forward two rows, and the dispensing head / grip head continues its work within these two rows.
[0041] Further:
[0042] a. If the wafer dies on the substrate are stacked (single stack), then:
[0043] First, the mounting operation is performed on the machine. After the bottom chip die is mounted, it is sent into the oven for baking.
[0044] Then, the substrate obtained in the previous step is sent back to the machine for mounting. A layer of wafer dies is mounted and sent to the oven for baking. The dispensing device is located on the top surface of the next layer of wafers. This process is repeated until all the upper layer wafers are mounted.
[0045] b. For a substrate with multiple stacked wafer dies, where each stacked wafer die is laid flat on the substrate:
[0046] First, the mounting operation is carried out on the machine. After mounting each underlying chip die, it is sent into the oven for baking.
[0047] Then, the substrate obtained in the previous step is sent back to the machine for mounting. After each upper layer die is mounted, it is sent to the oven for baking. The dispensing device is on the top surface of each lower layer die. This process is repeated until all the upper layers of the stacked die are mounted.
[0048] c. If the wafer dies on the substrate are laid out in a flat manner; and the number of wafer die types on the substrate is q, where q > n, then: the mounting operation is performed in multiple steps, with each mounting operation mounting n wafer die types, and the last mounting operation mounting the remaining wafer die types; finally, a baking operation is performed.
[0049] Furthermore, the dispensing device dispenses adhesive evenly across the substrate surface.
[0050] If the cured substrate bonding material is a substrate adhesive, then each dispensing device operates during the substrate mounting process;
[0051] If the curing adhesive material is a film, then during the mounting process, the dispensing devices will not operate.
[0052] In the prior art, the top surface of the bottom chip die is covered with a DAF film. The DAF film is built into the back of the chip. A DAF film is attached to the back of the entire wafer. After the wafer is cut into chips, the DAF film is also cut and attached to the back of the chip.
[0053] To make it easier to understand, let's take an example with 3 usage scenarios and 2 usage logics for the machine:
[0054] Use cases:
[0055] A. When the package contains only one type of die, the two die-casting units (including dispensing and gripping units) process the substrate in sections. For example, unit 1 processes the first half of the substrate. After completion, this substrate moves to unit 2 to process the remaining second half of the substrate (note that units 1 and 2 are far apart and do not process the same substrate simultaneously; there is a time sequence). The machine efficiency is doubled.
[0056] B. When the package contains two types of dies, die1 and die2, and they are laid flat rather than stacked, each set of equipment (including the dispensing unit and the gripping unit) is responsible for processing only one die. The first set of equipment processes die1, and the second set of equipment processes die2. The machine completes the loading of two dies in one pass along the track, doubling the efficiency. Of course, die1 needs to meet the requirements for DAF film loading.
[0057] C. When the package contains two types of dies, die1 and die2, stacked one on top of the other, the machine cannot load both dies in one pass because die2 needs to be stacked on top of die1. It can only load die1 on the first pass and die2 on the second. However, the first pass is equivalent to processing only one die, which can be considered scenario A; the second pass is also equivalent to processing only one die, which can be considered scenario A. This effectively doubles the efficiency.
[0058] Using logic:
[0059] ① When different die-loading devices process different dies, one set of equipment can process one substrate completely. This usage logic corresponds to scenario B above.
[0060] ② When different die-loading devices process the same die, one set of devices processes a portion of the substrate (if there are a total of 2 sets of devices, then one set of devices processes half of the substrate). This logic corresponds to scenarios A and C above.
[0061] This improved mounting method has many advantages:
[0062] 1) Multiple dies in the same package can be loaded into the track at once, which greatly improves UPH, increases machine production efficiency, and shortens production time.
[0063] 2) If it is a single die package, it can also pick up and load dies for multiple wafers (e.g., two wafers) at the same time, achieving several times the production efficiency, similar to the effect of machine expansion.
[0064] 3) Multiple dies within the same package do not need to be fed into the machine track multiple times or baked at high temperatures, thus avoiding DAM oxidation caused by multiple high-temperature baking, which affects performance and improves the reliability of the material.
[0065] 4) Multiple dies within the same package do not need to be fed into the machine track multiple times and baked at high temperatures multiple times. This avoids warping, deformation, oxidation, and contamination of the substrate or frame caused by multiple high-temperature baking, which would affect subsequent wire bonding and molding processes, thus improving product quality and reliability. Attached Figure Description
[0066] Figure 1This is a schematic diagram of the die packaging process for a single chip in the existing technology;
[0067] Figure 2 This is a schematic diagram of the die-packing process for two-chip dies in existing technology;
[0068] Figure 3 yes Figure 2 A schematic diagram of the first wafer die loading process on the wafer mounting machine.
[0069] Figure 4 yes Figure 2 A schematic diagram of the second wafer die loading process;
[0070] Figure 5 This is a schematic diagram of the die-packing process for two wafer dies according to an embodiment of the present invention;
[0071] Figure 6 This is a schematic diagram of the dispensing process according to an embodiment of the present invention;
[0072] Figure 7 This is a schematic diagram of the patching process according to an embodiment of the present invention. Detailed Implementation
[0073] The present invention will now be described in conjunction with the accompanying drawings and specific embodiments.
[0074] refer to Figure 5 Take, for example, a machine with two sets of wafers.
[0075] 1) Improve and upgrade the existing wafer mounter structure and components. Add a dispensing device, a wafer table (wafer placement stage), and a die gripping and die placement device (integrated gripping and placement device). Appropriate adjustments to the machine track are needed, such as increasing the track length; the machine's operating logic function needs to be modified so that the two devices can work in parallel reasonably. These can all be achieved by adjusting the control program according to the wafer mounter process.
[0076] 2) Select products that meet the requirements for wafer mounting (such as common packages containing two different dies in a flat arrangement), place the wafers corresponding to the two dies into the first and second wafer mounting stages (wafer table 1 and wafer table 2) respectively, send the substrate into the machine track, start the first and second dispensing devices (dispensing device 1 and dispensing device 2), and start the first and second gripping and bonding integrated devices (die gripping and bonding device 1 and die gripping and bonding device 2).
[0077] 3) Dispensing device 1 is responsible for dispensing adhesive to the die1 area of the entire substrate, and dispensing device 2 is responsible for dispensing adhesive to the die2 area of the entire substrate. (For ease of understanding, Figure 5In the process, there are two substrates in the dispensing area on the track, one below dispensing device 1 and the other below dispensing device 2. Dispensing device 1 is responsible for dispensing glue to the die1 area of the substrate. After the die1 area on the substrate is finished, the substrate moves to the area below dispensing device 2, and dispensing continues to the die2 area on the substrate. At this time, dispensing device 1 begins to dispense glue to the die1 area of the next substrate 2.
[0078] Die-grabbing and die-attaching device 1 picks up die 1 from wafer table 1 and attaches die 1 to the die 1 area of the entire substrate. Die-grabbing and die-attaching device 2 picks up die 2 from wafer table 2 and attaches die 2 to the die 2 area of the entire substrate. The logic and operation are the same as the dispensing device above. The entire substrate area is now fully loaded. Note that each device is responsible for completing one substrate.
[0079] Generally, a single dispensing device can only dispense adhesive to a specific type of die, and cannot dispense adhesive to different types of dies. This is because the dispensing shape and amount may differ for each type of die, which can be determined by setting the parameters of each dispensing device. Therefore, a substrate is only processed in two ways when there is only one type of die on the entire substrate. That is, dispensing device 1 is responsible for one half of the substrate, and dispensing device 2 is responsible for the other half (e.g., ...). Figure 6 This increases the dispensing rate.
[0080] 4) Place the mounted substrate into an oven for high-temperature baking to cure the DAM and form a stable bond. The mounting process is now complete.
[0081] like Figure 5 As shown, this example, after the machine modification, is equipped with two dispensing units, two die gripping and die placement units, and two wafer tables, enabling it to complete the mounting of two dies within a package in a single pass through the track. Specifically, this modified machine can be applied to the following scenarios:
[0082] 1) When the package contains two dies, and the two dies are laid flat (not stacked), the die attach material (DAM) can be either DAF film (die attach film) or die attach adhesive. The die attach process can be performed using... Figure 5 The diagram shows the assembly of two dies in one step. This corresponds to scenario B above, logic ①.
[0083] 2) When the package contains 2 dies, and the two dies are stacked.
[0084] This dual-die stacked structure is a reference for the mounting process. Figure 6 and Figure 7The pattern is as follows: for die1, one orbital pass, two sets of devices operate on one half of the substrate respectively; for die2, one orbital pass, two sets of devices operate on one half of the substrate respectively. Efficiency is doubled. This corresponds to scenario C, logic ② mentioned above.
[0085] 3) When the package contains ≥3 dies, if each die is in a flat configuration, then... Figure 5 The diagram shows a single-stage encapsulation of two dies, but each die needs to be split. For example, when three dies are laid flat and encapsulated, it needs to be split into a 2-die + 1-die encapsulation, meaning that two dies are first processed... Figure 5 The single-pass wafer loading shown corresponds to logic ① above. The third die then undergoes another loading process via the track. Thus, the entire wafer loading process requires two track passes, but this is still more efficient than the traditional method which requires three track passes. When loading the third die separately, logic ② can be activated to speed up the loading process. For four dies, this can be split into two loading passes (2 dies + 2 dies) to minimize the number of track passes. If more dies are laid out flat, the same principle applies to minimize the number of track passes.
[0086] 4) When the package contains ≥3 dies, if the package simultaneously has die stacking and flattening, the stacked die structure uses... Figure 6 and Figure 7 Style, i.e., logic ②; two dies in a tiled structure can be used. Figure 5 As shown, logic ① completes the loading of two dies in one go. When there are too many dies, the loading process needs to be effectively split according to the actual situation to minimize the number of times the dies enter the machine track.
[0087] It is important to note that
[0088] a. When the two dies (die1, die2) to be processed are not stacked vertically, the two die-loading devices of the machine can process die1 / die2 simultaneously in one pass.
[0089] b. When the two dies to be processed are stacked one on top of the other, it is not possible to process both dies at the same time in one go (because die1 must be applied before die2 can be applied). However, for die1 or die2, two sets of equipment can perform regional operations on the substrate, achieving twice the work efficiency.
[0090] 5) When the package contains only one die, the machine structure and process can also be used (i.e., logic ② above).
[0091] 1. Dispensing devices 1 and 2 operate in separate zones, each responsible for dispensing adhesive to different areas of the substrate. For example, dispensing device 1 might be responsible for dispensing adhesive to the first half of the substrate, while dispensing device 2 might be responsible for dispensing adhesive to the second half. Alternatively, the dispensing area can be divided into staggered zones, alternating between every other column or several columns. Figure 6 As shown, the substrate is dispensing adhesive in alternating columns and sections. Dispensing device 1 is responsible for dispensing adhesive to half of the substrate area, and dispensing device 2 is responsible for dispensing adhesive to the remaining half of the substrate area. Using this method, the dispensing speed is twice that of using only one dispensing device.
[0092] 2. Wafer table 1 and wafer table 2 carry the same wafer, and the two wafers can be used for die processing at the same time.
[0093] 3. The die grabbing and die placing devices 1 and 2 operate in separate areas. Device 1 grabs a die from wafer table 1 and places it on a certain area of the substrate, while device 2 grabs a die from wafer table 2 and places it on another area of the substrate. For example, die grabbing and die placing device 1 is responsible for placing dies on the first half of the substrate, and die grabbing and die placing device 2 is responsible for placing dies on the second half of the substrate. Alternatively, the areas can be divided into staggered sections, such as every other column or several columns, for die placing.
[0094] like Figure 7 As shown, the substrate is mounted in alternating columns, with die gripping and placement unit 1 handling half of the substrate area and die gripping and placement unit 2 handling the remaining half. Using this method, the die placement speed is twice that of a single die gripping and placement unit. Thus, by adding a dispensing unit, a wafer table, and die gripping and placement units, the production efficiency is effectively doubled, similar to expanding the machine's capacity, but with a much lower investment than a single machine and no additional space required. It is very convenient to use; any unnecessary units can be shut down and left idle when not in use.
[0095] 6) The machine can also be equipped with a third set of dispensing equipment, a wafer table, and a die gripping and die placement device, enabling the loading of 3 dies at a time into the machine track. However, if the number of loading devices increases too much, the complexity of the machine system logic increases, and if the loading speed and efficiency are increased too much, other unknown problems may arise.
[0096] For existing mainstream products and mature equipment, using two sets of wafer mounting equipment is more economical. With technological advancements, the equipment and wafer mounting process can be further improved based on the ideas presented in this method.
Claims
1. A multi-die synchronous die attach method, Its characteristics are First, modify the machine: Extend the guide rails of the machine tool; Multiple sets of wafer fabrication equipment are installed on the machine. Each set of wafer fabrication equipment includes a dispensing device, a wafer mounting stage, and a gripper and mounter integrated device. The nth dispensing device, the nth wafer mounting stage, and the nth gripper and mounter integrated device in the nth set of wafer fabrication equipment are defined, where n is a natural number. Along the substrate's forward direction, the guide rail is divided into a dispensing area and a wafer mounting area. In the dispensing area, the first to n dispensing devices are arranged sequentially along the substrate's forward direction. In the wafer mounting area, the first to n integrated gripping and bonding devices are arranged sequentially along the substrate's forward direction. Next to the guide rail, the first to n wafer mounting stages are arranged sequentially, and their positions correspond to the first to n integrated gripping and bonding devices, respectively. Dispensing devices are used to apply and cure adhesive materials for sheet bonding. The wafer mounting stage is used to place wafers; the gripper and place device grips the die on the corresponding wafer and then places it on the substrate at the corresponding dispensing position. definition: Workstation: The location of the first to n dispensing devices and the first to n gripping and bonding devices is the corresponding workstation; the spacing between two adjacent workstations is the same; Micro-stepping: During the operation at the same workstation, the substrate moves forward with the guide rail in a single step as required by the current operation. The number of micro-steps during a single operation at the same workstation can be 0, 1, or more. Macro stepping: After a single operation at the same workstation is completed, the substrate moves forward along the guide rail to the next workstation, which is called macro stepping. Then, the guide rail forward control logic was revised: If all workstations have substrates in operation, the guide rail will take one macro step after all the substrates in all workstations have completed their respective operations. If there is no substrate being processed at a workstation, the guide rail will be macrostepped once after all workstations with substrates being processed have completed their operations. Next, each set of mounting equipment performs the mounting operation: For a single type of wafer die, it is operated by the same wafer fabrication equipment; The substrate moves along the guide rail to the station of the nth dispensing device, and the nth dispensing device begins operation. According to the guide rail advance control logic, the substrate moves along the guide rail to the station of the nth gripping and bonding device. The nth gripping and bonding device picks up the wafer die from the nth wafer mounting stage, places it in the corresponding dispensing position, and then flattens it. Finally, the baking process is carried out: the substrate with all the wafer dies installed is sent into the oven to cure the die bonding material.
2. A multi-wafer synchronous wafer loading method according to claim 1, characterized by The wafer dies on the substrate are stacked. The bottom layer of the stack is defined as the bottom wafer, and all wafers above the bottom wafer are called upper wafers. There can be one or more upper wafers. Therefore: First, the mounting operation is performed on the machine. After the bottom chip die is mounted, it is sent into the oven for baking. Then, the substrate obtained in the previous step is sent back to the machine for mounting. After mounting a layer of wafer dies, it is sent to the oven for baking. During this process, the dispensing device applies adhesive to the top surface of the next layer of wafers. This process is repeated until all the upper-layer wafers are mounted.
3. The multi-wafer synchronous wafer loading method of claim 1 wherein If there are multiple stacked wafer dies on the substrate, and each stacked wafer die is laid flat on the substrate, then: First, the mounting operation is carried out on the machine. After mounting the bottom layer die in each stacked form, it is sent into the oven for baking. Then, the substrate obtained in the previous step is sent back to the machine for mounting. After each upper layer of wafer die is mounted, it is sent to the oven for baking. During this process, the dispensing device applies adhesive to the top surface of each lower layer wafer. This process is repeated until all upper layers of wafer dies in each stacked configuration are mounted.
4. The multi-wafer synchronous wafer loading method of claim 1 wherein The wafer dies on the substrate are laid out in a flat manner; the number of types of wafer dies on the substrate is q, q>n, then: the mounting operation is performed in multiple times, each mounting operation mounts n types of wafer dies, and the last mounting operation mounts the remaining number of types of wafer dies; finally, a baking operation is performed.
5. The multi-wafer synchronous wafer loading method of claim 1 wherein The same dispensing device dispenses adhesive evenly across the substrate surface.
6. The multi-die synchronous die attach method of claim 1, Its characteristics are If the cured substrate bonding material is a substrate adhesive, then each dispensing device operates during the substrate mounting process; If the curing adhesive material is a film, then during the mounting process, the dispensing devices will not operate.