Chip packaging method and chip packaging structure
By forming high-modulus and low-modulus adhesive layers in the edge area of the substrate and combining the boss design, the problems of 2.5D product warpage and underfill glue layering are solved, and the product warpage is reduced and reliability is improved without adding additional costs.
Patent Information
- Application Number
- CN202510703985.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-29
- Publication Date
- 2025-09-05
AI Technical Summary
The prior art has difficulties in controlling warping and underfill glue layering of 2.5D products. Although the high-modulus reinforcement sheet bonding glue can control warping, it leads to delamination problems, while the low-modulus glue cannot effectively control warping.
A high-modulus adhesive layer and a low-modulus adhesive layer are formed in the edge area of the substrate, corresponding to the weak stress and strong stress areas of the reinforcement sheet respectively, and the reinforcement sheet is fixed by glue layers of different modulus, combined with the boss design to release stress, improve warpage and prevent the underfill layer from delamination.
It effectively reduces product warpage by approximately 100μm and reduces the delamination rate of the underfill layer from 44% to 0%, improving product reliability while saving costs without the need for additional investment in new equipment and processes.
Smart Images
Figure CN120600642A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present disclosure belong to the field of semiconductor packaging technology, and particularly relate to a chip packaging method and a chip packaging structure. Background Art
[0002] In order to control the warping of 2.5D products and the delamination of the underfill glue, the industry currently adopts the method of mounting reinforcement sheets around the substrate. The main process is: 1) Applying high modulus reinforcement sheet glue around the substrate; 2) Automatically mounting metal reinforcement sheets; 3) Reinforcement sheet curing: Using special fixtures to maintain a certain pressure / temperature / time on the reinforcement sheet. Among them, the purpose of applying a certain pressure is to improve the warping of the product and press the product as flat as possible. The greater the pressure, the better the warping; the purpose of adding temperature and time is to cure the glue, which can keep the product warping at a relatively good level under the action of the reinforcement sheet; 4) The product warping and underfill glue delamination caused by the high-temperature process of the 2.5D product are guaranteed by curing the interface between the reinforcement sheet glue and the metal reinforcement sheet.
[0003] As product sizes get larger, product warpage also gets larger. When choosing adhesive for reinforcement sheets, you need to use high-modulus adhesive to control product warpage. During the curing process of the reinforcement sheet, greater pressure is required to improve the warpage of the product, but the greater the pressure on the reinforcement sheet, the thickness of the reinforcement sheet glue will decrease. When the glue thickness is less than 40um, the product will have the problem of reinforcement sheet delamination due to stress after reliability. Using low-modulus reinforcement sheet adhesive can effectively improve the above-mentioned problem of reinforcement sheet delamination caused by stress after reliability, but the warpage of the product at high temperature cannot be guaranteed; using high-modulus reinforcement sheet adhesive can effectively control the warpage caused by the product in the high-temperature process, but because the product stress is not released, it will cause the bottom fill glue of the 4 corners of the 2.5D product to delaminate.
[0004] In view of the above problems, it is necessary to propose a chip packaging method and a chip packaging structure that are reasonably designed and effectively solve the above problems. Summary of the Invention
[0005] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a chip packaging method and a chip packaging structure.
[0006] An aspect of an embodiment of the present disclosure provides a chip packaging method, comprising:
[0007] Provide chips, substrates and reinforcement sheets separately;
[0008] flip-chip mounting the chip on the substrate;
[0009] forming an underfill layer between the chip and the substrate;
[0010] forming a high modulus adhesive layer at an edge region of the substrate corresponding to a weak stress region of the reinforcing sheet;
[0011] forming a low modulus adhesive layer at an edge region of the substrate corresponding to a strong stress region of the reinforcing sheet;
[0012] The reinforcing sheet is fixed to the substrate through the high modulus adhesive layer and the low modulus adhesive layer respectively.
[0013] Optionally, a plurality of spaced bosses are provided on a side of the reinforcing sheet facing the base plate;
[0014] The boss is used to ensure that the adhesive layer formed between the reinforcing sheet and the base plate has a preset thickness.
[0015] Optionally, the height of the boss ranges from 55 μm to 65 μm.
[0016] Optionally, forming a high modulus adhesive layer in an edge area of the substrate corresponding to a weak stress area of the reinforcing sheet includes:
[0017] High modulus glue is spot-coated on the edge area of the substrate and corresponding to each side edge of the reinforcement sheet to form the high modulus glue layer.
[0018] Optionally, the distance between the ends of two adjacent high modulus adhesive layers ranges from 8 mm to 10 mm.
[0019] Optionally, forming a low modulus adhesive layer in an edge area of the substrate corresponding to a high stress area of the reinforcing sheet includes:
[0020] Low modulus glue is spot-coated on the edge area of the substrate and at each corner end corresponding to the reinforcement sheet to form the low modulus glue layer.
[0021] Optionally, fixing the reinforcing sheet to the substrate through the high modulus adhesive layer and the low modulus adhesive layer respectively includes:
[0022] A preset pressure and a preset temperature are applied to the reinforcing sheet to solidify the high modulus adhesive layer and the low modulus adhesive layer, thereby fixing the reinforcing sheet to the substrate.
[0023] Another aspect of the embodiments of the present disclosure provides a chip packaging structure, including a chip, a substrate, a reinforcement sheet, an underfill layer, a high modulus adhesive layer, and a low modulus adhesive layer;
[0024] The chip is flip-chip mounted on the substrate;
[0025] The underfill layer is disposed between the substrate and the chip and wraps the bumps of the chip;
[0026] The reinforcing sheet is fixed to the edge area of the substrate;
[0027] The high modulus adhesive layer is disposed between each side edge of the reinforcing sheet and the substrate;
[0028] The low modulus adhesive layer is arranged between each corner end of the reinforcing sheet and the base plate.
[0029] Optionally, a plurality of spaced bosses are provided on a side of the reinforcing sheet facing the base plate;
[0030] The boss can ensure that the adhesive layer between the reinforcing sheet and the base plate has a preset thickness.
[0031] Optionally, the height of the boss ranges from 55 μm to 65 μm.
[0032] The chip packaging method and chip packaging structure of the embodiments of the present disclosure, in which a high modulus adhesive layer is formed in the edge area of the substrate and corresponds to the weak stress area of the reinforcement sheet; a low modulus adhesive layer is formed in the edge area of the substrate and corresponds to the strong stress area of the reinforcement sheet, and then the reinforcement sheet is fixed to the substrate by the high modulus adhesive layer and the low modulus adhesive layer respectively. The stress release of the product during the high-temperature curing process is improved by the adhesive layers with different moduli, which can not only improve the warping of the product but also ensure that the bottom filling layer does not delaminate. The warping of the product can be reduced by about 100 μm, and the incidence of delamination of the bottom filling layer is reduced from 44% to 0%, thereby greatly improving the reliability of the product. In addition, the chip packaging method can continue to use the existing packaging process without additional investment in new equipment and processes, thus saving costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1 This is a schematic flow chart of a chip packaging method according to one embodiment of the present disclosure;
[0034] Figures 2 to 6 Schematic diagram of a process flow of a chip packaging method according to another embodiment of the present disclosure;
[0035] Figure 7 This is a curve diagram of improving product warpage using the chip packaging method of this embodiment according to another embodiment of the present disclosure. DETAILED DESCRIPTION
[0036] In order to enable those skilled in the art to better understand the technical solutions of the embodiments of the present disclosure, the embodiments of the present disclosure are further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0037] like Figure 1As shown, one aspect of an embodiment of the present disclosure provides a chip packaging method S100, including:
[0038] S110 , providing a chip, a substrate, and a reinforcement sheet respectively.
[0039] like Figure 2 and Figure 5 As shown, a chip 110, a substrate 120 and a reinforcing sheet 140 are provided. In this embodiment, the reinforcing sheet 140 is in a rectangular ring shape and is used to be fixed to the edge area of the substrate 120 to prevent the substrate 120 from warping.
[0040] S120, flip-chip mounting the chip on the substrate.
[0041] like Figure 2 As shown, the chip 110 is flip-chip mounted on the central area of the substrate 120 .
[0042] S130 , forming an underfill layer between the chip and the substrate.
[0043] like Figure 2 As shown, an underfill is filled between the chip 110 and the substrate 120 to form an underfill layer 130 .
[0044] S140 , forming a high modulus adhesive layer in an edge area of the substrate corresponding to a weak stress area of the reinforcing sheet.
[0045] Specifically, in this embodiment, it can be seen from the simulation cloud diagram that the stress on the four sides of the reinforcing sheet 140 is relatively small. Figure 3 As shown, high modulus glue (greater than 80Mpa) is applied to the edge area of the substrate 120 and the sides of the corresponding reinforcing sheet 140 to form a high modulus glue layer 150. Figure 3 As shown, in this embodiment, the high modulus adhesive layer 150 is I-shaped.
[0046] For example, the distance between the ends of two adjacent high modulus adhesive layers 150 ranges from 8 mm to 10 mm. Preferably, in this embodiment, the distance between the ends of two adjacent high modulus adhesive layers 150 is 10 mm, leaving enough space for the painting glue of low modulus glue.
[0047] In this embodiment, a high modulus adhesive layer is formed in the weak stress area of the reinforcement sheet, and a greater pressure needs to be applied during the curing process of the reinforcement sheet to more effectively control the warping of the product caused by high temperature.
[0048] S150 , forming a low modulus adhesive layer in an edge area of the substrate corresponding to a high stress area of the reinforcing sheet.
[0049] Specifically, in this embodiment, it can be seen from the simulation cloud map that the areas with the greatest stress on the reinforcement sheet 140 are at its four corners. Figure 3 As shown, low modulus glue (less than 20 MPa) is applied to the edge area of the substrate 120 and at each corner end of the corresponding reinforcing sheet 140 to form a low modulus glue layer 160. Figure 3 As shown, in this embodiment, the low modulus adhesive layer 160 is L-shaped, matching the shape of each corner end of the reinforcing sheet 140 .
[0050] In this embodiment, a low modulus adhesive layer is formed in the strong stress area of the reinforcement sheet, which can release the stress of the product during the curing process of the reinforcement sheet, avoid the delamination problem of the underfill layer, and improve the reliability of the product.
[0051] S160 , fixing the reinforcing sheet to the substrate through the high modulus adhesive layer and the low modulus adhesive layer respectively.
[0052] Specifically, if Figure 4 As shown, after the dispensing of the high modulus glue and the low modulus glue is completed, the reinforcing sheet 140 is placed on the formed high modulus glue layer 150 and the low modulus glue layer 160, as shown in FIG. Figure 6 As shown, a preset pressure and a preset temperature are then applied to the reinforcing sheet 140 to cure the high modulus adhesive layer 150 and the low modulus adhesive layer 160, thereby fixing the reinforcing sheet 140 to the substrate 120. During the process of applying the preset pressure and the preset temperature to the reinforcing sheet 140, the high modulus adhesive layer 150 and the low modulus adhesive layer 160 are connected.
[0053] Exemplarily, after the reinforcing sheet 140 is fixed to the substrate 120, the method further includes:
[0054] A plurality of solder balls are formed on a side of the substrate 120 facing away from the chip 110 to form a 2.5D chip packaging structure.
[0055] It should be noted that the chip packaging method of the embodiment of the present disclosure can also be used in the packaging process of a 3D chip packaging structure, as long as it can improve the warping of the product and control the delamination of the bottom filling layer and improve the delamination of the reinforcement sheet glue.
[0056] The chip packaging method of the embodiment of the present disclosure forms a high-modulus adhesive layer in the edge area of the substrate and corresponding to the weak stress area of the reinforcement sheet; forms a low-modulus adhesive layer in the edge area of the substrate and corresponding to the strong stress area of the reinforcement sheet, and then fixes the reinforcement sheet to the substrate through the high-modulus adhesive layer and the low-modulus adhesive layer respectively. The stress release of the product during the high-temperature curing process is improved by the adhesive layers with different moduli, which can not only improve the warping of the product but also ensure that the bottom fill adhesive layer is not delaminated.
[0057] For example, Figure 5As shown, a plurality of spaced-apart bosses 141 are provided on one side of the reinforcing sheet 140 facing the base plate 120 .
[0058] When securing the reinforcing sheet 140 to the substrate 120, the side with the boss 141 is attached to the substrate 120. This creates a gap between the reinforcing sheet 140 and the substrate 120 due to the presence of the boss 141, thereby ensuring that the high-modulus adhesive layer 150 and the low-modulus adhesive layer 160 have a predetermined thickness. This prevents delamination of the adhesive when pressure is applied to the reinforcing sheet 140 to improve product warpage, as the high-modulus adhesive layer 150 and the low-modulus adhesive layer 160 have predetermined thicknesses, thereby improving product reliability.
[0059] Exemplarily, the height of the boss 141 ranges from 55 μm to 65 μm. Preferably, in this embodiment, the height of the boss 141 is 60 μm. Through simulations, the effect of the thickness of the high-modulus adhesive layer 150 and the low-modulus adhesive layer 160 on stress / warpage was confirmed. Selecting a thickness of 60 μm for the high-modulus adhesive layer 150 and the low-modulus adhesive layer 160 minimizes the impact on product warpage and stress. In other words, the height of the boss 141 is selected to be 60 μm.
[0060] It should be noted that the shape of the bosses 141 is not specifically limited and can be rectangular, circular, or other shapes, and can be selected according to actual needs. It should be further noted that the distribution position of the bosses 141 is also not specifically limited. For example, the bosses 141 can be distributed at intervals on the four sides of the reinforcing sheet 140, or can be set at the four corners of the reinforcing sheet 140, and can be selected according to actual needs.
[0061] In this embodiment, a plurality of bosses are provided on the side of the reinforcing sheet facing the substrate, which can not only ensure a sufficiently large reinforcing sheet mounting pressure to improve product warping, but also ensure that the high modulus adhesive layer and the low modulus adhesive layer have a preset thickness due to the action of the bosses, and will not cause delamination of the reinforcing sheet glue, thereby improving product reliability.
[0062] As shown in Table 1, data on underfill layer delamination was collected after a high-temperature process for a chip package structure formed using the chip packaging method S100 of the present application. As shown in Table 1, when the height of the protrusion 141 was between 55 μm and 65 μm, the underfill layer 130 did not delaminate after multiple high-temperature reflows. This reduced the occurrence rate of underfill layer 130 delamination from 44% to 0%, significantly improving the reliability of the chip package structure.
[0063] like Figure 7As shown, Leg1 is the process without boss reinforcement sheet and full high modulus glue, Leg2 / 3 / 4 is the process of implementing this solution: through the implementation of this solution, Figure 7 It can be seen that the chip packaging method of the present application can reduce the warping of the chip packaging structure by about 100um, thereby improving the reliability of the chip packaging structure.
[0064] Table 1 Data collection of underfill layer delamination after high temperature process
[0065]
[0066] The chip packaging method of the embodiment of the present disclosure forms a high-modulus adhesive layer in the edge area of the substrate and corresponding to the weak stress area of the reinforcement sheet; forms a low-modulus adhesive layer in the edge area of the substrate and corresponding to the strong stress area of the reinforcement sheet, and then fixes the reinforcement sheet to the substrate through the high-modulus adhesive layer and the low-modulus adhesive layer respectively. The stress release of the product during the high-temperature curing process is improved by the adhesive layers with different moduli, which can not only improve the warping of the product but also ensure that the bottom fill layer does not delaminate. Among them, the warping of the product can be reduced by about 100 μm, and the incidence of delamination of the bottom fill layer is reduced from 44% to 0%, thereby greatly improving the reliability of the product. In addition, the chip packaging method can continue to use the existing packaging process without additional investment in new equipment and processes, saving costs.
[0067] like Figure 6 As shown, another aspect of the embodiment of the present disclosure provides a chip packaging structure, including a chip 110 , a substrate 120 , an underfill layer 130 , a reinforcing sheet 140 , a high modulus adhesive layer 150 and a low modulus adhesive layer 160 .
[0068] The chip 110 is flip-chip mounted on the substrate 120 .
[0069] The underfill layer 130 is disposed between the substrate 120 and the chip 110 and wraps the bumps of the chip 110 .
[0070] The reinforcing sheet 140 is fixed to an edge region of the substrate 120 .
[0071] like Figure 3 As shown, the high modulus adhesive layer 150 is disposed between each side of the reinforcing sheet 140 and the substrate 120 , and the low modulus adhesive layer 160 is disposed between each corner of the reinforcing sheet 140 and the substrate 120 .
[0072] The chip packaging structure of the embodiment of the present disclosure improves stress release during the high-temperature curing process of the product by arranging a high-modulus adhesive layer between each side of the reinforcement sheet and the substrate, and arranging a low-modulus adhesive layer between each corner end of the reinforcement sheet and the substrate. The adhesive layers with different moduli are used to improve the stress release during the high-temperature curing process of the product, thereby improving product warping and ensuring that the bottom fill layer does not delaminate. The warping of the product can be reduced by about 100 μm, and the incidence of delamination of the bottom fill layer is reduced from 44% to 0%, thereby greatly improving the reliability of the chip packaging structure.
[0073] For example, Figure 5 As shown, a plurality of spaced bosses 141 are provided on one side of the reinforcing sheet 140 facing the substrate 120. The bosses 141 enable the adhesive layer between the reinforcing sheet 140 and the substrate 120 to have a predetermined thickness.
[0074] Exemplarily, the height of the boss 141 ranges from 55 μm to 65 μm. Preferably, in this embodiment, the height of the boss 141 is 60 μm.
[0075] In this embodiment, a plurality of bosses are provided on the side of the reinforcement sheet facing the substrate, which can not only ensure a sufficiently large reinforcement sheet mounting pressure to improve product warping, but also ensure that the high modulus adhesive layer and the low modulus adhesive layer have a preset thickness due to the action of the bosses, and prevent the problem of delamination of the reinforcement sheet glue, thereby improving the reliability of the chip packaging structure.
[0076] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the embodiments of the present disclosure, but the embodiments of the present disclosure are not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and essence of the embodiments of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the embodiments of the present disclosure.
Claims
1. A chip packaging method, characterized in that: include: Provide chips, substrates and reinforcement sheets separately; flip-chip mounting the chip on the substrate; forming an underfill layer between the chip and the substrate; forming a high modulus adhesive layer at an edge region of the substrate corresponding to a weak stress region of the reinforcing sheet; forming a low modulus adhesive layer at an edge region of the substrate corresponding to a strong stress region of the reinforcing sheet; The reinforcing sheet is fixed to the substrate through the high modulus adhesive layer and the low modulus adhesive layer respectively.
2. The chip packaging method according to claim 1, wherein: The reinforcing plate is provided with a plurality of spaced bosses on one side facing the base plate; The boss is used to ensure that the adhesive layer formed between the reinforcing sheet and the base plate has a preset thickness.
3. The chip packaging method according to claim 2, wherein: The height of the boss is in the range of 55 μm to 65 μm.
4. The chip packaging method according to any one of claims 1 to 3, characterized in that: The step of forming a high modulus adhesive layer at the edge area of the substrate and corresponding to the weak stress area of the reinforcement sheet comprises: High modulus glue is spot-coated on the edge area of the substrate and corresponding to the sides of the reinforcement sheet to form the high modulus glue layer.
5. The chip packaging method according to claim 4, characterized in that: The distance between the ends of two adjacent high modulus adhesive layers ranges from 8 mm to 10 mm.
6. The chip packaging method according to any one of claims 1 to 3, characterized in that: The step of forming a low modulus adhesive layer at an edge region of the substrate corresponding to a strong stress region of the reinforcing sheet comprises: Low modulus glue is spot-coated on the edge area of the substrate and at each corner end corresponding to the reinforcement sheet to form the low modulus glue layer.
7. The chip packaging method according to any one of claims 1 to 3, characterized in that: The step of fixing the reinforcing sheet to the substrate through the high modulus adhesive layer and the low modulus adhesive layer comprises: A preset pressure and a preset temperature are applied to the reinforcing sheet to solidify the high modulus adhesive layer and the low modulus adhesive layer, thereby fixing the reinforcing sheet to the substrate.
8. A chip packaging structure, characterized in that: Including chip, substrate, reinforcement sheet, bottom filler layer, high modulus glue layer and low modulus glue layer; The chip is flip-chip mounted on the substrate; The underfill layer is disposed between the substrate and the chip and wraps the bumps of the chip; The reinforcing sheet is fixed to the edge area of the substrate; The high modulus adhesive layer is disposed between each side edge of the reinforcing sheet and the substrate; The low modulus adhesive layer is arranged between each corner end of the reinforcing sheet and the base plate.
9. The chip packaging structure according to claim 8, wherein: The reinforcing plate is provided with a plurality of spaced bosses on one side facing the base plate; The boss can ensure that the adhesive layer between the reinforcing sheet and the base plate has a preset thickness.
10. The chip packaging structure according to claim 9, wherein: The height of the boss is in the range of 55 μm to 65 μm.