Packaging structure
By designing tapered silicone layer and primer layer space in wearable products, combined with selective spraying and laser polishing processes, the problem of insufficient bonding power between silicone and substrate is solved, and a high binding force and stability is achieved, reducing process risks and improving yields.
Patent Information
- Application Number
- CN202421550392.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-02
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2034-07-02
AI Technical Summary
In existing wearable products, the bonding force between silicone and substrate is insufficient, resulting in reduced reliability, and the reduction in the coverage area of the primer layer affects viscosity and increases process risks.
A package structure is designed in which the silicone layer and the primer layer form a tapered space in the cross-sectional view, which connect and penetrates the substrate, and combine to form a stepped shape to ensure stable connection between the electronic components and the pads, and avoid pad contamination through selective spraying and laser polishing processes.
It improves the binding force and stability of the packaging structure, reduces the difficulty of the process, reduces the risk of overflow, and improves the yield.
Smart Images
Figure CN223123893U_ABST
Abstract
Description
Technical Field
[0001] Embodiments of the present application relate to a packaging structure. Background Art
[0002] In recent years, with the rise of wearable devices, in addition to the increasing demand for various biometric detection and sensing devices, due to the rapid development of the Internet of Things, mobile communication devices, and micro sensors in wearable devices, all electronic products pursue being thin, light, short, and small. It can be seen that in the prior art, the size of electronic products needs to be thin, light, short, and small to meet market expectations. Therefore, integrating a biosensor into a single semiconductor system-in-package (SiP) to achieve this requirement, and adding that most current products are processed in irregular shapes, resulting in an increase in the manufacturing process technology and an increase in the risk of certain processes, such as the risk of overflow in spraying or underfilling. Therefore, it is necessary to develop a new product structure to reduce the risk of overflow.
[0003] Specifically, for the existing wearable product 10, such as Figure 1A and Figure 1B shown, to meet ergonomics, the wearable product 10 needs to use a flexible substrate (flexible board) 11 as the bottom board, and is supplemented with conductive silicone 13 as the material for encapsulating the die 14 (the die 14 is attached to the pad 11P through the adhesive layer 16) and making contact with the human body. The silicone 13 has a contact surface for contacting the human body, and the physiological signal is transmitted back to the detection element near the substrate 11 side through the signal receiving area A through this contact surface. The problem of such a wearable product 10 device in actual operation is that it is not easy to combine the silicone 13 with the substrate 11, and there is often a peeling phenomenon, resulting in a reduction in the reliability of the product 10. Therefore, a primer layer 12 is provided in the product to increase the bonding force between the silicone 13 and the substrate 11.
[0004] However, such a setting needs to prevent the primer of the primer layer 12 from contaminating above the pad 11P, otherwise it will be difficult to manufacture the lead 14w of the electronic component 14 and electrical problems are likely to occur. One current method is to set the primer layer 12 outside the pad area of the pad 11P, such as controlling the primer layer 12 by setting a solder mask 15, so as to balance the adhesion and avoid contamination at the pad 11P. However, as the customer's demand for the pad area of the pad 11P increases, the reduction in the area of the primer layer 12 will lead to the problem of poor adhesion. Summary of the Utility Model
[0005] To solve the above problems, the present application provides a packaging structure with better bonding force, stability, and higher yield.
[0006] Some embodiments of the present application provide a packaging structure, including: a flexible substrate; a primer layer disposed on the flexible substrate; and a silicone layer disposed on the primer layer; wherein, in a cross-sectional view, the silicone layer defines a first space, and in a first direction towards the flexible substrate, the first space has a tapered shape, and wherein the primer layer and the silicone layer jointly define at least a part of a second space, the second space has a tapered shape in the first direction, and the first space and the second space are connected and penetrate through the primer layer and the silicone layer.
[0007] In some embodiments, the second space and the first space form a stepped shape.
[0008] In some embodiments, the second space is located below the first space, and the second space is within the vertical projection range of the first space.
[0009] In some embodiments, the side walls of the first space and the second space are connected.
[0010] In some embodiments, the flexible substrate includes a recess.
[0011] In some embodiments, the recess is connected to the bottom of the second space.
[0012] In some embodiments, the packaging structure further includes: a pad disposed on the recess.
[0013] In some embodiments, the packaging structure further includes: an electronic component disposed above the pad and electrically connected to the pad.
[0014] In some embodiments, the top surface of the pad is higher than the bottom surface of the primer layer facing the flexible substrate.
[0015] In some embodiments, the electronic component is bonded to the pad by wire bonding.
[0016] In some embodiments, the primer layer is in contact with the side wall of the pad.
[0017] In some embodiments, the second space extends across the silicone layer and the primer layer, and further extends across a part of the flexible substrate.
[0018] In some embodiments, the step of the stepped shape exists in the silicone layer.
[0019] In some embodiments, the electronic component is spaced apart from the side wall of the primer layer.
[0020] In some embodiments, the electronic component is attached to the pad through an adhesive layer.
[0021] In some embodiments, a portion of the primer layer between adjacent ones of the pads forms a trapezoidal shape that is narrower at the top and wider at the bottom.
[0022] In some embodiments, the height of the first space in the first direction is greater than the height of the second space in the first direction.
[0023] Some other embodiments of the present application provide a packaging structure, including: a flexible substrate; a primer layer disposed on the flexible substrate; and a silicone layer disposed on the primer layer; wherein, the primer layer and the silicone layer have through holes extending through the primer layer and the silicone layer, and wherein, the side walls of the through holes have a stepped shape, and steps of the stepped shape are present in the silicone layer.
[0024] In some embodiments, the through hole has a first space above the step and a second space below the step, and the second space is within the vertical projection range of the first space.
[0025] In some embodiments, the flexible substrate includes a recess, wherein the recess is connected to the bottom of the second space.
[0026] The packaging structure provided by the present application has good bonding strength and stability and has a high yield. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] When read in conjunction with the accompanying drawings, various aspects of the present invention can be best understood from the following detailed description. It should be noted that, in accordance with standard practice in the industry, the various components are not drawn to scale. In fact, for the sake of clear discussion, the dimensions of the various components can be increased or decreased arbitrarily.
[0028] Figure 1A and Figure 1B shows a product of the prior art.
[0029] Figures 2A to 2C shows a packaging structure according to some embodiments of the present application.
[0030] Figures 3A to 3E shows a packaging structure according to some embodiments of the present application.
[0031] Figures 4 to 5 shows a manufacturing process of a packaging structure according to some embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0032] The following disclosure provides many different embodiments or examples for implementing different features of the present utility model. Specific examples of components and arrangements are described below to simplify the present utility model. Of course, these are merely examples and are not intended to limit the present utility model. In addition, when describing a numerical value or a numerical range with terms such as "substantially", "about", "substantially", "essentially", etc., unless otherwise specified, the term is intended to cover numerical values within ±10% of the described numerical value. For example, the term "about 5 nm" covers a size range from 4.5 nm to 5.5 nm.
[0033] This application provides a packaging structure with relatively good bonding force and stability. Specifically, referring to Figure 2A , this application provides a packaging structure 100, which includes a flexible substrate 101; a primer layer 102 disposed on the flexible substrate 101, and a silicone layer 103 disposed on the primer layer 102. Figure 2B Shows Figure 2A An enlarged view of a part of region B of Figure 2A And Figure 2B It can be seen that in the cross-sectional views shown in Figure 2A And Figure 2B , the silicone layer 103 defines a first space V1. In the first direction D towards the flexible substrate 101, the first space V1 has a tapered shape, that is, in the cross-sectional views shown in Figure 2A And Figure 2B , the width of the first space V1 between the opposite sidewalls V1s gradually decreases in the first direction D. In addition, the primer layer 102 and the silicone layer 103 jointly define at least a part of a second space V2. Similarly, the second space V2 has a tapered shape in the first direction D, that is, in the cross-sectional views shown in Figure 2A And Figure 2B , the width of the second space V2 between the opposite sidewalls V2s gradually decreases in the first direction D. In addition, as shown in Figures 2A to 2B , the first space V1 and the second space V2 are connected and form a through hole T. In some embodiments, the first space V1 and the second space V2 (through hole T) penetrate through the primer layer 102 and the silicone layer 103.
[0034] Furthermore, as shown in Figure 2A And Figure 2B , the second space V2 and the first space V1 form a stepped shape, and the step S of this stepped shape exists in the silicone layer 103. Further, the second space V2 is located below the first space V1, and the vertical projection Q2 of the second space V2 is within the range of the vertical projection Q1 of the first space V1. In other words, in Figure 2A And Figure 2BIn the cross-sectional view shown, the width of the second space V2 is less than the width of the first space V1, which is beneficial for the subsequent placement of the electronic component 104. Continuing to refer to Figure 2A and Figure 2B , the side wall V1s of the first space V1 and the side wall V2s of the second space V2 are connected. In Figure 2A and Figure 2B In the cross-sectional view shown, the side wall V1s of the first space V1 and the side wall V2s of the second space V2 are connected by a step S. In some other embodiments, the side wall V1s of the first space V1 is directly connected to the side wall V2s of the second space V2, that is, the side wall V1s of the first space V1 and the side wall V2s of the second space V2 are continuous (not shown). In some embodiments, the flexible substrate 101 includes a recess R, as shown in Figure 2A and Figure 2B . In a further embodiment, the recess R is connected to the bottom of the second space V2, that is, the second space V2 communicates with the recess R. In some other embodiments, the second space V2 extends across the silicone layer 103 and the primer layer 102, and may further extend across a part of the flexible substrate 101. Referring to Figure 2B , the height H1 of the first space V1 in the first direction D is greater than the height H2 of the second space V2 in the first direction D. It should be noted that the height H1 represents the distance between the top and the bottom of the first space V1 (i.e., the plane where the step S is located), and the height H2 represents the distance between the top of the second space V2 (i.e., the plane where the step S is located) and the bottom of the second space V2 (i.e., the top surface 101Pt of the pad 101P). In some specific embodiments, the height H1 is in the range of 300 - 400 μm, such as 375 μm, and the height H2 is in the range of 200 - 350 μm, such as 260 μm. In a further embodiment, the width w1 at the top of the first space V1 is in the range of 900 - 1100 μm, such as 1000 μm, and the width w2 at the bottom of the second space V2 is in the range of 400 - 500 μm, such as in the range of 400 - 480 μm, such as 450 μm. In some other embodiments, the second space V2 and the first space V1 may not form a stepped shape, that is, the through hole T formed by the first space V1 and the second space V2 has a continuous tapered shape in the first direction D.
[0035] Returning to refer to Figure 2A, the encapsulation structure 100 further includes a pad 101P disposed on the recess R. In addition, the encapsulation structure 200 further includes an electronic component 104 disposed on the pad 101P. The electronic component 104 is attached to the pad 101P through an adhesive layer 106 and is bonded to the pad 101P through wire bonding 104w. In some embodiments, the electronic component 104 is electrically connected to the pad 101P through the wire bonding 104w. In some other embodiments, the electronic component 104 is directly bonded to the pad 101P through a metal-to-metal bonding such as copper-to-copper and is directly electrically connected to the pad 101P. In some embodiments, the electronic component 104 is spaced apart from the sidewall 102s of the primer layer 102.
[0036] See Figure 2C , Figure 2C shows Figure 2A a partial cross-sectional view of the encapsulation structure 100 shown, from Figure 2C which it can be seen that the top surface 101Pt of the pad 101P is higher than the bottom surface 102d of the primer layer 101 facing the flexible substrate 101. In some embodiments, the top surface 101Pt of the pad 101P may be flush with the bottom surface 102d of the primer layer 101 facing the flexible substrate 101 (not shown). Continuing to refer to Figure 2C , the primer layer 102 contacts the sidewall 101Ps of the pad 101P. Continuing to see Figure 2A and Figure 2C , the portion 102m of the primer layer 102 between adjacent pads 101P forms a trapezoidal shape that is narrower at the top and wider at the bottom.
[0037] In the above embodiments, the flexible substrate 101 may be a flexible substrate commonly used in the art, such as a flexible printed circuit board. In some embodiments, the primer layer 102 includes a conductive material, such as a conductive material like copper, copper alloy, etc. In some embodiments, the silicone layer 103 may include the above conductive material and is a conductive silicone layer. The pad 101P includes a metal such as copper, and the electronic component 104 includes a chip such as an integrated circuit chip. The adhesive layer 106 includes but is not limited to an adhesive layer.
[0038] In addition, it should be noted that, as Figure 2A shown, the encapsulation structure 100 further includes an additional silicone layer 103' filled in the first space V1 and the second space V2. The additional silicone layer 103' and the silicone layer 103 that forms the first space V1 and the second space V2 may be conductive silicones of different materials or different metal ion contents, which is caused by etching the silicone layer 103 during the formation process. Therefore, there is a distinguishable interface between the silicone layer 103 and the additional silicone layer 103'.
[0039] Some other embodiments of the present application provide an encapsulation structure 100. SeeFigures 2A to 2C , the encapsulation structure 100 includes: a flexible substrate 101; a primer layer 102 disposed on the flexible substrate 101; and a silicone layer 103 disposed on the primer layer 102. Among them, the primer layer 102 and the silicone layer 103 have a through hole T extending through the primer layer 102 and the silicone layer 103, and among them, the side wall of the through hole T has a stepped shape, and the step S of the stepped shape exists in the silicone layer 103. In some embodiments, the through hole T has a first space V1 above the step S and a second space V2 below the step S, and the vertical projection Q2 of the second space V2 is within the vertical projection Q1 of the first space V1. In a further embodiment, the flexible substrate 101 includes a recess R, wherein the recess R is connected to the bottom of the second space V2.
[0040] Next, refer to Figures 3A to 3E , Figure 3A shows a top view of forming four through holes T1 to T4 of the encapsulation structure 100' corresponding to the encapsulation structure 100 using a laser, Figures 3B to 3E respectively show the scanning electron microscope images of the through holes T1 to T4 along the Figure 3A section C-C. It can be seen from Figure 3B that the through hole T1 formed by the laser has a first space V1 and a second space V2 disposed below the first space V1, and the first space V1 and the second space V2 form a stepped shape, and the step S of the stepped shape exists within the silicone layer 103. In the Figure 3B shown through hole T1, the height H1 of the first space V1 is 364 μm, the width w1 at the top of the first space V1 is 1070 μm, and the width w2 at the bottom of the second space V2 is 455 μm. Similarly, as Figure 3C shown, the first space V1 and the second space V2 of the through hole T2 formed by the laser form a stepped shape, and the step S of the stepped shape exists within the silicone layer 103. In the Figure 3C shown through hole T2, the height H1 of the first space V1 is 358 μm, the width w1 at the top of the first space V1 is 991 μm, and the width w2 at the bottom of the second space V2 is 459 μm. As Figure 3D shown, the first space V1 and the second space V2 of the through hole T3 formed by the laser form a stepped shape, and the step S of the stepped shape exists within the silicone layer 103. In the Figure 3D shown through hole T3, the height H1 of the first space V1 is 372 μm, the width w1 at the top of the first space V1 is 1050 μm, and the width w2 at the bottom of the second space V2 is 460 μm. After that, refer to Figure 3E, the first space V1 and the second space V2 of the through hole T4 formed by laser form a stepped shape, and the step S of this stepped shape exists within the silicone layer 103. In Figure 3E In the shown through hole T4, the height H1 of the first space V1 is 392 μm, the width w1 at the top of the first space V1 is 1100 μm, and the width w2 at the bottom of the second space V2 is 500 μm.
[0041] Refer back to Figure 2C , the present application can form the above-mentioned package structure 100 through related processes. Generally, selective spraying or selective underfilling processes can be carried out in a limited space. However, since it is required in the process that the primer layer 102 is formed without contaminating the related pads 101P, this can be achieved by changing the process flow to meet the above-mentioned process and improve the success rate and yield of the package structure 100. Specifically, the present application utilizes the concept similar to SMT (Surface Mount Technology), and by designing a mask plate such as a steel plate, the non-spraying area is covered with the mask plate, thereby reducing the process difficulty, which is beneficial to reducing costs and shortening the production time, and can improve the overall yield of the package structure 100. Or, the concept of etching can be utilized, and with the energy and characteristics of the laser, the primer layer 102 above the pad 101P is bombarded to peel off the primer layer 102, and then the surface of electronic components such as the pad 101P is cleaned by plasma or dry ice. In the present application, through the laser polishing function of the laser, an opening can be made above electronic components such as the pad 101P to form a through hole T, which is beneficial to reducing costs and shortening the production time, and can improve the overall yield.
[0042] It can be seen that the process provided by the present application can be superior to the existing processes, specifically as follows:
[0043] 1) Reduce costs and shorten the process time, and two processes of taping and de-taping can be reduced;
[0044] 2) Improve the yield. Since the primer layer 102m covers between the pads 101P, the problem of delamination in subsequent processes can be prevented; and
[0045] 3) The process difficulty is reduced because the present application can change the spin coating process from selective coating to full coating or to a printing process, so the overall process adjustment difficulty can be reduced.
[0046] Next, refer to Figure 4 process 400 and Figure 5 process 500 to introduce in detail the specific formation of the package structure 100.
[0047] Refer to Figure 4In the process 400, through the design of a mask plate (such as a steel plate), the mask plate produces a masking effect on the pad 101P. After that, the primer of the primer layer 102 can be evenly set on the flexible substrate 101 by coating 401, such as the method of blade coating or printing, and then, curing 402 commonly used in the art is carried out. It can be seen that the process 400 is suitable for large areas and has high efficiency, and can be coated between the pads 101P to increase adhesiveness.
[0048] In Figure 5 the process 500, the primer of the primer layer 102 and the silicone of the silicone layer 103 are first formed on the flexible substrate 101 by spin coating (full coating) 501 in sequence. After that, curing 502 is carried out by a method commonly used in the art, and then, laser polishing 503 is carried out on the primer layer 102 and the silicone layer 103 above the pad 101P through two laser methods, and the exposure of the pad 101P can also be achieved. Specifically, a larger first space V1 is formed in part of the silicone layer 103 by the first laser, and a smaller second space V2 is formed in other parts of the silicone layer 103 and the primer layer 102 by the second laser until the pad 101P is exposed. Among them, the vertical projection Q2 of the smaller second space V2 is within the vertical projection Q1 of the larger first space V1 (see Figure 2B ). In some embodiments, the second space V2 can further extend into the flexible substrate 101. It can be seen that through the first laser and the second laser, a through hole T with the first space V1 and the second space V2 is formed, and forming the larger first space V1 can facilitate the placement of the electronic component 104 later. After that, the exposed top surface 101Pt of the pad 101P is cleaned 504. After that, the electronic component 104 is placed on the pad 101P, and finally, the electronic component 104 is connected or a lead 104w is formed via wire bonding.
[0049] In the above processes, an additional silicone layer 103' needs to be formed finally to encapsulate the corresponding electronic component 104. In addition, the encapsulation structure 100 formed by the above processes uses the primer layer 102 to balance adhesiveness and effectively avoid the contamination of the pad 101P. Therefore, the encapsulation structure 100 provided by the present application has good bonding strength, good stability and a high yield.
[0050] Both the silicone layer 103 and the primer layer 102 in the encapsulation structure 100 provided by the present application have conductive functions, and their physiological signals can be processed in the order of silicone layer 103 → primer layer 102 → flexible substrate 101 → electronic component 104.
[0051] The features of several embodiments are outlined above so that those skilled in the art can better understand aspects of the present utility model. Those skilled in the art should understand that they can readily use the present utility model as a basis to design or modify other processes and structures for implementing the same purposes and / or achieving the same advantages as the embodiments illustrated herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present utility model, and that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of the present utility model.
Claims
1. An encapsulation structure, characterized in that, Comprising: A flexible substrate; A primer layer disposed on the flexible substrate; And A silicone layer disposed on the primer layer; Wherein, in a cross-sectional view, the silicone layer defines a first space, and in a first direction towards the flexible substrate, the first space has a tapered shape, and wherein the primer layer and the silicone layer jointly define at least a part of a second space, the second space has a tapered shape in the first direction, and the first space and the second space communicate with each other and penetrate through the primer layer and the silicone layer.
2. The encapsulation structure according to claim 1, characterized in that, The second space and the first space form a stepped shape.
3. The encapsulation structure according to claim 1, characterized in that, The second space is located below the first space, and the second space is within the vertical projection range of the first space.
4. The encapsulation structure according to claim 1, wherein The flexible substrate includes a recess, and the recess is connected to the bottom of the second space.
5. The encapsulation structure according to claim 4, wherein Further comprising: A pad disposed on the recess.
6. The encapsulation structure according to claim 5, wherein, Further comprising: An electronic component disposed above the pad and electrically connected to the pad.
7. The encapsulation structure according to claim 6, characterized in that The electronic component is bonded to the pad by wire bonding.
8. The encapsulation structure according to claim 6, wherein The second space extends across the silicone layer and the primer layer, and further extends across a part of the flexible substrate.
9. The encapsulation structure according to claim 6, wherein The electronic component is spaced apart from the side wall of the primer layer.
10. The encapsulation structure according to claim 1, characterized in that, The height of the first space in the first direction is greater than the height of the second space in the first direction.