Manufacturing method of packaging structure for improving reliability of vehicle-mounted chip and product thereof

Abstract

The invention discloses a manufacturing method of a packaging structure for improving the reliability of a vehicle-mounted chip and a product thereof. The method comprises the following steps: completing bonding of a substrate and the vehicle-mounted chip; thinning the vehicle-mounted chip and etching a silicon through hole; carrying out oxidation pretreatment on the vehicle-mounted chip; carrying out oxidation treatment on the vehicle-mounted chip; preparing a dielectric layer on the surface of the vehicle-mounted chip; preparing an RDL rewiring layer on the surface of the vehicle-mounted chip, connecting the RDL rewiring layer with a PAD of the vehicle-mounted chip, covering the surface of the vehicle-mounted chip with a solder mask layer, and forming a signal export structure; and cutting the product obtained in the previous step into single dies. The method solves the problems of warping and electric leakage of a conventional product, solves the problems of too thin glue at the corner of a solder mask groove and the like, reduces the stress of the product, prevents the PAD from being pulled up by the stress, remarkably improves the reliability, saves the step of an organic passivation layer, reduces the whole process, greatly reduces the packaging cost, remarkably improves the productivity, and improves the production efficiency. The method is suitable for industrial popularization and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor packaging, and particularly relates to a manufacturing method and a product of a packaging structure for improving the reliability of in-vehicle chips. Background Art

[0002] With the continuous development of semiconductor product packaging technology, the industry's application requirements for products are also getting higher and higher. The structure of products is becoming increasingly complex, leading to a series of technical problems. Among them, improving the reliability of in-vehicle products is a difficult problem in the industry. In the in-vehicle imaging chip industry, a double-layer insulation layer structure of a low dielectric constant material and an organic passivation layer is usually used to improve the reliability of electrification, but this also brings problems such as chips caused by product warping.

[0003] For the organic passivation layer used in the TSV industry process flow, due to the structural problems of the product itself, it often leads to uneven glue thickness in the hole and groove, such as too thick at the inner corner of the groove and too thin at the inner wall of the hole. In this way, the product has both the risk of leakage and the warping caused by too thick glue thickness of the product and the reliability delamination caused by too thin at the corner of the solder mask layer groove. At the same time, the use of the organic passivation layer also greatly increases the packaging material cost. Summary of the Invention

[0004] In order to solve the technical problems of reliability failure caused by product warping and leakage in the prior art, the purpose of the present invention is to provide a manufacturing method and a product of a packaging structure for improving the reliability of in-vehicle chips.

[0005] To achieve the above purpose and reach the above technical effects, the technical solution adopted by the present invention is as follows:

[0006] A manufacturing method of a packaging structure for improving the reliability of in-vehicle chips, comprising the following steps:

[0007] Step 1: Complete the bonding of the substrate and the in-vehicle chip;

[0008] Step 2: Complete the thinning of the in-vehicle chip and the etching of the through-silicon via;

[0009] Step 3: Perform pre-oxidation treatment on the in-vehicle chip;

[0010] Step 4: Perform oxidation treatment on the in-vehicle chip;

[0011] Step 5: Prepare a dielectric layer on the surface of the in-vehicle chip;

[0012] Step 6: Prepare an RDL (Redistribution Layer) on the surface of the in-vehicle chip and connect it to the PAD of the in-vehicle chip, then cover the solder mask layer on the surface of the in-vehicle chip and form a signal output structure;

[0013] Step 7: Cut the product obtained in Step 6 into single dies.

[0014] Further, in Step 1, the steps of completing the bonding between the substrate and the in-vehicle chip include:

[0015] Coat a negative photoresist on the surface of the substrate, form a cofferdam through a photolithography process, apply a bonding adhesive on the cofferdam, and mount the in-vehicle chip on the substrate through the bonding adhesive.

[0016] Further, in Step 3, the steps of performing pre-oxidation treatment on the in-vehicle chip include:

[0017] Successively prepare a barrier layer and a positive photoresist on the surface of the in-vehicle chip. Through the photolithography process, only the positive photoresist is retained in the photosensitive area of the in-vehicle chip to protect the barrier layer under the photosensitive area from being oxidized by the subsequent oxidation process.

[0018] Further, the material of the barrier layer includes copper or aluminum.

[0019] Further, in Step 4, the steps of performing oxidation treatment on the in-vehicle chip include:

[0020] On the surface of the in-vehicle chip, the barrier layer not covered by the positive photoresist is made into an oxide layer through an anodic oxidation process. Then, the positive photoresist is removed from the photosensitive area, exposing the barrier layer above the photosensitive area.

[0021] Further, the material of the oxide layer includes copper oxide or aluminum oxide.

[0022] Further, in Step 5, the material of the dielectric layer includes silicon dioxide, silicon nitride, or aluminum oxide.

[0023] Further, in Step 6, first open the bottom of the through-silicon via to expose the PAD of the in-vehicle chip. Then, prepare an RDL (Redistribution Layer) on the surface of the in-vehicle chip and connect it to the PAD. Next, cover the surface of the in-vehicle chip with a solder mask layer, open the surface pads, and form a signal output structure.

[0024] Further, the solder mask layer is a negative photoresist, the material is polyisoprene, and the thickness is 10 - 20 μm.

[0025] The present invention also discloses a packaging structure for improving the reliability of in-vehicle chips, which is manufactured by using the manufacturing method of a packaging structure for improving the reliability of in-vehicle chips as described above. The packaging structure includes a substrate, an in-vehicle chip is mounted on the substrate. A barrier layer is provided in the photosensitive area of the in-vehicle chip, an oxide layer is provided in the non-photosensitive area of the in-vehicle chip. A dielectric layer, an RDL redistribution layer, and a solder mask layer are successively provided on the surface of the in-vehicle chip from the inside to the outside. The RDL redistribution layer is connected to the PAD of the in-vehicle chip, and a signal output structure is connected to the RDL redistribution layer.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] The present invention discloses a manufacturing method and a product of a packaging structure for improving the reliability of in-vehicle chips. The manufacturing method requires first completing the chip bonding, thinning, and through-silicon via processes, then preparing a barrier layer and a positive photoresist on the chip surface. After the lithography process, the positive photoresist is retained in the photosensitive area. The barrier layer is used to absorb and block infrared light. The remaining exposed part of the barrier layer forms an oxide layer through an anodic oxidation process, and then the positive photoresist is removed to expose the barrier layer in the photosensitive area. Then, a dielectric layer is prepared on the chip surface. Finally, through the RDL, solder mask, ball mounting, and final cutting processes, the TSV packaging is completed. By adopting the above process steps, the problems of product warping and leakage are solved, the problem of too thin adhesive thickness at the corners of the solder mask grooves is solved, the product stress is reduced, and the PAD will not be pulled up by the stress, significantly improving the reliability. At the same time, the step of the organic passivation layer is omitted, the whole process is reduced, the packaging cost is greatly reduced, and the production capacity is significantly improved, which is suitable for industrial promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figures 1-3 They are respectively the structural schematic diagrams of Step 1 of the present invention;

[0029] Figure 4 It is the structural schematic diagram of Step 2 of the present invention;

[0030] Figures 5-6 They are respectively the structural schematic diagrams of Step 3 of the present invention;

[0031] Figure 7 It is the structural schematic diagram of Step 4 of the present invention;

[0032] Figure 8 It is the structural schematic diagram of Step 5 of the present invention;

[0033] Figures 9-11 They are respectively the structural schematic diagrams of Step 6 of the present invention;

[0034] Figure 12 It is the structural schematic diagram of Step 7 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0035] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making the protection scope of the present invention more clearly defined.

[0036] The following gives a brief overview of one or more aspects to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all contemplated aspects, and is neither intended to identify key or decisive elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description to follow.

[0037] As Figures 1-12 shown, the present invention discloses a manufacturing method of a packaging structure for improving the reliability of in-vehicle chips, including the following steps:

[0038] Step 1: Coat a layer of negative photoresist on the surface of the glass 10, form a dam 11 through a photolithography process, apply a layer of bonding glue 12 on the dam 11, and then complete the bonding with the in-vehicle chip 13, as Figures 1-3 shown;

[0039] Step 2: After bonding the glass 10 and the in-vehicle chip 13, through processes such as grinding, photolithography, and dry etching, complete the thinning of the in-vehicle chip and the etching of the through-silicon vias, as Figure 4 shown;

[0040] Step 3: Prepare a barrier layer 14 on the surface of the in-vehicle chip 13 for absorbing and blocking infrared rays in the photosensitive area. The material of the barrier layer 14 is not limited to metals such as aluminum and copper, and apply a layer of positive photoresist 15. Through the photolithography process, the positive photoresist 15 remains in the photosensitive area of the in-vehicle chip 13 to protect the barrier layer 14 under the photosensitive area from being oxidized by subsequent oxidation processes, as Figures 5-6 shown;

[0041] Step 4: On the surface of the in-vehicle chip 13, subject the barrier layer 14 not covered by the positive photoresist 15 to an anodization process (according to different electrolytes, the anodization process can be divided into oxidation processes such as sulfuric acid method, oxalic acid method, chromic acid method, and mixed acid method) to prepare an oxide layer 16 for insulating the sidewalls of the holes and grooves. The material is not limited to metal oxides such as aluminum oxide and copper oxide. After degluing, remove the positive photoresist 15 from the photosensitive area to expose the barrier layer 14 above the photosensitive area, as Figure 7 shown;

[0042] Step 5: Prepare a dielectric layer 17 on the surface of the in-vehicle chip 13, which can be prepared by methods such as chemical vapor deposition and atomic layer deposition. The material is not limited to oxides or nitrides such as silicon dioxide, silicon nitride, and aluminum oxide, as Figure 8 shown;

[0043] Step 6: Open the bottom of the through-silicon via to expose the PAD of the in-vehicle chip 13, prepare the RDL redistribution layer 18 through a series of processes and connect it to the PAD, cover the in-vehicle chip 13 with a solder mask layer 19. The method is not limited to spin coating, spraying glue, printing, etc. The solder mask layer 19 is a negative photoresist with a material of polyisoprene and a thickness of 10 - 20 μm. After exposure and development, open the surface pads to complete the ball mounting process to form a signal output structure 20, as Figures 9-11 shown;

[0044] Step 7: Cut the in-vehicle chip 13 into single dies, and the final product is asFigure 12 The structure shown

[0045] The present invention also discloses a packaging structure for improving the reliability of in-vehicle chips, which is manufactured by using the manufacturing method of a packaging structure for improving the reliability of in-vehicle chips as described above. The packaging structure includes a substrate 10, on which an in-vehicle chip 13 is attached. A barrier layer 14 is provided in the photosensitive area of the in-vehicle chip 13, and an oxide layer 16 is provided in the non-photosensitive area of the in-vehicle chip 13. A dielectric layer 17, an RDL (Redistribution Layer) 18, and a solder mask layer 19 are sequentially provided on the surface of the in-vehicle chip 13 from the inside to the outside. The RDL 18 is connected to the PAD of the in-vehicle chip 13, and a signal output structure 20 is connected to the RDL 18.

[0046] Embodiment 1

[0047] As Figures 1-12 shown, a manufacturing method of a packaging structure for improving the reliability of in-vehicle chips includes the following steps:

[0048] Step 1: Coat a layer of negative photoresist on the surface of the glass 10, form a dam 11 through a photolithography process, coat a layer of bonding glue 12 on the dam 11, and then complete the bonding with the in-vehicle chip 13, as Figures 1-3 shown;

[0049] Step 2: After bonding the glass 10 and the in-vehicle chip 13, through processes such as grinding, photolithography, and dry etching, complete the thinning of the in-vehicle chip and the etching of the through-silicon via, as Figure 4 shown;

[0050] Step 3: Prepare a barrier layer 14 on the surface of the in-vehicle chip 13 for absorbing and blocking infrared rays in the photosensitive area. The material of the barrier layer 14 is aluminum, and coat a layer of positive photoresist 15. Through a photolithography process, the positive photoresist 15 remains in the photosensitive area of the in-vehicle chip 13 to protect the barrier layer 14 under the photosensitive area from being oxidized by subsequent oxidation processes, as Figures 5-6 shown;

[0051] Step 4: Anodize the barrier layer 14 on the surface of the in-vehicle chip 13 that is not covered by the positive photoresist 15 (according to different electrolytes, the anodizing process can be divided into oxidation processes such as sulfuric acid method, oxalic acid method, chromic acid method, and mixed acid method) to prepare an oxide layer 16 for insulating the sidewalls of the holes and grooves. The material is aluminum oxide. After degluing, remove the positive photoresist 15 from the photosensitive area to expose the barrier layer 14 above the photosensitive area, as Figure 7 shown;

[0052] Step 5: Prepare a dielectric layer 17 on the surface of the in-vehicle chip 13, which can be prepared by methods such as chemical vapor deposition and atomic layer deposition. The material is silicon dioxide, as Figure 8 shown;

[0053] Step Six: Open the bottom of the TSV to expose the PAD of the in-vehicle chip 13. After a series of processes, prepare the RDL (Redistribution Layer) 18 and connect it to the PAD. Cover the surface of the in-vehicle chip 13 with the solder mask layer 19. The method is not limited to spin coating, spray coating, printing, etc. The solder mask layer 19 is a negative photoresist made of polyisoprene with a thickness of 10 μm. After exposure and development, open the surface pads and complete the ball mounting process to form the signal output structure 20, where the signal output structure 20 is a solder ball, as Figures 9-11 shown;

[0054] Step Seven: Cut the in-vehicle chip 13 into single dies, and the final product is as Figure 12 shown in the structure.

[0055] A packaging structure for improving the reliability of an in-vehicle chip is manufactured by using the manufacturing method of a packaging structure for improving the reliability of an in-vehicle chip as described above. The packaging structure includes a substrate 10, an in-vehicle chip 13 is mounted on the substrate 10. A barrier layer 14 is provided in the photosensitive area of the in-vehicle chip 13, and an oxide layer 16 is provided in the non-photosensitive area of the in-vehicle chip 13. A dielectric layer 17, an RDL (Redistribution Layer) 18, and a solder mask layer 19 are sequentially provided on the surface of the in-vehicle chip 13 from the inside to the outside. The RDL 18 is connected to the PAD of the in-vehicle chip 13, and a solder ball is connected to the RDL 18.

[0056] For the parts or structures not specifically described in the present invention, existing technologies or existing products can be adopted, and no further elaboration will be made here.

[0057] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A method for manufacturing a packaging structure for improving the reliability of an on-board chip, characterized in that: The following steps are involved: Step 1: Complete the bonding between the substrate and the vehicle chip; Step 2: Complete the thinning of the on-board chip and the etching of through-silicon vias; Step 3: Pre-oxidation treatment of the on-board chip; Step 4: Oxidation treatment of the vehicle-mounted chip; Step 5: preparing a dielectric layer on the surface of the vehicle chip; Step 6: Prepare an RDL redistribution layer on the surface of the vehicle chip and connect it to the PAD of the vehicle chip, then cover the surface of the vehicle chip with a solder mask layer to form a signal export structure; Step 7: Cut the product obtained in step 6 into single dies.

2. The method for manufacturing a packaging structure for improving the reliability of an on-board chip according to claim 1, characterized in that: In step 1, the steps of completing the bonding between the substrate and the vehicle-mounted chip include: Negative photoresist is coated on the surface of the substrate, a cofferdam is formed through a photolithography process, bonding glue is coated on the cofferdam, and the vehicle-mounted chip is mounted on the substrate through the bonding glue.

3. The method for manufacturing a packaging structure for improving the reliability of an on-board chip according to claim 1, characterized in that: In step 3, the steps of pre-oxidation treatment of the vehicle-mounted chip include: A barrier layer and a positive photoresist are prepared in sequence on the surface of the vehicle-mounted chip. After a photolithography process, the positive photoresist is retained only in the photosensitive area of ​​the vehicle-mounted chip to protect the barrier layer under the photosensitive area from being oxidized by a subsequent oxidation process.

4. The method for manufacturing a packaging structure for improving the reliability of an on-board chip according to claim 3, characterized in that: The material of the barrier layer includes copper or aluminum.

5. The method for manufacturing a packaging structure for improving the reliability of an on-board chip according to claim 3, characterized in that: In step 4, the step of oxidizing the vehicle-mounted chip includes: The barrier layer on the surface of the vehicle-mounted chip that is not covered with the positive photoresist is subjected to an anodizing process to form an oxide layer, and then the positive photoresist is removed from the photosensitive area to expose the barrier layer above the photosensitive area.

6. The method for manufacturing a packaging structure for improving the reliability of an on-board chip according to claim 5, characterized in that: The material of the oxide layer includes copper oxide or aluminum oxide.

7. The method for manufacturing a packaging structure for improving the reliability of an on-board chip according to claim 1, characterized in that: In step five, the material of the dielectric layer includes silicon dioxide, silicon nitride or aluminum oxide.

8. The method for manufacturing a packaging structure for improving the reliability of an on-board chip according to claim 1, characterized in that: In step six, the bottom of the through silicon via is first opened to expose the PAD of the vehicle-mounted chip, and then the RDL redistribution layer is prepared on the surface of the vehicle-mounted chip and connected to the PAD, and then the solder mask layer is covered on the surface of the vehicle-mounted chip, the surface pad is opened and a signal export structure is formed.

9. The method for manufacturing a packaging structure for improving the reliability of an on-board chip according to claim 1, characterized in that: The solder resist layer is a negative photoresist made of polyisoprene and has a thickness of 10-20 μm.

10. A packaging structure for improving the reliability of an on-board chip, characterized in that: The packaging structure is manufactured by the manufacturing method of a packaging structure for improving the reliability of an on-board chip as described in any one of claims 1 to 9, wherein the packaging structure includes a substrate, a vehicle-mounted chip is mounted on the substrate, a barrier layer is provided in the photosensitive area of ​​the vehicle-mounted chip, an oxide layer is provided in the non-photosensitive area of ​​the vehicle-mounted chip, a dielectric layer, an RDL redistribution layer, and a solder resist layer are provided on the surface of the vehicle-mounted chip from the inside to the outside, the RDL redistribution layer is connected to the PAD of the vehicle-mounted chip, and a signal export structure is connected to the RDL redistribution layer.

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