A process, structure and material for packaging a fiber array module

Abstract

A FA fiber array module packaging process, structure and material capable of effectively reducing the multiple packaging bad phenomenon caused by UV glue curing shrinkage. It includes S1, forming a V-shaped groove on the quartz substrate; S2, placing the optical fiber in the V-shaped groove of the quartz substrate and adjusting its position; S3, uniformly placing the ABF dry film with a PET protective film layer on the quartz substrate; S4, sticking the ABF dry film on the upper surface of the quartz substrate through vacuum film sticking technology; S5, removing the PET protective film layer on the upper surface of the ABF dry film; S6, heating the entire FA fiber array module structure to ensure complete curing of the ABF dry film. The packaging structure and method can effectively avoid the multiple packaging bad phenomenon caused by UV glue curing shrinkage of the optical fiber during the packaging process of the FA fiber array module; while ensuring the smooth completion of the full packaging process of the FA optical module, it can effectively simplify the packaging process and significantly reduce the packaging cost.

Description

Technical Field

[0001] This invention relates to the field of FA (fiber optic array) optical module packaging technology, and in particular to a packaging process, structure and material for FA fiber optic array modules that can effectively reduce multiple packaging defects caused by UV adhesive curing shrinkage. Background Technology

[0002] The FA fiber array consists of a quartz V-groove substrate, bare optical fibers, a cover, and an MT ferrule as its core packaging structure. UV-cured epoxy resin is the only adhesive medium, which performs multiple functions such as fixing, sealing, and stress buffering. Its core functions are divided into three points: (1) Positioning and locking, filling the micron-level gap between the optical fiber and the V-groove and the cover plate, and constraining the position of the optical fiber after curing to ensure the spacing and height accuracy of the multi-channel optical fibers. (2) Optical path protection, isolating water vapor and dust, avoiding oxidation pollution of the bare fiber end face, and reducing end face scattering loss. (3) Mechanical reinforcement, improving the array's resistance to vibration and bending, and ensuring structural integrity under insertion, removal, high and low temperature conditions.

[0003] The standard usage method of UV curing epoxy adhesive in the entire process of FA packaging mainly includes: first, the quartz V-groove and bare fiber are cleaned and dried; the UV adhesive is quantitatively applied to the bottom of the V-groove and the edge of the cover plate using a micro-dispensing device; the bare fiber is accurately placed and aligned before pressing the cover plate; UV curing is carried out in stages, first with low power pre-curing to lock the fiber position, then with high power for complete curing, and finally the FA end face is ground to complete the processing. UV adhesive curing shrinkage is caused by the cross-linking reaction of resin molecules: the molecular spacing of liquid epoxy monomers is large, and after UV excitation, polymerization cross-linking occurs, and the molecules are tightly stacked, which is macroscopically manifested as volume shrinkage; insufficient filler, excessively fast curing rate, and excessive adhesive layer thickness will further amplify the shrinkage. Among them, UV adhesive curing shrinkage will cause multiple packaging defects, mainly including: (1) optical path coupling offset, shrinkage generates shear internal stress that pulls the fiber to undergo micron displacement, channel insertion loss increases, multi-channel loss uniformity deteriorates, and high-density 16 / 32 core FA temperature drift loss exceeds the standard. (2) Delamination and debonding at the interface: micro-gaps appear at the bonding interface between the adhesive layer and the bare fiber and quartz substrate. Moisture intrusion occurs under humid and hot conditions, resulting in pitting on the end face and increased scattering loss. (3) Decreased structural reliability: stress is concentrated on the brittle quartz substrate and bare fiber. Micro-cracks in the substrate and hidden cracks in the optical fiber are easily observed during temperature cycling tests. (4) Deterioration in batch consistency: fluctuations in adhesive application and curing light parameters cause differences in shrinkage. The dispersion of optical indicators in the same batch exceeds the standard, resulting in a decrease in packaging yield and increased rework costs.

[0004] Vacuum lamination technology is a core insulating dielectric molding process for advanced substrates, 2.5D / 3D packaging, and FC-BGA processes. Using Ajinomoto ABF dry film as the core material, it is an indispensable foundational process in high-end chip interconnect manufacturing. From a process yield perspective, traditional atmospheric pressure roll lamination easily traps air in micro-blind vias and deep trenches, resulting in voids and delamination defects. Vacuum chambers, however, can completely remove trapped gas within the chamber and micro-vias, eliminating interface bubbles at the source, significantly reducing scrap rates, and meeting the mass production needs of large-size, ultra-thin substrates. From a structural manufacturing perspective, vacuum lamination technology relies on vacuum pressure difference combined with uniform hot pressing. This process possesses excellent high aspect ratio micro-via filling capabilities, enabling high-density micro-line substrate molding. It supports the development of micro-pitch chip interconnects and high-order substrate wiring, providing technical support for the miniaturization and high-density of advanced packaging. From a device reliability perspective, vacuum lamination ensures a tight bond between the ABF film and the substrate / bump interface, resulting in higher interlayer adhesion, uniform and controllable film thickness, and no solvent residue, improving the device's resistance to moisture and heat and thermal shock. At the same time, the process has high cleanliness and low risk of contamination, which meets the high reliability manufacturing standards of high-end computing power, radio frequency and memory chips. It is a key technology for connecting chip wafers and substrates with fine wiring, and directly determines the performance, yield and industrialization capability of high-end packaging products.

[0005] In the field of chip packaging, the process flow of vacuum lamination technology mainly includes: (1) Pre-treatment loading. Peel off the outer PET protective film of ABF, position the carrier board / wafer to the vacuum chamber adsorption platform, automatically feed the dry film roll and complete the precise alignment, and keep the whole process clean and anti-static. (2) Vacuuming of the chamber. The sealed chamber is evacuated to a high vacuum of ≤0.5 Torr to completely remove the air trapped in the deep blind holes, trenches and bump gaps of the substrate and eliminate the root cause of interface bubbles. (3) Segmented hot pressing. The chamber is heated to 110–150℃ to reduce the viscosity of ABF resin. The flexible airbag is uniformly applied with a pressure of 3–5 MPa. First, low pressure pre-lamination is performed, and then high pressure is maintained for 60–90 s. The resin is driven by the pressure difference to flow into the microporous structure. (4) Leveling and pressure holding curing. Second constant temperature and pressure leveling is performed to eliminate film wrinkles and local glue shortages; low temperature pre-baking in a vacuum environment is used to avoid resin volatilization and the generation of pores. (5) Film cutting and unloading. Vacuum pressure cooling automatically trims excess dry film, peels off the support release film, and transfers to the subsequent laser drilling and curing process. The vacuum lamination technology isolates air throughout the entire process, reducing the bubble defect rate to below 0.1%; the airbag applies uniform pressure across the entire area, eliminating localized pressure damage from rollers; the dry film thickness consistency is superior to liquid coating, with no solvent contamination and controllable film thickness; it is suitable for ultra-thin substrates and large-size wafers, improving interlayer adhesion by over 30%, and is compatible with the mass production of FC-BGA and 2.5D / 3D advanced substrates. Furthermore, in the entire vacuum lamination process, vacuum pressure difference is the core driving force for filling. After vacuuming, the negative pressure inside the hole and the external airbag pressure create a bidirectional pressure difference, allowing low-viscosity ABF resin to wet and fill along the hole wall without obstruction, stably achieving 1:15–1:20 high aspect ratio micro-blind holes and void-free filling of deep trenches. Vacuum can prevent voids and insufficient adhesive at the bottom caused by air lock in the hole; flexible airbags adapt to uneven morphology, and pressure is fully transmitted at the bottom of deep holes, with complete coverage of the hole bottom and wall and no interface delamination; resin flows evenly, with no air bubbles left in the hole, and no open circuit defects in subsequent laser drilling and electroplating, which greatly improves the yield and interconnect reliability of high-end computing chip carrier boards.

[0006] Therefore, effectively reducing the volume shrinkage during the UV adhesive curing stage in the entire FA packaging process, thereby reducing multiple packaging defects caused by UV curing shrinkage, has always been a research hotspot in the field of FA optical module packaging technology. Vacuum lamination technology (using Ajinomoto ABF dry film as an example) can effectively fill micron-level gaps in advanced chip packaging structures (using Huatian Technology's e-SiFO technology as an example), eliminating voids caused by air locking within the holes, lack of adhesive at the bottom, and no interface delamination. Furthermore, after high-temperature baking, there are no classic application cases where the ABF film layer shrinks and forms voids. Therefore, applying vacuum lamination technology (equipped with Ajinomoto ABF dry film) to the FA optical module packaging process can effectively avoid multiple packaging defects caused by shrinkage during UV adhesive curing. Summary of the Invention

[0007] To address the aforementioned technical problems, the present invention aims to provide a packaging process, structure, and materials for FA fiber array modules that can effectively reduce multiple packaging defects caused by UV adhesive curing shrinkage. This packaging structure and method can effectively avoid multiple packaging defects caused by UV adhesive curing shrinkage during the FA fiber array module packaging process; while ensuring the smooth completion of the entire FA fiber array module packaging process, it can effectively simplify the packaging process and significantly reduce packaging costs.

[0008] To achieve the above technical objectives and effects, a FA fiber array module packaging process includes the following steps:

[0009] S1, forming a V-groove on the quartz substrate;

[0010] S2, Place the optical fiber in the V-groove of the quartz substrate and adjust its position;

[0011] S3, evenly place the dry film layer with PET protective film layer on the quartz substrate;

[0012] S4, dry film layer is bonded to the surface of quartz substrate by vacuum lamination technology;

[0013] S5, Remove the PET protective film layer on the upper surface of the dry film layer;

[0014] S6 heats the entire FA fiber array module structure to ensure the dry film layer is completely cured; after the dry film layer is completely cured, it acts as an insulating protective layer (physical protection, chemical protection, water and oxygen isolation, etc.) for the FA fiber array module, and no additional glass cover is needed.

[0015] The dry film layer mentioned in step S3 is a type of dry film material such as epoxy resin, polyimide, or ABF dry film.

[0016] Preferably, the dry film layer is an ABF dry film.

[0017] According to another aspect of the present invention, a FA fiber array module packaging structure that effectively reduces multiple packaging defects caused by UV curing shrinkage is obtained by the above packaging process, comprising: a quartz substrate, a dry film layer, and a plurality of V-grooves provided on the upper surface of the quartz substrate, wherein the optical fiber is placed in the V-grooves of the quartz substrate.

[0018] There is a gap between the optical fiber and the V-groove of the quartz substrate;

[0019] An organic dry film layer is formed on the quartz substrate and in the gap between the optical fiber and the V-groove of the quartz substrate using vacuum lamination technology, and the dry film layer is baked at high temperature. After the dry film layer is cured, it serves as the insulating protective layer (physical protection, chemical protection, water and oxygen isolation, etc.) of the FA fiber array module, and no additional glass cover plate is required.

[0020] According to another aspect of the present invention, the present invention provides a packaging material for FA fiber array modules, comprising a dry film layer. The dry film layer, through vacuum lamination technology (taking Ajinomoto ABF dry film as an example), effectively fills the micron-level gaps in the FA fiber array module packaging structure, eliminating voids caused by air locking within the holes, lack of adhesive at the bottom, and interfacial delamination. Furthermore, after high-temperature baking, the dry film layer does not exhibit voids due to shrinkage, thereby effectively reducing the occurrence of multiple packaging defects during the FA fiber array module packaging process. Simultaneously, compared to UV-curable adhesives, ABF dry film is cheaper and has a simpler application process, effectively simplifying the FA packaging process and reducing production costs.

[0021] The beneficial effects of this invention are mainly as follows: (1) By using Ajinomoto ABF dry film to replace UV curing adhesive, and based on vacuum film bonding technology, the thermal curing method can effectively avoid the problem of voids caused by volume shrinkage after ABF dry film curing, thereby effectively reducing the occurrence of multiple encapsulation defects in the FA fiber array module packaging process; (2) The Ajinomoto ABF dry film used is a non-photosensitive material. Compared with the UV curing adhesive process (UV light irradiation curing), ABF dry film only needs to be heated and baked to complete the complete curing and molding; ABF dry film is cheaper and the packaging process is simpler, which can significantly reduce the packaging cost; (3) After curing, ABF dry film can directly serve as the insulating protective layer (physical protection, chemical protection, water and oxygen isolation, etc.) of FA fiber array module, without the need for additional glass cover protection, which can effectively simplify the FA optical module packaging process and reduce production costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of forming a V-groove on a quartz substrate according to the present invention.

[0023] Figure 2 This is a schematic diagram of a structure in which an optical fiber is placed in a V-groove on a quartz substrate.

[0024] Figure 3 To remove the lower PET protective film, the ABF dry film is evenly placed... Figure 2 A structural diagram.

[0025] Figure 4 This is a schematic diagram of a structure for bonding ABF dry film with a PET protective film layer on the upper surface to a quartz substrate using vacuum lamination technology.

[0026] Figure 5 To uncover Figure 4 A schematic diagram of the PET protective film layer on the upper surface of the ABF dry film in the structure. Detailed Implementation

[0027] The invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] (1) A V-groove is formed on a quartz substrate to obtain the following: Figure 1 The structure shown is as follows. 10 is a quartz substrate, and 101 is a V-groove structure.

[0029] (2) Place the optical fiber in the V-groove of the quartz substrate to obtain the following result: Figure 2 The structure is shown. 11 represents the optical fiber. A gap exists between the optical fiber and the quartz V-groove. During this process, the position of the optical fiber within the quartz V-groove must be continuously adjusted to ensure optimal optical communication performance.

[0030] (3) Place the ABF dry film with the bottom PET protective film removed evenly on the ground. Figure 2 The structure shown yields the following result: Figure 3 The structure is shown. 12 is the ABF dry film layer, and 13 is the PET protective film layer on the upper surface of the ABF dry film.

[0031] (4) Using vacuum lamination technology, ABF dry film with a PET protective film layer on its upper surface is bonded to the upper surface of a quartz substrate (with an optical fiber inside the V-groove), resulting in the following: Figure 4 The structure shown is such that during the lamination process, the V-grooves on the quartz substrate are completely filled by the ABF dry film.

[0032] (5) Remove Figure 4 The PET protective film layer on the upper surface of the ABF dry film in the structure results in the following: Figure 5 The structure shown.

[0033] (6) Heat the entire FA fiber array module structure, so that... Figure 5 The ABF dry film layer in the structure shown is completely cured to ensure adhesion between the ABF dry film and the quartz substrate, while further fixing the position of the optical fiber to restrict its movement.

[0034] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A packaging process, structure, and materials for a fiber optic array module, characterized in that, Includes the following steps: S1, forming a V-groove on the quartz substrate; S2, Place the optical fiber in the V-groove of the quartz substrate and adjust its position; S3, evenly place the dry film layer with PET protective film layer on the quartz substrate; S4, dry film layer is bonded to the surface of quartz substrate by vacuum lamination technology; S5, Remove the PET protective film layer on the upper surface of the dry film layer; S6 heats the entire FA fiber array module structure to ensure the dry film layer is fully cured; after the dry film layer is fully cured, it acts as an insulating protective layer for the FA fiber array module, eliminating the need for an additional glass cover.

2. The packaging process according to claim 1, characterized in that: The dry film layer mentioned in step S3 is one of epoxy resin, polyimide, or Ajinomoto ABF dry film.

3. The packaging process according to claim 2, characterized in that: The dry film layer mentioned in step S3 is an ABF dry film.

4. A FA fiber array module packaging structure obtained by the packaging process according to any one of claims 1 to 3, characterized in that: include: Quartz substrate, dry film layer, several V-grooves are set on the upper surface of the quartz substrate, and optical fibers are placed in the V-grooves of the quartz substrate; There is a gap between the optical fiber and the V-groove of the quartz substrate; An organic dry film layer is formed on the quartz substrate and in the gap between the fiber and the V-groove of the quartz substrate using vacuum lamination technology, and the dry film layer is baked at high temperature. After the dry film layer is cured, it serves as the insulating protective layer of the FA fiber array module, eliminating the need for an additional glass cover plate.

5. A packaging material for a fiber optic array module, characterized in that, Applied to claim 1 or 4, it includes a dry film layer, wherein the dry film layer effectively fills the micron-level gaps in the FA fiber array module packaging structure through vacuum lamination technology, eliminating voids caused by air locking in the holes, lack of adhesive at the bottom, and no interface delamination. After high-temperature baking, the dry film layer will not have voids due to shrinkage, thereby effectively reducing the occurrence of multiple packaging defects during the FA fiber array module packaging process.

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