A new ACF process hot press head structure

Abstract

The utility model discloses a novel ACF process hot press pressure head structure, this novel ACF process hot press pressure head structure. The whole process because of the conductive particle 10um, the requirement particle flat ratio after pressing is 14 to 18um, need the high flatness of pressing surface, at present because of the height difference of PCB & FPC ink layer and copper layer, influence hot press head and the flatness of pressing surface. Design pressure head to avoid this position, form hot press head by all plane changes to hollow in the middle, inside width and PCB & FPC inside ink width tolerance one side 0.2mm. Thus avoid, ink layer interference hot press head pressing. The height of hollow in the middle is reserved, in order to let FPC in the hot pressing process and the influence product overall back flatness, hollow depth 0.170mm. Form slight pressure in the middle, prevent FPC pressing process from warping. Prevent ACF overflow glue to the FPC periphery and form convex glue line, hollow step outside hot press head, avoid the overflow glue of glue and form convex, realized the purpose that hot press head pressing effect is better.

Description

Technical Field

[0001] This utility model belongs to the field of hot press head structure, specifically, it relates to a novel hot press head structure for ACF process. Background Technology

[0002] Currently, the most widely used ACF (Antenna Fold) bonding process in the camera module industry uses a flat-head hot press head. Through the application of ACF conductive adhesive, the module's FPC (Flexible Printed Circuit) is bonded to the PCB (Printed Circuit Board) after heating, pressing, and curing. Conductive particles within the adhesive connect the FPC and PCB circuitry, enabling signal transmission between the phone's motherboard and the camera module.

[0003] The existing hot press head, being a flat-headed design, causes ink interference in PCB and FPC, resulting in an uneven bonding surface. This affects the uneven crushing of 10µm conductive particles within the adhesive, reducing its conductivity reliability. Adhesive overflow occurs during the pressing process, causing adhesive protrusions around the PCB, affecting the flatness of the camera module's bottom. This leads to optical axis misalignment in the assembled camera, impacting subsequent product quality and resulting in excessive defective products. This not only affects the quality of manufactured products but also increases material waste and reduces yield. Furthermore, rework occurs during assembly, significantly impacting production efficiency.

[0004] In view of this, this utility model is proposed. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a new type of ACF process hot press head structure, which solves the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by this utility model is as follows:

[0007] A novel ACF (Anti-Fluorescence) process hot press head structure includes: a hot press head, a central groove at the front center of the hot press head, a second right groove at the front right side of the hot press head, a second left groove at the front left side of the hot press head, a first right sliding groove at the front right side of the central groove, and a first left sliding groove at the front left side of the central groove. Through the coordinated use of the hot press head, central groove, first right sliding groove, second right groove, first left sliding groove, and second left groove, this design achieves a stronger pressing effect; flatness is controlled within 0.12mm, particle crushing effect is improved, and electrical function failure has been reduced from 2% to 0.02%. By using the hot press head, the central groove, the first right slide groove, the second right groove, the first left slide groove, and the second left groove in combination, the number of processes is reduced. In the early stage, the appearance size of the overflow module exceeded the standard and required a glue scraping process. After the glue overflow was improved, there was no need for glue scraping. This makes it more versatile. All camera ACF processes can be used according to this design, and the design specifications are standardized.

[0008] Preferably, the hot press head is fixedly connected to the rear side of the hot press head, and the overall height of the hot press head is the same as the height of the hot press head.

[0009] Preferably, the height of the central groove is the same as the height of the hot press head, the length of the central groove is 5.7 mm, and the width of the central groove is 0.17 mm.

[0010] Preferably, the height of the second right groove and the second left groove is the same as the height of the hot press head, the length of the second right groove and the second left groove is 0.2mm, and the width of the second right groove and the second left groove is 0.05mm.

[0011] Preferably, the heights of the first right slide groove and the first left slide groove are the same as the height of the hot press head.

[0012] Preferably, the first right slide groove and the first left slide groove are rounded corners formed on the left and right sides of the front end of the central groove, and the radius of the rounded corners is 0.05mm.

[0013] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all of the following advantages at the same time:

[0014] 1. This new type of ACF process hot press head structure, through the coordinated use of the hot press head, central groove, first right slide groove, second right groove, first left slide groove, and second left groove, has a stronger hot press head pressing effect; the flatness is controlled within 0.12mm, the particle crushing effect is improved, and the electrical function failure rate has been reduced from 2% to 0.02%.

[0015] 2. This new type of ACF process hot press head structure, through the coordinated use of the hot press head, central groove, first right slide groove, second right groove, first left slide groove, and second left groove, reduces the number of processes. Due to the problem of excessive glue overflow in the early stage, the appearance size of the module required a glue scraping process. After the glue overflow is improved, there is no need for glue scraping. It makes the versatility stronger. All camera ACF processes can be used according to this design, and the design specifications are standardized.

[0016] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. Attached Figure Description

[0017] The accompanying drawings described below are merely some embodiments. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0018] In the picture:

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is an enlarged view of section A of the structure of this utility model;

[0021] Figure 3 This is a schematic diagram of the three-dimensional structure of the hot press head.

[0022] The attached diagram lists the components represented by each number as follows:

[0023] 1. Hot press head; 2. Central groove; 3. First right slide groove; 4. Second right groove; 5. First left slide groove; 6. Second left groove; 7. Hot press head assembly.

[0024] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings.

[0026] Please see Figure 1-3 As shown, this embodiment provides a novel ACF process hot press head structure, including a hot press head 1. A central groove 2 is provided in the middle of the front end of the hot press head 1. A second right groove 4 is provided on the right side of the front end of the hot press head 1. A second left groove 6 is provided on the left side of the front end of the hot press head 1. A first right sliding groove 3 is provided on the right side of the front end of the central groove 2. A first left sliding groove 5 is provided on the left side of the front end of the central groove 2.

[0027] The hot press head 7 is fixedly connected to the rear side of the hot press head 1, and the height of the hot press head 7 is the same as the height of the hot press head 1.

[0028] The height of the central groove 2 is the same as the height of the hot press head 1, the length of the central groove 2 is 5.7mm, and the width of the central groove 2 is 0.17mm.

[0029] The height of the second right groove 4 and the second left groove 6 is the same as the height of the hot press head 1, the length of the second right groove 4 and the second left groove 6 is 0.2 mm, and the width of the second right groove 4 and the second left groove 6 is 0.05 mm.

[0030] The heights of the first right slide groove 3 and the first left slide groove 5 are the same as the height of the hot press head 1.

[0031] Among them, the first right slide groove 3 and the first left slide groove 5 are rounded edges on the front left and right sides of the central groove 2, and the radius of the rounded edges is 0.05mm.

[0032] Working Principle: In this technical solution, ACF adhesive is pre-applied to the PCB of the module, then the FPC is applied to the PCB and aligned. The hot press head 1 presses and cures the FPC to the PCB. Because the conductive particles are 10µm, the particle flatness ratio after pressing is required to be 14-18µm, necessitating high flatness of the pressing surface. Currently, the height difference between the ink layer and copper layer of the PCB & FPC affects the flatness of the hot press head and the pressing surface. To avoid this, the hot press head is designed to avoid this issue by changing from a completely flat surface to a hollow center. The inner width of the hot press head has a tolerance of 0.2mm on each side compared to the inner ink width of the PCB & FPC, thus avoiding interference from the ink layer during hot press pressing. A height of 0.170mm is reserved in the hollow center to prevent the FPC from bulging during hot pressing and affecting the overall flatness of the back of the product. Slight pressure is applied in the center to prevent the FPC from lifting during the pressing process. To prevent ACF from overflowing onto the FPC and forming raised glue lines, a step is cut out on the outside of the hot press head to avoid glue overflow and forming protrusions. The step is designed with a width of 0.2mm and a height of 0.05mm on each side.

[0033] In summary, this technical solution involves pre-applying ACF adhesive to the PCB of the module, then attaching and aligning the FPC to the PCB, and finally bonding the FPC to the PCB using a hot press head 1. Because the conductive particles are 10µm, a particle flatness ratio of 14-18µm is required after pressing, necessitating high flatness of the pressing surface. Currently, the height difference between the ink layer and the copper layer of the PCB & FPC affects the flatness of the hot press head and the pressing surface. To address this, the hot press head is designed to avoid this issue by changing from a completely flat surface to a hollowed-out design. The inner width of the hot press head has a tolerance of 0.2mm on each side compared to the inner ink width of the PCB & FPC, thus avoiding interference from the ink layer during hot press pressing. A height of 0.170mm is reserved in the hollowed-out area to prevent the FPC from bulging during hot pressing and affecting the overall flatness of the back of the product. This creates slight pressure in the middle, preventing the FPC from lifting during the pressing process. To prevent ACF from overflowing onto the FPC and forming raised glue lines, a step is cut out on the outside of the hot press head to avoid glue overflow and forming protrusions. The step is designed with a width of 0.2mm and a height of 0.05mm on each side.

[0034] In summary, the ACF process hot press head structure of this technical solution, through the coordinated use of the hot press head 1, the central groove 2, the first right slide groove 3, the second right groove 4, the first left slide groove 5, and the second left groove 6, results in a stronger pressing effect; flatness is controlled within 0.12mm, and particle crushing effect is improved, reducing the previous electrical function failure rate of 2% to 0.02%. Furthermore, the coordinated use of the hot press head 1, the central groove 2, the first right slide groove 3, the second right groove 4, the first left slide groove 5, and the second left groove 6 reduces the number of processes. Previously, the overflow of adhesive in the module required a scraping process due to exceeding the size limit; after the improvement of the overflow, scraping is no longer necessary. This design also enhances versatility, allowing it to be used in all camera ACF processes, and standardizes the design specifications.

[0035] This utility model is not limited to the above-described embodiments. Anyone should know that structural changes made under the guidance of this utility model, and any technical solutions that are the same as or similar to this utility model, fall within the protection scope of this utility model. Technical aspects, shapes, and structures not described in detail in this utility model are all publicly known technologies.

Claims

1. A novel ACF process hot press head structure, comprising a hot press head (1), characterized in that: The hot press head (1) has a central groove at the front end, a second right groove (4) at the right side of the front end, a second left groove (6) at the left side of the front end, a first right sliding groove (3) at the right side of the front end of the central groove (2), and a first left sliding groove (5) at the left side of the front end of the central groove (2).

2. The novel ACF process hot press head structure according to claim 1, characterized in that: The hot press head assembly (7) is fixedly connected to the rear side of the hot press head (1), and the height of the hot press head assembly (7) is the same as the height of the hot press head (1).

3. The novel ACF process hot press head structure according to claim 1, characterized in that: The height of the central groove (2) is the same as the height of the hot press head (1), the length of the central groove (2) is 5.7 mm, and the width of the central groove (2) is 0.17 mm.

4. The novel ACF process hot press head structure according to claim 1, characterized in that: The height of the second right groove (4) and the second left groove (6) is the same as the height of the hot press head (1). The length of the second right groove (4) and the second left groove (6) is 0.2 mm, and the width of the second right groove (4) and the second left groove (6) is 0.05 mm.

5. The novel ACF process hot press head structure according to claim 1, characterized in that: The height of the first right slide groove (3) and the first left slide groove (5) is the same as the height of the hot press head (1).

6. The novel ACF process hot press head structure according to claim 1, characterized in that: The first right slide groove (3) and the first left slide groove (5) are rounded edges on the front left and right sides of the central groove (2), and the radius of the rounded edges is 0.05mm.

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