Chip surface mounting process

Abstract

The invention relates to a chip surface mounting technology which comprises the following steps that a chip is configured in a flexible circuit board, and the length direction of the chip intersects with the conveying direction of the flexible circuit board; pre-pasting a cooling fin film on the first surface of the chip, wherein the first surface of the chip is horizontal to the surface of the flexible circuit board; the part, not in contact with the chip, of the cooling fin film covers the flexible circuit board in a suspended mode. The chip configured in the flexible circuit board is conveyed to a rolling station along a first direction; rolling a partial region of the surface of the cooling fin film from the first end of the cooling fin film to the second end of the cooling fin film by adopting a roller on the surface of the cooling fin film along the length direction of the chip; all the cooling fin films are rolled on the surfaces of the cooling fin films in the length direction of the chip from the second ends of the cooling fin films to the first ends of the cooling fin films through a roller, and the phenomena of bumps, bubbles, deformation of the cooling fin films and the like generated after the cooling fin films are rolled can be effectively eliminated through two-section type rolling in the positive direction and the negative direction.

Description

Technical Field

[0001] The present application relates to the field of chip mounting technology, and in particular to a chip surface mounting process. Background Art

[0002] Flexible circuit boards, also known as soft circuit boards and flexible circuit boards, are highly favored for their excellent properties such as light weight, thin thickness, and free bending and folding. In the preparation process of flexible circuit boards, it is necessary to stick a heat sink film on the chip on the circuit board. Usually, the thickness of the chip is greater than the thickness of the circuit board. Therefore, when the chip is installed on the circuit, a part of it must be higher than the surface of the chip. In traditional processes, the heat sink film is generally rolled on the surface of the chip using a roller. However, after rolling, the heat sink film often has bulging, deformation, bubbles, and cracks, which affects the use of flexible circuit boards. At present, adjusting the pressure of the roller, replacing rollers with different hardness, etc. cannot effectively change the occurrence of the above-mentioned defective products. Therefore, it is urgent to provide a process that can improve the yield rate of the process of mounting heat sink films on chips on flexible circuit boards. Summary of the invention

[0003] The purpose of this application is to provide a chip surface mounting process for solving the problems of heat sink film deformation, bulging, etc. that occur when the heat sink film is mounted on the chip surface.

[0004] The technical solution of the present invention is: a chip surface mounting process, comprising the following steps:

[0005] The chip is arranged in the flexible circuit board, the chip is higher than the surface of the flexible circuit board, and the length direction of the chip intersects with the conveying direction of the flexible circuit board;

[0006] Pre-attaching a heat sink film to the first surface of the chip, wherein the first surface of the chip is level with the surface of the flexible circuit board;

[0007] The heat sink film is partially suspended above the flexible circuit board where it is not in contact with the chip;

[0008] The chip configured in the flexible circuit board is conveyed to a rolling station along a first direction;

[0009] Using a roller to roll a partial area of ​​the surface of the heat sink film from the first end of the heat sink film to the second end of the heat sink film along the length direction of the chip;

[0010] A roller is used to roll the entire heat sink film on the surface of the heat sink film from the second end of the heat sink film to the first end of the heat sink film along the length direction of the chip.

[0011] Preferably, a roller is used to roll on the surface of the heat sink film from left to right along the length direction of the chip, and the roller rolls on the surface of the heat sink film to half of the length direction of the chip.

[0012] Preferably, a rolling mechanism, a flexible circuit board conveying mechanism and a bearing mechanism are provided at the rolling station, the rolling mechanism is provided with the roller, and the flexible circuit board conveying mechanism is provided between the roller and the bearing mechanism.

[0013] Preferably, the rolling mechanism includes a first rolling drive mechanism capable of moving along the length direction of the chip and a second rolling drive mechanism capable of moving toward the chip direction, the second rolling drive mechanism is installed at the movable end of the first rolling drive mechanism, and the movable section of the second rolling drive mechanism is equipped with the roller.

[0014] Preferably, after the second rolling drive mechanism moves toward the chip for the first time, the first rolling drive mechanism advances a first stroke along the length direction of the chip, and after the second rolling drive mechanism moves away from the chip, the first rolling drive mechanism advances a second stroke along the length direction of the chip, and when the second rolling drive mechanism moves toward the chip for the second time, the first rolling drive mechanism retreats along the length direction of the chip to the sum of the distances of the first stroke and the second stroke.

[0015] Preferably, the bearing mechanism comprises a supporting block, the flexible circuit board is placed on the supporting block, a groove is provided at one end of the supporting block close to the flexible circuit board, and the chip is located on the groove.

[0016] Preferably, the first rolling drive mechanism is a first cylinder fixed to the rolling station, and the second rolling drive mechanism is a second cylinder fixed to the movable end of the first cylinder, and the roller is mounted on the movable end of the second cylinder.

[0017] Preferably, the roller applies a reciprocating force along the length direction of the heat sink film to the heat sink film in the direction of the support block.

[0018] Preferably, the hardness of the roller material is 50A-90A.

[0019] Compared with the prior art, the advantages of this application are:

[0020] (1) After the heat sink film is pre-laminated on the chip surface, the present application uses a two-stage rolling method. First, a portion of the heat sink film is rolled onto the chip surface along a first direction by a roller, and then the entire heat sink film is rolled onto the chip from the other end of the chip in a second direction opposite to the first direction. This can effectively eliminate bulging, blistering, and other phenomena caused by rolling the heat sink film.

[0021] (2) The segmented rolling method is used to overcome the defective products caused by excessive stretching of the heat sink film itself. At the same time, the two-stage rolling method can achieve a better adhesion effect between the heat sink film and the chip.

[0022] (3) The first section is rolled to the middle of the chip, and the second section is rolled back from the other end of the chip. The heat sink film is best attached to the chip surface.

[0023] (4) The rolling mechanism has a compact structure and a reasonable action design. It adopts two sets of rolling drive mechanisms, which can not only realize forward rolling along the length direction of the chip, but also break contact after rolling forward, and then roll backward in the opposite direction of the forward rolling. The rolling action is reasonable and the rolling effect is uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present application is further described below in conjunction with the accompanying drawings and embodiments:

[0025] Figure 1 A schematic diagram of a chip surface mounting process chip and a flexible circuit board in an embodiment of the present application;

[0026] Figure 2 This is a schematic diagram of the overall process of a chip surface mounting process for this application;

[0027] Figure 3 This is a schematic diagram of a chip surface mount rolling station structure for this application;

[0028] Figure 4 This is a schematic diagram of the chip surface mounting rolling station structure for this application.

[0029] in:

[0030] 1. Rolling mechanism;

[0031] 11. a first rolling drive mechanism, 12. the second rolling drive mechanism, 13. a roller;

[0032] 2. Flexible circuit board conveying mechanism;

[0033] 3. Carrying mechanism;

[0034] 31. support block, 310. groove, 311. negative pressure vent; DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiment is only one embodiment of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0036] "Embodiment" referred to herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present application. In the description of the embodiment of the present application, it should be understood that the terms "first", "second" and "third" etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second" and "third" etc. may include one or more of the features explicitly or implicitly. Moreover, the terms "first", "second" and "third" etc. are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiment of the present application described here can be implemented in an order other than illustrated or described here. In addition, the terms "including" and "for" and any of their variations are intended to cover non-exclusive inclusions.

[0037] like Figure 1 As shown, this embodiment provides a chip surface mounting process, including the following steps:

[0038] S1: The chip is configured in a flexible circuit board;

[0039] During the production process of the flexible circuit board, a chip is installed on the flexible circuit board. Usually, the flexible circuit board is stored in the form of a roll and then processed and assembled. In this embodiment, the chip is a bar chip. After the bar chip is installed in the flexible circuit board, it should be 3-5 mm higher than the surface of the circuit board. The length direction of the chip intersects with the conveying direction of the flexible circuit board. In this embodiment, the length direction of the chip is perpendicular to the conveying direction of the flexible circuit board.

[0040] S2: pre-attaching a heat sink film to the first surface of the chip;

[0041] Usually, the heat sink film is a patch with heat dissipation effect such as aluminum film, stainless steel film, etc., and there are also patches made of graphene film. The inner surface of the heat sink film that contacts the chip is coated with glue. First, the inner surface of the heat sink film is pre-laminated on the chip. The surface area of ​​the heat sink film is larger than the surface area of ​​the chip to be laminated. In some embodiments, the surface area of ​​the heat sink film exceeds 5-10 times the surface area of ​​the chip to be laminated. Therefore, the heat sink film is partially pre-laminated on the surface of the chip, and the part where the heat sink film is not in contact with the chip is partially suspended and covered above the flexible circuit board. In a preferred embodiment of the present application, the middle position of the heat sink film is pre-laminated on the surface of the chip, and the surface of the chip to be laminated is level with the surface of the flexible circuit board.

[0042] S3: The chip configured in the flexible circuit board is transported to a rolling station along a first direction;

[0043] The flexible circuit board is transported to the rolling station along the first direction by the conveying mechanism, and is ready to complete the rolling of the heat sink film at the rolling station. The conveying mechanism moves forward each time by a width of the flexible circuit board.

[0044] S4: using a roller to roll a portion of the surface of the heat sink film forward along the length direction of the chip;

[0045] like Figure 2 As shown, a rolling mechanism 1, a flexible circuit board conveying mechanism 2 and a bearing mechanism 3 are provided in the rolling station, and the flexible circuit board conveying mechanism 2 is provided between the rolling mechanism 1 and the bearing mechanism 3. The rolling mechanism 1 includes a first rolling drive mechanism 11 that can move along the length direction of the chip and a second rolling drive mechanism 12 that can move toward the chip. In this embodiment, the first rolling drive mechanism 11 and the second rolling drive mechanism 12 are both cylinders, and the second rolling drive mechanism 12 is installed at the movable end of the first rolling drive mechanism 11, and the movable section of the second rolling drive mechanism 12 is installed with a roller 13.

[0046] After the flexible circuit board is conveyed to the rolling station, the second rolling drive mechanism 12 drives the roller 13 to move toward the chip for the first time. At this time, the roller 12 is pressed on the heat sink film, and then the first rolling drive mechanism 11 advances the first stroke along the length direction of the chip. During this process, the first rolling drive mechanism 11 drives the roller 12 to achieve the first rolling on the surface of the heat sink film. It should be noted that at this time, the displacement stroke of the first rolling drive mechanism 11 will not exceed the length of the chip, that is, the roller 12 only rolls a part of the heat sink film onto the chip and the flexible circuit board. This is the heat sink film after being rolled to complete the coverage of the chip and the flexible circuit board. During the rolling process of the roller 13, the part of the heat sink film that is not in contact with the flexible circuit board gradually fits onto the flexible circuit board. Since the roller 13 only rolls a part of the distance, the unrolled part is still in contact with the air. Therefore, no bubbles, bulges, etc. will appear on the surface of the heat sink film that has been rolled. Although the heat sink film close to the chip position does not completely contact the chip and the flexible circuit board, when the roller 13 only rolls a part, no ruffles or cracks will appear.

[0047] S5: Use a roller to roll the surface of the heat sink film backward along the length direction of the chip in the direction opposite to the forward direction, and the distance that the roller rolls on the surface of the heat sink film exceeds the length of the chip. In a preferred embodiment of the present application, the hardness of the roller material is 50A-90A.

[0048] After the roller 13 rolls part of the heat sink film, the second rolling drive mechanism 12 moves in the direction away from the chip, lifts the roller and leaves the chip, and then the first rolling drive mechanism 11 continues to move forward for a second stroke along the length direction of the chip, pushing the roller 13 to the other end close to the heat sink film. After the second rolling drive mechanism 12 moves toward the chip for the second time and the roller 13 is pressed on the surface of the heat sink film, the first rolling drive mechanism 11 retreats along the length direction of the chip to the sum of the first stroke and the second stroke, that is, the roller 13 rolls the entire heat sink film back from the other end of the heat sink film to complete the rolling action on the heat sink film.

[0049] After the first rolling of the roller, since the heat sink film itself has ductility and there is a chip supported between the heat sink film and the flexible circuit board, if it continues to roll forward at this time, if the pressure is too small, bubbles and bulging will easily occur, and if the pressure is too large, the heat sink film will easily deform, resulting in ruffles and cracks. Therefore, after the roller 13 rolls a certain distance, it rolls back from the other end face of the heat sink film to avoid excessive stretching and deformation of the heat sink film. At the same time, since the first rolling ensures that there are no bubbles and bulging, the second rolling back avoids the occurrence of the above-mentioned defective products.

[0050] In a preferred embodiment of the present application, the second rolling drive mechanism 12 drives the roller 13 to move toward the chip for the first time, and the distance of the first stroke is half of the heat sink film. After the second rolling back, the effect is better.

[0051] In a preferred embodiment of the present application, the supporting mechanism 3 includes a supporting block 31, the flexible circuit board is placed on the supporting block 31, a groove 310 is provided at one end of the supporting block 31 close to the flexible circuit board, the chip mounted on the flexible circuit board is located above the groove 310 as a whole, and negative pressure vents 311 are provided on both sides of the groove 310. After the flexible circuit board is conveyed to the supporting block 31, the negative pressure vents 311 are connected to negative pressure to adsorb the flexible circuit board. At this time, the chip is located above the groove 310. When the roller 13 rolls the heat sink film, the groove 310 can provide a buffering force to ensure the lamination effect.

[0052] The above embodiments are only for illustrating the technical concept and features of the present application, and their purpose is to enable people familiar with this technology to understand the content of the present application and implement it accordingly, and they cannot be used to limit the scope of protection of the present application. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present application is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present application.

Claims

1. A chip surface mounting process, characterized in that: The following steps are involved: The chip is arranged in the flexible circuit board, the chip is higher than the surface of the flexible circuit board, and the length direction of the chip intersects with the conveying direction of the flexible circuit board; Pre-attaching a heat sink film to the first surface of the chip, wherein the first surface of the chip is level with the surface of the flexible circuit board; The heat sink film is partially suspended above the flexible circuit board where it is not in contact with the chip; The chip configured in the flexible circuit board is conveyed to a rolling station along a first direction; Using a roller to roll a partial area of ​​the surface of the heat sink film from the first end of the heat sink film to the second end of the heat sink film along the length direction of the chip; A roller is used to roll the entire surface of the heat sink film from the second end of the heat sink film to the first end of the heat sink film along the length direction of the chip.

2. A chip surface mounting process according to claim 1, characterized in that: The method of using a roller to roll a partial area of ​​the surface of the heat sink film from the first end of the heat sink film to the second end of the heat sink film along the length direction of the chip includes rolling the roller on the surface of the heat sink film to half of the length direction of the chip.

3. A chip surface mounting process according to claim 1, characterized in that: The rolling station is provided with a rolling mechanism, a flexible circuit board conveying mechanism and a bearing mechanism, the rolling mechanism is provided with the roller, and the flexible circuit board conveying mechanism is provided between the roller and the bearing mechanism.

4. A chip surface mounting process according to claim 3, characterized in that: The rolling mechanism includes a first rolling drive mechanism that can move along the length direction of the chip and a second rolling drive mechanism that can move toward the chip direction. The second rolling drive mechanism is installed at the movable end of the first rolling drive mechanism, and the movable section of the second rolling drive mechanism is equipped with the roller.

5. A chip surface mounting process according to claim 4, characterized in that: After the second rolling drive mechanism moves toward the chip for the first time, the first rolling drive mechanism advances a first stroke along the length direction of the chip. After the second rolling drive mechanism moves away from the chip, the first rolling drive mechanism advances a second stroke along the length direction of the chip. When the second rolling drive mechanism moves toward the chip for the second time, the first rolling drive mechanism retreats along the length direction of the chip to the sum of the distances of the first stroke and the second stroke.

6. A chip surface mounting process according to claim 5, characterized in that: The bearing mechanism comprises a supporting block, the flexible circuit board is placed on the supporting block, a groove is arranged at one end of the supporting block close to the flexible circuit board, and the chip is located on the groove.

7. A chip surface mounting process according to claim 5, characterized in that: The first rolling drive mechanism is a first cylinder fixed to the rolling station, and the second rolling drive mechanism is a second cylinder fixed to the movable section of the first cylinder, and the movable section of the second cylinder is equipped with the roller.

8. A chip surface mounting process according to claim 5, characterized in that: The roller applies a reciprocating force along the length direction of the heat sink film to the heat sink film in the direction of the support block.

9. A chip surface mounting process according to any one of claims 1 to 7, characterized in that: The hardness of the roller material is 50A-90A.

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