Manufacturing method of packaged circuit board and packaged circuit board

Abstract

The invention discloses a manufacturing method of a packaging circuit board and the packaging circuit board, and belongs to the technical field of packaging circuit boards, and the manufacturing method comprises the following steps: carrying out groove fishing treatment on a substrate, attaching a back film to the bottom surface of the substrate, placing the substrate on a supporting plate, placing devices to be embedded in corresponding grooves one by one, and pasting the devices to the back film; pouring a resin material into the scooping groove, covering the non-back film side of the substrate with a protective steel plate, and then carrying out curing treatment to obtain a resin layer; removing the back film on the substrate, grinding the resin layer, sequentially adding an insulating layer and a metal layer on the two sides of the substrate, carrying out lamination treatment, carrying out circuit processing treatment on the circuit board after lamination treatment, realizing communication between the embedded device and the metal layer, and manufacturing a first layer of circuit board; a plurality of functional circuit layers are overlaid on the two sides of the first layer of circuit board, and manufacturing of the packaging circuit board is achieved. According to the invention, low-cost and high-precision embedded circuit board packaging manufacturing can be realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of packaging circuit boards, and particularly relates to a packaging circuit board manufacturing method and a packaging circuit board. BACKGROUND

[0002] The packaging circuit board refers to a circuit board with built-in components, which realizes the integration, low parasitic, high reliability and low cost of the circuit board. At present, high-end servers, AI acceleration cards, millimeter wave communication, advanced mobile devices and new energy vehicle industries are developing rapidly. These industries have put forward new challenges to energy efficiency, integration, performance and reliability, and there is an urgent need for a low-cost and high-performance packaging circuit board.

[0003] The inner-buried packaging product has the advantages of short interconnection, low parasitic and low height, which can effectively improve the conversion efficiency, reduce the energy consumption, shorten the heat dissipation path and improve the reliability. At present, it has been widely used in SIP and COWOS. At present, the ABF material commonly used in inner-buried products is high in cost and difficult to obtain, which greatly limits the production capacity and application of the product. In addition, the traditional ABF material has poor flowability at a certain temperature, and cannot be fully filled, which causes some reliability problems. In addition, the device is attached to the ABF material, and the traditional ABF has no adhesion. The glue flow under high temperature will squeeze the device, causing the device to move position, and finally causing the blind hole to be unable to lead out the electrode inside the circuit board to the device. SUMMARY

[0004] The purpose of the application is to provide a packaging circuit board manufacturing method and a packaging circuit board, which can solve the problems of high cost and inability to realize high-precision installation and fixation of the buried device of the existing buried packaging circuit board.

[0005] To achieve the above purpose, the technical scheme of the application is as follows:

[0006] In a first aspect, the application provides a packaging circuit board manufacturing method, which comprises the following steps:

[0007] The substrate is subjected to slotting treatment, the back film is attached to the bottom surface of the substrate and placed on the support plate, the device to be buried is placed in the corresponding slot one by one and attached to the back film;

[0008] The resin material is poured into the slot, the non-back film side of the substrate is covered with a protective steel plate, and then solidification treatment is performed to obtain a resin layer;

[0009] The back film on the substrate is removed, the resin layer is subjected to grinding treatment, the insulating layer and the metal layer are sequentially added to both sides of the substrate, and compression treatment is performed. The circuit board after compression treatment is subjected to circuit processing treatment to realize the communication between the buried device and the metal layer, and a first layer circuit board is manufactured.

[0010] Several functional circuit layers are superimposed on both sides of the first circuit board to realize the fabrication of the packaged circuit board.

[0011] The back film includes a pressure-sensitive adhesive layer and a thermally expanded foaming layer. The pressure-sensitive adhesive layer is adhered to the bottom surface of the substrate to fix the device to be embedded, and the thermally expanded foaming layer is adhered to the support plate to prevent the back film from warping or deforming.

[0012] The pressure-sensitive adhesive layer has a higher temperature tolerance than the thermal foaming decomposition layer.

[0013] The resin material is a room-temperature liquid resin with a low coefficient of thermal expansion, which is less than 60 ppm.

[0014] The embedded devices are capacitors, inductors, or logic chips, and the embedding method can be vertical, horizontal, matrix arrangement, or single slot.

[0015] The combined thickness of the insulating layer and the resin layer is within the target thickness range to ensure that the insulation performance meets the requirements.

[0016] The process of injecting resin material into the trough is carried out in a vacuum environment, which can eliminate air and volatiles and eliminate the source of defects; at the same time, it optimizes the flow and wetting ability of the resin, ensuring uniform filling and interfacial bonding strength.

[0017] The process of removing the back film from the substrate includes: first heating to separate the support plate and the back film, second heating to separate the back film and the substrate, and removing residual adhesive from the substrate.

[0018] Secondly, the present invention provides a packaged circuit board manufactured based on the above-described method for manufacturing a packaged circuit board, comprising the first circuit board layer and a plurality of functional circuit layers superimposed on both sides of the first circuit board layer.

[0019] An insulating layer is filled between the first circuit board layer and each functional circuit layer, and electrical connections between the first circuit board layer and each functional circuit layer are achieved through blind vias.

[0020] Beneficial effects: The present invention provides a method for manufacturing a packaged circuit board and the packaged circuit board itself, which enables low-cost, high-precision embedded circuit board packaging. It adopts a resin filling process, using resin that is fluid at room temperature. Under low pressure conditions, it can fully fill slots or gaps of various sizes. Before filling the resin, a high-precision pick-and-place machine is used to accurately fix the device at the designated position on the back film with an accuracy of less than 5µm. Under low pressure conditions, the horizontal shear force on the device is reduced, and the device is adhered to the back film with a certain degree of adhesion. The device is accurately positioned, which can meet the needs of high-precision alignment products such as small electrodes. Moreover, it is lower in cost and easier to obtain than ABF material. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the method for manufacturing the packaged circuit board of the present invention;

[0022] Figure 2 This is a schematic diagram of the packaging circuit board of the present invention.

[0023] In the figure, 1-substrate; 2-back film; 3-resin layer; 4-insulating layer; 5-metal layer; 6-embedded device. Detailed Implementation

[0024] To illustrate in detail the technical solutions adopted by the present invention to achieve the intended technical objectives, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Furthermore, the technical means or technical features in the embodiments of the present invention can be replaced without creative effort. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0025] Example 1

[0026] refer to Figure 1 As shown, a method for manufacturing a packaged circuit board includes the following steps:

[0027] Step S1: Perform a slotting process on the substrate, attach a back film to the bottom surface of the substrate, place it on a support plate, and place the devices to be embedded one by one into the corresponding slots and attach them to the back film.

[0028] The back film 2 includes a pressure-sensitive adhesive layer and a thermally foamed decomposition layer. Tension on one side of the back film 2 can cause warping problems. The support plate can effectively prevent the back film from warping and deforming, and improve the accuracy of embedded device installation.

[0029] The back film 2 is pressed onto the substrate 1 under certain pressure and temperature conditions using a laminating machine. The processing temperature is 150℃ to ensure that the back film 2 and the substrate 1 are fully bonded together without problems such as peeling, wrinkles, or bubbles.

[0030] The substrate 1 with the back film is fixed on the table of a high-precision pick and place machine by vacuum or clamping. The high-precision pick and place machine is used to attach active or passive devices to the back film 2 inside the substrate 1. The back film 2 has good adhesion to fix the embedded device 6 at the corresponding placement position.

[0031] The embedded device 6 can be an active or passive device such as a capacitor, inductor, or logic chip, and the embedding method can be vertical, horizontal, arrayed, or a single slot.

[0032] Step S2: Place the substrate in a vacuum environment, pour resin material into the trough to fill the gap between the embedded device and the substrate, cover the non-back film side of the substrate with a protective steel plate and then perform curing treatment to obtain the resin layer.

[0033] In this embodiment, an ultra-low coefficient of thermal expansion resin material is used, with a coefficient of thermal expansion of less than 60ppm. It is liquid at room temperature and has good fluidity, and can fully fill the groove and gap in a vacuum environment.

[0034] The cured resin layer 3 can be embedded in the device for high-precision positioning and stability.

[0035] Step S3: Remove the back film on the substrate, grind the resin layer to ensure the surface of the resin layer is flat, add an insulating layer and a metal layer to both sides of the substrate in sequence, and perform a lamination process. Perform circuit processing on the laminated circuit board to realize the connection between the embedded device and the metal layer, and make the first circuit board.

[0036] The process of removing the back film 2 from the substrate 1 includes: a first heating to separate the support plate from the back film 2, a second heating to separate the back film 2 from the substrate 1, and removal of residual adhesive on the substrate 1. The thermally foamed decomposition layer of the back film 2 decomposes at 170°C for three minutes, achieving separation from the support plate. The pressure-sensitive adhesive layer is heat-resistant up to 180°C. After the support plate is separated, the pressure-sensitive adhesive layer can be peeled off from the bottom surface of the substrate 1, and a small amount of residual adhesive on the back film side of the substrate 1 can be removed using methods such as horizontal liquid adhesive removal and dry ice removal.

[0037] The combined thickness of insulating layer 4 and resin layer 3 must be within the target thickness range to ensure that the insulation meets the requirements. The insulation thickness is required to be 10-30μm. The actual thickness will be further adjusted according to the thickness and impedance requirements of the product.

[0038] The circuit processing adopts traditional circuit board technology, including laser engraving, glue removal, electroplating, etc., to achieve electrical connection between the embedded device 6 and the metal layer 5;

[0039] Step S4: Stack several functional circuit layers on both sides of the first circuit board to realize the production of the packaged circuit board.

[0040] Example 2

[0041] refer to Figure 2 As shown, a packaged circuit board, fabricated based on the method described in Embodiment 1, includes a first circuit board layer as described in Embodiment 1 and several functional circuit layers superimposed on both sides of the first circuit board layer. An insulating layer is filled between the first circuit board layer and each functional circuit layer, and electrical connections between the first circuit board layer and each functional circuit layer are achieved through blind vias or other means.

[0042] In summary, the present invention provides a method for manufacturing a packaged circuit board and the packaged circuit board itself, enabling low-cost, high-precision embedded circuit board packaging. It employs a resin-filling process using resin that is fluid at room temperature, allowing for the full filling of slots or gaps of various sizes under low pressure. Before resin filling, a high-precision pick-and-place machine precisely fixes the devices to designated positions on the back film with an accuracy of less than 5µm. Under low pressure, the horizontal shear force on the devices is reduced, and the devices are adhered to the back film with a certain degree of adhesiveness, resulting in precise device positioning. This meets the requirements of high-precision alignment products with small electrodes and is more cost-effective and readily available than ABF materials.

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the purpose of simplifying the description of this invention and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for manufacturing a packaged circuit board, characterized in that, Includes the following steps: The substrate is subjected to a grooving process. A back film is attached to the bottom surface of the substrate and placed on a support plate. The devices to be embedded are placed one by one into the corresponding grooves and attached to the back film. Resin material is poured into the trough, and a protective steel plate is added to the non-back film side of the substrate before curing to obtain a resin layer. Remove the back film on the substrate, grind the resin layer, add an insulating layer and a metal layer to both sides of the substrate in sequence, and then press them together. Process the circuit board after pressing to achieve the connection between the embedded device and the metal layer, and make the first circuit board. Several functional circuit layers are superimposed on both sides of the first circuit board to realize the fabrication of the packaged circuit board.

2. The method for manufacturing a packaged circuit board according to claim 1, characterized in that, The back film includes a pressure-sensitive adhesive layer and a thermally foamed decomposition layer. The pressure-sensitive adhesive layer is adhered to the bottom surface of the substrate to fix the device to be embedded, and the thermally foamed decomposition layer is adhered to a support plate.

3. The method for manufacturing a packaged circuit board according to claim 2, characterized in that, The pressure-sensitive adhesive layer has a higher temperature tolerance than the thermal foaming decomposition layer.

4. The method for manufacturing a packaged circuit board according to claim 1, characterized in that, The resin material is a room-temperature liquid resin with a low coefficient of thermal expansion, which is less than 60 ppm.

5. The method for manufacturing a packaged circuit board according to claim 1, characterized in that, The embedded devices are capacitors, inductors, or logic chips, and the embedding method can be vertical, horizontal, matrix arrangement, or single slot.

6. The method for manufacturing a packaged circuit board according to claim 1, characterized in that, The combined thickness of the insulating layer and the resin layer is within the target thickness range.

7. The method for manufacturing a packaged circuit board according to claim 1, characterized in that, The process of pouring resin material into the trough is carried out in a vacuum environment.

8. The method for manufacturing a packaged circuit board according to claim 1, characterized in that, The process of removing the back film from the substrate includes: first heating to separate the support plate and the back film, second heating to separate the back film and the substrate, and removing residual adhesive from the substrate.

9. A packaged circuit board manufactured according to the manufacturing method of any one of claims 1 to 8, comprising the first circuit board layer and a plurality of functional circuit layers superimposed on both sides of the first circuit board layer.

10. The packaged circuit board according to claim 9, characterized in that, An insulating layer is filled between the first circuit board layer and each functional circuit layer, and electrical connections between the first circuit board layer and each functional circuit layer are achieved through blind vias.

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