Sample preparation method of resin sheet

Abstract

The invention discloses a sample preparation method of a resin sheet, and relates to the technical field of dielectric property testing of hole plugging resin. The invention relates to a sample preparation method of a resin sheet. The sample preparation method comprises the following steps: film pasting: pasting a layer of PI adhesive tape on a metal sheet; pattern carving: carving a designed pattern on the PI adhesive tape; tearing off the adhesive tape: tearing off the PI adhesive tape of the carved pattern area; resin filling: filling the pattern area after the PI adhesive tape is torn off with resin; baking: baking the metal sheet with the resin, and curing the resin; tearing off the adhesive: tearing off the residual PI adhesive tape; and soaking and demolding: soaking the metal sheet with the resin in water to separate the metal sheet from the resin sheet to obtain the resin sheet. The metal sheet serves as a substrate, the resin sheet is soaked in water after being baked and cured, water molecules enter the space between the metal sheet and the resin sheet, the surface tension of the resin sheet is increased, molecular bonds between the resin sheet and the metal sheet are broken, and the problem that the resin sheet is broken in the mold taking process is solved.

Description

Technical Field

[0001] The invention relates to the technical field of dielectric performance testing of plugging resin, and in particular to a sample preparation method of a resin sheet. Background Art

[0002] PCB plugging resin refers to the resin material used to fill metallized holes during the PCB manufacturing process. In PCB manufacturing, when multi-layer PCBs are assembled, connected, and transmit signals, it is necessary to use holes between layers to achieve electrical connections and disconnections at different levels. Due to processing and application requirements, it is necessary to ensure that there are no gaps or bubbles inside some holes and to provide good electrical connections and mechanical strength, which requires the use of plugging resin to fill these holes. With the development of science and technology, the application environment of PCBs has put forward higher requirements on the comprehensive performance of PCBs. Among them, PCBs used for high-frequency and high-speed signal transmission also put forward higher matching requirements for the dielectric properties of plugging resins.

[0003] The dielectric property test of plugging resin requires the preparation of thin sheets with regular shape, smooth surface and uniform overall thickness. There are different ways to prepare samples in the industry, the most common of which are silicone mold sample preparation and filter paper molding sample preparation. However, they all face problems such as difficulty in removing the mold after the resin is cured and the resin sheet breaking during the removal process. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a method for preparing a sample of a resin sheet, which can reduce the difficulty of taking a mold and avoid the problem of resin sheet fragmentation during the molding process.

[0005] The present invention provides a method for preparing a resin sheet, comprising the following steps:

[0006] Film pasting: Paste a layer of PI tape on the metal sheet;

[0007] Graphic engraving: engrave the designed graphics on the PI tape;

[0008] Remove the adhesive tape: Tear off the PI tape in the engraved graphic area;

[0009] Resin filling: Fill the resin into the graphic area after the PI tape is torn off;

[0010] Baking: Baking the metal sheet with resin to solidify the resin;

[0011] Secondary adhesive removal: tear off the remaining PI tape;

[0012] Immersion demoulding: Soak the metal sheet with resin in water to separate the metal sheet and the resin sheet to obtain a resin sheet.

[0013] A method for preparing a sample of a resin sheet according to an embodiment of the present invention has at least the following beneficial effects: a metal sheet is used as a substrate, and the resin sheet is immersed in water after being baked and cured, so that water molecules enter between the metal sheet and the resin sheet, thereby increasing the surface tension of the resin sheet, breaking the molecular bonds between the resin sheet and the metal sheet, and increasing the lubrication between the two, thereby reducing the difficulty of molding and avoiding the problem of resin sheet breakage during the molding process.

[0014] According to the resin sheet sample preparation method of the present invention, in the film sticking step, the metal sheet is an aluminum sheet.

[0015] According to the sample preparation method of a resin sheet described in the present invention, in the film pasting step, the thickness of the PI tape is 120 μm.

[0016] According to the resin sheet sample preparation method of the present invention, laser engraving is adopted in the pattern engraving step.

[0017] According to the method for preparing a sample of a resin sheet of the present invention, in the resin filling step, a scraper with a smooth and flat edge is used to scrape the resin onto the graphic area where the tape is torn off.

[0018] According to the resin sheet sample preparation method of the present invention, before the secondary glue peeling step, it also includes a cutting step, in which the metal sheet is divided into a number of small pieces larger than the resin area.

[0019] According to the sample preparation method of a resin sheet of the present invention, after immersion and demoulding, the thickness of the resin sheet is 100 microns to 140 microns.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments;

[0022] Figure 1 It is a processing flow chart of an embodiment of the present invention;

[0023] Figure 2 A top view of the product structure of the adhesive peeling step of a preferred embodiment of the present invention;

[0024] Figure 3 for Figure 2 Sectional view of section AA;

[0025] Figure 4 This is a cross-sectional view of the product structure after the second glue peeling step of a preferred embodiment of the present invention.

[0026] Reference numerals:

[0027] Metal sheet 10 , PI tape 20 , resin sheet 30 . DETAILED DESCRIPTION

[0028] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0030] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0031] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0032] Reference Figures 1 to 4 A method for preparing a resin sheet 30 comprises the following steps:

[0033] Film pasting: Paste a layer of PI tape 20 on the metal sheet 10;

[0034] Graphic engraving: engrave the designed graphics on PI tape 20;

[0035] Remove the adhesive tape: Remove the PI tape 20 from the engraved graphic area;

[0036] Resin filling: Fill the resin into the graphic area after tearing off the PI tape 20;

[0037] Baking: Baking the metal sheet 10 with the resin to solidify the resin;

[0038] Secondary adhesive removal: tear off the remaining PI tape 20;

[0039] Immersion demoulding: The metal sheet 10 with the resin is immersed in water to separate the metal sheet 10 from the resin sheet to obtain the resin sheet 30 .

[0040] Using the metal sheet 10 as a substrate, the resin sheet is immersed in water after baking and curing. Water molecules enter between the metal sheet 10 and the resin sheet 30, increasing the surface tension of the resin sheet 30, breaking the molecular bonds between the resin sheet 30 and the metal sheet 10, and increasing the lubrication between the two, thereby reducing the difficulty of molding and avoiding the problem of resin sheet 30 breaking during the molding process.

[0041] It is worth noting that, in some embodiments of the present invention, in the film-attaching step, the metal sheet 10 is an aluminum sheet.

[0042] It should be noted that the aluminum metal sheet 10 has the advantages of being light in weight and low in price, and is also easy to separate from the resin sheet 30 .

[0043] It is worth noting that, in some embodiments of the present invention, in the film laminating step, the thickness of the PI tape 20 is 120 μm.

[0044] It can be understood that, in some embodiments of the present invention, the thickness of the PI tape 20 determines the thickness of the resin sheet 30 .

[0045] It is worth noting that, in some embodiments of the present invention, laser engraving is used in the graphic engraving step.

[0046] It should be noted that the laser engraving process has obvious advantages in accuracy, flexibility and non-contact processing, and is particularly suitable for small-batch production with high-precision requirements.

[0047] It is worth noting that, in some embodiments of the present invention, in the resin filling step, a scraper with a smooth and flat edge is used to apply the resin to the graphic area where the tape is torn off.

[0048] It can be understood that after the resin is applied to the graphic area where the PI tape 20 is torn off by a scraper, the lower end of the resin is attached to the metal sheet 10 and the upper end is scraped flat by the hanging plate. As long as the edge of the scraper is smooth and flat, the two sides of the resin can be smooth and flat after solidification.

[0049] It is worth noting that, in some embodiments of the present invention, before the secondary peeling step, a slitting step is also included, in which the metal sheet 10 is divided into a number of small pieces larger than the resin area.

[0050] It should be noted that, in order to facilitate demoulding of the resin sheet 30 , the metal sheet 10 may be cut into small pieces after the baking step, and each small piece may be only slightly larger than the size of the resin sheet 30 .

[0051] It should be noted that, in some embodiments of the present invention, the side length of the metal sheet 10 after cutting is 5 mm longer than the side length of the resin sheet 30 .

[0052] It is worth noting that, in some embodiments of the present invention, after immersion and demoulding, the thickness of the resin sheet 30 is 100 micrometers to 140 micrometers.

[0053] It is worth noting that the resin sheet 30 made by the PI tape 20 with a thickness of 120 μm has a thickness ranging from 100 μm to 140 μm after baking and soaking.

[0054] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A method for preparing a resin sheet, characterized in that: The following steps are involved: Film pasting: Paste a layer of PI tape on the metal sheet; Graphic engraving: engrave the designed graphics on the PI tape; Remove the adhesive tape: Tear off the PI tape in the engraved graphic area; Resin filling: Fill the resin into the graphic area after the PI tape is torn off; Baking: Baking the metal sheet with resin to solidify the resin; Secondary adhesive removal: tear off the remaining PI tape; Immersion demoulding: Soak the metal sheet with resin in water to separate the metal sheet and the resin sheet to obtain a resin sheet.

2. The method for preparing a resin sheet according to claim 1, characterized in that: In the film-sticking step, the metal sheet is an aluminum sheet.

3. The method for preparing a resin sheet according to claim 1, characterized in that: In the film lamination step, the thickness of the PI tape was 120 μm.

4. The method for preparing a resin sheet according to claim 1, characterized in that: In the graphic engraving step, laser engraving is adopted.

5. The method for preparing a resin sheet according to claim 1, characterized in that: In the resin filling step, a scraper with a smooth edge is used to apply the resin to the pattern area where the tape is torn off.

6. The method for preparing a resin sheet according to claim 1, characterized in that: Before the secondary peeling step, a slitting step is also included, in which the metal sheet is divided into a number of small pieces larger than the resin area.

7. The method for preparing a resin sheet according to claim 1, characterized in that: After immersion demoulding, the thickness of the resin sheet is 100 microns to 140 microns.

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