CN109743840B - Coreless substrate and packaging method thereof - Google Patents

Abstract

The invention provides a coreless substrate and a packaging method thereof. The coreless substrate packaging method comprises the following steps: pasting a film on the substrate; exposing the substrate; etching and grooving the metal layer of the substrate to recess the metal layer and form a groove; pressing a filling piece on the substrate so that the filling piece fills the groove; and laminating, electroplating and processing the substrate to form the packaging substrate. The filling piece and the groove form a dam structure to isolate the liquid medicine. Therefore, the liquid medicine can be prevented from permeating into the coreless substrate, the performance and the service life of the coreless substrate are ensured, the yield of the finished product and the related electrical performance of the finished product are improved to a certain extent, and the forming quality of the PCB is ensured.

Description

Coreless substrate and packaging method thereof

Technical Field

The invention relates to the technical field of substrate processing, in particular to a coreless substrate and a packaging method thereof.

Background

Coreless technology in package substrates has been developed to meet the increasing trend of lighter, smaller, and better electrical performance in the future for electronic applications. Then, regarding the manufacturing process of 3L coreless substrates, the current manufacturing method is to laminate the whole product to manufacture 6L substrates, and then separate the core layer to achieve the purpose of 3L. Considering the processing procedure of the product of 6L, the coreless core is basically in a liquid tank and cannot be prevented from being infiltrated by liquid medicine. As network systems, high-end servers, and mobile communication devices improve in functionality and performance, the demand for high pin count, data transmission speed, and signal integrity also increases. The infiltration of centreless base plate preparation process liquid medicine can carry out a small amount of bite and corrode or slightly corrode to product copper face circuit, even adopt circuit inspection equipment to inspect centreless base plate, also only discover the problem on the surface, and the slight reaction change of circuit copper inside and various cell body liquid medicines has never been discovered, leads to the performance and the life of product to receive the influence to a certain extent, influences the shaping quality of PCB board.

Disclosure of Invention

Accordingly, it is desirable to provide a coreless substrate and a method for packaging the coreless substrate, which can solve the problem of the corrosion or the corrosion caused by the chemical solution permeating into the copper surface circuit.

The above purpose is realized by the following technical scheme:

a coreless substrate packaging method comprises the following steps:

pasting a film on the substrate;

exposing the substrate;

etching and grooving the metal layer of the substrate to recess the metal layer and form a groove;

pressing a filling piece on the substrate so that the filling piece fills the groove;

and laminating, electroplating and processing the substrate to form the packaging substrate.

In one embodiment, the groove is located at the edge of the substrate or has a preset distance with the edge of the substrate.

In one embodiment, the depth of the recess is less than the thickness of the metal layer.

In one embodiment, the depth of the groove is 1/3-4/5 of the thickness of the metal layer.

In one embodiment, the filler member is a thermoplastic material.

In one embodiment, the filler is a PP prepreg.

In one embodiment, the substrate has the first region and a second region, the first region is located inside the second region, and the exposing the substrate further includes:

managing an exposure area of the substrate;

and exposing the first area, and not exposing the second area, so that an exposed edge of the substrate is formed.

In one embodiment, the width of the second region is 1.5mm to 3.5 mm.

In one embodiment, the coreless substrate packaging method further comprises the steps of:

performing first pretreatment on the substrate before film pasting on the substrate;

and after grooving the substrate, carrying out second pretreatment on the substrate.

A coreless substrate is manufactured by adopting the coreless substrate packaging method with any technical characteristic.

After the technical scheme is adopted, the invention at least has the following technical effects:

the coreless substrate and the packaging method thereof carry out etching and slotting on the substrate, fill the groove formed after the etching and slotting by the filling piece, and form a dam structure to isolate liquid medicine by the filling piece and the groove. The problem of corrosion or bite that the effectual solution current liquid medicine infiltration copper face circuit leads to is corroded. Therefore, the liquid medicine can be prevented from permeating into the coreless substrate, the performance and the service life of the coreless substrate are ensured, the yield of the finished product and the related electrical performance of the finished product are improved to a certain extent, and the forming quality of the PCB is ensured.

Drawings

FIG. 1 is a flow chart illustrating a coreless substrate packaging method according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a substrate after a grooving step;

FIG. 3 is a schematic view of a substrate after a bonding step;

fig. 4 is a schematic top view of the substrate before the exposure step.

Wherein:

100-a substrate;

110-a substrate;

120-a metal layer;

121-a first area;

122-a second region;

130-a groove;

140-a filler.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the coreless substrate and the packaging method thereof according to the present invention are further described in detail by the following embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings). In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Referring to fig. 1 to 3, the present invention provides a method for packaging a coreless substrate. The coreless substrate packaging method is used for packaging the substrate 100 to be packaged so that the substrate 100 forms a coreless substrate. The coreless substrate packaging method can prevent the liquid medicine from permeating into the coreless substrate, ensure the performance and the service life of the coreless substrate, improve the yield of products and the related electrical property of finished products to a certain extent and ensure the molding quality of PCB boards.

In one embodiment, the coreless substrate packaging method comprises the following steps:

pasting a film on the substrate 100;

exposing the substrate 100;

etching and slotting the metal layer 120 of the substrate 100 to recess the metal layer 120 and form a groove 130;

pressing the filling member 140 on the substrate 100, so that the filling member 140 fills the groove 130;

the substrate 100 is laminated, plated, and processed to form the package substrate 100.

It is understood that the substrate 100 includes a substrate 110 and a metal layer 120, and the metal layer 120 is located above the substrate 110. Typically, metal layer 120 is copper.

The substrate 100 is subjected to a film-attaching process, i.e., a film is attached to the metal layer 120 of the substrate 100. The film can protect the metal layer 120 on the substrate 100 to prevent the metal layer 120 from being scratched off during subsequent etching or the like of the substrate 100. After the film attaching step is completed, exposure processing needs to be performed on the substrate 100 after the film attaching. It can be understood that after the exposure treatment of the substrate 100 after the film pasting, the film can be tightly attached to the substrate 100, so as to prevent the metal layer 120 from being bitten off in the subsequent etching process and the like of the substrate 100. The metal layer 120 not exposed may be etched away.

The metal layer 120 of the substrate 100 is then etched open, such that the surface of the metal layer 120 is recessed, which may form a recess 130. At this time, a height difference is formed between the bottom of the groove 130 and the surface of the metal layer 120. It will be appreciated that the recess 130 is of annular configuration. Thus, when the substrate 100 is pressed, the filling member 140 can be pressed on the surface of the substrate 100 and can fill the groove 130. The packing 140 may perform a sealing function. After lamination, the groove 130 and the filling member 140 are tightly combined to form a height difference dam for isolating the chemical solution, so as to prevent the chemical solution from penetrating into the substrate 100 to corrode the metal layer 120 during the subsequent wet treatment of the substrate 100. It is understood that the wet process refers to a process of processing the substrate 100 with chemicals during the packaging process, and is often referred to as a wet process by those skilled in the art, and will not be described herein.

Finally, a series of processes such as lamination, electroplating, and processing are performed on the substrate 100 pressed with the filling member 140, so that the substrate 100 is formed into a coreless substrate. It should be noted that a series of steps of laminating, electroplating, processing and the like are performed on the substrate 100 of the press-fit filling member 140 in the prior art, and are not described herein again. That is, the coreless substrate packaging method of the present invention etches the recess 130 on the substrate 100 based on the conventional coreless substrate packaging process, and the filling member 140 is used to perform a pressing process on the recess 130.

The coreless substrate packaging method of the invention etches and slots the substrate 100, and fills the groove 130 formed after the etching and the slot through the filling piece 140, and the filling piece 140 and the groove 130 form a dam structure to isolate the liquid medicine. The problem of corrosion or bite that the effectual solution current liquid medicine infiltration copper face circuit leads to is corroded. Therefore, the liquid medicine can be prevented from permeating into the coreless substrate, the performance and the service life of the coreless substrate are ensured, the yield of the finished product and the related electrical performance of the finished product are improved to a certain extent, and the forming quality of the PCB is ensured.

In one embodiment, the groove 130 is located at the edge of the substrate 100 or a predetermined distance from the edge of the substrate 100. That is, the groove 130 may be a plate-edge groove, that is, the groove 130 is located at the edge of the substrate 100, and the groove 130 is communicated with the side edge region of the substrate 100, as shown in fig. 2. This facilitates the peeling of the later formed circuit layer structure from the substrate 110 and the resulting finished product. Of course, in other embodiments of the present invention, the groove 130 may have a certain distance from the edge of the substrate 100.

It should be noted that, no matter the groove 130 is located at the edge of the substrate 100 or a preset distance exists between the groove 130 and the edge of the substrate 100, after the filling member 140 fills the groove 130, the metal layer 120 and the filling member 140 can be tightly combined to ensure the sealing performance of the substrate 100, so as to prevent the liquid medicine from permeating into the substrate 100 during the wet treatment process of the substrate 100, further prevent the liquid medicine from biting or corroding the metal layer 120 of the substrate 100, ensure the performance and the service life of the coreless substrate, improve the yield of products and the related electrical performance of finished products to a certain extent, and ensure the molding quality of the PCB board.

In one embodiment, the depth of the recess 130 is less than the thickness of the metal layer 120. That is, during the etching process of the substrate 100, the metal layer 120 may remain at the bottom of the groove 130. This facilitates the peeling of the later formed circuit layer structure from the substrate 110 and the resulting finished product. After the filling member 140 is filled into the groove 130, the groove 130 can be tightly combined with the filling member 140, thereby ensuring the sealing effect and preventing the liquid medicine from permeating.

Furthermore, the depth of the groove 130 is 1/3-4/5 of the thickness of the metal layer 120. The depth range of the groove 130 can facilitate the later formed circuit layer structure to be stripped from the substrate 110, and can also ensure the sealing performance of the filling member 140 after filling.

Of course, in other embodiments of the present invention, the depth of the groove 130 may be equal to the thickness of the metal layer 120. That is, after the substrate 100 is provided with the groove 130, the base material 110 is exposed at the bottom of the groove 130, and the metal layer 120 is not present. After the filling member 140 is pressed on the substrate 100, the filling member 140 can be tightly combined with the substrate 110, thereby ensuring the sealing effect.

In one embodiment, the filler element 140 is a thermoplastic material. This ensures that the filling member 140 flows into the groove 130 to be filled during the pressing. Further, the filler 140 is a PP (Polypropylene) prepreg. During pressing, the groove 130 subjected to etching treatment is filled with the PP prepreg, so that the PP + metal layer 120 forms a dam isolation combination effect, and liquid medicine is prevented from permeating.

Referring to fig. 1 and 4, in an embodiment, the substrate 100 has a first region 121 and a second region 122, the first region 121 is located inside the second region 122, and the exposing the substrate 100 further includes:

managing an exposure area of the substrate 100;

the first region 121 is exposed to light, and the second region 122 is not exposed to light, so that an exposed margin is formed on the substrate 100.

It is understood that the first region 121 of the substrate 100 refers to a central region of the substrate 100 and the second region 122 of the substrate 100 refers to an edge region of the substrate 100. The first region 121 of the substrate 100 may be exposed such that the metal layer 120 in the first region 121 of the substrate 100 is in close contact with the film. Since the second region 122 of the substrate 100 is not exposed, an exposed edge can be formed, which facilitates the etching operation of the metal layer 120. Specifically, when the substrate 100 is etched, the metal layer 120 in the first region 121 of the substrate 100 is not etched, and the metal layer 120 in the second region 122 is etched. At this time, the etched metal layer 120 is recessed with respect to the metal layer 120 that is not etched to form a groove 130. After the groove 130 is formed, the filling member 140 may be filled into the groove 130, so that the filling member 140 and the metal layer 120 form a dam structure, thereby ensuring a sealing effect and preventing liquid medicine from permeating.

Further, the width of the second region 122 is 1.5mm to 3.5 mm. That is, the width from the groove 130 to the edge of the substrate 100 is 1.5mm to 3.5 mm. That is, in fig. 4, the width of the groove 130 in the left-right direction is 1.5mm to 3.5 mm. Preferably, the width of the groove 130 is 2.5 mm.

Referring to fig. 1, in an embodiment, before the substrate 100 is slotted, the coreless substrate packaging method further includes the following steps:

before the substrate 100 is subjected to film attachment, the substrate 100 is subjected to a first pretreatment.

It will be appreciated that the substrate 100 is first pre-processed, i.e., the substrate 100 is first cleaned. Thus, the substrate 100 can be ensured to be clean, and the film can be attached conveniently. Illustratively, the substrate 100 is only acid washed, but not microetched, during the first cleaning. The acid cleaning is used to clean the surface of the substrate 100, which is beneficial to film adhesion and prevents the metal layer 120 from sinking due to the impurities attached to the effective area of the substrate 100 during the manufacturing process.

In one embodiment, the coreless substrate packaging method further includes:

after the substrate 100 is grooved, the substrate 100 is subjected to a second pretreatment.

It will be appreciated that the substrate 100 is subjected to a second pretreatment, i.e., the substrate 100 is subjected to a second cleaning. This can clean the edge of the substrate 100 from contamination and prevent the metal layer 120 from being depressed by foreign materials after lamination.

The method for packaging the coreless substrate 100 of the invention can etch the substrate 100, thus, the filling member 140 fills the groove 130 during lamination, and the characteristic of a dam formed by the filling member 140 and the metal layer 120 is utilized, thereby achieving the manufacturing scheme of preventing the liquid medicine from permeating. It should be noted that, in the method, only the structure of the recess 130 etched on the substrate 100 by photoimaging is added on the basis of the current process for manufacturing the coreless substrate, and the existing equipment can be used without adding new equipment investment. Moreover, the coreless substrate is manufactured by adopting a coreless substrate packaging method, so that the yield of products and the related electrical property of the finished products can be improved to a certain extent.

The invention also provides a coreless substrate, which is processed by adopting the coreless substrate packaging method in any embodiment.

Because the coreless substrate is processed by adopting the coreless substrate packaging method, the problem that a copper surface circuit is corroded or bitten by the fact that liquid medicine permeates into the substrate 100 in a wet process is solved, the performance and the service life of the coreless substrate are guaranteed, the yield of products and the related electrical performance of finished products are improved to a certain extent, and the forming quality of the PCB is guaranteed.

The technical features of the embodiments described above can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (9)

1. A coreless substrate packaging method is characterized by comprising the following steps:

pasting a film on the substrate;

exposing the substrate, wherein the substrate comprises a base material and a metal layer;

etching and grooving the metal layer of the substrate to recess the metal layer and form a groove;

pressing a filling piece on the substrate so that the filling piece fills the groove, and the groove and the filling piece form a height difference dam to seal the substrate, so that a circuit layer structure formed at a later stage can be conveniently stripped from the base material;

laminating, electroplating and processing the substrate to form a packaging substrate;

the depth of the groove is smaller than the thickness of the metal layer.

2. The coreless substrate packaging method of claim 1, wherein the recess is at an edge of the substrate or at a predetermined distance from the edge of the substrate.

3. The coreless substrate packaging method of claim 1, wherein the depth of the recess is 1/3 to 4/5 of the thickness of the metal layer.

4. The coreless substrate packaging method of any one of claims 1 to 3, wherein the filler is a thermoplastic material.

5. The coreless substrate packaging method of claim 4, wherein the filler is a PP prepreg.

6. The coreless substrate packaging method of any one of claims 1 to 3, wherein the substrate has a first region and a second region, the first region being located inside the second region, the exposing the substrate further comprising:

managing an exposure area of the substrate;

and exposing the first area, and not exposing the second area, so that an exposed edge of the substrate is formed.

7. The coreless substrate packaging method of claim 6, wherein the width of the second region is 1.5mm to 3.5 mm.

8. The coreless substrate packaging method of any one of claims 1 to 3, further comprising:

performing first pretreatment on the substrate before film pasting on the substrate;

and after grooving the substrate, carrying out second pretreatment on the substrate.

9. A coreless substrate, wherein the coreless substrate is processed by the coreless substrate packaging method of any one of claims 1 to 8.

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