Packaging substrate processing method and packaging substrate

Abstract

The embodiment of the invention provides a packaging substrate processing method and a packaging substrate, and the method comprises the steps: carrying out the drilling of the packaging substrate, so as to form a tool hole; preparing a solder mask layer on the packaging substrate, wherein the solder mask layer is accumulated in the tool hole to form an accumulation material; and performing laser ablation on the tool hole to remove the accumulated material in the tool hole. According to the packaging substrate processing method provided by the embodiment of the invention, the required tool hole is drilled before the solder mask layer is prepared on the packaging substrate, and the accumulated material in the tool hole is ablated and removed after the solder mask layer is prepared, so that the required tool hole is obtained, the packaging substrate does not need to be subjected to expansion and contraction classification and then is positioned by using a pin for drilling, and the processing efficiency of the packaging substrate is improved. The machining precision of the tool hole in the packaging substrate can be improved, laser ablation is non-contact machining, accumulated materials in the tool hole are ablated at a fixed point, secondary damage to the tool hole is avoided, and the quality problems of hole opening damage, burrs and the like are avoided.

Description

Technical Field

[0001] The present application relates to the technical field of packaging substrate processing, and in particular to a packaging substrate processing method and a packaging substrate. Background Art

[0002] The tool holes on the package substrate are key mechanical functional elements in its manufacturing and assembly. Tool holes are mainly used for mechanical fixation, electrical connection, process benchmark and function expansion, and are of irreplaceable significance in improving the assembly efficiency, structural stability and long-term reliability of the package substrate.

[0003] Among the current related technologies in the industry, the processing of tool holes in package substrates with a finished thickness of more than 0.35mm is carried out by using a mechanical drill to perform secondary drilling to produce the required tool holes after the package substrate has completed the solder mask process. This method requires the package substrate to be fully measured for expansion and contraction dimensions before the second mechanical drilling, and then processed in different expansion and contraction intervals. The workload of expansion and contraction classification is large, the use of pins for secondary positioning drilling has low accuracy, and drilling of multiple pieces in a stack is prone to quality problems such as tool hole damage, burrs, and cutting edges. Summary of the Invention

[0004] The embodiments of the present application provide a packaging substrate processing method and a packaging substrate, which can improve the processing accuracy of tool holes on the packaging substrate without causing secondary damage to the tool holes, and without quality problems such as hole damage, burrs, etc.

[0005] The present invention provides a method for processing a package substrate, including: drilling the package substrate to form a tool hole; preparing a solder resist layer on the package substrate, wherein the solder resist layer accumulates in the tool hole to form an accumulation material; The tool hole is laser ablated to remove accumulated material within the tool hole.

[0006] In some embodiments, the laser ablating the tool hole to remove accumulated material in the tool hole comprises: Laser ablation is performed along a straight path from a first point on the tool hole wall toward a second point on the tool hole wall, wherein a straight line connecting the first point and the second point passes through the axis of the tool hole, so as to cut the accumulated material in the tool hole into at least two parts.

[0007] In some embodiments, the first point and the second point are both spaced apart, and the laser ablation is performed along a straight path from the first point on the tool hole wall toward the second point on the tool hole wall, comprising: Laser ablation is performed multiple times along a straight path from different first points on the tool hole wall toward corresponding second points on the tool hole wall to cut the accumulated material in the tool hole into multiple parts.

[0008] In some embodiments, the first points and the second points are each four at intervals, so as to cut the accumulated material in the tool hole into eight parts.

[0009] In some embodiments, after laser ablation is performed along a straight path from a first point on the tool hole wall toward a second point on the tool hole wall, the method further comprises: Laser ablation is performed along a circular closed path in the circumferential direction of the wall of the tool hole, so that at least two parts cut from the accumulated material are separated from the wall of the tool hole.

[0010] In some embodiments, the package substrate includes a first surface and a second surface opposite to each other, the tool hole penetrates the first surface and the second surface, and the laser ablation of the tool hole to remove accumulated material in the tool hole includes: performing a first laser ablation on the tool hole from the first surface; Turning over the packaging substrate; performing a second laser ablation on the tool hole from the second surface; The sum of the depth of the first laser ablation and the depth of the second laser ablation is greater than or equal to the thickness of the accumulated material.

[0011] In some embodiments, the depth of the first laser ablation is 1 / 3 to 1 / 2 of the thickness of the accumulated material.

[0012] In some embodiments, after laser ablating the tool hole to remove the accumulated material in the tool hole, the method further comprises: A suction device is used to absorb the accumulated material removed from the tool hole.

[0013] In some embodiments, before preparing the solder resist layer on the package substrate, the method further includes: Performing copper electroplating on the packaging substrate to form a conductive layer on the inner wall of the tool hole; The packaging substrate is developed and etched to form a circuit pattern, and the conductive layer on the inner wall of the tool hole is removed.

[0014] An embodiment of the present application further provides a packaging substrate, which is obtained by processing the packaging substrate processing method described in any one of the above embodiments.

[0015] The packaging substrate processing method of the embodiment of the present application obtains the required tool holes by drilling the required tool holes before preparing the solder mask layer on the packaging substrate, and ablating and removing the accumulated materials in the tool holes after preparing the solder mask layer. There is no need to classify the packaging substrate for expansion and contraction and then use pins to locate and drill the holes. The processing accuracy of the tool holes on the packaging substrate can be improved. Laser ablation is a non-contact processing method that ablates the accumulated materials in the tool holes at a fixed point, and will not cause secondary damage to the tool holes. There are no quality problems such as hole damage, burrs, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0017] Figure 1 Schematic diagram of the process of the packaging substrate processing method according to an embodiment of the present application.

[0018] Figure 2 This is a flow chart of performing laser ablation on a tool hole to remove accumulated material in the tool hole in a packaging substrate processing method according to an embodiment of the present application.

[0019] Figure 3 Schematic diagram of laser ablation performed along a straight path from a first point toward a second point in a packaging substrate processing method according to an embodiment of the present application.

[0020] Figure 4 This is a schematic diagram of laser ablation performed along a circular closed path in the circumferential direction of the tool hole wall in the packaging substrate processing method according to an embodiment of the present application.

[0021] Figure 5 This is a flow chart of laser ablation of the first and second surfaces of a packaging substrate in a packaging substrate processing method according to an embodiment of the present application.

[0022] Figure 6 Schematic diagram of laser ablation of the first and second surfaces of a packaging substrate in a packaging substrate processing method according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of this application.

[0024] The embodiment of the present application provides a packaging substrate processing method, which can improve the processing accuracy of the tool hole 2 on the packaging substrate 1 without causing secondary damage to the tool hole 2, and there are no quality problems such as hole damage, burrs, etc.

[0025] refer to Figure 1 , Figure 1 Schematic diagram of a process flow of a packaging substrate processing method according to an embodiment of the present application. The packaging substrate processing method includes the following steps: 10. Drilling the package substrate 1 to form a tool hole 2; 20. Prepare a solder resist layer on the package substrate 1, and accumulate the solder resist layer in the tool hole 2 to form an accumulation material 3; 30. Perform laser ablation on the tool hole 2 to remove the accumulated material 3 in the tool hole 2.

[0026] It should be noted that, in the present application, the required tool hole 2 is drilled on the packaging substrate 1 before preparing the solder mask layer on the packaging substrate 1. Since the preparation of the solder mask layer will cause the material (such as ink) in the tool hole 2 to accumulate and become a hole blockage, the laser drill is used to ablate the accumulated material 3 in the tool hole 2 after preparing the solder mask layer to finally obtain the required tool hole 2. The tool hole 2 laser burns the ink using the laser drill CCD to automatically identify the first mechanical drilling target positioning and automatically compensate for expansion and contraction. There is no need to classify expansion and contraction and then use pins to position and drill. The processing accuracy is high (position deviation ±15um). At the same time, laser ablation is a non-contact processing method to ablate the accumulated material 3 in the tool hole 2 at a fixed point. The low-energy laser is used to have a small heat-affected zone, and will not cause secondary damage to the tool hole 2. There are no problems such as hole damage, burrs, and other defects.

[0027] In order to ensure that the accumulated material 3 in the tool hole 2 is effectively removed during the ablation operation without expanding the tool hole 2, in addition to setting a reasonable laser energy, a special laser ablation path needs to be designed to cut the large accumulated material 3 in the tool hole 2 into several small pieces to facilitate the subsequent cleaning of the accumulated material 3. Figures 2 to 4 , Figure 2 This is a flow chart of performing laser ablation on the tool hole 2 to remove the accumulated material 3 in the tool hole 2 in the packaging substrate processing method according to an embodiment of the present application. Figure 3 Schematic diagram of laser ablation along a straight path from a first point 4 to a second point 5 in a packaging substrate processing method according to an embodiment of the present application. Figure 4 This is a schematic diagram of laser ablation along a circular closed path in the circumferential direction of the wall of the tool hole 2 in the packaging substrate processing method according to an embodiment of the present application.

[0028] Among them, Figure 3 As shown, the steps of laser ablation of the tool hole 2 to remove the accumulated material 3 in the tool hole 2 include: 301. Laser ablation is performed along a straight path from a first point 4 on the wall of the tool hole 2 toward a second point 5 on the wall of the tool hole 2, wherein a straight line connecting the first point 4 and the second point 5 passes through the axis of the tool hole 2, so as to cut the accumulated material 3 in the tool hole 2 into at least two parts.

[0029] like Figure 4 As shown, after laser ablation is performed along a straight path from a first point 4 on the wall of the tool hole 2 toward a second point 5 on the wall of the tool hole 2, the step of laser ablation of the tool hole 2 to remove the accumulated material 3 in the tool hole 2 further includes: 302 . Perform laser ablation along a circular closed path in the circumferential direction of the wall of the tool hole 2 , so that at least two parts cut from the accumulated material 3 are separated from the wall of the tool hole 2 .

[0030] It should be noted that when ablating the accumulated material 3 within the tool hole 2, it is first necessary to determine the starting point (first point 4) and the ending point (second point 5) for cutting the accumulated material 3 on the tool hole 2, and to ensure that the straight line connecting the first point 4 and the second point 5 passes through the axis of the tool hole 2. This will allow the accumulated material 3 to be cut more evenly, making it easier to separate the accumulated material 3 from the hole wall during subsequent circumferential ablation of the accumulated material 3, thereby reducing the difficulty of cutting and the risk of residual material. In actual applications, if the tool hole 2 has a small diameter or the accumulated material 3 is easy to clean, one first point 4 and one second point 5 can each be set to divide the accumulated material 3 into two parts. If the tool hole 2 has a large diameter or the accumulated material 3 is difficult to clean, multiple second points 5 and 5 can also be set to divide the accumulated material 3 into multiple parts, facilitating the subsequent cleaning of the accumulated material 3. After the accumulated material 3 is divided (i.e., after laser ablation is performed along the straight path from all the first points 4 toward the second point 5), laser ablation is required along the annular closed path circumferentially of the wall of the tool hole 2 to cut and remove the divided accumulated material 3 from the wall of the tool hole 2 in turn to complete the removal of the accumulated material 3 in the tool hole 2.

[0031] In the actual production process, the coordinate point of laser ablation should be output at an equal distance on the straight line connecting the first point 4 and the second point 5 with the radius of the effective spot formed by the laser beam as the distance, and then circular ablation should be performed along a trajectory with a diameter of the tool hole 2 minus the radius of the effective spot formed by the laser beam to avoid the laser beam ablating the wall of the tool hole 2 and staying as close to the wall of the tool hole 2 as possible to reduce the residue of accumulated material 3.

[0032] In order to more easily separate the accumulated material 3 from the hole wall during circumferential ablation of the accumulated material 3 and reduce the cutting difficulty and residual risk, the accumulated material 3 needs to be divided into multiple smaller and more uniform parts. Figure 3The first point positions 4 and the second point positions 5 are both spaced apart, and the plurality of first point positions 4 and the plurality of second point positions 5 correspond one to one. The step of performing laser ablation along a straight path from the first point position 4 on the wall of the tool hole 2 toward the second point position 5 on the wall of the tool hole 2 includes: Laser ablation is performed multiple times along a straight path from different first points 4 on the wall of the tool hole 2 toward corresponding second points 5 on the wall of the tool hole 2 to cut the accumulated material 3 in the tool hole 2 into multiple parts.

[0033] It can be understood that by performing laser ablation multiple times along a straight path from different first points 4 on the wall of the tool hole 2 toward the corresponding second points 5 on the wall of the tool hole 2, since the straight lines connecting these first points 4 and the second points 5 all pass through the axis of the tool hole 2, the ablated parts are only connected to the wall of the tool hole 2, and no two parts are connected, which makes it easier to separate the accumulated material 3 from the wall during the subsequent circumferential ablation of the accumulated material 3.

[0034] Alternatively, as Figure 3 As shown, the first point positions 4 and the second point positions 5 are both spaced apart by four, so as to cut the accumulated material 3 in the tool hole 2 into eight parts, so as to balance the processing workload and reduce the difficulty and residual risk of circumferential cutting. If the number of the first point positions 4 and the second point positions 5 is small, for example, two first point positions 4 and two second point positions 5 are set, although the processing workload during straight-line cutting is small, the difficulty and residual risk of subsequent circumferential cutting are large; if the number of the first point positions 4 and the second point positions 5 is large, for example, eight first point positions 4 and eight second point positions 5 are set, although the difficulty and residual risk of subsequent circumferential cutting can be further reduced, the processing workload during straight-line cutting may be significantly increased. Therefore, setting the first point positions 4 and the second point positions 5 to four can reduce the difficulty and residual risk of subsequent circumferential cutting to a certain extent without making the processing process too complicated.

[0035] Preferably, if Figure 3 As shown, for the tool hole 2 with a circular or regular polygonal cross-sectional shape, the first point positions 4 and the second point positions 5 are four spaced apart, and the distance between two adjacent first point positions 4 is equal, and the distance between two adjacent second point positions 5 is equal, so that the cutting path is arranged in a "M" shape, so that the accumulated material 3 is divided into eight more uniform parts, so as to further reduce the difficulty and residual risk of circumferential cutting, and facilitate the subsequent cleaning of the cut parts.

[0036] The packaging substrate processing method of the embodiment of the present application obtains the required tool hole 2 by drilling the required tool hole 2 before preparing the solder mask layer on the packaging substrate 1, and ablating and removing the accumulated material 3 in the tool hole 2 after preparing the solder mask layer. There is no need to classify the packaging substrate 1 according to its expansion and contraction and then use pins to locate and drill the hole. This can improve the processing accuracy of the tool hole 2 on the packaging substrate 1. Laser ablation is a non-contact processing method that ablates the accumulated material 3 in the tool hole 2 at a fixed point, and will not cause secondary damage to the tool hole 2. There are no quality problems such as hole damage, burrs, etc.

[0037] For thicker packaging substrates 1 (thickness greater than 0.35mm), when ablating the accumulated material 3 in the tool hole 2 from the front, the tool hole 2 opening is at the laser focus point. The position deviates from the laser focus point as it moves toward the bottom of the hole. The laser energy density decays, resulting in the inability to ablate the accumulated material 3 at the bottom of the hole normally. At this time, if the laser energy is increased, the base material at the tool hole 2 opening will be affected by the high heat and deform, resulting in abnormal product quality. Therefore, this application further proposes a method of using double-sided laser ablation to improve the problem of the thickness of the packaging substrate 1 affecting the laser focus deviation. Figure 5 and Figure 6 , Figure 5 This is a flow chart of laser ablation of the first and second surfaces of the packaging substrate 1 in the packaging substrate processing method according to an embodiment of the present application. Figure 6 Schematic diagram of laser ablation of the first and second surfaces of the package substrate 1 in the package substrate processing method according to an embodiment of the present application, wherein: Figure 6 It is a longitudinal cross-sectional view of the packaging substrate 1. The up and down directions are used to indicate the first and second surfaces of the packaging substrate 1. The upper end surface is the first surface of the packaging substrate 1, and the lower end surface is the second surface of the packaging substrate 1. The dotted line above the tool hole 2 refers to the laser beam boundary for laser ablation of the first surface, and the dotted line below the tool hole 2 refers to the laser beam boundary for laser ablation of the second surface.

[0038] Among them, Figure 6 As shown, the package substrate 1 includes a first surface and a second surface opposite to each other, and a tool hole 2 passes through the first surface and the second surface. The steps of laser ablation of the tool hole 2 to remove the accumulated material 3 in the tool hole 2 include: 303. Perform a first laser ablation on the tool hole 2 from the first surface; 304. Turn over the packaging substrate 1; 305. Perform a second laser ablation on the tool hole 2 from the second surface; The sum of the depth of the first laser ablation and the depth of the second laser ablation is greater than or equal to the thickness of the accumulated material 3 .

[0039] It should be noted that, in order to avoid deformation of the tool hole 2 base material due to high heat caused by increasing the laser energy, it is necessary to perform laser ablation on the accumulated material 3 multiple times, by Figure 6 The tool hole 2 is first laser ablated from the upper side (as shown in FIG. Figure 6 The tool hole 2 is laser ablated for the second time (as shown in the lower side), and the sum of the depth of the first laser ablation and the depth of the second laser ablation is greater than or equal to the thickness of the accumulated material 3, so as to avoid increasing the laser energy and removing the accumulated material 3 from the tool hole 2.

[0040] In some embodiments, the depth of the first laser ablation is 1 / 3 to 1 / 2 of the thickness of the accumulated material 3. It should be noted that if the depth of the first laser ablation is shallow (for example, 1 / 5 of the thickness of the accumulated material 3), in order to completely remove the additive material, the second laser ablation requires greater laser energy, which can easily cause the base material at the opening of the tool hole 2 to be affected by higher heat and deform. Therefore, setting the depth of the first laser ablation to 1 / 3 to 1 / 2 of the thickness of the accumulated material 3 allows both laser ablations to be performed with lower laser energy, reducing the risk of deformation of the base material at the opening of the tool hole 2 due to higher heat.

[0041] In some embodiments, after laser ablation of the tool hole 2 to remove the accumulated material 3 within the tool hole 2, the process further includes: using a suction device to absorb the removed accumulated material 3 within the tool hole 2. This facilitates cleaning the tool hole 2 and prevents the removed accumulated material 3 from accumulating within the tool hole 2. The suction device can be a vacuum device built into the laser drill or an external negative pressure suction device.

[0042] In some embodiments, before preparing the solder resist layer on the package substrate 1, the method further includes: Performing copper electroplating on the package substrate 1 to form a conductive layer on the inner wall of the tool hole 2; The package substrate 1 is developed and etched to form a circuit pattern, and the conductive layer on the inner wall of the tool hole 2 is removed.

[0043] It is understood that the circuit pattern is formed on the package substrate 1 by copper plating and etching, and the conductive layer on the inner wall of the tool hole 2 is removed by etching to facilitate subsequent electrical connections such as component pin connections. Subsequently, a solder mask layer is formed on the package substrate 1, and when the tool hole 2 is laser ablated, the inner wall of the tool hole 2 is free of the conductive layer.

[0044] An embodiment of the present application also provides a packaging substrate, which is obtained by processing the packaging substrate processing method of any of the above embodiments.

[0045] The packaging substrate of the embodiment of the present application is obtained by adopting the above-mentioned substrate processing method. It does not require expansion and contraction classification and then positioning with pins for drilling. The processing accuracy is high (position deviation ±15um). At the same time, laser ablation is a non-contact processing method for ablation of accumulated materials in the tool hole. The low-energy laser has a small heat-affected zone and will not cause secondary damage to the tool hole. There are no problems such as hole damage, burrs, and other defects.

[0046] In the description of this application, it should be understood that terms such as "first" and "second" are only used to distinguish similar objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0047] It should be noted that in the embodiments of the present application, "connection" can be understood as electrical connection, and the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components.

[0048] It should be understood that the terms "thickness," "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0049] The above is a detailed introduction to the packaging substrate processing method and packaging substrate 1 provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only intended to help understand the present application. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concepts of the present application. In summary, the contents of this specification should not be construed as limiting the present application.

Claims

1. A packaging substrate processing method, characterized in that: include: drilling the package substrate to form a tool hole; preparing a solder resist layer on the package substrate, wherein the solder resist layer accumulates in the tool hole to form an accumulation material; The tool hole is laser ablated to remove accumulated material within the tool hole.

2. The packaging substrate processing method according to claim 1, wherein: The laser ablation of the tool hole to remove the accumulated material in the tool hole comprises: Laser ablation is performed along a straight path from a first point on the tool hole wall toward a second point on the tool hole wall, wherein a straight line connecting the first point and the second point passes through the axis of the tool hole, so as to cut the accumulated material in the tool hole into at least two parts.

3. The packaging substrate processing method according to claim 2, wherein: The first point and the second point are both spaced apart, and the laser ablation is performed along a straight path from the first point on the wall of the tool hole toward the second point on the wall of the tool hole, comprising: Laser ablation is performed multiple times along a straight path from different first points on the tool hole wall toward corresponding second points on the tool hole wall to cut the accumulated material in the tool hole into multiple parts.

4. The packaging substrate processing method according to claim 3, wherein: The first points and the second points are both four at intervals, so as to cut the accumulated material in the tool hole into eight parts.

5. The packaging substrate processing method according to claim 2, wherein: After laser ablation is performed along a straight path from a first point on the tool hole wall toward a second point on the tool hole wall, the method further comprises: Laser ablation is performed along a circular closed path in the circumferential direction of the wall of the tool hole, so that at least two parts cut from the accumulated material are separated from the wall of the tool hole.

6. The packaging substrate processing method according to any one of claims 1 to 5, characterized in that: The packaging substrate includes a first surface and a second surface opposite to each other, the tool hole penetrates the first surface and the second surface, and the laser ablation of the tool hole to remove the accumulated material in the tool hole includes: performing a first laser ablation on the tool hole from the first surface; Turning over the packaging substrate; performing a second laser ablation on the tool hole from the second surface; The sum of the depth of the first laser ablation and the depth of the second laser ablation is greater than or equal to the thickness of the accumulated material.

7. The packaging substrate processing method according to claim 6, wherein: The depth of the first laser ablation is 1 / 3 to 1 / 2 of the thickness of the accumulated material.

8. The packaging substrate processing method according to any one of claims 1 to 5, characterized in that: After laser ablation is performed on the tool hole to remove the accumulated material in the tool hole, the method further includes: A suction device is used to absorb the accumulated material removed from the tool hole.

9. The packaging substrate processing method according to any one of claims 1 to 5, characterized in that: Before preparing the solder resist layer on the packaging substrate, the method further includes: Performing copper electroplating on the packaging substrate to form a conductive layer on the inner wall of the tool hole; The packaging substrate is developed and etched to form a circuit pattern, and the conductive layer on the inner wall of the tool hole is removed.

10. A packaging substrate, characterized in that: The packaging substrate is obtained by processing the packaging substrate according to any one of claims 1 to 9.

Images