Multi-order HDI with laser hole overlaid on SLOT hole and preparation method of multi-order HDI

Abstract

The invention discloses a multi-order HDI (High Density Interconnection) with a laser hole superposed on an SLOT (Single Line Of Third) hole and a preparation method thereof, and belongs to the technical field of HDI preparation. The method comprises the following steps: drilling the SLOT hole in a daughter board; a copper block is plugged into the SLOT hole; the plurality of prepregs and the M daughter boards are used for completing first-time pressing to obtain a first-time pressing board; first-order laser holes are drilled in the two ends of the SLOT hole of the first-time laminated plate, then hole filling, electroplating and pattern transferring are carried out, and first-order HDI is obtained; after a layer of daughter board is pressed on the upper portion and the lower portion of the n-order HDI respectively, (n + 1)-order laser holes are drilled in the two ends of the n-order laser holes, then hole filling, electroplating and pattern transferring are conducted, (n + 1)-order HDI is obtained, the step is repeated according to the sequence that the value of n ranges from 1 to N-1 till the N-order HDI is obtained, and n is increased by 1 every time; the copper block is used, the operation process is simple, the SLOT hole electroplating process and the resin plug and cap electroplating process are omitted, and the yield and the production period are guaranteed.

Description

Technical Field

[0001] The invention relates to a multi-stage HDI with a laser hole superimposed on a SLOT hole and a preparation method thereof, belonging to the technical field of HDI preparation. Background Art

[0002] As the demand for electronic consumer products in the world market increases, the functions of electronic products are becoming more and more complex, the performance is becoming more and more superior, and the size is becoming smaller and smaller, so the requirements for PCB boards are getting higher and higher. Recently, this is particularly evident in the widespread application of HDI boards, which are used in navigation, medical treatment, transportation, remote calls, communication equipment and other fields. With the wide application of small-size packaged portable electronic devices and high-density interconnection, the requirements for such HDI boards are getting higher and higher. As the first laminated board becomes thicker and thicker, the number of laser superimposed layers increases, and SLOT holes (slot holes) need to be superimposed on laser holes to transfer POWER (power).

[0003] The traditional approach is to directly superimpose laser holes on the SLOT holes, which will result in the following problems: when the sub-board is pressed together for the first time, the board becomes thicker and thicker, and the hole wall copper of the SLOT hole is thicker. Due to the electroplating capacity problem and the surface copper routing requirements, an additional hole copper electroplating process needs to be added, which is a long process and increases the cost; the SLOT hole must be filled with resin after electroplating. If the resin is not fully filled, the defective rate is high and rework and repair are required; the cap must be electroplated after the resin plug, and there is a risk of cap subsidence and voids; the reliability of multi-stage laser holes is difficult to control due to the risk of resin plugging and capping after superposition; in summary, the yield rate of the produced multi-stage HDI is low and the delivery cycle is long. Summary of the invention

[0004] The object of the present invention is to provide a multi-stage HDI with laser holes superimposed on SLOT holes and a preparation method thereof, so as to solve the problems of low yield and long delivery cycle existing in the prior art.

[0005] To achieve the above objectives, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides a method for preparing a multi-stage HDI by superimposing a laser hole on a SLOT hole, comprising: Drill SLOT holes on the daughter board; Insert the copper block into the SLOT hole; A first pressing is performed using a plurality of prepregs and M sub-boards to obtain a first pressing board; Drill 1st-order laser holes at both ends of the SLOT holes of the first laminated board, then perform hole filling, electroplating and pattern transfer to obtain 1st-order HDI; After laminating one layer of sub-board on the upper and lower sides of the n-order HDI, drill n+1-order laser holes at both ends of the n-order laser holes, and then fill the holes, electroplate and transfer the patterns to obtain the n+1-order HDI. Repeat this step in the order of n from 1 to N-1 until the N-order HDI is obtained, and n increases by 1 each time. The N-order HDI is an N+M+N layer structure.

[0006] Furthermore, the size of the SLOT hole is: 2.4~2.6mm in length and 2.4~2.6mm in width.

[0007] Furthermore, the copper block is a bare copper block.

[0008] Furthermore, during the first lamination process, the glue produced by the prepreg during the lamination process flows into the gap between the copper block and the SLOT hole, and the copper block is fixed in the SLOT hole by the glue flow.

[0009] Further, the first lamination using a plurality of prepregs and M sub-boards includes: The stacking is completed according to the standard of one layer of sub-board and one layer of prepreg, with the uppermost layer and the lowermost layer both being sub-boards, and then pressed once to obtain the first pressed board.

[0010] Furthermore, the thickness of the first pressed plate is 2.8-3.2 mm.

[0011] Furthermore, the hole filling is resin plugging.

[0012] Furthermore, the electroplating is cap electroplating.

[0013] In a second aspect, the present invention provides a multi-stage HDI with laser holes superimposed on SLOT holes, which is prepared by any method described in the first aspect.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: The present invention provides a multi-level HDI with laser holes superimposed on SLOT holes and a preparation method thereof. The method of inserting a copper block into the SLOT hole and then superimposing the multi-level laser holes is adopted, thereby saving the copper electroplating and cover hole thinning processes in the SLOT holes, saving the SLOT hole resin plugging process, saving the cover cap electroplating process after the SLOT hole resin plugging, avoiding the SLOT hole resin plugging hole sinking and scrapping, and avoiding the reliability risk of the multi-level laser holes. Generally speaking, the process time and cost are saved, and the multi-level HDI production is smoother and the yield rate is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of a method for preparing a multi-stage HDI with laser holes superimposed on SLOT holes corresponding to Example 1 of the present invention; Figure 2It is a structural schematic diagram of a finished product obtained by a method for preparing a multi-stage HDI with laser holes superimposed on SLOT holes provided in Example 2 of the present invention; Figure 3 It is a schematic diagram of the structure of a multi-stage HDI made by traditional methods; Figure 4 It is a flow chart of a method for preparing a multi-stage HDI with laser holes superimposed on SLOT holes corresponding to Example 2 of the present invention; Figure 5 is a schematic diagram of step 1 in embodiment 2 of the present invention; Figure 6 is a schematic diagram of step 2 in embodiment 2 of the present invention; Figure 7 is a schematic diagram of step 3 in embodiment 2 of the present invention; Figure 8 is a schematic diagram of step 4 in embodiment 2 of the present invention; Fig. 9 It is a schematic diagram of step 5 in Example 2 of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention.

[0017] Example 1.

[0018] like Figure 1 As shown, the present invention provides a multi-stage HDI preparation method of superimposing a laser hole on a SLOT hole, comprising: Drill SLOT holes on the daughter board; Insert the copper block into the SLOT hole; A first pressing is performed using a plurality of prepregs and M sub-boards to obtain a first pressing board; Drill 1st-order laser holes at both ends of the SLOT holes of the first laminated board, then perform hole filling, electroplating and pattern transfer to obtain 1st-order HDI; After laminating one layer of sub-board on the upper and lower sides of the n-order HDI, drill n+1-order laser holes at both ends of the n-order laser holes, and then fill the holes, electroplate and transfer the patterns to obtain the n+1-order HDI. Repeat this step in the order of n from 1 to N-1 until the N-order HDI is obtained, and n increases by 1 each time. The N-order HDI is an N+M+N layer structure.

[0019] The present invention ensures that the power transmission requirements are met by using copper blocks, and has the advantages of simple operation process and no defects such as sinking. The most important function is to save the SLOT hole electroplating and resin plug and cap electroplating processes, thereby ensuring the overall yield and production cycle of multi-stage HDI products.

[0020] Example 2.

[0021] like Figure 4 As shown, the present invention provides a multi-stage HDI preparation method of superimposing a laser hole on a SLOT hole, comprising: Step 1: Figure 5 As shown, take M daughter boards, drill SLOT holes on the daughter boards, the size of the SLOT holes is 2.5mm*2.5mm (length*width), and then transfer them to the press-fit plug copper block area.

[0022] Step 2: If Figure 6 As shown, take the copper block and insert it into the SLOT hole drilled in step 1.

[0023] Name of copper block: plain copper block; Purity: The purity of copper block is one of the important indicators to measure its quality. High-purity copper blocks usually have better conductivity, thermal conductivity and corrosion resistance; Manufacturing process: The refinement of the manufacturing process will also affect the quality of the copper block. Advanced manufacturing technology can ensure the dimensional accuracy, surface finish and uniformity of the internal structure of the copper block; Physical properties: The physical properties of copper blocks, such as density, hardness, tensile strength, etc., are also important aspects of evaluating their quality. These properties directly affect the performance of the copper block in subsequent processing and use.

[0024] Step 3: If Figure 7 As shown, after the SLOT holes are plugged with copper blocks, M daughter boards and a corresponding number of prepregs are stacked and pressed for the first time, and the copper blocks are fixed in the board by the flow of glue from the prepregs.

[0025] Step 4: Figure 8 As shown, first-order laser holes are drilled at both ends of the SLOT hole, and then the holes are filled, electroplated and pattern transferred to obtain a first-order HDI.

[0026] Step 5: Fig. 9 As shown, steps 3 and 4 are repeated N times to obtain a multi-order HDI of N+M+N structure.

[0027] The structure of the finished product finally obtained by this embodiment is as follows Figure 2 As shown, L1 to L24 represent the 1st to 24th layers, copper represents copper, Plating represents plating, PP represents prepreg, and PTH1-24 represents plated through holes (from the 1st to the 24th layer).

[0028] The structure of the finished product obtained by traditional methods is as follows Figure 3 shown.

[0029] from Figure 2 and Figure 3It can be clearly seen from the comparison that the present invention adopts the method of inserting a copper block into the SLOT hole and then superimposing multi-stage laser holes, which saves the copper electroplating and cover hole thinning processes in the SLOT hole, saves the SLOT hole resin plugging process, saves the cap electroplating process after the SLOT hole resin plugging, avoids the SLOT hole resin plugging hole sinking and defective scrapping, avoids the reliability risk of multi-stage laser holes, and generally speaking, saves process time and cost, makes multi-stage HDI production smoother, and has a higher yield rate.

Claims

1. A method for preparing a multi-stage HDI by superimposing a laser hole on a SLOT hole, characterized in that: include: Drill SLOT holes on the daughter board; Insert the copper block into the SLOT hole; A first pressing is performed using a plurality of prepregs and M sub-boards to obtain a first pressing board; Drill 1st-order laser holes at both ends of the SLOT holes of the first laminated board, then perform hole filling, electroplating and pattern transfer to obtain 1st-order HDI; After laminating one layer of sub-board on the upper and lower sides of the n-order HDI, drill n+1-order laser holes at both ends of the n-order laser holes, and then fill the holes, electroplate and transfer the patterns to obtain the n+1-order HDI. Repeat this step in the order of n from 1 to N-1 until the N-order HDI is obtained, and n increases by 1 each time. The N-order HDI is an N+M+N layer structure.

2. The method for preparing a multi-stage HDI by superimposing a laser hole on a SLOT hole according to claim 1, characterized in that: The size of the SLOT hole is: 2.4~2.6mm in length and 2.4~2.6mm in width.

3. The method for preparing a multi-stage HDI by superimposing a laser hole on a SLOT hole according to claim 1, characterized in that: The copper block is a bare copper block.

4. The method for preparing a multi-stage HDI by superimposing a laser hole on a SLOT hole according to claim 1, characterized in that: During the first lamination process, the glue produced by the prepreg during the lamination process flows into the gap between the copper block and the SLOT hole, and the copper block is fixed in the SLOT hole by the glue.

5. The method for preparing a multi-stage HDI by superimposing a laser hole on a SLOT hole according to claim 1, characterized in that: The method of using a plurality of prepregs and M sub-boards to complete the first lamination includes: The stacking is completed according to the standard of one layer of sub-board and one layer of prepreg, with the uppermost layer and the lowermost layer both being sub-boards, and then pressed once to obtain the first pressed board.

6. The method for preparing a multi-stage HDI by superimposing a laser hole on a SLOT hole according to claim 1, characterized in that: The thickness of the first pressed plate is 2.8-3.2 mm.

7. The method for preparing a multi-stage HDI by superimposing a laser hole on a SLOT hole according to claim 1, characterized in that: The filling holes are resin plugging holes.

8. The method for preparing a multi-stage HDI by superimposing a laser hole on a SLOT hole according to claim 1, characterized in that: The electroplating is cap electroplating.

9. A multi-stage HDI with laser holes superimposed on SLOT holes, characterized in that: Prepared by the method according to any one of claims 1 to 8.

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