KR20010027722A - Method of laminating multi-layer printed circuit board - Google Patents

Abstract

PURPOSE: A method of lamination of a multi-layer printed circuit board(PCB) is provided to prevent from occurring operation delay caused by fixing and riveting, reduce operation time, and improve productivity thereby, enables a smooth operation of lamination, and improves impedance characteristics by balanced lamination. CONSTITUTION: In a method of lamination of a multi-layer printed circuit board, multi-layers of a board are laminated sequentially in order of a copper clad laminated(CCL) layer(10) and a prepreg layer(20). Fixing pins(50) hold a laminated board(1) primarily. Cylinders(60) push fixing plates(50) toward the laminated board(1) on both ways vertically. Heaters(70) attached to cylinders(60) operate in temperatures between 200°C and 400°C and frit prepreg layers on touched spots, holding tight the CCL layers(10) thereby.

Description

Method of laminating multi-layer printed circuit board

The present invention relates to a method of laminating a multi-layer printed circuit board, and more particularly, to a multilayer copper clad laminate (hereinafter, referred to as 'CCL') in the manufacture of a multilayer printed circuit board. The present invention relates to a lamination method of a multilayer printed circuit board that can be stacked more easily without using a tool such as a separate pin or rivet.

In general, a multilayer printed circuit board having a multi-layered printed circuit board has been developed to mount them on a surface according to the miniaturization and integration of electronic components. A multilayer circuit board is manufactured through a very complicated process. Even during the manufacturing process of the multilayer printed circuit board, the laminating process is necessarily accompanied in manufacturing the substrate.

In the conventional stacking method of the multilayered printed circuit board, a pin is mainly used, which is illustrated in FIG. 1.

That is, as shown in Figure 1, based on the four pins (132) installed on the laminated plate 132 of about 8mm thickness through the pretreatment process, the cushion paper 140 and Put the SUS plate (150) one by one in sequence, and the copper foil laminated plate (hereinafter referred to as 'CCL') prepreg and the copper foil on both sides of the desired layer in the pre-lamination operation That is, the multilayer circuit board 100 in which the inner layer circuit (not shown) is formed is alternately stacked, and then the stainless plate 150 and the cushion paper 140 are placed on the upper part of the printed circuit board 100 again and the uppermost part is The stacking operation of the multilayer printed circuit board 100 was performed by placing the upper cover 160.

At this time, the multilayer printed circuit board 100 is fixed as a fixing pin 132 up to approximately 12 sheets, and heat-pressurized in a state in which it is placed on the base 120 at the lower side, thereby printing a plurality of printed circuit boards 100 at a time. Laminated.

However, in the conventional lamination method of the substrate by the pin method, a lot of detailed processes are involved, and in particular, the fixing pin 132 is used until the completion of the lamination, and the multilayer printing is caused by the minute flow generated by the fixing pin 132. Insulation distance deviation and thickness deviation of the circuit board 100 are easily generated, and thus, complicated facilities are additionally required due to the fixed state of the fixing pin 132, which increases work time and costs. There were several problems such as being.

On the other hand, there is known another method of laminating a printed circuit board of the riveting method for solving the problem by the above-described fixed pin method, which is shown in FIG.

That is, as shown in FIG. 2, after the preflag 212 and the CCL 210 are sequentially stacked, the multi-layer substrate 200 is riveted to be preliminarily fixed with the rivets 220, and then the temporary substrate 200 is temporarily fixed. ) Is placed in the carrier plate 230, and then heated and pressurized to stack the multilayer printed circuit board.

However, in the conventional method of laminating a multilayer board by the riveting method as described above, the substrate lamination process is performed by using a rivet instead of the lamination process by the conventional pin method, which is required by the conventional pin method. No additional equipment is required, but as with the conventional pin fixing method, a considerable amount of rivets are needed to increase the manufacturing cost, and especially when the rivet fixing is not precise as in the fixing pin method, the insulation thickness deviation of the rivet stepped portion This impairs the impedance of the multilayer board and delays the lamination of the entire multilayer board due to the removal of the used rivets.

In addition, in the case of laminating multilayer boards for Rambus used in high speed circuit transmission systems, which are currently increasing in use, especially insulation distance deviations and thickness deviations occur severely, resulting in poor impedance, which in turn lowers the reliability of substrate products. There were problems such as.

The present invention has been made in order to improve the various conventional problems as described above, the object of the present invention is to simply melt the pre-flags stacked in the stacking operation of the multi-layer printed circuit board to pre-fix and then perform the entire pressing operation, The present invention provides a method for manufacturing a multilayer printed circuit board, in which overall productivity is further improved by preventing work time delay or insulation distance deviation, thickness variation, and cost increase due to a fixing pin or rivet.

In addition, another object of the present invention is to provide a method for laminating a multilayer printed circuit board, which facilitates a multilayer printed circuit board stacking operation by simply blocking as a release sheet that the pre-flag is fused to the heater rod during preliminary fixing operation. It's there.

On the other hand, another object of the present invention, in particular, the multi-layer printed circuit to improve the impedance characteristics by enabling a uniform insulation distance and thickness stacking in the stacking operation of the Rambus substrate used in a high-speed circuit transmission system that is a rambus system (rambus system) The present invention provides a method for laminating a substrate.

1 is a schematic perspective view showing a substrate stacking structure of a conventional fixing pin method

Figure 2 is a schematic diagram showing another laminated structure of the substrate using a conventional rivet

Figure 3 is a block diagram showing a method of laminating a substrate according to the present invention

Figure 4 is a block diagram showing another stacking method of the present invention substrate

5 (a) and 5 (b) are cross-sectional configuration diagrams showing a laminated state of a general substrate and another Rambus substrate;

Explanation of symbols on the main parts of the drawings

1 .... multilayer board 1 '.... other multilayer boards

10 ... copper clad laminate (CCL) 20 .... insulation layer (preflag)

22 ... copper foil 30 ...

40 .... Release sheet 60 .... Cylinder

70 .... Heating means

The present invention as a technical means for achieving the above object, the pre-lamination step of arranging one or more pre-flags and multi-layer CCL sequentially, and then temporarily fixing them with a fixing pin to prepare a laminated substrate;

Preliminarily fixing the laminated substrate by applying heat for a predetermined time as a heating means for moving up and down as a cylinder to the upper and lower sides of the laminated substrate; And,

Removing the fixing pins of the preliminarily fixed laminated substrates, and then stacking the substrates by pressurizing them by heat and pressure; By providing a method of laminating a multilayer printed circuit board configured as.

In addition, the pre-lamination step of arranging one or more insulating layers and CCL sequentially, and then temporarily fixing them with a fixing pin to prepare a laminated substrate;

Placing a release sheet on the upper and lower sides of the laminated substrate, and preliminarily fixing the laminated substrate by applying heat at a constant temperature for a predetermined time with a heater rod moving up and down as a cylinder at a plurality of points on the surface thereof; And,

After removing the release sheet and the fixing pin of the pre-fixed laminated substrate, heat pressing to press the substrate laminating step; By providing a method of laminating a multilayer printed circuit board configured as.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, as shown in FIGS. 3 and 5A, the multilayer printed circuit board 1 sequentially accumulates the CCL 10 having copper foils attached to both sides of the resin substrate and the preflag 20 serving as an insulating layer therebetween. A laminated substrate 1 is temporarily fixed as a fixing pin 30. The copper foil of the CCL 10 is a inner layer circuit through a peeling process such as normal etching and etching, and the fixing pin 30 is As will be described in detail below, it is not used continuously from the beginning to the completion of lamination like the conventional fixing pin method, but since it is temporarily fixed and then removed when crimping after preliminary fixing operation, it is compared with maintaining the fixed state using only the conventional fixing pin. It is easy to fix and remove the fixing pin.

Next, as shown in FIG. 3, after the fixing plate 50 is fixed to the upper and lower layers of the laminated substrate 1 preliminarily fixed as the fixing pin 30, the upper and lower sides of the multilayer board 1 are fixed to the upper and lower sides through the fixing plate 50. When the installed cylinder 60 is lowered, the heating means installed on the lower side of the cylinder 60, that is, the heater rod 70 is in contact with a plurality of points on the upper and lower surfaces of the laminated substrate 1, if necessary, the laminated substrate The upper and lower surfaces of (1) are in contact with the total 2-20 points.

At this time, when the heater rod 70 is operated and heat is applied at a temperature of about 200 to 400 ° C. for a predetermined time, a part of the preflag 20 of the laminated substrate 1 is partially free, that is, at a portion of the contact point. When the flag 20 is melted and eventually the multi-layer CCL 10 is preliminarily fixed, if the heating temperature is less than 200 ° C. or greater than 400 ° C., the molten state of the preflag is not completely made between layers, or On the contrary, the fusion becomes excessive.

Next, the heating temperature and the heating time of the heater rod 70 is different according to the thickness of the laminated substrate 1, that is, the final thickness, which will be described as Table 1 below, and Table 1 above 6 layers. Figures for multilayer substrates.

division Time (sec) Data for multi-layer boards with 6 layers or more, and multi-layer boards with 4 layers or less are 18-22 sec. 0.55t or less 23-27 200-400 0.56t-1.00t 28-32 " 1.01t-1.30t 32-37 " 1.31t-1.60t 38-42 " 1.61t-2.00t 45-55 " 2.01t-2.40 55-65 " 2.41t-3.20t 85-95 " 3.21t-4.00t 115-125 " 4.01t-5.00t 135-145 " 5.01t-6.00t 155-165 "

On the other hand, although the upper and lower sides of the laminated substrate 1 which are non-laminated in the same manner as described above are not described in detail, the copper foil 22 serving as the outer layer circuit of the multilayer printed circuit board 1 through a normal peeling process. When the laminate is heated and pressurized by a press, the pre-fixed laminated substrate 1 is completely compressed and laminated into one multilayer printed circuit board product.

And, since the fixing pin 30 for preliminary fixing the laminated substrate 1 is removed from the laminated substrate 1 after the pre-lamination operation by heating before the crimping operation, that is to perform a separate laminated substrate fixing operation It is easy to fix and remove the fixing pin, so that the lamination process of the multilayer printed circuit board can be performed extremely precisely. In particular, the interlayer insulation distance and thickness of the laminated substrate 1 are kept constant, which in turn The low dielectric constant of the substrate is ensured to maintain a constant impedance characteristic of the substrate, which is to improve the impedance characteristic of a multilayer substrate for rambus, which is used in a high-speed circuit transmission system, which is a Rambus system included in the multilayer substrate 1.

Meanwhile, FIG. 5B shows another Rambus multilayer substrate 1 'having a different lamination structure. The other Rambus substrate 1' has a CCL 10 'and 10 " It is a structure in which only a lamination is made, and thus, a separate preflag layer for joining copper foils forming an outer layer circuit is not necessary, and a multilayer inner layer CCL (in which the copper foils on both sides become an inner layer circuit 10a 'through a normal peeling process) 10 '), one or more layers of preflags 20, and an outer layer CCL 10 " having an inner layer circuit 10a " as an outer layer, are preliminarily fixed as the fixing pins 30, as shown in FIG. After being heated as a heater rod 70 and pre-laminated, the fixing pin 30 is removed and pressurized to perform a lamination operation, wherein the outer copper foil of the outer layer CCL 10 " The outer circuit 10b " results in a multilayer rambus substrate 1 'being manufactured.

As a result, other Rambus laminated substrates 1 'laminated only by the inner and outer layers CCL 10' and 10 " have a uniform insulating distance and thickness without significant variation compared to the conventional lamination method by a fixing pin or rivet. The impedance characteristic of (1 ') is excellent.

At this time, the Rambus substrate (1 ') is usually laminated in six or more layers, the heater rod 70 due to the copper foil portion of the outer layer CCL (10 ") compared to the substrate 1 to which the separate copper foil 22 is attached ), There is a difference in the heating time, and the heating temperature of the heater rod 70 is shown in Table 2 below.

division Time (sec) Temperature (℃) Data on Rambus substrates with six or more layers, and Rambus substrates with four or fewer layers are 23-27 sec. 0.55t or less 28-32 200-400 0.56t-1.00t 33-37 " 1.01t-1.30t 38-42 " 1.31t-1.60t 43-47 " 1.61t-2.00t 50-60 " 2.01t-2.40 60-70 " 2.41t-3.20t 90-100 " 3.21t-4.00t 120-130 " 4.01t-5.00t 140-150 " 5.01t-6.00t 160-170 "

In this case, the time in Table 2 is delayed by about 5 seconds from the time of the multilayer board 1 in Table 1, but is delayed by the outer layer copper foil portion of the other Rambus substrate 1 ', which is often the copper foil portion. It is also removed and heated as a heating rod 70, the time is the same as the time in Table 1 also in the case of another Rambus substrate (1 ').

Next, FIG. 4 shows another lamination method of the multilayer board according to the present invention. An important feature is that the substrate (when heated by the heater rod 70 of the laminated substrate 1 preliminarily fixed as the fixing pin 30) It is performed in a state where the release sheet 40 is placed on the upper and lower sides of 1).

That is, as shown in Figure 5a, the pre-flags 20 are laminated on the outer layer of the above-mentioned laminated substrate 1, and if the heater rod 70 is brought into contact thereon to apply heat, after heating for a predetermined time , The laminated substrate 1 is preliminarily fixed, but the preflag 20 of the outer layer is fused to the heater rod 70, which makes the copper foil 22 laminated state of the substrate 1 poor, and the copper foil Insulation distance deviation between 22 and CCL 10 is severely generated, and at the same time, substrate thickness deviation is generated, resulting in poor substrate impedance as described above. In the case of the substrate 1, reliability is inferior due to poor impedance.

Therefore, after the above-described release sheet 40 is placed on the outer layer of the laminated substrate 1, even if heat is applied, the release sheet 40 has not yet been fused between the preflag 20 and the heater rod 70. To prevent the above-described impedance failure of the substrate 1, and after the heater rod 70 is heated, the release sheet 40 is removed at the same time as the fixing pin 30, and then the pressing operation of the laminated substrate 1 is performed. In this case, the release sheet 40 has a heat resistance temperature of about 400 ° C. or less, and uses a Teflon film coated with Teflon on the surface of the glass fiber material at a ratio of 30 and 70.

On the other hand, even when the release sheet 40 is used, the heating temperature of the heater rod 70 is 200-400 ℃, the heating time according to the thickness of the laminated substrate 1 is shown in Table 1.

Next, the measured values of the eight-layer Rambus substrate 1 by the conventional rivet fixing method and the bonding fixing method by the heater rod 70 of the present invention are shown in Table 3 below.

division Board thickness (mm) Cp (scatter diagram) Rivet Method 1.297t 0.918 Bonding Method (Invention) 1.281t 1.244

As can be seen from Table 3 and Figure 4, when comparing the distribution (Cp), that is, the distribution of the reference thickness of the rambus laminated substrate (1) of the present invention and the conventional Ribeck-type laminated substrate 200, in the case of the present invention It can be seen that the scattering degree is close to 1.3, which is an outlier value, which indicates that the thickness variation of the laminated substrate 1 is small when the bonding method by the heater rod 70 of the present invention, in particular, when the release sheet 40 is used. have.

On the other hand, the present invention is shortened by about 40 minutes of work time compared to the preliminary fixing of the laminated substrate by a fixed pin or riveting method, the productivity of the overall 33 or more improved, the need for tools such as rivets cost more than hundreds of millions of years There is a reduction effect, the thickness variation of about 30μm by the fixing pin or rivets is reduced, and the product yield is improved by about 10.

As described above, according to the method of laminating the multilayered printed circuit board of the present invention, by pre-fixing and preliminarily fixing the laminated preflags during the laminating operation of the multilayered printed circuit board, the entire crimping operation is performed, and thus the work by the fixing pin or the rivet is performed. By preventing time delay or insulation distance deviation, thickness deviation and cost increase, the overall productivity is further improved.

In addition, when pre-fixing of the multilayer board, the pre-flag is fused to the heater rod simply as a release sheet, it is effective to facilitate the multilayer printed circuit board stacking operation.

Lastly, it is possible to laminate the insulation distance and thickness uniformly during the lamination work of the rambus substrate used in the rambus system, thereby improving the impedance characteristics.

While the invention has been shown and described with respect to specific embodiments thereof, it will be appreciated that various changes and modifications can be made in the art without departing from the spirit or scope of the invention as set forth in the following claims. Those of ordinary skill will want to know easily.

Claims (19)

In the method of laminating a multilayer printed circuit board, Pre-lamination steps of sequentially stacking one or more pre-flags 20 and multi-layer CCLs 10, and then temporarily fixing them with fixing pins 30 to prepare a laminated substrate 1; Preliminary fixing the laminated substrate (1) by applying heat for a predetermined time as a heating means (70) for moving up and down the upper and lower sides of the laminated substrate (1); And, A substrate stacking step of removing the fixing pins 30 of the preliminarily fixed laminated substrate 1 and pressing them by pressing by heating and pressing; Laminating method of a multilayer printed circuit board, characterized in that configured as The method of claim 1, wherein the preliminary laminated substrate (1) is laminated with a preflag (20) on its outer layer. The method of claim 1, wherein the laminated substrate 1 comprises a rambus substrate. 2. The method of claim 1, wherein the laminated board is composed of another Rambus board (1 '). 5. The RAMB substrate 1 'according to claim 4, wherein the RAMB substrate 1' includes a multilayer inner layer CCL 10 'having an inner layer circuit 10a', one or more preflags 20, and an inner layer circuit of one side as an outer layer. 10a ") outer layer CCL (10") laminating method characterized in that the laminated According to claim 1, wherein the heating means 70 is composed of a heater rod 70 that moves up and down as a cylinder, the heating temperature by the heater rod 70 is characterized in that consisting of 200-400 ℃ Of multilayer printed circuit boards The method of claim 1, wherein the preliminary fixed laminated substrate (1) is formed of six or more layers, the thickness of which is heated at multiple points as the heating means (70) for 0.5-6t-6.00t for 23-165 sec. Lamination method of multilayer printed circuit board 5. The method according to claim 1 or 4, wherein the other Rambus laminated substrate 1 'is formed of six or more layers and has a plurality of points as the heating means 70 for a thickness of 0.56t-6.00t at 28-170 sec. Lamination method of multilayer printed circuit board, characterized in that heated in The method of claim 1, wherein the preliminary fixed multilayer board 1 is formed in four layers or less so that the heating means 70 is heated at multiple points for 18-22 sec. 5. The method according to claim 1 or 4, characterized in that the preliminarily fixed Rambus laminated substrate (1 ') is formed in four layers or less so that the heating means (70) is heated at multiple points for 23-27 sec. Stacking method of multilayer printed circuit board In the method of laminating a multilayer printed circuit board, Preliminarily stacking one or more insulating layers 20 and CCL 10 sequentially and then temporarily fixing them with fixing pins 30 to prepare a laminated substrate 1; After releasing the release sheet 40 on the upper and lower sides of the laminated substrate 1, the heating rod 70 moves upwards and downwards as a cylinder 60 at a plurality of points on the surface thereof, and is laminated by applying heat for a predetermined time. Pre-fixing the substrate 1; And, A substrate lamination step of removing the release sheet 40 and the fixing pin 30 of the preliminarily fixed laminated substrate 1 and pressing the sheet by pressing by heat and pressing; Stacking method of a multilayer printed circuit board, characterized in that comprising a 12. The method of claim 11, wherein the preliminary laminated substrate 1 is laminated with a preflag 20 on its outer layer. 12. The method of claim 11, wherein the laminated substrate 1 comprises a rambus substrate. 12. The method of claim 11, wherein the heating temperature by the heater rod 70 is 200-400 ° C. 12. The multi-layer printing according to claim 11, wherein the preliminarily fixed laminated substrate 1 is formed of six or more layers, and the heater rod 70 is heated for 23 to 165 sec at a thickness of 0.56t-6.00t. Stacking method of circuit board 12. The method of claim 11, wherein the preliminarily fixed laminated substrate 1 is formed in four layers or less, and the heater rod 70 is heated for 18 to 22 sec. 12. The method of claim 11, wherein the release sheet 40 to block the fusion of the heater rod 70 and the upper, lower pre-flags 20, characterized in that consisting of a Teflon-coated Teflon film on the surface of the glass fiber material Lamination method of multilayer printed circuit board 18. The method of claim 17, wherein the release sheet 40 is coated with Teflon on a glass fiber material at a ratio of 30 and 70. The method of claim 11, wherein the heat resistant temperature of the release sheet 40 is 400 ° C. or less.