KR100610053B1 - Moulding stripper for slot processing in pcb fabrication - Google Patents

Abstract

The present invention relates to a slot processing technology of a printed circuit board, and more particularly, to a technique for preventing cracks in a printed circuit board during processing of a slot by using a die manufactured punch.

According to the present invention, a stripper structure for fixing a printed circuit board in a process of manufacturing a slot using a die punch is made to have a concave-convex pattern so that the epoxy portion of the printed circuit board is not pressed down. It is effective to fix it firmly. As a result, cracks are prevented from occurring on the printed circuit board during the punching process.

Printed circuit board, stripper, gold plating.

Description

Mold stripper for slotting a printed circuit board {MOULDING STRIPPER FOR SLOT PROCESSING IN PCB FABRICATION}

1A-1C show an example of a printed circuit board with a slot.

2A and 2B schematically show a method of manufacturing a slot in a printed circuit board using a punch made of a mold according to the prior art;

3 is a view showing a process of manufacturing a slot in a printed circuit board using a mold punch according to the present invention.

Figure 4 is a view showing the structure of the stripper of the concave-convex shape used in the mold punching operation according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: slot

20: Au plating bus line

100: package substrate

200: punch made of a mold

410 stripper

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to slot processing technology of a printed circuit board (PCB), and in particular, a technique for preventing cracks in a printed circuit board during processing a slot by using a punch made of a mold. It is about.

In recent years, as the number of semiconductor pins increases and the package shape becomes complicated, a technique of directly placing a semiconductor chip on a package substrate and wire bonding between the semiconductor plate and the gold plate bonding pad of the package substrate is adopted. It is becoming.

However, when the length of the bonding wire between the chip and the package substrate is increased, the parasitic resistance component or capacitance component is increased and the electrical properties are deteriorated. Therefore, efforts have been made to make the bonding wire as short as possible. In this regard, a board on chip (BOC) method is used in which a semiconductor chip is mounted on a rear surface of a package substrate and a wire bonding gold plating bonding pad on the front surface of the package substrate is bonded through a slot from a bonding pad of the semiconductor chip. Figure 1a schematically shows a package substrate to which the BOC method commonly used in accordance with the prior art is applied.

That is, the above-described method is called a board on chip (BOC) in the sense that the package substrate on which the semiconductor chip is mounted is reversed and mounted on the rear surface unlike the conventional method. In order to apply the BOC method, a slot must be processed on a package substrate, and a router is used to process the slot. Here, the router method may be referred to as an NC cutting method, which is a method of cutting a portion to be slotted by using a type of saw drill.

Referring again to FIG. 1A, a slot 10 of a package substrate 100 is illustrated, and a gold plating bonding pad and a bus line (which may be wire bonded connections around a slot 10 processed on the package substrate 100) are illustrated. 20 is shown. Here, to make a slot, a hole is drilled through a router using a bit, that is, a saw blade.

By the way, when the slot is formed by the above-described router processing method, the copper foil residue (called 'burr') and the like generated while cutting the copper foil formed on the multilayer printed circuit board in the cutting process remains near the cut gold plating. It can cause electrical defects. In addition, the method of forming slots using a router has a disadvantage in that processing time is considerably taken because each slot to be formed in the package substrate must be cut one by one. 1B and 1C show front and rear sides of a printed circuit board to be slotted.

As described above, in order to shorten the time taken in the slot manufacturing process, there is a method in which a punch is made of a mold and press-punched on a printed circuit board to drill a slot. As such, when the slot is formed by using the mold punch, the punch is pushed down as it is while moving the punch to a desired position, thereby reducing the slot processing time.

2 is a view schematically showing a method of manufacturing a slot on a printed circuit board using a punch made of a mold according to the prior art. Referring to FIG. 2, in the prior art, a slot 10 is formed by placing a printed circuit board 100 to be subjected to slot processing on a die 400 and lowering the punch 200 manufactured by a mold for a moment.

By the way, the printed circuit board made of a multi-layer structure of the plating line and the epoxy resin is different in hardness of each layer (particularly, the hardness between the copper foil layer and the resin layer), so that cracks in the epoxy resin layer during the punching process (crack; 88) occurs. That is, cracks generated in the epoxy layer may lead to cracks, and when the molding is performed after wire bonding in a subsequent process, defects due to migration may occur. That is, once cracks are generated in this way, the resin layer in which the cracks are generated during the subsequent molding process becomes white as if bruised, which is referred to in the art as whitening phenomenon (White-C).

Accordingly, an object of the present invention is to use a punch made of a mold for forming a slot of a printed circuit board, but to provide a technique for preventing cracks in the printed circuit board during the press punching process, resulting in migration or whitening. It is.

In order to achieve the above object, the present invention is a predetermined position of the printed circuit board for mounting the semiconductor chip to connect the bonding pad of the semiconductor chip and the gold plating bus line of the concave-convex shape of the printed circuit board with a bonding wire to each other. A method of forming a slot by instantaneously lowering and punching a punch made in a mold, the method comprising: a stripper contacting an upper surface of the printed circuit board and applying a force downward to fix the printed circuit board, wherein the stripper Slots of a printed circuit board for punching a stripper placed on the printed circuit board having a concave-convex shape designed to contact only an epoxy portion between the gold plating bus lines so as not to directly contact the gold plating bus lines of the printed circuit board. It provides a formation method.

The present invention allows the stripper to press on the printed circuit board to fix the printed circuit board by forming a slot in the printed circuit board using a die punched punch, while the stripper does not press the gold plating bus line, By contacting only the epoxy sites, the PCB board is prevented from cracking.

Hereinafter, the slotting technique according to the present invention will be described in detail with reference to FIGS. 3 and 4.

Figure 3a is a view showing a process for manufacturing a slot on a printed circuit board using a mold punch in accordance with the present invention. Referring to Figure 3a, unlike the prior art jig 410 is prepared on the printed circuit board. This is called a stripper 410, and the present invention prevents cracking of a printed circuit board by characteristically designing the structure of the stripper 410.

In the case of the present invention, the stripper 410 only between the epoxy portions between the gold plating bus lines 105 of the printed circuit board 100 placed on the die 400 when the punch 200 is lowered and pushed down for slot drilling. Press to make punching easier. Moreover, as a preferred embodiment of the present invention, the stripper 410 according to the present invention has a stripper (shape) or a jag type as shown in FIG. 410 can be prevented from damaging the gold plating bus line.

4 is a plan view showing the structure of a stripper according to the present invention. Referring to Figure 4, the stripper 410 according to the present invention does not cover the gold plating bus line 105, unlike the prior art, and only contacts the epoxy portion 106.

The structure of the stripper 410 according to the present invention has the advantage that the stripper can fix the space portion of the resin material without pressing the gold plating bus line 105 by evenly spreading the impact applied to the fracture surface on the epoxy surface. have.

As a preferred embodiment of the present invention, the stripper 410 is preferably to have a concave-convex shape, and the corner portion of the concave-convex may be rounded to have a curvature in order to secure a manufacturing tolerance.

Referring again to Figure 3b, when punching using a stripper according to the present invention, it can be seen that no crack occurs unlike the prior art. 3C illustrates an embodiment in which the stripper 410 presses not only the gold plating bus line 105 but also the resin portion 105 therebetween, but rather than the embodiment disclosed in FIG. 3C. More preferred is the embodiment shown in FIG.

That is, the stripper according to the preferred embodiment of the present invention has a concave portion having a width larger than the width of the bus line 105 and the protrusion 411 having a width smaller than the gap between the gold plating bus lines 105 of the printed circuit board. The irregularities 411 and 412 having the portion 412 are repeated so that the stripper 410 is gold when the stripper 410 is aligned with the gold plating bus line 105 to punch. It is characterized by pressing only the portion 106, ie the epoxy portion 106, between the bus lines 105 without being in contact with the plating bus line 105.

The foregoing has outlined rather broadly the features and technical advantages of the present invention to better understand the claims of the invention which will be described later. Additional features and advantages that make up the claims of the present invention will be described below. It should be appreciated by those skilled in the art that the conception and specific embodiments of the invention disclosed can be readily used as a basis for designing or modifying other structures for carrying out similar purposes to the invention.

In addition, the inventive concepts and embodiments disclosed herein may be used by those skilled in the art as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. In addition, such modifications or altered equivalent structures by those skilled in the art may be variously changed, substituted, and changed without departing from the spirit or scope of the invention described in the claims.

As described above, the present invention has a gold play of the printed circuit board by having a concave-convex shape or a jag pattern in the structure of the stripper for fixing the printed circuit board in the process of manufacturing the slot by using a die punched punch There is an effect of fixing the epoxy portion firmly without pressing the casting electrode. As a result, cracks are prevented from occurring on the printed circuit board.

Claims (3)

In the method of mounting a semiconductor chip and punching a slot with a punch made in a mold at a predetermined position of the printed circuit board to connect the bonding pad of the semiconductor chip and the gold plating bonding pad of the printed circuit board with a bonding wire. And a stripper contacting the upper surface of the printed circuit board and applying a force downward to fix the printed circuit board by dispersing and acting a force on a die in a process of drilling by lowering and punching the punch. Wherein the stripper is placed and punched on the printed circuit board stripper designed to have a concave-convex shape to contact only the epoxy portion between the gold plating bus line so as not to directly contact the gold plating bus line of the printed circuit board Method of forming slots in a printed circuit board. The printing with a gold plating bus line for applying a uniform force to the printed circuit board and fixing the substrate on a die in fabricating a slot by instantaneously lowering and punching a punch formed in a printed circuit board. A stripper which is placed on a circuit board to disperse an impact applied to a fracture surface during a punching operation, wherein the stripper is larger than the width of the bus line and the protrusion having a width smaller than the distance between the gold plating bus lines of the printed circuit board. The irregularities with wide recesses are repeated so that when the stripper is aligned with the gold plating bus line and the punching operation is performed, the stripper is not in contact with the gold plating bus line, but between the bus lines. Characterized by pressing only parts, ie epoxy sites, The mold punch stripper for the printed circuit board. The stripper for punching the mold of the printed circuit board according to claim 2, wherein the corner portions of repeated irregularities of the stripper are curved to have a curvature.

Images