KR20000019002A - Semiconductor package dedicated printed circuit board for electrostatic prevention - Google Patents

Abstract

PURPOSE: A semiconductor package dedicated printed circuit board is provided to make an electrostatic of a semiconductor chip become an outflow into a metal mold by contacting a ground dedicated protrusion to the metal mold at molding. CONSTITUTION: The semiconductor package dedicated printed circuit board comprises: a chip loading portion formed to load a semiconductor chip on an upper part of a resin substrate; circuit patterns (12) formed at all directions of the chip loading portion; a solder mask (15) coated on the upper part of the resin substrate so as to protect the circuit patterns; a via hole for connecting the circuit patterns to an upper part and a lower part of the resin substrate; a solder ball land connected to the lower part of the resin substrate, for forming an area where the solder ball is melt and attached; a solder mask coated at an area except the solder ball land; a gold gate formed at the resin substrate toward the chip loading portion to protect the semiconductor chip, wherein two lead lines are extracted from bus lines (50) to be removed after this and are merged by one lead line; wherein by coating the merged part opening the solder mask, a ground dedicated protrusion part (22) is formed by an excessive current issued at coating and has a thickness larger than that of the solder mask.

Description

Printed circuit board for semiconductor package to prevent static

The present invention relates to a printed circuit board for a semiconductor package for preventing static electricity, and more particularly to a printed circuit board that can easily discharge static electricity from a printed circuit board or a semiconductor chip generated during molding to the mold. .

Recently developed semiconductor chips have a low driving voltage, a small allowable error of the voltage, and a fine circuit pattern. Thus, in a packaging process of assembling a semiconductor chip, the semiconductor chip is temporarily stored after static electricity is accumulated. The problem of frequently discharging the chip to damage the semiconductor chip occurs. Such a problem is that the semiconductor chip is easily damaged by sudden discharge of static electricity, especially when the printed circuit board is removed from the mold or the printed circuit board is in contact with other materials after the molding process of the printed circuit board.

Conventionally, in order to prevent this, a predetermined ground plate 22 'is formed on the bottom surface of the printed circuit board, which will be described below with reference to FIGS. 1A to 2.

First, the overall structure of the printed circuit board 10 will be described. A resin substrate (not shown), a chip mounting portion 16 formed so that a semiconductor chip can be mounted on an upper surface of the resin substrate, and the chip mounting portion are described above. The circuit pattern 12 formed radially around the periphery 16, the solder mask 15 coated on the upper surface of the resin substrate so as to protect the circuit pattern 12, and the circuit pattern 12 are formed on the resin substrate. Conductive via holes 13 connected to the upper and lower portions, solder bores 14 connected to the lower part of the resin substrate by the via holes 13 so that the solder balls are fused, and solder ball lands below the resin substrate. A solder mask 15 coated in a region excluding 14, a ground signal of the semiconductor chip is connected, a gold gate 17 formed on an upper surface of the resin substrate so that an encapsulant is introduced, and the printed circuit board 10 The solder mask 15 coated on the upper and lower parts of the It is limitedly open and is formed slightly higher than the height of the solder mask 15 through this open area, and is composed of a substantially rectangular ground flat plate 22 'connected to the ground signal of the semiconductor chip.

Reference numeral 25 in the figure is a ground ring formed on the outer periphery of the chip mounting portion 16, which is connected to all the ground wires of the semiconductor chip is transferred to the gold gate 17 through the ground circuit pattern 21. The reason for transmitting the ground signal of the semiconductor chip to the gold gate 17 is to determine whether the wire pattern of the circuit pattern 12 and the semiconductor chip is poor in the future or to form the common ground area to secure the necessary circuit pattern as much as possible. For sake.

The printed circuit board 10 having such a structure is simply grounded by placing the printed circuit board 10 on the mold molds 30a and 30b in the molding step of the semiconductor package manufacturing process as shown in FIG. do. That is, the ground plate 22 'is formed slightly higher than the height of the solder mask 15 on the bottom of the printed circuit board 10, so that the ground plate 22' is grounded to the mold mold.

In the figure, reference numeral 40 is a semiconductor chip, and 42 is a conductive wire.

Therefore, the charge generated by the encapsulant rubbing with the semiconductor chip 40, the wire 42 and the printed circuit board 10 during the injection of the encapsulant in the molding step is not accumulated in the semiconductor chip, 22 ') flows into the mold 30b to prevent damage to the semiconductor chip due to sudden electrostatic discharge.

However, such a conventional printed circuit board has a problem in that it takes a long manufacturing time and a high manufacturing cost by additionally performing two additional plating processes during the manufacturing process of the printed circuit board, in order to form the ground flat plate. .

In addition, it is very difficult to constantly control the thickness by forming the ground flat plate, and at the same time there is a problem that it is impossible to apply directly to the semiconductor package manufacturing process based on mass production because the yield is low.

The present invention has been made to solve the above-mentioned conventional problems, by forming a ground projection on one side of the printed circuit board without adding a separate process, the ground projection during molding the mold The present invention provides a printed circuit board for a semiconductor package for preventing static electricity, which is in contact with and can easily discharge static electricity from a semiconductor chip to a mold.

1A is a plan view showing a conventional printed circuit board, FIG. 1B is a bottom view thereof, and FIG. 1C is an enlarged view of portion A of FIG. 1B.

2 is a state diagram illustrating a state in which a conventional printed circuit board is in contact with a mold.

FIG. 3A is a bottom view of the printed circuit board according to the present invention, FIG. 3B is an enlarged view of a portion B of FIG. 3A, and FIG. 3C is a sectional view taken along the line CC 'of FIG. 3B.

-Description of the main symbols in the drawings-

10; Printed circuit board 11; Resin board

12; Circuit pattern 13; Conductive via hole

14; Solder borland 15; Solder mask

16; Chip mounting part 17; Gold gate

18; Tooling holes 19; Singulation Hall

20; Via hole for ground 21,24; Ground Circuit Pattern

22; Ground projection 25; Ground ring

30a; Prize mold 30b; Lower mold

40; Semiconductor chip 42; Conductive Wire

50; Bus lines 51,52,53; Lead wire

In order to achieve the above object, a printed circuit board for a semiconductor package for preventing static electricity according to the present invention includes a resin substrate; A chip mounting part formed on the upper surface of the resin substrate so that a semiconductor chip can be mounted; A circuit pattern formed radially on all sides of the chip mounting part; A solder mask coated on the resin substrate to protect the circuit pattern; A via hole connecting the circuit pattern to the upper and lower parts of the resin substrate; A solder ball land connected to the lower portion of the resin substrate by the via hole to form an area in which solder balls may be fused; A solder mask coated on a region of the resin substrate except for solder ball lands; In the printed circuit board consisting of a gold gate formed on the resin substrate toward the chip mounting portion to protect the semiconductor chip, which is connected to the circuit pattern of the printed circuit board, two bus lines that are removed later on the resin substrate A branched lead wire is formed, and the two lead wires are connected to a ground circuit pattern to which a ground signal is output while being matched with one lead wire, and a solder mask is opened at a portion where the two lead wires coincide. The ground projection is formed thicker than the thickness of the solder mask, so that the plating area is in contact with the mold during molding, so that static electricity formed on the semiconductor chip and the printed circuit board is discharged to the mold.

In this way, the current flowing through the bus lines during the plating operation to the two lead wires flows into the lead wires matched with one. Then, an overcurrent flows through the lead wire matched with the one, and the solder mask is opened to form a ground protrusion in the matched lead wire, whereby a ground protrusion having a relatively large thickness is formed by the overcurrent.

On the other hand, after bonding a semiconductor chip to the chip mounting portion of the printed circuit board, connecting the semiconductor chip and the circuit pattern with a conductive wire, and mounting the printed circuit board to a mold to be molded, the printed circuit board in the mold The ground projection of the contact comes in contact. Then, during the molding process, static electricity that is induced from the semiconductor chip due to friction between the encapsulant, the semiconductor chip, the conductive wire, and the printed circuit board flows out into the mold through the ground protrusion, and thus the semiconductor chip is suddenly discharged. This damage can be prevented beforehand.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings such that those skilled in the art can easily implement the present invention. The description is omitted and the same reference numerals are used.

FIG. 3A is a bottom view of the printed circuit board 10 according to the present invention, FIG. 3B is an enlarged view of a portion B of FIG. 3A, and FIG. 3C is a cross-sectional view taken along the line CC 'of FIG. 3B.

First, as shown in FIGS. 3A and 3B, a plurality of solder bores 14 are formed on the bottom surface of the printed circuit board 10 so that a plurality of solder balls may be fused later, and the outer peripheral edges of the solder bores 14 are formed. A plurality of circuit patterns 12 (shown schematically) are formed in the solder ball lands 14. The circuit patterns 12 are all connected to the bus lines 50 on the resin substrate 11, and the bus lines 50 are removed during the manufacturing process of the printed circuit board 10. Shown.

In the bus line 50, two branched lead wires 51 and 52 are formed in an inverted triangle shape on one side of the circuit pattern 12, and the two lead wires 51 and 52 are one lead wire again. The ground signal is connected to the ground via hole 20 to which the ground signal is output. The via hole 20 is also connected to the gold gate 17, which is connected to the ground ring 25 as in the prior art.

The lead wires 51, 52, and 53 are all coated with a solder mask 15 like the circuit pattern 12, but the lead wires 51, 52, and 53 are joined to each other, that is, one lead wire 53. With the solder mask 15 open, the ground protrusions 22 are formed thicker than the thickness of the solder mask 15.

In addition, since the ground circuit pattern 25 is formed to the ground via hole 20 connected to the gold gate 17 when the ground protrusion 22 extends, the ground signal of the semiconductor chip 40 is generated. The gold gate 17, the ground via hole 20, the circuit pattern 25, and the protrusion 22 flow out into the mold.

Here, the two lead wires 51 and 52 are smaller in thickness and width than the bus line 50, and one lead wire 53 in which the two lead wires 51 and 52 coincide is the two lead wires 51, Since the thickness and width are smaller than those of 52, overcurrent flows through the lead wires 53 in which the two lead wires 51 and 52 coincide during the plating operation, and the thickness of the solder mask when the ground protrusion 22 is plated is formed. It is formed thicker than (15).

The ground protrusion 22 may simultaneously perform a bonding process (not shown) of the circuit pattern, the gold gate 17 and the ground ring 25 at the same time as plating, thereby eliminating the need for a separate additional process as in the prior art.

In addition, the ground protrusion 22 is formed of gold (Au), but not limited thereto, and various conductive metals may be used.

In this way, the above-described ground protrusion 22 protrudes to the bottom surface of the printed circuit board 10, thereby contacting the surface of the mold during the molding operation, and thus the semiconductor chip 40 or the printed circuit board 10. All of the static electricity induced in the circuit pattern 12, etc. of the outflow to the metallic mold. That is, since the circuit patterns 12 of the semiconductor chip 40 or the printed circuit board 10 are all connected to the gold gate 17, the static electricity induced from the semiconductor chip or the like is used for the gold gate 17 and the ground. By leaking to the outside through the via hole 20, the circuit pattern 25, the protrusion 22, and the metallic mold, it is possible to prevent the semiconductor chip 40 from being destroyed by the sudden discharge of static electricity.

Here, the ground protrusion 22 is formed on the bottom surface of the printed circuit board 10, but may also be formed on the upper surface, the position is preferably the outer periphery of the region in which the encapsulant is molded.

As described above, although the present invention has been described with reference to the above embodiments, the present invention is not limited thereto, and various modifications may be made by those skilled in the art without departing from the scope and spirit of the present invention.

According to the printed circuit board for the semiconductor package for preventing static electricity according to the present invention, by drawing the two lead wires from the bus line to be removed later, combine them into a single lead wire, the soldered part is opened by plating the combined parts, The overcurrent generated during plating causes the ground protrusion to be formed thicker than the thickness of the solder mask.

Therefore, it is possible to easily form the ground protrusions having a predetermined thickness or more by one plating operation, and also to easily control the thickness of the ground protrusions, and to greatly improve the yield, and also to prevent static electricity from the semiconductor chip. By easily flowing out, the damage of the semiconductor chip can be prevented in advance.

Claims (3)

A resin substrate; A chip mounting part formed on the upper surface of the resin substrate so that a semiconductor chip can be mounted; Circuit patterns formed on all sides of the chip mounting portion; A solder mask coated on the resin substrate to protect the circuit pattern; A via hole connecting the circuit pattern to the upper and lower parts of the resin substrate; A solder ball land connected to a lower portion of the resin substrate by the via hole to form an area in which solder balls may be fused; A solder mask coated on a region of the resin substrate except for solder ball lands; In the printed circuit board made of a gold gate formed on the resin substrate toward the chip mounting portion to protect the semiconductor chip, The bus line, which is connected to the circuit pattern of the printed circuit board, is subsequently removed, and two branched lead lines are formed on the resin substrate, and the two lead wires are matched with one lead line again to output a ground signal. A ground protrusion is formed at a portion where the two lead wires coincide with the solder mask and is thicker than the thickness of the solder mask so that the plating region contacts the mold during molding. Printed circuit board for a semiconductor package for preventing static electricity, characterized in that the static electricity formed in the chip and the printed circuit board to be discharged to the mold. 2. The method of claim 1, wherein the two leads are smaller in thickness and width than the bus lines, and the one matched lead is smaller in thickness and width than the two leads, so that an overcurrent flows in the matched leads during plating. Printed circuit board for a semiconductor package for preventing static electricity, characterized in that the thickened. The printed circuit board of claim 1, wherein the ground protrusion is formed of gold.