KR950001269B1 - Method of transcribing a cream solider on a printed circuit board - Google Patents

Abstract

A cream solder is printed on the bonding position of a hole and a parts of chip on the printed circuit board. The chip parts and lead parts are arranged at the fixed position, and soldered in the gross. A stencil having several transcribing holes is installed on the same position of lead frame holes and chip parts. A fixed quantity of the cream solder is squeezed in the transcribing hole of the stencil.

Description

How to transfer the cream solder onto the printed circuit board

1 is a schematic process diagram of a conventional electronic component mounting method.

2 is a schematic process diagram of yet another conventional electronic component mounting method.

FIG. 3 is a schematic process diagram further showing that the cream solder transfer method onto the printed circuit board of the present invention is further configured in the process of FIG.

* Explanation of symbols for main parts of the drawings

10: stencil 11: transfer ball

15: roller 20: circuit board

21: circuit board hole 30: transfer plate

31: transfer pin 40: chip component

41: lead part 42: cream solder at chip part mounting position

43: cream solder

The present invention relates to a method for mounting an electronic component such as a chip, a lead, etc. on a substrate, and more particularly, transfer a certain amount of cream solder to a hole and a chip component mounting position on the substrate prior to mounting the electronic component on the substrate. The present invention relates to a method of transferring a solder solder to a printed circuit board, which prevents the chip-like component from being deformed, poorly soldered, and unnecessary lead bridges, reduces product defects, and improves productivity.

Recently, the trend of miniaturization, simplification, and high performance of various products and components in the electric and electronic industries has been remarkable. To satisfy these demands, they are precisely mounted on a circuit board without changing the physical properties of various electrical and electronic components. How to make it absolutely necessary.

In general, polyimide, polyester, polyetherimide film and the like are mainly used as substrate materials of printed circuit boards because of their excellent thermal, electrical, and mechanical properties. The substrate is coated with an adhesive material and a metal foil such as copper or aluminum is adhered to the substrate, and the screen and the dry film photoresister are used to etch the circuit and the conductive metal foil to be etched, followed by insulation and circuit protection. By applying a coverlay film for manufacturing a printed circuit board.

In order to mount an electronic component on a circuit board manufactured by the above-described method, as shown in FIG. 1, a preliminary solder is placed at a position where the chip-shaped component 40 is to be mounted by a screen printing method or the like. The chip-shaped component 40 is placed in the pre-soldering position and then fixed by reflow. Then, the lead-type component 41 is inserted into the hole 21 on the printed circuit board 20 and waved again. Although the finished product was manufactured by bonding by the method of soldering (wave soldering), in the above method, the pre-mounted chip-type component 40 is deformed by heat or is poorly soldered when lead soldering the lead-type component 41. There was a problem that occurred a lot. In other words, wave soldering is performed in a molten lead bath. Since the melting point of lead is 327.4 ℃, the ambient temperature is considerably high, so that not only the appearance of the pre-mounted chip-shaped parts but also the physical properties are changed, so that a product having a desired characteristic value is often obtained. It is an inhibitor.

2 is a schematic process diagram showing another conventional electronic component mounting method, in which preliminary solder is placed at a position where the substrate hole 21 and the chip-shaped component 40 are to be mounted by screen printing or the like. The chip-type component 40 is placed on the preliminary soldering position with a chip mounter, the lead-type component 41 is inserted into the holder 21 on the printed circuit board 20, and then reflow soldering is performed in a batch. As a result of the adhesion of the method, many problems as described in FIG. 1 have been generated, which is a detrimental factor in the high performance of the product.

Accordingly, the present invention has been made to solve the above-mentioned problems, the object of which is to transfer a certain amount of the cream solder to the hole and the chip component mounting position on the substrate so that the denaturation of the chip-shaped components, solder failure and unnecessary lead bridge The present invention provides a method for transferring a cream solder to a printed circuit board which can prevent the production, reduce the defect rate of the product, and improve productivity.

In order to achieve the above object, the present invention includes a stencil in which a plurality of transfer holes are provided at the same position as a hole in which a lead part on the printed circuit board is inserted and a chip part mounting position, and a transfer hole of the stencil. A certain amount of cream solder is squeeged in the squeegee, and the transfer pin of the cream solder electronic printer is joined to the protruded electronic board, so that the hole on the printed circuit board and the chip part are transferred to a position to be bonded.

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

FIG. 3 is a schematic process diagram showing further configuration of the present invention in a conventional process, wherein the cream solder 42 is printed at the attachment position of the hole 21 and the chip component 40 on the printed circuit board 20, In the electronic component mounting method in which the chip parts 40, the lead parts 41, and the like are arranged on the cream solder 42 and soldered in a batch, the lead parts on the printed circuit board 20 And a stencil 10 in which a plurality of transfer holes 11 are majored at the same position where the hole 21 and the chip component 40 to which the 41 is inserted are mounted, and the stencil 10 Inject a predetermined amount of the cream solder (42, 43) into the transfer hole (11) of the squeegee (squeeging) in close contact with the upper and lower surfaces of the stencil 10 with a roller (15) to make the amount constant Stencil the transfer plate 30, the transfer pin 31 of the cream solder electronic printing machine facing the transfer hole 11 of the stencil 10 protruding It presses by the transfer hole 11 of the slab 10, and transfers it to the position where the hole 21 and the chip component 40 on the printed circuit board 20 will adhere | attach.

The operation and effects of the present invention further configured as described above will be described.

The printed circuit board 20 is formed by applying an adhesive to a substrate such as polyimide, polyester, polyester imide, and bonding a metal foil such as copper or aluminum, and then drawing a circuit using a screen printing or dry film photoresist and conducting metal foil. After etching, the coverlay film is coated for insulation and circuit protection, and the circuit board hole 21 is formed at the position where the lead part 41 is inserted. In addition, a stainless steel plate is used as the material of the stencil 10 and the same position as that of the printed circuit board hole 21 formed at the position where the lead part 41 on the printed circuit board 20 is inserted. And by forming and using the stencil hole 11 on the mounting position of the chip component 40 it was possible to excellent precision.

Meanwhile, the rollers are rolled on both sides of the stencil 10 and the cream solder 43 is applied at the same time to uniformly fill the stencil hole 11 with a certain amount of the cream solder 43, and then print. The transfer plate 30 formed at the same position as the hole 21 on the circuit board 20 and having the transfer pin 31 having the same thickness of the stencil 10 is pressed with the stencil 10 while pressing the substrate. The cream solder 43 filled in the stencil hole 11 at the same position as the insertion part 21 of the lead part 41 of the lead part 41 is injected into the hole 21 on the printed circuit board 20, and the chip of the substrate 21 is inserted. The cream solder of the stencil hole 11 formed at the same position as the mounting position of the component 40 is transferred to the mounting position of the chip component 40 of the substrate 21.

By applying the cream solder 43 on both sides of the stencil 10 and removing the cream solder 43 attached to the stencil hole 11, a certain amount of the cream solder 43 is formed on the hole 21 on the printed circuit board 20. And the chip component 40 to be transferred to the mounting position.

Meanwhile, the process of arranging the chip component 40 on the transferred cream solder 43 and inserting the lead component 41 into the hole 21 of the printed circuit board 20 is generally performed in the art. All methods can be used, but it is particularly effective to use industrial Robert. In addition, it may be arranged or inserted using a chip mounter (lead mounter) or a lead mounter commonly used in the art.

When the chip component 40 and the lead component 41 are arranged on the printed circuit board 20 by the above-described method, the finished product is manufactured by soldering by the reflow soldering method.

As described above, the soldering defect generated in the conventional method of inserting and wave soldering the lead component of the present invention, which transfers a predetermined amount of the cream solder, inserts the lead component, and then reflows soldering, generates a large amount of lead bridges, and chip shapes. It fundamentally solved the cause of defects caused by the deformation of parts, and it is possible to supply a certain amount of cream solder by squeezing both sides of the stencil by using stainless stencil hole as a stencil.

Claims (1)

The cream solder 42 is printed in the hole 21 and the chip component 40 attachment position on the printed circuit board 20, and the chip component 40, the lead component 41, and the like are placed on the cream solder 42. In the electronic component mounting method in which the solder parts are arranged in a predetermined position and soldered in a batch, at the same position as the mounting position of the hole 21 and the chip component 40 in which the lead component 41 on the printed circuit board 20 is inserted. A plurality of transfer holes 11 is provided with a stencil (tencil) (10), and squeeged a certain amount of cream solder (42, 43) in the transfer hole 11 of the stencil (10) And pressing the transfer plate 30 on which the electronic pin 31 of the cream solder electronic printer protrudes, thereby transferring the hole 21 on the printed circuit board 20 to the position where the chip component 40 is to be bonded. Cream solder transfer method to a circuit board.