阅读说明：本技术 一种具有沟槽的深腔焊劈刀刀尖及其工作面的加工方法 (Machining method for tool point of deep cavity welding chopper with groove and working surface of tool point ) 是由 徐波 杨强 于 2020-04-30 设计创作，主要内容包括：本发明公开了一种具有沟槽的深腔焊劈刀刀尖,该劈刀刀尖的工作面上设有截面呈半圆形的沟槽,所述沟槽的长度等于劈刀刀尖的工作面的宽度,所述沟槽的半径为0.005mm～0.04mm,所述沟槽的内壁表面为粗糙面。本发明还提供了上述深腔焊劈刀刀尖工作面的加工方法,采用高精度电火花、皮秒激光或飞秒激光于劈刀刀尖的工作面上沿其宽度方向加工沟槽；采用微细电火花放电加工沟槽内壁表面的粗糙度。本发明具有利于劈刀的超声能量耦合,金丝焊点的形成及焊点形态良好,能够满足高精度的半导体封装要求的优点。(The invention discloses a deep cavity welding riving knife point with a groove, wherein the working surface of the riving knife point is provided with a groove with a semicircular section, the length of the groove is equal to the width of the working surface of the riving knife point, the radius of the groove is 0.005 mm-0.04 mm, and the inner wall surface of the groove is a rough surface. The invention also provides a processing method of the tool tip working surface of the deep cavity welding chopper, which is characterized in that high-precision electric sparks, picosecond lasers or femtosecond lasers are adopted to process grooves on the working surface of the tool tip of the chopper along the width direction of the working surface; and machining the roughness of the inner wall surface of the groove by adopting micro electric spark discharge. The invention has the advantages of being beneficial to the ultrasonic energy coupling of the riving knife, having good formation of gold wire welding spots and welding spot shapes and being capable of meeting the requirement of high-precision semiconductor packaging.)

1. The deep cavity welding riving knife point with the groove is characterized in that the groove with the semicircular section is arranged on the working surface of the riving knife point, the length of the groove is equal to the width of the working surface of the riving knife point, the radius of the groove is 0.005 mm-0.04 mm, and the inner wall surface of the groove is a rough surface.

2. The deep cavity welding riving knife point with the groove of claim 1, wherein the roughness of the inner wall surface of the groove is Ra0.1-Ra0.6.

3. A method for processing the working surface of the tool tip of the deep cavity welding and splitting tool with the groove according to claim 1 or 2, which is characterized by comprising the following steps:

s1, machining a groove on the working surface of the cutter point of the cleaver along the width direction of the working surface by adopting high-precision electric spark, picosecond laser or femtosecond laser;

and S2, machining the roughness of the inner wall surface of the groove by adopting micro electric spark discharge.

Technical Field

The invention relates to the field of microelectronics, in particular to a tool tip of a deep cavity welding and cleaving tool with a groove and a processing method of a working surface of the tool tip.

Background

The working surface of the cutter point of the traditional deep cavity welding chopper is not processed finely enough, and the roughness of the working surface of the cutter point of the chopper can not be adjusted, and the roughness of the working surface is a necessary condition for ultrasonic coupling of the chopper and a gold wire, an aluminum wire or a copper wire; different welding conditions need to correspond to different working faces and the roughness of the inner surface of the CG groove, the smoothness of the working face of the tool nose and the inner surface of the CG groove is better, the smoothness of the working face and the inner wall of the CG groove is not good, the ultrasonic energy of the riving tool is not favorably coupled to the gold wire, the aluminum wire or the copper wire, the formation of welding spots of the gold wire, the aluminum wire or the copper wire and the shape of the welding spots are damaged, and the high-precision semiconductor packaging requirement cannot be met.

Disclosure of Invention

Aiming at the problems, the invention provides a machining method for the tool tip and the working surface of a deep cavity welding chopper with grooves, which has the advantages of facilitating ultrasonic energy coupling of the chopper, forming a gold wire (or an aluminum wire or a copper wire) welding spot and having good welding spot shape and meeting the requirement of high-precision semiconductor packaging.

The technical scheme of the invention is as follows:

the utility model provides a deep cavity welds chopper knife tip with slot, this deep cavity welds the chopper and includes chopper handle of a knife and chopper knife tip, has straight through hole on the chopper handle of a knife, and the tail end in straight through hole is the loudspeaker form, and it is more convenient that the gold wire (or aluminium silk or copper wire) is sent into, has the wire feed hole on the chopper knife tip, is equipped with the cross-section on the working face of this chopper knife tip and is the semicircular slot, the length of slot equals the width of the working face of chopper knife tip, the radius of slot is 0.005mm ~ 0.04mm, the inner wall surface of slot is the rough surface.

The working principle of the technical scheme is as follows:

a semicircular groove is formed in the middle of the working surface of the tool tip of the riving tool, ultrasonic energy coupling of the riving tool is facilitated, meanwhile, space for stress release of welding spots on two sides of the groove is provided, and burrs are reduced in the welding process.

By adopting the technical scheme, the forming of the gold wire (or aluminum wire or copper wire) welding spot and the welding spot form are good, the high-precision semiconductor packaging requirement can be met, and the technical problem of low welding precision in high-precision semiconductor packaging is solved.

In a further technical scheme, the roughness of the inner wall surface of the groove is Ra0.1-Ra0.6, which is more beneficial to coupling ultrasonic energy to a gold wire, and solves the technical problems that the formation of a welding spot of the gold wire (or an aluminum wire or a copper wire) and the shape of the welding spot are damaged due to the fact that the inner surface of the groove is too smooth or too rough.

In a further technical scheme, the size of the semicircular groove depends on the length of the tool nose working surface, and the radius of the semicircular groove is small when the length of the working surface is small; the radius of the semicircular groove is large when the length of the working surface is large.

The invention also provides a method for processing the working surface of the tool nose of the deep cavity welding chopper with the groove, and the technical scheme is as follows:

a method for processing a tool tip working surface of a deep cavity welding and cleaving tool with grooves comprises the following steps:

s1, machining a groove on the working surface of the cutter point of the cleaver along the width direction of the working surface by adopting high-precision electric spark, picosecond laser or femtosecond laser;

and S2, machining the roughness of the inner wall surface of the groove by adopting micro electric spark discharge.

The radius of the semicircular groove is extremely tiny, the requirement that the radius is 0.005 mm-0.04 mm can be met under the existing technical condition, only laser and micro electric spark discharge machining are carried out, the roughness of the laser machining is not controlled, and burrs exist. The minimum machinable diameter of the micro electric discharge machining is phi 0.007mm (namely the radius is R0.0035mm), the requirement on the size of a semicircular groove is completely met, meanwhile, the machining roughness of the micro electric discharge machining can be controlled between Ra0.1-Ra0.6, and the requirement on the surface roughness required by ultrasonic energy transfer can be met.

The invention has the beneficial effects that: the invention has the advantages of being beneficial to the ultrasonic energy coupling of the riving knife, having good formation of gold wire (or aluminum wire or copper wire) welding spots and welding spot shapes and meeting the requirement of high-precision semiconductor packaging.

Drawings

FIG. 1 is a first schematic structural diagram of a deep cavity welding chopper according to an embodiment of the present invention;

FIG. 2 is a longitudinal cross-sectional view of FIG. 1;

FIG. 3 is an enlarged view at A in FIG. 2;

FIG. 4 is a second schematic structural view of the deep cavity welding chopper of the embodiment of the present invention;

fig. 5 is an enlarged view at B in fig. 4.

Description of reference numerals:

10. a riving knife handle; 11. a through hole; 20. the tip of the riving knife; 21. threading holes; 22. and (4) a groove.

Detailed Description

The embodiments of the present invention will be further described with reference to the accompanying drawings.