DD140942A1 - METHOD AND ARRANGEMENT FOR MICRO-JOINTING TECHNOLOGY BY MEANS OF LASER - Google Patents

Abstract

The invention relates to a method and an arrangement for the Including microcompounds of thin and thick film circuits Layer combinations, integrated circuits, multilevel micro PCBs, functional microelectronics and other microtechniques. The aim of the invention is by means of laser for any Materials and material combinations on supports and Components without the use of wires easy handling, a low positioning effort, an automatic production as well a simultaneous and / or sequential production too enable. The essence of the invention is a laser beam permeate through the substrate and the trace, which is applied to him, as well as the contact path of a Semiconductor device located below so as to heat that an intimate connection arises, which is a multivalent use makes possible. The application of open and closed-loop control systems under Inclusion of microprocessors represents a modern way of Increase the quality of the joints dar. - Figure -

Description

Title, the invention

Method and arrangement for micro connection technology by means of laser

Field of application of the invention

The invention relates to a method and an arrangement for microconnections of thin and thick film circuits, including layer combinations, integrated circuits, multilevel micro-circuit boards, functional microelectronics and other microtechnologies.

Characteristic of the known technical solutions

It is known that one of the active semiconductor zone (n- or p-doped) outgoing and leading to the external connection, barrier-free contact is subjected to mechanical and thermal stress (bending, soldering) · The contact is low resistance ₈ and the contact resistance remains at the Demands constant (Po Becker, Rme vol. 39 (1973) 1O ₉ S ".444)

The reliability of the semiconductor device is significantly affected by the quality of these joints

It is also known that a compound leads crystal connection wire over two welds (D ₀ Baker, R ₀ Jones, Reliability 5 (1966) H. 5, p 229) *

Gold and aluminum are used as compact and wire-shaped connecting materials {Electronics, 46 (1973) So So 29; SST 18 (1975) 10, So 46 $ IMD ENt EVIi 4/7?) Ο '' "

Here, the known thermo-compression welding occurs (thermal compression bonding, nailhe'ad bonding) to apply "The gold wire passes through a capillary in Schweißkopfο The crystal is preheated and the spherical gold wire end welded _o The welding head moves to the post and welded thereto the gold wire by pressure to »When lifting the welding head, the gold wire is cut off with a hydrogen flame«,

In contrast, in the known ultrasonic welding (Bild der Wissenschaft 8 (1975) p. 2), for example, the aluminum wire is squeezed by the welding head (sonar tube)

The above methods ensure that the bonds are realized one after the other. More productive is the foil bonding technique, as it permits multiple bonds to be performed simultaneously. This technique uses intermediate layers of insulating flexible foil containing a metal conductive pattern and simultaneous bonding of the inner and outer terminals , preferably by soldering or TOB (SST 18 (1975) 10, S ₀ 46, IMD Mt EVM 4/77)

JO allows *

After the internal contacting, the components can also be processed as caseless chips.

In addition to the bonding techniques mentioned, the laser technology is used for soldering and welding or cutting. The disadvantage here is the insufficient utilization of the available power (Bild der Wissenschaft 8 (1975) S, 2),

For soldering small electronic components, for example, 5 W are sufficient, while continuous-wave lasers of> 50 W are used. It is advantageous to use

to concentrate special holograms on several points "This enables simultaneous soldering or bonding and improves the performance reserve. * used. .. ·. '.

Furthermore, it should be attempted to protect the bonding sites by contacted media, for example glass, and to increase the bond capacity by saving steps.

Object of the invention

The aim of the present invention is to develop a method and an arrangement for micro-joining technology by means of laser for any materials and material combinations on irons and components without the use of wires »

The method and the arrangement should be easy to handle, with low positioning effort, universally controllable and thus enable automatic production. It is to be achieved that several compounds are produced simultaneously and / or in succession. This results in a more secure, productive and ef-.

sought more effective connection technology. Explanation of the essence of the invention

The invention is based on the object of making a method and an arrangement for micro-joining technology of any materials and combinations of materials on carriers and components with one another by means of a laser

According to the invention the object is achieved in _s that a laser beam by, for example, the support material through acting and the conductor track which is applied to it as well as the contact path of a semiconductor device that is located below, heated so that · an intimate connection is created ©

The hitherto known technical solutions already show the possibilities to reduce the direct contact and the associated impurities of the weld and connection to a minimum *

Likewise, the reverse effect can occur and the laser beam acts through the device.

By choosing the wavelength of the laser, it can be achieved that the carriers or components do not absorb or absorb weakly. The intimate connection can be assisted and improved by additional pressure, preheating and the use of inert gases. "Connecting by laser with other joining techniques makes multivalent use possible *

A likewise favorable effect can be achieved by correspondingly roughening the surface condition of the conductor tracks on carriers or components or with a specific structure 7 /.

A modern way of increasing the quality of the joints, the use of control and controlled systems unt er-inclusion of microprocessors is ₀ to this the quality of the connection during or after connecting must be measured, or there must be corresponding model functions be present · Then the Microprocessor constantly determine what form _t intensity distribution and wavelength of the laser beam or more directed to the point to be connected laser beams must have, and which positions rays, beams and components occupy »By appropriate actuators can then visited the points to be connected _s the entire assembly einjustiert and the energy supply is metered by the laser and / or the auxiliary energy,

Likewise, the method is particularly suited by the form of automatic parameter adjustment and optimization shown, many connections,. as required, for example, in microelectronics for multi-pole housing, to produce successively or simultaneously

4 '

embodiment

The invention will be explained below with two examples of execution

In Figure 1, the laser beam 1 impinges perpendicularly on the non-absorbing or schwachabsorbierende carrier material 2 · On the lower side of the substrate a plurality of contact points 3 are attached to the _s to travel to successively on a corresponding program from the laser beam "absorb The contact points 3

a large part of the laser energy, heat up to the melting point and conduct the heat to the contact pads 4-j which are diffused on a semiconductor with p-region 5 and n ~ areas 6 The opposite contact pads 5 and contact pads 4 melt and give after switching off the Laser energy an intimate connection over the course of the subsequent cooling process. In order to guarantee a good mechanical connection between the contact points 3 and the contact islands 4 before the laser irradiation ^ both by means of a clamping device? strained «.

With proper selection of a laser as a function of the optical and thermal properties of the semiconductor material used, the connection can · process even after Figo 2 effected * If a film 8 sandwiched between the contact points or ₀ in one of the two opposed contacts material deposited as a solder, so the contact bond can become more durable

Claims (4)

Mlll * t mm claim for invention 1 method and arrangement for micro-joining technology of thin and thick film circuits, including layer combinations, integrated circuits, multi-level microelectrodes, functional microelectronics and other microtechniques, characterized in that a laser beam of certain wavelength penetrates through non-or weakly absorbing support materials or components and in the device or on the Component on which carrier _s connects any applied material combinations between components and between carriers as well as between components and carriers » 2 »method and arrangement according to item 1, characterized in that the carriers and / or components are connected to each other under additional pressure at any desired locations and / or with each othero 3 »Method and arrangement according to item 1, thereby 20. indicates that it has been combined with other micro-joining techniques such as ultrasonic welding, thermocompression bonding, resistance bonding and others 4-0 method and arrangement according to item 1, characterized in that for the preparation of the microcompounds any previously applied materials "on carriers, components or their combinations are used and they have different surface texture o Method and arrangement according to item 1, characterized in that the microcompounds are produced by preheating and with the addition of liquid, solid and gaseous media and their combination. 6ο method and arrangement according to item 1, characterized in that at the points to be joined several laser beams of different wavelengths, laser beams of predetermined geometric intensity distributions and several rays at several points to be joined simultaneously © 7o method and arrangement according to item 1, characterized in that during the connection process "depending on the optical, thermal and other properties power density and power density distribution and geometric position of the laser beam and positioning of the junction continuously and / or in stages as a puncture of the quality of the connection point controlled or "regulated" and the laser wavelength is adjusted " Method and arrangement according to point 1, characterized in that the laser power, laser power density distribution j laser beam guidance and / or the arrangements to be connected by a microprocessor · system or similar electronic devices visited, eingustiert and metered » For this / J page drawing