CA2622581C

CA2622581C - Laminated substrate for mounting electronic parts

Info

Publication number: CA2622581C
Application number: CA2622581A
Authority: CA
Inventors: Eckhard Ditzel; Siegfried Walter; Manfred Gresch
Original assignee: WC Heraus GmbH and Co KG
Current assignee: Heraeus Deutschland GmbH and Co KG
Priority date: 2005-09-14
Filing date: 2006-09-08
Publication date: 2011-11-22
Anticipated expiration: 2026-09-08
Also published as: EP1925192A1; CN101263750A; KR20080045199A; DE102005044001B3; EP1925192B1; ATE555642T1; PT1925192E; JP5339908B2; JP2009508343A; CN101263750B; KR101161047B1; US8153232B2; CA2622581A1; US20080220202A1; WO2007031241A1; MY157279A

Abstract

The invention relates to a laminated substrate producing method for mounting semiconductor chips, wherein at least respective metal and plastic structure films having respective different recurrent contour are laminated together in such a way that a material strip is obtained and said lamination is followed by perforations or cuttings, the inventive method is characterised by at least one of the following steps: A) the films are structured in such a way that the superposition thereof makes it possible to obtain the areas which are devoid of overlap through the total thickness thereof; B) the films are not laminated through the total thickness of the laminate in partly recurrent areas; and C) the reccurent cross-sections of the reccurent contours are curved from the surface of the laminated strip starting from said laminate.

Description

Laminated Substrate for Mounting Electronic Parts Description This invention relates to a laminated substrate producing method for mounting semiconductor chips of at least respective metal and plastic structure films, as well as strip-shaped laminates as a pre-liminary stage of the substrates.

According to DE 195 21 022, one metal film sheet and one plastic film sheet are separately stamped and thereafter bonded with each other to an "endless strip" wherein preferably guiding pins engage in superposed position markings of the film sheets to be bonded with each other.

In clean room applications, the laminate abrasion occurring during the isolation of the substrates is an undesirable contamination.

The sensitivity of ever more miniaturized electronic parts to mechanical stresses is also problematic.
It is the object of this invention to better protect electronic parts against mechanical stresses, reduce the contamination through laminate abrasion upon isolation, provide simplifications for processing such laminate substrates, and enable more flexible application potentials for the substrates.

The following features are suitable for the solution of the problem, in particular in combination with a plurality of these features:

A) The films are structured in such a way that the superposition thereof makes it possible to obtain the areas which are devoid of overlap through the total width thereof.

B) The films are not laminated through the total width of the laminate in partly recurrent ar-eas.

C) The recurrent segment of the recurrent contours are bent out of the surface of the lami-nated strip starting from said laminate.

Solutions according to the invention are described in the independent claims.
Preferred embodi-ments are found in the dependent claims.

When films according to feature A) or B) are structured in such a way that the superposition thereof makes it possible to obtain the areas which are devoid of overlap or lamination through the total thickness thereof, these areas enable a complete removal of one or a plurality of films through the total thickness of the laminated strip so that the laminated strip in this area consists exclusively of the remaining film(s) and all structuring steps are performed on non-laminated material.

A strip-shaped laminate is thus provided of at least respective metal and plastic structure films, whose films have respective different recurrent contours and which has areas in which the struc-tured films are devoid of overlap through the total width of the strip, or a film of the laminate is struc-tured in non-connected contours.

When recurrent cross-sections of the recurrent patterns are curved from the surface of the lami-nated strip starting from the laminate according to feature C), free areas are thereby created in the surface of the laminated strip and with said areas, in turn, the same effect can be achieved as with features A) and B) on the one hand, namely the removal of one or a plurality of films through the total width of the laminated strip, maintaining one or a plurality of films.
On the other hand, the curved segments are suitable to fix receiving parts in place and protect them from mechanical stress.

Any tongues projecting from the surface of the strip are prone to damage when winding the strip and they tend to get caught when unwinding the strip. These problems can be eliminated with spacers.
A strip-shaped laminate is thus provided of at least respective metal and plastic structure films, whose films have respective different recurrent contours and which has segments curved from its base surface which are particularly designed as tongues or spacers.
In a preferred embodiment, a plurality of tongues is arranged as bands or side walls of a support, in particular a socket.

The tongues, arranged in particular in the form of a support, enable a particularly precise assembly.
To fully utilize the offered precision, reference perforations are punched into a non-laminated area of a film, particularly a metal film, whose tolerance versus the known laminated guide perforations can be kept smaller. Perforations in a non-laminated area are particularly suitable as reference perfora-tions since their tolerance of 0.01 mm versus the known positional markings (guide perforations) (tolerance: 0.03 mm) is once more significantly reduced and enables a more precise fitting of the electronic parts. It has proven successful to punch reference perforations after the lamination.

All these laminates are suitable for providing laminated substrates for mounting semiconductor chips and are intermediate products in methods for producing substrates with at least respective metal and plastic structure films.

In a method, recurrent cross-sections of the recurrent contours are curved from the surface of the laminated strip starting from said laminate; in particular, recurrent cross-sections are curved to tongues or spacers.

Ideally, the films are structured in such a way that the superposition thereof makes it possible to obtain the areas which are devoid of overlap through the total width thereof.
Accordingly, the films are not laminated through the total width of the laminate in partly recurrent areas.

A crucial method provides that a film of the laminated strip is separated into non-connected con-tours. This renders it possible that strip-shaped laminates are separated for isolation to substrates in those areas in which a film was interrupted.
In preferred embodiments, = the laminated substrates are carriers for semiconductor chips;
= the structured metal film is punched or etched;
= the plastic film is punched;
= the plastic film is fiber-reinforced, particularly fiberglass-reinforced;
= the respective different recurrent contours are punched in a punching device with a replace-able punching part;
= a free cutting is provided in the metal film to expose the subsequent tongues;

= the contour is punched for the subsequent spacers in the metal film without free cutting;
= the guide perforations for alignment of the films superposed are punched with the same punching tool into the metal film as well as into the plastic film;
= in the plastic film, free cuttings are punched in areas which are arranged around the subse-quent tongues;
= in the plastic film, free cuttings are punched in areas which are arranged around the subse-quent spacers;
= in the plastic film, free cuttings are punched in areas which are arranged around the subse-quent reference perforations;
= recesses are punched on the edge of the plastic film;
= the respective different recurrent contours are punched in a punching device with replace-able punching modules;
= the films are laminated with an adhesive to a strip;
= the cuttings produce cross-sections which are curved;
= two or three films are structured in such a way that the superposition thereof makes it possi-ble to obtain the areas which are, at least with regard to one film, devoid of overlap through the total thickness thereof, or that at least one film is not laminated through the total thick-ness of the laminate in partly recurrent areas;
= two differently structured metal films are separated from each other through one plastic film which is differently structured therefrom;
= the strip-shaped laminate consists of a metal structure film between two plastic structure films, wherein the films have different recurrent contours;
= a metal structure film is arranged between two identically structured plastic films;
= the recurrent cross-sections of the recurrent contours are curved to strip-shaped tongues from the surface of the laminated strip starting from the laminate;
= the tongues are curved perpendicularly or nearly perpendicularly, particularly in an range be-tween 80 and 1000 from the surface of the strip;
= metallic tongues are curved through the plane of a free cutting of the plastic film;
= the contours of the metallic tongues as well as the free cutting in the plastic film are gener-ated before the lamination of the plastic film with the metal film;
= recurrent cross-sections of the recurrent contours are curved to Z-shaped spacers from the surface of the laminated strip starting from this laminate;
= the spacers project higher from the surface of the strip than the tongues;

= a method comprises at least two of the steps A, B, and C;
= a method comprises the three steps A, B and C;
= the sequence of the steps A, B, and C is complied with;
= a film is separated into non-connected contours in those areas which are devoid of overlap with the other film through the total width;
= modules are produced in the laminate which are held in the laminate solely via metallic con-nections;
= strip-shaped laminates for isolation to substrates are separated in those areas in which a film was interrupted;
= the strip-shaped laminate comprises two structured metal films and one structured plastic film arranged between the metal films, wherein the films each have different recurrent pat-terns.

According to the invention, it is made possible to curve metallic tongues through the plane of a free cutting of a plastic film because the contour for the tongues and the free cuttings in the respective films were already set up before lamination. The only remaining metallic connections of the modules permit a residue-free separation of the modules during isolation which is important for high-purity applications. Thus will be prevented that, during isolation, dust is generated due to severing the plastic-containing connections.

Furthermore, this renders it possible to arrange a plurality of tongues to each other such that they form a support for receiving electronic parts. The tongues are the walls of the support. By means of the tongues, the support can be designed as a socket which holds electronic parts. Modules with sockets for electrical parts can be produced therewith. Still on the strip, the modules can be assem-bled with particularly high precision before they are isolated.

In the following, the invention is illustrated with reference to the drawings:
Figure 1 shows a punched metal film in a top view;
Figure 2 shows a punched plastic film in a top view;
Figure 3 shows a laminate from the metal film according to Figure 1 and the plastic film ac-cording to Figure 2 in a top view;

Figure 4a shows the laminate from Figure 3 in a top view, with curved-up tongues and curved-up spacers;
Figure 4b shows a section of a still connected module from Figure 4a;
Figure 4c shows the laminate from Figure 3 in a side view, with curved-up tongues and curved-up spacers, illustrating the tongues and spacers being curved from the surface of the laminate;
Figure 4d shows a three-dimensional view of the laminate from Figure 3 with curved-up tongues and curved-up spacers, and with round guide perforations;
Figure 5 shows the isolation of the laminated modules from the laminated strip.

The following illustrates the steps of the production process with the sequence of the Figures.

For the production of a metal film 20 according to Figure 1, a punching sequence is performed in a punching device providing recurrent contours 21, 22, 23, 24 in the form of punched images accord-ing to Figure 1. Analogously, metal films according to Figure 1 can also be structured by etching without the spacer outline. According to Figure 2, other contours 25, 26, 27, 28 are analogously punched in the form of punched images with another punching tool into a plastic film 19. The films according to Figure 1 and Figure 2 are laminated by means of their guide perforations 22 to a met-al/plastic film composite 6 according to Figures 3 and 4c. The outlines 21, 22, 23, 24, 25, 26, 27, 28 of the metal film 20 and of the plastic film 19 are laminated, with an accurate fit, to structures which produce the structure of the subsequent modules 18. From the laminate 6 according to Figure 3, the plastic connections 10 are separated in the area of the tongues 24. The tongues 24 are curved up thereafter. The curved-up tongues 1 are shown in Figures 4a, b, c and d. The laminate according to Figures 4a, b, c, d is suitable for the assembly with electronic parts and can be isolated to the indi-vidual modules 18 according to Figure 5 by severing the metallic connections 5 at the separation points 15 and 16.

Figures 1 to 5 show as contour 23 the free cutting 23 around the subsequently curved tongues 1.
Between the contours 23 which produce the free cuttings 23, connections 5 are provided which maintain the connection of the islands - generated by the free cuttings 23 -of the subsequent modules 18 with the outer area of the metal film 20. The contour 21 of the spacers is a punched cutting 21 for spacer 2. The contours 22 are punched-out guide perforations 22. The metal film 20 is only lanced in the area of spacers 2. For this, the spacers 2 are pushed back into the surface of the metal film after the cutting 21 was made with an accurate fit. The contour 24 defines the tongues 1 subsequently curved.

Figures 2 to 5 show the contours 25, 26, 27, 28 in the plastic film 19 as the free cuttings 25, 26, 27, 28 in the area of the subsequent tongues 24, spacers 2, reference perforations 4 and the punched-out guide perforations 22. The free cuttings thus expose tongues 24, the spacers 2 and the refer-ence perforations 4. Moreover, recesses 28 are punched out at the edge. The contour 25 is a free cutting in the plastic film 19 for subsequent punching of the reference perforations 4 into the metal film 20. The contour 26 is a free cutting in the plastic film 19 which enables subsequent curving of the punched tongues 24 to tongues 1. Between the contours 26 which generate the free cuttings 26, connections 10 and 11 are provided which maintain the connections of the outer area of the plastic film 19 with the islands - produced by free cuttings 26 - of the subsequent modules 18. Analogous-ly to contour 26, the contour 27 is a free cutting which enables later curving of the spacers through the plane of the free cutting. The contour 28 is used as free cutting with the free cuttings 26 accord-ing to contours 26 for the subsequent isolation of the modules through the subsequent free cuttings 13 (Figure 4b).

Figures 1 to 3 show metallic connections 5 which are not covered by the plastic film 19 due to the free cuttings 26. The guide perforations 22 of the metal and plastic film are laminated superposed and with an accurate fit in laminate 6 as guide perforations 9. Due to the free cuttings 23, the plastic connections 10 and 11 are not laminated on the metal film.

After lamination of the films 19 and 20 to a laminate 6 according to Figure 3 (and 4c), first the con-nections 10 and 11 of the plastic film 19 are punched out at the separation points 14 and thereafter the tongues 24 and the spacers 21 are curved from the surface of the laminate.
Figures 4a, b, c, d show tongues 1 and spacers 2 curved from the surface. The free cutting 3 is one part of the free cutting 26 which prevents that tongue 1 fits closely at the cutting edge of the plastic film 19. This provides a particularly preferred precision regarding the curving of the tongue in accordance with the invention. After the curving actions, the remaining laminate connections 13 are cut free. The module 18 is thus completed in terms of its plastic lamination and is still held in the strip structure only via the metal film 20, actually via its metallic connections 5 (according to Figures 4a and 4d) at the separation points 15, 16 and 17, as shown in Figure 5. The modules of the carrier strip accord-ing to Figure 5 are suitable for automatic assembly. In this case, separate reference perforations 4 are produced with a precision in the area of 0.01 mm which are punched into the metal film after curving the tongues 24 to 1 and spacers 21 to 2. The reference perforations 4 allow precise assem-bly of the modules 18 with parts. The position of the curved tongues 1 is particularly precisely de-fined by the reference perforations 4. Such an arrangement is particularly suitable for the assembly with electronic parts. In addition to the known contacting via the base of the metal film, the embodi-ment with tongues according to the invention also enables contacting via the tongues 1.

The possibility according to the invention to contact not only via the base surface of the metal film but also allow contacting via the sides opens up new mounting and assembly possibilities as well as the application of electronic parts of a new design. Furthermore, the tongues 1 allow mechanical fixation as well as protection against mechanical stresses. Protection, in this case, is provided not only for additional production methods - such as for instance, injection-molding around mounted parts - but also in the final application. The holding function of tongues 1 is not limited to electronic parts.

After assembly with the parts, the modules 18 held in the metal film 20 are isolated. Isolation is pro-vided by cutting free the remaining metallic connections at the separation points 15, 16 and 17 so that no laminate is cut in this step and this process step can be performed under clean room condi-tions.

List of Reference Symbols 1) Curved tongues 2) Curved spacers 3) Free cutting of the plastic film in the curving area of the tongues 4) Reference perforation punched after curving 5) Metallic connection of the modules 8) Laminated substrate 9) Guide perforations (laminated with accurate fit) 10) Connection of the plastic film 11) Connection of the plastic film 13) Separation point of the laminate connection 14) Separation point of the plastic connection 15) Separation point 16) Separation point 17) Separation point 18) Module 19) Plastic film 20) Metal film 21) Contour of spacers 22) Guide perforations 23) Free cutting in the metal film around tongues still to be curved 24) Tongues (punched/flat) 25) Free cuttings in the plastic film for subsequent punching of the reference perforations 26) Free cuttings in the plastic film for subsequent curving of the tongues 27) Free cuttings in the plastic film for subsequent curving of the spacers 28) Free cutting in the plastic film for subsequent isolation of the modules

Claims

1. Method for producing laminated substrates for mounting semiconductor chips, comprising the steps of:
providing a metal film comprising recurrent contours; and providing a plastic film comprising other contours;
wherein the metal film and the plastic film, having respective different recurrent contours, are laminated to the laminated substrates which produce a structure of subsequent modules; and wherein said lamination is followed by perforations or cuttings, characterized in that recurrent segments are bent out of the surface of the laminated substrate; and the perforations or cuttings are done so that:
areas are obtained, which are devoid of overlap of the plastic film on the metal film through the total width of the laminated substrates;
the modules are only held in the laminated substrates via metallic connections of the metal film; and the metallic connections are arranged in the devoid area.

2. Method according to claim 1, characterized in that recurrent segments are curved to tongues (1).

3. Method according to claim 1 or 2, characterized in that recurrent segments are curved to spacers (2).

4. Method according to any one of claims 1 to 3, characterized in that reference perforations (4) are punched into a metal film (20).

5. Method according to any one of claims 1 to 4, characterized in that a first isolation of at least one first film (19) is performed in modules (18) separated from each other while at least one film (20) maintains the strip structure.

6. Method according to claim 2, characterized in that the tongue (1) is curved through the plane of a free cutting (26).

7. Method according to claim 2 or 6, characterized in that the segment for producing the tongue (1) is provided by structuring the metal film (20) before lamination with the plastic film (19).

8. Method according to any one of claims 1 to 7, characterized in that the free cutting (26) in the plastic film is provided by structuring the plastic film (19) before lamination of the plastic film (19) with the metal film (20).

9. Strip-shaped laminated substrate from at least respective metal and plastic structure films (20, 19) produced according to any one of claims 1 to 8, wherein the films have respective different recurrent contours (23, 26), characterized in that the strip comprises modules (18) which are solely held by metallic connections (5) in the laminated substrate.