DE102019111437B4 - Method for producing an electronic intermediate product and method for producing an electronic component - Google Patents

Abstract

Method for producing an electronic intermediate product (10) for later connecting, in particular sintering and/or soldering and/or gluing, to a substrate and/or a semiconductor component, comprising the steps: a) structuring a metal element (20) in such a way that a first Contacting section (21) and at least one second contacting section (22) are formed, with at least one separating joint (31) being formed in sections between at least two contacting sections (21, 22) by complete material removal between the at least two contacting sections (21, 22) and the at least two contacting sections (21, 22) are connected to one another by at least one connecting web (26);b) at least partially applying a contacting material (40) to the at least two contacting sections (21, 22);c) at least partially introducing a temporary adhesive (50 ) into the parting line (31) in such a way that the two contacting sections (21, 22) are additionally connected, the temporary adhesive (50) containing 20 - 45% by weight of thermoplastic polymer and 40 - 70% by weight of organic solvent and 10 - 25% by weight of inorganic filler particles and 0 - 0.5% by weight of further additives; d) removing the at least one connecting web (26).

Description

The invention relates to a method for producing an electronic intermediate product for later connection, in particular sintering and/or soldering and/or bonding, to a substrate and/or a semiconductor component. The invention also relates to a method for producing an electronic component.

It is known from the prior art to use adhesive tapes or transfer films in order to be able to equip electronic components in one step before they are soldered or sintered, for example. Furthermore, it is known to grip and move several components at the same time with mechanical grippers. Alternatively, the electronic components are moved one after the other, which leads to increased process time.

In CN 101958257 A a method for producing an electronic component is disclosed. An epoxy resin is introduced into recesses so that a type of frame or casting compound is formed with the help of the epoxy resin when the electronic component is completely dried and finished. The epoxy resin is therefore present in the fully installed state, ie in the state connected to a semiconductor element.

In US 2018/0116080 A1 However, a machine for the automated assembly of circuit boards is disclosed. In connection with the circuit board assembly machine, it is stated that individual components of the circuit board to be assembled are automatically fed using feeder belts, so that the components removed from the belts can then be soldered in automatically.

Based on the above, it is the object of the present invention to provide a method for producing an electronic intermediate product for later connection to a substrate and/or a semiconductor component, according to which it is possible to equip several electronic components at the same time, with the process time and the material Effort should be minimized.

It is also an object of the present invention to provide a method for producing an electronic component. In particular, an electronic intermediate product produced according to the invention should be used in this process.

According to the invention, this object is achieved with regard to the method for producing an electronic intermediate product by the subject matter of claim 1 and with regard to the method for producing an electronic component by the subject matter of claim 6.

1. a) Strukturieren eines Metallelements derart, dass ein erster Kontaktierungsabschnitt und mindestens ein zweiter Kontaktierungsabschnitt gebildet werden, wobei zwischen mindestens zwei Kontaktierungsabschnitten durch vollständigen Materialabtrag zwischen den mindestens zwei Kontaktierungsabschnitten abschnittsweise mindestens eine Trennfuge ausgebildet wird und die mindestens zwei Kontaktierungsabschnitte durch mindestens einen Verbindungssteg miteinander verbunden sind;
2. b) zumindest abschnittsweises Auftragen eines Kontaktierungsmaterials auf die mindestens zwei Kontaktierungsabschnitte;
3. c) zumindest abschnittsweises Einbringen eines Temporär-Klebstoffes in die Trennfuge derart, dass die beiden Kontaktierungsabschnitte zusätzlich verbunden werden, wobei der Temporär-Klebstoff 20 - 45 Gew.-% thermoplastisches Polymer und 40 - 70 Gew.-% organisches Lösemittel und 10 - 25 Gew.-% anorganische Füllstoffpartikel und 0 - 0,5 Gew.-% weitere Additive aufweist;
4. d) Entfernen des mindestens einen Verbindungsstegs.

Im Schritt a) wird ein Metallelement derart bearbeitet, dass mehrere, d.h. mindestens zwei, Kontaktierungsabschnitte gebildet werden. Hierzu wird in ein Metallelement mindestens eine Materialausnehmung eingebracht, so dass mindestens zwei Kontaktierungsabschnitte gebildet werden.The invention is based on the idea of specifying a method for producing an electronic intermediate product for later connection, in particular for later sintering and/or soldering and/or bonding, to a substrate and/or a semiconductor component, the method according to the invention comprising the steps:

1. a) Structuring a metal element in such a way that a first contacting section and at least one second contacting section are formed, with at least one parting line being formed in sections between at least two contacting sections by completely removing material between the at least two contacting sections and the at least two contacting sections being connected to one another by at least one connecting web ;
2. b) at least partially applying a contacting material to the at least two contacting sections;
3. c) at least partially introducing a temporary adhesive into the joint in such a way that the two contacting sections are additionally connected, the temporary adhesive containing 20 - 45% by weight of thermoplastic polymer and 40 - 70% by weight of organic solvent and 10 - 25 % by weight of inorganic filler particles and 0 - 0.5% by weight of further additives;
4. d) Removing the at least one connecting bar.

In step a), a metal element is processed in such a way that several, ie at least two, contacting sections are formed. For this purpose, at least one material recess is introduced into a metal element, so that at least two contacting sections are formed.

If the metal element is to have more than two contacting sections, i.e. at least three contacting sections, separating joints can be formed at least in sections between at least three contacting sections. When structuring, in particular when processing, a metal element, a connecting web must also be formed between at least two contacting sections. A connecting web causes the at least two contacting sections to be connected to one another at least in sections even after a separating joint has been formed.

A separating joint is to be understood as a complete removal of material between two contacting sections. In other words, the parting line is a complete gap, in particular a gap or slot, between two contacting sections.

The metal element is preferably an element made of copper or a copper alloy. In other words, the metal element is preferably made of a copper material or a copper alloy material.

In step b), a contacting material is applied to the at least two contacting sections. It is possible for the contacting material to cover the entire contacting section. In a further embodiment of the invention, it is conceivable that a section free of contacting material is formed at least on the edge of the contacting section.

The contacting material can be, for example, a sintering paste and/or a soldering paste and/or a preform made of solder and/or a sintering paste. Furthermore, the contacting material can be a diffusion solder and/or a conductive adhesive and/or an adhesive.

In step c), a temporary adhesive is introduced into the joint at least in sections in such a way that the two contacting sections are additionally connected. In other words, the temporary adhesive introduced serves as an additional connection between the at least two contacting sections, next to the connecting web.

In other words, the temporary adhesive, which is introduced into the parting line at least in sections, serves to temporarily connect the at least two contacting sections. In other words, this serves as a replacement for a previously formed material section between the at least two contacting sections.

In step d) the at least one connecting bar is removed. As soon as the at least one connecting web is removed, the connection between the at least two contacting sections is made possible, preferably exclusively, by the temporary adhesive introduced into the parting line.

The method according to the invention for producing an electronic intermediate product enables the production of such an electronic intermediate product, which can be assembled on a substrate and/or at least one semiconductor component in a single step. This is particularly advantageous if the individual contacting sections are very small and therefore very difficult to handle. Due to the fixed or connected shape of the individual contacting sections, they can be handled as an electronic intermediate product. In addition, faster loading is achieved.

The connecting web can be removed, for example, using a laser ablation process or using a punching process. A laser ablation process is particularly suitable if the contacting sections of the electronic intermediate product are very small. The temporary adhesive is designed at a distance from the connecting web. This allows the connecting bar to be removed without additionally removing the temporary adhesive.

In step a), a frame can be formed which frames and/or connects the at least two contacting sections at least in sections. Such an embodiment with regard to the structuring/processing of a metal element is particularly advantageous if a power semiconductor with an emitter and gate contacts is to be produced. It is therefore possible to use the method according to the invention in several applications.

The frame can be at least partially, preferably completely, removed in step d). The frame produced preferably serves as an intermediate stabilizer, so that easy handling is possible.

The temporary adhesive can be applied at points into the joint. In particular, it is possible for several temporary adhesive points to be introduced into the parting line. Preferably, the temporary adhesive sections introduced are introduced into the parting line evenly, in particular at equal distances from one another.

It is possible that the temporary adhesive will completely fill the parting line. In such an exemplary embodiment, the contacting sections are particularly well connected to one another.

It is also possible that the temporary adhesive does not completely fill the parting line in terms of the height of the parting line.

It is also possible for the temporary adhesive to be applied in strips into a joint.

Using the method according to the invention, an electronic intermediate product can be produced for later connection, in particular for later sintering and/or soldering and/or bonding, to a substrate and/or at least one semiconductor component.

The electronic intermediate product has a first contacting section and at least one second contacting section, a parting line being formed between the at least two contacting sections and the at least two contacting sections being connected to one another at least in sections by means of a temporary adhesive.

It is possible for the electronic intermediate product to have more than two contacting sections. In such a case, the electronic intermediate product can have several separating joints.

The temporary adhesive has 20 - 45% by weight of thermoplastic polymer and 40 - 70% by weight of organic solvent and 10 - 25% by weight of inorganic filler particles and 0 - 0.5% by weight of other additives.

The thermoplastic polymer of the prefixing agent has, for example, a glass transition temperature of 60 to 120 ° C. The glass transition temperature is determined using DDK, namely dynamic differential calorimetry, or DSC, namely differential scanning calorimetry, at a heating rate of 10 K/minute.

The thermoplastic polymer can in particular be (meth)acrylic copolymers. The molecular weight range of the thermoplastic (meth)acrylic copolymers can be 35,000 to 70,000 g/mol (Mw=35,000 to 70,000 g/mol). The molecular weight range is to be determined using gel permeation chromatography (GPC). The following applies to gel permeation chromatography: polystyrene gel as the stationary phase, tetrahydrofuran as the mobile phase, polystyrene standards.

The 40 to 70% by weight of organic solvents contain 30 to 100% by weight of terpineols.

The 10 to 25% by weight of inorganic filler particles have a particle size (d50) of 5 to 20 µm, preferably 5 to 10 µm. These inorganic filler particles can be, for example, aluminum oxide and/or silicon dioxide. The particle size (d50) is preferably determined using a laser diffraction method.

The 0 to 0.5% by weight of further additives can be, for example, wetting agents.

With the help of a temporary adhesive with the specified composition, uniform adhesive dots with a calculable final height can be created.

The temporary adhesive sections can be introduced into the at least one parting line by dispensing or dipping or jetting.

In the electronic intermediate product, the previously formed at least one connecting web is removed.

A separation gap can be completely formed between at least two contacting sections, which is only partially bridged by the temporary adhesive. In other words, the at least two contacting sections are preferably connected to one another only by a temporary adhesive section. In other words, at least two contacting sections are held together, at least in sections, by the temporary adhesive, which is located in one/of the parting line.

For example, at least one contacting section is designed to be smaller than at least one further contacting section and is arranged completely in a recess of the further contacting section and at a distance from this further contacting section. In such a design, the smaller contacting section, which is surrounded by the further (larger) contacting section, can be a gate pad.

The small or smaller contacting section is preferably circular. The spacing of the smaller contacting section from the further contacting section takes place by means of the parting line. The parting line can be ring-shaped.

A contacting section, in particular the small contacting section, of an electronic intermediate product can be a gate or an emitter or a drain or a source.

The electronic intermediate product can include at least one gate pad and at least one emitter pad.

The electronic intermediate product can be designed as a clip or contact bridge or connector or as an arrangement of several contacts to form an electronic component.

Another aspect of the invention relates to a method for producing an electronic component.

• k) Bereitstellen eines erfindungsgemäß hergestellten und bereits beschriebenen elektronischen Zwischenprodukts;
• l) Aufsetzen des elektronischen Zwischenprodukts auf ein Substrat und/oder auf mindestens ein Halbleiterbauteil;
• m) Verbinden des elektronischen Zwischenprodukts mit dem Substrat und/oder mit mindestens einem Halbleiterbauteil und Bilden des Elektronik-Bauteils.

The procedure includes the steps:

• k) providing an electronic intermediate product produced according to the invention and already described;
• l) placing the electronic intermediate product on a substrate and/or on at least one semiconductor component;
• m) connecting the electronic intermediate product to the substrate and/or to at least one semiconductor component and forming the electronic component.

Preferably, the temporary adhesive is at least partially removed in step m). When connecting, especially when sintering and/or soldering and/or gluing, the temporary adhesive is reduced. An inert, non-conductive residue of the temporary adhesive may remain, with this temporary adhesive residue no longer sticking.

The method according to the invention for producing an electronic component has, among other things, the advantage that the temporary adhesive does not have to be removed separately, as is the case, for example, with previously known adhesive films. Rather, the temporary adhesive is automatically at least partially removed when connecting the intermediate product to a substrate and/or at least one semiconductor component.

Furthermore, it is possible to bond different contacting sections with the same bonding wire due to the method according to the invention. Ideally, at least one bonding step can be eliminated in the production of the electronic component.

The temporary adhesive is electrically neutral and does not affect the sintering behavior and lifespan of the manufactured electronic component.

The invention is explained in more detail below using exemplary embodiments with reference to the accompanying drawings.

• 1a - 1d verschiedene Schritte zur Herstellung eines erfindungsgemäßen elektronischen Zwischenprodukts gemäß einer ersten Ausführungsform der Erfindung; und
• 2a - 2d verschiedene Schritte zur Herstellung eines erfindungsgemäßen elektronischen Zwischenprodukts gemäß einer zweiten Ausführungsform der Erfindung.

Show in these:

• 1a - 1d various steps for producing an electronic intermediate product according to the invention according to a first embodiment of the invention; and
• 2a - 2d various steps for producing an electronic intermediate product according to the invention according to a second embodiment of the invention.

The same reference numbers are used below for identical and identical components.

The 1a - 1d show the production of an electronic intermediate product 10 according to a first embodiment of the invention.

In a first step a), a metal element 20 is therefore structured in such a way that a first contacting section 21, a second contacting section 22 and a third contacting section 23 are formed.

In this example according to 1a Three contacting sections 21, 22 and 23 are thus formed. The method according to the invention provides for the formation of at least two contacting sections.

A first parting line 31 is formed between the first contacting section 21 and the second contacting section 22. A second parting line 32 is formed between the second contacting section 22 and the third contacting section 23. The three contacting sections 21, 22 and 23 are connected to one another by two connecting webs 26 and 27.

The contacting sections 21, 22 and 23 each have a web shape. A first connecting web 26 is formed at the first ends 24 of the contacting sections 21, 22 and 23. In the example shown, the first ends 24 are each the upper end.

A second connecting web 27 is formed at a second end 25 of the contacting sections 21, 22 and 23.

The separating joints 31 and 32 space the contacting sections 21, 22 and 23 from one another. The parting lines 31 and 32 are essentially slot-shaped. The separating joints 31 and 32 are complete material recesses. The metal element 20 essentially consists of a copper foil. In the 1a - 1b a top view of the individual stages of the electronic intermediate product 10 to be produced is shown.

The metal element 20 is in the 1a formed in one piece. In this case, the metal element 20 consists of the three contacting sections 21, 22 and 23 as well as the connecting webs 26 and 27.

The parting lines 31 and 32 are preferably produced using laser cutting. The originally formed material, which is between The contacting sections 21, 22 and 23 are formed, each completely removed.

In step b) according to the invention, as in 1b is shown, a contacting material 40 is applied to the contacting sections 21, 22 and 23. This can in particular be a sintered material. In the present example, the contacting material 40 is a silver-containing sintering paste. The contacting material 40 is almost completely applied to the contacting sections 21, 22 and 23. Only at the first ends 24 and at the second ends 25 do small sections of material remain that are not provided with contacting material 40. This has the particular advantage that no contacting material 40 is removed when the connecting webs 26 and 27 are subsequently removed. In other words, this serves to save material.

In step c), as in 1c is shown, a temporary adhesive 50 is introduced into the joints 31 and 32 at least in sections. The temporary adhesive sections 50 are punctiform or circular. Due to the temporary adhesive 50, the contacting sections 21 and 22 as well as the contacting sections 22 and 23 are additionally connected to one another.

In step d) according to the invention, as in 1d is shown, the connecting webs 26 and 27 are removed. What remains is the electronic intermediate product 10 produced according to the invention, which consists of the contacting sections 21, 22 and 23 provided with contacting material 40 and the temporary adhesive sections 50.

The produced electronic intermediate product 10 is used for further connection, in particular sintering and/or soldering and/or bonding, to a substrate and/or at least one semiconductor component.

During a subsequent connection process, in particular during sintering, the temporary adhesive 50 is at least partially removed. An inert, non-conductive residue of the temporary adhesive 50 may remain.

The 2a - 2 B show steps a) - d) according to the invention in the correspondingly numbered 2a , 2 B , 2c and 2d .

In 2a a metal element 20 is shown, with a first contacting section 21 being surrounded by a second contacting section 22. The first contacting section 21 has a circular shape. The parting line 31 is essentially annular. At this stage of the process, the ring shape is only interrupted by a connecting web 26.

The second contacting section 22 has a substantially square shape and is larger than the first contacting section 21. Due to the formation of the parting line 31, the first contacting section 21 is formed at a distance from the second contacting section 22. The first contacting section 21 is connected to the second contacting section 22 using a narrow connecting web 26.

2a further shows the formation of a frame 35, which frames the two contacting sections 21 and 22 at least in sections.

How 2 B shows, a contacting material 40 is applied to the second contacting section 22 and to the first contacting section 21. The contacting material 40 is in particular a sintering paste.

The frame 35 is not coated with a contacting material 40. Likewise, the narrow connecting web 26 is preferably not provided with a contacting material.

In 2c It is shown that two points of temporary adhesive 50 are introduced into the essentially annular parting line 31. The temporary adhesive is introduced into the parting line 31 at an equal distance from one another.

In the in 2c In the state shown, the first contacting section 21 is connected to the second contacting section 22 by the first connecting web 26 and by the two sections 50 of the temporary adhesive.

As in 2d is shown, the connecting web 26 is removed. Despite removing the connecting web 26, the first contacting section 21 is still connected to the second contacting section 22.

In addition, the frame 35 is removed so that an electronic intermediate product 10 is present. The first contacting section 21 is in particular a gate pad.

The ones in the 1 - 2d The details shown regarding the production of an electronic intermediate product 10 can be implemented in all possible combinations.

Reference symbol list

10

electronic intermediate product

20

metal element

21

first contacting section

22

second contacting section

23

third contacting section

24

first ending

25

second ending

26

first connecting bridge

27

second connecting bridge

31

first parting line

32

second parting line

35

Frame

40

Contacting material

50

Temporary adhesive

Claims (6)

Method for producing an electronic intermediate product (10) for later connection, in particular sintering and/or soldering and/or bonding, to a substrate and/or a semiconductor component, comprising the steps: a) Structuring a metal element (20) in such a way that a first contacting section (21) and at least one second contacting section (22) are formed, with complete material removal between at least two contacting sections (21, 22) between the at least two contacting sections (21, 22 ) at least one separating joint (31) is formed in sections and the at least two contacting sections (21, 22) are connected to one another by at least one connecting web (26); b) applying a contacting material (40) at least in sections to the at least two contacting sections (21, 22); c) at least partially introducing a temporary adhesive (50) into the parting line (31) in such a way that the two contacting sections (21, 22) are additionally connected, the temporary adhesive (50) containing 20 - 45% by weight of thermoplastic polymer and 40 - 70% by weight of organic solvent and 10 - 25% by weight of inorganic filler particles and 0 - 0.5% by weight of further additives; d) Removing the at least one connecting web (26). Procedure according to Claim 1 , whereby the temporary adhesive (50) is introduced in dots. Procedure according to Claim 1 or 2 , wherein the connecting web (26) is removed by means of a laser ablation process or by means of a punching process. Procedure according to one of the Claims 1 until 3 , wherein in step a) a frame (35) is formed which frames and/or connects the at least two contacting sections (21, 22) at least in sections. Procedure according to Claim 4 , wherein the frame (35) is at least partially, preferably completely, removed in step d). Method for producing an electronic component, characterized by the steps: k) providing an electronic intermediate product (10) produced by a method according to one of Claims 1 until 5 ; I) placing the electronic intermediate product (10) on a substrate and/or on at least one semiconductor component; m) connecting, in particular sintering and/or soldering and/or gluing, the electronic intermediate product (10) to the substrate and/or at least one semiconductor component and forming the electronic component, wherein the temporary adhesive (50) in step m) at least is partially removed.

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