EMI Shielding and SinterInks for 5G RF components

RF com­po­nents are an inte­gral part of the 5G rev­o­lu­tion. The amount of RF front end com­po­nents required has dou­bled dur­ing the tran­si­tion from 4G to 5G. This, obvi­ous­ly, goes in the oppo­site direc­tion of the indus­try’s minia­tur­i­sa­tion trend where every­thing needs to be small­er and denser. 

That’s why RF anten­nae trends require thin­ner and more effi­cient pack­ages. Inte­grat­ed Anten­na in Pack­age 5G com­po­nents are rapid­ly mov­ing from asym­met­ric and stacked anten­nae to ultra thin hybrid and fan out with mul­ti band and high­er fre­quen­cies. This allows, at least, keep­ing devices on a sim­i­lar size as with pre­vi­ous generations.

But high­er fre­quen­cy sig­nal trans­mis­sion, increas­ing com­po­nent count and adding more pro­cess­ing and func­tion­al­i­ty in the same space come at a cost and with ele­vat­ed design and reli­a­bil­i­ty requirements.

That’s where Pack­age lev­el EMI shield­ing comes in.

What is EMI Shielding?

Elec­tro­Mag­net­ic Inter­fer­ence Shield­ing is the reflec­tion or absorp­tion of Elec­tro­mag­net­ic radi­a­tion through the use of a shield­ing mate­r­i­al. It pro­tects sig­nals from being exter­nal­ly dis­rupt­ed while also pre­vent­ing them from inter­fer­ing with sur­round­ing components. 

In the elec­tron­ics indus­try and in sim­ple terms it is the prac­tice of iso­lat­ing the sig­nal of com­po­nents so that they don’t inter­fere with each other.

Board level shielding

Tra­di­tion­al­ly this sep­a­ra­tion is being done on a Board lev­el. You would sol­der a lid or con­duc­tive enclo­sure on the board, cov­er­ing the com­po­nent and sep­a­rat­ing it from what­ev­er you want­ed to be sep­a­rat­ed. As you can imag­ine enclo­sures are heavy and require a lot of board space, lim­it­ing the design flexibility. 

Remem­ber when we said RF com­po­nents dou­bled in 5G appli­ca­tions? Well, with tra­di­tion­al board lev­el shield­ing you would have to dou­ble enclo­sures, weight and space. If this does­n’t sound great it’s because it isn’t.

Package level EMI Shielding

Enter Pack­age lev­el EMI shield­ing. In a stroke of genius engi­neers decid­ed that we don’t need enclo­sures any­more. We can fend those sig­nals with­in the pack­age itself. 

How? We dig walls in the mold­ed pack­age, we fill them with EMI shield­ing pastes and then we final­ly cov­er them with a con­for­mal coat­ing. This way we can have mul­ti­ple con­duc­tive par­ti­tions with­in the pack­age and iso­late mul­ti­ple com­po­nents with­in the same pack­age, lead­ing to high den­si­ty designs and miniaturisation.

Pack­age lev­el EMI shield­ing enables Fara­day cages direct­ly applied at the pack­age lev­el. This reduces the dimen­sions and weight of the over­all design and pro­vides a com­pact and effec­tive shield­ing method.

We, as Caplinq, can aid you with most of these steps. From Die attach mate­ri­als to Encap­su­lants and Mold­ing com­pounds, we have solu­tions for every step of the semi­con­duc­tor pack­ag­ing process. Now we are hap­py to announce that we also pro­vide Henkel’s newest and great­est EMI shield­ing materials.

After cut­ting the wall and in order to jet dis­pense EMI shield­ing there are elec­tri­cal­ly con­duc­tive, void free pastes such as EMI 3620FA that can be used to fill trench­es and gaps and exhib­it no cracks or delam­i­na­tion after reli­a­bil­i­ty testing.

The next step is to coat and cure the pack­age. The con­for­mal shield­ing needs to have a uni­form coat­ing thick­ness with­in 3–10um, be applied by atom­iz­ing spray and shield in a range between 10MHz and 10GHz. These are all prop­er­ties of EMI 8880S, a sprayable, effec­tive mate­r­i­al with extreme­ly low resis­tiv­i­ty and good laser mark­ing vis­i­bil­i­ty. All in all, if you are inter­est­ed in tran­si­tion­ing to pack­age lev­el shield­ing, we got you covered.

Printed Silver interconnects

EMI shield­ing is not the only solu­tion for the minia­tur­i­sa­tion of pack­ages. Print­ed sil­ver inter­con­nects with Sin­terINKS (Sin­ter­ing Inks) are also a great solu­tion to replace wire bond inter­con­nects, print high­ly con­duc­tive cir­cuits and at the same time have improved RF per­for­mance at fre­quen­cies up to 110GHz. 

These mate­ri­als can help dras­ti­cal­ly reduce the pack­age foot­print in height and width and and also oper­ate in high­er fre­quen­cies. But we are slow­ly start­ing to drift away from the scope of this blog. 

EMI Shield­ing and Sin­terinks will be thor­ough­ly dis­cussed and pre­sent­ed by Henkel’s Busi­ness Devel­op­er, Ruud de Wit dur­ing the upcom­ing Microtech 2021.

Smart Elec­tron­ics’ mar­ket trends like 5G are dri­ving advanced semi­con­duc­tor pack­ag­ing inno­va­tions towards high­er func­tion­al­i­ty, enhanced con­nec­tiv­i­ty at high­er fre­quen­cies, small­er form fac­tors (minia­tur­i­sa­tion) and reduced pow­er con­sump­tion. Espe­cial­ly for next gen­er­a­tion RF devices includ­ing anten­nas, pack­age lev­el EMI shield­ing, and short­er inter­con­nects are key to enable next gen­er­a­tion mmWave devel­op­ments run­ning at increas­ing fre­quen­cies above 100 GHz.

Ruud De Wit, Henkel Elec­tron­ic Materials

This is part of Ruud’s abstract for the upcom­ing MicroTech 2021 Online Con­fer­ence on Het­ero­ge­neous Inte­gra­tion. This online event takes place on the 25th of March and is organ­ised by iMAPS UK. MicroTech 2021 is the Annu­al IMAPS-UK Con­fer­ence which focus­es on key emerg­ing mar­kets and their asso­ci­at­ed tech­no­log­i­cal challenges.

Even though we are not IMAPS mem­bers yet, we can con­fi­dent­ly sug­gest attend­ing. We joined mul­ti­ple online webi­na­rs and work­shops over the last year and have thor­ough­ly enjoyed them. They have suc­cess­ful­ly adapt­ed to the cur­rent remote cir­cum­stances and there’s always some­thing new and excit­ing to learn. That’s why we are hap­py to sup­port and pro­mote them for their great work on shar­ing and sup­port­ing indus­try knowl­edge and developments.

Want to learn (even) more about EMI shield­ing and all things semi­con­duc­tor? Fol­low our blog or con­tact us for addi­tion­al information.